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freebsd-dev/sys/ufs/ffs/ffs_snapshot.c

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Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
/*
* Copyright 2000 Marshall Kirk McKusick. All Rights Reserved.
*
* Further information about snapshots can be obtained from:
*
* Marshall Kirk McKusick http://www.mckusick.com/softdep/
* 1614 Oxford Street mckusick@mckusick.com
* Berkeley, CA 94709-1608 +1-510-843-9542
* USA
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY MARSHALL KIRK MCKUSICK ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL MARSHALL KIRK MCKUSICK BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
This patch corrects the first round of panics and hangs reported with the new snapshot code. Update addaliasu to correctly implement the semantics of the old checkalias function. When a device vnode first comes into existence, check to see if an anonymous vnode for the same device was created at boot time by bdevvp(). If so, adopt the bdevvp vnode rather than creating a new vnode for the device. This corrects a problem which caused the kernel to panic when taking a snapshot of the root filesystem. Change the calling convention of vn_write_suspend_wait() to be the same as vn_start_write(). Split out softdep_flushworklist() from softdep_flushfiles() so that it can be used to clear the work queue when suspending filesystem operations. Access to buffers becomes recursive so that snapshots can recursively traverse their indirect blocks using ffs_copyonwrite() when checking for the need for copy on write when flushing one of their own indirect blocks. This eliminates a deadlock between the syncer daemon and a process taking a snapshot. Ensure that softdep_process_worklist() can never block because of a snapshot being taken. This eliminates a problem with buffer starvation. Cleanup change in ffs_sync() which did not synchronously wait when MNT_WAIT was specified. The result was an unclean filesystem panic when doing forcible unmount with heavy filesystem I/O in progress. Return a zero'ed block when reading a block that was not in use at the time that a snapshot was taken. Normally, these blocks should never be read. However, the readahead code will occationally read them which can cause unexpected behavior. Clean up the debugging code that ensures that no blocks be written on a filesystem while it is suspended. Snapshots must explicitly label the blocks that they are writing during the suspension so that they do not cause a `write on suspended filesystem' panic. Reorganize ffs_copyonwrite() to eliminate a deadlock and also to prevent a race condition that would permit the same block to be copied twice. This change eliminates an unexpected soft updates inconsistency in fsck caused by the double allocation. Use bqrelse rather than brelse for buffers that will be needed soon again by the snapshot code. This improves snapshot performance.
2000-07-24 05:28:33 +00:00
* @(#)ffs_snapshot.c 8.11 (McKusick) 7/23/00
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/systm.h>
Fixes to track snapshot copy-on-write checking in the specinfo structure rather than assuming that the device vnode would reside in the FFS filesystem (which is obviously a broken assumption with the device filesystem).
2001-03-07 07:09:55 +00:00
#include <sys/conf.h>
ARGH! SBLOCK is not unused. Try to get this right. BBSIZE belongs in <sys/disklabel.h> (but shouldn't be a constant). Define SBLOCK again, using the right math. Sponsored by: DARPA & NAI Labs.
2002-05-12 20:21:40 +00:00
#include <sys/disklabel.h>
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
#include <sys/bio.h>
#include <sys/buf.h>
#include <sys/proc.h>
#include <sys/namei.h>
#include <sys/stat.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/resource.h>
#include <sys/resourcevar.h>
#include <sys/vnode.h>
#include <ufs/ufs/extattr.h>
#include <ufs/ufs/quota.h>
#include <ufs/ufs/ufsmount.h>
#include <ufs/ufs/inode.h>
#include <ufs/ufs/ufs_extern.h>
#include <ufs/ffs/fs.h>
#include <ufs/ffs/ffs_extern.h>
Use thread0.td_ucred instead of proc0.p_ucred. This change is cosmetic and isn't strictly required. However, it lowers the number of false positives found when grep'ing the kernel sources for p_ucred to ensure proper locking.
2002-02-27 19:18:10 +00:00
#define KERNCRED thread0.td_ucred
Silence a warning.
2000-09-17 19:41:26 +00:00
#define DEBUG 1
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
Remove __P.
2002-03-19 22:40:48 +00:00
static int cgaccount(int, struct vnode *, struct buf *, int);
static int expunge(struct vnode *, struct inode *, struct fs *,
int (*)(struct vnode *, ufs_daddr_t *, ufs_daddr_t *, struct fs *,
ufs_daddr_t, int), int);
static int indiracct(struct vnode *, struct vnode *, int, ufs_daddr_t,
int, int, int, int, struct fs *, int (*)(struct vnode *,
ufs_daddr_t *, ufs_daddr_t *, struct fs *, ufs_daddr_t, int), int);
static int fullacct(struct vnode *, ufs_daddr_t *, ufs_daddr_t *,
struct fs *, ufs_daddr_t, int);
static int snapacct(struct vnode *, ufs_daddr_t *, ufs_daddr_t *,
struct fs *, ufs_daddr_t, int);
static int mapacct(struct vnode *, ufs_daddr_t *, ufs_daddr_t *,
struct fs *, ufs_daddr_t, int);
static int ffs_copyonwrite(struct vnode *, struct buf *);
static int readblock(struct buf *, daddr_t);
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
Further fixes for deadlock in the presence of multiple snapshots. There are still more to find, but this fix should cover the common cases that folks are hitting.
2001-05-14 17:16:49 +00:00
/*
* To ensure the consistency of snapshots across crashes, we must
* synchronously write out copied blocks before allowing the
* originals to be modified. Because of the rather severe speed
* penalty that this imposes, the following flag allows this
* crash persistence to be disabled.
*/
int dopersistence = 0;
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
#ifdef DEBUG
#include <sys/sysctl.h>
Further fixes for deadlock in the presence of multiple snapshots. There are still more to find, but this fix should cover the common cases that folks are hitting.
2001-05-14 17:16:49 +00:00
SYSCTL_INT(_debug, OID_AUTO, dopersistence, CTLFLAG_RW, &dopersistence, 0, "");
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
int snapdebug = 0;
SYSCTL_INT(_debug, OID_AUTO, snapdebug, CTLFLAG_RW, &snapdebug, 0, "");
Minimize the time necessary to suspend operations on a filesystem when taking a snapshot. The two time consuming operations are scanning all the filesystem bitmaps to determine which blocks are in use and scanning all the other snapshots so as to be able to expunge their blocks from the view of the current snapshot. The bitmap scanning is broken into two passes. Before suspending the filesystem all bitmaps are scanned. After the suspension, those bitmaps that changed after being scanned the first time are rescanned. Typically there are few bitmaps that need to be rescanned. The expunging of other snapshots is now done after the suspension is released by observing that we can easily identify any blocks that were allocated to them after the suspension (they will be maked as `not needing to be copied' in the just created snapshot). For all the gory details, see the ``Running fsck in the Background'' paper in the Usenix BSDCon 2002 Conference Proceedings, pages 55-64.
2001-12-14 00:15:06 +00:00
int collectsnapstats = 0;
SYSCTL_INT(_debug, OID_AUTO, collectsnapstats, CTLFLAG_RW, &collectsnapstats,
0, "");
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
#endif /* DEBUG */
/*
* Create a snapshot file and initialize it for the filesystem.
*/
int
ffs_snapshot(mp, snapfile)
struct mount *mp;
char *snapfile;
{
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
ufs_daddr_t blkno;
Minimize the time necessary to suspend operations on a filesystem when taking a snapshot. The two time consuming operations are scanning all the filesystem bitmaps to determine which blocks are in use and scanning all the other snapshots so as to be able to expunge their blocks from the view of the current snapshot. The bitmap scanning is broken into two passes. Before suspending the filesystem all bitmaps are scanned. After the suspension, those bitmaps that changed after being scanned the first time are rescanned. Typically there are few bitmaps that need to be rescanned. The expunging of other snapshots is now done after the suspension is released by observing that we can easily identify any blocks that were allocated to them after the suspension (they will be maked as `not needing to be copied' in the just created snapshot). For all the gory details, see the ``Running fsck in the Background'' paper in the Usenix BSDCon 2002 Conference Proceedings, pages 55-64.
2001-12-14 00:15:06 +00:00
int error, cg, snaploc, numblks;
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
int i, size, len, loc;
Refinement to revision 1.16 of ufs/ffs/ffs_snapshot.c to reduce the amount of time that the filesystem must be suspended. The current snapshot is elided as well as the earlier snapshots.
2001-05-04 05:49:28 +00:00
int flag = mp->mnt_flag;
Minimize the time necessary to suspend operations on a filesystem when taking a snapshot. The two time consuming operations are scanning all the filesystem bitmaps to determine which blocks are in use and scanning all the other snapshots so as to be able to expunge their blocks from the view of the current snapshot. The bitmap scanning is broken into two passes. Before suspending the filesystem all bitmaps are scanned. After the suspension, those bitmaps that changed after being scanned the first time are rescanned. Typically there are few bitmaps that need to be rescanned. The expunging of other snapshots is now done after the suspension is released by observing that we can easily identify any blocks that were allocated to them after the suspension (they will be maked as `not needing to be copied' in the just created snapshot). For all the gory details, see the ``Running fsck in the Background'' paper in the Usenix BSDCon 2002 Conference Proceedings, pages 55-64.
2001-12-14 00:15:06 +00:00
struct timespec starttime = {0, 0}, endtime;
char saved_nice = 0;
long redo = 0;
Refinement to revision 1.16 of ufs/ffs/ffs_snapshot.c to reduce the amount of time that the filesystem must be suspended. The current snapshot is elided as well as the earlier snapshots.
2001-05-04 05:49:28 +00:00
int32_t *lp;
The ffs superblock includes a 128-byte region for use by temporary in-core pointers to summary information. An array in this region (fs_csp) could overflow on filesystems with a very large number of cylinder groups (~16000 on i386 with 8k blocks). When this happens, other fields in the superblock get corrupted, and fsck refuses to check the filesystem. Solve this problem by replacing the fs_csp array in 'struct fs' with a single pointer, and add padding to keep the length of the 128-byte region fixed. Update the kernel and userland utilities to use just this single pointer. With this change, the kernel no longer makes use of the superblock fields 'fs_csshift' and 'fs_csmask'. Add a comment to newfs/mkfs.c to indicate that these fields must be calculated for compatibility with older kernels. Reviewed by: mckusick
2001-01-15 18:30:40 +00:00
void *space;
Refinement to revision 1.16 of ufs/ffs/ffs_snapshot.c to reduce the amount of time that the filesystem must be suspended. The current snapshot is elided as well as the earlier snapshots.
2001-05-04 05:49:28 +00:00
struct fs *copy_fs = NULL, *fs = VFSTOUFS(mp)->um_fs;
Fixes to track snapshot copy-on-write checking in the specinfo structure rather than assuming that the device vnode would reside in the FFS filesystem (which is obviously a broken assumption with the device filesystem).
2001-03-07 07:09:55 +00:00
struct snaphead *snaphead;
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
struct thread *td = curthread;
Fixes to track snapshot copy-on-write checking in the specinfo structure rather than assuming that the device vnode would reside in the FFS filesystem (which is obviously a broken assumption with the device filesystem).
2001-03-07 07:09:55 +00:00
struct inode *ip, *xp;
Refinement to revision 1.16 of ufs/ffs/ffs_snapshot.c to reduce the amount of time that the filesystem must be suspended. The current snapshot is elided as well as the earlier snapshots.
2001-05-04 05:49:28 +00:00
struct buf *bp, *nbp, *ibp, *sbp = NULL;
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
struct nameidata nd;
struct mount *wrtmp;
struct vattr vat;
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
struct vnode *vp, *xvp, *nvp;
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
/*
* Need to serialize access to snapshot code per filesystem.
*/
/*
* Assign a snapshot slot in the superblock.
*/
for (snaploc = 0; snaploc < FSMAXSNAP; snaploc++)
if (fs->fs_snapinum[snaploc] == 0)
break;
if (snaploc == FSMAXSNAP)
return (ENOSPC);
/*
* Create the snapshot file.
*/
restart:
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
NDINIT(&nd, CREATE, LOCKPARENT | LOCKLEAF, UIO_USERSPACE, snapfile, td);
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
if ((error = namei(&nd)) != 0)
return (error);
if (nd.ni_vp != NULL) {
vput(nd.ni_vp);
error = EEXIST;
}
if (nd.ni_dvp->v_mount != mp)
error = EXDEV;
if (error) {
NDFREE(&nd, NDF_ONLY_PNBUF);
if (nd.ni_dvp == nd.ni_vp)
vrele(nd.ni_dvp);
else
vput(nd.ni_dvp);
return (error);
}
VATTR_NULL(&vat);
vat.va_type = VREG;
vat.va_mode = S_IRUSR;
vat.va_vaflags |= VA_EXCLUSIVE;
if (VOP_GETWRITEMOUNT(nd.ni_dvp, &wrtmp))
wrtmp = NULL;
if (wrtmp != mp)
panic("ffs_snapshot: mount mismatch");
Brain fault, forgot to update ffs_snapshot.c with the new calling convention for vn_start_write.
2000-07-12 00:27:27 +00:00
if (vn_start_write(NULL, &wrtmp, V_NOWAIT) != 0) {
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
NDFREE(&nd, NDF_ONLY_PNBUF);
vput(nd.ni_dvp);
Brain fault, forgot to update ffs_snapshot.c with the new calling convention for vn_start_write.
2000-07-12 00:27:27 +00:00
if ((error = vn_start_write(NULL, &wrtmp,
V_XSLEEP | PCATCH)) != 0)
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
return (error);
goto restart;
}
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
VOP_LEASE(nd.ni_dvp, td, KERNCRED, LEASE_WRITE);
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vat);
vput(nd.ni_dvp);
if (error) {
NDFREE(&nd, NDF_ONLY_PNBUF);
vn_finished_write(wrtmp);
return (error);
}
vp = nd.ni_vp;
ip = VTOI(vp);
/*
* Allocate and copy the last block contents so as to be able
* to set size to that of the filesystem.
*/
numblks = howmany(fs->fs_size, fs->fs_frag);
VOP_BALLOC was never really a VOP in the first place, so convert it to UFS_BALLOC like the other "between UFS and FFS function interfaces".
2001-04-29 12:36:52 +00:00
error = UFS_BALLOC(vp, lblktosize(fs, (off_t)(numblks - 1)),
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
fs->fs_bsize, KERNCRED, B_CLRBUF, &bp);
if (error)
goto out;
ip->i_size = lblktosize(fs, (off_t)numblks);
ip->i_flag |= IN_CHANGE | IN_UPDATE;
if ((error = readblock(bp, numblks - 1)) != 0)
goto out;
bawrite(bp);
/*
* Preallocate critical data structures so that we can copy
* them in without further allocation after we suspend all
* operations on the filesystem. We would like to just release
* the allocated buffers without writing them since they will
* be filled in below once we are ready to go, but this upsets
* the soft update code, so we go ahead and write the new buffers.
*
Rather than copying all the indirect blocks of the snapshot, simply mark them as BLK_NOCOPY. This trick cuts the initial size of the snapshot in half and cuts the time to take a snapshot by a third.
2001-04-26 00:50:53 +00:00
* Allocate all indirect blocks and mark all of them as not
* needing to be copied.
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
*/
for (blkno = NDADDR; blkno < numblks; blkno += NINDIR(fs)) {
VOP_BALLOC was never really a VOP in the first place, so convert it to UFS_BALLOC like the other "between UFS and FFS function interfaces".
2001-04-29 12:36:52 +00:00
error = UFS_BALLOC(vp, lblktosize(fs, (off_t)blkno),
Simple p_ucred -> td_ucred changes to start using the per-thread ucred reference.
2002-02-27 18:32:23 +00:00
fs->fs_bsize, td->td_ucred, B_METAONLY, &ibp);
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
if (error)
goto out;
bdwrite(ibp);
}
/*
* Allocate copies for the superblock and its summary information.
*/
Several fixes for units errors: 1) Do not assume that the superblock will be of size fs->fs_bsize. This fixes a panic when taking a snapshot on a filesystem with a block size bigger than 8K. 2) Properly calculate the number of fragments that follow the superblock summary information. This fixes a bug with inconsistent snapshots. 3) When cleaning up a snapshot that is about to be removed, properly calculate the number of blocks that need to be checked. This fixes a bug that created partially allocated inodes. 4) When moving blocks from a snapshot that is about to be removed to another snapshot, properly account for the reduced number of blocks in the snapshot from which they are taken. This fixes a bug in which the number of blocks released from a snapshot did not match the number that it claimed to have.
2001-05-08 07:29:03 +00:00
error = UFS_BALLOC(vp, (off_t)(SBOFF), SBSIZE, KERNCRED, 0, &nbp);
Refinement to revision 1.16 of ufs/ffs/ffs_snapshot.c to reduce the amount of time that the filesystem must be suspended. The current snapshot is elided as well as the earlier snapshots.
2001-05-04 05:49:28 +00:00
if (error)
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
goto out;
bawrite(nbp);
blkno = fragstoblks(fs, fs->fs_csaddr);
len = howmany(fs->fs_cssize, fs->fs_bsize);
for (loc = 0; loc < len; loc++) {
VOP_BALLOC was never really a VOP in the first place, so convert it to UFS_BALLOC like the other "between UFS and FFS function interfaces".
2001-04-29 12:36:52 +00:00
error = UFS_BALLOC(vp, lblktosize(fs, (off_t)(blkno + loc)),
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
fs->fs_bsize, KERNCRED, 0, &nbp);
if (error)
goto out;
bawrite(nbp);
}
Minimize the time necessary to suspend operations on a filesystem when taking a snapshot. The two time consuming operations are scanning all the filesystem bitmaps to determine which blocks are in use and scanning all the other snapshots so as to be able to expunge their blocks from the view of the current snapshot. The bitmap scanning is broken into two passes. Before suspending the filesystem all bitmaps are scanned. After the suspension, those bitmaps that changed after being scanned the first time are rescanned. Typically there are few bitmaps that need to be rescanned. The expunging of other snapshots is now done after the suspension is released by observing that we can easily identify any blocks that were allocated to them after the suspension (they will be maked as `not needing to be copied' in the just created snapshot). For all the gory details, see the ``Running fsck in the Background'' paper in the Usenix BSDCon 2002 Conference Proceedings, pages 55-64.
