Author: mdf
Date: Wed Sep 15 15:33:51 2010
New Revision: 212664
URL: http://svn.freebsd.org/changeset/base/212664
Log:
Revert r212563, which was a MFC of r209053, as it introduced an unlocked
read/modify/write of b_vflags. The unlocked access is fixed in CURRENT
and stable/8 by r211213 and its MFC, r212583.
Rather than MFC to stable/7, reverting the injecting code seems
preferable.
Modified:
stable/7/sys/kern/vfs_bio.c
stable/7/sys/sys/buf.h
Directory Properties:
stable/7/sys/ (props changed)
stable/7/sys/cddl/contrib/opensolaris/ (props changed)
stable/7/sys/contrib/dev/acpica/ (props changed)
stable/7/sys/contrib/pf/ (props changed)
Modified: stable/7/sys/kern/vfs_bio.c
==============================================================================
--- stable/7/sys/kern/vfs_bio.c Wed Sep 15 15:18:41 2010 (r212663)
+++ stable/7/sys/kern/vfs_bio.c Wed Sep 15 15:33:51 2010 (r212664)
@@ -381,16 +381,10 @@ runningbufwakeup(struct buf *bp)
*/
static __inline void
-bufcountwakeup(struct buf *bp)
+bufcountwakeup(void)
{
- int old;
- KASSERT((bp->b_vflags & BV_INFREECNT) == 0,
- ("buf %p already counted as free", bp));
- bp->b_vflags |= BV_INFREECNT;
- old = atomic_fetchadd_int(&numfreebuffers, 1);
- KASSERT(old >= 0 && old < nbuf,
- ("numfreebuffers climbed to %d", old + 1));
+ atomic_add_int(&numfreebuffers, 1);
mtx_lock(&nblock);
if (needsbuffer) {
needsbuffer &= ~VFS_BIO_NEED_ANY;
@@ -593,7 +587,7 @@ bufinit(void)
bp->b_rcred = NOCRED;
bp->b_wcred = NOCRED;
bp->b_qindex = QUEUE_EMPTY;
- bp->b_vflags = BV_INFREECNT; /* buf is counted as free */
+ bp->b_vflags = 0;
bp->b_xflags = 0;
LIST_INIT(&bp->b_dep);
BUF_LOCKINIT(bp);
@@ -694,7 +688,6 @@ bfreekva(struct buf *bp)
void
bremfree(struct buf *bp)
{
- int old;
CTR3(KTR_BUF, "bremfree(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags);
KASSERT(BUF_REFCNT(bp), ("bremfree: buf must be locked."));
@@ -705,13 +698,8 @@ bremfree(struct buf *bp)
bp->b_flags |= B_REMFREE;
/* Fixup numfreebuffers count. */
- if ((bp->b_flags & B_INVAL) || (bp->b_flags & B_DELWRI) == 0) {
- KASSERT((bp->b_vflags & BV_INFREECNT) != 0,
- ("buf %p not counted in numfreebuffers", bp));
- bp->b_vflags &= ~BV_INFREECNT;
- old = atomic_fetchadd_int(&numfreebuffers, -1);
- KASSERT(old > 0, ("numfreebuffers dropped to %d", old - 1));
- }
+ if ((bp->b_flags & B_INVAL) || (bp->b_flags & B_DELWRI) == 0)
+ atomic_subtract_int(&numfreebuffers, 1);
}
/*
@@ -737,8 +725,6 @@ bremfreef(struct buf *bp)
static void
bremfreel(struct buf *bp)
{
- int old;
-
CTR3(KTR_BUF, "bremfreel(%p) vp %p flags %X",
bp, bp->b_vp, bp->b_flags);
KASSERT(BUF_REFCNT(bp), ("bremfreel: buffer %p not locked.", bp));
@@ -761,13 +747,8 @@ bremfreel(struct buf *bp)
* delayed-write, the buffer was free and we must decrement
* numfreebuffers.
*/
- if ((bp->b_flags & B_INVAL) || (bp->b_flags & B_DELWRI) == 0) {
- KASSERT((bp->b_vflags & BV_INFREECNT) != 0,
- ("buf %p not counted in numfreebuffers", bp));
- bp->b_vflags &= ~BV_INFREECNT;
- old = atomic_fetchadd_int(&numfreebuffers, -1);
- KASSERT(old > 0, ("numfreebuffers dropped to %d", old - 1));
- }
+ if ((bp->b_flags & B_INVAL) || (bp->b_flags & B_DELWRI) == 0)
+ atomic_subtract_int(&numfreebuffers, 1);
}
@@ -1471,7 +1452,7 @@ brelse(struct buf *bp)
*/
if (!(bp->b_flags & B_DELWRI))
- bufcountwakeup(bp);
+ bufcountwakeup();
/*
* Something we can maybe free or reuse
@@ -1561,7 +1542,7 @@ bqrelse(struct buf *bp)
mtx_unlock(&bqlock);
if ((bp->b_flags & B_INVAL) || !(bp->b_flags & B_DELWRI))
- bufcountwakeup(bp);
+ bufcountwakeup();
/*
* Something we can maybe free or reuse.
@@ -1941,8 +1922,6 @@ restart:
bp->b_flags = 0;
bp->b_ioflags = 0;
bp->b_xflags = 0;
- KASSERT((bp->b_vflags & BV_INFREECNT) == 0,
- ("buf %p still counted as free?", bp));
bp->b_vflags = 0;
bp->b_vp = NULL;
bp->b_blkno = bp->b_lblkno = 0;
@@ -4104,27 +4083,4 @@ DB_SHOW_COMMAND(vnodebufs, db_show_vnode
db_printf("\n");
}
}
-
-DB_COMMAND(countfreebufs, db_coundfreebufs)
-{
- struct buf *bp;
- int i, used = 0, nfree = 0;
-
- if (have_addr) {
- db_printf("usage: countfreebufs\n");
- return;
- }
-
- for (i = 0; i < nbuf; i++) {
- bp = &buf[i];
- if ((bp->b_vflags & BV_INFREECNT) != 0)
- nfree++;
- else
- used++;
- }
-
- db_printf("Counted %d free, %d used (%d tot)\n", nfree, used,
- nfree + used);
- db_printf("numfreebuffers is %d\n", numfreebuffers);
-}
#endif /* DDB */
Modified: stable/7/sys/sys/buf.h
==============================================================================
--- stable/7/sys/sys/buf.h Wed Sep 15 15:18:41 2010 (r212663)
+++ stable/7/sys/sys/buf.h Wed Sep 15 15:33:51 2010 (r212664)
@@ -247,7 +247,6 @@ struct buf {
#define BV_SCANNED 0x00000001 /* VOP_FSYNC funcs mark written
bufs */
#define BV_BKGRDINPROG 0x00000002 /* Background write in progress
*/
#define BV_BKGRDWAIT 0x00000004 /* Background write waiting */
-#define BV_INFREECNT 0x80000000 /* buf is counted in
numfreebufs */
#ifdef _KERNEL
/*
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