block: Fix AioContext locking in bdrv_open_backing_file()

bdrv_set_backing() requires the caller to hold the AioContext lock for
@backing_hd. Take it in bdrv_open_backing_file() before calling the
function.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230605085711.21261-9-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
master
Kevin Wolf 2023-06-05 10:57:08 +02:00
parent f665f01f72
commit 8aa0454219
1 changed files with 5 additions and 0 deletions

View File

@ -3526,6 +3526,7 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options,
int ret = 0;
bool implicit_backing = false;
BlockDriverState *backing_hd;
AioContext *backing_hd_ctx;
QDict *options;
QDict *tmp_parent_options = NULL;
Error *local_err = NULL;
@ -3610,8 +3611,12 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options,
/* Hook up the backing file link; drop our reference, bs owns the
* backing_hd reference now */
backing_hd_ctx = bdrv_get_aio_context(backing_hd);
aio_context_acquire(backing_hd_ctx);
ret = bdrv_set_backing_hd(bs, backing_hd, errp);
bdrv_unref(backing_hd);
aio_context_release(backing_hd_ctx);
if (ret < 0) {
goto free_exit;
}