We have a longstanding bug that creating a seed sprout fs with the ro->rw transition done with mount -o remount,rw $mnt instead of umount $mnt mount $sprout_dev $mnt results in an fs without BTRFS_FS_OPEN set, which fails to ever run the critical btrfs cleaner thread. This test reproduces that bug and detects it by creating and deleting a subvolume, then triggering the cleaner thread. The expected behavior is for the cleaner thread to delete the stale subvolume and for the list to show no entries. Without the fix, we see a DELETED entry for the subvol. Reviewed-by: Qu Wenruo <wqu@xxxxxxxx> Signed-off-by: Boris Burkov <boris@xxxxxx> --- Changelog: v3: - add volume group - switch to SCRATCH_DEV/SPARE_DEV - filter scratch devs from mount/findmnt output instead of suppressing. This adds the expected read only message that comes with mounting seed devices to the golden output, and makes the ro/rw check more natural. v2: - update to real copyright info - add extra rw->ro transition checks - remove unnecessary _require_test --- tests/btrfs/323 | 47 +++++++++++++++++++++++++++++++++++++++++++++ tests/btrfs/323.out | 4 ++++ 2 files changed, 51 insertions(+) create mode 100755 tests/btrfs/323 create mode 100644 tests/btrfs/323.out diff --git a/tests/btrfs/323 b/tests/btrfs/323 new file mode 100755 index 000000000..4e389d66a --- /dev/null +++ b/tests/btrfs/323 @@ -0,0 +1,47 @@ +#! /bin/bash +# SPDX-License-Identifier: GPL-2.0 +# Copyright (c) 2024 Meta Platforms, Inc. All Rights Reserved. +# +# FS QA Test 323 +# +# Test that remounted seed/sprout device FS is fully functional. For example, that it can purge stale subvolumes. +# +. ./common/preamble +_begin_fstest auto quick seed remount + +. ./common/filter +_require_command "$BTRFS_TUNE_PROG" btrfstune +_require_scratch_dev_pool 2 + +_fixed_by_kernel_commit XXXXXXXX \ + "btrfs: do not clear read-only when adding sprout device" + +_scratch_dev_pool_get 1 +_spare_dev_get + +# create a read-only fs based off a read-only seed device +_scratch_mkfs >>$seqres.full +$BTRFS_TUNE_PROG -S 1 $SCRATCH_DEV +_scratch_mount 2>&1 | _filter_scratch +_btrfs device add -f $SPARE_DEV $SCRATCH_MNT >>$seqres.full + +# switch ro to rw, checking that it was ro before and rw after +findmnt -n -O ro -o TARGET $SCRATCH_MNT | _filter_scratch +_mount -o remount,rw $SCRATCH_MNT +findmnt -n -O rw -o TARGET $SCRATCH_MNT | _filter_scratch + +# do stuff in the seed/sprout fs +_btrfs subvolume create $SCRATCH_MNT/subv +_btrfs subvolume delete $SCRATCH_MNT/subv + +# trigger cleaner thread without remounting +_btrfs filesystem sync $SCRATCH_MNT + +# expect no deleted subvolumes remaining +$BTRFS_UTIL_PROG subvolume list -d $SCRATCH_MNT + +_spare_dev_put + +# success, all done +status=0 +exit diff --git a/tests/btrfs/323.out b/tests/btrfs/323.out new file mode 100644 index 000000000..1ca2e4b13 --- /dev/null +++ b/tests/btrfs/323.out @@ -0,0 +1,4 @@ +QA output created by 323 +mount: SCRATCH_MNT: WARNING: source write-protected, mounted read-only. +SCRATCH_MNT +SCRATCH_MNT -- 2.46.0
