Commit 176c3699 authored by Fam Zheng's avatar Fam Zheng Committed by Jeff Cody
Browse files

mirror: Quiesce source during "mirror_exit" 



With dataplane, the ioeventfd events could be dispatched after
mirror_run releases the dirty bitmap, but before mirror_exit actually
does the device switch, because the iothread will still be running, and
it will cause silent data loss.

Fix this by adding a bdrv_drained_begin/end pair around the window, so
that no new external request will be handled.

Signed-off-by: default avatarFam Zheng <famz@redhat.com>
Signed-off-by: default avatarJeff Cody <jcody@redhat.com>
parent 9d7b969e

block/mirror.c

+4 −0
Original line number Diff line number Diff line
@@ -388,6 +388,7 @@ static void mirror_exit(BlockJob *job, void *opaque) 
    bdrv_unref(s->target);

    block_job_completed(&s->common, data->ret);

    g_free(data);

    bdrv_drained_end(src);

    bdrv_unref(src);

}
@@ -607,6 +608,9 @@ immediate_exit: 


    data = g_malloc(sizeof(*data));

    data->ret = ret;

    /* Before we switch to target in mirror_exit, make sure data doesn't

     * change. */

    bdrv_drained_begin(s->common.bs);

    block_job_defer_to_main_loop(&s->common, mirror_exit, data);

}