Re: [PATCH 5.15 00/57] 5.15.155-rc1 review

[Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>]

Hi Greg, Chuck,

On 12/04/24 21:27, Chuck Lever III wrote:
> 
> 
>> I have noticed a regression in lts test case with nfsv4 and this was overlooked in the previous cycle(5.15.154). So the regression is from 153-->154 update. And I think that is due to nfs backports we had in 5.15.154.
>>
>> # ./runltp -d /tmpdir -s fcntl17
>>
>> <<<test_start>>>
>> tag=fcntl17 stime=1712915065
...
>> fcntl17     1  TFAIL  :  fcntl17.c:429: Alarm expired, deadlock not detected
>> fcntl17     0  TWARN  :  fcntl17.c:430: You may need to kill child processes by hand
>> fcntl17     2  TPASS  :  Block 1 PASSED
>> fcntl17     0  TINFO  :  Exit block 1
>> fcntl17     0  TWARN  :  tst_tmpdir.c:342: tst_rmdir: rmobj(/tmpdir/ltp-jRFBtBQhhx/LTP_fcn9Xy4hM) failed: unlink(/tmpdir/ltp-jRFBtBQhhx/LTP_fcn9Xy4hM) failed; errno=2: ENOENT
>>
>>
>> Steps used after installing latest ltp:
>>
>> $ mkdir /tmpdir
>> $ yum install nfs-utils  -y
>> $ echo "/media *(rw,no_root_squash,sync)" >/etc/exports
>> $ systemctl start nfs-server.service
>> $ mount -o rw,nfsvers=3 127.0.0.1:/media /tmpdir
>> $ cd /opt/ltp
>> $ ./runltp -d /tmpdir -s fcntl17
>>
>>
>>
>> This does not happen in 5.15.153 tag.
>>
>> Adding nfs people to the CC list
> 
> The reproducer uses NFSv3, but the bug report says NFSv4
> at the top.
> 
> I was able to reproduce this on my nfsd-5.15.y branch
> with NFSv3.
> 
> A bisect would be most helpful.
> 

I was able to bisect: here are the results:



2267b2e84593bd3d61a1188e68fba06307fa9dab is the first bad commit
commit 2267b2e84593bd3d61a1188e68fba06307fa9dab
Author: Alexander Aring <aahringo@redhat.com>
Date:   Tue Sep 12 17:53:18 2023 -0400

     lockd: introduce safe async lock op

     [ Upstream commit 2dd10de8e6bcbacf85ad758b904543c294820c63 ]

     This patch reverts mostly commit 40595cdc93ed ("nfs: block notification
     on fs with its own ->lock") and introduces an EXPORT_OP_ASYNC_LOCK
     export flag to signal that the "own ->lock" implementation supports
     async lock requests. The only main user is DLM that is used by GFS2 and
     OCFS2 filesystem. Those implement their own lock() implementation and
     return FILE_LOCK_DEFERRED as return value. Since commit 40595cdc93ed
     ("nfs: block notification on fs with its own ->lock") the DLM
     implementation were never updated. This patch should prepare for DLM
     to set the EXPORT_OP_ASYNC_LOCK export flag and update the DLM
     plock implementation regarding to it.

     Acked-by: Jeff Layton <jlayton@kernel.org>
     Signed-off-by: Alexander Aring <aahringo@redhat.com>
     Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

  Documentation/filesystems/nfs/exporting.rst |  7 +++++++
  fs/lockd/svclock.c                          |  4 +---
  fs/nfsd/nfs4state.c                         | 10 +++++++---
  include/linux/exportfs.h                    | 14 ++++++++++++++
  4 files changed, 29 insertions(+), 6 deletions(-)

Bisect log:
==========

git bisect start
# status: waiting for both good and bad commits
# bad: [cdfd0a7f01396303e9d4fb3513a1127636f12e5e] Linux 5.15.154
git bisect bad cdfd0a7f01396303e9d4fb3513a1127636f12e5e
# status: waiting for good commit(s), bad commit known
# good: [9465fef4ae351749f7068da8c78af4ca27e61928] Linux 5.15.153
git bisect good 9465fef4ae351749f7068da8c78af4ca27e61928
# good: [4420d19ed4e4fe2adc9bed8a49bf195db1137458] NFSD: Report average 
age of filecache items
git bisect good 4420d19ed4e4fe2adc9bed8a49bf195db1137458
# good: [94e412c945e64579798204aee7bc669d0acfaf79] nfsd: fix courtesy 
client with deny mode handling in nfs4_upgrade_open
git bisect good 94e412c945e64579798204aee7bc669d0acfaf79
# bad: [254f1c2521716cafc63530750ce313059f5d5979] iwlwifi: mvm: rfi: use 
kmemdup() to replace kzalloc + memcpy
git bisect bad 254f1c2521716cafc63530750ce313059f5d5979
# bad: [e635f652696ef6f1230621cfd89c350cb5ec6169] serial: sc16is7xx: 
convert from _raw_ to _noinc_ regmap functions for FIFO
git bisect bad e635f652696ef6f1230621cfd89c350cb5ec6169
# good: [05b452e8748bcf92c00725691437e16d46af7c28] nfsd: Fix creation 
time serialization order
git bisect good 05b452e8748bcf92c00725691437e16d46af7c28
# bad: [ccd9fe71b9ee46ebcecec8aec5c4f1e1ddd35dfd] nfsd: Fix a regression 
in nfsd_setattr()
git bisect bad ccd9fe71b9ee46ebcecec8aec5c4f1e1ddd35dfd
# bad: [2267b2e84593bd3d61a1188e68fba06307fa9dab] lockd: introduce safe 
async lock op
git bisect bad 2267b2e84593bd3d61a1188e68fba06307fa9dab
# good: [56e5eeff6cfa4bd6ffa2b2ae5b8bfc1c28044faf] nfsd: separate 
nfsd_last_thread() from nfsd_put()
git bisect good 56e5eeff6cfa4bd6ffa2b2ae5b8bfc1c28044faf
# good: [6e5fed48d8b7b25f8517a1292b62a3a86a5aec91] NFSD: fix possible 
oops when nfsd/pool_stats is closed.
git bisect good 6e5fed48d8b7b25f8517a1292b62a3a86a5aec91
# first bad commit: [2267b2e84593bd3d61a1188e68fba06307fa9dab] lockd: 
introduce safe async lock op


Hope the above might help.

I didnot test the revert of culprit commit on top of 5.15.154 yet.

Thanks,
Harshit