Request coalescing logic is dependent on flush time update in other
context. This patch adds comments to understand the code flow better.
Signed-off-by: Pankaj Gupta <pankaj.gupta@cloud.ionos.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
{
ktime_t req_start = ktime_get_boottime();
spin_lock_irq(&mddev->lock);
+ /* flush requests wait until ongoing flush completes,
+ * hence coalescing all the pending requests.
+ */
wait_event_lock_irq(mddev->sb_wait,
!mddev->flush_bio ||
ktime_after(mddev->prev_flush_start, req_start),
mddev->lock);
+ /* new request after previous flush is completed */
if (!ktime_after(mddev->prev_flush_start, req_start)) {
WARN_ON(mddev->flush_bio);
mddev->flush_bio = bio;