diff options
Diffstat (limited to 'block/io.c')
| -rw-r--r-- | block/io.c | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/block/io.c b/block/io.c index 9ba1bada36..24a18759fd 100644 --- a/block/io.c +++ b/block/io.c @@ -2295,10 +2295,11 @@ int coroutine_fn bdrv_is_allocated(BlockDriverState *bs, int64_t offset, /* * Given an image chain: ... -> [BASE] -> [INTER1] -> [INTER2] -> [TOP] * - * Return true if (a prefix of) the given range is allocated in any image - * between BASE and TOP (inclusive). BASE can be NULL to check if the given - * offset is allocated in any image of the chain. Return false otherwise, - * or negative errno on failure. + * Return 1 if (a prefix of) the given range is allocated in any image + * between BASE and TOP (BASE is only included if include_base is set). + * BASE can be NULL to check if the given offset is allocated in any + * image of the chain. Return 0 otherwise, or negative errno on + * failure. * * 'pnum' is set to the number of bytes (including and immediately * following the specified offset) that are known to be in the same @@ -2310,17 +2311,21 @@ int coroutine_fn bdrv_is_allocated(BlockDriverState *bs, int64_t offset, */ int bdrv_is_allocated_above(BlockDriverState *top, BlockDriverState *base, - int64_t offset, int64_t bytes, int64_t *pnum) + bool include_base, int64_t offset, + int64_t bytes, int64_t *pnum) { BlockDriverState *intermediate; int ret; int64_t n = bytes; + assert(base || !include_base); + intermediate = top; - while (intermediate && intermediate != base) { + while (include_base || intermediate != base) { int64_t pnum_inter; int64_t size_inter; + assert(intermediate); ret = bdrv_is_allocated(intermediate, offset, bytes, &pnum_inter); if (ret < 0) { return ret; @@ -2339,6 +2344,10 @@ int bdrv_is_allocated_above(BlockDriverState *top, n = pnum_inter; } + if (intermediate == base) { + break; + } + intermediate = backing_bs(intermediate); } |