diff --git a/Makefile b/Makefile
index 31f967c..2652089 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 VERSION = 3
 PATCHLEVEL = 1
 SUBLEVEL = 0
-EXTRAVERSION = -rc9
+EXTRAVERSION = -rc10
 NAME = "Divemaster Edition"
 
 # *DOCUMENTATION*
diff --git a/arch/m68k/emu/nfblock.c b/arch/m68k/emu/nfblock.c
index 48e50f8..e301133 100644
--- a/arch/m68k/emu/nfblock.c
+++ b/arch/m68k/emu/nfblock.c
@@ -59,7 +59,7 @@
 	struct gendisk *disk;
 };
 
-static int nfhd_make_request(struct request_queue *queue, struct bio *bio)
+static void nfhd_make_request(struct request_queue *queue, struct bio *bio)
 {
 	struct nfhd_device *dev = queue->queuedata;
 	struct bio_vec *bvec;
@@ -76,7 +76,6 @@
 		sec += len;
 	}
 	bio_endio(bio, 0);
-	return 0;
 }
 
 static int nfhd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
diff --git a/arch/powerpc/sysdev/axonram.c b/arch/powerpc/sysdev/axonram.c
index 265f0f0..ba42719 100644
--- a/arch/powerpc/sysdev/axonram.c
+++ b/arch/powerpc/sysdev/axonram.c
@@ -104,7 +104,7 @@
  * axon_ram_make_request - make_request() method for block device
  * @queue, @bio: see blk_queue_make_request()
  */
-static int
+static void
 axon_ram_make_request(struct request_queue *queue, struct bio *bio)
 {
 	struct axon_ram_bank *bank = bio->bi_bdev->bd_disk->private_data;
@@ -113,7 +113,6 @@
 	struct bio_vec *vec;
 	unsigned int transfered;
 	unsigned short idx;
-	int rc = 0;
 
 	phys_mem = bank->io_addr + (bio->bi_sector << AXON_RAM_SECTOR_SHIFT);
 	phys_end = bank->io_addr + bank->size;
@@ -121,8 +120,7 @@
 	bio_for_each_segment(vec, bio, idx) {
 		if (unlikely(phys_mem + vec->bv_len > phys_end)) {
 			bio_io_error(bio);
-			rc = -ERANGE;
-			break;
+			return;
 		}
 
 		user_mem = page_address(vec->bv_page) + vec->bv_offset;
@@ -135,8 +133,6 @@
 		transfered += vec->bv_len;
 	}
 	bio_endio(bio, 0);
-
-	return rc;
 }
 
 /**
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index b596e54..d61ec56 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -768,25 +768,14 @@
 	return disk_total;
 }
 
-static int blkio_check_dev_num(dev_t dev)
-{
-	int part = 0;
-	struct gendisk *disk;
-
-	disk = get_gendisk(dev, &part);
-	if (!disk || part)
-		return -ENODEV;
-
-	return 0;
-}
-
 static int blkio_policy_parse_and_set(char *buf,
 	struct blkio_policy_node *newpn, enum blkio_policy_id plid, int fileid)
 {
+	struct gendisk *disk = NULL;
 	char *s[4], *p, *major_s = NULL, *minor_s = NULL;
-	int ret;
 	unsigned long major, minor;
-	int i = 0;
+	int i = 0, ret = -EINVAL;
+	int part;
 	dev_t dev;
 	u64 temp;
 
@@ -804,37 +793,36 @@
 	}
 
 	if (i != 2)
-		return -EINVAL;
+		goto out;
 
 	p = strsep(&s[0], ":");
 	if (p != NULL)
 		major_s = p;
 	else
-		return -EINVAL;
+		goto out;
 
 	minor_s = s[0];
 	if (!minor_s)
-		return -EINVAL;
+		goto out;
 
-	ret = strict_strtoul(major_s, 10, &major);
-	if (ret)
-		return -EINVAL;
+	if (strict_strtoul(major_s, 10, &major))
+		goto out;
 
