qemu-iotests: Overlapping cluster allocations

A new test on corrupted images with overlapping cluster allocations.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

tests/qemu-iotests/060

+#!/bin/bash
+#
+# Test case for image corruption (overlapping data structures) in qcow2
+#
+# Copyright (C) 2013 Red Hat, Inc.
+#
+# 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; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will 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, see <http://www.gnu.org/licenses/>.
+#
+
+# creator
+owner=mreitz@redhat.com
+
+seq=`basename $0`
+echo "QA output created by $seq"
+
+here=`pwd`
+tmp=/tmp/$$
+status=1	# failure is the default!
+
+_cleanup()
+{
+	_cleanup_test_img
+}
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+# get standard environment, filters and checks
+. ./common.rc
+. ./common.filter
+
+# This tests qocw2-specific low-level functionality
+_supported_fmt qcow2
+_supported_proto generic
+_supported_os Linux
+
+rt_offset=65536  # 0x10000 (XXX: just an assumption)
+rb_offset=131072 # 0x20000 (XXX: just an assumption)
+l1_offset=196608 # 0x30000 (XXX: just an assumption)
+l2_offset=262144 # 0x40000 (XXX: just an assumption)
+
+IMGOPTS="compat=1.1"
+
+echo
+echo "=== Testing L2 reference into L1 ==="
+echo
+_make_test_img 64M
+# Link first L1 entry (first L2 table) onto itself
+# (Note the MSb in the L1 entry is set, ensuring the refcount is one - else any
+# later write will result in a COW operation, effectively ruining this attempt
+# on image corruption)
+poke_file "$TEST_IMG" "$l1_offset" "\x80\x00\x00\x00\x00\x03\x00\x00"
+_check_test_img
+
+# The corrupt bit should not be set anyway
+./qcow2.py "$TEST_IMG" dump-header | grep incompatible_features
+
+# Try to write something, thereby forcing the corrupt bit to be set
+$QEMU_IO -c "write -P 0x2a 0 512" "$TEST_IMG" | _filter_qemu_io
+
+# The corrupt bit must now be set
+./qcow2.py "$TEST_IMG" dump-header | grep incompatible_features
+
+# Try to open the image R/W (which should fail)
+$QEMU_IO -c "read 0 512" "$TEST_IMG" 2>&1 | _filter_qemu_io | sed -e "s/can't open device .*$/can't open device/"
+
+# Try to open it RO (which should succeed)
+$QEMU_IO -c "read 0 512" -r "$TEST_IMG" | _filter_qemu_io
+
+# We could now try to fix the image, but this would probably fail (how should an
+# L2 table linked onto the L1 table be fixed?)
+
+echo
+echo "=== Testing cluster data reference into refcount block ==="
+echo
+_make_test_img 64M
+# Allocate L2 table
+truncate -s "$(($l2_offset+65536))" "$TEST_IMG"
+poke_file "$TEST_IMG" "$l1_offset" "\x80\x00\x00\x00\x00\x04\x00\x00"
+# Mark cluster as used
+poke_file "$TEST_IMG" "$(($rb_offset+8))" "\x00\x01"
+# Redirect new data cluster onto refcount block
+poke_file "$TEST_IMG" "$l2_offset" "\x80\x00\x00\x00\x00\x02\x00\x00"
+_check_test_img
+./qcow2.py "$TEST_IMG" dump-header | grep incompatible_features
+$QEMU_IO -c "write -P 0x2a 0 512" "$TEST_IMG" | _filter_qemu_io
+./qcow2.py "$TEST_IMG" dump-header | grep incompatible_features
+
+# Try to fix it
+_check_test_img -r all
+
+# The corrupt bit should be cleared
+./qcow2.py "$TEST_IMG" dump-header | grep incompatible_features
+
+# Look if it's really really fixed
+$QEMU_IO -c "write -P 0x2a 0 512" "$TEST_IMG" | _filter_qemu_io
+./qcow2.py "$TEST_IMG" dump-header | grep incompatible_features
+
+# success, all done
+echo "*** done"
+rm -f $seq.full
+status=0

tests/qemu-iotests/060.out

+QA output created by 060
+
+=== Testing L2 reference into L1 ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 
+ERROR cluster 3 refcount=1 reference=3
+
+1 errors were found on the image.
+Data may be corrupted, or further writes to the image may corrupt it.
+incompatible_features     0x0
+qcow2: Preventing invalid write on metadata (overlaps with active L1 table); image marked as corrupt.
+write failed: Input/output error
+incompatible_features     0x2
+qcow2: Image is corrupt; cannot be opened read/write.
+qemu-io: can't open device
+no file open, try 'help open'
+read 512/512 bytes at offset 0
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+=== Testing cluster data reference into refcount block ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 
+ERROR refcount block 0 refcount=2
+ERROR cluster 2 refcount=1 reference=2
+
+2 errors were found on the image.
+Data may be corrupted, or further writes to the image may corrupt it.
+incompatible_features     0x0
+qcow2: Preventing invalid write on metadata (overlaps with refcount block); image marked as corrupt.
+write failed: Input/output error
+incompatible_features     0x2
+Repairing refcount block 0 refcount=2
+The following inconsistencies were found and repaired:
+
+    0 leaked clusters
+    1 corruptions
+
+Double checking the fixed image now...
+No errors were found on the image.
+incompatible_features     0x0
+wrote 512/512 bytes at offset 0
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+incompatible_features     0x0
+*** done

tests/qemu-iotests/group

@@ -64,4 +64,5 @@
 055 rw auto
 056 rw auto backing
 059 rw auto
+060 rw auto
 062 rw auto