2001-12-14 00:15:06 +00:00
/*
* Allocate all cylinder group blocks.
*/
for (cg = 0; cg < fs->fs_ncg; cg++) {
error = UFS_BALLOC(vp, (off_t)(cgtod(fs, cg)) << fs->fs_fshift,
fs->fs_bsize, KERNCRED, 0, &nbp);
if (error)
goto out;
bdwrite(nbp);
}
/*
* Copy all the cylinder group maps. Although the
* filesystem is still active, we hope that only a few
* cylinder groups will change between now and when we
* suspend operations. Thus, we will be able to quickly
* touch up the few cylinder groups that changed during
* the suspension period.
*/
Fix a bug introduced in ffs_snapshot.c -r1.25 and fs.h -r1.26 which caused incomplete snapshots to be taken. When background fsck would run on these snapshots, the result would be files being incorrectly released which would subsequently panic the kernel with ``handle_workitem_freefile: inodedep survived'', ``handle_written_inodeblock: live inodedep'', and ``handle_workitem_remove: lost inodedep'' errors.
2002-01-17 08:33:32 +00:00
len = howmany(fs->fs_ncg, NBBY);
Change the atomic_set_char to atomic_set_int and atomic_clear_char to atomic_clear_int to ease the implementation for the sparc64. Requested by: Jake Burkholder <jake@locore.ca>
2001-12-18 18:05:17 +00:00
MALLOC(fs->fs_active, int *, len, M_DEVBUF, M_WAITOK);
Minimize the time necessary to suspend operations on a filesystem when taking a snapshot. The two time consuming operations are scanning all the filesystem bitmaps to determine which blocks are in use and scanning all the other snapshots so as to be able to expunge their blocks from the view of the current snapshot. The bitmap scanning is broken into two passes. Before suspending the filesystem all bitmaps are scanned. After the suspension, those bitmaps that changed after being scanned the first time are rescanned. Typically there are few bitmaps that need to be rescanned. The expunging of other snapshots is now done after the suspension is released by observing that we can easily identify any blocks that were allocated to them after the suspension (they will be maked as `not needing to be copied' in the just created snapshot). For all the gory details, see the ``Running fsck in the Background'' paper in the Usenix BSDCon 2002 Conference Proceedings, pages 55-64.
2001-12-14 00:15:06 +00:00
bzero(fs->fs_active, len);
for (cg = 0; cg < fs->fs_ncg; cg++) {
error = bread(vp, fragstoblks(fs, cgtod(fs, cg)), fs->fs_bsize,
KERNCRED, &nbp);
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
if (error) {
brelse(nbp);
Minimize the time necessary to suspend operations on a filesystem when taking a snapshot. The two time consuming operations are scanning all the filesystem bitmaps to determine which blocks are in use and scanning all the other snapshots so as to be able to expunge their blocks from the view of the current snapshot. The bitmap scanning is broken into two passes. Before suspending the filesystem all bitmaps are scanned. After the suspension, those bitmaps that changed after being scanned the first time are rescanned. Typically there are few bitmaps that need to be rescanned. The expunging of other snapshots is now done after the suspension is released by observing that we can easily identify any blocks that were allocated to them after the suspension (they will be maked as `not needing to be copied' in the just created snapshot). For all the gory details, see the ``Running fsck in the Background'' paper in the Usenix BSDCon 2002 Conference Proceedings, pages 55-64.
2001-12-14 00:15:06 +00:00
goto out;
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
}
Minimize the time necessary to suspend operations on a filesystem when taking a snapshot. The two time consuming operations are scanning all the filesystem bitmaps to determine which blocks are in use and scanning all the other snapshots so as to be able to expunge their blocks from the view of the current snapshot. The bitmap scanning is broken into two passes. Before suspending the filesystem all bitmaps are scanned. After the suspension, those bitmaps that changed after being scanned the first time are rescanned. Typically there are few bitmaps that need to be rescanned. The expunging of other snapshots is now done after the suspension is released by observing that we can easily identify any blocks that were allocated to them after the suspension (they will be maked as `not needing to be copied' in the just created snapshot). For all the gory details, see the ``Running fsck in the Background'' paper in the Usenix BSDCon 2002 Conference Proceedings, pages 55-64.
2001-12-14 00:15:06 +00:00
error = cgaccount(cg, vp, nbp, 1);
bawrite(nbp);
if (error)
goto out;
}
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
/*
* Change inode to snapshot type file.
*/
Clean up the snapshot code so that it no longer depends on the use of the SF_IMMUTABLE flag to prevent writing. Instead put in explicit checking for the SF_SNAPSHOT flag in the appropriate places. With this change, it is now possible to rename and link to snapshot files. It is also possible to set or clear any of the owner, group, or other read bits on the file, though none of the write or execute bits can be set. There is also an explicit test to prevent the setting or clearing of the SF_SNAPSHOT flag via chflags() or fchflags(). Note also that the modify time cannot be changed as it needs to accurately reflect the time that the snapshot was taken. Submitted by: Robert Watson <rwatson@FreeBSD.org>
2000-07-26 23:07:01 +00:00
ip->i_flags |= SF_SNAPSHOT;
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
ip->i_flag |= IN_CHANGE | IN_UPDATE;
/*
* Ensure that the snapshot is completely on disk.
*/
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
if ((error = VOP_FSYNC(vp, KERNCRED, MNT_WAIT, td)) != 0)
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
goto out;
/*
* All allocations are done, so we can now snapshot the system.
*
Minimize the time necessary to suspend operations on a filesystem when taking a snapshot. The two time consuming operations are scanning all the filesystem bitmaps to determine which blocks are in use and scanning all the other snapshots so as to be able to expunge their blocks from the view of the current snapshot. The bitmap scanning is broken into two passes. Before suspending the filesystem all bitmaps are scanned. After the suspension, those bitmaps that changed after being scanned the first time are rescanned. Typically there are few bitmaps that need to be rescanned. The expunging of other snapshots is now done after the suspension is released by observing that we can easily identify any blocks that were allocated to them after the suspension (they will be maked as `not needing to be copied' in the just created snapshot). For all the gory details, see the ``Running fsck in the Background'' paper in the Usenix BSDCon 2002 Conference Proceedings, pages 55-64.
2001-12-14 00:15:06 +00:00
* Recind nice scheduling while running with the filesystem suspended.
*/
if (td->td_ksegrp->kg_nice > 0) {
saved_nice = td->td_ksegrp->kg_nice;
td->td_ksegrp->kg_nice = 0;
}
/*
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
* Suspend operation on filesystem.
*/
for (;;) {
vn_finished_write(wrtmp);
vfs_write_suspend(vp->v_mount);
if (mp->mnt_kern_flag & MNTK_SUSPENDED)
break;
Brain fault, forgot to update ffs_snapshot.c with the new calling convention for vn_start_write.
2000-07-12 00:27:27 +00:00
vn_start_write(NULL, &wrtmp, V_WAIT);
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
}
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
if (collectsnapstats)
nanotime(&starttime);
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
/*
Minimize the time necessary to suspend operations on a filesystem when taking a snapshot. The two time consuming operations are scanning all the filesystem bitmaps to determine which blocks are in use and scanning all the other snapshots so as to be able to expunge their blocks from the view of the current snapshot. The bitmap scanning is broken into two passes. Before suspending the filesystem all bitmaps are scanned. After the suspension, those bitmaps that changed after being scanned the first time are rescanned. Typically there are few bitmaps that need to be rescanned. The expunging of other snapshots is now done after the suspension is released by observing that we can easily identify any blocks that were allocated to them after the suspension (they will be maked as `not needing to be copied' in the just created snapshot). For all the gory details, see the ``Running fsck in the Background'' paper in the Usenix BSDCon 2002 Conference Proceedings, pages 55-64.
2001-12-14 00:15:06 +00:00
* First, copy all the cylinder group maps that have changed.
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
*/
for (cg = 0; cg < fs->fs_ncg; cg++) {
Change the atomic_set_char to atomic_set_int and atomic_clear_char to atomic_clear_int to ease the implementation for the sparc64. Requested by: Jake Burkholder <jake@locore.ca>
2001-12-18 18:05:17 +00:00
if ((ACTIVECGNUM(fs, cg) & ACTIVECGOFF(cg)) != 0)
Minimize the time necessary to suspend operations on a filesystem when taking a snapshot. The two time consuming operations are scanning all the filesystem bitmaps to determine which blocks are in use and scanning all the other snapshots so as to be able to expunge their blocks from the view of the current snapshot. The bitmap scanning is broken into two passes. Before suspending the filesystem all bitmaps are scanned. After the suspension, those bitmaps that changed after being scanned the first time are rescanned. Typically there are few bitmaps that need to be rescanned. The expunging of other snapshots is now done after the suspension is released by observing that we can easily identify any blocks that were allocated to them after the suspension (they will be maked as `not needing to be copied' in the just created snapshot). For all the gory details, see the ``Running fsck in the Background'' paper in the Usenix BSDCon 2002 Conference Proceedings, pages 55-64.
2001-12-14 00:15:06 +00:00
continue;
redo++;
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
error = bread(vp, fragstoblks(fs, cgtod(fs, cg)), fs->fs_bsize,
KERNCRED, &nbp);
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
if (error) {
brelse(nbp);
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
goto out1;
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
}
Minimize the time necessary to suspend operations on a filesystem when taking a snapshot. The two time consuming operations are scanning all the filesystem bitmaps to determine which blocks are in use and scanning all the other snapshots so as to be able to expunge their blocks from the view of the current snapshot. The bitmap scanning is broken into two passes. Before suspending the filesystem all bitmaps are scanned. After the suspension, those bitmaps that changed after being scanned the first time are rescanned. Typically there are few bitmaps that need to be rescanned. The expunging of other snapshots is now done after the suspension is released by observing that we can easily identify any blocks that were allocated to them after the suspension (they will be maked as `not needing to be copied' in the just created snapshot). For all the gory details, see the ``Running fsck in the Background'' paper in the Usenix BSDCon 2002 Conference Proceedings, pages 55-64.
2001-12-14 00:15:06 +00:00
error = cgaccount(cg, vp, nbp, 2);
Fix a bug introduced in ffs_snapshot.c -r1.25 and fs.h -r1.26 which caused incomplete snapshots to be taken. When background fsck would run on these snapshots, the result would be files being incorrectly released which would subsequently panic the kernel with ``handle_workitem_freefile: inodedep survived'', ``handle_written_inodeblock: live inodedep'', and ``handle_workitem_remove: lost inodedep'' errors.
2002-01-17 08:33:32 +00:00
bawrite(nbp);
Minimize the time necessary to suspend operations on a filesystem when taking a snapshot. The two time consuming operations are scanning all the filesystem bitmaps to determine which blocks are in use and scanning all the other snapshots so as to be able to expunge their blocks from the view of the current snapshot. The bitmap scanning is broken into two passes. Before suspending the filesystem all bitmaps are scanned. After the suspension, those bitmaps that changed after being scanned the first time are rescanned. Typically there are few bitmaps that need to be rescanned. The expunging of other snapshots is now done after the suspension is released by observing that we can easily identify any blocks that were allocated to them after the suspension (they will be maked as `not needing to be copied' in the just created snapshot). For all the gory details, see the ``Running fsck in the Background'' paper in the Usenix BSDCon 2002 Conference Proceedings, pages 55-64.
2001-12-14 00:15:06 +00:00
if (error)
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
goto out1;
}
Refinement to revision 1.16 of ufs/ffs/ffs_snapshot.c to reduce the amount of time that the filesystem must be suspended. The current snapshot is elided as well as the earlier snapshots.
2001-05-04 05:49:28 +00:00
/*
* Grab a copy of the superblock and its summary information.
* We delay writing it until the suspension is released below.
*/
error = bread(vp, lblkno(fs, SBOFF), fs->fs_bsize, KERNCRED, &sbp);
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
if (error) {
brelse(sbp);
sbp = NULL;
Refinement to revision 1.16 of ufs/ffs/ffs_snapshot.c to reduce the amount of time that the filesystem must be suspended. The current snapshot is elided as well as the earlier snapshots.
2001-05-04 05:49:28 +00:00
goto out1;
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
}
Refinement to revision 1.16 of ufs/ffs/ffs_snapshot.c to reduce the amount of time that the filesystem must be suspended. The current snapshot is elided as well as the earlier snapshots.
2001-05-04 05:49:28 +00:00
copy_fs = (struct fs *)(sbp->b_data + blkoff(fs, SBOFF));
bcopy(fs, copy_fs, fs->fs_sbsize);
if ((fs->fs_flags & (FS_UNCLEAN | FS_NEEDSFSCK)) == 0)
copy_fs->fs_clean = 1;
if (fs->fs_sbsize < SBSIZE)
bzero(&sbp->b_data[blkoff(fs, SBOFF) + fs->fs_sbsize],
SBSIZE - fs->fs_sbsize);
size = blkroundup(fs, fs->fs_cssize);
if (fs->fs_contigsumsize > 0)
size += fs->fs_ncg * sizeof(int32_t);
space = malloc((u_long)size, M_UFSMNT, M_WAITOK);
copy_fs->fs_csp = space;
bcopy(fs->fs_csp, copy_fs->fs_csp, fs->fs_cssize);
(char *)space += fs->fs_cssize;
loc = howmany(fs->fs_cssize, fs->fs_fsize);
Several fixes for units errors: 1) Do not assume that the superblock will be of size fs->fs_bsize. This fixes a panic when taking a snapshot on a filesystem with a block size bigger than 8K. 2) Properly calculate the number of fragments that follow the superblock summary information. This fixes a bug with inconsistent snapshots. 3) When cleaning up a snapshot that is about to be removed, properly calculate the number of blocks that need to be checked. This fixes a bug that created partially allocated inodes. 4) When moving blocks from a snapshot that is about to be removed to another snapshot, properly account for the reduced number of blocks in the snapshot from which they are taken. This fixes a bug in which the number of blocks released from a snapshot did not match the number that it claimed to have.
2001-05-08 07:29:03 +00:00
i = fs->fs_frag - loc % fs->fs_frag;
len = (i == fs->fs_frag) ? 0 : i * fs->fs_fsize;
if (len > 0) {
Refinement to revision 1.16 of ufs/ffs/ffs_snapshot.c to reduce the amount of time that the filesystem must be suspended. The current snapshot is elided as well as the earlier snapshots.
2001-05-04 05:49:28 +00:00
if ((error = bread(ip->i_devvp,
fsbtodb(fs, fs->fs_csaddr + loc),
len, KERNCRED, &bp)) != 0) {
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
brelse(bp);
Refinement to revision 1.16 of ufs/ffs/ffs_snapshot.c to reduce the amount of time that the filesystem must be suspended. The current snapshot is elided as well as the earlier snapshots.
2001-05-04 05:49:28 +00:00
free(copy_fs->fs_csp, M_UFSMNT);
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
bawrite(sbp);
sbp = NULL;
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
goto out1;
Refinement to revision 1.16 of ufs/ffs/ffs_snapshot.c to reduce the amount of time that the filesystem must be suspended. The current snapshot is elided as well as the earlier snapshots.
2001-05-04 05:49:28 +00:00
}
bcopy(bp->b_data, space, (u_int)len);
(char *)space += len;
bp->b_flags |= B_INVAL | B_NOCACHE;
brelse(bp);
}
if (fs->fs_contigsumsize > 0) {
copy_fs->fs_maxcluster = lp = space;
for (i = 0; i < fs->fs_ncg; i++)
*lp++ = fs->fs_contigsumsize;
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
}
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
/*
* We must check for active files that have been unlinked
* (e.g., with a zero link count). We have to expunge all
* trace of these files from the snapshot so that they are
* not reclaimed prematurely by fsck or unnecessarily dumped.
* We turn off the MNTK_SUSPENDED flag to avoid a panic from
* spec_strategy about writing on a suspended filesystem.
*/
mp->mnt_kern_flag &= ~MNTK_SUSPENDED;
mtx_lock(&mntvnode_mtx);
loop:
for (xvp = TAILQ_FIRST(&mp->mnt_nvnodelist); xvp; xvp = nvp) {
/*
* Make sure this vnode wasn't reclaimed in getnewvnode().
* Start over if it has (it won't be on the list anymore).
*/
if (xvp->v_mount != mp)
goto loop;
nvp = TAILQ_NEXT(xvp, v_nmntvnodes);
mtx_unlock(&mntvnode_mtx);
mtx_lock(&xvp->v_interlock);
if (xvp->v_usecount == 0 || xvp->v_type == VNON ||
(VOP_GETATTR(xvp, &vat, td->td_proc->p_ucred, td) == 0 &&
vat.va_nlink > 0)) {
mtx_unlock(&xvp->v_interlock);
mtx_lock(&mntvnode_mtx);
continue;
}
if (snapdebug)
vprint("ffs_snapshot: busy vnode", xvp);
if (vn_lock(xvp, LK_EXCLUSIVE | LK_INTERLOCK, td) != 0)
goto loop;
xp = VTOI(xvp);
/*
* If there is a fragment, clear it here.
*/
blkno = 0;
loc = howmany(xp->i_size, fs->fs_bsize) - 1;
if (loc < NDADDR) {
len = fragroundup(fs, blkoff(fs, xp->i_size));
if (len < fs->fs_bsize) {
ffs_blkfree(copy_fs, vp, xp->i_db[loc], len,
xp->i_number);
blkno = xp->i_db[loc];
xp->i_db[loc] = 0;
}
}
error = expunge(vp, xp, copy_fs, fullacct, BLK_NOCOPY);
if (blkno)
xp->i_db[loc] = blkno;
if (!error)
error = ffs_freefile(copy_fs, vp, xp->i_number,
xp->i_mode);
VOP_UNLOCK(xvp, 0, td);
if (error) {
free(copy_fs->fs_csp, M_UFSMNT);
bawrite(sbp);
sbp = NULL;
goto out1;
}
mtx_lock(&mntvnode_mtx);
}
mtx_unlock(&mntvnode_mtx);
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
/*
* Record snapshot inode. Since this is the newest snapshot,
* it must be placed at the end of the list.
