diff options
| -rw-r--r-- | block.c | 30 | ||||
| -rw-r--r-- | block/block-backend.c | 3 | ||||
| -rw-r--r-- | block/quorum.c | 1 | ||||
| -rw-r--r-- | blockjob.c | 2 |
4 files changed, 20 insertions, 16 deletions
@@ -2243,6 +2243,13 @@ static void bdrv_replace_child(BdrvChild *child, BlockDriverState *new_bs) } } +/* + * This function steals the reference to child_bs from the caller. + * That reference is later dropped by bdrv_root_unref_child(). + * + * On failure NULL is returned, errp is set and the reference to + * child_bs is also dropped. + */ BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs, const char *child_name, const BdrvChildRole *child_role, @@ -2255,6 +2262,7 @@ BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs, ret = bdrv_check_update_perm(child_bs, NULL, perm, shared_perm, NULL, errp); if (ret < 0) { bdrv_abort_perm_update(child_bs); + bdrv_unref(child_bs); return NULL; } @@ -2274,6 +2282,14 @@ BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs, return child; } +/* + * This function transfers the reference to child_bs from the caller + * to parent_bs. That reference is later dropped by parent_bs on + * bdrv_close() or if someone calls bdrv_unref_child(). + * + * On failure NULL is returned, errp is set and the reference to + * child_bs is also dropped. + */ BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs, BlockDriverState *child_bs, const char *child_name, @@ -2401,12 +2417,9 @@ void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd, /* If backing_hd was already part of bs's backing chain, and * inherits_from pointed recursively to bs then let's update it to * point directly to bs (else it will become NULL). */ - if (update_inherits_from) { + if (bs->backing && update_inherits_from) { backing_hd->inherits_from = bs; } - if (!bs->backing) { - bdrv_unref(backing_hd); - } out: bdrv_refresh_limits(bs, NULL); @@ -2594,7 +2607,6 @@ BdrvChild *bdrv_open_child(const char *filename, const BdrvChildRole *child_role, bool allow_none, Error **errp) { - BdrvChild *c; BlockDriverState *bs; bs = bdrv_open_child_bs(filename, options, bdref_key, parent, child_role, @@ -2603,13 +2615,7 @@ BdrvChild *bdrv_open_child(const char *filename, return NULL; } - c = bdrv_attach_child(parent, bs, bdref_key, child_role, errp); - if (!c) { - bdrv_unref(bs); - return NULL; - } - - return c; + return bdrv_attach_child(parent, bs, bdref_key, child_role, errp); } /* TODO Future callers may need to specify parent/child_role in order for diff --git a/block/block-backend.c b/block/block-backend.c index 4c0a8ef88d..ad3e1c882d 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -392,7 +392,6 @@ BlockBackend *blk_new_open(const char *filename, const char *reference, blk->root = bdrv_root_attach_child(bs, "root", &child_root, perm, BLK_PERM_ALL, blk, errp); if (!blk->root) { - bdrv_unref(bs); blk_unref(blk); return NULL; } @@ -800,12 +799,12 @@ void blk_remove_bs(BlockBackend *blk) int blk_insert_bs(BlockBackend *blk, BlockDriverState *bs, Error **errp) { ThrottleGroupMember *tgm = &blk->public.throttle_group_member; + bdrv_ref(bs); blk->root = bdrv_root_attach_child(bs, "root", &child_root, blk->perm, blk->shared_perm, blk, errp); if (blk->root == NULL) { return -EPERM; } - bdrv_ref(bs); notifier_list_notify(&blk->insert_bs_notifiers, blk); if (tgm->throttle_state) { diff --git a/block/quorum.c b/block/quorum.c index 352f729136..133ee18204 100644 --- a/block/quorum.c +++ b/block/quorum.c @@ -1019,7 +1019,6 @@ static void quorum_add_child(BlockDriverState *bs, BlockDriverState *child_bs, child = bdrv_attach_child(bs, child_bs, indexstr, &child_format, errp); if (child == NULL) { s->next_child_index--; - bdrv_unref(child_bs); goto out; } s->children = g_renew(BdrvChild *, s->children, s->num_children + 1); diff --git a/blockjob.c b/blockjob.c index 9ca942ba01..cc5f18e7cd 100644 --- a/blockjob.c +++ b/blockjob.c @@ -204,6 +204,7 @@ int block_job_add_bdrv(BlockJob *job, const char *name, BlockDriverState *bs, { BdrvChild *c; + bdrv_ref(bs); c = bdrv_root_attach_child(bs, name, &child_job, perm, shared_perm, job, errp); if (c == NULL) { @@ -211,7 +212,6 @@ int block_job_add_bdrv(BlockJob *job, const char *name, BlockDriverState *bs, } job->nodes = g_slist_prepend(job->nodes, c); - bdrv_ref(bs); bdrv_op_block_all(bs, job->blocker); return 0; |