-	ret = strict_strtoul(minor_s, 10, &minor);
-	if (ret)
-		return -EINVAL;
+	if (strict_strtoul(minor_s, 10, &minor))
+		goto out;
 
 	dev = MKDEV(major, minor);
 
-	ret = strict_strtoull(s[1], 10, &temp);
-	if (ret)
-		return -EINVAL;
+	if (strict_strtoull(s[1], 10, &temp))
+		goto out;
 
 	/* For rule removal, do not check for device presence. */
 	if (temp) {
-		ret = blkio_check_dev_num(dev);
-		if (ret)
-			return ret;
+		disk = get_gendisk(dev, &part);
+		if (!disk || part) {
+			ret = -ENODEV;
+			goto out;
+		}
 	}
 
 	newpn->dev = dev;
@@ -843,7 +831,7 @@
 	case BLKIO_POLICY_PROP:
 		if ((temp < BLKIO_WEIGHT_MIN && temp > 0) ||
 		     temp > BLKIO_WEIGHT_MAX)
-			return -EINVAL;
+			goto out;
 
 		newpn->plid = plid;
 		newpn->fileid = fileid;
@@ -860,7 +848,7 @@
 		case BLKIO_THROTL_read_iops_device:
 		case BLKIO_THROTL_write_iops_device:
 			if (temp > THROTL_IOPS_MAX)
-				return -EINVAL;
+				goto out;
 
 			newpn->plid = plid;
 			newpn->fileid = fileid;
@@ -871,8 +859,10 @@
 	default:
 		BUG();
 	}
-
-	return 0;
+	ret = 0;
+out:
+	put_disk(disk);
+	return ret;
 }
 
 unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg,
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index a71d290..6f3ace7 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -188,7 +188,7 @@
 	union {
 		unsigned int weight;
 		/*
-		 * Rate read/write in terms of byptes per second
+		 * Rate read/write in terms of bytes per second
 		 * Whether this rate represents read or write is determined
 		 * by file type "fileid".
 		 */
diff --git a/block/blk-core.c b/block/blk-core.c
index 795154e..f658711 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -28,6 +28,7 @@
 #include <linux/task_io_accounting_ops.h>
 #include <linux/fault-inject.h>
 #include <linux/list_sort.h>
+#include <linux/delay.h>
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/block.h>
@@ -38,8 +39,6 @@
 EXPORT_TRACEPOINT_SYMBOL_GPL(block_rq_remap);
 EXPORT_TRACEPOINT_SYMBOL_GPL(block_bio_complete);
 
-static int __make_request(struct request_queue *q, struct bio *bio);
-
 /*
  * For the allocated request tables
  */
@@ -347,30 +346,75 @@
 }
 EXPORT_SYMBOL(blk_put_queue);
 
-/*
- * Note: If a driver supplied the queue lock, it is disconnected
- * by this function. The actual state of the lock doesn't matter
- * here as the request_queue isn't accessible after this point
- * (QUEUE_FLAG_DEAD is set) and no other requests will be queued.
+/**
+ * blk_drain_queue - drain requests from request_queue
+ * @q: queue to drain
+ * @drain_all: whether to drain all requests or only the ones w/ ELVPRIV
+ *
+ * Drain requests from @q.  If @drain_all is set, all requests are drained.
+ * If not, only ELVPRIV requests are drained.  The caller is responsible
+ * for ensuring that no new requests which need to be drained are queued.
+ */
+void blk_drain_queue(struct request_queue *q, bool drain_all)
+{
+	while (true) {
+		int nr_rqs;
+
+		spin_lock_irq(q->queue_lock);
+
+		elv_drain_elevator(q);
+		if (drain_all)
+			blk_throtl_drain(q);
+
+		__blk_run_queue(q);
+
+		if (drain_all)
+			nr_rqs = q->rq.count[0] + q->rq.count[1];
+		else
+			nr_rqs = q->rq.elvpriv;
+
+		spin_unlock_irq(q->queue_lock);
+
+		if (!nr_rqs)
+			break;
+		msleep(10);
+	}
+}
+
+/**
+ * blk_cleanup_queue - shutdown a request queue
+ * @q: request queue to shutdown
+ *
+ * Mark @q DEAD, drain all pending requests, destroy and put it.  All
+ * future requests will be failed immediately with -ENODEV.
  */
 void blk_cleanup_queue(struct request_queue *q)
 {
-	/*
-	 * We know we have process context here, so we can be a little
-	 * cautious and ensure that pending block actions on this device
-	 * are done before moving on. Going into this function, we should
-	 * not have processes doing IO to this device.
-	 */
-	blk_sync_queue(q);
+	spinlock_t *lock = q->queue_lock;
 
