[LU-9724] update ext4-large-eas.patch to match upstream ext4 feature

• Status: Resolved
• Project: Lustre
• Affects Version/s: Lustre 2.5.0, Lustre 2.7.0
• Fix Version/s: Lustre 2.11.0
• Type: Task
• Priority: Major
• Reporter: Andreas Dilger
• Assignee: Emoly Liu
• Resolution: Fixed

Description

In order to match the enhanced ea_inode functionality being landed to the upstream ext4 kernel tree, we need to modify our ext4-large-eas.patch and e2fsprogs patches to start properly initializing some of the fields we don't currently use to minimize the interoperability issues.

In particular, the new EA inode refcount should be initialized to 1, and hash field should be computed based on the xattr value as it is in the upstream kernel patch. We don't need to backport any of the xattr sharing functionality, since Lustre never shares large xattrs as the lov and link xattrs are always unique. This can be landed to master for the 2.11 release, and possibly included into 2.10.1 or later maintenance release.

For e2fsck we should set the EA inode refcount = 1 and set the hash on large xattrs that are found during scanning and are otherwise valid. This should be done in a manner that is not alarming to existing users, such as printing a fix_problem() message like:
noformat
Found old-style Lustre large xattr inode(s) without refcount or hash. Fix?
noformat
and then together with something like PR_1_SUPPRESS_MESSAGES and a new PR_LATCH_EA_INODE it should prompt and save the answer to re-use it when repairing all such large xattrs rather than prompting to repair each one (which might be millions of files on a large filesystem with many stripes).

Issue Links

• is related to: LU-6220 push ext4/ldiskfs patches upstream if...
• is related to: LU-1732 enable wide striping by default
• is related to: LU-9723 test large xattr (ea_inode) patch int...
• is related to: LU-908 multi-block xattr support

Comments

[Emoly Liu]

Andreas,
I check the upstream ext4 kernel and want to make sure if the following code from ext4_xattr_inode_create() needs to be changed to ldiskfs kernel:

	if (!IS_ERR(ea_inode)) {
		...
		ext4_xattr_inode_set_ref(ea_inode, 1);
		ext4_xattr_inode_set_hash(ea_inode, hash);
		...
        }

And all the kernel series need this change?

Thanks,
Emoly

[Gerrit Updater]

Emoly Liu ([e-mail]) uploaded a new patch: https://review.whamcloud.com/31033
Subject: LU-9724 ldiskfs: update ext4-large-eas.patch to match upstream ext4
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: fc12bcaa392da4d5ea2e28d61ef0be42d5367193

[Gerrit Updater]

Oleg Drokin ([e-mail]) merged in patch https://review.whamcloud.com/31033/
Subject: LU-9724 ldiskfs: update ext4-large-eas.patch to match upstream ext4
Project: fs/lustre-release
Branch: master
Current Patch Set:
Commit: 8c8f4920e0157b2f1617b7d6da3f758781d68642

[Peter Jones]

Landed for 2.11