*/
fs->fs_snapinum[snaploc] = ip->i_number;
Fixes to track snapshot copy-on-write checking in the specinfo structure rather than assuming that the device vnode would reside in the FFS filesystem (which is obviously a broken assumption with the device filesystem).
2001-03-07 07:09:55 +00:00
if (ip->i_nextsnap.tqe_prev != 0)
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
panic("ffs_snapshot: %d already on list", ip->i_number);
Minimize the time necessary to suspend operations on a filesystem when taking a snapshot. The two time consuming operations are scanning all the filesystem bitmaps to determine which blocks are in use and scanning all the other snapshots so as to be able to expunge their blocks from the view of the current snapshot. The bitmap scanning is broken into two passes. Before suspending the filesystem all bitmaps are scanned. After the suspension, those bitmaps that changed after being scanned the first time are rescanned. Typically there are few bitmaps that need to be rescanned. The expunging of other snapshots is now done after the suspension is released by observing that we can easily identify any blocks that were allocated to them after the suspension (they will be maked as `not needing to be copied' in the just created snapshot). For all the gory details, see the ``Running fsck in the Background'' paper in the Usenix BSDCon 2002 Conference Proceedings, pages 55-64.
2001-12-14 00:15:06 +00:00
snaphead = &ip->i_devvp->v_rdev->si_snapshots;
Fixes to track snapshot copy-on-write checking in the specinfo structure rather than assuming that the device vnode would reside in the FFS filesystem (which is obviously a broken assumption with the device filesystem).
2001-03-07 07:09:55 +00:00
TAILQ_INSERT_TAIL(snaphead, ip, i_nextsnap);
ip->i_devvp->v_rdev->si_copyonwrite = ffs_copyonwrite;
ip->i_devvp->v_flag |= VCOPYONWRITE;
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
vp->v_flag |= VSYSTEM;
Minimize the time necessary to suspend operations on a filesystem when taking a snapshot. The two time consuming operations are scanning all the filesystem bitmaps to determine which blocks are in use and scanning all the other snapshots so as to be able to expunge their blocks from the view of the current snapshot. The bitmap scanning is broken into two passes. Before suspending the filesystem all bitmaps are scanned. After the suspension, those bitmaps that changed after being scanned the first time are rescanned. Typically there are few bitmaps that need to be rescanned. The expunging of other snapshots is now done after the suspension is released by observing that we can easily identify any blocks that were allocated to them after the suspension (they will be maked as `not needing to be copied' in the just created snapshot). For all the gory details, see the ``Running fsck in the Background'' paper in the Usenix BSDCon 2002 Conference Proceedings, pages 55-64.
2001-12-14 00:15:06 +00:00
out1:
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
/*
* Resume operation on filesystem.
*/
vfs_write_resume(vp->v_mount);
Minimize the time necessary to suspend operations on a filesystem when taking a snapshot. The two time consuming operations are scanning all the filesystem bitmaps to determine which blocks are in use and scanning all the other snapshots so as to be able to expunge their blocks from the view of the current snapshot. The bitmap scanning is broken into two passes. Before suspending the filesystem all bitmaps are scanned. After the suspension, those bitmaps that changed after being scanned the first time are rescanned. Typically there are few bitmaps that need to be rescanned. The expunging of other snapshots is now done after the suspension is released by observing that we can easily identify any blocks that were allocated to them after the suspension (they will be maked as `not needing to be copied' in the just created snapshot). For all the gory details, see the ``Running fsck in the Background'' paper in the Usenix BSDCon 2002 Conference Proceedings, pages 55-64.
2001-12-14 00:15:06 +00:00
if (saved_nice > 0)
td->td_ksegrp->kg_nice = saved_nice;
Brain fault, forgot to update ffs_snapshot.c with the new calling convention for vn_start_write.
2000-07-12 00:27:27 +00:00
vn_start_write(NULL, &wrtmp, V_WAIT);
Minimize the time necessary to suspend operations on a filesystem when taking a snapshot. The two time consuming operations are scanning all the filesystem bitmaps to determine which blocks are in use and scanning all the other snapshots so as to be able to expunge their blocks from the view of the current snapshot. The bitmap scanning is broken into two passes. Before suspending the filesystem all bitmaps are scanned. After the suspension, those bitmaps that changed after being scanned the first time are rescanned. Typically there are few bitmaps that need to be rescanned. The expunging of other snapshots is now done after the suspension is released by observing that we can easily identify any blocks that were allocated to them after the suspension (they will be maked as `not needing to be copied' in the just created snapshot). For all the gory details, see the ``Running fsck in the Background'' paper in the Usenix BSDCon 2002 Conference Proceedings, pages 55-64.
2001-12-14 00:15:06 +00:00
if (collectsnapstats && starttime.tv_sec > 0) {
nanotime(&endtime);
timespecsub(&endtime, &starttime);
printf("%s: suspended %d.%03ld sec, redo %ld of %d\n",
vp->v_mount->mnt_stat.f_mntonname, endtime.tv_sec,
endtime.tv_nsec / 1000000, redo, fs->fs_ncg);
}
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
if (sbp == NULL)
goto out;
/*
* Copy allocation information from all the snapshots in
* this snapshot and then expunge them from its view.
*/
snaphead = &ip->i_devvp->v_rdev->si_snapshots;
TAILQ_FOREACH(xp, snaphead, i_nextsnap) {
if (xp == ip)
break;
if ((error = expunge(vp, xp, fs, snapacct, BLK_SNAP)) != 0) {
fs->fs_snapinum[snaploc] = 0;
goto done;
Refinement to revision 1.16 of ufs/ffs/ffs_snapshot.c to reduce the amount of time that the filesystem must be suspended. The current snapshot is elided as well as the earlier snapshots.
2001-05-04 05:49:28 +00:00
}
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
}
/*
* Expunge the blocks used by the snapshots from the set of
* blocks marked as used in the snapshot bitmaps.
*/
if ((error = expunge(vp, ip, copy_fs, mapacct, BLK_SNAP)) != 0) {
fs->fs_snapinum[snaploc] = 0;
goto done;
}
/*
* Write the superblock and its summary information
* to the snapshot.
*/
blkno = fragstoblks(fs, fs->fs_csaddr);
len = howmany(fs->fs_cssize, fs->fs_bsize);
space = copy_fs->fs_csp;
for (loc = 0; loc < len; loc++) {
error = bread(vp, blkno + loc, fs->fs_bsize, KERNCRED, &nbp);
if (error) {
brelse(nbp);
fs->fs_snapinum[snaploc] = 0;
goto done;
Refinement to revision 1.16 of ufs/ffs/ffs_snapshot.c to reduce the amount of time that the filesystem must be suspended. The current snapshot is elided as well as the earlier snapshots.
2001-05-04 05:49:28 +00:00
}
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
bcopy(space, nbp->b_data, fs->fs_bsize);
space = (char *)space + fs->fs_bsize;
bawrite(nbp);
Refinement to revision 1.16 of ufs/ffs/ffs_snapshot.c to reduce the amount of time that the filesystem must be suspended. The current snapshot is elided as well as the earlier snapshots.
2001-05-04 05:49:28 +00:00
}
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
done:
free(copy_fs->fs_csp, M_UFSMNT);
bawrite(sbp);
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
out:
Minimize the time necessary to suspend operations on a filesystem when taking a snapshot. The two time consuming operations are scanning all the filesystem bitmaps to determine which blocks are in use and scanning all the other snapshots so as to be able to expunge their blocks from the view of the current snapshot. The bitmap scanning is broken into two passes. Before suspending the filesystem all bitmaps are scanned. After the suspension, those bitmaps that changed after being scanned the first time are rescanned. Typically there are few bitmaps that need to be rescanned. The expunging of other snapshots is now done after the suspension is released by observing that we can easily identify any blocks that were allocated to them after the suspension (they will be maked as `not needing to be copied' in the just created snapshot). For all the gory details, see the ``Running fsck in the Background'' paper in the Usenix BSDCon 2002 Conference Proceedings, pages 55-64.
2001-12-14 00:15:06 +00:00
if (fs->fs_active != 0) {
FREE(fs->fs_active, M_DEVBUF);
fs->fs_active = 0;
}
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
mp->mnt_flag = flag;
Refinement to revision 1.16 of ufs/ffs/ffs_snapshot.c to reduce the amount of time that the filesystem must be suspended. The current snapshot is elided as well as the earlier snapshots.
2001-05-04 05:49:28 +00:00
if (error)
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
(void) UFS_TRUNCATE(vp, (off_t)0, 0, NOCRED, td);
(void) VOP_FSYNC(vp, KERNCRED, MNT_WAIT, td);
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
if (error)
vput(vp);
else
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
VOP_UNLOCK(vp, 0, td);
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
vn_finished_write(wrtmp);
return (error);
}
Minimize the time necessary to suspend operations on a filesystem when taking a snapshot. The two time consuming operations are scanning all the filesystem bitmaps to determine which blocks are in use and scanning all the other snapshots so as to be able to expunge their blocks from the view of the current snapshot. The bitmap scanning is broken into two passes. Before suspending the filesystem all bitmaps are scanned. After the suspension, those bitmaps that changed after being scanned the first time are rescanned. Typically there are few bitmaps that need to be rescanned. The expunging of other snapshots is now done after the suspension is released by observing that we can easily identify any blocks that were allocated to them after the suspension (they will be maked as `not needing to be copied' in the just created snapshot). For all the gory details, see the ``Running fsck in the Background'' paper in the Usenix BSDCon 2002 Conference Proceedings, pages 55-64.
2001-12-14 00:15:06 +00:00
/*
* Copy a cylinder group map. All the unallocated blocks are marked
* BLK_NOCOPY so that the snapshot knows that it need not copy them
Introduce the new 64-bit size disk block, daddr64_t. Change the bio and buffer structures to have daddr64_t bio_pblkno, b_blkno, and b_lblkno fields which allows access to disks larger than a Terabyte in size. This change also requires that the VOP_BMAP vnode operation accept and return daddr64_t blocks. This delta should not affect system operation in any way. It merely sets up the necessary interfaces to allow the development of disk drivers that work with these larger disk block addresses. It also allows for the development of UFS2 which will use 64-bit block addresses.
2002-03-15 18:49:47 +00:00
* if they are later written. If passno is one, then this is a first
* pass, so only setting needs to be done. If passno is 2, then this
Minimize the time necessary to suspend operations on a filesystem when taking a snapshot. The two time consuming operations are scanning all the filesystem bitmaps to determine which blocks are in use and scanning all the other snapshots so as to be able to expunge their blocks from the view of the current snapshot. The bitmap scanning is broken into two passes. Before suspending the filesystem all bitmaps are scanned. After the suspension, those bitmaps that changed after being scanned the first time are rescanned. Typically there are few bitmaps that need to be rescanned. The expunging of other snapshots is now done after the suspension is released by observing that we can easily identify any blocks that were allocated to them after the suspension (they will be maked as `not needing to be copied' in the just created snapshot). For all the gory details, see the ``Running fsck in the Background'' paper in the Usenix BSDCon 2002 Conference Proceedings, pages 55-64.
2001-12-14 00:15:06 +00:00
* is a revision to a previous pass which must be undone as the
* replacement pass is done.
*/
static int
cgaccount(cg, vp, nbp, passno)
int cg;
struct vnode *vp;
struct buf *nbp;
int passno;
{
struct buf *bp, *ibp;
struct inode *ip;
struct cg *cgp;
struct fs *fs;
int error, numblks, base, len, loc, indiroff;
ip = VTOI(vp);
fs = ip->i_fs;
error = bread(ip->i_devvp, fsbtodb(fs, cgtod(fs, cg)),
(int)fs->fs_cgsize, KERNCRED, &bp);
if (error) {
brelse(bp);
return (error);
}
cgp = (struct cg *)bp->b_data;
if (!cg_chkmagic(cgp)) {
brelse(bp);
return (EIO);
}
Change the atomic_set_char to atomic_set_int and atomic_clear_char to atomic_clear_int to ease the implementation for the sparc64. Requested by: Jake Burkholder <jake@locore.ca>
2001-12-18 18:05:17 +00:00
atomic_set_int(&ACTIVECGNUM(fs, cg), ACTIVECGOFF(cg));
Minimize the time necessary to suspend operations on a filesystem when taking a snapshot. The two time consuming operations are scanning all the filesystem bitmaps to determine which blocks are in use and scanning all the other snapshots so as to be able to expunge their blocks from the view of the current snapshot. The bitmap scanning is broken into two passes. Before suspending the filesystem all bitmaps are scanned. After the suspension, those bitmaps that changed after being scanned the first time are rescanned. Typically there are few bitmaps that need to be rescanned. The expunging of other snapshots is now done after the suspension is released by observing that we can easily identify any blocks that were allocated to them after the suspension (they will be maked as `not needing to be copied' in the just created snapshot). For all the gory details, see the ``Running fsck in the Background'' paper in the Usenix BSDCon 2002 Conference Proceedings, pages 55-64.
2001-12-14 00:15:06 +00:00
bcopy(bp->b_data, nbp->b_data, fs->fs_cgsize);
if (fs->fs_cgsize < fs->fs_bsize)
bzero(&nbp->b_data[fs->fs_cgsize],
fs->fs_bsize - fs->fs_cgsize);
if (passno == 2)
nbp->b_flags |= B_VALIDSUSPWRT;
numblks = howmany(fs->fs_size, fs->fs_frag);
len = howmany(fs->fs_fpg, fs->fs_frag);
base = cg * fs->fs_fpg / fs->fs_frag;
if (base + len >= numblks)
len = numblks - base - 1;
loc = 0;
if (base < NDADDR) {
for ( ; loc < NDADDR; loc++) {
if (ffs_isblock(fs, cg_blksfree(cgp), loc))
ip->i_db[loc] = BLK_NOCOPY;
else if (passno == 2 && ip->i_db[loc] == BLK_NOCOPY)
ip->i_db[loc] = 0;
else if (passno == 1 && ip->i_db[loc] == BLK_NOCOPY)
panic("ffs_snapshot: lost direct block");
}
}
error = UFS_BALLOC(vp, lblktosize(fs, (off_t)(base + loc)),
fs->fs_bsize, KERNCRED, B_METAONLY, &ibp);
if (error) {
brelse(bp);
return (error);
}
indiroff = (base + loc - NDADDR) % NINDIR(fs);
for ( ; loc < len; loc++, indiroff++) {
if (indiroff >= NINDIR(fs)) {
if (passno == 2)
ibp->b_flags |= B_VALIDSUSPWRT;
bawrite(ibp);
error = UFS_BALLOC(vp,
lblktosize(fs, (off_t)(base + loc)),
fs->fs_bsize, KERNCRED, B_METAONLY, &ibp);
if (error) {
brelse(bp);
return (error);
}
indiroff = 0;
}
if (ffs_isblock(fs, cg_blksfree(cgp), loc))
((ufs_daddr_t *)(ibp->b_data))[indiroff] = BLK_NOCOPY;
else if (passno == 2 &&
((ufs_daddr_t *)(ibp->b_data))[indiroff] == BLK_NOCOPY)
((ufs_daddr_t *)(ibp->b_data))[indiroff] = 0;
else if (passno == 1 &&
((ufs_daddr_t *)(ibp->b_data))[indiroff] == BLK_NOCOPY)
panic("ffs_snapshot: lost indirect block");
}
bqrelse(bp);
if (passno == 2)
ibp->b_flags |= B_VALIDSUSPWRT;
bdwrite(ibp);
return (0);
}
Refinement to revision 1.16 of ufs/ffs/ffs_snapshot.c to reduce the amount of time that the filesystem must be suspended. The current snapshot is elided as well as the earlier snapshots.
2001-05-04 05:49:28 +00:00
/*
* Before expunging a snapshot inode, note all the
* blocks that it claims with BLK_SNAP so that fsck will
* be able to account for those blocks properly and so
* that this snapshot knows that it need not copy them
* if the other snapshot holding them is freed.
*/
static int
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
expunge(snapvp, cancelip, fs, acctfunc, expungetype)
struct vnode *snapvp;
struct inode *cancelip;
Refinement to revision 1.16 of ufs/ffs/ffs_snapshot.c to reduce the amount of time that the filesystem must be suspended. The current snapshot is elided as well as the earlier snapshots.
2001-05-04 05:49:28 +00:00
struct fs *fs;
Remove __P.
2002-03-19 22:40:48 +00:00
int (*acctfunc)(struct vnode *, ufs_daddr_t *, ufs_daddr_t *,
struct fs *, ufs_daddr_t, int);
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
int expungetype;
Refinement to revision 1.16 of ufs/ffs/ffs_snapshot.c to reduce the amount of time that the filesystem must be suspended. The current snapshot is elided as well as the earlier snapshots.
2001-05-04 05:49:28 +00:00
{
int i, len, error, numblks, blksperindir;
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
ufs_daddr_t lbn, rlbn, blkno, indiroff;
struct thread *td = curthread;
Refinement to revision 1.16 of ufs/ffs/ffs_snapshot.c to reduce the amount of time that the filesystem must be suspended. The current snapshot is elided as well as the earlier snapshots.
2001-05-04 05:49:28 +00:00
struct dinode *dip;
struct buf *bp;
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
numblks = howmany(cancelip->i_size, fs->fs_bsize);
if ((error = (*acctfunc)(snapvp, &cancelip->i_db[0],
&cancelip->i_ib[NIADDR], fs, 0, expungetype)))
Refinement to revision 1.16 of ufs/ffs/ffs_snapshot.c to reduce the amount of time that the filesystem must be suspended. The current snapshot is elided as well as the earlier snapshots.
