block: introduce dirty_bitmap_mutex

It protects only the list of dirty bitmaps; in the next patch we will
also protect their content.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20170605123908.18777-15-pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/block.c b/block.c
index a5cbd4540f..694396281b 100644
--- a/block.c
+++ b/block.c
@@ -321,6 +321,7 @@ BlockDriverState *bdrv_new(void)
     }
     notifier_with_return_list_init(&bs->before_write_notifiers);
     qemu_co_mutex_init(&bs->reqs_lock);
+    qemu_mutex_init(&bs->dirty_bitmap_mutex);
     bs->refcnt = 1;
     bs->aio_context = qemu_get_aio_context();