Commit Graph

469 Commits

Author SHA1 Message Date
John Baldwin
eb46fac565 - Fix some minor whitespace nits.
- Move the SPECIAL_FLAG #define up next to the NOHOLDER #define and fix a
  little nit that caused it to be defined as -(sizeof (struct thread) + 1)
  instead of -2.
2001-09-27 21:04:13 +00:00
Julian Elischer
b40ce4165d 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
Ian Dowse
4691e9ead0 The "dirpref" directory layout preference improvements make use of
an array "fs_contigdirs[]" to avoid too many directories getting
created in each cylinder group. The memory required for this and
two other arrays (fs_csp[] and fs_maxcluster[]) is allocated with
a single malloc() call, and divided up afterwards.  However, the
'space' pointer is not advanced correctly, so fs_contigdirs and
fs_maxcluster end up pointing to the same address.

Add the missing code to advance the 'space' pointer, and remove
an unnecessary update of the pointer that follows.

This is likely to fix the "ffs_clusteralloc: map mismatch" panics
that have been reported recently.

Submitted by:		Luke Mewburn <lukem@wasabisystems.com>
2001-09-09 23:48:28 +00:00
Robert Watson
7df97b6117 o At some point, unmounting a non-EA file system with EA's compiled
in got a bit broken, when ufs_extattr_stop() was called and failed,
  ufs_extattr_destroy() would panic.  This makes the call to destroy()
  conditional on the success of stop().

Submitted by:		Christian Carstensen <cc@devcon.net>
Obtained from:	TrustedBSD Project
2001-09-01 20:11:05 +00:00
Peter Wemm
815d14ddab Use a fixed type for times in on-disk structures for ufs rather than
something that could potentially change like time_t.
2001-07-16 00:55:27 +00:00
John Baldwin
ed87274d16 Fix more mntvnode and vnode interlock order reversals. 2001-06-28 22:21:33 +00:00
John Baldwin
49d2d9f4a4 - Fix a mntvnode and vnode interlock reversal.
- Protect the mnt_vnode list with the mntvnode lock.
- Use queue(9) macros.
2001-06-28 04:12:56 +00:00
Peter Wemm
78236790cd Fix warning:
1973: warning: int format, long int arg (arg 5)
2001-06-15 07:44:39 +00:00
Kirk McKusick
eb87cd754f Build on the change in revision 1.98 by Tor.Egge@fast.no.
The symptom being treated in 1.98 was to avoid freeing a
pagedep dependency if there was still a newdirblk dependency
referencing it. That change is correct and no longer prints
a warning message when it occurs. The other part of revision
1.98 was to panic when a newdirblk dependency was encountered
during a file truncation. This fix removes that panic and
replaces it with code to find and delete the newdirblk
dependency so that the truncation can succeed.
2001-06-13 23:13:13 +00:00
David E. O'Brien
1239674238 There seems to be a problem that the order of disk write operation being
incorrect due to a missing check for some dependency.  This change
avoids the freelist corruption (but not the temporarily inconsistent
state of the file system).

A message is printed as a reminder of the under lying problem when a
pagedep structure is not freed due to the NEWBLOCK flag being set.

Submitted by:	Tor.Egge@fast.no
2001-06-05 01:49:37 +00:00
John Baldwin
1c11b01562 Revert the previous commit in favor of the fix in rev 1.42 of
ufs/ffs/ffs_extern.h instead.

Requested by:	bde
2001-05-30 23:09:19 +00:00
John Baldwin
55d132317c Forward declare struct cg to quiet a warning.
Submitted by:	bde
2001-05-30 23:08:40 +00:00
John Baldwin
59718ee556 Include <ufs/ffs/fs.h> to get the definition of struct cg to quiet a
warning.
2001-05-29 23:53:16 +00:00
Poul-Henning Kamp
c7a3e2379c Remove last vestiges of MFS. 2001-05-29 21:21:53 +00:00
Kirk McKusick
57042c7f72 Update softdep_setup_directory_add prototype to reflect changes in
actual function.

Obtained from:	Jim Bloom <bloom@jbloom.jbloom.org>
2001-05-20 15:59:55 +00:00
Kirk McKusick
dc01275be9 Must ensure that all the entries on the pd_pendinghd list have been
committed to disk before clearing them. More specifically, when
free_newdirblk is called, we know that the inode claims the new
directory block. However, if the associated pagedep is still linked
onto the directory buffer dependency chain, then some of the entries
on the pd_pendinghd list may not be committed to disk yet. In this
case, we will simply note that the inode claims the block and let
the pd_pendinghd list be processed when the pagedep is next written.
If the pagedep is no longer on the buffer dependency chain, then
all the entries on the pd_pending list are committed to disk and
we can free them in free_newdirblk. This corrects a window of
vulnerability introduced in the code added in version 1.95.
2001-05-19 19:24:26 +00:00
Kirk McKusick
9f5192ff71 Must be a bit less aggressive about freeing pagedep structures.
Obtained from:	Robert Watson <rwatson@FreeBSD.org> and
		Matthew Jacob <mjacob@feral.com>
2001-05-18 22:16:28 +00:00
Kirk McKusick
24a83a4b3f When a new block is allocated to a directory, an fsync of a file
whose name is within that block must ensure not only that the block
containing the file name has been written, but also that the on-disk
directory inode references that block. When a new directory block
is created, we allocate a newdirblk structure which is linked to
the associated allocdirect (on its ad_newdirblk list). When the
allocdirect has been satisfied, the newdirblk structure is moved
to the inodedep id_bufwait list of its directory to await the inode
being written.  When the inode is written, the directory entries
are fully committed and can be deleted from their pagedep->id_pendinghd
and inodedep->id_pendinghd lists.
2001-05-17 07:24:03 +00:00
Ian Dowse
0864ef1e8a Change the second argument of vflush() to an integer that specifies
the number of references on the filesystem root vnode to be both
expected and released. Many filesystems hold an extra reference on
the filesystem root vnode, which must be accounted for when
determining if the filesystem is busy and then released if it isn't
busy. The old `skipvp' approach required individual filesystem
xxx_unmount functions to re-implement much of vflush()'s logic to
deal with the root vnode.

