/*
* Buffer cleaning daemon.
*/
void
buf_daemon(struct proc *p)
{
int s;
struct buf *bp;
struct timeval starttime, timediff;
cleanerproc = curproc;
for (;;) {
if (numdirtypages < hidirtypages) {
tsleep(&bd_req, PRIBIO - 7, "cleaner", 0);
}
starttime = time;
s = splbio();
while ((bp = TAILQ_FIRST(&bufqueues[BQ_DIRTY]))) {
bremfree(bp);
SET(bp->b_flags, B_BUSY);
splx(s);
if (ISSET(bp->b_flags, B_INVAL)) {
brelse(bp);
s = splbio();
continue;
}
#ifdef DIAGNOSTIC
if (!ISSET(bp->b_flags, B_DELWRI))
panic("Clean buffer on BQ_DIRTY");
#endif
if (LIST_FIRST(&bp->b_dep) != NULL &&
!ISSET(bp->b_flags, B_DEFERRED) &&
buf_countdeps(bp, 0, 1)) {
SET(bp->b_flags, B_DEFERRED);
s = splbio();
numfreepages += btoc(bp->b_bufsize);
numdirtypages += btoc(bp->b_bufsize);
binstailfree(bp, &bufqueues[BQ_DIRTY]);
CLR(bp->b_flags, B_BUSY);
continue;
}
bawrite(bp);
if (numdirtypages < lodirtypages)
break;
/* Never allow processing to run for more than 1 sec */
timersub(&time, &starttime, &timediff);
if (timediff.tv_sec)
break;
s = splbio();
}
}
}
static int
ffs_checkdeferred(struct buf *bp)
{
if (LIST_FIRST(&bp->b_dep) != NULL &&
(bp->b_flags & B_DEFERRED) == 0 &&
buf_countdeps(bp, 0)) {
bp->b_flags |= B_DEFERRED;
return(1);
}
return(0);
}
/*
* Synch an open file.
*/
int
ffs_fsync(void *v)
{
struct vop_fsync_args *ap = v;
struct vnode *vp = ap->a_vp;
struct buf *bp, *nbp;
int s, error, passes, skipmeta;
if (vp->v_type == VBLK &&
vp->v_specmountpoint != NULL &&
(vp->v_specmountpoint->mnt_flag & MNT_SOFTDEP))
softdep_fsync_mountdev(vp, ap->a_waitfor);
/*
* Flush all dirty buffers associated with a vnode.
*/
passes = NIADDR + 1;
skipmeta = 0;
if (ap->a_waitfor == MNT_WAIT)
skipmeta = 1;
s = splbio();
loop:
for (bp = LIST_FIRST(&vp->v_dirtyblkhd); bp;
bp = LIST_NEXT(bp, b_vnbufs))
bp->b_flags &= ~B_SCANNED;
for (bp = LIST_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) {
nbp = LIST_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_BUSY | B_SCANNED))
continue;
if ((bp->b_flags & B_DELWRI) == 0)
panic("ffs_fsync: not dirty");
if (skipmeta && bp->b_lblkno < 0)
continue;
if (ap->a_waitfor != MNT_WAIT &&
LIST_FIRST(&bp->b_dep) != NULL &&
(bp->b_flags & B_DEFERRED) == 0 &&
buf_countdeps(bp, 0, 1)) {
bp->b_flags |= B_DEFERRED;
continue;
}
bremfree(bp);
buf_acquire(bp);
bp->b_flags |= B_SCANNED;
splx(s);
/*
* 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 || ap->a_waitfor != MNT_WAIT)
(void) bawrite(bp);
else if ((error = bwrite(bp)) != 0)
return (error);
s = splbio();
/*
* Since we may have slept during the I/O, we need
* to start from a known point.
*/
nbp = LIST_FIRST(&vp->v_dirtyblkhd);
}
if (skipmeta) {
skipmeta = 0;
goto loop;
}
if (ap->a_waitfor == MNT_WAIT) {
vwaitforio(vp, 0, "ffs_fsync", 0);
/*
* Ensure that any filesystem metadata associated
* with the vnode has been written.
*/
splx(s);
if ((error = softdep_sync_metadata(ap)) != 0)
return (error);
s = splbio();
if (!LIST_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(VTOI(vp), ap->a_waitfor == MNT_WAIT));
}
/*
* Buffer cleaning daemon.
*/
void
buf_daemon(struct proc *p)
{
struct timeval starttime, timediff;
struct buf *bp = NULL;
int s, pushed = 0;
cleanerproc = curproc;
s = splbio();
for (;;) {
if (bp == NULL || (pushed >= 16 &&
UNCLEAN_PAGES < hidirtypages &&
bcstats.kvaslots_avail > 2 * RESERVE_SLOTS)){
pushed = 0;
/*
* Wake up anyone who was waiting for buffers
* to be released.
*/
if (needbuffer) {
needbuffer = 0;
wakeup(&needbuffer);
}
tsleep(&bd_req, PRIBIO - 7, "cleaner", 0);
}
getmicrouptime(&starttime);
while ((bp = bufcache_getdirtybuf())) {
struct timeval tv;
if (UNCLEAN_PAGES < lodirtypages &&
bcstats.kvaslots_avail > 2 * RESERVE_SLOTS &&
pushed >= 16)
break;
bufcache_take(bp);
buf_acquire(bp);
splx(s);
if (ISSET(bp->b_flags, B_INVAL)) {
brelse(bp);
s = splbio();
continue;
}
#ifdef DIAGNOSTIC
if (!ISSET(bp->b_flags, B_DELWRI))
panic("Clean buffer on dirty queue");
#endif
if (LIST_FIRST(&bp->b_dep) != NULL &&
!ISSET(bp->b_flags, B_DEFERRED) &&
buf_countdeps(bp, 0, 0)) {
SET(bp->b_flags, B_DEFERRED);
s = splbio();
bufcache_release(bp);
buf_release(bp);
continue;
}
bawrite(bp);
pushed++;
/* Never allow processing to run for more than 1 sec */
getmicrouptime(&tv);
timersub(&tv, &starttime, &timediff);
s = splbio();
if (timediff.tv_sec)
break;
}
}
}
