[xfs-masters] [patch] xfs: bitlock fix

[Nick Piggin <npiggin@xxxxxxx>]

XFS's xfs_icsb_unlock_cntr is missing a memory barrier to close the critical
section. Use lock bitops for this.

Signed-off-by: Nick Piggin <npiggin@xxxxxxx>
---
Index: linux-2.6/fs/xfs/xfs_mount.c
===================================================================
--- linux-2.6.orig/fs/xfs/xfs_mount.c
+++ linux-2.6/fs/xfs/xfs_mount.c
@@ -2035,7 +2035,7 @@ STATIC_INLINE void
 xfs_icsb_lock_cntr(
        xfs_icsb_cnts_t *icsbp)
 {
-       while (test_and_set_bit(XFS_ICSB_FLAG_LOCK, &icsbp->icsb_flags)) {
+       while (test_and_set_bit_lock(XFS_ICSB_FLAG_LOCK, &icsbp->icsb_flags)) {
                ndelay(1000);
        }
 }
@@ -2044,7 +2044,7 @@ STATIC_INLINE void
 xfs_icsb_unlock_cntr(
        xfs_icsb_cnts_t *icsbp)
 {
-       clear_bit(XFS_ICSB_FLAG_LOCK, &icsbp->icsb_flags);
+       clear_bit_unlock(XFS_ICSB_FLAG_LOCK, &icsbp->icsb_flags);
 }