[LU-13582] open/rmdir/close vs xattr set race may cause a transaction exec abort

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.17.0
• Severity: 3
• Assignee: Alexander Zarochentsev
• Reporter: Alexander Zarochentsev

Description

An attempt to close a file handle to an ophan striped dir may race with a delayed xattr set or just an chrown. Due to lacking of DLM locks for mdt_close(), the race is not prevented by LDLM and only gets resolved at transaction exec phase. For a striped dir , the xattr set itransaction is a distributed operation, its rollback is complex, potentially buggy, and should be avoided if it is possible.

The following errors indicate an tx exec error:

/tmp/test_logs/1589821660/sanityn.test_107.debug_log.devvm1.1589821723.log:00000020:00000040:1.0:1589821723.399086:0:14322:0:(out_lib.c:752:out_tx_xattr_set_exec()) lustre-MDT0002-osd: set xattr buf ffff8d9e52e05548 name user.17 flag 0
/tmp/test_logs/1589821660/sanityn.test_107.debug_log.devvm1.1589821723.log:00000020:02000000:1.0:1589821723.399089:0:14322:0:(out_lib.c:756:out_tx_xattr_set_exec()) No object found [0x280000402:0x2:0x0]
/tmp/test_logs/1589821660/sanityn.test_107.debug_log.devvm1.1589821723.log:00000020:00000001:1.0:1589821723.399098:0:14322:0:(out_lib.c:843:out_tx_xattr_set_exec()) Process leaving via out (rc=18446744073709551614 : -2 : 0xfffffffffffffffe)
/tmp/test_logs/1589821660/sanityn.test_107.debug_log.devvm1.1589821723.log:00000020:00000040:1.0:1589821723.399100:0:14322:0:(out_lib.c:847:out_tx_xattr_set_exec()) lustre-MDT0002-osd: insert xattr set reply ffff8d9de08361e0 index 0: rc = -2

I got them by a reproducer I will post later.

Comments

[Peter Jones]

Merged for 2.17

[Gerrit Updater]

"Oleg Drokin <[e-mail]>" merged in patch https://review.whamcloud.com/c/fs/lustre-release/+/53891/
Subject: LU-13582 out: make tx abort verbose
Project: fs/lustre-release
Branch: master
Current Patch Set:
Commit: c9042de70e93159c02bd94f5b2d92c27157767cb

[Gerrit Updater]

"Alexander Zarochentsev <[e-mail]>" uploaded a new patch: https://review.whamcloud.com/c/fs/lustre-release/+/53891
Subject: LU-13582 dne: make tx abort verbose
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: 6eb98aef2d7fffa6ff84d33130484f2386429264

[Gerrit Updater]

Alexander Zarochentsev ([e-mail]) uploaded a new patch: https://review.whamcloud.com/38652
Subject: LU-13582 tests: reproducer
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: 5e829eb0636e62bd99480a28a61574954517009a