block: create bdrv_get_backing_file_depth()
Create bdrv_get_backing_file_depth() in order to be able to show
in QMP and HMP how many ancestors backing an image a block device
have.
Signed-off-by: Benoit Canet <benoit@irqsave.net>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
diff --git a/block.c b/block.c
index b38940b..1206bba 100644
--- a/block.c
+++ b/block.c
@@ -2754,6 +2754,19 @@
return NULL;
}
+int bdrv_get_backing_file_depth(BlockDriverState *bs)
+{
+ if (!bs->drv) {
+ return 0;
+ }
+
+ if (!bs->backing_hd) {
+ return 0;
+ }
+
+ return 1 + bdrv_get_backing_file_depth(bs->backing_hd);
+}
+
#define NB_SUFFIXES 4
char *get_human_readable_size(char *buf, int buf_size, int64_t size)
diff --git a/block.h b/block.h
index c89590d..650d872 100644
--- a/block.h
+++ b/block.h
@@ -174,6 +174,7 @@
int nb_sectors, int *pnum);
BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
const char *backing_file);
+int bdrv_get_backing_file_depth(BlockDriverState *bs);
int bdrv_truncate(BlockDriverState *bs, int64_t offset);
int64_t bdrv_getlength(BlockDriverState *bs);
int64_t bdrv_get_allocated_file_size(BlockDriverState *bs);