freebsd-nq/sys/ufs/ffs/ffs_vnops.c
Kirk McKusick cf60e8e4bf Several performance improvements for soft updates have been added:
1) Fastpath deletions. When a file is being deleted, check to see if it
   was so recently created that its inode has not yet been written to
   disk. If so, the delete can proceed to immediately free the inode.
2) Background writes: No file or block allocations can be done while the
   bitmap is being written to disk. To avoid these stalls, the bitmap is
   copied to another buffer which is written thus leaving the original
   available for futher allocations.
3) Link count tracking. Constantly track the difference in i_effnlink and
   i_nlink so that inodes that have had no change other than i_effnlink
   need not be written.
4) Identify buffers with rollback dependencies so that the buffer flushing
   daemon can choose to skip over them.
2000-01-10 00:24:24 +00:00

276 lines
8.0 KiB
C

/*
* Copyright (c) 1982, 1986, 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 THE REGENTS OR CONTRIBUTORS 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.
*
* @(#)ffs_vnops.c 8.15 (Berkeley) 5/14/95
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/resourcevar.h>
#include <sys/signalvar.h>
#include <sys/kernel.h>
#include <sys/stat.h>
#include <sys/buf.h>
#include <sys/proc.h>
#include <sys/mount.h>
#include <sys/vnode.h>
#include <sys/conf.h>
#include <machine/limits.h>
#include <vm/vm.h>
#include <vm/vm_page.h>
#include <vm/vm_object.h>
#include <vm/vm_extern.h>
#include <ufs/ufs/quota.h>
#include <ufs/ufs/inode.h>
#include <ufs/ufs/ufsmount.h>
#include <ufs/ufs/ufs_extern.h>
#include <ufs/ffs/fs.h>
#include <ufs/ffs/ffs_extern.h>
static int ffs_fsync __P((struct vop_fsync_args *));
static int ffs_getpages __P((struct vop_getpages_args *));
static int ffs_putpages __P((struct vop_putpages_args *));
static int ffs_read __P((struct vop_read_args *));
static int ffs_write __P((struct vop_write_args *));
/* Global vfs data structures for ufs. */
vop_t **ffs_vnodeop_p;
static struct vnodeopv_entry_desc ffs_vnodeop_entries[] = {
{ &vop_default_desc, (vop_t *) ufs_vnoperate },
{ &vop_fsync_desc, (vop_t *) ffs_fsync },
{ &vop_getpages_desc, (vop_t *) ffs_getpages },
{ &vop_putpages_desc, (vop_t *) ffs_putpages },
{ &vop_read_desc, (vop_t *) ffs_read },
{ &vop_balloc_desc, (vop_t *) ffs_balloc },
{ &vop_reallocblks_desc, (vop_t *) ffs_reallocblks },
{ &vop_write_desc, (vop_t *) ffs_write },
{ NULL, NULL }
};
static struct vnodeopv_desc ffs_vnodeop_opv_desc =
{ &ffs_vnodeop_p, ffs_vnodeop_entries };
vop_t **ffs_specop_p;
static struct vnodeopv_entry_desc ffs_specop_entries[] = {
{ &vop_default_desc, (vop_t *) ufs_vnoperatespec },
{ &vop_fsync_desc, (vop_t *) ffs_fsync },
{ NULL, NULL }
};
static struct vnodeopv_desc ffs_specop_opv_desc =
{ &ffs_specop_p, ffs_specop_entries };
vop_t **ffs_fifoop_p;
static struct vnodeopv_entry_desc ffs_fifoop_entries[] = {
{ &vop_default_desc, (vop_t *) ufs_vnoperatefifo },
{ &vop_fsync_desc, (vop_t *) ffs_fsync },
{ NULL, NULL }
};
static struct vnodeopv_desc ffs_fifoop_opv_desc =
{ &ffs_fifoop_p, ffs_fifoop_entries };
VNODEOP_SET(ffs_vnodeop_opv_desc);
VNODEOP_SET(ffs_specop_opv_desc);
VNODEOP_SET(ffs_fifoop_opv_desc);
#include <ufs/ufs/ufs_readwrite.c>
/*
* Synch an open file.
