block: Take main AioContext lock when calling bdrv_open()

The function documentation already says that all callers must hold the
main AioContext lock, but not all of them do. This can cause assertion
failures when functions called by bdrv_open() try to drop the lock. Fix
a few more callers to take the lock before calling bdrv_open().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230525124713.401149-4-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/qemu-nbd.c b/qemu-nbd.c
index 6ff4530..4276163 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -1071,7 +1071,11 @@ int main(int argc, char **argv)
         qdict_put_str(raw_opts, "driver", "raw");
         qdict_put_str(raw_opts, "file", bs->node_name);
         qdict_put_int(raw_opts, "offset", dev_offset);
+
+        aio_context_acquire(qemu_get_aio_context());
         bs = bdrv_open(NULL, NULL, raw_opts, flags, &error_fatal);
+        aio_context_release(qemu_get_aio_context());
+
         blk_remove_bs(blk);
         blk_insert_bs(blk, bs, &error_fatal);
         bdrv_unref(bs);