All 9 filesystems that hold an extra reference on the root vnode
got the logic wrong in the case of forced unmounts, so `umount -f'
would always fail if there were any extra root vnode references.
Fix this issue centrally in vflush(), now that we can.

This commit also fixes a vnode reference leak in devfs, which could
result in idle devfs filesystems that refuse to unmount.

Reviewed by:	phk, bp
2001-05-16 18:04:37 +00:00
Kirk McKusick
7389126d9a 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
Kirk McKusick
9b35c30cf7 Remove yet another deadlock case. 2001-05-11 07:12:03 +00:00
Kirk McKusick
9ccb939ef0 When running with soft updates, track the number of blocks and files
that are committed to being freed and reflect these blocks in the
counts returned by statfs (and thus also by the `df' command). This
change allows programs such as those that do news expiration to
know when to stop if they are trying to create a certain percentage
of free space. Note that this change does not solve the much harder
problem of making this to-be-freed space available to applications
that want it (thus on a nearly full filesystem, you may still
encounter out-of-space conditions even though the free space will
show up eventually). Hopefully this harder problem will be the
subject of a future enhancement.
2001-05-08 07:42:20 +00:00
Kirk McKusick
27b047acf0 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
Kirk McKusick
0c6fbff0a5 When syncing out snapshot metadata, we must temporarily allow recursive
buffer locking so as to avoid locking against ourselves if we need to
write filesystem metadata.
2001-05-08 07:13:00 +00:00
Kirk McKusick
23371b2f22 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
Poul-Henning Kamp
3c7a8027cb Remove blatantly pointless call to VOP_BMAP().
Use ufs_bmaparray() rather than VOP_BMAP() on our own vnodes.
2001-05-01 09:12:31 +00:00
Poul-Henning Kamp
a62615e59b Implement vop_std{get|put}pages() and add them to the default vop[].
Un-copy&paste all the VOP_{GET|PUT}PAGES() functions which do nothing but
the default.
2001-05-01 08:34:45 +00:00
Poul-Henning Kamp
855aa097af 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
Poul-Henning Kamp
0c25dbeb17 Remove faint traces of non-existant ffs_bmap(). 2001-04-29 10:23:32 +00:00
Greg Lehey
60fb0ce365 Revert consequences of changes to mount.h, part 2.
Requested by:	bde
2001-04-29 02:45:39 +00:00
Kirk McKusick
c9509f5865 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
Kirk McKusick
112f737245 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
Poul-Henning Kamp
a13234bb35 Move the netexport structure from the fs-specific mountstructure
to struct mount.

This makes the "struct netexport *" paramter to the vfs_export
and vfs_checkexport interface unneeded.

Consequently that all non-stacking filesystems can use
vfs_stdcheckexp().

At the same time, make it a pointer to a struct netexport
in struct mount, so that we can remove the bogus AF_MAX
and #include <net/radix.h> from <sys/mount.h>
2001-04-25 07:07:52 +00:00
Ian Dowse
5d69bac493 Pre-dirpref versions of fsck may zero out the new superblock fields
fs_contigdirs, fs_avgfilesize and fs_avgfpdir. This could cause
panics if these fields were zeroed while a filesystem was mounted
read-only, and then remounted read-write.

Add code to ffs_reload() which copies the fs_contigdirs pointer
from the previous superblock, and reinitialises fs_avgf* if necessary.

Reviewed by:	mckusick
2001-04-24 00:37:16 +00:00
Greg Lehey
d98dc34f52 Correct #includes to work with fixed sys/mount.h. 2001-04-23 09:05:15 +00:00
Kirk McKusick
5819ab3f12 Add debugging option to always read/write cylinder groups as full
sized blocks. To enable this option, use: `sysctl -w debug.bigcgs=1'.
Add debugging option to disable background writes of cylinder
groups. To enable this option, use: `sysctl -w debug.dobkgrdwrite=0'.
These debugging options should be tried on systems that are panicing
with corrupted cylinder group maps to see if it makes the problem
go away. The set of panics in question are:

	ffs_clusteralloc: map mismatch
	ffs_nodealloccg: map corrupted
	ffs_nodealloccg: block not in map
	ffs_alloccg: map corrupted
	ffs_alloccg: block not in map
	ffs_alloccgblk: cyl groups corrupted
	ffs_alloccgblk: can't find blk in cyl
	ffs_checkblk: partially free fragment

The following panics are less likely to be related to this problem,
but might be helped by these debugging options:

	ffs_valloc: dup alloc
	ffs_blkfree: freeing free block
	ffs_blkfree: freeing free frag
	ffs_vfree: freeing free inode

If you try these options, please report whether they helped reduce your
bitmap corruption panics to Kirk McKusick at <mckusick@mckusick.com>
and to Matt Dillon <dillon@earth.backplane.com>.
2001-04-17 05:37:51 +00:00
Kirk McKusick
f0f3f19f05 Background fsck sysctl operations must use vn_start_write and
vn_finished_write so that they do not attempt to modify a
suspended filesystem.
2001-04-17 05:06:37 +00:00
Kirk McKusick
74046077a7 Update to describe use of mdconfig instead of deprecated vnconfig.
Submitted by:	Steve Ames <steve@virtual-voodoo.com>
2001-04-14 18:32:09 +00:00
Kirk McKusick
1a6a661032 This checkin adds support in ufs/ffs for the FS_NEEDSFSCK flag.
It is described in ufs/ffs/fs.h as follows:

