Re: "[PATCH] nfsd: rework refcounting in filecache" caused nfstest/test/nfstest_delegation stuck

[dai.ngo@oracle.com]

This problem is fixed in nfsd-next with this commit:

119437271d94 NFSD: Fix problem of COMMIT and NFS4ERR_DELAY in infinite loop

-Dai

On 4/26/23 8:50 PM, Jie Zhou (Fujitsu) wrote:
> hi,
>
>      Download nfstest program from
> "http://git.linux-nfs.org/?p=mora/nfstest.git;a=summary".
>      And run following test command and stuck at recall12 recall14
> recall20 recall22 recall40 recall42 recall48 recall50.
>      ./nfstest_delegation --nfsversion=4.0 -e /nfsroot --server <server
> ip> --client <client2 ip> --trcdelay 10
>      test OS: RHEL9.2 Nightly Build
>
>      After I bisect linux kerenl, found that following patch caused above
> bug.
>   From ac3a2585f018f10039b4a856dcb122da88c1c1c9 Mon Sep 17 00:00:00 2001
> From: Jeff Layton <jlayton@kernel.org>
> Date: Sun, 11 Dec 2022 06:19:33 -0500
> Subject: [PATCH] nfsd: rework refcounting in filecache
>
>      Run following command at different kernel version.
> ./nfstest_delegation --nfsversion=4.0 -e /nfsroot --server
> 192.168.122.153 --client 192.168.122.152 --trcdelay 10 -v all
> --createlog --keeptraces --rexeclog recall22
>   >nfstest-delegationv4-log_recall22 2>&1
>
>      The following test result are attached.
>      kernel:
> commit 0cfd8703e7da687924371e9bc77a025bdeba9637
> Merge: 793582ff47f8 d3f2c402e448
> Author: Linus Torvalds <torvalds@linux-foundation.org>
> Date:   Tue Apr 25 18:44:10 2023 -0700
>       Merge tag 'pm-6.4-rc1' of
> git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
>      result:
> test program stuck
>      log:
> nfstest-delegationv4-log_recall22_6.3.0
>
>      kernel:
> commit ac3a2585f018f10039b4a856dcb122da88c1c1c9
> Author: Jeff Layton <jlayton@kernel.org>
> Date:   Sun Dec 11 06:19:33 2022 -0500
>       nfsd: rework refcounting in filecache
>      result:
> test program stuck
>      log:
> nfstest-delegationv4-log_recall22_ac3a2585f018
>
>      kernel:
> commit e78e274eb22d966258a3845acc71d3c5b8ee2ea8
> Author: Kees Cook <keescook@chromium.org>
> Date:   Fri Dec 2 12:48:59 2022 -0800
>       NFSD: Avoid clashing function prototypes
>      result:
> test program stop normally
>      log:
> nfstest-delegationv4-log_recall22_e78e274eb22d
>
> best regards,