[LU-19576] Oops in lprocfs_stats_seq_show()

• Type: Bug
• Resolution: Unresolved
• Priority: Medium
• Severity: 3
• Assignee: WC Triage
• Reporter: Alex Zhuravlev

Description

[674018.786829] Lustre: server umount testfs-MDT0002 complete
[674104.901149] BUG: unable to handle kernel paging request at ffffffffc1831159
[674104.902703] PGD 1543812067 P4D 1543813067 PUD 1543815067 PMD 10f781067 PTE 0
[674104.904158] Oops: 0000 [#1] SMP NOPTI
[674104.905015] CPU: 6 PID: 2442172 Comm: lctl Kdump: loaded Tainted: G           OE     -------- -  - 4.18.0-553.71.1.el8_lustre.ddn17.x86_64 #1
[674104.907158] Hardware name: DDN SFA400NVX2E, BIOS 1.16.3-20250916_202628-co-sf-pe-221 04/01/2014
[674104.908728] RIP: 0010:string_nocheck+0x12/0x70
[674104.909682] Code: ef e8 72 a6 00 00 4c 01 e3 e9 7a ff ff ff 66 2e 0f 1f 84 00 00 00 00 00 49 89 f2 48 89 ce 48 89 f8 48 c1 fe 30 66 85 f6 74 4f <44> 0f b6 0a 45 84 c9 74 46 83 ee 01 41 b8 01 00 00 00 48 8d 7c 37
[674104.912971] RSP: 0018:ff4e339ae0287d08 EFLAGS: 00010286
[674104.914038] RAX: ff47b8f4e161d0aa RBX: ff47b8f4e161e000 RCX: ffff0a0200001904
[674104.915378] RDX: ffffffffc1831159 RSI: ffffffffffffffff RDI: ff47b8f4e161d0aa
[674104.916715] RBP: ffffffffc1831159 R08: 0000000000000f56 R09: 00000001763c5f78
[674104.917934] R10: ff47b8f4e161e000 R11: ff47b8f4e161d09e R12: ffff0a0200001904
[674104.919231] R13: ffffffffc1001ac8 R14: 0000000000000f56 R15: ffffffffc1001ac8
[674104.920567] FS:  00007fa2d4a0c740(0000) GS:ff47b90cf1780000(0000) knlGS:0000000000000000
[674104.922040] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[674104.923172] CR2: ffffffffc1831159 CR3: 0000000314ca0003 CR4: 0000000000771ee0
[674104.924491] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[674104.925824] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[674104.927148] PKRU: 55555554
[674104.927830] Call Trace:
[674104.928471]  ? __die_body+0x1a/0x60
[674104.929256]  ? no_context+0x1ba/0x3f0
[674104.930042]  ? __bad_area_nosemaphore+0x157/0x180
[674104.930999]  ? do_page_fault+0x37/0x12d
[674104.931820]  ? page_fault+0x1e/0x30
[674104.932586]  ? string_nocheck+0x12/0x70
[674104.933400]  string+0x44/0x60
[674104.934081]  vsnprintf+0x340/0x520
[674104.934809]  seq_vprintf+0x34/0x50
[674104.935551]  seq_printf+0x53/0x70
[674104.936280]  lprocfs_stats_seq_show+0x8d/0x120 [obdclass]
[674104.937365]  seq_read+0x303/0x420
[674104.938083]  proc_reg_read+0x39/0x60
[674104.938834]  vfs_read+0x91/0x150
[674104.939536]  ksys_read+0x4f/0xb0
[674104.940213]  do_syscall_64+0x5b/0x1a0
[674104.940971]  entry_SYSCALL_64_after_hwframe+0x66/0xcb
[674104.941926] RIP: 0033:0x7fa2d3988722

lctl get_param was trying to access osd*.MDT.stats while umount was in progress. i.e. lctl was accessing just released stats structure.

Issue Links

• is related to: LU-18950 Add nodemap level stats aggregation in Lustre