kernel null pointer at nvme_tcp_init_iter+0x7d/0xd0 [nvme_tcp]

[Chaitanya Kulkarni]

On 2/10/21 2:06 PM, Sagi Grimberg wrote:
>>> [   75.235059] nvme_tcp: rq 38 opcode 8
>>> [   75.238653] blk_update_request: I/O error, dev nvme0c0n1, sector
>>> 1048624 op 0x9:(WRITE_ZEROES) flags 0x2800800 phys_seg 0 prio class 0
>>> [   75.380179] XFS (nvme0n1): Mounting V5 Filesystem
>>> [   75.387457] XFS (nvme0n1): Ending clean mount
>>> [   75.388555] xfs filesystem being mounted at /mnt/blktests supports
>>> timestamps until 2038 (0x7fffffff)
>>> [   91.035659] XFS (nvme0n1): Unmounting Filesystem
>>> [   91.043334] nvme nvme0: Removing ctrl: NQN "blktests-subsystem-1"
>> But write-zeores is also data less command and should not fail.
> And it has a bio, which means that nvme-tcp tries to init an iter
> for it when it shouldn't. So the actual offending commit is:
> cb9b870fba3e, which cleaned up how the iter is initialized but 
> introduced this issue.
>
Looking at cb9b870fba3e, that should work, but really surprised that it
never
got triggered even once in my testing since the issue is reported.