From: Kevin Wolf <kwolf@redhat.com>
Date: Mon, 11 Sep 2023 09:46:17 +0000 (+0200)
Subject: block: Take graph rdlock in bdrv_change_aio_context()
X-Git-Tag: v8.2.0-rc0~115^2~10
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=7f831d29e3d005e499b22c0591a26a33eb5c406d;p=thirdparty%2Fqemu.git

block: Take graph rdlock in bdrv_change_aio_context()

The function reads the parents list, so it needs to hold the graph lock.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Message-ID: <20230911094620.45040-19-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---

diff --git a/block.c b/block.c
index e024a6ccece..8e589bb2e49 100644
--- a/block.c
+++ b/block.c
@@ -7688,17 +7688,21 @@ static bool bdrv_change_aio_context(BlockDriverState *bs, AioContext *ctx,
         return true;
     }
 
+    bdrv_graph_rdlock_main_loop();
     QLIST_FOREACH(c, &bs->parents, next_parent) {
         if (!bdrv_parent_change_aio_context(c, ctx, visited, tran, errp)) {
+            bdrv_graph_rdunlock_main_loop();
             return false;
         }
     }
 
     QLIST_FOREACH(c, &bs->children, next) {
         if (!bdrv_child_change_aio_context(c, ctx, visited, tran, errp)) {
+            bdrv_graph_rdunlock_main_loop();
             return false;
         }
     }
+    bdrv_graph_rdunlock_main_loop();
 
     state = g_new(BdrvStateSetAioContext, 1);
     *state = (BdrvStateSetAioContext) {