writeback: remove bdi->congested_fn

Except for pktdvd, the only places setting congested bits are file
systems that allocate their own backing_dev_info structures.  And
pktdvd is a deprecated driver that isn't useful in stack setup
either.  So remove the dead congested_fn stacking infrastructure.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Song Liu <song@kernel.org>
Acked-by: David Sterba <dsterba@suse.com>
[axboe: fixup unused variables in bcache/request.c]
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 0 insertions, 59 deletions

diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 7c34cc0ad8cc..cb687ccdbd96 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -2415,62 +2415,6 @@ static void drbd_cleanup(void)
 	pr_info("module cleanup done.\n");
 }
 
-/**
- * drbd_congested() - Callback for the flusher thread
- * @congested_data:	User data
- * @bdi_bits:		Bits the BDI flusher thread is currently interested in
- *
- * Returns 1<<WB_async_congested and/or 1<<WB_sync_congested if we are congested.
- */
-static int drbd_congested(void *congested_data, int bdi_bits)
-{
-	struct drbd_device *device = congested_data;
-	struct request_queue *q;
-	char reason = '-';
-	int r = 0;
-
-	if (!may_inc_ap_bio(device)) {
-		/* DRBD has frozen IO */
-		r = bdi_bits;
-		reason = 'd';
-		goto out;
-	}
-
-	if (test_bit(CALLBACK_PENDING, &first_peer_device(device)->connection->flags)) {
-		r |= (1 << WB_async_congested);
-		/* Without good local data, we would need to read from remote,
-		 * and that would need the worker thread as well, which is
-		 * currently blocked waiting for that usermode helper to
-		 * finish.
-		 */
-		if (!get_ldev_if_state(device, D_UP_TO_DATE))
-			r |= (1 << WB_sync_congested);
-		else
-			put_ldev(device);
-		r &= bdi_bits;
-		reason = 'c';
-		goto out;
-	}
-
-	if (get_ldev(device)) {
-		q = bdev_get_queue(device->ldev->backing_bdev);
-		r = bdi_congested(q->backing_dev_info, bdi_bits);
-		put_ldev(device);
-		if (r)
-			reason = 'b';
-	}
-
-	if (bdi_bits & (1 << WB_async_congested) &&
-	    test_bit(NET_CONGESTED, &first_peer_device(device)->connection->flags)) {
-		r |= (1 << WB_async_congested);
-		reason = reason == 'b' ? 'a' : 'n';
-	}
-
-out:
-	device->congestion_reason = reason;
-	return r;
-}
-
 static void drbd_init_workqueue(struct drbd_work_queue* wq)
 {
 	spin_lock_init(&wq->q_lock);
@@ -2825,9 +2769,6 @@ 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;
-
 	blk_queue_write_cache(q, true, true);
 	/* Setting the max_hw_sectors to an odd value of 8kibyte here
 	   This triggers a max_bio_size message upon first attach or connect */