Merge branch 'rmobile/ag5' into rmobile-latest

1 files changed, 7 insertions, 1 deletions

diff --git a/fs/xfs/xfs_filestream.c b/fs/xfs/xfs_filestream.c
index 9b715dce5699..9124425b7f2f 100644
--- a/fs/xfs/xfs_filestream.c
+++ b/fs/xfs/xfs_filestream.c
@@ -744,9 +744,15 @@ xfs_filestream_new_ag(
          * If the file's parent directory is known, take its iolock in exclusive
          * mode to prevent two sibling files from racing each other to migrate
          * themselves and their parent to different AGs.
+         *
+         * Note that we lock the parent directory iolock inside the child
+         * iolock here.  That's fine as we never hold both parent and child
+         * iolock in any other place.  This is different from the ilock,
+         * which requires locking of the child after the parent for namespace
+         * operations.
          */
         if (pip)
-                xfs_ilock(pip, XFS_IOLOCK_EXCL);
+                xfs_ilock(pip, XFS_IOLOCK_EXCL | XFS_IOLOCK_PARENT);
 
         /*
          * A new AG needs to be found for the file.  If the file's parent