block: Prepare for NULL BDS

blk_bs() will not necessarily return a non-NULL value any more (unless
blk_is_available() is true or it can be assumed to otherwise, e.g.
because it is called immediately after a successful blk_new_with_bs() or
blk_new_open()).

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Max Reitz 2015-10-19 17:53:29 +02:00 committed by Kevin Wolf
parent 0c3c36d651
commit 5433c24f0f
6 changed files with 154 additions and 72 deletions

View file

@ -931,9 +931,11 @@ static int blk_connect(struct XenDevice *xendev)
blk_attach_dev_nofail(blkdev->blk, blkdev);
blkdev->file_size = blk_getlength(blkdev->blk);
if (blkdev->file_size < 0) {
BlockDriverState *bs = blk_bs(blkdev->blk);
const char *drv_name = bs ? bdrv_get_format_name(bs) : NULL;
xen_be_printf(&blkdev->xendev, 1, "blk_getlength: %d (%s) | drv %s\n",
(int)blkdev->file_size, strerror(-blkdev->file_size),
bdrv_get_format_name(blk_bs(blkdev->blk)) ?: "-");
drv_name ?: "-");
blkdev->file_size = 0;
}