/*
 * Filesystem flags.
 *
 * Note that the FS_NEEDSFSCK flag is set and cleared only by the
 * fsck utility. It is set when background fsck finds an unexpected
 * inconsistency which requires a traditional foreground fsck to be
 * run. Such inconsistencies should only be found after an uncorrectable
 * disk error. A foreground fsck will clear the FS_NEEDSFSCK flag when
 * it has successfully cleaned up the filesystem. The kernel uses this
 * flag to enforce that inconsistent filesystems be mounted read-only.
 */
#define FS_UNCLEAN    0x01	/* filesystem not clean at mount */
#define FS_DOSOFTDEP  0x02	/* filesystem using soft dependencies */
#define FS_NEEDSFSCK  0x04	/* filesystem needs sync fsck before mount */
2001-04-14 05:26:28 +00:00
Kirk McKusick
a61ab64ac4 Directory layout preference improvements from Grigoriy Orlov <gluk@ptci.ru>.
His description of the problem and solution follow. My own tests show
speedups on typical filesystem intensive workloads of 5% to 12% which
is very impressive considering the small amount of code change involved.

------

  One day I noticed that some file operations run much faster on
small file systems then on big ones. I've looked at the ffs
algorithms, thought about them, and redesigned the dirpref algorithm.

  First I want to describe the results of my tests. These results are old
and I have improved the algorithm after these tests were done. Nevertheless
they show how big the perfomance speedup may be. I have done two file/directory
intensive tests on a two OpenBSD systems with old and new dirpref algorithm.
The first test is "tar -xzf ports.tar.gz", the second is "rm -rf ports".
The ports.tar.gz file is the ports collection from the OpenBSD 2.8 release.
It contains 6596 directories and 13868 files. The test systems are:

1. Celeron-450, 128Mb, two IDE drives, the system at wd0, file system for
   test is at wd1. Size of test file system is 8 Gb, number of cg=991,
   size of cg is 8m, block size = 8k, fragment size = 1k OpenBSD-current
   from Dec 2000 with BUFCACHEPERCENT=35

2. PIII-600, 128Mb, two IBM DTLA-307045 IDE drives at i815e, the system
   at wd0, file system for test is at wd1. Size of test file system is 40 Gb,
   number of cg=5324, size of cg is 8m, block size = 8k, fragment size = 1k
   OpenBSD-current from Dec 2000 with BUFCACHEPERCENT=50

You can get more info about the test systems and methods at:
http://www.ptci.ru/gluk/dirpref/old/dirpref.html

                              Test Results

             tar -xzf ports.tar.gz               rm -rf ports
  mode  old dirpref new dirpref speedup old dirprefnew dirpref speedup
                             First system
 normal     667         472      1.41       477        331       1.44
 async      285         144      1.98       130         14       9.29
 sync       768         616      1.25       477        334       1.43
 softdep    413         252      1.64       241         38       6.34
                             Second system
 normal     329         81       4.06       263.5       93.5     2.81
 async      302         25.7    11.75       112          2.26   49.56
 sync       281         57.0     4.93       263         90.5     2.9
 softdep    341         40.6     8.4        284          4.76   59.66

"old dirpref" and "new dirpref" columns give a test time in seconds.
speedup - speed increasement in times, ie. old dirpref / new dirpref.

------

Algorithm description

The old dirpref algorithm is described in comments:

/*
 * Find a cylinder to place a directory.
 *
 * The policy implemented by this algorithm is to select from
 * among those cylinder groups with above the average number of
 * free inodes, the one with the smallest number of directories.
 */

A new directory is allocated in a different cylinder groups than its
parent directory resulting in a directory tree that is spreaded across
all the cylinder groups. This spreading out results in a non-optimal
access to the directories and files. When we have a small filesystem
it is not a problem but when the filesystem is big then perfomance
degradation becomes very apparent.

What I mean by a big file system ?

  1. A big filesystem is a filesystem which occupy 20-30 or more percent
     of total drive space, i.e. first and last cylinder are physically
     located relatively far from each other.
  2. It has a relatively large number of cylinder groups, for example
     more cylinder groups than 50% of the buffers in the buffer cache.

The first results in long access times, while the second results in
many buffers being used by metadata operations. Such operations use
cylinder group blocks and on-disk inode blocks. The cylinder group
block (fs->fs_cblkno) contains struct cg, inode and block bit maps.
It is 2k in size for the default filesystem parameters. If new and
parent directories are located in different cylinder groups then the
system performs more input/output operations and uses more buffers.
On filesystems with many cylinder groups, lots of cache buffers are
used for metadata operations.

My solution for this problem is very simple. I allocate many directories
in one cylinder group. I also do some things, so that the new allocation
method does not cause excessive fragmentation and all directory inodes
will not be located at a location far from its file's inodes and data.
The algorithm is:
/*
 * Find a cylinder group to place a directory.
 *
 * The policy implemented by this algorithm is to allocate a
 * directory inode in the same cylinder group as its parent
 * directory, but also to reserve space for its files inodes
 * and data. Restrict the number of directories which may be
 * allocated one after another in the same cylinder group
 * without intervening allocation of files.
 *
 * If we allocate a first level directory then force allocation
 * in another cylinder group.
 */

  My early versions of dirpref give me a good results for a wide range of
file operations and different filesystem capacities except one case:
those applications that create their entire directory structure first
and only later fill this structure with files.

  My solution for such and similar cases is to limit a number of
directories which may be created one after another in the same cylinder
group without intervening file creations. For this purpose, I allocate
an array of counters at mount time. This array is linked to the superblock
fs->fs_contigdirs[cg]. Each time a directory is created the counter
increases and each time a file is created the counter decreases. A 60Gb
filesystem with 8mb/cg requires 10kb of memory for the counters array.

