block: Introduce BDRV_O_NO_BACKING

If an image references a backing file that doesn't exist, qemu-img info fails
to open this image. Exactly in this case the info would be valuable, though:
the user might want to find out which file is missing.

This patch introduces a BDRV_O_NO_BACKING flag to ignore the backing file when
opening the image. qemu-img info is the first user and provides info now even
if the backing file is invalid.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/qemu-img.c b/qemu-img.c
index 1d97f2e..5ad88bf 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -884,7 +884,7 @@ static int img_info(int argc, char **argv)
     } else {
         drv = NULL;
     }
-    if (bdrv_open2(bs, filename, BRDV_O_FLAGS, drv) < 0) {
+    if (bdrv_open2(bs, filename, BRDV_O_FLAGS | BDRV_O_NO_BACKING, drv) < 0) {
         error("Could not open '%s'", filename);
     }
     bdrv_get_format(bs, fmt_name, sizeof(fmt_name));