2001-05-04 05:49:28 +00:00
return (error);
blksperindir = 1;
lbn = -NDADDR;
len = numblks - NDADDR;
rlbn = NDADDR;
for (i = 0; len > 0 && i < NIADDR; i++) {
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
error = indiracct(snapvp, ITOV(cancelip), i, cancelip->i_ib[i],
lbn, rlbn, len, blksperindir, fs, acctfunc, expungetype);
Refinement to revision 1.16 of ufs/ffs/ffs_snapshot.c to reduce the amount of time that the filesystem must be suspended. The current snapshot is elided as well as the earlier snapshots.
2001-05-04 05:49:28 +00:00
if (error)
return (error);
blksperindir *= NINDIR(fs);
lbn -= blksperindir + 1;
len -= blksperindir;
rlbn += blksperindir;
}
/*
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
* Prepare to expunge the inode. If its inode block has not
* yet been copied, then allocate and fill the copy.
Refinement to revision 1.16 of ufs/ffs/ffs_snapshot.c to reduce the amount of time that the filesystem must be suspended. The current snapshot is elided as well as the earlier snapshots.
2001-05-04 05:49:28 +00:00
*/
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
lbn = fragstoblks(fs, ino_to_fsba(fs, cancelip->i_number));
blkno = 0;
if (lbn < NDADDR) {
blkno = cancelip->i_db[lbn];
} else {
td->td_proc->p_flag |= P_COWINPROGRESS;
error = UFS_BALLOC(snapvp, lblktosize(fs, (off_t)lbn),
fs->fs_bsize, KERNCRED, B_METAONLY, &bp);
td->td_proc->p_flag &= ~P_COWINPROGRESS;
if (error)
return (error);
indiroff = (lbn - NDADDR) % NINDIR(fs);
blkno = ((ufs_daddr_t *)(bp->b_data))[indiroff];
bqrelse(bp);
}
error = UFS_BALLOC(snapvp, lblktosize(fs, (off_t)lbn),
fs->fs_bsize, KERNCRED, 0, &bp);
if (error)
return (error);
if (blkno == 0 && (error = readblock(bp, lbn)))
Refinement to revision 1.16 of ufs/ffs/ffs_snapshot.c to reduce the amount of time that the filesystem must be suspended. The current snapshot is elided as well as the earlier snapshots.
2001-05-04 05:49:28 +00:00
return (error);
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
/*
* Set a snapshot inode to be a zero length file, regular files
* to be completely unallocated.
*/
dip = (struct dinode *)bp->b_data + ino_to_fsbo(fs, cancelip->i_number);
if (expungetype == BLK_NOCOPY)
dip->di_mode = 0;
Refinement to revision 1.16 of ufs/ffs/ffs_snapshot.c to reduce the amount of time that the filesystem must be suspended. The current snapshot is elided as well as the earlier snapshots.
2001-05-04 05:49:28 +00:00
dip->di_size = 0;
dip->di_blocks = 0;
dip->di_flags &= ~SF_SNAPSHOT;
bzero(&dip->di_db[0], (NDADDR + NIADDR) * sizeof(ufs_daddr_t));
bdwrite(bp);
return (0);
}
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
/*
* Descend an indirect block chain for vnode cancelvp accounting for all
* its indirect blocks in snapvp.
*/
static int
Refinement to revision 1.16 of ufs/ffs/ffs_snapshot.c to reduce the amount of time that the filesystem must be suspended. The current snapshot is elided as well as the earlier snapshots.
2001-05-04 05:49:28 +00:00
indiracct(snapvp, cancelvp, level, blkno, lbn, rlbn, remblks, blksperindir, fs,
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
acctfunc, expungetype)
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
struct vnode *snapvp;
struct vnode *cancelvp;
int level;
ufs_daddr_t blkno;
int lbn;
int rlbn;
int remblks;
int blksperindir;
Refinement to revision 1.16 of ufs/ffs/ffs_snapshot.c to reduce the amount of time that the filesystem must be suspended. The current snapshot is elided as well as the earlier snapshots.
2001-05-04 05:49:28 +00:00
struct fs *fs;
Remove __P.
2002-03-19 22:40:48 +00:00
int (*acctfunc)(struct vnode *, ufs_daddr_t *, ufs_daddr_t *,
struct fs *, ufs_daddr_t, int);
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
int expungetype;
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
{
int subblksperindir, error, last, num, i;
struct indir indirs[NIADDR + 2];
ufs_daddr_t *bap;
struct buf *bp;
if ((error = ufs_getlbns(cancelvp, rlbn, indirs, &num)) != 0)
return (error);
if (lbn != indirs[num - 1 - level].in_lbn || blkno == 0 || num < 2)
panic("indiracct: botched params");
/*
* We have to expand bread here since it will deadlock looking
* up the block number for any blocks that are not in the cache.
*/
bp = getblk(cancelvp, lbn, fs->fs_bsize, 0, 0);
bp->b_blkno = fsbtodb(fs, blkno);
if ((bp->b_flags & (B_DONE | B_DELWRI)) == 0 &&
(error = readblock(bp, fragstoblks(fs, blkno)))) {
brelse(bp);
return (error);
}
/*
* Account for the block pointers in this indirect block.
*/
last = howmany(remblks, blksperindir);
if (last > NINDIR(fs))
last = NINDIR(fs);
Refinement to revision 1.16 of ufs/ffs/ffs_snapshot.c to reduce the amount of time that the filesystem must be suspended. The current snapshot is elided as well as the earlier snapshots.
2001-05-04 05:49:28 +00:00
MALLOC(bap, ufs_daddr_t *, fs->fs_bsize, M_DEVBUF, M_WAITOK);
bcopy(bp->b_data, (caddr_t)bap, fs->fs_bsize);
bqrelse(bp);
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
error = (*acctfunc)(snapvp, &bap[0], &bap[last], fs, rlbn, expungetype);
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
if (error || level == 0)
goto out;
/*
* Account for the block pointers in each of the indirect blocks
* in the levels below us.
*/
subblksperindir = blksperindir / NINDIR(fs);
for (lbn++, level--, i = 0; i < last; i++) {
error = indiracct(snapvp, cancelvp, level, bap[i], lbn,
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
rlbn, remblks, subblksperindir, fs, acctfunc, expungetype);
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
if (error)
goto out;
rlbn += blksperindir;
lbn -= blksperindir;
remblks -= blksperindir;
}
out:
Refinement to revision 1.16 of ufs/ffs/ffs_snapshot.c to reduce the amount of time that the filesystem must be suspended. The current snapshot is elided as well as the earlier snapshots.
2001-05-04 05:49:28 +00:00
FREE(bap, M_DEVBUF);
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
return (error);
}
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
/*
* Do both snap accounting and map accounting.
*/
static int
fullacct(vp, oldblkp, lastblkp, fs, lblkno, expungetype)
struct vnode *vp;
ufs_daddr_t *oldblkp, *lastblkp;
struct fs *fs;
ufs_daddr_t lblkno;
int expungetype; /* BLK_SNAP or BLK_NOCOPY */
{
int error;
if ((error = snapacct(vp, oldblkp, lastblkp, fs, lblkno, expungetype)))
return (error);
return (mapacct(vp, oldblkp, lastblkp, fs, lblkno, expungetype));
}
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
/*
Minimize the time necessary to suspend operations on a filesystem when taking a snapshot. The two time consuming operations are scanning all the filesystem bitmaps to determine which blocks are in use and scanning all the other snapshots so as to be able to expunge their blocks from the view of the current snapshot. The bitmap scanning is broken into two passes. Before suspending the filesystem all bitmaps are scanned. After the suspension, those bitmaps that changed after being scanned the first time are rescanned. Typically there are few bitmaps that need to be rescanned. The expunging of other snapshots is now done after the suspension is released by observing that we can easily identify any blocks that were allocated to them after the suspension (they will be maked as `not needing to be copied' in the just created snapshot). For all the gory details, see the ``Running fsck in the Background'' paper in the Usenix BSDCon 2002 Conference Proceedings, pages 55-64.
2001-12-14 00:15:06 +00:00
* Identify a set of blocks allocated in a snapshot inode.
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
*/
static int
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
snapacct(vp, oldblkp, lastblkp, fs, lblkno, expungetype)
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
struct vnode *vp;
ufs_daddr_t *oldblkp, *lastblkp;
Refinement to revision 1.16 of ufs/ffs/ffs_snapshot.c to reduce the amount of time that the filesystem must be suspended. The current snapshot is elided as well as the earlier snapshots.
2001-05-04 05:49:28 +00:00
struct fs *fs;
ufs_daddr_t lblkno;
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
int expungetype; /* BLK_SNAP or BLK_NOCOPY */
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
{
struct inode *ip = VTOI(vp);
ufs_daddr_t lbn, blkno, *blkp;
struct buf *ibp;
int error;
for ( ; oldblkp < lastblkp; oldblkp++) {
blkno = *oldblkp;
if (blkno == 0 || blkno == BLK_NOCOPY || blkno == BLK_SNAP)
continue;
lbn = fragstoblks(fs, blkno);
if (lbn < NDADDR) {
blkp = &ip->i_db[lbn];
ip->i_flag |= IN_CHANGE | IN_UPDATE;
} else {
VOP_BALLOC was never really a VOP in the first place, so convert it to UFS_BALLOC like the other "between UFS and FFS function interfaces".
2001-04-29 12:36:52 +00:00
error = UFS_BALLOC(vp, lblktosize(fs, (off_t)lbn),
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
fs->fs_bsize, KERNCRED, B_METAONLY, &ibp);
if (error)
return (error);
blkp = &((ufs_daddr_t *)(ibp->b_data))
[(lbn - NDADDR) % NINDIR(fs)];
}
Minimize the time necessary to suspend operations on a filesystem when taking a snapshot. The two time consuming operations are scanning all the filesystem bitmaps to determine which blocks are in use and scanning all the other snapshots so as to be able to expunge their blocks from the view of the current snapshot. The bitmap scanning is broken into two passes. Before suspending the filesystem all bitmaps are scanned. After the suspension, those bitmaps that changed after being scanned the first time are rescanned. Typically there are few bitmaps that need to be rescanned. The expunging of other snapshots is now done after the suspension is released by observing that we can easily identify any blocks that were allocated to them after the suspension (they will be maked as `not needing to be copied' in the just created snapshot). For all the gory details, see the ``Running fsck in the Background'' paper in the Usenix BSDCon 2002 Conference Proceedings, pages 55-64.
2001-12-14 00:15:06 +00:00
/*
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
* If we are expunging a snapshot vnode and we
* find a block marked BLK_NOCOPY, then it is
Minimize the time necessary to suspend operations on a filesystem when taking a snapshot. The two time consuming operations are scanning all the filesystem bitmaps to determine which blocks are in use and scanning all the other snapshots so as to be able to expunge their blocks from the view of the current snapshot. The bitmap scanning is broken into two passes. Before suspending the filesystem all bitmaps are scanned. After the suspension, those bitmaps that changed after being scanned the first time are rescanned. Typically there are few bitmaps that need to be rescanned. The expunging of other snapshots is now done after the suspension is released by observing that we can easily identify any blocks that were allocated to them after the suspension (they will be maked as `not needing to be copied' in the just created snapshot). For all the gory details, see the ``Running fsck in the Background'' paper in the Usenix BSDCon 2002 Conference Proceedings, pages 55-64.
2001-12-14 00:15:06 +00:00
* one that has been allocated to this snapshot after
* we took our current snapshot and can be ignored.
*/
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
if (expungetype == BLK_SNAP && *blkp == BLK_NOCOPY) {
Minimize the time necessary to suspend operations on a filesystem when taking a snapshot. The two time consuming operations are scanning all the filesystem bitmaps to determine which blocks are in use and scanning all the other snapshots so as to be able to expunge their blocks from the view of the current snapshot. The bitmap scanning is broken into two passes. Before suspending the filesystem all bitmaps are scanned. After the suspension, those bitmaps that changed after being scanned the first time are rescanned. Typically there are few bitmaps that need to be rescanned. The expunging of other snapshots is now done after the suspension is released by observing that we can easily identify any blocks that were allocated to them after the suspension (they will be maked as `not needing to be copied' in the just created snapshot). For all the gory details, see the ``Running fsck in the Background'' paper in the Usenix BSDCon 2002 Conference Proceedings, pages 55-64.
2001-12-14 00:15:06 +00:00
if (lbn >= NDADDR)
brelse(ibp);
} else {
if (*blkp != 0)
panic("snapacct: bad block");
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
*blkp = expungetype;
Minimize the time necessary to suspend operations on a filesystem when taking a snapshot. The two time consuming operations are scanning all the filesystem bitmaps to determine which blocks are in use and scanning all the other snapshots so as to be able to expunge their blocks from the view of the current snapshot. The bitmap scanning is broken into two passes. Before suspending the filesystem all bitmaps are scanned. After the suspension, those bitmaps that changed after being scanned the first time are rescanned. Typically there are few bitmaps that need to be rescanned. The expunging of other snapshots is now done after the suspension is released by observing that we can easily identify any blocks that were allocated to them after the suspension (they will be maked as `not needing to be copied' in the just created snapshot). For all the gory details, see the ``Running fsck in the Background'' paper in the Usenix BSDCon 2002 Conference Proceedings, pages 55-64.
2001-12-14 00:15:06 +00:00
if (lbn >= NDADDR)
bdwrite(ibp);
This patch corrects the first round of panics and hangs reported with the new snapshot code. Update addaliasu to correctly implement the semantics of the old checkalias function. When a device vnode first comes into existence, check to see if an anonymous vnode for the same device was created at boot time by bdevvp(). If so, adopt the bdevvp vnode rather than creating a new vnode for the device. This corrects a problem which caused the kernel to panic when taking a snapshot of the root filesystem. Change the calling convention of vn_write_suspend_wait() to be the same as vn_start_write(). Split out softdep_flushworklist() from softdep_flushfiles() so that it can be used to clear the work queue when suspending filesystem operations. Access to buffers becomes recursive so that snapshots can recursively traverse their indirect blocks using ffs_copyonwrite() when checking for the need for copy on write when flushing one of their own indirect blocks. This eliminates a deadlock between the syncer daemon and a process taking a snapshot. Ensure that softdep_process_worklist() can never block because of a snapshot being taken. This eliminates a problem with buffer starvation. Cleanup change in ffs_sync() which did not synchronously wait when MNT_WAIT was specified. The result was an unclean filesystem panic when doing forcible unmount with heavy filesystem I/O in progress. Return a zero'ed block when reading a block that was not in use at the time that a snapshot was taken. Normally, these blocks should never be read. However, the readahead code will occationally read them which can cause unexpected behavior. Clean up the debugging code that ensures that no blocks be written on a filesystem while it is suspended. Snapshots must explicitly label the blocks that they are writing during the suspension so that they do not cause a `write on suspended filesystem' panic. Reorganize ffs_copyonwrite() to eliminate a deadlock and also to prevent a race condition that would permit the same block to be copied twice. This change eliminates an unexpected soft updates inconsistency in fsck caused by the double allocation. Use bqrelse rather than brelse for buffers that will be needed soon again by the snapshot code. This improves snapshot performance.
2000-07-24 05:28:33 +00:00
}
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
}
return (0);
}
Refinement to revision 1.16 of ufs/ffs/ffs_snapshot.c to reduce the amount of time that the filesystem must be suspended. The current snapshot is elided as well as the earlier snapshots.
2001-05-04 05:49:28 +00:00
/*
* Account for a set of blocks allocated in a snapshot inode.
*/
static int
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
mapacct(vp, oldblkp, lastblkp, fs, lblkno, expungetype)
Refinement to revision 1.16 of ufs/ffs/ffs_snapshot.c to reduce the amount of time that the filesystem must be suspended. The current snapshot is elided as well as the earlier snapshots.
2001-05-04 05:49:28 +00:00
struct vnode *vp;
ufs_daddr_t *oldblkp, *lastblkp;
struct fs *fs;
ufs_daddr_t lblkno;
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
int expungetype;
Refinement to revision 1.16 of ufs/ffs/ffs_snapshot.c to reduce the amount of time that the filesystem must be suspended. The current snapshot is elided as well as the earlier snapshots.
2001-05-04 05:49:28 +00:00
{
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
ufs_daddr_t blkno;
ino_t inum;
Refinement to revision 1.16 of ufs/ffs/ffs_snapshot.c to reduce the amount of time that the filesystem must be suspended. The current snapshot is elided as well as the earlier snapshots.
2001-05-04 05:49:28 +00:00
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
inum = VTOI(vp)->i_number;
Refinement to revision 1.16 of ufs/ffs/ffs_snapshot.c to reduce the amount of time that the filesystem must be suspended. The current snapshot is elided as well as the earlier snapshots.
2001-05-04 05:49:28 +00:00
for ( ; oldblkp < lastblkp; oldblkp++, lblkno++) {
blkno = *oldblkp;
if (blkno == 0 || blkno == BLK_NOCOPY)
continue;
if (blkno == BLK_SNAP)
blkno = blkstofrags(fs, lblkno);
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
ffs_blkfree(fs, vp, blkno, fs->fs_bsize, inum);
Refinement to revision 1.16 of ufs/ffs/ffs_snapshot.c to reduce the amount of time that the filesystem must be suspended. The current snapshot is elided as well as the earlier snapshots.
2001-05-04 05:49:28 +00:00
}
return (0);
}
Several small but important fixes for snapshots: 1) Be more tolerant of missing snapshot files by only trying to decrement their reference count if they are registered as active. 2) Fix for snapshots of filesystems with block sizes larger than 8K (from Ollivier Robert <roberto@eurocontrol.fr>). 3) Fix to avoid losing last block in snapshot file when calculating blocks that need to be copied (from Don Coleman <coleman@coleman.org>).
2000-12-19 04:41:09 +00:00
/*
* Decrement extra reference on snapshot when last name is removed.
* It will not be freed until the last open reference goes away.
*/
void
ffs_snapgone(ip)
struct inode *ip;
{
struct inode *xp;
Clear the fs_clean flag only when the FS_UNCLEAN flag is not set (as is done in unmount). Remove a snapshot inode from the superblock list when its last name goes away rather than when its last reference goes away. That way it will be properly reclaimed by fsck after a crash rather than reenabled when the filesystem is mounted.
