---

yaml
---
r: 109901
b: refs/heads/master
c: f9114eb
h: refs/heads/master
i:
  109899: a20753a
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: b5b8c9acd547244eb2b7d0280ba38b9dd01971cc
+refs/heads/master: f9114eba1eb08ee75fd0f1eee780f0290fb3c043

trunk/fs/xfs/xfs_dfrag.c

@@ -149,7 +149,14 @@ xfs_swap_extents(
 
 	sbp = &sxp->sx_stat;
 
-	xfs_lock_two_inodes(ip, tip, lock_flags);
+	/*
+	 * we have to do two separate lock calls here to keep lockdep
+	 * happy. If we try to get all the locks in one call, lock will
+	 * report false positives when we drop the ILOCK and regain them
+	 * below.
+	 */
+	xfs_lock_two_inodes(ip, tip, XFS_IOLOCK_EXCL);
+	xfs_lock_two_inodes(ip, tip, XFS_ILOCK_EXCL);
 	locked = 1;
 
 	/* Verify that both files have the same format */

trunk/fs/xfs/xfs_vnodeops.c

@@ -1838,6 +1838,12 @@ xfs_lock_inodes(
 #endif
 }
 
+/*
+ * xfs_lock_two_inodes() can only be used to lock one type of lock
+ * at a time - the iolock or the ilock, but not both at once. If
+ * we lock both at once, lockdep will report false positives saying
+ * we have violated locking orders.
+ */
 void
 xfs_lock_two_inodes(
 	xfs_inode_t		*ip0,
@@ -1848,6 +1854,8 @@ xfs_lock_two_inodes(
 	int			attempts = 0;
 	xfs_log_item_t		*lp;
 
+	if (lock_mode & (XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL))
+		ASSERT((lock_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL)) == 0);
 	ASSERT(ip0->i_ino != ip1->i_ino);
 
 	if (ip0->i_ino > ip1->i_ino) {