[LU-14826] enable striped directory as NFS export

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.15.0
• Severity: 3
• Assignee: Lai Siyao
• Reporter: Lai Siyao

Description

Striped directory as NFS export is not supported, because ".." lookup for subdir under striped directory returns stripe FID back, other than the directory master object FID, while ll_get_parent() needs the latter for NFS.

Issue Links

• is related to: LU-15835 sanityn test_102: [20108.951589] WARNING: CPU: 1 PID: 722753 at fs/exportfs/expfs.c:96 reconnect_path+0x22b/0x2c0
• is related to: LU-14823 re-enable open-by-handle tests
• is related to: LU-15617 Add shellcheck to prepare-commit-msg

Comments

[Gerrit Updater]

"Oleg Drokin <[e-mail]>" merged in patch https://review.whamcloud.com/46693/
Subject: LU-14826 tests: fix sanityn.sh test_102 version check
Project: fs/lustre-release
Branch: master
Current Patch Set:
Commit: b9d93dc33e24718c316b84baa89282bebe05a546

[Gerrit Updater]

"Andreas Dilger <[e-mail]>" uploaded a new patch: https://review.whamcloud.com/46693
Subject: LU-14826 tests: fix sanityn.sh test_102 version check
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: 32768318819952b670ac778bfba14e3fdb82c04e

[Peter Jones]

Landed for 2.15

[Gerrit Updater]

Oleg Drokin ([e-mail]) merged in patch https://review.whamcloud.com/44168/
Subject: LU-14826 mdt: getattr_name("..") under striped directory
Project: fs/lustre-release
Branch: master
Current Patch Set:
Commit: cbc62b0b829afdceaa01820996e567b5bdeb281c

[Lai Siyao]

It's not lookup("master/substripe/.."), but lookup("master/substripe/subdir/.."), herein if "subdir" is a plain directory, it will fail too.

[Andreas Dilger]

I was just coming to the same conclusion. What happens is that the client finds the directory X layout is striped, hashes "..", and finds the sub-stripe of the directory, and does a lookup of ".." in the sub-stripe directory. That ends up returning the FID of directory X again, since it is the parent of the sub-stripe.

Rather than adding complexity to the MDS to handle this case, what about having the client check for lookup of ".." and not do the sub-stripe lookup, but rather do the ".." lookup in the master object FID? That should return the proper parent FID, rather than looking up master/substripe/.. == master?

[Gerrit Updater]

Lai Siyao ([e-mail]) uploaded a new patch: https://review.whamcloud.com/44168
Subject: LU-14826 mdt: lookup("..") under striped directory
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: b798c073281f4e20f955fefaf8109920f9d5b75c