[LU-17033] Add RCU protect for export nid operation

• Type: Question/Request
• Resolution: Not a Bug
• Priority: Minor
• Severity: 3
• Assignee: Yang Sheng
• Reporter: Yang Sheng

Description

A few of crash relate to exp_nid_hash. Looks it was operated without RCU protect.

[  257.896656] BUG: unable to handle kernel NULL pointer dereference at 00000000000000e2
[  257.897791] IP: [<ffffffffc0cf1eb0>] ldebugfs_rhash_seq_show+0xa0/0x1e0 [obdclass]
[  257.898814] PGD 21c80e0067 PUD 21bab0c067 PMD 0
[  257.899472] Oops: 0000 [#1] SMP
[  257.914018] CPU: 9 PID: 13241 Comm: lctl Kdump: loaded Tainted: G           OE  ------------ T 3.10.0-1160.95.1.el7_lustre.ddn17.x86_64 #1
[  257.915601] Hardware name: DDN SFA400NVX2E, BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
[  257.916811] task: ffffa1678707d280 ti: ffffa168c6f54000 task.ti: ffffa168c6f54000
[  257.917773] RIP: 0010:[<ffffffffc0cf1eb0>]  [<ffffffffc0cf1eb0>] ldebugfs_rhash_seq_show+0xa0/0x1e0 [obdclass]
[  257.919093] RSP: 0018:ffffa168c6f57d78  EFLAGS: 00010246
[  257.944326] Call Trace:
[  257.945836]  [<ffffffff8c084e93>] ? seq_printf+0x53/0x80
[  257.947705]  [<ffffffffc0cf20b0>] lprocfs_hash_seq_show+0x60/0x90 [obdclass]
[  257.949770]  [<ffffffffc15ff862>] mgs_hash_seq_show+0x12/0x20 [mgs]
[  257.951731]  [<ffffffff8c0857f8>] seq_read+0x138/0x460
[  257.953549]  [<ffffffff8c0d7ad0>] proc_reg_read+0x40/0x80
[  257.955357]  [<ffffffff8c05bb2f>] vfs_read+0x9f/0x170
[  257.957088]  [<ffffffff8c05c9a5>] SyS_read+0x55/0xd0
[  257.958780]  [<ffffffff8c5c639a>] system_call_fastpath+0x25/0x2a

.....

[ 8320.870019] BUG: unable to handle kernel NULL pointer dereference at 00000000000001ca
[ 8320.872531] IP: [<ffffffff98db7459>] rht_deferred_worker+0x209/0x430
[ 8320.874773] PGD 0
[ 8320.876458] Oops: 0000 [#1] SMP
[ 8320.904160] CPU: 13 PID: 3272 Comm: kworker/13:1 Kdump: loaded Tainted: G           OE  ------------ T 3.10.0-1160.88.1.el7_lustre.ddn17.x86_64 #1
[ 8320.907100] Hardware name: DDN SFA400NVX2E, BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
[ 8320.909544] Workqueue: events rht_deferred_worker
[ 8320.911387] task: ffff89c6dfdb3180 ti: ffff89e8c3994000 task.ti: ffff89e8c3994000
[ 8320.913572] RIP: 0010:[<ffffffff98db7459>]  [<ffffffff98db7459>] rht_deferred_worker+0x209/0x430
[ 8320.939508] Call Trace:
[ 8320.940810]  [<ffffffff98ac32ef>] process_one_work+0x17f/0x440
[ 8320.942542]  [<ffffffff98ac4436>] worker_thread+0x126/0x3c0
[ 8320.944188]  [<ffffffff98ac4310>] ? manage_workers.isra.26+0x2b0/0x2b0
[ 8320.946001]  [<ffffffff98acb621>] kthread+0xd1/0xe0
[ 8320.947555]  [<ffffffff98acb550>] ? insert_kthread_work+0x40/0x40
[ 8320.949308]  [<ffffffff991c61dd>] ret_from_fork_nospec_begin+0x7/0x21
[ 8320.951057]  [<ffffffff98acb550>] ? insert_kthread_work+0x40/0x40

Issue Links

• is related to: LU-17034 memory corruption caused by bug in qmt_seed_glbe_all