+#! /bin/bash
+# FS QA Test No. btrfs/037
+#
+# Test for a btrfs data corruption when using compressed files/extents.
+# Under certain cases, it was possible for reads to return random data
+# (content from a previously used page) instead of zeroes. This also
+# caused partial updates to those regions that were supposed to be filled
+# with zeroes to save random (and invalid) data into the file extents.
+#
+# This is fixed by the commit for the linux kernel titled:
+#
+# Btrfs: fix data corruption when reading/updating compressed extents
+#
+#-----------------------------------------------------------------------
+# Copyright (c) 2014 Filipe Manana. All Rights Reserved.
+#
+# 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=`mktemp -d`
+
+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
+_supported_fs btrfs
+_supported_os Linux
+_require_scratch
+_need_to_be_root
+
+rm -f $seqres.full
+
+_scratch_mkfs >/dev/null 2>&1
+_scratch_mount "-o compress-force=lzo"
+
+$XFS_IO_PROG -f -c "pwrite -S 0x06 -b 18670 266978 18670" \
+ $SCRATCH_MNT/foobar | _filter_xfs_io
+$XFS_IO_PROG -c "falloc 26450 665194" $SCRATCH_MNT/foobar | _filter_xfs_io
+$XFS_IO_PROG -c "truncate 542872" $SCRATCH_MNT/foobar | _filter_xfs_io
+$XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foobar | _filter_xfs_io
+
+# Expected file items in the fs tree are (from btrfs-debug-tree):
+#
+# item 4 key (257 INODE_ITEM 0) itemoff 15879 itemsize 160
+# inode generation 6 transid 6 size 542872 block group 0 mode 100600
+# item 5 key (257 INODE_REF 256) itemoff 15863 itemsize 16
+# inode ref index 2 namelen 6 name: foobar
+# item 6 key (257 EXTENT_DATA 0) itemoff 15810 itemsize 53
+# extent data disk byte 0 nr 0 gen 6
+# extent data offset 0 nr 24576 ram 266240
+# extent compression 0
+# item 7 key (257 EXTENT_DATA 24576) itemoff 15757 itemsize 53
+# prealloc data disk byte 12849152 nr 241664 gen 6
+# prealloc data offset 0 nr 241664
+# item 8 key (257 EXTENT_DATA 266240) itemoff 15704 itemsize 53
+# extent data disk byte 12845056 nr 4096 gen 6
+# extent data offset 0 nr 20480 ram 20480
+# extent compression 2
+# item 9 key (257 EXTENT_DATA 286720) itemoff 15651 itemsize 53
+# prealloc data disk byte 13090816 nr 405504 gen 6
+# prealloc data offset 0 nr 258048
+#
+# The on disk extent at 266240, contains 5 compressed chunks of file data.
+# Each of the first 4 chunks compress 4096 bytes of file data, while the last
+# one compresses only 3024 bytes of file data. Because this extent item is not
+# the last one in the file, as it followed by a prealloc extent, reads into
+# the region [285648 ; 286720[ (length = 4096 - 3024) should return zeroes.
+
+_scratch_unmount
+_check_btrfs_filesystem $SCRATCH_DEV
+
+EXPECTED_MD5="b8b0dbb8e02f94123c741c23659a1c0a"
+
+for i in `seq 1 27`
+do
+ _scratch_mount "-o ro"
+ MD5=`md5sum $SCRATCH_MNT/foobar | cut -f 1 -d ' '`
+ _scratch_unmount
+ if [ "${MD5}x" != "${EXPECTED_MD5}x" ]
+ then
+ echo "Unexpected file digest (wanted $EXPECTED_MD5, got $MD5)"
+ fi
+done
+
+status=0
+exit
projects / xfstests-dev.git / commitdiff