Merge branch 'for-4.4/io-poll' of git://git.kernel.dk/linux-block

Pull block IO poll support from Jens Axboe:
 "Various groups have been doing experimentation around IO polling for
  (really) fast devices.  The code has been reviewed and has been
  sitting on the side for a few releases, but this is now good enough
  for coordinated benchmarking and further experimentation.

  Currently O_DIRECT sync read/write are supported.  A framework is in
  the works that allows scalable stats tracking so we can auto-tune
  this.  And we'll add libaio support as well soon.  Fow now, it's an
  opt-in feature for test purposes"

* 'for-4.4/io-poll' of git://git.kernel.dk/linux-block:
  direct-io: be sure to assign dio->bio_bdev for both paths
  directio: add block polling support
  NVMe: add blk polling support
  block: add block polling support
  blk-mq: return tag/queue combo in the make_request_fn handlers
  block: change ->make_request_fn() and users to return a queue cookie

3 files changed, 16 insertions, 9 deletions

diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c
index 8e9877b04637..25fa8445bb24 100644
--- a/drivers/md/bcache/request.c
+++ b/drivers/md/bcache/request.c
@@ -958,7 +958,8 @@ static void cached_dev_nodata(struct closure *cl)
 
 /* Cached devices - read & write stuff */
 
-static void cached_dev_make_request(struct request_queue *q, struct bio *bio)
+static blk_qc_t cached_dev_make_request(struct request_queue *q,
+                                        struct bio *bio)
 {
         struct search *s;
         struct bcache_device *d = bio->bi_bdev->bd_disk->private_data;
@@ -997,6 +998,8 @@ static void cached_dev_make_request(struct request_queue *q, struct bio *bio)
                 else
                         generic_make_request(bio);
         }
+
+        return BLK_QC_T_NONE;
 }
 
 static int cached_dev_ioctl(struct bcache_device *d, fmode_t mode,
@@ -1070,7 +1073,8 @@ static void flash_dev_nodata(struct closure *cl)
         continue_at(cl, search_free, NULL);
 }
 
-static void flash_dev_make_request(struct request_queue *q, struct bio *bio)
+static blk_qc_t flash_dev_make_request(struct request_queue *q,
+                                             struct bio *bio)
 {
         struct search *s;
         struct closure *cl;
@@ -1093,7 +1097,7 @@ static void flash_dev_make_request(struct request_queue *q, struct bio *bio)
                 continue_at_nobarrier(&s->cl,
                                       flash_dev_nodata,
                                       bcache_wq);
-                return;
+                return BLK_QC_T_NONE;
         } else if (rw) {
                 bch_keybuf_check_overlapping(&s->iop.c->moving_gc_keys,
                                         &KEY(d->id, bio->bi_iter.bi_sector, 0),
@@ -1109,6 +1113,7 @@ static void flash_dev_make_request(struct request_queue *q, struct bio *bio)
         }
 
         continue_at(cl, search_free, NULL);
+        return BLK_QC_T_NONE;
 }
 
 static int flash_dev_ioctl(struct bcache_device *d, fmode_t mode,
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 32440ad5f684..6e15f3565892 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1755,7 +1755,7 @@ static void __split_and_process_bio(struct mapped_device *md,
  * The request function that just remaps the bio built up by
  * dm_merge_bvec.
  */
-static void dm_make_request(struct request_queue *q, struct bio *bio)
+static blk_qc_t dm_make_request(struct request_queue *q, struct bio *bio)
 {
         int rw = bio_data_dir(bio);
         struct mapped_device *md = q->queuedata;
@@ -1774,12 +1774,12 @@ static void dm_make_request(struct request_queue *q, struct bio *bio)
                         queue_io(md, bio);
                 else
                         bio_io_error(bio);
-                return;
+                return BLK_QC_T_NONE;
         }
 
         __split_and_process_bio(md, map, bio);
         dm_put_live_table(md, srcu_idx);
-        return;
+        return BLK_QC_T_NONE;
 }
 
 int dm_request_based(struct mapped_device *md)
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 3f9a514b5b9d..807095f4c793 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -250,7 +250,7 @@ static DEFINE_SPINLOCK(all_mddevs_lock);
  * call has finished, the bio has been linked into some internal structure
  * and so is visible to ->quiesce(), so we don't need the refcount any more.
  */
-static void md_make_request(struct request_queue *q, struct bio *bio)
+static blk_qc_t md_make_request(struct request_queue *q, struct bio *bio)
 {
         const int rw = bio_data_dir(bio);
         struct mddev *mddev = q->queuedata;
@@ -262,13 +262,13 @@ static void md_make_request(struct request_queue *q, struct bio *bio)
         if (mddev == NULL || mddev->pers == NULL
             || !mddev->ready) {
                 bio_io_error(bio);
-                return;
+                return BLK_QC_T_NONE;
         }
         if (mddev->ro == 1 && unlikely(rw == WRITE)) {
                 if (bio_sectors(bio) != 0)
                         bio->bi_error = -EROFS;
                 bio_endio(bio);
-                return;
+                return BLK_QC_T_NONE;
         }
         smp_rmb(); /* Ensure implications of  'active' are visible */
         rcu_read_lock();
@@ -302,6 +302,8 @@ static void md_make_request(struct request_queue *q, struct bio *bio)
 
         if (atomic_dec_and_test(&mddev->active_io) && mddev->suspended)
                 wake_up(&mddev->sb_wait);
+
+        return BLK_QC_T_NONE;
 }
 
 /* mddev_suspend makes sure no new requests are submitted