vpc: use current_size field for XenServer VHD images

The vpc driver has two methods of determining virtual disk size.  The
correct one to use depends on the software that generated the image
file.  Add the XenServer creator_app signature so that image size is
correctly detected for those images.

Reported-by: Grant Wu <grantwwu@gmail.com>
Reported-by: Spencer Baugh <sbaugh@catern.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

diff --git a/block/vpc.c b/block/vpc.c
index 5aded1a18b3e1cbc0051e90b7411dc36a359a5a1..228f2c96e132c26e3531a2d5f0e667a8382490a1 100644 (file)
--- a/block/vpc.c
+++ b/block/vpc.c
@@ -299,6 +299,7 @@ static int vpc_open(BlockDriverState *bs, QDict *options, int flags,
      *      'qem2'  :  current_size     QEMU (uses current_size)
      *      'win '  :  current_size     Hyper-V
      *      'd2v '  :  current_size     Disk2vhd
+     *      'tap\0' :  current_size     XenServer
      *
      *  The user can override the table values via drive options, however
      *  even with an override we will still use current_size for images
@@ -306,7 +307,8 @@ static int vpc_open(BlockDriverState *bs, QDict *options, int flags,
      */
     use_chs = (!!strncmp(footer->creator_app, "win ", 4) &&
                !!strncmp(footer->creator_app, "qem2", 4) &&
-               !!strncmp(footer->creator_app, "d2v ", 4)) || s->force_use_chs;
+               !!strncmp(footer->creator_app, "d2v ", 4) &&
+               !!memcmp(footer->creator_app, "tap", 4)) || s->force_use_chs;
 
     if (!use_chs || bs->total_sectors == VHD_MAX_GEOMETRY || s->force_use_sz) {
         bs->total_sectors = be64_to_cpu(footer->current_size) /