[XFS] Fix up noattr2 so that it will properly update the versionnum and

features2 fields.

Previously, mounting with noattr2 failed to achieve anything because
although it cleared the attr2 mount flag, it would set it again as soon as
it processed the superblock fields. The fix now has an explicit noattr2
flag and uses it later to fix up the versionnum and features2 fields.

SGI-PV: 980021
SGI-Modid: xfs-linux-melb:xfs-kern:31003a

Signed-off-by: Tim Shimmin <tes@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>

1 files changed, 11 insertions, 1 deletions

diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index da3988453b71..361c7a755a07 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -994,9 +994,19 @@ xfs_mountfs(
                  * Re-check for ATTR2 in case it was found in bad_features2
                  * slot.
                  */
-                if (xfs_sb_version_hasattr2(&mp->m_sb))
+                if (xfs_sb_version_hasattr2(&mp->m_sb) &&
+                   !(mp->m_flags & XFS_MOUNT_NOATTR2))
                         mp->m_flags |= XFS_MOUNT_ATTR2;
+        }
+
+        if (xfs_sb_version_hasattr2(&mp->m_sb) &&
+           (mp->m_flags & XFS_MOUNT_NOATTR2)) {
+                xfs_sb_version_removeattr2(&mp->m_sb);
+                update_flags |= XFS_SB_FEATURES2;
 
+                /* update sb_versionnum for the clearing of the morebits */
+                if (!sbp->sb_features2)
+                        update_flags |= XFS_SB_VERSIONNUM;
         }
 
         /*