From 9f4793d8f2f1abf20dc1d7d55f65ce8df081ca7a Mon Sep 17 00:00:00 2001 From: Max Reitz Date: Fri, 1 Feb 2019 20:29:16 +0100 Subject: [PATCH] block: Add bdrv_make_absolute_filename() This is a general function for making a filename that is relative to a certain BDS absolute. It calls bdrv_get_full_backing_filename_from_filename() for now, but that will be changed in a follow-up patch. Signed-off-by: Max Reitz Reviewed-by: Alberto Garcia Message-id: 20190201192935.18394-13-mreitz@redhat.com Signed-off-by: Max Reitz --- block.c | 27 ++++++++++++++++++++------- 1 file changed, 20 insertions(+), 7 deletions(-) diff --git a/block.c b/block.c index a2203f0cfe..c66cd111e1 100644 --- a/block.c +++ b/block.c @@ -338,16 +338,29 @@ char *bdrv_get_full_backing_filename_from_filename(const char *backed, } } -char *bdrv_get_full_backing_filename(BlockDriverState *bs, Error **errp) +/* + * If @filename is empty or NULL, this function returns NULL without + * setting @errp. In all other cases, NULL will only be returned with + * @errp set. + */ +static char *bdrv_make_absolute_filename(BlockDriverState *relative_to, + const char *filename, Error **errp) { - char *backed; + char *bs_filename; - bdrv_refresh_filename(bs); + bdrv_refresh_filename(relative_to); + + bs_filename = relative_to->exact_filename[0] + ? relative_to->exact_filename + : relative_to->filename; - backed = bs->exact_filename[0] ? bs->exact_filename : bs->filename; - return bdrv_get_full_backing_filename_from_filename(backed, - bs->backing_file, - errp); + return bdrv_get_full_backing_filename_from_filename(bs_filename, + filename ?: "", errp); +} + +char *bdrv_get_full_backing_filename(BlockDriverState *bs, Error **errp) +{ + return bdrv_make_absolute_filename(bs, bs->backing_file, errp); } void bdrv_register(BlockDriver *bdrv) -- 2.11.4.GIT