Re: [PATCH v2] blk: avoid divide-by-zero with zero granularity

[Feng Li]

Hi Martin,

I use the nvme-tcp as the host, the target is spdk nvme-tcp target,
and set a wrong block size(i.g. bs=8), then the host prints this oops:

[   63.153018] nvme nvme0: creating 3 I/O queues.
[   63.181644] nvme nvme0: mapped 3/0/0 default/read/poll queues.
[   63.185568] nvme nvme0: new ctrl: NQN
"nqn.2018-11.io.spdk:nvmf-test", addr 192.168.64.217:4421
[   63.189440] divide error: 0000 [#1] SMP NOPTI
[   63.190963] CPU: 0 PID: 122 Comm: kworker/u8:2 Not tainted
5.9.9-200.fc33.x86_64 #1
[   63.193426] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS 1.14.0-1.fc33 04/01/2014
[   63.196263] Workqueue: nvme-wq nvme_scan_work [nvme_core]
[   63.198015] RIP: 0010:blk_stack_limits+0x189/0x440
[   63.199549] Code: 43 28 0f b6 45 62 08 43 62 8b 4d 2c 39 4d 38 0f
43 4d 38 31 d2 45 31 f6 48 8b 04 24 8b 75 34 89 cf 44 8b 43 34 c1 ef
09 09
[   63.203169] RSP: 0018:ffffb312001ffc98 EFLAGS: 00010202
[   63.204034] RAX: 0000000000000000 RBX: ffff9463b270ecc8 RCX: 0000000000000008
[   63.205205] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000000
[   63.206377] RBP: ffff9463b27083f8 R08: 0000000000000000 R09: 0000000000000008
[   63.207553] R10: ffff9463b81d6420 R11: 0000035f00000000 R12: ffff9463b2bea000
[   63.208725] R13: ffff9463b6d31258 R14: 0000000000000000 R15: ffff9463b6c22800
[   63.209914] FS:  0000000000000000(0000) GS:ffff9463bec00000(0000)
knlGS:0000000000000000
[   63.211239] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   63.212186] CR2: 000055d73270e690 CR3: 0000000036b32000 CR4: 00000000000006f0
[   63.213383] Call Trace:
[   63.213826]  ? blk_mq_freeze_queue_wait+0x13/0x80
[   63.214609]  __nvme_revalidate_disk+0x191/0x2d0 [nvme_core]
[   63.215528]  nvme_validate_ns+0x3fa/0x960 [nvme_core]
[   63.216374]  nvme_scan_work+0x165/0x3c0 [nvme_core]
[   63.217183]  process_one_work+0x1b4/0x370
[   63.217852]  worker_thread+0x53/0x3e0
[   63.218458]  ? process_one_work+0x370/0x370
[   63.219156]  kthread+0x11b/0x140
[   63.219700]  ? __kthread_bind_mask+0x60/0x60
[   63.220403]  ret_from_fork+0x22/0x30

Martin K. Petersen <martin.petersen@xxxxxxxxxx> 于2021年1月13日周三 上午1:10写道：
>
>
> Li,
>
> > If the physical_block_size and io_min is less than a sector,
>
> That's not supposed to happen. What device/driver is this?
>
> --
> Martin K. Petersen      Oracle Linux Engineering