kernel null pointer at nvme_tcp_init_iter[nvme_tcp] with blktests nvme-tcp/012

[Chaitanya Kulkarni]

Yi,

On 2/6/21 20:51, Yi Zhang wrote:
> The issue was introduced after merge the NVMe updates
>
> commit 0fd6456fd1f4c8f3ec5a2df6ed7f34458a180409 (HEAD)
> Merge: 44d10e4b2f2c 0d7389718c32
> Author: Jens Axboe <axboe at kernel.dk>
> Date:   Tue Feb 2 07:12:06 2021 -0700
>
>      Merge branch 'for-5.12/drivers' into for-next
>
>      * for-5.12/drivers: (22 commits)
>        nvme-tcp: use cancel tagset helper for tear down
>        nvme-rdma: use cancel tagset helper for tear down
>        nvme-tcp: add clean action for failed reconnection
>        nvme-rdma: add clean action for failed reconnection
>        nvme-core: add cancel tagset helpers
>        nvme-core: get rid of the extra space
>        nvme: add tracing of zns commands
>        nvme: parse format nvm command details when tracing
>        nvme: update enumerations for status codes
>        nvmet: add lba to sect conversion helpers
>        nvmet: remove extra variable in identify ns
>        nvmet: remove extra variable in id-desclist
>        nvmet: remove extra variable in smart log nsid
>        nvme: refactor ns->ctrl by request
>        nvme-tcp: pass multipage bvec to request iov_iter
>        nvme-tcp: get rid of unused helper function
>        nvme-tcp: fix wrong setting of request iov_iter
>        nvme: support command retry delay for admin command
>        nvme: constify static attribute_group structs
>        nvmet-fc: use RCU proctection for assoc_list
>
>
> On 2/6/21 11:08 AM, Yi Zhang wrote:
>> blktests nvme-tcp/012
Thanks for reporting, you can further bisect this using following
NVMe tree if is from NVMEe tree :- http://git.infradead.org/nvme.git
Branch :- 5.12

Looking at the commit log it seems like nvme-tcp commits might be
the issue given that you got the problem in nvme_tcp_init_iter()
and just eliminating by the looking at the code
commit 9f99a29e5307 can lead to this behavior.

*I may be completely wrong as I'm not expert in the nvme-tcp host.*