From bd8f4c42c8547a74b0f92dc17af93c3247c69f18 Mon Sep 17 00:00:00 2001 From: Vladimir Sementsov-Ogievskiy Date: Tue, 24 Aug 2021 11:38:23 +0300 Subject: [PATCH] block: introduce bdrv_replace_child_bs() Add function to transactionally replace bs inside BdrvChild. Signed-off-by: Vladimir Sementsov-Ogievskiy Reviewed-by: Max Reitz Message-Id: <20210824083856.17408-2-vsementsov@virtuozzo.com> Signed-off-by: Hanna Reitz --- block.c | 31 +++++++++++++++++++++++++++++++ include/block/block.h | 2 ++ 2 files changed, 33 insertions(+) diff --git a/block.c b/block.c index e97ce0b1c8..b2b66263f9 100644 --- a/block.c +++ b/block.c @@ -5048,6 +5048,37 @@ out: return ret; } +/* Not for empty child */ +int bdrv_replace_child_bs(BdrvChild *child, BlockDriverState *new_bs, + Error **errp) +{ + int ret; + Transaction *tran = tran_new(); + g_autoptr(GHashTable) found = NULL; + g_autoptr(GSList) refresh_list = NULL; + BlockDriverState *old_bs = child->bs; + + bdrv_ref(old_bs); + bdrv_drained_begin(old_bs); + bdrv_drained_begin(new_bs); + + bdrv_replace_child_tran(child, new_bs, tran); + + found = g_hash_table_new(NULL, NULL); + refresh_list = bdrv_topological_dfs(refresh_list, found, old_bs); + refresh_list = bdrv_topological_dfs(refresh_list, found, new_bs); + + ret = bdrv_list_refresh_perms(refresh_list, NULL, tran, errp); + + tran_finalize(tran, ret); + + bdrv_drained_end(old_bs); + bdrv_drained_end(new_bs); + bdrv_unref(old_bs); + + return ret; +} + static void bdrv_delete(BlockDriverState *bs) { assert(bdrv_op_blocker_is_empty(bs)); diff --git a/include/block/block.h b/include/block/block.h index 3477290f9a..740038a892 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -361,6 +361,8 @@ int bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top, Error **errp); int bdrv_replace_node(BlockDriverState *from, BlockDriverState *to, Error **errp); +int bdrv_replace_child_bs(BdrvChild *child, BlockDriverState *new_bs, + Error **errp); BlockDriverState *bdrv_insert_node(BlockDriverState *bs, QDict *node_options, int flags, Error **errp); int bdrv_drop_filter(BlockDriverState *bs, Error **errp);