From 0a2c96ee5a3463e82397afb9cb36f340a93264c2 Mon Sep 17 00:00:00 2001
From: WangJian <wangjian161@huawei.com>
Date: Wed, 9 Feb 2022 11:29:15 +0800
Subject: [PATCH] block: disallow block jobs when there is a BDRV_O_INACTIVE
 flag

Currently, migration will put a BDRV_O_INACTIVE flag
on bs's open_flags until another resume being called. In that case,
any IO from vm or block jobs will cause a qemu crash with an assert
'assert(!(bs->open_flags & BDRV_O_INACTIVE))' failure in bdrv_co_pwritev
function. we hereby disallow block jobs by faking a blocker.

Signed-off-by: wangjian161 <wangjian161@huawei.com>
---
 block.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/block.c b/block.c
index 0ac5b163d2..26c3982567 100644
--- a/block.c
+++ b/block.c
@@ -6692,6 +6692,22 @@ bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp)
                                 bdrv_get_device_or_node_name(bs));
         return true;
     }
+
+    /*
+     * When migration puts a BDRV_O_INACTIVE flag on driver's open_flags,
+     * we fake a blocker that doesn't exist. From now on, block jobs
+     * will not be permitted.
+     */
+    if ((op == BLOCK_OP_TYPE_RESIZE || op == BLOCK_OP_TYPE_COMMIT_SOURCE ||
+         op == BLOCK_OP_TYPE_MIRROR_SOURCE || op == BLOCK_OP_TYPE_MIRROR_TARGET) &&
+         (bs->open_flags & BDRV_O_INACTIVE)) {
+        if (errp) {
+            error_setg(errp, "block device is in use by migration with"
+                       " a driver BDRV_O_INACTIVE flag setted");
+        }
+        return true;
+    }
+
     return false;
 }
 
-- 
2.27.0