*/
/* ARGSUSED */
static int
ffs_fsync(ap)
struct vop_fsync_args /* {
struct vnode *a_vp;
struct ucred *a_cred;
int a_waitfor;
struct proc *a_p;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
struct buf *bp;
struct buf *nbp;
int s, error, wait, passes, skipmeta;
daddr_t lbn;
wait = (ap->a_waitfor == MNT_WAIT);
if (vn_isdisk(vp)) {
lbn = INT_MAX;
if (vp->v_specmountpoint != NULL &&
(vp->v_specmountpoint->mnt_flag & MNT_SOFTDEP))
softdep_fsync_mountdev(vp);
} else {
struct inode *ip;
ip = VTOI(vp);
lbn = lblkno(ip->i_fs, (ip->i_size + ip->i_fs->fs_bsize - 1));
}
/*
* Flush all dirty buffers associated with a vnode.
*/
passes = NIADDR + 1;
skipmeta = 0;
if (wait)
skipmeta = 1;
s = splbio();
loop:
for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp;
bp = TAILQ_NEXT(bp, b_vnbufs))
bp->b_flags &= ~B_SCANNED;
for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) {
nbp = TAILQ_NEXT(bp, b_vnbufs);
/*
* Reasons to skip this buffer: it has already been considered
* on this pass, this pass is the first time through on a
* synchronous flush request and the buffer being considered
* is metadata, the buffer has dependencies that will cause
* it to be redirtied and it has not already been deferred,
* or it is already being written.
*/
if ((bp->b_flags & B_SCANNED) != 0)
continue;
bp->b_flags |= B_SCANNED;
if ((skipmeta == 1 && bp->b_lblkno < 0))
continue;
if (!wait && LIST_FIRST(&bp->b_dep) != NULL &&
(bp->b_flags & B_DEFERRED) == 0 &&
bioops.io_countdeps && (*bioops.io_countdeps)(bp, 0)) {
bp->b_flags |= B_DEFERRED;
continue;
}
if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT))
continue;
if ((bp->b_flags & B_DELWRI) == 0)
panic("ffs_fsync: not dirty");
if (vp != bp->b_vp)
panic("ffs_fsync: vp != vp->b_vp");
/*
* If this is a synchronous flush request, or it is not a
* file or device, start the write on this buffer immediatly.
*/
if (wait || (vp->v_type != VREG && vp->v_type != VBLK)) {
/*
* On our final pass through, do all I/O synchronously
* so that we can find out if our flush is failing
* because of write errors.
*/
if (passes > 0 || !wait) {
if ((bp->b_flags & B_CLUSTEROK) && !wait) {
BUF_UNLOCK(bp);
(void) vfs_bio_awrite(bp);
} else {
bremfree(bp);
splx(s);
(void) bawrite(bp);
s = splbio();
}
} else {
bremfree(bp);
splx(s);
if ((error = bwrite(bp)) != 0)
return (error);
s = splbio();
}
} else if ((vp->v_type == VREG) && (bp->b_lblkno >= lbn)) {
/*
* If the buffer is for data that has been truncated
* off the file, then throw it away.
*/
bremfree(bp);
bp->b_flags |= B_INVAL | B_NOCACHE;
splx(s);
brelse(bp);
s = splbio();
} else {
BUF_UNLOCK(bp);
vfs_bio_awrite(bp);
}
/*
* Since we may have slept during the I/O, we need
* to start from a known point.
*/
nbp = TAILQ_FIRST(&vp->v_dirtyblkhd);
}
/*
* If we were asked to do this synchronously, then go back for
* another pass, this time doing the metadata.
*/
if (skipmeta) {
skipmeta = 0;
goto loop;
}
if (wait) {
while (vp->v_numoutput) {
vp->v_flag |= VBWAIT;
(void) tsleep((caddr_t)&vp->v_numoutput,
PRIBIO + 4, "ffsfsn", 0);
}
/*
* Ensure that any filesystem metatdata associated
* with the vnode has been written.
*/
splx(s);
if ((error = softdep_sync_metadata(ap)) != 0)
return (error);
s = splbio();
if (!TAILQ_EMPTY(&vp->v_dirtyblkhd)) {
/*
* Block devices associated with filesystems may
* have new I/O requests posted for them even if
* the vnode is locked, so no amount of trying will
* get them clean. Thus we give block devices a
* good effort, then just give up. For all other file
* types, go around and try again until it is clean.
*/
if (passes > 0) {
passes -= 1;
goto loop;
}
#ifdef DIAGNOSTIC
if (!vn_isdisk(vp))
vprint("ffs_fsync: dirty", vp);
#endif
}
}
splx(s);
return (UFS_UPDATE(vp, wait));
}