diff mbox

[PULL,26/42] block/dmg: set virtual size to a non-zero value

Message ID 1423240849-15499-27-git-send-email-kwolf@redhat.com
State New
Headers show

Commit Message

Kevin Wolf Feb. 6, 2015, 4:40 p.m. UTC 
From: Peter Wu <peter@lekensteyn.nl>

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>
---
 block/dmg.c | 8 ++++++++
 1 file changed, 8 insertions(+)
diff mbox

Patch

diff --git a/block/dmg.c b/block/dmg.c
index a78506a..a33c131 100644
--- a/block/dmg.c
+++ b/block/dmg.c
@@ -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);