2001-03-21 04:05:20 +00:00
struct fs *fs;
int snaploc;
Several small but important fixes for snapshots: 1) Be more tolerant of missing snapshot files by only trying to decrement their reference count if they are registered as active. 2) Fix for snapshots of filesystems with block sizes larger than 8K (from Ollivier Robert <roberto@eurocontrol.fr>). 3) Fix to avoid losing last block in snapshot file when calculating blocks that need to be copied (from Don Coleman <coleman@coleman.org>).
2000-12-19 04:41:09 +00:00
/*
* Find snapshot in incore list.
*/
Fixes to track snapshot copy-on-write checking in the specinfo structure rather than assuming that the device vnode would reside in the FFS filesystem (which is obviously a broken assumption with the device filesystem).
2001-03-07 07:09:55 +00:00
TAILQ_FOREACH(xp, &ip->i_devvp->v_rdev->si_snapshots, i_nextsnap)
if (xp == ip)
Several small but important fixes for snapshots: 1) Be more tolerant of missing snapshot files by only trying to decrement their reference count if they are registered as active. 2) Fix for snapshots of filesystems with block sizes larger than 8K (from Ollivier Robert <roberto@eurocontrol.fr>). 3) Fix to avoid losing last block in snapshot file when calculating blocks that need to be copied (from Don Coleman <coleman@coleman.org>).
2000-12-19 04:41:09 +00:00
break;
if (xp == 0)
printf("ffs_snapgone: lost snapshot vnode %d\n",
ip->i_number);
else
vrele(ITOV(ip));
Clear the fs_clean flag only when the FS_UNCLEAN flag is not set (as is done in unmount). Remove a snapshot inode from the superblock list when its last name goes away rather than when its last reference goes away. That way it will be properly reclaimed by fsck after a crash rather than reenabled when the filesystem is mounted.
2001-03-21 04:05:20 +00:00
/*
* Delete snapshot inode from superblock. Keep list dense.
*/
fs = ip->i_fs;
for (snaploc = 0; snaploc < FSMAXSNAP; snaploc++)
if (fs->fs_snapinum[snaploc] == ip->i_number)
break;
if (snaploc < FSMAXSNAP) {
for (snaploc++; snaploc < FSMAXSNAP; snaploc++) {
if (fs->fs_snapinum[snaploc] == 0)
break;
fs->fs_snapinum[snaploc - 1] = fs->fs_snapinum[snaploc];
}
fs->fs_snapinum[snaploc - 1] = 0;
}
Several small but important fixes for snapshots: 1) Be more tolerant of missing snapshot files by only trying to decrement their reference count if they are registered as active. 2) Fix for snapshots of filesystems with block sizes larger than 8K (from Ollivier Robert <roberto@eurocontrol.fr>). 3) Fix to avoid losing last block in snapshot file when calculating blocks that need to be copied (from Don Coleman <coleman@coleman.org>).
2000-12-19 04:41:09 +00:00
}
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
/*
* Prepare a snapshot file for being removed.
*/
void
ffs_snapremove(vp)
struct vnode *vp;
{
Fixes to track snapshot copy-on-write checking in the specinfo structure rather than assuming that the device vnode would reside in the FFS filesystem (which is obviously a broken assumption with the device filesystem).
2001-03-07 07:09:55 +00:00
struct inode *ip;
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
struct vnode *devvp;
struct buf *ibp;
struct fs *fs;
ufs_daddr_t blkno, dblk;
Several fixes for units errors: 1) Do not assume that the superblock will be of size fs->fs_bsize. This fixes a panic when taking a snapshot on a filesystem with a block size bigger than 8K. 2) Properly calculate the number of fragments that follow the superblock summary information. This fixes a bug with inconsistent snapshots. 3) When cleaning up a snapshot that is about to be removed, properly calculate the number of blocks that need to be checked. This fixes a bug that created partially allocated inodes. 4) When moving blocks from a snapshot that is about to be removed to another snapshot, properly account for the reduced number of blocks in the snapshot from which they are taken. This fixes a bug in which the number of blocks released from a snapshot did not match the number that it claimed to have.
2001-05-08 07:29:03 +00:00
int error, numblks, loc, last;
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
ip = VTOI(vp);
fs = ip->i_fs;
/*
When closing the last reference to an unlinked file, it is freed by the inactive routine. Because the freeing causes the filesystem to be modified, the close must be held up during periods when the filesystem is suspended. For snapshots to be consistent across crashes, they must write blocks that they copy and claim those written blocks in their on-disk block pointers before the old blocks that they referenced can be allowed to be written. Close a loophole that allowed unwritten blocks to be skipped when doing ffs_sync with a request to wait for all I/O activity to be completed.
2001-04-25 08:11:18 +00:00
* If active, delete from incore list (this snapshot may
* already have been in the process of being deleted, so
* would not have been active).
*
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
* Clear copy-on-write flag if last snapshot.
*/
When closing the last reference to an unlinked file, it is freed by the inactive routine. Because the freeing causes the filesystem to be modified, the close must be held up during periods when the filesystem is suspended. For snapshots to be consistent across crashes, they must write blocks that they copy and claim those written blocks in their on-disk block pointers before the old blocks that they referenced can be allowed to be written. Close a loophole that allowed unwritten blocks to be skipped when doing ffs_sync with a request to wait for all I/O activity to be completed.
2001-04-25 08:11:18 +00:00
if (ip->i_nextsnap.tqe_prev != 0) {
devvp = ip->i_devvp;
Fixes to track snapshot copy-on-write checking in the specinfo structure rather than assuming that the device vnode would reside in the FFS filesystem (which is obviously a broken assumption with the device filesystem).
2001-03-07 07:09:55 +00:00
TAILQ_REMOVE(&devvp->v_rdev->si_snapshots, ip, i_nextsnap);
ip->i_nextsnap.tqe_prev = 0;
if (TAILQ_FIRST(&devvp->v_rdev->si_snapshots) == 0) {
devvp->v_rdev->si_copyonwrite = 0;
devvp->v_flag &= ~VCOPYONWRITE;
}
}
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
/*
* Clear all BLK_NOCOPY fields. Pass any block claims to other
* snapshots that want them (see ffs_snapblkfree below).
*/
for (blkno = 1; blkno < NDADDR; blkno++) {
dblk = ip->i_db[blkno];
Several fixes for units errors: 1) Do not assume that the superblock will be of size fs->fs_bsize. This fixes a panic when taking a snapshot on a filesystem with a block size bigger than 8K. 2) Properly calculate the number of fragments that follow the superblock summary information. This fixes a bug with inconsistent snapshots. 3) When cleaning up a snapshot that is about to be removed, properly calculate the number of blocks that need to be checked. This fixes a bug that created partially allocated inodes. 4) When moving blocks from a snapshot that is about to be removed to another snapshot, properly account for the reduced number of blocks in the snapshot from which they are taken. This fixes a bug in which the number of blocks released from a snapshot did not match the number that it claimed to have.
2001-05-08 07:29:03 +00:00
if (dblk == BLK_NOCOPY || dblk == BLK_SNAP)
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
ip->i_db[blkno] = 0;
Several fixes for units errors: 1) Do not assume that the superblock will be of size fs->fs_bsize. This fixes a panic when taking a snapshot on a filesystem with a block size bigger than 8K. 2) Properly calculate the number of fragments that follow the superblock summary information. This fixes a bug with inconsistent snapshots. 3) When cleaning up a snapshot that is about to be removed, properly calculate the number of blocks that need to be checked. This fixes a bug that created partially allocated inodes. 4) When moving blocks from a snapshot that is about to be removed to another snapshot, properly account for the reduced number of blocks in the snapshot from which they are taken. This fixes a bug in which the number of blocks released from a snapshot did not match the number that it claimed to have.
2001-05-08 07:29:03 +00:00
else if ((dblk == blkstofrags(fs, blkno) &&
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
ffs_snapblkfree(fs, ip->i_devvp, dblk, fs->fs_bsize,
ip->i_number))) {
Several fixes for units errors: 1) Do not assume that the superblock will be of size fs->fs_bsize. This fixes a panic when taking a snapshot on a filesystem with a block size bigger than 8K. 2) Properly calculate the number of fragments that follow the superblock summary information. This fixes a bug with inconsistent snapshots. 3) When cleaning up a snapshot that is about to be removed, properly calculate the number of blocks that need to be checked. This fixes a bug that created partially allocated inodes. 4) When moving blocks from a snapshot that is about to be removed to another snapshot, properly account for the reduced number of blocks in the snapshot from which they are taken. This fixes a bug in which the number of blocks released from a snapshot did not match the number that it claimed to have.
2001-05-08 07:29:03 +00:00
ip->i_blocks -= btodb(fs->fs_bsize);
ip->i_db[blkno] = 0;
}
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
}
Several fixes for units errors: 1) Do not assume that the superblock will be of size fs->fs_bsize. This fixes a panic when taking a snapshot on a filesystem with a block size bigger than 8K. 2) Properly calculate the number of fragments that follow the superblock summary information. This fixes a bug with inconsistent snapshots. 3) When cleaning up a snapshot that is about to be removed, properly calculate the number of blocks that need to be checked. This fixes a bug that created partially allocated inodes. 4) When moving blocks from a snapshot that is about to be removed to another snapshot, properly account for the reduced number of blocks in the snapshot from which they are taken. This fixes a bug in which the number of blocks released from a snapshot did not match the number that it claimed to have.
2001-05-08 07:29:03 +00:00
numblks = howmany(ip->i_size, fs->fs_bsize);
for (blkno = NDADDR; blkno < numblks; blkno += NINDIR(fs)) {
VOP_BALLOC was never really a VOP in the first place, so convert it to UFS_BALLOC like the other "between UFS and FFS function interfaces".
2001-04-29 12:36:52 +00:00
error = UFS_BALLOC(vp, lblktosize(fs, (off_t)blkno),
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
fs->fs_bsize, KERNCRED, B_METAONLY, &ibp);
if (error)
continue;
if ((last = fs->fs_size - blkno) > NINDIR(fs))
last = NINDIR(fs);
for (loc = 0; loc < last; loc++) {
dblk = ((ufs_daddr_t *)(ibp->b_data))[loc];
Several fixes for units errors: 1) Do not assume that the superblock will be of size fs->fs_bsize. This fixes a panic when taking a snapshot on a filesystem with a block size bigger than 8K. 2) Properly calculate the number of fragments that follow the superblock summary information. This fixes a bug with inconsistent snapshots. 3) When cleaning up a snapshot that is about to be removed, properly calculate the number of blocks that need to be checked. This fixes a bug that created partially allocated inodes. 4) When moving blocks from a snapshot that is about to be removed to another snapshot, properly account for the reduced number of blocks in the snapshot from which they are taken. This fixes a bug in which the number of blocks released from a snapshot did not match the number that it claimed to have.
2001-05-08 07:29:03 +00:00
if (dblk == BLK_NOCOPY || dblk == BLK_SNAP)
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
((ufs_daddr_t *)(ibp->b_data))[loc] = 0;
Several fixes for units errors: 1) Do not assume that the superblock will be of size fs->fs_bsize. This fixes a panic when taking a snapshot on a filesystem with a block size bigger than 8K. 2) Properly calculate the number of fragments that follow the superblock summary information. This fixes a bug with inconsistent snapshots. 3) When cleaning up a snapshot that is about to be removed, properly calculate the number of blocks that need to be checked. This fixes a bug that created partially allocated inodes. 4) When moving blocks from a snapshot that is about to be removed to another snapshot, properly account for the reduced number of blocks in the snapshot from which they are taken. This fixes a bug in which the number of blocks released from a snapshot did not match the number that it claimed to have.
2001-05-08 07:29:03 +00:00
else if ((dblk == blkstofrags(fs, blkno) &&
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
ffs_snapblkfree(fs, ip->i_devvp, dblk,
fs->fs_bsize, ip->i_number))) {
Several fixes for units errors: 1) Do not assume that the superblock will be of size fs->fs_bsize. This fixes a panic when taking a snapshot on a filesystem with a block size bigger than 8K. 2) Properly calculate the number of fragments that follow the superblock summary information. This fixes a bug with inconsistent snapshots. 3) When cleaning up a snapshot that is about to be removed, properly calculate the number of blocks that need to be checked. This fixes a bug that created partially allocated inodes. 4) When moving blocks from a snapshot that is about to be removed to another snapshot, properly account for the reduced number of blocks in the snapshot from which they are taken. This fixes a bug in which the number of blocks released from a snapshot did not match the number that it claimed to have.
2001-05-08 07:29:03 +00:00
ip->i_blocks -= btodb(fs->fs_bsize);
((ufs_daddr_t *)(ibp->b_data))[loc] = 0;
}
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
}
bawrite(ibp);
}
/*
* Clear snapshot flag and drop reference.
*/
Clean up the snapshot code so that it no longer depends on the use of the SF_IMMUTABLE flag to prevent writing. Instead put in explicit checking for the SF_SNAPSHOT flag in the appropriate places. With this change, it is now possible to rename and link to snapshot files. It is also possible to set or clear any of the owner, group, or other read bits on the file, though none of the write or execute bits can be set. There is also an explicit test to prevent the setting or clearing of the SF_SNAPSHOT flag via chflags() or fchflags(). Note also that the modify time cannot be changed as it needs to accurately reflect the time that the snapshot was taken. Submitted by: Robert Watson <rwatson@FreeBSD.org>
2000-07-26 23:07:01 +00:00
ip->i_flags &= ~SF_SNAPSHOT;
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
ip->i_flag |= IN_CHANGE | IN_UPDATE;
}
/*
* Notification that a block is being freed. Return zero if the free
* should be allowed to proceed. Return non-zero if the snapshot file
* wants to claim the block. The block will be claimed if it is an
* uncopied part of one of the snapshots. It will be freed if it is
* either a BLK_NOCOPY or has already been copied in all of the snapshots.
* If a fragment is being freed, then all snapshots that care about
* it must make a copy since a snapshot file can only claim full sized
* blocks. Note that if more than one snapshot file maps the block,
* we can pick one at random to claim it. Since none of the snapshots
* can change, we are assurred that they will all see the same unmodified
* image. When deleting a snapshot file (see ffs_snapremove above), we
* must push any of these claimed blocks to one of the other snapshots
* that maps it. These claimed blocks are easily identified as they will
* have a block number equal to their logical block number within the
* snapshot. A copied block can never have this property because they
* must always have been allocated from a BLK_NOCOPY location.
*/
int
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
ffs_snapblkfree(fs, devvp, bno, size, inum)
struct fs *fs;
struct vnode *devvp;
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
ufs_daddr_t bno;
long size;
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
ino_t inum;
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
{
struct buf *ibp, *cbp, *savedcbp = 0;
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
struct thread *td = curthread;
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
struct inode *ip;
struct vnode *vp;
ufs_daddr_t lbn, blkno;
int indiroff = 0, error = 0, claimedblk = 0;
Fixes to track snapshot copy-on-write checking in the specinfo structure rather than assuming that the device vnode would reside in the FFS filesystem (which is obviously a broken assumption with the device filesystem).
2001-03-07 07:09:55 +00:00
struct snaphead *snaphead;
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
lbn = fragstoblks(fs, bno);
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
snaphead = &devvp->v_rdev->si_snapshots;
Fixes to track snapshot copy-on-write checking in the specinfo structure rather than assuming that the device vnode would reside in the FFS filesystem (which is obviously a broken assumption with the device filesystem).
2001-03-07 07:09:55 +00:00
TAILQ_FOREACH(ip, snaphead, i_nextsnap) {
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
vp = ITOV(ip);
/*
* Lookup block being written.
*/
if (lbn < NDADDR) {
blkno = ip->i_db[lbn];
} else {
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
td->td_proc->p_flag |= P_COWINPROGRESS;
VOP_BALLOC was never really a VOP in the first place, so convert it to UFS_BALLOC like the other "between UFS and FFS function interfaces".
2001-04-29 12:36:52 +00:00
error = UFS_BALLOC(vp, lblktosize(fs, (off_t)lbn),
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
fs->fs_bsize, KERNCRED, B_METAONLY, &ibp);
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
td->td_proc->p_flag &= ~P_COWINPROGRESS;
VOP_UNLOCK(vp, 0, td);
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
if (error)
break;
indiroff = (lbn - NDADDR) % NINDIR(fs);
blkno = ((ufs_daddr_t *)(ibp->b_data))[indiroff];
}
/*
* Check to see if block needs to be copied.
*/
switch (blkno) {
/*
* If the snapshot has already copied the block (default),
* or does not care about the block, it is not needed.
*/
default:
case BLK_NOCOPY:
if (lbn >= NDADDR)
This patch corrects the first round of panics and hangs reported with the new snapshot code. Update addaliasu to correctly implement the semantics of the old checkalias function. When a device vnode first comes into existence, check to see if an anonymous vnode for the same device was created at boot time by bdevvp(). If so, adopt the bdevvp vnode rather than creating a new vnode for the device. This corrects a problem which caused the kernel to panic when taking a snapshot of the root filesystem. Change the calling convention of vn_write_suspend_wait() to be the same as vn_start_write(). Split out softdep_flushworklist() from softdep_flushfiles() so that it can be used to clear the work queue when suspending filesystem operations. Access to buffers becomes recursive so that snapshots can recursively traverse their indirect blocks using ffs_copyonwrite() when checking for the need for copy on write when flushing one of their own indirect blocks. This eliminates a deadlock between the syncer daemon and a process taking a snapshot. Ensure that softdep_process_worklist() can never block because of a snapshot being taken. This eliminates a problem with buffer starvation. Cleanup change in ffs_sync() which did not synchronously wait when MNT_WAIT was specified. The result was an unclean filesystem panic when doing forcible unmount with heavy filesystem I/O in progress. Return a zero'ed block when reading a block that was not in use at the time that a snapshot was taken. Normally, these blocks should never be read. However, the readahead code will occationally read them which can cause unexpected behavior. Clean up the debugging code that ensures that no blocks be written on a filesystem while it is suspended. Snapshots must explicitly label the blocks that they are writing during the suspension so that they do not cause a `write on suspended filesystem' panic. Reorganize ffs_copyonwrite() to eliminate a deadlock and also to prevent a race condition that would permit the same block to be copied twice. This change eliminates an unexpected soft updates inconsistency in fsck caused by the double allocation. Use bqrelse rather than brelse for buffers that will be needed soon again by the snapshot code. This improves snapshot performance.
