diff options
Diffstat (limited to 'sys/kern/vfs_bio.c')
| -rw-r--r-- | sys/kern/vfs_bio.c | 57 |
1 files changed, 39 insertions, 18 deletions
diff --git a/sys/kern/vfs_bio.c b/sys/kern/vfs_bio.c index 630456a512b..e088c881714 100644 --- a/sys/kern/vfs_bio.c +++ b/sys/kern/vfs_bio.c @@ -1,4 +1,4 @@ -/* $OpenBSD: vfs_bio.c,v 1.38 2001/05/05 20:57:01 art Exp $ */ +/* $OpenBSD: vfs_bio.c,v 1.39 2001/08/30 12:38:52 gluk Exp $ */ /* $NetBSD: vfs_bio.c,v 1.44 1996/06/11 11:15:36 pk Exp $ */ /*- @@ -107,6 +107,7 @@ struct bio_ops bioops; static __inline struct buf *bio_doread __P((struct vnode *, daddr_t, int, struct ucred *, int)); int count_lock_queue __P((void)); +int getnewbuf __P((int slpflag, int slptimeo, struct buf **)); /* * We keep a few counters to monitor the utilization of the buffer cache @@ -678,7 +679,7 @@ getblk(vp, blkno, size, slpflag, slptimeo) int size, slpflag, slptimeo; { struct bufhashhdr *bh; - struct buf *bp; + struct buf *bp, *nbp = NULL; int s, err; /* @@ -719,13 +720,17 @@ start: } if (bp == NULL) { - if ((bp = getnewbuf(slpflag, slptimeo)) == NULL) + if (nbp == NULL && getnewbuf(slpflag, slptimeo, &nbp) != 0) { goto start; + } + bp = nbp; binshash(bp, bh); bp->b_blkno = bp->b_lblkno = blkno; s = splbio(); bgetvp(vp, bp); splx(s); + } else if (nbp != NULL) { + brelse(nbp); } allocbuf(bp, size); @@ -741,8 +746,7 @@ geteblk(size) { struct buf *bp; - while ((bp = getnewbuf(0, 0)) == 0) - ; + getnewbuf(0, 0, &bp); SET(bp->b_flags, B_INVAL); binshash(bp, &invalhash); allocbuf(bp, size); @@ -783,8 +787,7 @@ allocbuf(bp, size) int amt; /* find a buffer */ - while ((nbp = getnewbuf(0, 0)) == NULL) - ; + getnewbuf(0, 0, &nbp); SET(nbp->b_flags, B_INVAL); binshash(nbp, &invalhash); @@ -844,13 +847,21 @@ out: * Find a buffer which is available for use. * Select something from a free list. * Preference is to AGE list, then LRU list. + * + * We must notify getblk if we slept during the buffer allocation. When + * that happens, we allocate a buffer anyway (unless tsleep is interrupted + * or times out) and return !0. */ -struct buf * -getnewbuf(slpflag, slptimeo) +int +getnewbuf(slpflag, slptimeo, bpp) int slpflag, slptimeo; + struct buf **bpp; { - register struct buf *bp; - int s; + struct buf *bp; + int s, ret, error; + + *bpp = NULL; + ret = 0; start: s = splbio(); @@ -863,18 +874,25 @@ start: if ((numcleanbufs <= locleanbufs) && curproc != syncerproc) { /* wait for a free buffer of any kind */ needbuffer++; - tsleep(&needbuffer, slpflag|(PRIBIO+1), "getnewbuf", slptimeo); + error = tsleep(&needbuffer, slpflag|(PRIBIO+1), "getnewbuf", + slptimeo); splx(s); - return (0); + if (error) + return (1); + ret = 1; + goto start; } if ((bp = bufqueues[BQ_AGE].tqh_first) == NULL && (bp = bufqueues[BQ_LRU].tqh_first) == NULL) { /* wait for a free buffer of any kind */ syncer_needbuffer = 1; - tsleep(&syncer_needbuffer, slpflag|(PRIBIO-3), "getnewbuf", - slptimeo); + error = tsleep(&syncer_needbuffer, slpflag|(PRIBIO-3), + "getnewbuf", slptimeo); splx(s); - return (0); + if (error) + return (1); + ret = 1; + goto start; } bremfree(bp); @@ -903,7 +921,9 @@ start: */ SET(bp->b_flags, B_AGE); bawrite(bp); - return (0); + /* bawrite can sleep, return 1 */ + ret = 1; + goto start; } /* disassociate us from our vnode, if we had one... */ @@ -937,7 +957,8 @@ start: } bremhash(bp); - return (bp); + *bpp = bp; + return (ret); } /* |