From: Kevin Wolf Date: Tue, 4 Feb 2025 21:14:02 +0000 (+0100) Subject: block: Drain nodes before inactivating them X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=2849092a0024405e74c96f0a5ec41bb182ec8538;p=qemu.git block: Drain nodes before inactivating them So far the assumption has always been that if we try to inactivate a node, it is already idle. This doesn't hold true any more if we allow inactivating exported nodes because we can't know when new external requests come in. Drain the node around setting BDRV_O_INACTIVE so that requests can't start operating on an active node and then in the middle it suddenly becomes inactive. With this change, it's enough for exports to check for new requests that they operate on an active node (or, like reads, are allowed even on an inactive node). Signed-off-by: Kevin Wolf Acked-by: Fabiano Rosas Message-ID: <20250204211407.381505-12-kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi Reviewed-by: Eric Blake Signed-off-by: Kevin Wolf --- diff --git a/block.c b/block.c index 7eeb8d076e..1601b25f66 100644 --- a/block.c +++ b/block.c @@ -7032,7 +7032,9 @@ bdrv_inactivate_recurse(BlockDriverState *bs, bool top_level) return -EPERM; } + bdrv_drained_begin(bs); bs->open_flags |= BDRV_O_INACTIVE; + bdrv_drained_end(bs); /* * Update permissions, they may differ for inactive nodes.