-	del_timer_sync(&q->backing_dev_info.laptop_mode_wb_timer);
+	/* mark @q DEAD, no new request or merges will be allowed afterwards */
 	mutex_lock(&q->sysfs_lock);
 	queue_flag_set_unlocked(QUEUE_FLAG_DEAD, q);
-	mutex_unlock(&q->sysfs_lock);
+
+	spin_lock_irq(lock);
+	queue_flag_set(QUEUE_FLAG_NOMERGES, q);
+	queue_flag_set(QUEUE_FLAG_NOXMERGES, q);
+	queue_flag_set(QUEUE_FLAG_DEAD, q);
 
 	if (q->queue_lock != &q->__queue_lock)
 		q->queue_lock = &q->__queue_lock;
 
+	spin_unlock_irq(lock);
+	mutex_unlock(&q->sysfs_lock);
+
+	/* drain all requests queued before DEAD marking */
+	blk_drain_queue(q, true);
+
+	/* @q won't process any more request, flush async actions */
+	del_timer_sync(&q->backing_dev_info.laptop_mode_wb_timer);
+	blk_sync_queue(q);
+
+	/* @q is and will stay empty, shutdown and put */
 	blk_put_queue(q);
 }
 EXPORT_SYMBOL(blk_cleanup_queue);
@@ -541,7 +585,7 @@
 	/*
 	 * This also sets hw/phys segments, boundary and size
 	 */
-	blk_queue_make_request(q, __make_request);
+	blk_queue_make_request(q, blk_queue_bio);
 
 	q->sg_reserved_size = INT_MAX;
 
@@ -576,7 +620,7 @@
 }
 
 static struct request *
-blk_alloc_request(struct request_queue *q, int flags, int priv, gfp_t gfp_mask)
+blk_alloc_request(struct request_queue *q, unsigned int flags, gfp_t gfp_mask)
 {
 	struct request *rq = mempool_alloc(q->rq.rq_pool, gfp_mask);
 
@@ -587,12 +631,10 @@
 
 	rq->cmd_flags = flags | REQ_ALLOCED;
 
-	if (priv) {
-		if (unlikely(elv_set_request(q, rq, gfp_mask))) {
-			mempool_free(rq, q->rq.rq_pool);
-			return NULL;
-		}
-		rq->cmd_flags |= REQ_ELVPRIV;
+	if ((flags & REQ_ELVPRIV) &&
+	    unlikely(elv_set_request(q, rq, gfp_mask))) {
+		mempool_free(rq, q->rq.rq_pool);
+		return NULL;
 	}
 
 	return rq;
@@ -651,12 +693,13 @@
  * A request has just been released.  Account for it, update the full and
  * congestion status, wake up any waiters.   Called under q->queue_lock.
  */
-static void freed_request(struct request_queue *q, int sync, int priv)
+static void freed_request(struct request_queue *q, unsigned int flags)
 {
 	struct request_list *rl = &q->rq;
+	int sync = rw_is_sync(flags);
 
 	rl->count[sync]--;
-	if (priv)
+	if (flags & REQ_ELVPRIV)
 		rl->elvpriv--;
 
