block: Add Error parameter to bdrv_find_protocol()

The argument given to bdrv_find_protocol() is just a file name, which
makes it difficult for the caller to reconstruct what protocol
bdrv_find_protocol() was hoping to find. This patch adds an Error
parameter to that function to solve this issue.

Suggested-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1423162705-32065-4-git-send-email-mreitz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
Max Reitz 2015-02-05 13:58:12 -05:00 committed by Stefan Hajnoczi
parent ca49a4fdb3
commit b65a5e12a4
5 changed files with 19 additions and 15 deletions

View file

@ -1730,7 +1730,7 @@ static int sd_create(const char *filename, QemuOpts *opts,
BlockDriver *drv;
/* Currently, only Sheepdog backing image is supported. */
drv = bdrv_find_protocol(backing_file, true);
drv = bdrv_find_protocol(backing_file, true, NULL);
if (!drv || strcmp(drv->protocol_name, "sheepdog") != 0) {
error_setg(errp, "backing_file must be a sheepdog image");
ret = -EINVAL;