md: raid1/raid10: drop pending_cnt

Those counters are not necessary after commit 11bb45e8aaf6 ("md: drop queue
limitation for RAID1 and RAID10"). Remove them from all code (conf and
plug structs). raid1_plug_cb and raid10_plug_cb are identical, so move
definition of raid1_plug_cb to common raid1-10 definitions and use it for
RAID10 too.
Signed-off-by: Mariusz Tkaczyk <mariusz.tkaczyk@linux.intel.com>
Signed-off-by: Song Liu <song@kernel.org>

drivers/md/raid1-10.c

@@ -28,6 +28,11 @@ struct resync_pages {
 	struct page	*pages[RESYNC_PAGES];
 };
 
+struct raid1_plug_cb {
+	struct blk_plug_cb	cb;
+	struct bio_list		pending;
+};
+
 static void rbio_pool_free(void *rbio, void *data)
 {
 	kfree(rbio);

drivers/md/raid1.c

@@ -824,7 +824,6 @@ static void flush_pending_writes(struct r1conf *conf)
 		struct bio *bio;
 
 		bio = bio_list_get(&conf->pending_bio_list);
-		conf->pending_count = 0;
 		spin_unlock_irq(&conf->device_lock);
 
 		/*
@@ -1167,12 +1166,6 @@ static void alloc_behind_master_bio(struct r1bio *r1_bio,
 	bio_put(behind_bio);
 }
 
-struct raid1_plug_cb {
-	struct blk_plug_cb	cb;
-	struct bio_list		pending;
-	int			pending_cnt;
-};
-
 static void raid1_unplug(struct blk_plug_cb *cb, bool from_schedule)
 {
 	struct raid1_plug_cb *plug = container_of(cb, struct raid1_plug_cb,
@@ -1184,7 +1177,6 @@ static void raid1_unplug(struct blk_plug_cb *cb, bool from_schedule)
 	if (from_schedule || current->bio_list) {
 		spin_lock_irq(&conf->device_lock);
 		bio_list_merge(&conf->pending_bio_list, &plug->pending);
-		conf->pending_count += plug->pending_cnt;
 		spin_unlock_irq(&conf->device_lock);
 		wake_up(&conf->wait_barrier);
 		md_wakeup_thread(mddev->thread);
@@ -1588,11 +1580,9 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio,
 			plug = NULL;
 		if (plug) {
 			bio_list_add(&plug->pending, mbio);
-			plug->pending_cnt++;
 		} else {
 			spin_lock_irqsave(&conf->device_lock, flags);
 			bio_list_add(&conf->pending_bio_list, mbio);
-			conf->pending_count++;
 			spin_unlock_irqrestore(&conf->device_lock, flags);
 			md_wakeup_thread(mddev->thread);
 		}
@@ -3058,7 +3048,6 @@ static struct r1conf *setup_conf(struct mddev *mddev)
 	init_waitqueue_head(&conf->wait_barrier);
 
 	bio_list_init(&conf->pending_bio_list);
-	conf->pending_count = 0;
 	conf->recovery_disabled = mddev->recovery_disabled - 1;
 
 	err = -EIO;

drivers/md/raid1.h

@@ -87,7 +87,6 @@ struct r1conf {
 
 	/* queue pending writes to be submitted on unplug */
 	struct bio_list		pending_bio_list;
-	int			pending_count;
 
 	/* for use when syncing mirrors:
 	 * We don't allow both normal IO and resync/recovery IO at

drivers/md/raid10.c

@@ -861,7 +861,6 @@ static void flush_pending_writes(struct r10conf *conf)
 		struct bio *bio;
 
 		bio = bio_list_get(&conf->pending_bio_list);
-		conf->pending_count = 0;
 		spin_unlock_irq(&conf->device_lock);
 
 		/*
@@ -1054,16 +1053,9 @@ static sector_t choose_data_offset(struct r10bio *r10_bio,
 		return rdev->new_data_offset;
 }
 
-struct raid10_plug_cb {
-	struct blk_plug_cb	cb;
-	struct bio_list		pending;
-	int			pending_cnt;
-};
-
 static void raid10_unplug(struct blk_plug_cb *cb, bool from_schedule)
 {
-	struct raid10_plug_cb *plug = container_of(cb, struct raid10_plug_cb,
-						   cb);
+	struct raid1_plug_cb *plug = container_of(cb, struct raid1_plug_cb, cb);
 	struct mddev *mddev = plug->cb.data;
 	struct r10conf *conf = mddev->private;
 	struct bio *bio;
@@ -1071,7 +1063,6 @@ static void raid10_unplug(struct blk_plug_cb *cb, bool from_schedule)
 	if (from_schedule || current->bio_list) {
 		spin_lock_irq(&conf->device_lock);
 		bio_list_merge(&conf->pending_bio_list, &plug->pending);
-		conf->pending_count += plug->pending_cnt;
 		spin_unlock_irq(&conf->device_lock);
 		wake_up(&conf->wait_barrier);
 		md_wakeup_thread(mddev->thread);
@@ -1238,7 +1229,7 @@ static void raid10_write_one_disk(struct mddev *mddev, struct r10bio *r10_bio,
 	const unsigned long do_fua = (bio->bi_opf & REQ_FUA);
 	unsigned long flags;
 	struct blk_plug_cb *cb;
-	struct raid10_plug_cb *plug = NULL;
+	struct raid1_plug_cb *plug = NULL;
 	struct r10conf *conf = mddev->private;
 	struct md_rdev *rdev;
 	int devnum = r10_bio->devs[n_copy].devnum;
@@ -1280,16 +1271,14 @@ static void raid10_write_one_disk(struct mddev *mddev, struct r10bio *r10_bio,
 
 	cb = blk_check_plugged(raid10_unplug, mddev, sizeof(*plug));
 	if (cb)
-		plug = container_of(cb, struct raid10_plug_cb, cb);
+		plug = container_of(cb, struct raid1_plug_cb, cb);
 	else
 		plug = NULL;
 	if (plug) {
 		bio_list_add(&plug->pending, mbio);
-		plug->pending_cnt++;
 	} else {
 		spin_lock_irqsave(&conf->device_lock, flags);
 		bio_list_add(&conf->pending_bio_list, mbio);
-		conf->pending_count++;
 		spin_unlock_irqrestore(&conf->device_lock, flags);
 		md_wakeup_thread(mddev->thread);
 	}

drivers/md/raid10.h

@@ -75,7 +75,6 @@ struct r10conf {
 
 	/* queue pending writes and submit them on unplug */
 	struct bio_list		pending_bio_list;
-	int			pending_count;
 
 	spinlock_t		resync_lock;
 	atomic_t		nr_pending;