--- /dev/null
+#! /bin/bash
+# FSQA Test No. 038
+#
+# This test was motivated by btrfs issues, but it's generic enough as it
+# doesn't use any btrfs specific features.
+#
+# Stress btrfs' block group allocation and deallocation while running fstrim in
+# parallel. Part of the goal is also to get data block groups deallocated so
+# that new metadata block groups, using the same physical device space ranges,
+# get allocated while fstrim is running. This caused several issues ranging
+# from invalid memory accesses, kernel crashes, metadata or data corruption,
+# free space cache inconsistencies, free space leaks and memory leaks.
+#
+# These issues were fixed by the following btrfs linux kernel patches:
+#
+# Btrfs: fix invalid block group rbtree access after bg is removed
+# Btrfs: fix crash caused by block group removal
+# Btrfs: fix freeing used extents after removing empty block group
+# Btrfs: fix race between fs trimming and block group remove/allocation
+# Btrfs: fix race between writing free space cache and trimming
+# Btrfs: make btrfs_abort_transaction consider existence of new block groups
+# Btrfs: fix memory leak after block remove + trimming
+# Btrfs: fix fs mapping extent map leak
+# Btrfs: fix unprotected deletion from pending_chunks list
+#
+# The issues were found on a qemu/kvm guest with 4 virtual CPUs, 4Gb of ram and
+# scsi-hd devices with discard support enabled (that means hole punching in the
+# disk's image file is performed by the host).
+#
+#-----------------------------------------------------------------------
+#
+# Copyright (C) 2014 SUSE Linux Products GmbH. All Rights Reserved.
+# Author: Filipe Manana <fdmanana@suse.com>
+#
+# 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 -fr $tmp
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+
+# real QA test starts here
+_need_to_be_root
+_supported_fs generic
+_supported_os Linux
+_require_scratch
+_require_fstrim
+
+rm -f $seqres.full
+
+# Keep allocating and deallocating 1G of data space with the goal of creating
+# and deleting 1 block group constantly. The intention is to race with the
+# fstrim loop below.
+fallocate_loop()
+{
+ local name=$1
+ while true; do
+ $XFS_IO_PROG -f -c "falloc -k 0 1G" \
+ $SCRATCH_MNT/$name &> /dev/null
+ sleep 3
+ $XFS_IO_PROG -c "truncate 0" \
+ $SCRATCH_MNT/$name &> /dev/null
+ sleep 3
+ done
+}
+
+trim_loop()
+{
+ while true; do
+ $FSTRIM_PROG $SCRATCH_MNT
+ done
+}
+
+# Create a bunch of small files that get their single extent inlined in the
+# btree, so that we consume a lot of metadata space and get a chance of a
+# data block group getting deleted and reused for metadata later. Sometimes
+# the creation of all these files succeeds other times we get ENOSPC failures
+# at some point - this depends on how fast the btrfs' cleaner kthread is
+# notified about empty block groups, how fast it deletes them and how fast
+# the fallocate calls happen. So we don't really care if they all succeed or
+# not, the goal is just to keep metadata space usage growing while data block
+# groups are deleted.
+create_files()
+{
+ local prefix=$1
+
+ for ((i = 1; i <= 400000; i++)); do
+ $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 3900" \
+ $SCRATCH_MNT/"${prefix}_$i" &> /dev/null
+ if [ $? -ne 0 ]; then
+ echo "Failed creating file ${prefix}_$i" >>$seqres.full
+ break
+ fi
+ done
+
+}
+
+_scratch_mkfs >>$seqres.full 2>&1
+_require_fs_space $SCRATCH_MNT $((10 * 1024 * 1024))
+_scratch_mount
+
+for ((i = 0; i < $((4 * $LOAD_FACTOR)); i++)); do
+ trim_loop &
+ trim_pids[$i]=$!
+done
+
+for ((i = 0; i < $((1 * $LOAD_FACTOR)); i++)); do
+ fallocate_loop "falloc_file_$i" &
+ fallocate_pids[$i]=$!
+done
+
+create_files "foobar"
+
+kill ${fallocate_pids[@]}
+kill ${trim_pids[@]}
+wait
+
+# Sleep a bit, otherwise umount fails often with EBUSY (TODO: investigate why).
+sleep 3
+
+# The fstests framework will now check for fs consistency with fsck.
+# The trimming was racy and caused some btree nodes to get full of zeroes on
+# disk, which obviously caused fs metadata corruption. The race often lead
+# to missing free space entries in a block group's free space cache too.
+
+echo "Silence is golden"
+status=0
+exit
projects / xfstests-dev.git / commitdiff