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>
This commit is contained in:
Max Reitz 2014-11-26 17:20:25 +01:00 committed by Stefan Hajnoczi
parent a97ceca578
commit 0a82855a1a
2 changed files with 16 additions and 5 deletions

18
block.c
View file

@ -303,13 +303,21 @@ void path_combine(char *dest, int dest_size,
}
}
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)

View file

@ -397,6 +397,9 @@ void bdrv_get_backing_filename(BlockDriverState *bs,
char *filename, int filename_size);
void bdrv_get_full_backing_filename(BlockDriverState *bs,
char *dest, size_t sz);
void bdrv_get_full_backing_filename_from_filename(const char *backed,
const char *backing,
char *dest, size_t sz);
int bdrv_is_snapshot(BlockDriverState *bs);
int path_has_protocol(const char *path);