  The maxcontigdirs is a maximum number of directories which may be created
without an intervening file creation. I found in my tests that the best
performance occurs when I restrict the number of directories in one cylinder
group such that all its files may be located in the same cylinder group.
There may be some deterioration in performance if all the file inodes
are in the same cylinder group as its containing directory, but their
data partially resides in a different cylinder group. The maxcontigdirs
value is calculated to try to prevent this condition. Since there is
no way to know how many files and directories will be allocated later
I added two optimization parameters in superblock/tunefs. They are:

        int32_t  fs_avgfilesize;   /* expected average file size */
        int32_t  fs_avgfpdir;      /* expected # of files per directory */

These parameters have reasonable defaults but may be tweeked for special
uses of a filesystem. They are only necessary in rare cases like better
tuning a filesystem being used to store a squid cache.

I have been using this algorithm for about 3 months. I have done
a lot of testing on filesystems with different capacities, average
filesize, average number of files per directory, and so on. I think
this algorithm has no negative impact on filesystem perfomance. It
works better than the default one in all cases. The new dirpref
will greatly improve untarring/removing/coping of big directories,
decrease load on cvs servers and much more. The new dirpref doesn't
speedup a compilation process, but also doesn't slow it down.

Obtained from:	Grigoriy Orlov <gluk@ptci.ru>
2001-04-10 08:38:59 +00:00
Jeroen Ruigrok van der Werven
5d0b660f2a Fix typo ); -> , 2001-03-24 15:25:04 +00:00
Kirk McKusick
fca26df055 Check that background fsck operation is being done on a ufs filesystem.
Obtained from:	Robert Watson <rwatson@FreeBSD.org>
2001-03-23 20:58:25 +00:00
Kirk McKusick
812b1d416c Add kernel support for running fsck on active filesystems. 2001-03-21 04:09:01 +00:00
Kirk McKusick
31c6ce0aed 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
Kirk McKusick
7e72e9918a Report the correct inode number when panicing with freeing free inode.
Report the correct block number when panicing with freeing free block.
2001-03-21 04:01:02 +00:00
Robert Watson
516081f288 o Change options FFS_EXTATTR and options FFS_EXTATTR_AUTOSTART to
options UFS_EXTATTR and UFS_EXTATTR_AUTOSTART respectively.  This change
  reflects the fact that our EA support is implemented entirely at the
  UFS layer (modulo FFS start/stop/autostart hooks for mount and unmount
  events).  This also better reflects the fact that [shortly] MFS will also
  support EAs, as well as possibly IFS.

o Consumers of the EA support in FFS are reminded that as a result, they
  must change kernel config files to reflect the new option names.

Obtained from:	TrustedBSD Project
2001-03-19 04:35:40 +00:00
Robert Watson
f5161237ad o Implement "options FFS_EXTATTR_AUTOSTART", which depends on
"options FFS_EXTATTR".  When extended attribute auto-starting
  is enabled, FFS will scan the .attribute directory off of the
  root of each file system, as it is mounted.  If .attribute
  exists, EA support will be started for the file system.  If
  there are files in the directory, FFS will attempt to start
  them as attribute backing files for attributes baring the same
  name.  All attributes are started before access to the file
  system is permitted, so this permits race-free enabling of
  attributes.  For attributes backing support for security
  features, such as ACLs, MAC, Capabilities, this is vital, as
  it prevents the file system attributes from getting out of
  sync as a result of file system operations between mount-time
  and the enabling of the extended attribute.  The userland
  extattrctl tool will still function exactly as previously.
  Files must be placed directly in .attribute, which must be
  directly off of the file system root: symbolic links are
  not permitted.  FFS_EXTATTR will continue to be able
  to function without FFS_EXTATTR_AUTOSTART for sites that do not
  want/require auto-starting.  If you're using the UFS_ACL code
  available from www.TrustedBSD.org, using FFS_EXTATTR_AUTOSTART
  is recommended.

o This support is implemented by adding an invocation of
  ufs_extattr_autostart() to ffs_mountfs().  In addition,
  several new supporting calls are introduced in
  ufs_extattr.c:

    ufs_extattr_autostart(): start EAs on the specified mount
    ufs_extattr_lookup(): given a directory and filename,
                          return the vnode for the file.
    ufs_extattr_enable_with_open(): invoke ufs_extattr_enable()
                          after doing the equililent of vn_open()
                          on the passed file.
    ufs_extattr_iterate_directory(): iterate over a directory,
                          invoking ufs_extattr_lookup() and
                          ufs_extattr_enable_with_open() on each
                          entry.

o This feature is not widely tested, and therefore may contain
  bugs, caution is advised.  Several changes are in the pipeline
  for this feature, including breaking out of EA namespaces into
  subdirectories of .attribute (this is waiting on the updated
  EA API), as well as a per-filesystem flag indicating whether
  or not EAs should be auto-started.  This is required because
  administrators may not want .attribute auto-started on all
  file systems, especially if non-administrators have write access
  to the root of a file system.

Obtained from:	TrustedBSD Project
2001-03-14 05:32:31 +00:00
Kirk McKusick
589c7af992 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
Kirk McKusick
8775e64a5d Free lock before returning from process_worklist_item.
Obtained from:	Constantine Sapuntzakis <csapuntz@stanford.edu>
2001-03-01 21:43:46 +00:00
Adrian Chadd
f3a90da995 Reviewed by: jlemon
An initial tidyup of the mount() syscall and VFS mount code.

This code replaces the earlier work done by jlemon in an attempt to
make linux_mount() work.

* the guts of the mount work has been moved into vfs_mount().

* move `type', `path' and `flags' from being userland variables into being
  kernel variables in vfs_mount(). `data' remains a pointer into
  userspace.

* Attempt to verify the `type' and `path' strings passed to vfs_mount()
  aren't too long.

* rework mount() and linux_mount() to take the userland parameters
  (besides data, as mentioned) and pass kernel variables to vfs_mount().
  (linux_mount() already did this, I've just tidied it up a little more.)

