From 79fac5680d3680c9fb43d14a8d4e39ced25530f8 Mon Sep 17 00:00:00 2001 From: Jeff Cody Date: Thu, 27 Sep 2012 13:29:15 -0400 Subject: [PATCH] block: helper function, to find the base image of a chain This is a simple helper function, that will return the base image of a given image chain. Signed-off-by: Jeff Cody Reviewed-by: Eric Blake Signed-off-by: Kevin Wolf --- block.c | 16 ++++++++++++++++ block.h | 1 + 2 files changed, 17 insertions(+) diff --git a/block.c b/block.c index 54209a526e..d7a6d14a98 100644 --- a/block.c +++ b/block.c @@ -3117,6 +3117,22 @@ int bdrv_get_backing_file_depth(BlockDriverState *bs) return 1 + bdrv_get_backing_file_depth(bs->backing_hd); } +BlockDriverState *bdrv_find_base(BlockDriverState *bs) +{ + BlockDriverState *curr_bs = NULL; + + if (!bs) { + return NULL; + } + + curr_bs = bs; + + while (curr_bs->backing_hd) { + curr_bs = curr_bs->backing_hd; + } + return curr_bs; +} + #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 8c9b4245d4..e9249c44e6 100644 --- a/block.h +++ b/block.h @@ -207,6 +207,7 @@ int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top, BlockDriverState *base); BlockDriverState *bdrv_find_overlay(BlockDriverState *active, BlockDriverState *bs); +BlockDriverState *bdrv_find_base(BlockDriverState *bs); typedef struct BdrvCheckResult { -- 2.11.4.GIT