On Wed, Nov 17, 2021 at 10:01:05AM -0800, Darrick J. Wong wrote: > On Mon, Oct 25, 2021 at 09:00:53AM -0400, Brian Foster wrote: > > Test that COW writeback that overlaps non-shared delalloc blocks > > does not leave around stale delalloc blocks on I/O failure. This > > triggers assert failures and free space accounting corruption on > > XFS. > > > > Signed-off-by: Brian Foster <bfoster@xxxxxxxxxx> > > --- > > > > v2: > > - Explicitly set COW extent size hint. > > - Move to tests/xfs. > > - Various minor cleanups. > > v1: https://lore.kernel.org/fstests/20211021163959.1887011-1-bfoster@xxxxxxxxxx/ > > > > tests/xfs/999 | 62 +++++++++++++++++++++++++++++++++++++++++++++++ > > tests/xfs/999.out | 2 ++ > > 2 files changed, 64 insertions(+) > > create mode 100755 tests/xfs/999 > > create mode 100644 tests/xfs/999.out > > > > diff --git a/tests/xfs/999 b/tests/xfs/999 > > new file mode 100755 > > index 00000000..f27972bc > > --- /dev/null > > +++ b/tests/xfs/999 > > @@ -0,0 +1,62 @@ > > +#! /bin/bash > > +# SPDX-License-Identifier: GPL-2.0 > > +# Copyright (c) 2021 Red Hat, Inc. All Rights Reserved. > > +# > > +# FS QA Test 999 > > +# > > +# Test that COW writeback that overlaps non-shared delalloc blocks does not > > +# leave around stale delalloc blocks on I/O failure. This triggers assert > > +# failures and free space accounting corruption on XFS. > > +# > > +. ./common/preamble > > +_begin_fstest auto quick clone > > + > > +_cleanup() > > +{ > > + _cleanup_flakey > > + cd / > > + rm -r -f $tmp.* > > +} > > + > > +# Import common functions. > > +. ./common/reflink > > +. ./common/dmflakey > > + > > +# real QA test starts here > > +_supported_fs xfs > > +_require_scratch_reflink > > +_require_cp_reflink > > +_require_xfs_io_command "cowextsize" > > +_require_flakey_with_error_writes > > + > > +_scratch_mkfs >> $seqres.full > > +_init_flakey > > +_mount_flakey > > + > > +blksz=$(_get_file_block_size $SCRATCH_MNT) > > + > > +# Set the COW extent size hint to guarantee COW fork preallocation occurs over a > > +# bordering block offset. > > +$XFS_IO_PROG -c "cowextsize $((blksz * 2))" $SCRATCH_MNT >> $seqres.full > > + > > +# create two files that share a single block > > +$XFS_IO_PROG -fc "pwrite $blksz $blksz" $SCRATCH_MNT/file1 >> $seqres.full > > +_cp_reflink $SCRATCH_MNT/file1 $SCRATCH_MNT/file2 > > + > > +# Perform a buffered write across the shared and non-shared blocks. On XFS, this > > +# creates a COW fork extent that covers the shared block as well as the just > > +# created non-shared delalloc block. Fail the writeback to verify that all > > +# delayed allocation is cleaned up properly. > > +_load_flakey_table $FLAKEY_ERROR_WRITES > > +$XFS_IO_PROG -c "pwrite 0 $((blksz * 2))" \ > > + -c fsync $SCRATCH_MNT/file2 >> $seqres.full > > +_load_flakey_table $FLAKEY_ALLOW_WRITES > > Hmm. So I've been running this test in my djwong-dev tree and hit this > last night: > > --- xfs/999.out > +++ xfs/999.out.bad > @@ -1,2 +1,3 @@ > QA output created by 999 > -fsync: Input/output error > +stat: Input/output error > +cp: failed to access '/opt/file3': Input/output error > > Digging into the kernel log, I see this happen: > > [10240.821719] XFS (dm-0): Mounting V5 Filesystem > [10240.855461] XFS (dm-0): Ending clean mount > [10240.857030] XFS (dm-0): Quotacheck needed: Please wait. > [10240.860095] XFS (dm-0): Quotacheck: Done. > [10240.977055] XFS (dm-0): log I/O error -5 > [10240.977459] XFS (dm-0): Log I/O Error (0x2) detected at xlog_ioend_work+0x5f/0xb0 [xfs] (fs/xfs/xfs_log.c:1377). Shutting down filesystem. > [10240.978682] XFS (dm-0): Please unmount the filesystem and rectify the problem(s) > [10241.044886] XFS (dm-0): Unmounting Filesystem > > I guess the log tried to checkpoint for the brief window where the > flakey table was enabled, and shut down the whole fs? I don't have any > good ideas for how to solve this, though. > > Hm. What if you did something like: > > $XFS_IO_PROG -c 'pwrite...' $SCRATCH_MNT/file2 > _load_flakey_table $FLAKEY_ERROR_WRITES > $XFS_IO_PROG -c 'sync_range -wa' $SCRATCH_MNT/file2 > +_load_flakey_table $FLAKEY_ALLOW_WRITES > I notice that sync_range doesn't combine options like that even though the underlying flags can be combined for the syscall. That aside, I suspect a combination of an fsync on the earlier reflink command and a couple sync_range calls here (to achieve the intended behavior above) is probably the best option to try and avoid this. That seems to preserve the intended behavior of the test and I don't see any spurious failures in a couple hundred or so iterations.. (granted I don't know how reproducible that was in the first place). Brian > to constrain the window in which disk write will fail? Seeing as s_f_r > doesn't actually tell the fs to flush its own metadata or anything. > > (Yikes, did I finally find a use for sync_file_range??) > > --D > > > + > > +# Try a post-fail reflink and then unmount. Both of these are known to produce > > +# errors and/or assert failures on XFS if we trip over a stale delalloc block. > > +_cp_reflink $SCRATCH_MNT/file2 $SCRATCH_MNT/file3 > > +_unmount_flakey > > + > > +# success, all done > > +status=0 > > +exit > > diff --git a/tests/xfs/999.out b/tests/xfs/999.out > > new file mode 100644 > > index 00000000..88b69c4c > > --- /dev/null > > +++ b/tests/xfs/999.out > > @@ -0,0 +1,2 @@ > > +QA output created by 999 > > +fsync: Input/output error > > -- > > 2.31.1 > > >
