block: Get full backing filename from string
Introduce bdrv_get_full_backing_filename_from_filename(), a function
which takes the name of the backed file and a potentially relative
backing filename to produce the full (absolute) backing filename.
Use this function from bdrv_get_full_backing_filename().
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/block.c b/block.c
index 58f8042..86f2faa 100644
--- a/block.c
+++ b/block.c
@@ -303,13 +303,21 @@
}
}
+void bdrv_get_full_backing_filename_from_filename(const char *backed,
+ const char *backing,
+ char *dest, size_t sz)
+{
+ if (backing[0] == '\0' || path_has_protocol(backing)) {
+ pstrcpy(dest, sz, backing);
+ } else {
+ path_combine(dest, sz, backed, backing);
+ }
+}
+
void bdrv_get_full_backing_filename(BlockDriverState *bs, char *dest, size_t sz)
{
- if (bs->backing_file[0] == '\0' || path_has_protocol(bs->backing_file)) {
- pstrcpy(dest, sz, bs->backing_file);
- } else {
- path_combine(dest, sz, bs->filename, bs->backing_file);
- }
+ bdrv_get_full_backing_filename_from_filename(bs->filename, bs->backing_file,
+ dest, sz);
}
void bdrv_register(BlockDriver *bdrv)
