This patch is used in the 'block/stream: introduce a bottom node' that is following. Instead of the base node, the caller may pass the node that has the base as its backing image to the function bdrv_is_allocated_above() with a new parameter include_base = true and get rid of the dependency on the base that may change during commit/stream parallel jobs. Now, if the specified base is not found in the backing image chain, the QEMU will crash.
Suggested-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com> Signed-off-by: Andrey Shinkevich <andrey.shinkev...@virtuozzo.com> --- block/commit.c | 2 +- block/io.c | 14 +++++++++++--- block/mirror.c | 2 +- block/replication.c | 2 +- block/stream.c | 2 +- include/block/block.h | 3 ++- 6 files changed, 17 insertions(+), 8 deletions(-) diff --git a/block/commit.c b/block/commit.c index ba60fef..1bd5284 100644 --- a/block/commit.c +++ b/block/commit.c @@ -177,7 +177,7 @@ static int coroutine_fn commit_run(Job *job, Error **errp) break; } /* Copy if allocated above the base */ - ret = bdrv_is_allocated_above(blk_bs(s->top), blk_bs(s->base), + ret = bdrv_is_allocated_above(blk_bs(s->top), blk_bs(s->base), false, offset, COMMIT_BUFFER_SIZE, &n); copy = (ret == 1); trace_commit_one_iteration(s, offset, n, ret); diff --git a/block/io.c b/block/io.c index dfc153b..1ed4164 100644 --- a/block/io.c +++ b/block/io.c @@ -2317,7 +2317,8 @@ 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 + * between BASE and TOP (TOP included). To check the BASE image, set the + * 'include_base' to 'true'. The 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. * @@ -2331,14 +2332,17 @@ 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; @@ -2360,6 +2364,10 @@ int bdrv_is_allocated_above(BlockDriverState *top, n = pnum_inter; } + if (intermediate == base) { + break; + } + intermediate = backing_bs(intermediate); } diff --git a/block/mirror.c b/block/mirror.c index ff15cfb..923548f 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -807,7 +807,7 @@ static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s) return 0; } - ret = bdrv_is_allocated_above(bs, base, offset, bytes, &count); + ret = bdrv_is_allocated_above(bs, base, false, offset, bytes, &count); if (ret < 0) { return ret; } diff --git a/block/replication.c b/block/replication.c index 3d4dedd..fc8d2ad 100644 --- a/block/replication.c +++ b/block/replication.c @@ -272,7 +272,7 @@ static coroutine_fn int replication_co_writev(BlockDriverState *bs, while (remaining_sectors > 0) { int64_t count; - ret = bdrv_is_allocated_above(top->bs, base->bs, + ret = bdrv_is_allocated_above(top->bs, base->bs, false, sector_num * BDRV_SECTOR_SIZE, remaining_sectors * BDRV_SECTOR_SIZE, &count); diff --git a/block/stream.c b/block/stream.c index bfaebb8..0920092 100644 --- a/block/stream.c +++ b/block/stream.c @@ -162,7 +162,7 @@ static int coroutine_fn stream_run(Job *job, Error **errp) } else if (ret >= 0) { /* Copy if allocated in the intermediate images. Limit to the * known-unallocated area [offset, offset+n*BDRV_SECTOR_SIZE). */ - ret = bdrv_is_allocated_above(backing_bs(bs), base, + ret = bdrv_is_allocated_above(backing_bs(bs), base, false, offset, n, &n); /* Finish early if end of backing file has been reached */ diff --git a/include/block/block.h b/include/block/block.h index c7a2619..f98e858 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -447,7 +447,8 @@ int bdrv_block_status_above(BlockDriverState *bs, BlockDriverState *base, int bdrv_is_allocated(BlockDriverState *bs, int64_t offset, int64_t bytes, int64_t *pnum); 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); bool bdrv_is_read_only(BlockDriverState *bs); int bdrv_can_set_read_only(BlockDriverState *bs, bool read_only, -- 1.8.3.1