freebsd-dev/sys/ufs/ffs/ffs_vnops.c
Kirk McKusick eef33ce9bd When fsync'ing a file on a filesystem using soft updates, we first try
to write all the dirty blocks. If some of those blocks have dependencies,
they will be remarked dirty when the I/O completes. On systems with
really fast I/O systems, it is possible to get in an infinite loop trying
to flush the buffers, because the I/O finishes before we can get all the
dirty buffers off the v_dirtyblkhd list and into the I/O queue. (The
previous algorithm looped over the v_dirtyblkhd list writing out buffers
until the list emptied.) So, now we mark each buffer that we try to
write so that we can distinguish the ones that are being remarked dirty
from those that we have not yet tried to flush. Once we have tried to
push every buffer once, we then push any associated metadata that is
causing the remaining buffers to be redirtied.

Submitted by:	Matthew Dillon <dillon@apollo.backplane.com>
1999-03-02 04:04:31 +00:00

260 lines
7.5 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
* $Id: ffs_vnops.c,v 1.54 1999/01/07 16:14:17 bde Exp $
*/
#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 <machine/limits.h>
#include <vm/vm.h>
#include <vm/vm_prot.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, passes, skipmeta;
daddr_t lbn;
if (vp->v_type == VBLK) {
lbn = INT_MAX;
} 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;
skipmeta = 0;
if (ap->a_waitfor == MNT_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);
/*
* First time through on a synchronous call,
* or if it's already scheduled, skip to the next
* buffer
*/
if ((bp->b_flags & (B_BUSY | B_SCANNED)) ||
((skipmeta == 1) && (bp->b_lblkno < 0)))
continue;
if ((bp->b_flags & B_DELWRI) == 0)
panic("ffs_fsync: not dirty");
/*
* If data is outstanding to another vnode, or we were
* asked to wait for everything, or it's not a file or BDEV,
* start the IO on this buffer immediatly.
*/
bp->b_flags |= B_SCANNED;
if (((bp->b_vp != vp) || (ap->a_waitfor == MNT_WAIT)) ||
((vp->v_type != VREG) && (vp->v_type != VBLK))) {
/*
* Wait for I/O associated with indirect blocks to
* complete, since there is no way to quickly wait
* for them below.
*/
if ((bp->b_vp == vp) || (ap->a_waitfor != MNT_WAIT)) {
if ((bp->b_flags & B_CLUSTEROK) &&
ap->a_waitfor != MNT_WAIT) {
(void) vfs_bio_awrite(bp);
} else {
bremfree(bp);
bp->b_flags |= B_BUSY;
splx(s);
(void) bawrite(bp);
s = splbio();
}
} else {
bremfree(bp);
bp->b_flags |= B_BUSY;
splx(s);
(void) bwrite(bp);
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_BUSY | B_INVAL | B_NOCACHE;
splx(s);
brelse(bp);
s = splbio();
} else {
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 (ap->a_waitfor == MNT_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 (vp->v_type != VBLK)
vprint("ffs_fsync: dirty", vp);
#endif
}
}
splx(s);
return (UFS_UPDATE(vp, ap->a_waitfor == MNT_WAIT));
}