Not all callers of bdrv_set_backing_hd() know for sure that attaching the backing file will be allowed by the permission system. Return the error from the function rather than aborting.
Signed-off-by: Kevin Wolf <[email protected]> --- block.c | 27 ++++++++++++++++++++------- block/commit.c | 14 +++++++------- block/mirror.c | 16 +++++++++++++++- block/stream.c | 9 ++++++++- block/vvfat.c | 2 +- include/block/block.h | 3 ++- 6 files changed, 53 insertions(+), 18 deletions(-) diff --git a/block.c b/block.c index 33e6415..b3f03a4 100644 --- a/block.c +++ b/block.c @@ -1859,7 +1859,8 @@ static void bdrv_parent_cb_resize(BlockDriverState *bs) * Sets the backing file link of a BDS. A new reference is created; callers * which don't need their own reference any more must call bdrv_unref(). */ -void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd) +void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd, + Error **errp) { if (backing_hd) { bdrv_ref(backing_hd); @@ -1873,9 +1874,9 @@ void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd) bs->backing = NULL; goto out; } - /* FIXME Error handling */ + bs->backing = bdrv_attach_child(bs, backing_hd, "backing", &child_backing, - &error_abort); + errp); out: bdrv_refresh_limits(bs, NULL); @@ -1959,8 +1960,12 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, /* Hook up the backing file link; drop our reference, bs owns the * backing_hd reference now */ - bdrv_set_backing_hd(bs, backing_hd); + bdrv_set_backing_hd(bs, backing_hd, &local_err); bdrv_unref(backing_hd); + if (local_err) { + ret = -EINVAL; + goto free_exit; + } qdict_del(parent_options, bdref_key); @@ -2796,7 +2801,7 @@ static void bdrv_close(BlockDriverState *bs) bs->drv->bdrv_close(bs); bs->drv = NULL; - bdrv_set_backing_hd(bs, NULL); + bdrv_set_backing_hd(bs, NULL, &error_abort); if (bs->file != NULL) { bdrv_unref_child(bs, bs->file); @@ -2903,7 +2908,8 @@ void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top) bdrv_ref(bs_top); change_parent_backing_link(bs_top, bs_new); - bdrv_set_backing_hd(bs_new, bs_top); + /* FIXME Error handling */ + bdrv_set_backing_hd(bs_new, bs_top, &error_abort); bdrv_unref(bs_top); /* bs_new is now referenced by its new parents, we don't need the @@ -3051,6 +3057,7 @@ int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top, BlockDriverState *base, const char *backing_file_str) { BlockDriverState *new_top_bs = NULL; + Error *local_err = NULL; int ret = -EIO; if (!top->drv || !base->drv) { @@ -3083,7 +3090,13 @@ int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top, if (ret) { goto exit; } - bdrv_set_backing_hd(new_top_bs, base); + + bdrv_set_backing_hd(new_top_bs, base, &local_err); + if (local_err) { + ret = -EPERM; + error_report_err(local_err); + goto exit; + } ret = 0; exit: diff --git a/block/commit.c b/block/commit.c index b9ec363..9838e77 100644 --- a/block/commit.c +++ b/block/commit.c @@ -118,7 +118,7 @@ static void commit_complete(BlockJob *job, void *opaque) * filter driver from the backing chain. Do this as the final step so that * the 'consistent read' permission can be granted. */ if (remove_commit_top_bs) { - bdrv_set_backing_hd(overlay_bs, top); + bdrv_set_backing_hd(overlay_bs, top, &error_abort); } } @@ -313,8 +313,8 @@ void commit_start(const char *job_id, BlockDriverState *bs, goto fail; } - bdrv_set_backing_hd(commit_top_bs, top); - bdrv_set_backing_hd(overlay_bs, commit_top_bs); + bdrv_set_backing_hd(commit_top_bs, top, &error_abort); + bdrv_set_backing_hd(overlay_bs, commit_top_bs, &error_abort); s->commit_top_bs = commit_top_bs; bdrv_unref(commit_top_bs); @@ -386,7 +386,7 @@ fail: blk_unref(s->top); } if (commit_top_bs) { - bdrv_set_backing_hd(overlay_bs, top); + bdrv_set_backing_hd(overlay_bs, top, &error_abort); } block_job_unref(&s->common); } @@ -447,8 +447,8 @@ int bdrv_commit(BlockDriverState *bs) goto ro_cleanup; } - bdrv_set_backing_hd(commit_top_bs, backing_file_bs); - bdrv_set_backing_hd(bs, commit_top_bs); + bdrv_set_backing_hd(commit_top_bs, backing_file_bs, &error_abort); + bdrv_set_backing_hd(bs, commit_top_bs, &error_abort); ret = blk_insert_bs(backing, backing_file_bs, &local_err); if (ret < 0) { @@ -527,7 +527,7 @@ ro_cleanup: qemu_vfree(buf); if (backing_file_bs) { - bdrv_set_backing_hd(bs, backing_file_bs); + bdrv_set_backing_hd(bs, backing_file_bs, &error_abort); } bdrv_unref(commit_top_bs); blk_unref(src); diff --git a/block/mirror.c b/block/mirror.c index fa0c0e5..abbd847 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -887,6 +887,7 @@ static void mirror_complete(BlockJob *job, Error **errp) { MirrorBlockJob *s = container_of(job, MirrorBlockJob, common); BlockDriverState *src, *target; + Error *local_err = NULL; src = s->source; target = blk_bs(s->target); @@ -935,12 +936,25 @@ static void mirror_complete(BlockJob *job, Error **errp) if (s->backing_mode == MIRROR_SOURCE_BACKING_CHAIN) { BlockDriverState *backing = s->is_none_mode ? src : s->base; if (backing_bs(target) != backing) { - bdrv_set_backing_hd(target, backing); + bdrv_set_backing_hd(target, backing, &local_err); + if (local_err) { + error_propagate(errp, local_err); + goto fail; + } } } s->should_complete = true; block_job_enter(&s->common); + return; + +fail: + if (s->replaces) { + bdrv_unref(s->to_replace); + bdrv_op_unblock_all(s->to_replace, s->replace_blocker); + error_free(s->replace_blocker); + s->replace_blocker = NULL; + } } static void mirror_pause(BlockJob *job) diff --git a/block/stream.c b/block/stream.c index 0c30d41..bd3d2ce 100644 --- a/block/stream.c +++ b/block/stream.c @@ -68,6 +68,7 @@ static void stream_complete(BlockJob *job, void *opaque) StreamCompleteData *data = opaque; BlockDriverState *bs = blk_bs(job->blk); BlockDriverState *base = s->base; + Error *local_err = NULL; if (!block_job_is_cancelled(&s->common) && data->reached_end && data->ret == 0) { @@ -79,9 +80,15 @@ static void stream_complete(BlockJob *job, void *opaque) } } data->ret = bdrv_change_backing_file(bs, base_id, base_fmt); - bdrv_set_backing_hd(bs, base); + bdrv_set_backing_hd(bs, base, &local_err); + if (local_err) { + error_report_err(local_err); + data->ret = -EPERM; + goto out; + } } +out: /* Reopen the image back in read-only mode if necessary */ if (s->bs_flags != bdrv_get_flags(bs)) { bdrv_reopen(bs, s->bs_flags, NULL); diff --git a/block/vvfat.c b/block/vvfat.c index 72b482c..aa61c32 100644 --- a/block/vvfat.c +++ b/block/vvfat.c @@ -3041,7 +3041,7 @@ static int enable_write_target(BlockDriverState *bs, Error **errp) &error_abort); *(void**) backing->opaque = s; - bdrv_set_backing_hd(s->bs, backing); + bdrv_set_backing_hd(s->bs, backing, &error_abort); bdrv_unref(backing); return 0; diff --git a/include/block/block.h b/include/block/block.h index 701d22b..6a6408e 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -246,7 +246,8 @@ BdrvChild *bdrv_open_child(const char *filename, BlockDriverState* parent, const BdrvChildRole *child_role, bool allow_none, Error **errp); -void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd); +void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd, + Error **errp); int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, const char *bdref_key, Error **errp); BlockDriverState *bdrv_open(const char *filename, const char *reference, -- 1.8.3.1
