diff options
Diffstat (limited to 'sys/kern/vfs_bio.c')
-rw-r--r-- | sys/kern/vfs_bio.c | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/sys/kern/vfs_bio.c b/sys/kern/vfs_bio.c index 96c8442..6393399 100644 --- a/sys/kern/vfs_bio.c +++ b/sys/kern/vfs_bio.c @@ -206,6 +206,9 @@ SYSCTL_INT(_vfs, OID_AUTO, flushbufqtarget, CTLFLAG_RW, &flushbufqtarget, 0, static long notbufdflashes; SYSCTL_LONG(_vfs, OID_AUTO, notbufdflashes, CTLFLAG_RD, ¬bufdflashes, 0, "Number of dirty buffer flushes done by the bufdaemon helpers"); +static long barrierwrites; +SYSCTL_LONG(_vfs, OID_AUTO, barrierwrites, CTLFLAG_RW, &barrierwrites, 0, + "Number of barrier writes"); /* * Wakeup point for bufdaemon, as well as indicator of whether it is already @@ -888,6 +891,9 @@ bufwrite(struct buf *bp) return (0); } + if (bp->b_flags & B_BARRIER) + barrierwrites++; + oldflags = bp->b_flags; BUF_ASSERT_HELD(bp); @@ -1007,6 +1013,8 @@ bdwrite(struct buf *bp) CTR3(KTR_BUF, "bdwrite(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags); KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp)); + KASSERT((bp->b_flags & B_BARRIER) == 0, + ("Barrier request in delayed write %p", bp)); BUF_ASSERT_HELD(bp); if (bp->b_flags & B_INVAL) { @@ -1167,6 +1175,40 @@ bawrite(struct buf *bp) } /* + * babarrierwrite: + * + * Asynchronous barrier write. Start output on a buffer, but do not + * wait for it to complete. Place a write barrier after this write so + * that this buffer and all buffers written before it are committed to + * the disk before any buffers written after this write are committed + * to the disk. The buffer is released when the output completes. + */ +void +babarrierwrite(struct buf *bp) +{ + + bp->b_flags |= B_ASYNC | B_BARRIER; + (void) bwrite(bp); +} + +/* + * bbarrierwrite: + * + * Synchronous barrier write. Start output on a buffer and wait for + * it to complete. Place a write barrier after this write so that + * this buffer and all buffers written before it are committed to + * the disk before any buffers written after this write are committed + * to the disk. The buffer is released when the output completes. + */ +int +bbarrierwrite(struct buf *bp) +{ + + bp->b_flags |= B_BARRIER; + return (bwrite(bp)); +} + +/* * bwillwrite: * * Called prior to the locking of any vnodes when we are expecting to |