block: Use pointer to backing_dev_info from request_queue

We will want to have struct backing_dev_info allocated separately from
struct request_queue. As the first step add pointer to backing_dev_info
to request_queue and convert all users touching it. No functional
changes in this patch.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>

4 files changed, 12 insertions, 10 deletions

diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 83482721bc01..d305f05be648 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -2462,7 +2462,7 @@ static int drbd_congested(void *congested_data, int bdi_bits)
 
 	if (get_ldev(device)) {
 		q = bdev_get_queue(device->ldev->backing_bdev);
-		r = bdi_congested(&q->backing_dev_info, bdi_bits);
+		r = bdi_congested(q->backing_dev_info, bdi_bits);
 		put_ldev(device);
 		if (r)
 			reason = 'b';
@@ -2834,8 +2834,8 @@ enum drbd_ret_code drbd_create_device(struct drbd_config_context *adm_ctx, unsig
 	/* we have no partitions. we contain only ourselves. */
 	device->this_bdev->bd_contains = device->this_bdev;
 
-	q->backing_dev_info.congested_fn = drbd_congested;
-	q->backing_dev_info.congested_data = device;
+	q->backing_dev_info->congested_fn = drbd_congested;
+	q->backing_dev_info->congested_data = device;
 
 	blk_queue_make_request(q, drbd_make_request);
 	blk_queue_write_cache(q, true, true);
diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index f35db29cac76..908c704e20aa 100644
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -1328,11 +1328,13 @@ static void drbd_setup_queue_param(struct drbd_device *device, struct drbd_backi
 	if (b) {
 		blk_queue_stack_limits(q, b);
 
-		if (q->backing_dev_info.ra_pages != b->backing_dev_info.ra_pages) {
+		if (q->backing_dev_info->ra_pages !=
+		    b->backing_dev_info->ra_pages) {
 			drbd_info(device, "Adjusting my ra_pages to backing device's (%lu -> %lu)\n",
-				 q->backing_dev_info.ra_pages,
-				 b->backing_dev_info.ra_pages);
-			q->backing_dev_info.ra_pages = b->backing_dev_info.ra_pages;
+				 q->backing_dev_info->ra_pages,
+				 b->backing_dev_info->ra_pages);
+			q->backing_dev_info->ra_pages =
+						b->backing_dev_info->ra_pages;
 		}
 	}
 	fixup_discard_if_not_supported(q);
@@ -3345,7 +3347,7 @@ static void device_to_statistics(struct device_statistics *s,
 		s->dev_disk_flags = md->flags;
 		q = bdev_get_queue(device->ldev->backing_bdev);
 		s->dev_lower_blocked =
-			bdi_congested(&q->backing_dev_info,
+			bdi_congested(q->backing_dev_info,
 				      (1 << WB_async_congested) |
 				      (1 << WB_sync_congested));
 		put_ldev(device);
diff --git a/drivers/block/drbd/drbd_proc.c b/drivers/block/drbd/drbd_proc.c
index be2b93fd2c11..8378142f7a55 100644
--- a/drivers/block/drbd/drbd_proc.c
+++ b/drivers/block/drbd/drbd_proc.c
@@ -288,7 +288,7 @@ static int drbd_seq_show(struct seq_file *seq, void *v)
 			seq_printf(seq, "%2d: cs:Unconfigured\n", i);
 		} else {
 			/* reset device->congestion_reason */
-			bdi_rw_congested(&device->rq_queue->backing_dev_info);
+			bdi_rw_congested(device->rq_queue->backing_dev_info);
 
 			nc = rcu_dereference(first_peer_device(device)->connection->net_conf);
 			wp = nc ? nc->wire_protocol - DRBD_PROT_A + 'A' : ' ';
diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c
index de279fe4e4fd..cb6bdb75d52d 100644
--- a/drivers/block/drbd/drbd_req.c
+++ b/drivers/block/drbd/drbd_req.c
@@ -938,7 +938,7 @@ static bool remote_due_to_read_balancing(struct drbd_device *device, sector_t se
 
 	switch (rbm) {
 	case RB_CONGESTED_REMOTE:
-		bdi = &device->ldev->backing_bdev->bd_disk->queue->backing_dev_info;
+		bdi = device->ldev->backing_bdev->bd_disk->queue->backing_dev_info;
 		return bdi_read_congested(bdi);
 	case RB_LEAST_PENDING:
 		return atomic_read(&device->local_cnt) >