[PATCH 5/6] xfs: disable noattr2/attr2 mount options for CRC enabled filesystems

Dave Chinner
2013-06-03T05:29:26Z

From: Dave Chinner <dchinner@redhat.com>

attr2 format is always enabled for v5 superblock filesystems, so the
mount options to enable or disable it need to be cause mount errors.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
Documentation/filesystems/xfs.txt | 3 +++
fs/xfs/xfs_super.c | 11 +++++++++++
2 files changed, 14 insertions(+)

diff --git a/Documentation/filesystems/xfs.txt b/Documentation/filesystems/xfs.txt
index 3e4b3dd..83577f0 100644
--- a/Documentation/filesystems/xfs.txt
+++ b/Documentation/filesystems/xfs.txt
@@ -33,6 +33,9 @@ When mounting an XFS filesystem, the following options are accepted.
removing extended attributes) the on-disk superblock feature
bit field will be updated to reflect this format being in use.

+ CRC enabled filesystems always use the attr2 format, and so
+ will reject the noattr2 mount option if it is set.
+
barrier
Enables the use of block layer write barriers for writes into
the journal and unwritten extent conversion. This allows for
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index ea341ce..f62abb2 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -1373,6 +1373,17 @@ xfs_finish_flags(
}

/*
+ * CRC enabled filesystems always use attr2 format for attributes.
+ */
+ if (xfs_sb_version_hascrc(&mp->m_sb) &&
+ (mp->m_flags & XFS_MOUNT_NOATTR2)) {
+ xfs_warn(mp,
+"Cannot mount a V5 filesystems as %s. %s is always enabled for v5 filesystems.",
+ MNTOPT_NOATTR2, MNTOPT_ATTR2);
+ return XFS_ERROR(EINVAL);
+ }
+
+ /*
* mkfs'ed attr2 will turn on attr2 mount unless explicitly
* told by noattr2 to turn it off
*/
--
1.7.10.4