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

[Chaitanya Kulkarni]

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
Can you try following patch and see in your Oops if you get that message
so that
we can at-least eliminate one case ?

diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
index 619b0d8f6e38..13d44d155478 100644
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -2271,8 +2271,11 @@ static blk_status_t nvme_tcp_setup_cmd_pdu(struct
nvme_ns *ns,
        req->data_len = blk_rq_nr_phys_segments(rq) ?
                                blk_rq_payload_bytes(rq) : 0;
        req->curr_bio = rq->bio;
-       if (req->curr_bio)
+       if (req->curr_bio) {
+               if (rq->bio != rq->biotail)
+                       printk(KERN_INFO"%s %d req->bio !=
req->biotail\n", __func__, __LINE__);
                nvme_tcp_init_iter(req, rq_data_dir(rq));
+       }
 
        if (rq_data_dir(rq) == WRITE &&
            req->data_len <= nvme_tcp_inline_data_size(queue))