The MS_I_VERSION mount flag is exposed via the VFS, as documented in the mount manpages etc; see the iversion and noiversion mount options in mount(8). As a result, mount -o remount looks for this option in /proc/mounts and will only send the I_VERSION flag back in during remount it it is present. Since it's not there, a remount will /remove/ the I_VERSION flag at the vfs level, and iversion functionality is lost. xfs v5 superblocks intend to always have i_version enabled; it is set as a default at mount time, but is lost during remount for the reasons above. The generic fix would be to expose this documented option in /proc/mounts, but since that was rejected, fix it up again in the xfs remount path instead, so that at least xfs won't suffer from this misbehavior. Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx> -- diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c index 379cbff438bc..9239985571af 100644 --- a/fs/xfs/xfs_super.c +++ b/fs/xfs/xfs_super.c @@ -1714,6 +1714,10 @@ xfs_fc_reconfigure( int flags = fc->sb_flags; int error; + /* version 5 superblocks always support version counters. */ + if (XFS_SB_VERSION_NUM(&mp->m_sb) == XFS_SB_VERSION_5) + fc->sb_flags |= SB_I_VERSION; + error = xfs_fc_validate_params(new_mp); if (error) return error;