1 files changed, 9 insertions, 0 deletions

diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c
index f01de3c55c43..649ade8ef598 100644
--- a/fs/xfs/linux-2.6/xfs_buf.c
+++ b/fs/xfs/linux-2.6/xfs_buf.c
@@ -37,6 +37,7 @@
 
 #include "xfs_sb.h"
 #include "xfs_inum.h"
+#include "xfs_log.h"
 #include "xfs_ag.h"
 #include "xfs_dmapi.h"
 #include "xfs_mount.h"
@@ -850,6 +851,12 @@ xfs_buf_lock_value(
  *      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 sleeping until someone
+ *      else pushes the log, push it ourselves before trying to get the lock.
  */
 void
 xfs_buf_lock(
@@ -857,6 +864,8 @@ xfs_buf_lock(
 {
         trace_xfs_buf_lock(bp, _RET_IP_);
 
+        if (atomic_read(&bp->b_pin_count) && (bp->b_flags & XBF_STALE))
+                xfs_log_force(bp->b_mount, 0);
         if (atomic_read(&bp->b_io_remaining))
                 blk_run_address_space(bp->b_target->bt_mapping);
         down(&bp->b_sema);