2000-07-24 05:28:33 +00:00
bqrelse(ibp);
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
continue;
/*
* No previous snapshot claimed the block, so it will be
* freed and become a BLK_NOCOPY (don't care) for us.
*/
case BLK_SNAP:
if (claimedblk)
panic("snapblkfree: inconsistent block type");
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
if (lbn < NDADDR) {
ip->i_db[lbn] = BLK_NOCOPY;
ip->i_flag |= IN_CHANGE | IN_UPDATE;
} else {
((ufs_daddr_t *)(ibp->b_data))[indiroff] =
BLK_NOCOPY;
bdwrite(ibp);
}
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
VOP_UNLOCK(vp, 0, td);
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
continue;
/*
* A block that we map is being freed. If it has not been
* claimed yet, we will claim or copy it (below).
*/
case 0:
claimedblk = 1;
break;
}
/*
* If this is a full size block, we will just grab it
* and assign it to the snapshot inode. Otherwise we
* will proceed to copy it. See explanation for this
* routine as to why only a single snapshot needs to
* claim this block.
*/
if (size == fs->fs_bsize) {
#ifdef DEBUG
if (snapdebug)
printf("%s %d lbn %d from inum %d\n",
"Grabonremove: snapino", ip->i_number, lbn,
When taking a snapshot, we must check for active files that have been unlinked (e.g., with a zero link count). We have to expunge all trace of these files from the snapshot so that they are neither reclaimed prematurely by fsck nor saved unnecessarily by dump.
2002-02-02 01:42:44 +00:00
inum);
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
#endif
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
if (lbn < NDADDR) {
ip->i_db[lbn] = bno;
} else {
((ufs_daddr_t *)(ibp->b_data))[indiroff] = bno;
bdwrite(ibp);
}
ip->i_blocks += btodb(size);
ip->i_flag |= IN_CHANGE | IN_UPDATE;
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
VOP_UNLOCK(vp, 0, td);
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
return (1);
}
if (lbn >= NDADDR)
This patch corrects the first round of panics and hangs reported with the new snapshot code. Update addaliasu to correctly implement the semantics of the old checkalias function. When a device vnode first comes into existence, check to see if an anonymous vnode for the same device was created at boot time by bdevvp(). If so, adopt the bdevvp vnode rather than creating a new vnode for the device. This corrects a problem which caused the kernel to panic when taking a snapshot of the root filesystem. Change the calling convention of vn_write_suspend_wait() to be the same as vn_start_write(). Split out softdep_flushworklist() from softdep_flushfiles() so that it can be used to clear the work queue when suspending filesystem operations. Access to buffers becomes recursive so that snapshots can recursively traverse their indirect blocks using ffs_copyonwrite() when checking for the need for copy on write when flushing one of their own indirect blocks. This eliminates a deadlock between the syncer daemon and a process taking a snapshot. Ensure that softdep_process_worklist() can never block because of a snapshot being taken. This eliminates a problem with buffer starvation. Cleanup change in ffs_sync() which did not synchronously wait when MNT_WAIT was specified. The result was an unclean filesystem panic when doing forcible unmount with heavy filesystem I/O in progress. Return a zero'ed block when reading a block that was not in use at the time that a snapshot was taken. Normally, these blocks should never be read. However, the readahead code will occationally read them which can cause unexpected behavior. Clean up the debugging code that ensures that no blocks be written on a filesystem while it is suspended. Snapshots must explicitly label the blocks that they are writing during the suspension so that they do not cause a `write on suspended filesystem' panic. Reorganize ffs_copyonwrite() to eliminate a deadlock and also to prevent a race condition that would permit the same block to be copied twice. This change eliminates an unexpected soft updates inconsistency in fsck caused by the double allocation. Use bqrelse rather than brelse for buffers that will be needed soon again by the snapshot code. This improves snapshot performance.
2000-07-24 05:28:33 +00:00
bqrelse(ibp);
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
/*
* Allocate the block into which to do the copy. Note that this
* allocation will never require any additional allocations for
* the snapshot inode.
*/
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
td->td_proc->p_flag |= P_COWINPROGRESS;
VOP_BALLOC was never really a VOP in the first place, so convert it to UFS_BALLOC like the other "between UFS and FFS function interfaces".
2001-04-29 12:36:52 +00:00
error = UFS_BALLOC(vp, lblktosize(fs, (off_t)lbn),
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
fs->fs_bsize, KERNCRED, 0, &cbp);
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
td->td_proc->p_flag &= ~P_COWINPROGRESS;
When closing the last reference to an unlinked file, it is freed by the inactive routine. Because the freeing causes the filesystem to be modified, the close must be held up during periods when the filesystem is suspended. For snapshots to be consistent across crashes, they must write blocks that they copy and claim those written blocks in their on-disk block pointers before the old blocks that they referenced can be allowed to be written. Close a loophole that allowed unwritten blocks to be skipped when doing ffs_sync with a request to wait for all I/O activity to be completed.
2001-04-25 08:11:18 +00:00
if (error) {
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
VOP_UNLOCK(vp, 0, td);
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
break;
When closing the last reference to an unlinked file, it is freed by the inactive routine. Because the freeing causes the filesystem to be modified, the close must be held up during periods when the filesystem is suspended. For snapshots to be consistent across crashes, they must write blocks that they copy and claim those written blocks in their on-disk block pointers before the old blocks that they referenced can be allowed to be written. Close a loophole that allowed unwritten blocks to be skipped when doing ffs_sync with a request to wait for all I/O activity to be completed.
2001-04-25 08:11:18 +00:00
}
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
#ifdef DEBUG
if (snapdebug)
Fixed some printf format errors (hopefully all of the remaining daddr64_t ones for GENERIC, and all others on the same line as those). Reformat the printfs if necessary to avoid new long lones or old format printf errors.
2002-03-19 04:09:21 +00:00
printf(
"Copyonremove: snapino %lu lbn %ld for inum %lu size %ld to blkno %lld\n",
(unsigned long)ip->i_number, (long)lbn,
(unsigned long)inum, size, (long long)cbp->b_blkno);
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
#endif
/*
* If we have already read the old block contents, then
When closing the last reference to an unlinked file, it is freed by the inactive routine. Because the freeing causes the filesystem to be modified, the close must be held up during periods when the filesystem is suspended. For snapshots to be consistent across crashes, they must write blocks that they copy and claim those written blocks in their on-disk block pointers before the old blocks that they referenced can be allowed to be written. Close a loophole that allowed unwritten blocks to be skipped when doing ffs_sync with a request to wait for all I/O activity to be completed.
2001-04-25 08:11:18 +00:00
* simply copy them to the new block. Note that we need
* to synchronously write snapshots that have not been
* unlinked, and hence will be visible after a crash,
* to ensure their integrity.
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
*/
if (savedcbp != 0) {
bcopy(savedcbp->b_data, cbp->b_data, fs->fs_bsize);
bawrite(cbp);
Further fixes for deadlock in the presence of multiple snapshots. There are still more to find, but this fix should cover the common cases that folks are hitting.
2001-05-14 17:16:49 +00:00
if (dopersistence && ip->i_effnlink > 0)
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
(void) VOP_FSYNC(vp, KERNCRED, MNT_WAIT, td);
VOP_UNLOCK(vp, 0, td);
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
continue;
}
/*
* Otherwise, read the old block contents into the buffer.
*/
When closing the last reference to an unlinked file, it is freed by the inactive routine. Because the freeing causes the filesystem to be modified, the close must be held up during periods when the filesystem is suspended. For snapshots to be consistent across crashes, they must write blocks that they copy and claim those written blocks in their on-disk block pointers before the old blocks that they referenced can be allowed to be written. Close a loophole that allowed unwritten blocks to be skipped when doing ffs_sync with a request to wait for all I/O activity to be completed.
2001-04-25 08:11:18 +00:00
if ((error = readblock(cbp, lbn)) != 0) {
bzero(cbp->b_data, fs->fs_bsize);
bawrite(cbp);
Further fixes for deadlock in the presence of multiple snapshots. There are still more to find, but this fix should cover the common cases that folks are hitting.
2001-05-14 17:16:49 +00:00
if (dopersistence && ip->i_effnlink > 0)
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
(void) VOP_FSYNC(vp, KERNCRED, MNT_WAIT, td);
VOP_UNLOCK(vp, 0, td);
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
break;
When closing the last reference to an unlinked file, it is freed by the inactive routine. Because the freeing causes the filesystem to be modified, the close must be held up during periods when the filesystem is suspended. For snapshots to be consistent across crashes, they must write blocks that they copy and claim those written blocks in their on-disk block pointers before the old blocks that they referenced can be allowed to be written. Close a loophole that allowed unwritten blocks to be skipped when doing ffs_sync with a request to wait for all I/O activity to be completed.
2001-04-25 08:11:18 +00:00
}
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
VOP_UNLOCK(vp, 0, td);
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
savedcbp = cbp;
}
When closing the last reference to an unlinked file, it is freed by the inactive routine. Because the freeing causes the filesystem to be modified, the close must be held up during periods when the filesystem is suspended. For snapshots to be consistent across crashes, they must write blocks that they copy and claim those written blocks in their on-disk block pointers before the old blocks that they referenced can be allowed to be written. Close a loophole that allowed unwritten blocks to be skipped when doing ffs_sync with a request to wait for all I/O activity to be completed.
2001-04-25 08:11:18 +00:00
/*
* Note that we need to synchronously write snapshots that
* have not been unlinked, and hence will be visible after
* a crash, to ensure their integrity.
*/
if (savedcbp) {
vp = savedcbp->b_vp;
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
bawrite(savedcbp);
Further fixes for deadlock in the presence of multiple snapshots. There are still more to find, but this fix should cover the common cases that folks are hitting.
2001-05-14 17:16:49 +00:00
if (dopersistence && VTOI(vp)->i_effnlink > 0) {
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
(void) VOP_FSYNC(vp, KERNCRED, MNT_WAIT, td);
VOP_UNLOCK(vp, 0, td);
Remove yet another deadlock case.
2001-05-11 07:12:03 +00:00
}
When closing the last reference to an unlinked file, it is freed by the inactive routine. Because the freeing causes the filesystem to be modified, the close must be held up during periods when the filesystem is suspended. For snapshots to be consistent across crashes, they must write blocks that they copy and claim those written blocks in their on-disk block pointers before the old blocks that they referenced can be allowed to be written. Close a loophole that allowed unwritten blocks to be skipped when doing ffs_sync with a request to wait for all I/O activity to be completed.
2001-04-25 08:11:18 +00:00
}
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
/*
* If we have been unable to allocate a block in which to do
* the copy, then return non-zero so that the fragment will
* not be freed. Although space will be lost, the snapshot
* will stay consistent.
*/
return (error);
}
/*
* Associate snapshot files when mounting.
*/
void
ffs_snapshot_mount(mp)
struct mount *mp;
{
struct ufsmount *ump = VFSTOUFS(mp);
struct fs *fs = ump->um_fs;
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
struct thread *td = curthread;
Fixes to track snapshot copy-on-write checking in the specinfo structure rather than assuming that the device vnode would reside in the FFS filesystem (which is obviously a broken assumption with the device filesystem).
2001-03-07 07:09:55 +00:00
struct snaphead *snaphead;
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
struct vnode *vp;
Fixes to track snapshot copy-on-write checking in the specinfo structure rather than assuming that the device vnode would reside in the FFS filesystem (which is obviously a broken assumption with the device filesystem).
2001-03-07 07:09:55 +00:00
struct inode *ip;
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
int error, snaploc, loc;
Fixes to track snapshot copy-on-write checking in the specinfo structure rather than assuming that the device vnode would reside in the FFS filesystem (which is obviously a broken assumption with the device filesystem).
2001-03-07 07:09:55 +00:00
snaphead = &ump->um_devvp->v_rdev->si_snapshots;
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
for (snaploc = 0; snaploc < FSMAXSNAP; snaploc++) {
if (fs->fs_snapinum[snaploc] == 0)
return;
Add a flags parameter to VFS_VGET to pass through the desired locking flags when acquiring a vnode. The immediate purpose is to allow polling lock requests (LK_NOWAIT) needed by soft updates to avoid deadlock when enlisting other processes to help with the background cleanup. For the future it will allow the use of shared locks for read access to vnodes. This change touches a lot of files as it affects most filesystems within the system. It has been well tested on FFS, loopback, and CD-ROM filesystems. only lightly on the others, so if you find a problem there, please let me (mckusick@mckusick.com) know.
2002-03-17 01:25:47 +00:00
if ((error = VFS_VGET(mp, fs->fs_snapinum[snaploc],
LK_EXCLUSIVE, &vp)) != 0){
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
printf("ffs_snapshot_mount: vget failed %d\n", error);
continue;
}
ip = VTOI(vp);
if ((ip->i_flags & SF_SNAPSHOT) == 0) {
printf("ffs_snapshot_mount: non-snapshot inode %d\n",
fs->fs_snapinum[snaploc]);
vput(vp);
for (loc = snaploc + 1; loc < FSMAXSNAP; loc++) {
if (fs->fs_snapinum[loc] == 0)
break;
fs->fs_snapinum[loc - 1] = fs->fs_snapinum[loc];
}
fs->fs_snapinum[loc - 1] = 0;
snaploc--;
continue;
}
Fixes to track snapshot copy-on-write checking in the specinfo structure rather than assuming that the device vnode would reside in the FFS filesystem (which is obviously a broken assumption with the device filesystem).
2001-03-07 07:09:55 +00:00
if (ip->i_nextsnap.tqe_prev != 0)
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
panic("ffs_snapshot_mount: %d already on list",
ip->i_number);
Fixes to track snapshot copy-on-write checking in the specinfo structure rather than assuming that the device vnode would reside in the FFS filesystem (which is obviously a broken assumption with the device filesystem).
2001-03-07 07:09:55 +00:00
else
TAILQ_INSERT_TAIL(snaphead, ip, i_nextsnap);
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
vp->v_flag |= VSYSTEM;
Fixes to track snapshot copy-on-write checking in the specinfo structure rather than assuming that the device vnode would reside in the FFS filesystem (which is obviously a broken assumption with the device filesystem).
2001-03-07 07:09:55 +00:00
ump->um_devvp->v_rdev->si_copyonwrite = ffs_copyonwrite;
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
ump->um_devvp->v_flag |= VCOPYONWRITE;
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
VOP_UNLOCK(vp, 0, td);
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
}
}
/*
* Disassociate snapshot files when unmounting.
*/
void
ffs_snapshot_unmount(mp)
struct mount *mp;
{
struct ufsmount *ump = VFSTOUFS(mp);
Fixes to track snapshot copy-on-write checking in the specinfo structure rather than assuming that the device vnode would reside in the FFS filesystem (which is obviously a broken assumption with the device filesystem).
2001-03-07 07:09:55 +00:00
struct snaphead *snaphead = &ump->um_devvp->v_rdev->si_snapshots;
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
struct inode *xp;
Fixes to track snapshot copy-on-write checking in the specinfo structure rather than assuming that the device vnode would reside in the FFS filesystem (which is obviously a broken assumption with the device filesystem).
2001-03-07 07:09:55 +00:00
while ((xp = TAILQ_FIRST(snaphead)) != 0) {
TAILQ_REMOVE(snaphead, xp, i_nextsnap);
xp->i_nextsnap.tqe_prev = 0;
Clean up the snapshot code so that it no longer depends on the use of the SF_IMMUTABLE flag to prevent writing. Instead put in explicit checking for the SF_SNAPSHOT flag in the appropriate places. With this change, it is now possible to rename and link to snapshot files. It is also possible to set or clear any of the owner, group, or other read bits on the file, though none of the write or execute bits can be set. There is also an explicit test to prevent the setting or clearing of the SF_SNAPSHOT flag via chflags() or fchflags(). Note also that the modify time cannot be changed as it needs to accurately reflect the time that the snapshot was taken. Submitted by: Robert Watson <rwatson@FreeBSD.org>
2000-07-26 23:07:01 +00:00
if (xp->i_effnlink > 0)
vrele(ITOV(xp));
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
}
Fixes to track snapshot copy-on-write checking in the specinfo structure rather than assuming that the device vnode would reside in the FFS filesystem (which is obviously a broken assumption with the device filesystem).
2001-03-07 07:09:55 +00:00
ump->um_devvp->v_rdev->si_copyonwrite = 0;
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
ump->um_devvp->v_flag &= ~VCOPYONWRITE;
}
/*
* Check for need to copy block that is about to be written,
* copying the block if necessary.
*/
Fixes to track snapshot copy-on-write checking in the specinfo structure rather than assuming that the device vnode would reside in the FFS filesystem (which is obviously a broken assumption with the device filesystem).
2001-03-07 07:09:55 +00:00
static int
ffs_copyonwrite(devvp, bp)
struct vnode *devvp;
struct buf *bp;
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
{
Fixes to track snapshot copy-on-write checking in the specinfo structure rather than assuming that the device vnode would reside in the FFS filesystem (which is obviously a broken assumption with the device filesystem).
2001-03-07 07:09:55 +00:00
struct buf *ibp, *cbp, *savedcbp = 0;
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
struct thread *td = curthread;
Fixes to track snapshot copy-on-write checking in the specinfo structure rather than assuming that the device vnode would reside in the FFS filesystem (which is obviously a broken assumption with the device filesystem).
2001-03-07 07:09:55 +00:00
struct fs *fs;
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
struct inode *ip;
struct vnode *vp;
ufs_daddr_t lbn, blkno;
int indiroff, error = 0;
Fixes to track snapshot copy-on-write checking in the specinfo structure rather than assuming that the device vnode would reside in the FFS filesystem (which is obviously a broken assumption with the device filesystem).
