diff options
| -rw-r--r-- | block/snapshot.c | 38 |
1 files changed, 16 insertions, 22 deletions
diff --git a/block/snapshot.c b/block/snapshot.c index f3971ac2bd..e22ac3eac6 100644 --- a/block/snapshot.c +++ b/block/snapshot.c @@ -151,34 +151,29 @@ bool bdrv_snapshot_find_by_id_and_name(BlockDriverState *bs, } /** - * Return a pointer to the child BDS pointer to which we can fall + * Return a pointer to child of given BDS to which we can fall * back if the given BDS does not support snapshots. * Return NULL if there is no BDS to (safely) fall back to. - * - * We need to return an indirect pointer because bdrv_snapshot_goto() - * has to modify the BdrvChild pointer. */ -static BdrvChild **bdrv_snapshot_fallback_ptr(BlockDriverState *bs) +static BdrvChild *bdrv_snapshot_fallback_child(BlockDriverState *bs) { - BdrvChild **fallback; - BdrvChild *child = bdrv_primary_child(bs); + BdrvChild *fallback = bdrv_primary_child(bs); + BdrvChild *child; /* We allow fallback only to primary child */ - if (!child) { + if (!fallback) { return NULL; } - fallback = (child == bs->file ? &bs->file : &bs->backing); - assert(*fallback == child); /* * Check that there are no other children that would need to be * snapshotted. If there are, it is not safe to fall back to - * *fallback. + * fallback. */ QLIST_FOREACH(child, &bs->children, next) { if (child->role & (BDRV_CHILD_DATA | BDRV_CHILD_METADATA | BDRV_CHILD_FILTERED) && - child != *fallback) + child != fallback) { return NULL; } @@ -189,8 +184,7 @@ static BdrvChild **bdrv_snapshot_fallback_ptr(BlockDriverState *bs) static BlockDriverState *bdrv_snapshot_fallback(BlockDriverState *bs) { - BdrvChild **child_ptr = bdrv_snapshot_fallback_ptr(bs); - return child_ptr ? (*child_ptr)->bs : NULL; + return child_bs(bdrv_snapshot_fallback_child(bs)); } int bdrv_can_snapshot(BlockDriverState *bs) @@ -237,7 +231,7 @@ int bdrv_snapshot_goto(BlockDriverState *bs, Error **errp) { BlockDriver *drv = bs->drv; - BdrvChild **fallback_ptr; + BdrvChild *fallback; int ret, open_ret; GLOBAL_STATE_CODE(); @@ -260,13 +254,13 @@ int bdrv_snapshot_goto(BlockDriverState *bs, return ret; } - fallback_ptr = bdrv_snapshot_fallback_ptr(bs); - if (fallback_ptr) { + fallback = bdrv_snapshot_fallback_child(bs); + if (fallback) { QDict *options; QDict *file_options; Error *local_err = NULL; - BlockDriverState *fallback_bs = (*fallback_ptr)->bs; - char *subqdict_prefix = g_strdup_printf("%s.", (*fallback_ptr)->name); + BlockDriverState *fallback_bs = fallback->bs; + char *subqdict_prefix = g_strdup_printf("%s.", fallback->name); options = qdict_clone_shallow(bs->options); @@ -277,8 +271,8 @@ int bdrv_snapshot_goto(BlockDriverState *bs, qobject_unref(file_options); g_free(subqdict_prefix); - /* Force .bdrv_open() below to re-attach fallback_bs on *fallback_ptr */ - qdict_put_str(options, (*fallback_ptr)->name, + /* Force .bdrv_open() below to re-attach fallback_bs on fallback */ + qdict_put_str(options, fallback->name, bdrv_get_node_name(fallback_bs)); /* Now close bs, apply the snapshot on fallback_bs, and re-open bs */ @@ -287,7 +281,7 @@ int bdrv_snapshot_goto(BlockDriverState *bs, } /* .bdrv_open() will re-attach it */ - bdrv_unref_child(bs, *fallback_ptr); + bdrv_unref_child(bs, fallback); ret = bdrv_snapshot_goto(fallback_bs, snapshot_id, errp); open_ret = drv->bdrv_open(bs, options, bs->open_flags, &local_err); |