[PATCH] xfs: clarify lock ordering comment

[Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx>]

Replace "i_mmap_lock" with "mmap_lock" in the lock ordering comment above
xfs_filemap_page_mkwrite().  The lock in question is actually the
XFS_MMAPLOCK_SHARED rw_semaphore (no leading "i"), and this comment is
easily confused with the "i_mmap_lock_[read|write]" functions that operate
on struct address_space->i_mmap_rwsem.  This clarification is especially
important because address_space->i_mmap_rwsem is taken down in the DAX
code as part of this fault path.

Signed-off-by: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx>
---
 fs/xfs/xfs_file.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index f429662..b190033 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -1477,7 +1477,7 @@ xfs_file_llseek(
  *
  * mmap_sem (MM)
  *   sb_start_pagefault(vfs, freeze)
- *     i_mmap_lock (XFS - truncate serialisation)
+ *     mmap_lock (XFS - truncate serialisation)
  *       page_lock (MM)
  *         i_lock (XFS - extent map serialisation)
  */
-- 
2.1.0