Test that btrfs' transaction abortion does not corrupt a filesystem
mounted with -o discard nor allows a subsequent fstrim to corrupt the
filesystem (regardless of being mounted with or without -o discard).
This issue was fixed by the following linux kernel patch:
Btrfs: fix fs corruption on transaction abort if device supports discard
(commit 678886bdc6378c1cbd5072da2c5a3035000214e3)
Without the corresponding btrfs fix the fs becomes unmountable and fails
like this:
$ ./check btrfs/089
FSTYP -- btrfs
PLATFORM -- Linux/x86_64 debian3 3.19.0-btrfs-next-7+
MKFS_OPTIONS -- /dev/sdc
MOUNT_OPTIONS -- /dev/sdc /home/fdmanana/btrfs-tests/scratch_1
btrfs/089 2s ... - output mismatch (see /home/fdmanana/git/hub/xfstests/results//btrfs/089.out.bad)
--- tests/btrfs/089.out 2015-04-02 16:46:28.022498841 +0100
+++ /home/fdmanana/git/hub/xfstests/results//btrfs/089.out.bad 2015-04-02 16:48:05.406195409 +0100
@@ -1,2 +1,8 @@
QA output created by 089
-File content after transaction abort + remount: hello
+mount: wrong fs type, bad option, bad superblock on /dev/sdc,
+ missing codepage or helper program, or other error
+ In some cases useful info is found in syslog - try
+ dmesg | tail or so
+
...
(Run 'diff -u tests/btrfs/089.out /home/fdmanana/git/hub/xfstests/results//btrfs/089.out.bad' to see the entire diff)
_check_btrfs_filesystem: filesystem on /dev/sdc is inconsistent (see /home/fdmanana/git/hub/xfstests/results//btrfs/089.full)
Ran: btrfs/089
Failures: btrfs/089
Failed 1 of 1 tests
$ cat /home/fdmanana/git/hub/xfstests/results//btrfs/089.full
Performing full device TRIM (100.00GiB) ...
_check_btrfs_filesystem: filesystem on /dev/sdc is inconsistent
*** fsck.btrfs output ***
Check tree block failed, want=29573120, have=0
Check tree block failed, want=29573120, have=0
Check tree block failed, want=29573120, have=0
Check tree block failed, want=29573120, have=0
Check tree block failed, want=29573120, have=0
read block failed check_tree_block
Couldn't read tree root
Couldn't open file system
(...)
Signed-off-by: Filipe Manana <fdmanana@xxxxxxxx>
---
tests/btrfs/089 | 129 ++++++++++++++++++++++++++++++++++++++++++++++++++++
tests/btrfs/089.out | 2 +
tests/btrfs/group | 1 +
3 files changed, 132 insertions(+)
create mode 100755 tests/btrfs/089
create mode 100644 tests/btrfs/089.out
diff --git a/tests/btrfs/089 b/tests/btrfs/089
new file mode 100755
index 0000000..032a8aa
--- /dev/null
+++ b/tests/btrfs/089
@@ -0,0 +1,129 @@
+#! /bin/bash
+# FS QA Test No. btrfs/089
+#
+# Test that btrfs' transaction abortion does not corrupt a filesystem mounted
+# with -o discard nor allows a subsequent fstrim to corrupt the filesystem
+# (regardless of being mounted with or without -o discard).
+#
+# This issue was fixed by the following linux kernel patch:
+#
+# Btrfs: fix fs corruption on transaction abort if device supports discard
+# (commit 678886bdc6378c1cbd5072da2c5a3035000214e3)
+#
+#-----------------------------------------------------------------------
+# Copyright (C) 2015 SUSE Linux Products GmbH. All Rights Reserved.
+# Author: Filipe Manana <fdmanana@xxxxxxxx>
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it would be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write the Free Software Foundation,
+# Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+#-----------------------------------------------------------------------
+#
+
+seq=`basename $0`
+seqres=$RESULT_DIR/$seq
+echo "QA output created by $seq"
+
+tmp=/tmp/$$
+status=1 # failure is the default!
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+_cleanup()
+{
+ rm -f $tmp.*
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+
+# real QA test starts here
+_supported_fs btrfs
+_supported_os Linux
+_require_scratch
+_require_fail_make_request
+_need_to_be_root
+
+allow_fail_make_request()
+{
+ echo 100 > $DEBUGFS_MNT/fail_make_request/probability
+ echo 9999999 > $DEBUGFS_MNT/fail_make_request/times
+ echo 0 > /sys/kernel/debug/fail_make_request/verbose
+}
+
+disallow_fail_make_request()
+{
+ echo 0 > $DEBUGFS_MNT/fail_make_request/probability
+ echo 0 > $DEBUGFS_MNT/fail_make_request/times
+}
+
+SCRATCH_BDEV=`_short_dev $SCRATCH_DEV`
+
+start_fail_scratch_dev()
+{
+ echo 1 > /sys/block/$SCRATCH_BDEV/make-it-fail
+}
+
+stop_fail_scratch_dev()
+{
+ echo 0 > /sys/block/$SCRATCH_BDEV/make-it-fail
+}
+
+rm -f $seqres.full
+
+# We will abort a btrfs transaction later, which always produces a warning in
+# dmesg. We do not want the test to fail because of this.
+_disable_dmesg_check
+
+_scratch_mkfs >>$seqres.full 2>&1
+_scratch_mount "-o discard"
+_require_batched_discard $SCRATCH_MNT
+
+# Create a file, small enough to be inlined in the metadata, and commit the
+# current transaction.
+echo -n "hello" > $SCRATCH_MNT/foo
+sync
+
+# Now update the file, which forces a COW operation of the fs root, adding
+# the old root location to the pinned extents list.
+echo -n " world" >> $SCRATCH_MNT/foo
+
+# Now make sure the next transaction commit will abort the transaction, unmount
+# the fs, mount it again and verify we can open the file and read its content,
+# which should be what it had when the last superblock was committed (first call
+# to sync), since btrfs is a COW filesystem.
+# Btrfs used to issue a discard operation on the extents in the pinned extents
+# list, resulting in corruption of metadata and data, and used too to return the
+# pinned extents to the free space caches, allowing future fstrim operations to
+# perform a discard operation against the pinned exents. This made the fs
+# unmountable because the btree roots that the superblock points at were written
+# in place (by the discard operations).
+allow_fail_make_request
+start_fail_scratch_dev
+# This sync will trigger a commit of the current transaction, which will be
+# aborted because IO will fail.
+sync
+stop_fail_scratch_dev
+disallow_fail_make_request
+
+# This fstrim operation should not cause discard operations to be performed
+# against extents that were COWed, otherwise the next mount will fail since
+# the btree roots that the superblock points at have their physical areas
+# on disk full of zeroes.
+$FSTRIM_PROG $SCRATCH_MNT
+
+_scratch_unmount
+_scratch_mount
+echo "File content after transaction abort + remount: $(cat $SCRATCH_MNT/foo)"
+
+status=0
+exit
diff --git a/tests/btrfs/089.out b/tests/btrfs/089.out
new file mode 100644
index 0000000..aebbe2b
--- /dev/null
+++ b/tests/btrfs/089.out
@@ -0,0 +1,2 @@
+QA output created by 089
+File content after transaction abort + remount: hello
diff --git a/tests/btrfs/group b/tests/btrfs/group
index 73ef2ea..83c8ec2 100644
--- a/tests/btrfs/group
+++ b/tests/btrfs/group
@@ -91,3 +91,4 @@
086 auto quick clone
087 auto quick send
088 auto quick clone
+089 auto quick metadata
--
2.1.3
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