diff --git a/drivers/md/dm.c b/drivers/md/dm.c index edf9f2467691..36142e947ffc 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -164,6 +164,9 @@ struct mapped_device { /* sysfs handle */ struct kobject kobj; + + /* zero-length barrier that will be cloned and submitted to targets */ + struct bio barrier_bio; }; #define MIN_IOS 256 @@ -1477,6 +1480,13 @@ static int dm_wait_for_completion(struct mapped_device *md, int interruptible) static void dm_flush(struct mapped_device *md) { dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE); + + bio_init(&md->barrier_bio); + md->barrier_bio.bi_bdev = md->bdev; + md->barrier_bio.bi_rw = WRITE_BARRIER; + __split_and_process_bio(md, &md->barrier_bio); + + dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE); } static void process_barrier(struct mapped_device *md, struct bio *bio)