Re: [bug report][regression] blktests nvme/029 failed on latest linux-block/for-next

[Nilay Shroff <nilay@linux.ibm.com>]

On 11/21/24 08:28, Yi Zhang wrote:
> On Wed, Nov 20, 2024 at 10:07 PM Nilay Shroff <nilay@linux.ibm.com> wrote:
>>
>>
>>
>> On 11/19/24 16:34, Yi Zhang wrote:
>>> Hello
>>>
>>> CKI recently reported the blktests nvme/029 failed[1] on the
>>> linux-block/for-next, and bisect shows it was introduced from [2],
>>> please help check it and let me know if you need any info/test for it, thanks.
>>>
>>> [1]
>>> nvme/029 (tr=loop) (test userspace IO via nvme-cli read/write
>>> interface) [failed]
>>>     runtime    ...  1.568s
>>>     --- tests/nvme/029.out 2024-11-19 08:13:41.379272231 +0000
>>>     +++ /root/blktests/results/nodev_tr_loop/nvme/029.out.bad
>>> 2024-11-19 10:55:13.615939542 +0000
>>>     @@ -1,2 +1,8 @@
>>>      Running nvme/029
>>>     +FAIL
>>>     +FAIL
>>>     +FAIL
>>>     +FAIL
>>>     +FAIL
>>>     +FAIL
>>>     ...
>>>     (Run 'diff -u tests/nvme/029.out
>>> /root/blktests/results/nodev_tr_loop/nvme/029.out.bad' to see the
>>> entire diff)
>>> [2]
>>> 64a51080eaba (HEAD) nvmet: implement id ns for nvm command set
>>>
>>>
>>> --
>>> Best Regards,
>>>   Yi Zhang
>>>
>>>
>> I couldn't reproduce it even after running nvme/029 in a loop
>> for multiple times. Are you following any specific steps to
>> recreate it?
> 
> From the reproduced data[1], seems it only reproduced on x86_64 and
> aarch64, and from the 029.full[2], we can see the failure comes from
> the "nvme write" cmd.
> [1]
> https://datawarehouse.cki-project.org/issue/3263
> [2]
> # cat results/nodev_tr_loop/nvme/029.full
> Reference tag larger than allowed by PIF
> NQN:blktests-subsystem-1 disconnected 1 controller(s)
> disconnected 1 controller(s)
> 
> I also attached the kernel config file in case you want to try it, thanks.
> 
Thanks for the additional information!
Now I could understand the issue and have a probable fix. If possible, can you try 
the below patch and check if it help resolve this issue?

diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c
index 934b401fbc2f..7a8256ae3085 100644
--- a/drivers/nvme/target/admin-cmd.c
+++ b/drivers/nvme/target/admin-cmd.c
@@ -901,12 +901,14 @@ static void nvmet_execute_identify_ctrl_nvm(struct nvmet_req *req)
 static void nvme_execute_identify_ns_nvm(struct nvmet_req *req)
 {
        u16 status;
+       void *zero_buf;
 
        status = nvmet_req_find_ns(req);
        if (status)
                goto out;
 
-       status = nvmet_copy_to_sgl(req, 0, ZERO_PAGE(0),
+       zero_buf = __va(page_to_pfn(ZERO_PAGE(0)) << PAGE_SHIFT);
+       status = nvmet_copy_to_sgl(req, 0, zero_buf,
                                   NVME_IDENTIFY_DATA_SIZE);
 out:
        nvmet_req_complete(req, status);

Thanks,
--Nilay