Re: 'ls /mnt/scratch/' freeze(deadlock?) when run xfstest(btrfs/232)

[Wang Yugui <wangyugui@e16-tech.com>]

Hi,

> >>> we run xfstest on two server with this patch.
> >>> one passed the tests.
> >>> but one got a btrfs/232 error.
> >>>
> >>> btrfs/232 32s ... _check_btrfs_filesystem: filesystem on
> >>> /dev/nvme0n1p1is inconsistent
> >>> (see /usr/hpc-bio/xfstests/results//btrfs/232.full for details)
> >>> ...
> >>> [4/7] checking fs roots
> >>> root 5 inode 337 errors 400, nbytes wrong
> >>> ERROR: errors found in fs roots
> >>
> >> Ok, that's a different problem caused by something else.
> >> It's possible to be due to the recent refactorings for preparation to
> >> subpage block size.
> >
> > This error looks exactly what I have seen during subpage development.
> > The subpage bug is caused by incorrect btrfs_invalidatepage() though,
> > and not yet merged into misc-next anyway.
> >
> > I guess it's some error path not clearing extent states correctly, thus
> > leaving the inode nbytes accounting wrong.
> >
> > BTW, the new @in_reclaim_context parameter for start_delalloc_inodes()
> > is already in misc-next:
> > commit 3d45f221ce627d13e2e6ef3274f06750c84a6542
> > Author: Filipe Manana <fdmanana@suse.com>
> > Date:?? Wed Dec 2 11:55:58 2020 +0000
> >
> >  ?? btrfs: fix deadlock when cloning inline extent and low on free
> > metadata space
> >
> > We only need to make btrfs_start_delalloc_snapshot() to accept the new
> > parameter and pass in_reclaim_context = true for qgroup.
> 
> Strangely, on my subpage branch, with new @in_reclaim_context parameter
> added to btrfs_start_delalloc_snapshot(), I can't reproduce the nbytes
> mismatch error in 32 runs loop.
> I guess one of the refactor around ordered extents and invalidatepage
> may fix the problem by accident.
> 
> Mind to test my subpage branch
> (https://github.com/adam900710/linux/tree/subpage) with the attached diff?

The attached diff( more in_reclaim_context) seems a replacement for 
https://pastebin.com/raw/U9GUZiEf (less in_reclaim_context).

so I  will firstly test with the attached diff but drop
https://pastebin.com/raw/U9GUZiEf.

The test of whole subpage branch will be done later.

Best Regards
Wang Yugui (wangyugui@e16-tech.com)
2021/04/22