xfs.5: document barrier deprecation in xfs

Since kernel v4.10, the barrier mount option is deprecated:

2291dab2 xfs: Always flush caches when integrity is required
4cf4573d xfs: deprecate barrier/nobarrier mount option

Document this fact in the xfs(5) manpage.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
1 file changed