xfs: lockdep annotations for xfs_dqlock2
xfs_dqlock2 locks two xfs_dquots, which is fine as it always locks the
dquot with the lower id first. Use mutex_lock_nested to tell lockdep
about this fact.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
diff --git a/fs/xfs/quota/xfs_dquot.h b/fs/xfs/quota/xfs_dquot.h
index 7e455337..d443e93 100644
--- a/fs/xfs/quota/xfs_dquot.h
+++ b/fs/xfs/quota/xfs_dquot.h
@@ -97,6 +97,16 @@
#define dq_hashlist q_lists.dqm_hashlist
#define dq_flags q_lists.dqm_flags
+/*
+ * Lock hierachy for q_qlock:
+ * XFS_QLOCK_NORMAL is the implicit default,
+ * XFS_QLOCK_NESTED is the dquot with the higher id in xfs_dqlock2
+ */
+enum {
+ XFS_QLOCK_NORMAL = 0,
+ XFS_QLOCK_NESTED,
+};
+
#define XFS_DQHOLD(dqp) ((dqp)->q_nrefs++)
#ifdef DEBUG