* remove the copyin*() stuff for `path'. `data' still requires copyin*()
  since its a pointer into userland.

* set `mount->mnt_statf_mntonname' in vfs_mount() rather than in each
  filesystem.  This variable is generally initialised with `path', and
  each filesystem can override it if they want to.

* NOTE: f_mntonname is intiailised with "/" in the case of a root mount.
2001-03-01 21:00:17 +00:00
Kirk McKusick
a5a94e3936 Free lock before calling panic so that subsequent attempt to write out
buffers does not re-panic with `locking against myself'. This change
should not affect normal operations of soft updates in any way.
2001-02-23 09:01:31 +00:00
Kirk McKusick
cc686e21c0 When cleaning up excess inode dependencies, check for being done.
Reviewed by:	Jan Koum <jkb@yahoo-inc.com>
2001-02-22 10:17:57 +00:00
Kirk McKusick
2cf5d587a9 This patch corrects two problems with the rate limiting code
that was introduced in revision 1.80. The problem manifested
itself with a `locking against myself' panic and could also
result in soft updates inconsistences associated with inodedeps.
The two problems are:

1) One of the background operations could manipulate the bitmap
while holding it locked with intent to create. This held lock
results in a `locking against myself' panic, when the background
processing that we have been coopted to do tries to lock the bitmap
which we are already holding locked. To understand how to fix this
problem, first, observe that we can do the background cleanups in
inodedep_lookup only when allocating inodedeps (DEPALLOC is set in
the call to inodedep_lookup). Second observe that calls to
inodedep_lookup with DEPALLOC set can only happen from the following
calls into the softdep code:

        softdep_setup_inomapdep
        softdep_setup_allocdirect
        softdep_setup_remove
        softdep_setup_freeblocks
        softdep_setup_directory_change
        softdep_setup_directory_add
        softdep_change_linkcnt

Only the first two of these can come from ffs_alloc.c while holding
a bitmap locked. Thus, inodedep_lookup must not go off to do
request_cleanups when being called from these functions. This change
adds a flag, NODELAY, that can be passed to inodedep_lookup to let
it know that it should not do background processing in those cases.

2) The return value from request_cleanup when helping out with the
cleanup was 0 instead of 1. This meant that despite the fact that
we may have slept while doing the cleanups, the code did not recheck
for the appearance of an inodedep (e.g., goto top in inodedep_lookup).
This lead to the softdep inconsistency in which we ended up with
two inodedep's for the same inode.

Reviewed by:	Peter Wemm <peter@yahoo-inc.com>,
		Matt Dillon <dillon@earth.backplane.com>
2001-02-20 11:14:38 +00:00
Jeroen Ruigrok van der Werven
d7d97eb0aa Preceed/preceeding are not english words. Use precede and preceding. 2001-02-18 10:43:53 +00:00
Jake Burkholder
d5a08a6065 Implement a unified run queue and adjust priority levels accordingly.
- All processes go into the same array of queues, with different
  scheduling classes using different portions of the array.  This
  allows user processes to have their priorities propogated up into
  interrupt thread range if need be.
- I chose 64 run queues as an arbitrary number that is greater than
  32.  We used to have 4 separate arrays of 32 queues each, so this
  may not be optimal.  The new run queue code was written with this
  in mind; changing the number of run queues only requires changing
  constants in runq.h and adjusting the priority levels.
- The new run queue code takes the run queue as a parameter.  This
  is intended to be used to create per-cpu run queues.  Implement
  wrappers for compatibility with the old interface which pass in
  the global run queue structure.
- Group the priority level, user priority, native priority (before
  propogation) and the scheduling class into a struct priority.
- Change any hard coded priority levels that I found to use
  symbolic constants (TTIPRI and TTOPRI).
- Remove the curpriority global variable and use that of curproc.
  This was used to detect when a process' priority had lowered and
  it should yield.  We now effectively yield on every interrupt.
- Activate propogate_priority().  It should now have the desired
  effect without needing to also propogate the scheduling class.
- Temporarily comment out the call to vm_page_zero_idle() in the
  idle loop.  It interfered with propogate_priority() because
  the idle process needed to do a non-blocking acquire of Giant
  and then other processes would try to propogate their priority
  onto it.  The idle process should not do anything except idle.
  vm_page_zero_idle() will return in the form of an idle priority
  kernel thread which is woken up at apprioriate times by the vm
  system.
- Update struct kinfo_proc to the new priority interface.  Deliberately
  change its size by adjusting the spare fields.  It remained the same
  size, but the layout has changed, so userland processes that use it
  would parse the data incorrectly.  The size constraint should really
  be changed to an arbitrary version number.  Also add a debug.sizeof
  sysctl node for struct kinfo_proc.
2001-02-12 00:20:08 +00:00
Bosko Milekic
9ed346bab0 Change and clean the mutex lock interface.
mtx_enter(lock, type) becomes:

mtx_lock(lock) for sleep locks (MTX_DEF-initialized locks)
mtx_lock_spin(lock) for spin locks (MTX_SPIN-initialized)

similarily, for releasing a lock, we now have:

mtx_unlock(lock) for MTX_DEF and mtx_unlock_spin(lock) for MTX_SPIN.
We change the caller interface for the two different types of locks
because the semantics are entirely different for each case, and this
makes it explicitly clear and, at the same time, it rids us of the
extra `type' argument.

The enter->lock and exit->unlock change has been made with the idea
that we're "locking data" and not "entering locked code" in mind.

Further, remove all additional "flags" previously passed to the
lock acquire/release routines with the exception of two:

MTX_QUIET and MTX_NOSWITCH

The functionality of these flags is preserved and they can be passed
to the lock/unlock routines by calling the corresponding wrappers:

mtx_{lock, unlock}_flags(lock, flag(s)) and
mtx_{lock, unlock}_spin_flags(lock, flag(s)) for MTX_DEF and MTX_SPIN
locks, respectively.

