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//')" + +_scratch_mkfs >> $seqres.full 2>&1 || _fail "mkfs failed" +_scratch_mount + +blksz=$(_get_block_size "$SCRATCH_MNT") + +# 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
