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/* $OpenBSD: lfs_bio.c,v 1.11 2004/06/21 23:50:38 tholo Exp $ */
/* $NetBSD: lfs_bio.c,v 1.5 1996/02/09 22:28:49 christos Exp $ */
/*
* Copyright (c) 1991, 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. 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.
*
* @(#)lfs_bio.c 8.10 (Berkeley) 6/10/95
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/buf.h>
#include <sys/vnode.h>
#include <sys/resourcevar.h>
#include <sys/mount.h>
#include <sys/kernel.h>
#include <sys/timeout.h>
#include <ufs/ufs/quota.h>
#include <ufs/ufs/inode.h>
#include <ufs/ufs/ufsmount.h>
#include <ufs/ufs/ufs_extern.h>
#include <ufs/lfs/lfs.h>
#include <ufs/lfs/lfs_extern.h>
/*
* LFS block write function.
*
* XXX
* No write cost accounting is done.
* This is almost certainly wrong for synchronous operations and NFS.
*/
int lfs_allclean_wakeup; /* Cleaner wakeup address. */
int locked_queue_count; /* XXX Count of locked-down buffers. */
int lfs_writing; /* Set if already kicked off a writer
because of buffer space */
/*
#define WRITE_THRESHHOLD ((nbuf >> 2) - 10)
#define WAIT_THRESHHOLD ((nbuf >> 1) - 10)
*/
#define WAIT_THRESHHOLD (nbuf - (nbuf >> 2) - 10)
#define WRITE_THRESHHOLD ((nbuf >> 1) - 10)
#define LFS_BUFWAIT 2
struct timeout wakeup_timeout;
int
lfs_bwrite(v)
void *v;
{
struct vop_bwrite_args /* {
struct buf *a_bp;
} */ *ap = v;
register struct buf *bp = ap->a_bp;
struct lfs *fs;
struct inode *ip;
int db, error, s;
/*
* Set the delayed write flag and use reassignbuf to move the buffer
* from the clean list to the dirty one.
*
* Set the B_LOCKED flag and unlock the buffer, causing brelse to move
* the buffer onto the LOCKED free list. This is necessary, otherwise
* getnewbuf() would try to reclaim the buffers using bawrite, which
* isn't going to work.
*
* XXX we don't let meta-data writes run out of space because they can
* come from the segment writer. We need to make sure that there is
* enough space reserved so that there's room to write meta-data
* blocks.
*/
if (!(bp->b_flags & B_LOCKED)) {
fs = VFSTOUFS(bp->b_vp->v_mount)->um_lfs;
db = fragstodb(fs, numfrags(fs, bp->b_bcount));
while (!LFS_FITS(fs, db) && !IS_IFILE(bp) &&
bp->b_lblkno > 0) {
/* Out of space, need cleaner to run */
wakeup(&lfs_allclean_wakeup);
wakeup(&fs->lfs_nextseg);
error = tsleep(&fs->lfs_avail, PCATCH | PUSER,
"cleaner", NULL);
if (error) {
brelse(bp);
return (error);
}
}
ip = VTOI((bp)->b_vp);
if (!(ip->i_flag & IN_MODIFIED))
++fs->lfs_uinodes;
ip->i_flag |= IN_CHANGE | IN_MODIFIED | IN_UPDATE;
fs->lfs_avail -= db;
++locked_queue_count;
bp->b_flags |= B_LOCKED;
TAILQ_INSERT_TAIL(&bdirties, bp, b_synclist);
bp->b_synctime = time_second + 30;
s = splbio();
if (bdirties.tqh_first == bp) {
if (timeout_triggered(&wakeup_timeout))
timeout_del(&wakeup_timeout);
if (!timeout_initialized(&wakeup_timeout))
timeout_set(&wakeup_timeout, wakeup, &bdirties);
timeout_add(&wakeup_timeout, 30 * hz);
}
bp->b_flags &= ~(B_READ | B_ERROR);
buf_dirty(bp);
splx(s);
}
brelse(bp);
return (0);
}
/*
* XXX
* This routine flushes buffers out of the B_LOCKED queue when LFS has too
* many locked down. Eventually the pageout daemon will simply call LFS
* when pages need to be reclaimed. Note, we have one static count of locked
* buffers, so we can't have more than a single file system. To make this
* work for multiple file systems, put the count into the mount structure.
*/
void
lfs_flush()
{
register struct mount *mp;
#ifdef DOSTATS
++lfs_stats.write_exceeded;
#endif
if (lfs_writing)
return;
lfs_writing = 1;
for (mp = mountlist.cqh_first; mp != (void *)&mountlist;
mp = mp->mnt_list.cqe_next) {
/* The lock check below is to avoid races with unmount. */
if (!strncmp(&mp->mnt_stat.f_fstypename[0], MOUNT_LFS, MFSNAMELEN) &&
(mp->mnt_flag & (MNT_RDONLY)) == 0 &&
!((((struct ufsmount *)mp->mnt_data))->ufsmount_u.lfs)->lfs_dirops ) {
/*
* We set the queue to 0 here because we are about to
* write all the dirty buffers we have. If more come
* in while we're writing the segment, they may not
* get written, so we want the count to reflect these
* new writes after the segwrite completes.
*/
#ifdef DOSTATS
++lfs_stats.flush_invoked;
#endif
lfs_segwrite(mp, 0);
}
}
lfs_writing = 0;
}
int
lfs_check(vp, blkno)
struct vnode *vp;
ufs_daddr_t blkno;
{
int error;
error = 0;
if (incore(vp, blkno))
return (0);
if (locked_queue_count > WRITE_THRESHHOLD)
lfs_flush();
/* If out of buffers, wait on writer */
while (locked_queue_count > WAIT_THRESHHOLD) {
#ifdef DOSTATS
++lfs_stats.wait_exceeded;
#endif
error = tsleep(&locked_queue_count, PCATCH | PUSER, "buffers",
hz * LFS_BUFWAIT);
}
return (error);
}
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