btrfs: test decompression in the middle of large extents

This is a regression test for "Btrfs: fix btrfs_decompress_buf2page()".
It fails for zlib on v4.10-rc[1-7].

Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Eryu Guan <eguan@redhat.com>
Signed-off-by: Eryu Guan <eguan@redhat.com>

diff --git a/common/btrfs b/common/btrfs
index 96c3635bcc5113c00c2a586da95e2d04ae289c69..b342644cf1e655f7fdd9dd515a746c055c0ed1bc 100644 (file)
--- a/common/btrfs
+++ b/common/btrfs
@@ -364,3 +364,11 @@ _reload_btrfs_ko()
        modprobe -r btrfs || _fail "btrfs unload failed"
        modprobe btrfs || _fail "btrfs load failed"
 }
+
+_btrfs_compression_algos()
+{
+       echo zlib
+       for feature in /sys/fs/btrfs/features/compress_*; do
+               echo "${feature#/sys/fs/btrfs/features/compress_}"
+       done
+}

diff --git a/tests/btrfs/138 b/tests/btrfs/138
new file mode 100755 (executable)
index 0000000..a456a84
--- /dev/null
+++ b/tests/btrfs/138
@@ -0,0 +1,97 @@
+#! /bin/bash
+# FS QA Test 138
+#
+# Test decompression in the middle of large extents. Regression test for Linux
+# kernel commit 6e78b3f7a193 ("Btrfs: fix btrfs_decompress_buf2page()").
+#
+#-----------------------------------------------------------------------
+# Copyright (c) 2017 Facebook.  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"
+
+here=`pwd`
+tmp=/tmp/$$
+status=1       # failure is the default!
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+_cleanup()
+{
+       cd /
+       rm -f $tmp.*
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+
+# remove previous $seqres.full before test
+rm -f $seqres.full
+
+# real QA test starts here
+
+_supported_fs btrfs
+_supported_os Linux
+_require_scratch
+_require_btrfs_command property
+
+algos=($(_btrfs_compression_algos))
+
+_scratch_mkfs >>$seqres.full 2>&1
+_scratch_mount
+# Need 1GB for the uncompressed file plus <1GB for each compressed file.
+_require_fs_space $SCRATCH_MNT $((1024 * 1024 * (1 + ${#algos[@]})))
+
+# Checksum a piece in the middle of the file. This hits the unaligned case that
+# caused the original bug.
+do_csum()
+{
+       dd if="$1" bs=4K skip=555 count=100 2>>$seqres.full| md5sum | cut -d ' ' -f 1
+}
+
+# Create a large, uncompressed (but compressible) file.
+touch "${SCRATCH_MNT}/uncompressed"
+$BTRFS_UTIL_PROG property set "${SCRATCH_MNT}/uncompressed" compression ""
+_ddt of="${SCRATCH_MNT}/uncompressed" bs=1M count=1K 2>&1 | _filter_dd
+
+csum="$(do_csum "${SCRATCH_MNT}/uncompressed")"
+
+for algo in ${algos[@]}; do
+       echo "Testing ${algo}" >> $seqres.full
+
+       # Copy the same data, but with compression enabled.
+       touch "${SCRATCH_MNT}/${algo}"
+       $BTRFS_UTIL_PROG property set "${SCRATCH_MNT}/${algo}" compression "${algo}"
+       dd if="${SCRATCH_MNT}/uncompressed" of="${SCRATCH_MNT}/${algo}" bs=1M 2>&1 | _filter_dd
+
+       # The correct data is likely still cached. Cycle the mount to drop the
+       # cache and start fresh.
+       _scratch_cycle_mount
+
+       # Check the checksum.
+       compressed_csum="$(do_csum "${SCRATCH_MNT}/${algo}")"
+       if [ "${compressed_csum}" != "${csum}" ]; then
+               echo "Checksum mismatch for ${algo} (expected ${csum}, got ${compressed_csum})"
+       fi
+done
+
+echo "Silence is golden"
+
+status=0
+exit

diff --git a/tests/btrfs/138.out b/tests/btrfs/138.out
new file mode 100644 (file)
index 0000000..614ba1a
--- /dev/null
+++ b/tests/btrfs/138.out
@@ -0,0 +1,2 @@
+QA output created by 138
+Silence is golden

diff --git a/tests/btrfs/group b/tests/btrfs/group
index 009dea10913b3579b6b94b1ce19641577d29f9ee..76a1181ed1b8cee6b5607f3797da427135c852b0 100644 (file)
--- a/tests/btrfs/group
+++ b/tests/btrfs/group
@@ -140,3 +140,4 @@
 135 auto quick send
 136 auto convert
 137 auto quick send
+138 auto compress