[LU-17740] enable 'user_xattr' and 'acl' on MDT by default

• Type: Improvement
• Resolution: Unresolved
• Priority: Minor
• Affects Version/s: Lustre 2.14.0, Lustre 2.16.0
• Labels: usability
• Severity: 3
• Assignee: WC Triage
• Reporter: Andreas Dilger

Description

The "user_xattr" and "acl" filesystem mount options have been enabled by default in ext4 since the 2.6.32 kernels (RHEL6.x), but they are still required to enable xattrs and ACLs on the MDTs.

However, it has also been standard for mkfs.lustre to specify these mount options as defaults on the MDT as far back as Git history goes (1.5.x), so there is virtually no reason not to make them the internal MDT defaults as well, unless "nouser_xattr" or "noacl" are specified. These negative options have been deprecated and non-functional for ext4 since 3.5 kernels (RHEL7.x), removed from ext4 in 6.0 kernels, so they should eventually be removed from Lustre as well. That should be deferred for a long time since all existing filesystems will still have them as persistent mount options, and would fail if they are removed.