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-rw-r--r--fs/xfs/linux-2.6/xfs_buf.c35
1 files changed, 16 insertions, 19 deletions
diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c
index aa1d353def2..4c5deb6e9e3 100644
--- a/fs/xfs/linux-2.6/xfs_buf.c
+++ b/fs/xfs/linux-2.6/xfs_buf.c
@@ -488,29 +488,16 @@ found:
spin_unlock(&pag->pag_buf_lock);
xfs_perag_put(pag);
- /* Attempt to get the semaphore without sleeping,
- * if this does not work then we need to drop the
- * spinlock and do a hard attempt on the semaphore.
- */
- if (down_trylock(&bp->b_sema)) {
+ if (xfs_buf_cond_lock(bp)) {
+ /* failed, so wait for the lock if requested. */
if (!(flags & XBF_TRYLOCK)) {
- /* wait for buffer ownership */
xfs_buf_lock(bp);
XFS_STATS_INC(xb_get_locked_waited);
} else {
- /* We asked for a trylock and failed, no need
- * to look at file offset and length here, we
- * know that this buffer at least overlaps our
- * buffer and is locked, therefore our buffer
- * either does not exist, or is this buffer.
- */
xfs_buf_rele(bp);
XFS_STATS_INC(xb_busy_locked);
return NULL;
}
- } else {
- /* trylock worked */
- XB_SET_OWNER(bp);
}
if (bp->b_flags & XBF_STALE) {
@@ -876,10 +863,18 @@ xfs_buf_rele(
*/
/*
- * Locks a buffer object, if it is not already locked.
- * Note that this in no way locks the underlying pages, so it is only
- * useful for synchronizing concurrent use of buffer objects, not for
- * synchronizing independent access to the underlying pages.
+ * Locks a buffer object, if it is not already locked. Note that this in
+ * no way locks the underlying pages, so it is only useful for
+ * synchronizing concurrent use of buffer objects, not for synchronizing
+ * independent access to the underlying pages.
+ *
+ * If we come across a stale, pinned, locked buffer, we know that we are
+ * being asked to lock a buffer that has been reallocated. Because it is
+ * pinned, we know that the log has not been pushed to disk and hence it
+ * will still be locked. Rather than continuing to have trylock attempts
+ * fail until someone else pushes the log, push it ourselves before
+ * returning. This means that the xfsaild will not get stuck trying
+ * to push on stale inode buffers.
*/
int
xfs_buf_cond_lock(
@@ -890,6 +885,8 @@ xfs_buf_cond_lock(
locked = down_trylock(&bp->b_sema) == 0;
if (locked)
XB_SET_OWNER(bp);
+ else if (atomic_read(&bp->b_pin_count) && (bp->b_flags & XBF_STALE))
+ xfs_log_force(bp->b_target->bt_mount, 0);
trace_xfs_buf_cond_lock(bp, _RET_IP_);
return locked ? 0 : -EBUSY;