 	__freed_request(q, sync);
@@ -684,10 +727,19 @@
 	return true;
 }
 
-/*
- * Get a free request, queue_lock must be held.
- * Returns NULL on failure, with queue_lock held.
- * Returns !NULL on success, with queue_lock *not held*.
+/**
+ * get_request - get a free request
+ * @q: request_queue to allocate request from
+ * @rw_flags: RW and SYNC flags
+ * @bio: bio to allocate request for (can be %NULL)
+ * @gfp_mask: allocation mask
+ *
+ * Get a free request from @q.  This function may fail under memory
+ * pressure or if @q is dead.
+ *
+ * Must be callled with @q->queue_lock held and,
+ * Returns %NULL on failure, with @q->queue_lock held.
+ * Returns !%NULL on success, with @q->queue_lock *not held*.
  */
 static struct request *get_request(struct request_queue *q, int rw_flags,
 				   struct bio *bio, gfp_t gfp_mask)
@@ -696,7 +748,10 @@
 	struct request_list *rl = &q->rq;
 	struct io_context *ioc = NULL;
 	const bool is_sync = rw_is_sync(rw_flags) != 0;
-	int may_queue, priv = 0;
+	int may_queue;
+
+	if (unlikely(test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)))
+		return NULL;
 
 	may_queue = elv_may_queue(q, rw_flags);
 	if (may_queue == ELV_MQUEUE_NO)
@@ -740,17 +795,17 @@
 	rl->count[is_sync]++;
 	rl->starved[is_sync] = 0;
 
-	if (blk_rq_should_init_elevator(bio)) {
-		priv = !test_bit(QUEUE_FLAG_ELVSWITCH, &q->queue_flags);
-		if (priv)
-			rl->elvpriv++;
+	if (blk_rq_should_init_elevator(bio) &&
+	    !test_bit(QUEUE_FLAG_ELVSWITCH, &q->queue_flags)) {
+		rw_flags |= REQ_ELVPRIV;
+		rl->elvpriv++;
 	}
 
 	if (blk_queue_io_stat(q))
 		rw_flags |= REQ_IO_STAT;
 	spin_unlock_irq(q->queue_lock);
 
-	rq = blk_alloc_request(q, rw_flags, priv, gfp_mask);
+	rq = blk_alloc_request(q, rw_flags, gfp_mask);
 	if (unlikely(!rq)) {
 		/*
 		 * Allocation failed presumably due to memory. Undo anything
@@ -760,7 +815,7 @@
 		 * wait queue, but this is pretty rare.
 		 */
 		spin_lock_irq(q->queue_lock);
-		freed_request(q, is_sync, priv);
+		freed_request(q, rw_flags);
 
 		/*
 		 * in the very unlikely event that allocation failed and no
@@ -790,11 +845,18 @@
 	return rq;
 }
 
-/*
- * No available requests for this queue, wait for some requests to become
- * available.
+/**
+ * get_request_wait - get a free request with retry
+ * @q: request_queue to allocate request from
+ * @rw_flags: RW and SYNC flags
+ * @bio: bio to allocate request for (can be %NULL)
  *
- * Called with q->queue_lock held, and returns with it unlocked.
+ * Get a free request from @q.  This function keeps retrying under memory
+ * pressure and fails iff @q is dead.
+ *
+ * Must be callled with @q->queue_lock held and,
+ * Returns %NULL on failure, with @q->queue_lock held.
+ * Returns !%NULL on success, with @q->queue_lock *not held*.
  */
 static struct request *get_request_wait(struct request_queue *q, int rw_flags,
 					struct bio *bio)
@@ -808,6 +870,9 @@
 		struct io_context *ioc;
 		struct request_list *rl = &q->rq;
 
+		if (unlikely(test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)))
+			return NULL;
+
 		prepare_to_wait_exclusive(&rl->wait[is_sync], &wait,
 				TASK_UNINTERRUPTIBLE);
 
@@ -838,19 +903,15 @@
 {
 	struct request *rq;
 
