[LU-11568] Get rid of SLAB_DESTROY_BY_RCU

• Type: Bug
• Resolution: Fixed
• Priority: Critical
• Fix Version/s: Lustre 2.13.0, Lustre 2.12.1
• Affects Version/s: Lustre 2.13.0
• Severity: 3
• Assignee: Oleg Drokin
• Reporter: Oleg Drokin

Description

This code was introduced by bz 18015 https://bugzilla.lustre.org/show_bug.cgi?id=18015

Newer kernels rename that symbol and it's not used anyway, but also at least in RHEL 7.[345] there's bug in this functionality htat leads to use after frees that are seen prominently in our nfs testing in maloo (in addition to my testrig). See LU-11063.
Example nfs failures:
https://testing.whamcloud.com/test_sessions/1cd5592c-8319-4aa7-aa2b-4549a83ce9cd
https://testing.whamcloud.com/test_sessions/9e6c8dec-d1dd-4ad4-b028-f98b5fdf63a9

Anyway after reviewing the original patch I think we just need to get rid of this flag altogether and if the rapid load/unload is still a problem, work it around in some better more robust way.

Issue Links

• is related to: LU-11063 RHEL7.[345] RCU breakage

Comments

[Gerrit Updater]

Andreas Dilger ([e-mail]) uploaded a new patch: https://review.whamcloud.com/35018
Subject: LU-11568 ldlm: Remove use of SLAB_DESTROY_BY_RCU for ldlm lock slab
Project: fs/lustre-release
Branch: b2_10
Current Patch Set: 1
Commit: 537c25bbd9a90a198ab464ec2fd67d29b7cbe591

[Gerrit Updater]

Oleg Drokin ([e-mail]) merged in patch https://review.whamcloud.com/34434/
Subject: LU-11568 ldlm: Remove use of SLAB_DESTROY_BY_RCU for ldlm lock slab
Project: fs/lustre-release
Branch: b2_12
Current Patch Set:
Commit: f60637d9379df8c1e9aabf2f8639e8e318489a4d

[Gerrit Updater]

Oleg Drokin ([e-mail]) uploaded a new patch: https://review.whamcloud.com/34434
Subject: LU-11568 ldlm: Remove use of SLAB_DESTROY_BY_RCU for ldlm lock slab
Project: fs/lustre-release
Branch: b2_12
Current Patch Set: 1
Commit: 2f34a93ec495254cb69a00d58e9b53c96be86054

[Peter Jones]

Landed for 2.13

[Gerrit Updater]

Oleg Drokin ([e-mail]) merged in patch https://review.whamcloud.com/34147/
Subject: LU-11568 ldlm: Remove use of SLAB_DESTROY_BY_RCU for ldlm lock slab
Project: fs/lustre-release
Branch: master
Current Patch Set:
Commit: 82d014e71e14671e876055851a0d37e98b4cc079

[Gerrit Updater]

Oleg Drokin ([e-mail]) uploaded a new patch: https://review.whamcloud.com/34147
Subject: LU-11568 ldlm: Remove use of SLAB_DESTROY_BY_RCU for ldlm lock slab
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: 07d0c94f6a6c7b86cd7e738d368cfbcbff3f42b5