Re-inline some lock acq/rel code; in the sleep lock case, we only
inline the _obtain_lock()s in order to ensure that the inlined code
fits into a cache line. In the spin lock case, we inline recursion and
actually only perform a function call if we need to spin. This change
has been made with the idea that we generally tend to avoid spin locks
and that also the spin locks that we do have and are heavily used
(i.e. sched_lock) do recurse, and therefore in an effort to reduce
function call overhead for some architectures (such as alpha), we
inline recursion for this case.

Create a new malloc type for the witness code and retire from using
the M_DEV type. The new type is called M_WITNESS and is only declared
if WITNESS is enabled.

Begin cleaning up some machdep/mutex.h code - specifically updated the
"optimized" inlined code in alpha/mutex.h and wrote MTX_LOCK_SPIN
and MTX_UNLOCK_SPIN asm macros for the i386/mutex.h as we presently
need those.

Finally, caught up to the interface changes in all sys code.

Contributors: jake, jhb, jasone (in no particular order)
2001-02-09 06:11:45 +00:00
Poul-Henning Kamp
37d4006626 Another round of the <sys/queue.h> FOREACH transmogriffer.
Created with:   sed(1)
Reviewed by:    md5(1)
2001-02-04 16:08:18 +00:00
Poul-Henning Kamp
fc2ffbe604 Mechanical change to use <sys/queue.h> macro API instead of
fondling implementation details.

Created with: sed(1)
Reviewed by: md5(1)
2001-02-04 13:13:25 +00:00
Poul-Henning Kamp
ef9e85abba Use <sys/queue.h> macro API. 2001-02-04 12:37:48 +00:00
Matthew Dillon
f8e071a1eb Fix a race between the syncer and umount. When you umount a softupdates
filesystem softdep_process_worklist() is called in a loop until it indicates
that no dependancies remain, but the determination of that fact depends on
there only being one softdep_process_worklist() instance running.  It was
possible for the syncer to also be running softdep_process_worklist()
and the pre-existing checks in the code to prevent this were not sufficient
to prevent the race.  This patch solves the problem.

Approved-by: mckusick
2001-01-30 06:31:59 +00:00
Jason Evans
1b367556b5 Convert all simplelocks to mutexes and remove the simplelock implementations. 2001-01-24 12:35:55 +00:00
Ian Dowse
f55ff3f3ef 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
Kirk McKusick
cb3ab5aaf7 Properly compute the size of the final block of superblock summary information.
Submitted by:	Ian Dowse <iedowse@maths.tcd.ie>
2001-01-12 21:56:55 +00:00
Kirk McKusick
48d617487d 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
Kirk McKusick
6da443cb22 Get rid of spurious check in ffs_truncate for i_size == length
which fails to set the modification time on the file. The same
check a few lines later takes the correct action.

Submitted by:	Ian Dowse <iedowse@maths.tcd.ie>
2000-12-19 04:20:13 +00:00
Assar Westerlund
ca85ca6099 add a stub for softdep_slowdown so that it's possible to build the
kernel without SOFTUPDATES
2000-12-17 23:59:56 +00:00
Seigo Tanimura
937c4dfa08 Do not race for the lock of an inode hash.
Reviewed by:	jhb
2000-12-13 10:04:01 +00:00
Kirk McKusick
1d733bbd10 Preventing runaway kernel soft updates memory, take three.
Previously, the syncer process was the only process in the
system that could process the soft updates background work
list. If enough other processes were adding requests to that
list, it would eventually grow without bound. Because some of
the work list requests require vnodes to be locked, it was
not generally safe to let random processes process the work
list while they already held vnodes locked. By adding a flag
to the work list queue processing function to indicate whether
the calling process could safely lock vnodes, it becomes possible
to co-opt other processes into helping out with the work list.
Now when the worklist gets too large, other processes can safely
help out by picking off those work requests that can be handled
without locking a vnode, leaving only the small number of
requests requiring a vnode lock for the syncer process. With
this change, it appears possible to keep even the nastiest
workloads under control.

Submitted by:	Paul Saab <ps@yahoo-inc.com>
2000-12-13 08:30:35 +00:00
David Malone
7cc0979fd6 Convert more malloc+bzero to malloc+M_ZERO.
Submitted by:	josh@zipperup.org
Submitted by:	Robert Drehmel <robd@gmx.net>
2000-12-08 21:51:06 +00:00
Poul-Henning Kamp
959b7375ed Staticize some malloc M_ instances. 2000-12-08 20:09:00 +00:00
Kirk McKusick
71868b020d More aggressively rate limit the growth of soft dependency structures
in the face of multiple processes doing massive numbers of filesystem
operations. While this patch will work in nearly all situations, there
are still some perverse workloads that can overwhelm the system.
Detecting and handling these perverse workloads will be the subject
of another patch.

Reviewed by:	Paul Saab <ps@yahoo-inc.com>
Obtained from:	Ethan Solomita <ethan@geocast.com>
2000-11-20 06:22:39 +00:00
Matthew Dillon
936524aa02 Implement a low-memory deadlock solution.
Removed most of the hacks that were trying to deal with low-memory
    situations prior to now.

    The new code is based on the concept that I/O must be able to function in
    a low memory situation.  All major modules related to I/O (except
    networking) have been adjusted to allow allocation out of the system
    reserve memory pool.  These modules now detect a low memory situation but
    rather then block they instead continue to operate, then return resources
    to the memory pool instead of cache them or leave them wired.

    Code has been added to stall in a low-memory situation prior to a vnode
    being locked.

    Thus situations where a process blocks in a low-memory condition while
    holding a locked vnode have been reduced to near nothing.  Not only will
    I/O continue to operate, but many prior deadlock conditions simply no
    longer exist.