-	if (unlikely(test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)))
-		return NULL;
-
 	BUG_ON(rw != READ && rw != WRITE);
 
 	spin_lock_irq(q->queue_lock);
-	if (gfp_mask & __GFP_WAIT) {
+	if (gfp_mask & __GFP_WAIT)
 		rq = get_request_wait(q, rw, NULL);
-	} else {
+	else
 		rq = get_request(q, rw, NULL, gfp_mask);
-		if (!rq)
-			spin_unlock_irq(q->queue_lock);
-	}
+	if (!rq)
+		spin_unlock_irq(q->queue_lock);
 	/* q->queue_lock is unlocked at this point */
 
 	return rq;
@@ -1052,14 +1113,13 @@
 	 * it didn't come out of our reserved rq pools
 	 */
 	if (req->cmd_flags & REQ_ALLOCED) {
-		int is_sync = rq_is_sync(req) != 0;
-		int priv = req->cmd_flags & REQ_ELVPRIV;
+		unsigned int flags = req->cmd_flags;
 
 		BUG_ON(!list_empty(&req->queuelist));
 		BUG_ON(!hlist_unhashed(&req->hash));
 
 		blk_free_request(q, req);
-		freed_request(q, is_sync, priv);
+		freed_request(q, flags);
 	}
 }
 EXPORT_SYMBOL_GPL(__blk_put_request);
@@ -1161,18 +1221,32 @@
 	return true;
 }
 
-/*
- * Attempts to merge with the plugged list in the current process. Returns
- * true if merge was successful, otherwise false.
+/**
+ * attempt_plug_merge - try to merge with %current's plugged list
+ * @q: request_queue new bio is being queued at
+ * @bio: new bio being queued
+ * @request_count: out parameter for number of traversed plugged requests
+ *
+ * Determine whether @bio being queued on @q can be merged with a request
+ * on %current's plugged list.  Returns %true if merge was successful,
+ * otherwise %false.
+ *
+ * This function is called without @q->queue_lock; however, elevator is
+ * accessed iff there already are requests on the plugged list which in
+ * turn guarantees validity of the elevator.
+ *
+ * Note that, on successful merge, elevator operation
+ * elevator_bio_merged_fn() will be called without queue lock.  Elevator
+ * must be ready for this.
  */
-static bool attempt_plug_merge(struct task_struct *tsk, struct request_queue *q,
-			       struct bio *bio, unsigned int *request_count)
+static bool attempt_plug_merge(struct request_queue *q, struct bio *bio,
+			       unsigned int *request_count)
 {
 	struct blk_plug *plug;
 	struct request *rq;
 	bool ret = false;
 
-	plug = tsk->plug;
+	plug = current->plug;
 	if (!plug)
 		goto out;
 	*request_count = 0;
@@ -1202,7 +1276,6 @@
 
 void init_request_from_bio(struct request *req, struct bio *bio)
 {
-	req->cpu = bio->bi_comp_cpu;
 	req->cmd_type = REQ_TYPE_FS;
 
 	req->cmd_flags |= bio->bi_rw & REQ_COMMON_MASK;
@@ -1215,7 +1288,7 @@
 	blk_rq_bio_prep(req->q, req, bio);
 }
 
-static int __make_request(struct request_queue *q, struct bio *bio)
+void blk_queue_bio(struct request_queue *q, struct bio *bio)
 {
 	const bool sync = !!(bio->bi_rw & REQ_SYNC);
 	struct blk_plug *plug;
@@ -1240,8 +1313,8 @@
 	 * Check if we can merge with the plugged list before grabbing
 	 * any locks.
 	 */
-	if (attempt_plug_merge(current, q, bio, &request_count))
-		goto out;
+	if (attempt_plug_merge(q, bio, &request_count))
+		return;
 
 	spin_lock_irq(q->queue_lock);
 
@@ -1275,6 +1348,10 @@
 	 * Returns with the queue unlocked.
 	 */
 	req = get_request_wait(q, rw_flags, bio);
+	if (unlikely(!req)) {
+		bio_endio(bio, -ENODEV);	/* @q is dead */
+		goto out_unlock;
+	}
 
