New warning in nvme_setup_discard

[Laurence Oberman]

On Thu, 2021-07-15 at 16:19 +0200, Greg Kroah-Hartman wrote:
> On Thu, Jul 15, 2021 at 03:56:38PM +0200, Oleksandr Natalenko wrote:
> > Hello.
> > 
> > After a v5.13.2 massive update I encountered this:
> > 
> > ```
> > [19231.556665] ------------[ cut here ]------------
> > [19231.556674] WARNING: CPU: 20 PID: 502 at
> > drivers/nvme/host/core.c:850 
> > nvme_setup_discard+0x188/0x1f0
> > ...
> > [19231.556776] CPU: 20 PID: 502 Comm: kworker/20:1H Not tainted
> > 5.13.2 #1
> > [19231.556780] Hardware name: ASUS System Product Name/Pro WS X570-
> > ACE, BIOS 
> > 3601 05/26/2021
> > [19231.556784] Workqueue: kblockd blk_mq_run_work_fn
> > [19231.556789] RIP: 0010:nvme_setup_discard+0x188/0x1f0
> > [19231.556794] Code: 49 8b 44 24 10 4c 8b 90 40 0b 00 00 4c 2b 15
> > 8f 09 d8 00 
> > 49 c1 fa 06 49 c1 e2 0c 4c 03 15 90 09 d8 00 4d 89 d0 e9 b9 fe ff
> > ff <0f> 0b b8 
> > 00 00 00 80 49 01 c2 72 52 48 c7 c0 00 00 00 80 48 2b 05
> > [19231.556798] RSP: 0018:ffffaed2416efc00 EFLAGS: 00010287
> > [19231.556802] RAX: ffff8e67fb580000 RBX: ffff8e640bbe5240 RCX:
> > 0000000000000020
> > [19231.556805] RDX: ffff8e67fb580000 RSI: 000000000000001f RDI:
> > 0000000000000000
> > [19231.556808] RBP: ffff8e640bbe5388 R08: ffff8e677b580000 R09:
> > 0000000008abb800
> > [19231.556811] R10: ffff8e677b580000 R11: 0000000000000400 R12:
> > ffff8e6405999c00
> > [19231.556814] R13: 000000000000001f R14: ffff8e6405693000 R15:
> > ffff8e640bbaf800
> > [19231.556816] FS:  0000000000000000(0000)
> > GS:ffff8e6b0ef00000(0000) knlGS:
> > 0000000000000000
> > [19231.556819] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > [19231.556822] CR2: ffff888c76ece000 CR3: 000000047a184000 CR4:
> > 0000000000350ee0
> > [19231.556825] Call Trace:
> > [19231.556830]  nvme_setup_cmd+0x2d0/0x670
> > [19231.556834]  nvme_queue_rq+0x79/0xc90
> > [19231.556837]  ? __sbitmap_get_word+0x30/0x80
> > [19231.556842]  ? sbitmap_get+0x85/0x180
> > [19231.556846]  blk_mq_dispatch_rq_list+0x15c/0x810
> > [19231.556851]  ? list_sort+0x21d/0x2f0
> > [19231.556856]  __blk_mq_do_dispatch_sched+0x196/0x320
> > [19231.556860]  __blk_mq_sched_dispatch_requests+0x14d/0x190
> > [19231.556864]  blk_mq_sched_dispatch_requests+0x2f/0x60
> > [19231.556867]  blk_mq_run_work_fn+0x43/0xc0
> > [19231.556871]  process_one_work+0x24e/0x430
> > [19231.556876]  worker_thread+0x54/0x4d0
> > [19231.556880]  ? process_one_work+0x430/0x430
> > [19231.556883]  kthread+0x1b3/0x1e0
> > [19231.556886]  ? __kthread_init_worker+0x50/0x50
> > [19231.556889]  ret_from_fork+0x22/0x30
> > [19231.556895] ---[ end trace d9abdf019a56b4c7 ]---
> > [19231.556906] blk_update_request: I/O error, dev nvme1n1, sector
> > 632935424 op 
> > 0x3:(DISCARD) flags 0x0 phys_seg 31 prio class 0
> > ```
> > 
> > or, in code:
> > 
> > ```
> >  850     if (WARN_ON_ONCE(n != segments)) {
> >  851         if (virt_to_page(range) == ns->ctrl->discard_page)
> >  852             clear_bit_unlock(0, &ns->ctrl->discard_page_busy);
> >  853         else
> >  854             kfree(range);
> >  855         return BLK_STS_IOERR;
> >  856     }
> > ```
> > 
> > BFQ scheduler is in use.
> > 
> > Something similar was already fixed by
> > a958937ff166fc60d1c3a721036f6ff41bfa2821, 
> > but I do not have a multipath device here, it's just 2 NVMe SSDs in
> > a soft 
> > RAID10 with LUKS and LVM.
> > 
> > Any idea what this might mean? v5.13.2 brought some commit into a
> > stable tree 
> > that are, as I still suspect, causing unreproducible panics [1]
> > [2]. 
> > Previously, I dropped that extra stuff from my kernel build and had
> > no issues. 
> > This time I also do not have any extra commits in the block layer,
> > only those 
> > that are in v5.13.2.
> > 
> > Thanks.
> > 
> > [1] https://lore.kernel.org/linux-block/3533087.dJKXTdksHR@spock/
> > [2] https://lore.kernel.org/linux-block/2957867.CS06ZTPI5V@spock/
> 
> Can you run 'git bisect' to find the offending patch?
> 
> thanks,
> 
> greg k-h
> 


Hello


[root at ml150 ~]# uname -a
Linux ml150 5.14.0-rc1+ #1 SMP Thu Jul 15 16:41:08 EDT 2021 x86_64
x86_64 x86_64 GNU/Linux

[root at ml150 ~]# nvme list
Node             SN                   Model                            
        Namespace Usage                      Format           FW Rev  
---------------- -------------------- -------------------------------
--------- --------- -------------------------- ---------------- -----
---
/dev/nvme0n1     CVCQ536300C9400AGN   INTEL
SSDPEDMW400G4                      1         400.09  GB /
400.09  GB    512   B +  0 B   8EV10135
/dev/nvme1n1     CVFT7383000W400BGN   INTEL
SSDPEDMD400G4                      1         400.09  GB /
400.09  GB    512   B +  0 B   8DV10171

fwiw

I built 5.14 and I have 2 nvme devices and I am not seeing this even
using them to build the kernel on.

Regards
Laurence Oberman