qcow2: Check L1 table parameters in qcow2_expand_zero_clusters()

This function iterates over all snapshots of a qcow2 file in order to
expand all zero clusters, but it does not validate the snapshots' L1
tables first.

We now have a function to take care of this, so let's use it.

We can also take the opportunity to replace the sector-based
bdrv_read() with bdrv_pread().

Cc: Eric Blake <eblake@redhat.com>
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Alberto Garcia 2018-03-06 18:14:08 +02:00 committed by Kevin Wolf
parent 314e8d3928
commit c9a442e450
3 changed files with 23 additions and 7 deletions

View file

@ -177,6 +177,7 @@ _make_test_img 64M
{ $QEMU_IMG snapshot -c test $TEST_IMG; } 2>&1 | _filter_testdir
poke_file "$TEST_IMG" "$offset_snap1_l1_offset" "\x00\x00\x00\x00\x00\x40\x02\x00"
{ $QEMU_IMG convert -s test $TEST_IMG $TEST_IMG.snap; } 2>&1 | _filter_testdir
{ $QEMU_IMG amend -o compat=0.10 $TEST_IMG; } 2>&1 | _filter_testdir
echo
echo "== Invalid snapshot L1 table size =="
@ -185,6 +186,7 @@ _make_test_img 64M
{ $QEMU_IMG snapshot -c test $TEST_IMG; } 2>&1 | _filter_testdir
poke_file "$TEST_IMG" "$offset_snap1_l1_size" "\x10\x00\x00\x00"
{ $QEMU_IMG convert -s test $TEST_IMG $TEST_IMG.snap; } 2>&1 | _filter_testdir
{ $QEMU_IMG amend -o compat=0.10 $TEST_IMG; } 2>&1 | _filter_testdir
# success, all done
echo "*** done"

View file

@ -64,10 +64,14 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
wrote 512/512 bytes at offset 0
512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
qemu-img: Failed to load snapshot: Snapshot L1 table offset invalid
qemu-img: Snapshot L1 table offset invalid
qemu-img: Error while amending options: Invalid argument
== Invalid snapshot L1 table size ==
Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
wrote 512/512 bytes at offset 0
512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
qemu-img: Failed to load snapshot: Snapshot L1 table too large
qemu-img: Snapshot L1 table too large
qemu-img: Error while amending options: File too large
*** done