 	/*
 	 * After dropping the lock and possibly sleeping here, our request
@@ -1284,8 +1361,7 @@
 	 */
 	init_request_from_bio(req, bio);
 
-	if (test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags) ||
-	    bio_flagged(bio, BIO_CPU_AFFINE))
+	if (test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags))
 		req->cpu = raw_smp_processor_id();
 
 	plug = current->plug;
@@ -1316,9 +1392,8 @@
 out_unlock:
 		spin_unlock_irq(q->queue_lock);
 	}
-out:
-	return 0;
 }
+EXPORT_SYMBOL_GPL(blk_queue_bio);	/* for device mapper only */
 
 /*
  * If bio->bi_dev is a partition, remap the location
@@ -1417,6 +1492,89 @@
 	return 0;
 }
 
+static noinline_for_stack bool
+generic_make_request_checks(struct bio *bio)
+{
+	struct request_queue *q;
+	int nr_sectors = bio_sectors(bio);
+	int err = -EIO;
+	char b[BDEVNAME_SIZE];
+	struct hd_struct *part;
+
+	might_sleep();
+
+	if (bio_check_eod(bio, nr_sectors))
+		goto end_io;
+
+	q = bdev_get_queue(bio->bi_bdev);
+	if (unlikely(!q)) {
+		printk(KERN_ERR
+		       "generic_make_request: Trying to access "
+			"nonexistent block-device %s (%Lu)\n",
+			bdevname(bio->bi_bdev, b),
+			(long long) bio->bi_sector);
+		goto end_io;
+	}
+
+	if (unlikely(!(bio->bi_rw & REQ_DISCARD) &&
+		     nr_sectors > queue_max_hw_sectors(q))) {
+		printk(KERN_ERR "bio too big device %s (%u > %u)\n",
+		       bdevname(bio->bi_bdev, b),
+		       bio_sectors(bio),
+		       queue_max_hw_sectors(q));
+		goto end_io;
+	}
+
+	part = bio->bi_bdev->bd_part;
+	if (should_fail_request(part, bio->bi_size) ||
+	    should_fail_request(&part_to_disk(part)->part0,
+				bio->bi_size))
+		goto end_io;
+
+	/*
+	 * If this device has partitions, remap block n
+	 * of partition p to block n+start(p) of the disk.
+	 */
+	blk_partition_remap(bio);
+
+	if (bio_integrity_enabled(bio) && bio_integrity_prep(bio))
+		goto end_io;
+
+	if (bio_check_eod(bio, nr_sectors))
+		goto end_io;
+
+	/*
+	 * Filter flush bio's early so that make_request based
+	 * drivers without flush support don't have to worry
+	 * about them.
+	 */
+	if ((bio->bi_rw & (REQ_FLUSH | REQ_FUA)) && !q->flush_flags) {
+		bio->bi_rw &= ~(REQ_FLUSH | REQ_FUA);
+		if (!nr_sectors) {
+			err = 0;
+			goto end_io;
+		}
+	}
+
+	if ((bio->bi_rw & REQ_DISCARD) &&
+	    (!blk_queue_discard(q) ||
+	     ((bio->bi_rw & REQ_SECURE) &&
+	      !blk_queue_secdiscard(q)))) {
+		err = -EOPNOTSUPP;
+		goto end_io;
+	}
+
+	if (blk_throtl_bio(q, bio))
+		return false;	/* throttled, will be resubmitted later */
+
+	trace_block_bio_queue(q, bio);
+	return true;
+
+end_io:
+	bio_endio(bio, err);
+	return false;
+}
+
 /**
  * generic_make_request - hand a buffer to its device driver for I/O
  * @bio:  The bio describing the location in memory and on the device.
@@ -1437,145 +1595,32 @@
  * completion notification should be signaled.
  *
  * generic_make_request and the drivers it calls may use bi_next if this
- * bio happens to be merged with someone else, and may change bi_dev and
- * bi_sector for remaps as it sees fit.  So the values of these fields
- * should NOT be depended on after the call to generic_make_request.
- */
