block/dmg: set virtual size to a non-zero value

Right now the virtual size is always reported as zero which makes it
impossible to convert between formats.

After this patch, the number of sectors will be read from the trailer
("koly" block).

To verify the behavior, the output of `dmg2img foo.dmg foo.img` was
compared against `qemu-img convert -f dmg -O raw foo.dmg foo.raw`. The
tests showed that the file contents are exactly the same, except that
QEMU creates a slightly larger file (it matches the total sectors
count).

Signed-off-by: Peter Wu <peter@lekensteyn.nl>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 1420566495-13284-8-git-send-email-peter@lekensteyn.nl
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Peter Wu 2015-01-06 18:48:10 +01:00 committed by Kevin Wolf
parent 0599e56ed4
commit 8daf425794

View File

@ -452,6 +452,14 @@ static int dmg_open(BlockDriverState *bs, QDict *options, int flags,
ret = -EINVAL;
goto fail;
}
ret = read_uint64(bs, offset + 0x1ec, (uint64_t *)&bs->total_sectors);
if (ret < 0) {
goto fail;
}
if (bs->total_sectors < 0) {
ret = -EINVAL;
goto fail;
}
if (rsrc_fork_length != 0) {
ret = dmg_read_resource_fork(bs, &ds,
rsrc_fork_offset, rsrc_fork_length);