On Tue, May 28, 2024 at 10:13:14AM -0700, Omar Sandoval wrote: > From: Omar Sandoval <osandov@xxxxxx> > > This is a regression test for a Btrfs bug, but there's nothing > Btrfs-specific about it. Since it's a race, we just try to make the race > happen in a loop and pass if it doesn't crash after all of our attempts. > > Signed-off-by: Omar Sandoval <osandov@xxxxxx> > --- > Changes from v2 [1]: > > - Rebased on for-next. > - Added _require_odirect. > - Added FSTYP check to _fixed_by_kernel_commit. > - Added Filipe's Reviewed-by. > > Changes from v1 [2]: > > - Added missing groups and requires. > - Simplified $XFS_IO_PROG calls. > - Removed -i flag from $XFS_IO_PROG to make race reproduce more > reliably. > - Removed all of the file creation and dump-tree parsing since the only > file on a fresh filesystem is guaranteed to be at the end of a leaf > anyways. > - Rewrote to be a generic test. > > 1: https://lore.kernel.org/linux-btrfs/d032e0b964f163229b684c0ac72b656ec9bf7b48.1716584019.git.osandov@xxxxxxxxxxx/ > 2: https://lore.kernel.org/linux-btrfs/297da2b53ce9b697d82d89afd322b2cc0d0f392d.1716492850.git.osandov@xxxxxxxxxxx/ > > tests/generic/748 | 45 +++++++++++++++++++++++++++++++++++++++++++ > tests/generic/748.out | 2 ++ > 2 files changed, 47 insertions(+) > create mode 100755 tests/generic/748 > create mode 100644 tests/generic/748.out > > diff --git a/tests/generic/748 b/tests/generic/748 > new file mode 100755 > index 00000000..2ec33694 > --- /dev/null > +++ b/tests/generic/748 > @@ -0,0 +1,45 @@ > +#! /bin/bash > +# SPDX-License-Identifier: GPL-2.0 > +# Copyright (c) Meta Platforms, Inc. and affiliates. > +# > +# FS QA Test 748 > +# > +# Repeatedly prealloc beyond i_size, set an xattr, direct write into the > +# prealloc while extending i_size, then fdatasync. This is a regression test > +# for a Btrfs crash. > +# > +. ./common/preamble > +. ./common/attr > +_begin_fstest auto quick log preallocrw dangerous > + > +_supported_fs generic > +_require_scratch > +_require_attrs > +_require_odirect > +_require_xfs_io_command falloc -k > +[ "$FSTYP" = btrfs ] && _fixed_by_kernel_commit XXXXXXXXXXXX \ > + "btrfs: fix crash on racing fsync and size-extending write into prealloc" > + > +# -i slows down xfs_io startup and makes the race much less reliable. > +export XFS_IO_PROG="$(echo "$XFS_IO_PROG" | sed 's/ -i\b//')" I think the "export" is not necessary, although it doesn't affect much :) I'll remove it when I merge it. Is that good to you too? > + > +_scratch_mkfs >> $seqres.full 2>&1 || _fail "mkfs failed" > +_scratch_mount > + > +blksz=$(_get_block_size "$SCRATCH_MNT") Maybe you'd like to use _get_file_block_size, which is more accurate to get the minimum block size of a file as a generic test case. I can help to do this change if you agree that too. Thanks, Zorro > + > +# On Btrfs, since this is the only file on the filesystem, its metadata is at > +# the end of a B-tree leaf. We want an ordered extent completion to add an > +# extent item at the end of the leaf while we're logging prealloc extents > +# beyond i_size after an xattr was set. > +for ((i = 0; i < 5000; i++)); do > + $XFS_IO_PROG -ftd -c "falloc -k 0 $((blksz * 3))" -c "pwrite -q -w 0 $blksz" "$SCRATCH_MNT/file" > + $SETFATTR_PROG -n user.a -v a "$SCRATCH_MNT/file" > + $XFS_IO_PROG -d -c "pwrite -q -w $blksz $blksz" "$SCRATCH_MNT/file" > +done > + > +# If it didn't crash, we're good. > + > +echo "Silence is golden" > +status=0 > +exit > diff --git a/tests/generic/748.out b/tests/generic/748.out > new file mode 100644 > index 00000000..dc050a96 > --- /dev/null > +++ b/tests/generic/748.out > @@ -0,0 +1,2 @@ > +QA output created by 748 > +Silence is golden > -- > 2.45.1 > >
