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;