2001-03-07 07:09:55 +00:00
fs = TAILQ_FIRST(&devvp->v_rdev->si_snapshots)->i_fs;
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
lbn = fragstoblks(fs, dbtofsb(fs, bp->b_blkno));
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
if (td->td_proc->p_flag & P_COWINPROGRESS)
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
panic("ffs_copyonwrite: recursive call");
Fixes to track snapshot copy-on-write checking in the specinfo structure rather than assuming that the device vnode would reside in the FFS filesystem (which is obviously a broken assumption with the device filesystem).
2001-03-07 07:09:55 +00:00
TAILQ_FOREACH(ip, &devvp->v_rdev->si_snapshots, i_nextsnap) {
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
vp = ITOV(ip);
/*
* We ensure that everything of our own that needs to be
* copied will be done at the time that ffs_snapshot is
* called. Thus we can skip the check here which can
VOP_BALLOC was never really a VOP in the first place, so convert it to UFS_BALLOC like the other "between UFS and FFS function interfaces".
2001-04-29 12:36:52 +00:00
* deadlock in doing the lookup in UFS_BALLOC.
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
*/
if (bp->b_vp == vp)
continue;
/*
This patch corrects the first round of panics and hangs reported with the new snapshot code. Update addaliasu to correctly implement the semantics of the old checkalias function. When a device vnode first comes into existence, check to see if an anonymous vnode for the same device was created at boot time by bdevvp(). If so, adopt the bdevvp vnode rather than creating a new vnode for the device. This corrects a problem which caused the kernel to panic when taking a snapshot of the root filesystem. Change the calling convention of vn_write_suspend_wait() to be the same as vn_start_write(). Split out softdep_flushworklist() from softdep_flushfiles() so that it can be used to clear the work queue when suspending filesystem operations. Access to buffers becomes recursive so that snapshots can recursively traverse their indirect blocks using ffs_copyonwrite() when checking for the need for copy on write when flushing one of their own indirect blocks. This eliminates a deadlock between the syncer daemon and a process taking a snapshot. Ensure that softdep_process_worklist() can never block because of a snapshot being taken. This eliminates a problem with buffer starvation. Cleanup change in ffs_sync() which did not synchronously wait when MNT_WAIT was specified. The result was an unclean filesystem panic when doing forcible unmount with heavy filesystem I/O in progress. Return a zero'ed block when reading a block that was not in use at the time that a snapshot was taken. Normally, these blocks should never be read. However, the readahead code will occationally read them which can cause unexpected behavior. Clean up the debugging code that ensures that no blocks be written on a filesystem while it is suspended. Snapshots must explicitly label the blocks that they are writing during the suspension so that they do not cause a `write on suspended filesystem' panic. Reorganize ffs_copyonwrite() to eliminate a deadlock and also to prevent a race condition that would permit the same block to be copied twice. This change eliminates an unexpected soft updates inconsistency in fsck caused by the double allocation. Use bqrelse rather than brelse for buffers that will be needed soon again by the snapshot code. This improves snapshot performance.
2000-07-24 05:28:33 +00:00
* Check to see if block needs to be copied. We have to
VOP_BALLOC was never really a VOP in the first place, so convert it to UFS_BALLOC like the other "between UFS and FFS function interfaces".
2001-04-29 12:36:52 +00:00
* be able to do the UFS_BALLOC without blocking, otherwise
This patch corrects the first round of panics and hangs reported with the new snapshot code. Update addaliasu to correctly implement the semantics of the old checkalias function. When a device vnode first comes into existence, check to see if an anonymous vnode for the same device was created at boot time by bdevvp(). If so, adopt the bdevvp vnode rather than creating a new vnode for the device. This corrects a problem which caused the kernel to panic when taking a snapshot of the root filesystem. Change the calling convention of vn_write_suspend_wait() to be the same as vn_start_write(). Split out softdep_flushworklist() from softdep_flushfiles() so that it can be used to clear the work queue when suspending filesystem operations. Access to buffers becomes recursive so that snapshots can recursively traverse their indirect blocks using ffs_copyonwrite() when checking for the need for copy on write when flushing one of their own indirect blocks. This eliminates a deadlock between the syncer daemon and a process taking a snapshot. Ensure that softdep_process_worklist() can never block because of a snapshot being taken. This eliminates a problem with buffer starvation. Cleanup change in ffs_sync() which did not synchronously wait when MNT_WAIT was specified. The result was an unclean filesystem panic when doing forcible unmount with heavy filesystem I/O in progress. Return a zero'ed block when reading a block that was not in use at the time that a snapshot was taken. Normally, these blocks should never be read. However, the readahead code will occationally read them which can cause unexpected behavior. Clean up the debugging code that ensures that no blocks be written on a filesystem while it is suspended. Snapshots must explicitly label the blocks that they are writing during the suspension so that they do not cause a `write on suspended filesystem' panic. Reorganize ffs_copyonwrite() to eliminate a deadlock and also to prevent a race condition that would permit the same block to be copied twice. This change eliminates an unexpected soft updates inconsistency in fsck caused by the double allocation. Use bqrelse rather than brelse for buffers that will be needed soon again by the snapshot code. This improves snapshot performance.
2000-07-24 05:28:33 +00:00
* we may get in a deadlock with another process also
* trying to allocate. If we find outselves unable to
* get the buffer lock, we unlock the snapshot vnode,
* sleep briefly, and try again.
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
*/
This patch corrects the first round of panics and hangs reported with the new snapshot code. Update addaliasu to correctly implement the semantics of the old checkalias function. When a device vnode first comes into existence, check to see if an anonymous vnode for the same device was created at boot time by bdevvp(). If so, adopt the bdevvp vnode rather than creating a new vnode for the device. This corrects a problem which caused the kernel to panic when taking a snapshot of the root filesystem. Change the calling convention of vn_write_suspend_wait() to be the same as vn_start_write(). Split out softdep_flushworklist() from softdep_flushfiles() so that it can be used to clear the work queue when suspending filesystem operations. Access to buffers becomes recursive so that snapshots can recursively traverse their indirect blocks using ffs_copyonwrite() when checking for the need for copy on write when flushing one of their own indirect blocks. This eliminates a deadlock between the syncer daemon and a process taking a snapshot. Ensure that softdep_process_worklist() can never block because of a snapshot being taken. This eliminates a problem with buffer starvation. Cleanup change in ffs_sync() which did not synchronously wait when MNT_WAIT was specified. The result was an unclean filesystem panic when doing forcible unmount with heavy filesystem I/O in progress. Return a zero'ed block when reading a block that was not in use at the time that a snapshot was taken. Normally, these blocks should never be read. However, the readahead code will occationally read them which can cause unexpected behavior. Clean up the debugging code that ensures that no blocks be written on a filesystem while it is suspended. Snapshots must explicitly label the blocks that they are writing during the suspension so that they do not cause a `write on suspended filesystem' panic. Reorganize ffs_copyonwrite() to eliminate a deadlock and also to prevent a race condition that would permit the same block to be copied twice. This change eliminates an unexpected soft updates inconsistency in fsck caused by the double allocation. Use bqrelse rather than brelse for buffers that will be needed soon again by the snapshot code. This improves snapshot performance.
2000-07-24 05:28:33 +00:00
retry:
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
if (lbn < NDADDR) {
blkno = ip->i_db[lbn];
} else {
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
td->td_proc->p_flag |= P_COWINPROGRESS;
VOP_BALLOC was never really a VOP in the first place, so convert it to UFS_BALLOC like the other "between UFS and FFS function interfaces".
2001-04-29 12:36:52 +00:00
error = UFS_BALLOC(vp, lblktosize(fs, (off_t)lbn),
This patch corrects the first round of panics and hangs reported with the new snapshot code. Update addaliasu to correctly implement the semantics of the old checkalias function. When a device vnode first comes into existence, check to see if an anonymous vnode for the same device was created at boot time by bdevvp(). If so, adopt the bdevvp vnode rather than creating a new vnode for the device. This corrects a problem which caused the kernel to panic when taking a snapshot of the root filesystem. Change the calling convention of vn_write_suspend_wait() to be the same as vn_start_write(). Split out softdep_flushworklist() from softdep_flushfiles() so that it can be used to clear the work queue when suspending filesystem operations. Access to buffers becomes recursive so that snapshots can recursively traverse their indirect blocks using ffs_copyonwrite() when checking for the need for copy on write when flushing one of their own indirect blocks. This eliminates a deadlock between the syncer daemon and a process taking a snapshot. Ensure that softdep_process_worklist() can never block because of a snapshot being taken. This eliminates a problem with buffer starvation. Cleanup change in ffs_sync() which did not synchronously wait when MNT_WAIT was specified. The result was an unclean filesystem panic when doing forcible unmount with heavy filesystem I/O in progress. Return a zero'ed block when reading a block that was not in use at the time that a snapshot was taken. Normally, these blocks should never be read. However, the readahead code will occationally read them which can cause unexpected behavior. Clean up the debugging code that ensures that no blocks be written on a filesystem while it is suspended. Snapshots must explicitly label the blocks that they are writing during the suspension so that they do not cause a `write on suspended filesystem' panic. Reorganize ffs_copyonwrite() to eliminate a deadlock and also to prevent a race condition that would permit the same block to be copied twice. This change eliminates an unexpected soft updates inconsistency in fsck caused by the double allocation. Use bqrelse rather than brelse for buffers that will be needed soon again by the snapshot code. This improves snapshot performance.
2000-07-24 05:28:33 +00:00
fs->fs_bsize, KERNCRED, B_METAONLY | B_NOWAIT, &ibp);
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
td->td_proc->p_flag &= ~P_COWINPROGRESS;
This patch corrects the first round of panics and hangs reported with the new snapshot code. Update addaliasu to correctly implement the semantics of the old checkalias function. When a device vnode first comes into existence, check to see if an anonymous vnode for the same device was created at boot time by bdevvp(). If so, adopt the bdevvp vnode rather than creating a new vnode for the device. This corrects a problem which caused the kernel to panic when taking a snapshot of the root filesystem. Change the calling convention of vn_write_suspend_wait() to be the same as vn_start_write(). Split out softdep_flushworklist() from softdep_flushfiles() so that it can be used to clear the work queue when suspending filesystem operations. Access to buffers becomes recursive so that snapshots can recursively traverse their indirect blocks using ffs_copyonwrite() when checking for the need for copy on write when flushing one of their own indirect blocks. This eliminates a deadlock between the syncer daemon and a process taking a snapshot. Ensure that softdep_process_worklist() can never block because of a snapshot being taken. This eliminates a problem with buffer starvation. Cleanup change in ffs_sync() which did not synchronously wait when MNT_WAIT was specified. The result was an unclean filesystem panic when doing forcible unmount with heavy filesystem I/O in progress. Return a zero'ed block when reading a block that was not in use at the time that a snapshot was taken. Normally, these blocks should never be read. However, the readahead code will occationally read them which can cause unexpected behavior. Clean up the debugging code that ensures that no blocks be written on a filesystem while it is suspended. Snapshots must explicitly label the blocks that they are writing during the suspension so that they do not cause a `write on suspended filesystem' panic. Reorganize ffs_copyonwrite() to eliminate a deadlock and also to prevent a race condition that would permit the same block to be copied twice. This change eliminates an unexpected soft updates inconsistency in fsck caused by the double allocation. Use bqrelse rather than brelse for buffers that will be needed soon again by the snapshot code. This improves snapshot performance.
2000-07-24 05:28:33 +00:00
if (error) {
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
VOP_UNLOCK(vp, 0, td);
This patch corrects the first round of panics and hangs reported with the new snapshot code. Update addaliasu to correctly implement the semantics of the old checkalias function. When a device vnode first comes into existence, check to see if an anonymous vnode for the same device was created at boot time by bdevvp(). If so, adopt the bdevvp vnode rather than creating a new vnode for the device. This corrects a problem which caused the kernel to panic when taking a snapshot of the root filesystem. Change the calling convention of vn_write_suspend_wait() to be the same as vn_start_write(). Split out softdep_flushworklist() from softdep_flushfiles() so that it can be used to clear the work queue when suspending filesystem operations. Access to buffers becomes recursive so that snapshots can recursively traverse their indirect blocks using ffs_copyonwrite() when checking for the need for copy on write when flushing one of their own indirect blocks. This eliminates a deadlock between the syncer daemon and a process taking a snapshot. Ensure that softdep_process_worklist() can never block because of a snapshot being taken. This eliminates a problem with buffer starvation. Cleanup change in ffs_sync() which did not synchronously wait when MNT_WAIT was specified. The result was an unclean filesystem panic when doing forcible unmount with heavy filesystem I/O in progress. Return a zero'ed block when reading a block that was not in use at the time that a snapshot was taken. Normally, these blocks should never be read. However, the readahead code will occationally read them which can cause unexpected behavior. Clean up the debugging code that ensures that no blocks be written on a filesystem while it is suspended. Snapshots must explicitly label the blocks that they are writing during the suspension so that they do not cause a `write on suspended filesystem' panic. Reorganize ffs_copyonwrite() to eliminate a deadlock and also to prevent a race condition that would permit the same block to be copied twice. This change eliminates an unexpected soft updates inconsistency in fsck caused by the double allocation. Use bqrelse rather than brelse for buffers that will be needed soon again by the snapshot code. This improves snapshot performance.
2000-07-24 05:28:33 +00:00
if (error != EWOULDBLOCK)
break;
In a threaded world, differnt priorirites become properties of different entities. Make it so. Reviewed by: jhb@freebsd.org (john baldwin)
2002-02-11 20:37:54 +00:00
tsleep(vp, td->td_ksegrp->kg_user_pri, "nap", 1);
This patch corrects the first round of panics and hangs reported with the new snapshot code. Update addaliasu to correctly implement the semantics of the old checkalias function. When a device vnode first comes into existence, check to see if an anonymous vnode for the same device was created at boot time by bdevvp(). If so, adopt the bdevvp vnode rather than creating a new vnode for the device. This corrects a problem which caused the kernel to panic when taking a snapshot of the root filesystem. Change the calling convention of vn_write_suspend_wait() to be the same as vn_start_write(). Split out softdep_flushworklist() from softdep_flushfiles() so that it can be used to clear the work queue when suspending filesystem operations. Access to buffers becomes recursive so that snapshots can recursively traverse their indirect blocks using ffs_copyonwrite() when checking for the need for copy on write when flushing one of their own indirect blocks. This eliminates a deadlock between the syncer daemon and a process taking a snapshot. Ensure that softdep_process_worklist() can never block because of a snapshot being taken. This eliminates a problem with buffer starvation. Cleanup change in ffs_sync() which did not synchronously wait when MNT_WAIT was specified. The result was an unclean filesystem panic when doing forcible unmount with heavy filesystem I/O in progress. Return a zero'ed block when reading a block that was not in use at the time that a snapshot was taken. Normally, these blocks should never be read. However, the readahead code will occationally read them which can cause unexpected behavior. Clean up the debugging code that ensures that no blocks be written on a filesystem while it is suspended. Snapshots must explicitly label the blocks that they are writing during the suspension so that they do not cause a `write on suspended filesystem' panic. Reorganize ffs_copyonwrite() to eliminate a deadlock and also to prevent a race condition that would permit the same block to be copied twice. This change eliminates an unexpected soft updates inconsistency in fsck caused by the double allocation. Use bqrelse rather than brelse for buffers that will be needed soon again by the snapshot code. This improves snapshot performance.
2000-07-24 05:28:33 +00:00
goto retry;
}
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
indiroff = (lbn - NDADDR) % NINDIR(fs);
blkno = ((ufs_daddr_t *)(ibp->b_data))[indiroff];
This patch corrects the first round of panics and hangs reported with the new snapshot code. Update addaliasu to correctly implement the semantics of the old checkalias function. When a device vnode first comes into existence, check to see if an anonymous vnode for the same device was created at boot time by bdevvp(). If so, adopt the bdevvp vnode rather than creating a new vnode for the device. This corrects a problem which caused the kernel to panic when taking a snapshot of the root filesystem. Change the calling convention of vn_write_suspend_wait() to be the same as vn_start_write(). Split out softdep_flushworklist() from softdep_flushfiles() so that it can be used to clear the work queue when suspending filesystem operations. Access to buffers becomes recursive so that snapshots can recursively traverse their indirect blocks using ffs_copyonwrite() when checking for the need for copy on write when flushing one of their own indirect blocks. This eliminates a deadlock between the syncer daemon and a process taking a snapshot. Ensure that softdep_process_worklist() can never block because of a snapshot being taken. This eliminates a problem with buffer starvation. Cleanup change in ffs_sync() which did not synchronously wait when MNT_WAIT was specified. The result was an unclean filesystem panic when doing forcible unmount with heavy filesystem I/O in progress. Return a zero'ed block when reading a block that was not in use at the time that a snapshot was taken. Normally, these blocks should never be read. However, the readahead code will occationally read them which can cause unexpected behavior. Clean up the debugging code that ensures that no blocks be written on a filesystem while it is suspended. Snapshots must explicitly label the blocks that they are writing during the suspension so that they do not cause a `write on suspended filesystem' panic. Reorganize ffs_copyonwrite() to eliminate a deadlock and also to prevent a race condition that would permit the same block to be copied twice. This change eliminates an unexpected soft updates inconsistency in fsck caused by the double allocation. Use bqrelse rather than brelse for buffers that will be needed soon again by the snapshot code. This improves snapshot performance.