Implement a number of VFS/BIO fixes

	(found by Ian): in biodone(), bogus-page replacement code, the loop
        was not properly incrementing loop variables prior to a continue
        statement.  We do not believe this code can be hit anyway but we
        aren't taking any chances.  We'll turn the whole section into a
        panic (as it already is in brelse()) after the release is rolled.

	In biodone(), the foff calculation was incorrectly
        clamped to the iosize, causing the wrong foff to be calculated
        for pages in the case of an I/O error or biodone() called without
        initiating I/O.  The problem always caused a panic before.  Now it
        doesn't.  The problem is mainly an issue with NFS.

	Fixed casts for ~PAGE_MASK.  This code worked properly before only
        because the calculations use signed arithmatic.  Better to properly
        extend PAGE_MASK first before inverting it for the 64 bit masking
        op.

	In brelse(), the bogus_page fixup code was improperly throwing
        away the original contents of 'm' when it did the j-loop to
        fix the bogus pages.  The result was that it would potentially
        invalidate parts of the *WRONG* page(!), leading to corruption.

	There may still be cases where a background bitmap write is
        being duplicated, causing potential corruption.  We have identified
        a potentially serious bug related to this but the fix is still TBD.
        So instead this patch contains a KASSERT to detect the problem
  	and panic the machine rather then continue to corrupt the filesystem.
	The problem does not occur very often..  it is very hard to
	reproduce, and it may or may not be the cause of the corruption
	people have reported.

Review by: (VFS/BIO: mckusick, Ian Dowse <iedowse@maths.tcd.ie>)
Testing by: (VM/Deadlock) Paul Saab <ps@yahoo-inc.com>
2000-11-18 23:06:26 +00:00
Kirk McKusick
bd4bd019fb When deleting a file, the ordering of events imposed by soft updates
is to first write the deleted directory entry to disk, second write
the zero'ed inode to disk, and finally to release the freed blocks
and the inode back to the cylinder-group map. As this ordering
requires two disk writes to occur which are normally spaced about
30 seconds apart (except when memory is under duress), it takes
about a minute from the time that a file is deleted until its inode
and data blocks show up in the cylinder-group map for reallocation.
If a file has had only a brief lifetime (less than 30 seconds from
creation to deletion), neither its inode nor its directory entry
may have been written to disk. If its directory entry has not been
written to disk, then we need not wait for that directory block to
be written as the on-disk directory block does not reference the
inode. Similarly, if the allocated inode has never been written to
disk, we do not have to wait for it to be written back either as
its on-disk representation is still zero'ed out. Thus, in the case
of a short lived file, we can simply release the blocks and inode
to the cylinder-group map immediately. As the inode and its blocks
are released immediately, they are immediately available for other
uses. If they are not released for a minute, then other inodes and
blocks must be allocated for short lived files, cluttering up the
vnode and buffer caches. The previous code was a bit too aggressive
in trying to release the blocks and inode back to the cylinder-group
map resulting in their being made available when in fact the inode
on disk had not yet been zero'ed. This patch takes a more conservative
approach to doing the release which avoids doing the release prematurely.
2000-11-14 09:00:25 +00:00
Adrian Chadd
0b0c10b48d Initial commit of IFS - a inode-namespaced FFS. Here is a short
description:

How it works:
--

Basically ifs is a copy of ffs, overriding some vfs/vnops. (Yes, hack.)
I didn't see the need in duplicating all of sys/ufs/ffs to get this
off the ground.

File creation is done through a special file - 'newfile' . When newfile
is called, the system allocates and returns an inode. Note that newfile
is done in a cloning fashion:

fd = open("newfile", O_CREAT|O_RDWR, 0644);
fstat(fd, &st);

printf("new file is %d\n", (int)st.st_ino);

Once you have created a file, you can open() and unlink() it by its returned
inode number retrieved from the stat call, ie:

fd = open("5", O_RDWR);

The creation permissions depend entirely if you have write access to the
root directory of the filesystem.

To get the list of currently allocated inodes, VOP_READDIR has been added
which returns a directory listing of those currently allocated.

--

What this entails:

* patching conf/files and conf/options to include IFS as a new compile
  option (and since ifs depends upon FFS, include the FFS routines)

* An entry in i386/conf/NOTES indicating IFS exists and where to go for
  an explanation

* Unstaticize a couple of routines in src/sys/ufs/ffs/ which the IFS
  routines require (ffs_mount() and ffs_reload())

* a new bunch of routines in src/sys/ufs/ifs/ which implement the IFS
  routines. IFS replaces some of the vfsops, and a handful of vnops -
  most notably are VFS_VGET(), VOP_LOOKUP(), VOP_UNLINK() and VOP_READDIR().
  Any other directory operation is marked as invalid.

What this results in:

* an IFS partition's create permissions are controlled by the perm/ownership of
  the root mount point, just like a normal directory

* Each inode has perm and ownership too

* IFS does *NOT* mean an FFS partition can be opened per inode. This is a
  completely seperate filesystem here

* Softupdates doesn't work with IFS, and really I don't think it needs it.
  Besides, fsck's are FAST. (Try it :-)

* Inodes 0 and 1 aren't allocatable because they are special (dump/swap IIRC).
  Inode 2 isn't allocatable since UFS/FFS locks all inodes in the system against
  this particular inode, and unravelling THAT code isn't trivial. Therefore,
  useful inodes start at 3.

Enjoy, and feedback is definitely appreciated!
2000-10-14 03:02:30 +00:00
Eivind Eklund
7eb9fca557 Blow away the v_specmountpoint define, replacing it with what it was
defined as (rdev->si_mountpoint)
2000-10-09 17:31:39 +00:00
Robert Watson
ff435dcb91 o Move initialization of ump from mp to the top of the function so that
it is defined whenm used in ufs_extattr_uepm_destroy(), fixing a panic
  due to a NULL pointer dereference.

