@@ -427,6 +427,7 @@ static void submit_flushes(struct work_struct *ws)
struct mddev *mddev = container_of(ws, struct mddev, flush_work);
struct md_rdev *rdev;
+ mddev->start_flush = ktime_get_boottime();
INIT_WORK(&mddev->flush_work, md_submit_flush_data);
atomic_set(&mddev->flush_pending, 1);
rcu_read_lock();
@@ -467,6 +468,7 @@ static void md_submit_flush_data(struct work_struct *ws)
* could wait for this and below md_handle_request could wait for those
* bios because of suspend check
*/
+ mddev->last_flush = mddev->start_flush;
mddev->flush_bio = NULL;
wake_up(&mddev->sb_wait);
@@ -481,15 +483,32 @@ static void md_submit_flush_data(struct work_struct *ws)
void md_flush_request(struct mddev *mddev, struct bio *bio)
{
+ ktime_t start = ktime_get_boottime();
spin_lock_irq(&mddev->lock);
wait_event_lock_irq(mddev->sb_wait,
- !mddev->flush_bio,
+ !mddev->flush_bio ||
+ ktime_after(mddev->last_flush, start),
mddev->lock);
- mddev->flush_bio = bio;
+ if (!ktime_after(mddev->last_flush, start)) {
+ WARN_ON(mddev->flush_bio);
+ mddev->flush_bio = bio;
+ bio = NULL;
+ }
spin_unlock_irq(&mddev->lock);
- INIT_WORK(&mddev->flush_work, submit_flushes);
- queue_work(md_wq, &mddev->flush_work);
+ if (!bio) {
+ INIT_WORK(&mddev->flush_work, submit_flushes);
+ queue_work(md_wq, &mddev->flush_work);
+ } else {
+ /* flush was performed for some other bio while we waited. */
+ if (bio->bi_iter.bi_size == 0)
+ /* an empty barrier - all done */
+ bio_endio(bio);
+ else {
+ bio->bi_opf &= ~REQ_PREFLUSH;
+ mddev->pers->make_request(mddev, bio);
+ }
+ }
}
EXPORT_SYMBOL(md_flush_request);
@@ -463,6 +463,9 @@ struct mddev {
*/
struct bio *flush_bio;
atomic_t flush_pending;
+ ktime_t start_flush, last_flush; /* last_flush is when the last completed
+ * flush was started.
+ */
struct work_struct flush_work;
struct work_struct event_work; /* used by dm to report failure event */
void (*sync_super)(struct mddev *mddev, struct md_rdev *rdev);