2000-07-24 05:28:33 +00:00
bqrelse(ibp);
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
}
#ifdef DIAGNOSTIC
if (blkno == BLK_SNAP && bp->b_lblkno >= 0)
panic("ffs_copyonwrite: bad copy block");
#endif
This patch corrects the first round of panics and hangs reported with the new snapshot code. Update addaliasu to correctly implement the semantics of the old checkalias function. When a device vnode first comes into existence, check to see if an anonymous vnode for the same device was created at boot time by bdevvp(). If so, adopt the bdevvp vnode rather than creating a new vnode for the device. This corrects a problem which caused the kernel to panic when taking a snapshot of the root filesystem. Change the calling convention of vn_write_suspend_wait() to be the same as vn_start_write(). Split out softdep_flushworklist() from softdep_flushfiles() so that it can be used to clear the work queue when suspending filesystem operations. Access to buffers becomes recursive so that snapshots can recursively traverse their indirect blocks using ffs_copyonwrite() when checking for the need for copy on write when flushing one of their own indirect blocks. This eliminates a deadlock between the syncer daemon and a process taking a snapshot. Ensure that softdep_process_worklist() can never block because of a snapshot being taken. This eliminates a problem with buffer starvation. Cleanup change in ffs_sync() which did not synchronously wait when MNT_WAIT was specified. The result was an unclean filesystem panic when doing forcible unmount with heavy filesystem I/O in progress. Return a zero'ed block when reading a block that was not in use at the time that a snapshot was taken. Normally, these blocks should never be read. However, the readahead code will occationally read them which can cause unexpected behavior. Clean up the debugging code that ensures that no blocks be written on a filesystem while it is suspended. Snapshots must explicitly label the blocks that they are writing during the suspension so that they do not cause a `write on suspended filesystem' panic. Reorganize ffs_copyonwrite() to eliminate a deadlock and also to prevent a race condition that would permit the same block to be copied twice. This change eliminates an unexpected soft updates inconsistency in fsck caused by the double allocation. Use bqrelse rather than brelse for buffers that will be needed soon again by the snapshot code. This improves snapshot performance.
2000-07-24 05:28:33 +00:00
if (blkno != 0) {
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
VOP_UNLOCK(vp, 0, td);
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
continue;
This patch corrects the first round of panics and hangs reported with the new snapshot code. Update addaliasu to correctly implement the semantics of the old checkalias function. When a device vnode first comes into existence, check to see if an anonymous vnode for the same device was created at boot time by bdevvp(). If so, adopt the bdevvp vnode rather than creating a new vnode for the device. This corrects a problem which caused the kernel to panic when taking a snapshot of the root filesystem. Change the calling convention of vn_write_suspend_wait() to be the same as vn_start_write(). Split out softdep_flushworklist() from softdep_flushfiles() so that it can be used to clear the work queue when suspending filesystem operations. Access to buffers becomes recursive so that snapshots can recursively traverse their indirect blocks using ffs_copyonwrite() when checking for the need for copy on write when flushing one of their own indirect blocks. This eliminates a deadlock between the syncer daemon and a process taking a snapshot. Ensure that softdep_process_worklist() can never block because of a snapshot being taken. This eliminates a problem with buffer starvation. Cleanup change in ffs_sync() which did not synchronously wait when MNT_WAIT was specified. The result was an unclean filesystem panic when doing forcible unmount with heavy filesystem I/O in progress. Return a zero'ed block when reading a block that was not in use at the time that a snapshot was taken. Normally, these blocks should never be read. However, the readahead code will occationally read them which can cause unexpected behavior. Clean up the debugging code that ensures that no blocks be written on a filesystem while it is suspended. Snapshots must explicitly label the blocks that they are writing during the suspension so that they do not cause a `write on suspended filesystem' panic. Reorganize ffs_copyonwrite() to eliminate a deadlock and also to prevent a race condition that would permit the same block to be copied twice. This change eliminates an unexpected soft updates inconsistency in fsck caused by the double allocation. Use bqrelse rather than brelse for buffers that will be needed soon again by the snapshot code. This improves snapshot performance.
2000-07-24 05:28:33 +00:00
}
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
/*
* Allocate the block into which to do the copy. Note that this
* allocation will never require any additional allocations for
* the snapshot inode.
*/
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
td->td_proc->p_flag |= P_COWINPROGRESS;
VOP_BALLOC was never really a VOP in the first place, so convert it to UFS_BALLOC like the other "between UFS and FFS function interfaces".
2001-04-29 12:36:52 +00:00
error = UFS_BALLOC(vp, lblktosize(fs, (off_t)lbn),
This patch corrects the first round of panics and hangs reported with the new snapshot code. Update addaliasu to correctly implement the semantics of the old checkalias function. When a device vnode first comes into existence, check to see if an anonymous vnode for the same device was created at boot time by bdevvp(). If so, adopt the bdevvp vnode rather than creating a new vnode for the device. This corrects a problem which caused the kernel to panic when taking a snapshot of the root filesystem. Change the calling convention of vn_write_suspend_wait() to be the same as vn_start_write(). Split out softdep_flushworklist() from softdep_flushfiles() so that it can be used to clear the work queue when suspending filesystem operations. Access to buffers becomes recursive so that snapshots can recursively traverse their indirect blocks using ffs_copyonwrite() when checking for the need for copy on write when flushing one of their own indirect blocks. This eliminates a deadlock between the syncer daemon and a process taking a snapshot. Ensure that softdep_process_worklist() can never block because of a snapshot being taken. This eliminates a problem with buffer starvation. Cleanup change in ffs_sync() which did not synchronously wait when MNT_WAIT was specified. The result was an unclean filesystem panic when doing forcible unmount with heavy filesystem I/O in progress. Return a zero'ed block when reading a block that was not in use at the time that a snapshot was taken. Normally, these blocks should never be read. However, the readahead code will occationally read them which can cause unexpected behavior. Clean up the debugging code that ensures that no blocks be written on a filesystem while it is suspended. Snapshots must explicitly label the blocks that they are writing during the suspension so that they do not cause a `write on suspended filesystem' panic. Reorganize ffs_copyonwrite() to eliminate a deadlock and also to prevent a race condition that would permit the same block to be copied twice. This change eliminates an unexpected soft updates inconsistency in fsck caused by the double allocation. Use bqrelse rather than brelse for buffers that will be needed soon again by the snapshot code. This improves snapshot performance.
2000-07-24 05:28:33 +00:00
fs->fs_bsize, KERNCRED, B_NOWAIT, &cbp);
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
td->td_proc->p_flag &= ~P_COWINPROGRESS;
This patch corrects the first round of panics and hangs reported with the new snapshot code. Update addaliasu to correctly implement the semantics of the old checkalias function. When a device vnode first comes into existence, check to see if an anonymous vnode for the same device was created at boot time by bdevvp(). If so, adopt the bdevvp vnode rather than creating a new vnode for the device. This corrects a problem which caused the kernel to panic when taking a snapshot of the root filesystem. Change the calling convention of vn_write_suspend_wait() to be the same as vn_start_write(). Split out softdep_flushworklist() from softdep_flushfiles() so that it can be used to clear the work queue when suspending filesystem operations. Access to buffers becomes recursive so that snapshots can recursively traverse their indirect blocks using ffs_copyonwrite() when checking for the need for copy on write when flushing one of their own indirect blocks. This eliminates a deadlock between the syncer daemon and a process taking a snapshot. Ensure that softdep_process_worklist() can never block because of a snapshot being taken. This eliminates a problem with buffer starvation. Cleanup change in ffs_sync() which did not synchronously wait when MNT_WAIT was specified. The result was an unclean filesystem panic when doing forcible unmount with heavy filesystem I/O in progress. Return a zero'ed block when reading a block that was not in use at the time that a snapshot was taken. Normally, these blocks should never be read. However, the readahead code will occationally read them which can cause unexpected behavior. Clean up the debugging code that ensures that no blocks be written on a filesystem while it is suspended. Snapshots must explicitly label the blocks that they are writing during the suspension so that they do not cause a `write on suspended filesystem' panic. Reorganize ffs_copyonwrite() to eliminate a deadlock and also to prevent a race condition that would permit the same block to be copied twice. This change eliminates an unexpected soft updates inconsistency in fsck caused by the double allocation. Use bqrelse rather than brelse for buffers that will be needed soon again by the snapshot code. This improves snapshot performance.
2000-07-24 05:28:33 +00:00
if (error) {
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
VOP_UNLOCK(vp, 0, td);
This patch corrects the first round of panics and hangs reported with the new snapshot code. Update addaliasu to correctly implement the semantics of the old checkalias function. When a device vnode first comes into existence, check to see if an anonymous vnode for the same device was created at boot time by bdevvp(). If so, adopt the bdevvp vnode rather than creating a new vnode for the device. This corrects a problem which caused the kernel to panic when taking a snapshot of the root filesystem. Change the calling convention of vn_write_suspend_wait() to be the same as vn_start_write(). Split out softdep_flushworklist() from softdep_flushfiles() so that it can be used to clear the work queue when suspending filesystem operations. Access to buffers becomes recursive so that snapshots can recursively traverse their indirect blocks using ffs_copyonwrite() when checking for the need for copy on write when flushing one of their own indirect blocks. This eliminates a deadlock between the syncer daemon and a process taking a snapshot. Ensure that softdep_process_worklist() can never block because of a snapshot being taken. This eliminates a problem with buffer starvation. Cleanup change in ffs_sync() which did not synchronously wait when MNT_WAIT was specified. The result was an unclean filesystem panic when doing forcible unmount with heavy filesystem I/O in progress. Return a zero'ed block when reading a block that was not in use at the time that a snapshot was taken. Normally, these blocks should never be read. However, the readahead code will occationally read them which can cause unexpected behavior. Clean up the debugging code that ensures that no blocks be written on a filesystem while it is suspended. Snapshots must explicitly label the blocks that they are writing during the suspension so that they do not cause a `write on suspended filesystem' panic. Reorganize ffs_copyonwrite() to eliminate a deadlock and also to prevent a race condition that would permit the same block to be copied twice. This change eliminates an unexpected soft updates inconsistency in fsck caused by the double allocation. Use bqrelse rather than brelse for buffers that will be needed soon again by the snapshot code. This improves snapshot performance.
2000-07-24 05:28:33 +00:00
if (error != EWOULDBLOCK)
break;
In a threaded world, differnt priorirites become properties of different entities. Make it so. Reviewed by: jhb@freebsd.org (john baldwin)
2002-02-11 20:37:54 +00:00
tsleep(vp, td->td_ksegrp->kg_user_pri, "nap", 1);
This patch corrects the first round of panics and hangs reported with the new snapshot code. Update addaliasu to correctly implement the semantics of the old checkalias function. When a device vnode first comes into existence, check to see if an anonymous vnode for the same device was created at boot time by bdevvp(). If so, adopt the bdevvp vnode rather than creating a new vnode for the device. This corrects a problem which caused the kernel to panic when taking a snapshot of the root filesystem. Change the calling convention of vn_write_suspend_wait() to be the same as vn_start_write(). Split out softdep_flushworklist() from softdep_flushfiles() so that it can be used to clear the work queue when suspending filesystem operations. Access to buffers becomes recursive so that snapshots can recursively traverse their indirect blocks using ffs_copyonwrite() when checking for the need for copy on write when flushing one of their own indirect blocks. This eliminates a deadlock between the syncer daemon and a process taking a snapshot. Ensure that softdep_process_worklist() can never block because of a snapshot being taken. This eliminates a problem with buffer starvation. Cleanup change in ffs_sync() which did not synchronously wait when MNT_WAIT was specified. The result was an unclean filesystem panic when doing forcible unmount with heavy filesystem I/O in progress. Return a zero'ed block when reading a block that was not in use at the time that a snapshot was taken. Normally, these blocks should never be read. However, the readahead code will occationally read them which can cause unexpected behavior. Clean up the debugging code that ensures that no blocks be written on a filesystem while it is suspended. Snapshots must explicitly label the blocks that they are writing during the suspension so that they do not cause a `write on suspended filesystem' panic. Reorganize ffs_copyonwrite() to eliminate a deadlock and also to prevent a race condition that would permit the same block to be copied twice. This change eliminates an unexpected soft updates inconsistency in fsck caused by the double allocation. Use bqrelse rather than brelse for buffers that will be needed soon again by the snapshot code. This improves snapshot performance.
2000-07-24 05:28:33 +00:00
goto retry;
}
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
#ifdef DEBUG
if (snapdebug) {
printf("Copyonwrite: snapino %d lbn %d for ",
ip->i_number, lbn);
Fixes to track snapshot copy-on-write checking in the specinfo structure rather than assuming that the device vnode would reside in the FFS filesystem (which is obviously a broken assumption with the device filesystem).
2001-03-07 07:09:55 +00:00
if (bp->b_vp == devvp)
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
printf("fs metadata");
else
printf("inum %d", VTOI(bp->b_vp)->i_number);
Fixed some printf format errors (hopefully all of the remaining daddr64_t ones for GENERIC, and all others on the same line as those). Reformat the printfs if necessary to avoid new long lones or old format printf errors.
2002-03-19 04:09:21 +00:00
printf(" lblkno %lld to blkno %lld\n",
(long long)bp->b_lblkno, (long long)cbp->b_blkno);
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
}
#endif
/*
* If we have already read the old block contents, then
When closing the last reference to an unlinked file, it is freed by the inactive routine. Because the freeing causes the filesystem to be modified, the close must be held up during periods when the filesystem is suspended. For snapshots to be consistent across crashes, they must write blocks that they copy and claim those written blocks in their on-disk block pointers before the old blocks that they referenced can be allowed to be written. Close a loophole that allowed unwritten blocks to be skipped when doing ffs_sync with a request to wait for all I/O activity to be completed.
2001-04-25 08:11:18 +00:00
* simply copy them to the new block. Note that we need
* to synchronously write snapshots that have not been
* unlinked, and hence will be visible after a crash,
* to ensure their integrity.
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
*/
if (savedcbp != 0) {
bcopy(savedcbp->b_data, cbp->b_data, fs->fs_bsize);
bawrite(cbp);
Further fixes for deadlock in the presence of multiple snapshots. There are still more to find, but this fix should cover the common cases that folks are hitting.
2001-05-14 17:16:49 +00:00
if (dopersistence && ip->i_effnlink > 0)
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
(void) VOP_FSYNC(vp, KERNCRED, MNT_WAIT, td);
VOP_UNLOCK(vp, 0, td);
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
continue;
}
/*
* Otherwise, read the old block contents into the buffer.
*/
When closing the last reference to an unlinked file, it is freed by the inactive routine. Because the freeing causes the filesystem to be modified, the close must be held up during periods when the filesystem is suspended. For snapshots to be consistent across crashes, they must write blocks that they copy and claim those written blocks in their on-disk block pointers before the old blocks that they referenced can be allowed to be written. Close a loophole that allowed unwritten blocks to be skipped when doing ffs_sync with a request to wait for all I/O activity to be completed.
2001-04-25 08:11:18 +00:00
if ((error = readblock(cbp, lbn)) != 0) {
bzero(cbp->b_data, fs->fs_bsize);
bawrite(cbp);
Further fixes for deadlock in the presence of multiple snapshots. There are still more to find, but this fix should cover the common cases that folks are hitting.
2001-05-14 17:16:49 +00:00
if (dopersistence && ip->i_effnlink > 0)
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
(void) VOP_FSYNC(vp, KERNCRED, MNT_WAIT, td);
VOP_UNLOCK(vp, 0, td);
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
break;
When closing the last reference to an unlinked file, it is freed by the inactive routine. Because the freeing causes the filesystem to be modified, the close must be held up during periods when the filesystem is suspended. For snapshots to be consistent across crashes, they must write blocks that they copy and claim those written blocks in their on-disk block pointers before the old blocks that they referenced can be allowed to be written. Close a loophole that allowed unwritten blocks to be skipped when doing ffs_sync with a request to wait for all I/O activity to be completed.
2001-04-25 08:11:18 +00:00
}
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
savedcbp = cbp;
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
VOP_UNLOCK(vp, 0, td);
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
}
When closing the last reference to an unlinked file, it is freed by the inactive routine. Because the freeing causes the filesystem to be modified, the close must be held up during periods when the filesystem is suspended. For snapshots to be consistent across crashes, they must write blocks that they copy and claim those written blocks in their on-disk block pointers before the old blocks that they referenced can be allowed to be written. Close a loophole that allowed unwritten blocks to be skipped when doing ffs_sync with a request to wait for all I/O activity to be completed.
2001-04-25 08:11:18 +00:00
/*
* Note that we need to synchronously write snapshots that
* have not been unlinked, and hence will be visible after
* a crash, to ensure their integrity.
*/
if (savedcbp) {
vp = savedcbp->b_vp;
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
bawrite(savedcbp);
Further fixes for deadlock in the presence of multiple snapshots. There are still more to find, but this fix should cover the common cases that folks are hitting.
2001-05-14 17:16:49 +00:00
if (dopersistence && VTOI(vp)->i_effnlink > 0) {
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
(void) VOP_FSYNC(vp, KERNCRED, MNT_WAIT, td);
VOP_UNLOCK(vp, 0, td);
Further fixes for deadlock in the presence of multiple snapshots. There are still more to find, but this fix should cover the common cases that folks are hitting.
2001-05-14 17:16:49 +00:00
}
When closing the last reference to an unlinked file, it is freed by the inactive routine. Because the freeing causes the filesystem to be modified, the close must be held up during periods when the filesystem is suspended. For snapshots to be consistent across crashes, they must write blocks that they copy and claim those written blocks in their on-disk block pointers before the old blocks that they referenced can be allowed to be written. Close a loophole that allowed unwritten blocks to be skipped when doing ffs_sync with a request to wait for all I/O activity to be completed.
2001-04-25 08:11:18 +00:00
}
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
return (error);
}
/*
* Read the specified block into the given buffer.
* Much of this boiler-plate comes from bwrite().
*/
static int
readblock(bp, lbn)
struct buf *bp;
daddr_t lbn;
{
struct uio auio;
struct iovec aiov;
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
struct thread *td = curthread;
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
struct inode *ip = VTOI(bp->b_vp);
aiov.iov_base = bp->b_data;
aiov.iov_len = bp->b_bcount;
auio.uio_iov = &aiov;
auio.uio_iovcnt = 1;
auio.uio_offset = dbtob(fsbtodb(ip->i_fs, blkstofrags(ip->i_fs, lbn)));
auio.uio_resid = bp->b_bcount;
auio.uio_rw = UIO_READ;
auio.uio_segflg = UIO_SYSSPACE;
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
auio.uio_td = td;
Add snapshots to the fast filesystem. Most of the changes support the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
2000-07-11 22:07:57 +00:00
return (physio(ip->i_devvp->v_rdev, &auio, 0));
}
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