Submitted by:	Wesley Morgan <morganw@chemicals.tacorp.com>
2000-10-06 15:31:28 +00:00
Robert Watson
9de54ba513 o Add call to ufs_extattr_uepm_destroy() in ffs_unmount() so as to clean
up lock on extattrs.
o Get for free a comment indicating where auto-starting of extended
  attributes will eventually occur, as it was in my commit tree also.
  No implementation change here, only a comment.
2000-10-04 04:44:51 +00:00
Jason Evans
a18b1f1d4d Convert lockmgr locks from using simple locks to using mutexes.
Add lockdestroy() and appropriate invocations, which corresponds to
lockinit() and must be called to clean up after a lockmgr lock is no
longer needed.
2000-10-04 01:29:17 +00:00
Boris Popov
67e871664b Add a lock structure to vnode structure. Previously it was either allocated
separately (nfs, cd9660 etc) or keept as a first element of structure
referenced by v_data pointer(ffs). Such organization leads to known problems
with stacked filesystems.

From this point vop_no*lock*() functions maintain only interlock lock.
vop_std*lock*() functions maintain built-in v_lock structure using lockmgr().
vop_sharedlock() is compatible with vop_stdunlock(), but maintains a shared
lock on vnode.

If filesystem wishes to export lockmgr compatible lock, it can put an address
of this lock to v_vnlock field. This indicates that the upper filesystem
can take advantage of it and use single lock structure for entire (or part)
of stack of vnodes. This field shouldn't be examined or modified by VFS code
except for initialization purposes.

Reviewed in general by:	mckusick
2000-09-25 15:24:04 +00:00
Robert Watson
907da7c385 o Permit UFS Extended Attributes to be associated with special devices
and FIFOs.

Obtained from:	TrustedBSD Project
2000-09-21 19:06:02 +00:00
Dag-Erling Smørgrav
8461bdba85 Silence a warning. 2000-09-17 19:41:26 +00:00
Kirk McKusick
52a3bfa2e7 Cannot do MALLOC with M_WAITOK while holding ACQUIRE_LOCK
Obtained from:	Ethan Solomita <ethan@geocast.com>
2000-09-07 23:02:55 +00:00
Jason Evans
0384fff8c5 Major update to the way synchronization is done in the kernel. Highlights
include:

* Mutual exclusion is used instead of spl*().  See mutex(9).  (Note: The
  alpha port is still in transition and currently uses both.)

* Per-CPU idle processes.

* Interrupts are run in their own separate kernel threads and can be
  preempted (i386 only).

Partially contributed by:	BSDi (BSD/OS)
Submissions by (at least):	cp, dfr, dillon, grog, jake, jhb, sheldonh
2000-09-07 01:33:02 +00:00
Tor Egge
b5ee7ec63a Initialize *countp to 0 in stub for softdep_flushworklist().
This allows ffs_fsync() to break out of a loop that might otherwise
be infinite on kernels compiled without the SOFTUPDATES option.
The observed symptom was a system hang at the first unmount attempt.
2000-08-09 00:41:54 +00:00
Ollivier Robert
8694d8e912 Fix the lockmgr panic everyone is seeing at shutdown time.
vput assumes curproc is the lock holder, but it's not true in this case.

Thanks a lot Luoqi !

Submitted by:	luoqi
Tested by:	phk
2000-08-01 14:15:07 +00:00
Peter Wemm
6ee6b42ef7 Minor change: fix warning - move a 'struct vnode *vp' declaration inside a
#ifdef DIAGNOSTIC to match its corresponding usage.
2000-07-28 22:27:00 +00:00
Kirk McKusick
3592b7155c 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
Kirk McKusick
55ba28c60a Add stub for softdep_flushworklist() so that kernels compiled
without the SOFTUPDATES option will load correctly.

Obtained from:	John Baldwin <jhb@bsdi.com>
2000-07-25 05:28:59 +00:00
Kirk McKusick
9b97113391 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
Boris Popov
3fbd97427e Prevent possible dereference of NULL pointer.
Submitted by:	Marius Bendiksen <mbendiks@eunet.no>
2000-07-13 02:17:14 +00:00
Kirk McKusick
d303f71fdc 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
Kirk McKusick
f2a2857bb3 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
Kirk McKusick
d4c1816924 Clean up warning about undeclared function by declaring softdep_fsync
in mount.h instead of ffs_extern.h. The correct solution is to use
an indirect function pointer so that the kernel does not have to be
built with options FFS, but that will be left for another day.
2000-07-11 19:28:26 +00:00
Kirk McKusick
cc3962a9cd Delete README as it is now obsolete. Relevant information is in
README.softupdates.
2000-07-08 02:32:49 +00:00
Kirk McKusick
876578906d Update to reflect current status. 2000-07-08 02:31:21 +00:00
Kirk McKusick
22e5a6234e Get userland visible flags added for snapshots to give a few days
advance preparation for them to get migrated into place so that
subsequent changes in utilities will not fail to compile for lack
of up-to-date header files in /usr/include.
2000-07-04 04:58:34 +00:00
Poul-Henning Kamp
3275cf7379 Make the two calls from kern/* into softupdates #ifdef SOFTUPDATES,
that is way cleaner than using the softupdates_stub stunt, which
should be killed when convenient.

Discussed with:	mckusick
2000-07-03 13:26:54 +00:00
Andrey A. Chernov
2d90744fd8 Remove obsoleted info about linking from contrib 2000-06-24 13:29:25 +00:00
Kirk McKusick
858c16fab8 Update to new copyright. 2000-06-22 00:29:53 +00:00
Kirk McKusick
6019e6208f When running with quotas enabled on a filesystem using soft updates,
the system would panic when a user's inode quota was exceeded (see
PR 18959 for details). This fixes that problem.

PR:		18959
Submitted by:	Jason Godsey <jason@unixguy.fidalgo.net>
2000-06-18 22:14:28 +00:00