Re: [PATCH 6.1 CANDIDATE 0/3] xfs inodegc fixes for 6.1.y (from v6.4)

["Darrick J. Wong" <djwong@kernel.org>]

On Wed, Jul 12, 2023 at 12:47:30PM +0300, Amir Goldstein wrote:
> Darrick,
> 
> These are the patches we discussed that Leah requested for the 5.15.y
> backport of non-blocking inodegc pushes series [1].
> 
> They may or may not help the 5.15.y -> 6.1.y regression that was
> reported by Chris [2].
> 
> Note that I did not include:
> 2d5f38a31980 ("xfs: disable reaping in fscounters scrub")
> in this backport set, because I generally do not want to deal with
> backporting fixes for experimental features.

I don't agree with this decision because the comment for
xfs_inodegc_stop now says that callers must hold s_umount.
xchk_stop_reaping definitely does /not/ hold that lock, which means it's
now buggy.  Someone downstream could be using scrub, even if it's still
experimental.

I've generally said not to bother with scrub fixes, but I don't think
it's correct to introduce a bug in an LTS kernel.  Please backport
2d5f38a31980 since all it does is removes the offending call and turns
off code in fscounters.c.

--D

> This series has gone through the usual kdevops testing routine.
> 
> Please ACK.
> 
> Thanks,
> Amir.
> 
> [1] https://www.spinics.net/lists/linux-xfs/msg61813.html
> [2] https://lore.kernel.org/all/ZK4E%2FgGuaBu+qvKL@dread.disaster.area/
> 
> Darrick J. Wong (3):
>   xfs: explicitly specify cpu when forcing inodegc delayed work to run
>     immediately
>   xfs: check that per-cpu inodegc workers actually run on that cpu
>   xfs: fix xfs_inodegc_stop racing with mod_delayed_work
> 
>  fs/xfs/xfs_icache.c | 40 +++++++++++++++++++++++++++++++++-------
>  fs/xfs/xfs_mount.h  |  3 +++
>  fs/xfs/xfs_super.c  |  3 +++
>  3 files changed, 39 insertions(+), 7 deletions(-)
> 
> -- 
> 2.34.1
>