common/nvme: remove allowed_hosts before remove subsys in nvmet configfs

[yizhanglinux]

$ nvme_trtype=tcp ./check nvme/063
nvme/063 (tr=tcp) (Create authenticated TCP connections with secure concatenation)
runtime 2.220s ...
WARNING: Test did not clean up port: 0
nvme/063 (tr=tcp) (Create authenticated TCP connections with secure concatenation) [failed]
runtime 2.220s ... 2.217sost: nqn.2014-08.org.nvmexpress:uuid:0f01fb42-9f7f-4856-b0b3-51e60b8de349
--- tests/nvme/063.out 2025-11-02 02:47:38.826227836 -0500
+++ /root/blktests/results/nodev_tr_tcp/nvme/063.out.bad 2025-11-02 08:43:09.743150576 -0500
@@ -1,7 +1,3 @@
Running nvme/063
Test secure concatenation with SHA256
-Reset controller
-disconnected 1 controller(s)
-Test secure concatenation with SHA384
-disconnected 1 controller(s)
-Test complete
...
(Run 'diff -u tests/nvme/063.out /root/blktests/results/nodev_tr_tcp/nvme/063.out.bad' to see the entire diff)

Link: #207

[kawasaki]

@yizhanglinux I guess the failure of nvme/063 indicates a bug in kernel side, and it should be fixed with this patch. Could you try it out?

[yizhanglinux]

@yizhanglinux I guess the failure of nvme/063 indicates a bug in kernel side, and it should be fixed with this patch. Could you try it out?

Yes, just confirmed the failure issue was fixed by the patch.

[igaw]

I think adding the cleanup code would still make sense, as it makes the test suite more robust, no?

[kawasaki]

I think adding the cleanup code would still make sense, as it makes the test suite more robust, no?

I'm not so sure for this case. If we apply the cleanup code, it would hide the failure we found, and the bug was overlooked.

[yizhanglinux]

It will not hide the failure, and the test still can fail.
The patch just cleans up the following configfs after the test failed, or it will impact the following test case.

# nvmetcli ls
o- / .......................................................................................................... [...]
  o- hosts .................................................................................................... [...]
  | o- nqn.2014-08.org.nvmexpress:uuid:0f01fb42-9f7f-4856-b0b3-51e60b8de349 ................................... [...]
  o- ports .................................................................................................... [...]
  o- subsystems ............................................................................................... [...]
    o- blktests-subsystem-1 ................................. [version=2.1, allow_any=0, serial=f3e8fd2c6a5d1ad81d8e]
      o- allowed_hosts ........................................................................................ [...]
      | o- nqn.2014-08.org.nvmexpress:uuid:0f01fb42-9f7f-4856-b0b3-51e60b8de349 ............................... [...]
      o- namespaces ........................................................................................... [...]

[kawasaki]

@yizhanglinux Thanks for the clarification. Now I agree to apply this change, and it has done :)