commit 8089eab2bd5fb160b038e64e14cf7ffb3f37091e
author Kevin Wolf <kwolf@redhat.com> Thu Dec 03 18:23:10 2020 +0100
committer Kevin Wolf <kwolf@redhat.com> Fri Dec 11 17:52:40 2020 +0100
tree 1b2531bb62869445e4013f964e7041319ac0709e
parent d9dbf25f9624aac43e4357019bed4422f0b3368d

block: Fix locking in qmp_block_resize()

The drain functions assume that we hold the AioContext lock of the
drained block node. Make sure to actually take the lock.

Cc: qemu-stable@nongnu.org
Fixes: eb94b81a94bce112e6b206df846c1551aaf6cab6
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20201203172311.68232-3-kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

blockdev.c

diff --git a/blockdev.c b/blockdev.c
index 660c735..412354b 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -2481,13 +2481,16 @@
         return;
     }
 
+    bdrv_co_lock(bs);
     bdrv_drained_begin(bs);
+    bdrv_co_unlock(bs);
+
     old_ctx = bdrv_co_enter(bs);
     blk_truncate(blk, size, false, PREALLOC_MODE_OFF, 0, errp);
     bdrv_co_leave(bs, old_ctx);
-    bdrv_drained_end(bs);
 
     bdrv_co_lock(bs);
+    bdrv_drained_end(bs);
     blk_unref(blk);
     bdrv_co_unlock(bs);
 }