[LU-14531] racer with DoM enabled crashes in ZFS

Tue, 19 Oct 2021 15:45:50 +0000
BUG: unable to handle kernel NULL pointer dereference at 0000000000000028
PGD 0 P4D 0 
Oops: 0000 [#1] SMP DEBUG_PAGEALLOC
CPU: 1 PID: 9163 Comm: dp_sync_taskq Tainted: P        W  O     --------- ---  4.18.0 #35
Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
RIP: 0010:dbuf_sync_leaf+0x3f3/0x790 [zfs]
Code: 00 00 00 4c 89 e7 e8 5c a9 fe ff 48 8b 95 38 02 00 00 48 c7 85 30 02 00 00 00 00 00 00 48 39 d3 75 08 e9 f1 02 00 00 48 89 c2 <48> 8b 42 28 48 39 c3 75 f4 48 83 c2 28 48 8b 43 28 48 89 02 48 8b
RSP: 0018:ffff8801937cbba8 EFLAGS: 00010286
RAX: 0000000000000001 RBX: ffff8800c4a34e00 RCX: ffffffffffffff80
RDX: 0000000000000000 RSI: ffff8800c95bcfc0 RDI: ffff8800c95bce00
RBP: ffff8800d5b12d70 R08: 5a5a5a5a5a5a5a5a R09: 5a5a5a5a5a5a5a5a
R10: 5a5a5a5a5a5a5a5a R11: 5a5a5a5a5a5a5a5a R12: ffff8800d5b12dc8
R13: ffff8800c3cae950 R14: ffff880193070000 R15: ffff8800c4a34e00
FS:  0000000000000000(0000) GS:ffff8801a9e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000028 CR3: 00000000d4aeb000 CR4: 00000000000006a0
Call Trace:
 dbuf_sync_list+0xf0/0x100 [zfs]
 dnode_sync+0x5f0/0xf80 [zfs]
 ? __mutex_unlock_slowpath+0x38/0x280
 sync_dnodes_task+0x42/0x170 [zfs]
 taskq_thread+0x2c4/0x4a0 [spl]
 ? wake_up_q+0x60/0x60
 kthread+0x100/0x140
 ? taskq_thread_should_stop+0x70/0x70 [spl]
 ? kthread_flush_work_fn+0x10/0x10
Whamcloud Community JIRA

[LU-14531] racer with DoM enabled crashes in ZFS