-static inline void __generic_make_request(struct bio *bio)
-{
-	struct request_queue *q;
-	sector_t old_sector;
-	int ret, nr_sectors = bio_sectors(bio);
-	dev_t old_dev;
-	int err = -EIO;
-
-	might_sleep();
-
-	if (bio_check_eod(bio, nr_sectors))
-		goto end_io;
-
-	/*
-	 * Resolve the mapping until finished. (drivers are
-	 * still free to implement/resolve their own stacking
-	 * by explicitly returning 0)
-	 *
-	 * NOTE: we don't repeat the blk_size check for each new device.
-	 * Stacking drivers are expected to know what they are doing.
-	 */
-	old_sector = -1;
-	old_dev = 0;
-	do {
-		char b[BDEVNAME_SIZE];
-		struct hd_struct *part;
-
-		q = bdev_get_queue(bio->bi_bdev);
-		if (unlikely(!q)) {
-			printk(KERN_ERR
-			       "generic_make_request: Trying to access "
-				"nonexistent block-device %s (%Lu)\n",
-				bdevname(bio->bi_bdev, b),
-				(long long) bio->bi_sector);
-			goto end_io;
-		}
-
-		if (unlikely(!(bio->bi_rw & REQ_DISCARD) &&
-			     nr_sectors > queue_max_hw_sectors(q))) {
-			printk(KERN_ERR "bio too big device %s (%u > %u)\n",
-			       bdevname(bio->bi_bdev, b),
-			       bio_sectors(bio),
-			       queue_max_hw_sectors(q));
-			goto end_io;
-		}
-
-		if (unlikely(test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)))
-			goto end_io;
-
-		part = bio->bi_bdev->bd_part;
-		if (should_fail_request(part, bio->bi_size) ||
-		    should_fail_request(&part_to_disk(part)->part0,
-					bio->bi_size))
-			goto end_io;
-
-		/*
-		 * If this device has partitions, remap block n
-		 * of partition p to block n+start(p) of the disk.
-		 */
-		blk_partition_remap(bio);
-
-		if (bio_integrity_enabled(bio) && bio_integrity_prep(bio))
-			goto end_io;
-
-		if (old_sector != -1)
-			trace_block_bio_remap(q, bio, old_dev, old_sector);
-
-		old_sector = bio->bi_sector;
-		old_dev = bio->bi_bdev->bd_dev;
-
-		if (bio_check_eod(bio, nr_sectors))
-			goto end_io;
-
-		/*
-		 * Filter flush bio's early so that make_request based
-		 * drivers without flush support don't have to worry
-		 * about them.
-		 */
-		if ((bio->bi_rw & (REQ_FLUSH | REQ_FUA)) && !q->flush_flags) {
-			bio->bi_rw &= ~(REQ_FLUSH | REQ_FUA);
-			if (!nr_sectors) {
-				err = 0;
-				goto end_io;
-			}
-		}
-
-		if ((bio->bi_rw & REQ_DISCARD) &&
-		    (!blk_queue_discard(q) ||
-		     ((bio->bi_rw & REQ_SECURE) &&
-		      !blk_queue_secdiscard(q)))) {
-			err = -EOPNOTSUPP;
-			goto end_io;
-		}
-
-		if (blk_throtl_bio(q, &bio))
-			goto end_io;
-
-		/*
-		 * If bio = NULL, bio has been throttled and will be submitted
-		 * later.
-		 */
-		if (!bio)
-			break;
-
-		trace_block_bio_queue(q, bio);
-
-		ret = q->make_request_fn(q, bio);
-	} while (ret);
-
-	return;
-
-end_io:
-	bio_endio(bio, err);
-}
-
-/*
- * We only want one ->make_request_fn to be active at a time,
- * else stack usage with stacked devices could be a problem.
- * So use current->bio_list to keep a list of requests
- * submited by a make_request_fn function.
- * current->bio_list is also used as a flag to say if
- * generic_make_request is currently active in this task or not.
- * If it is NULL, then no make_request is active.  If it is non-NULL,
- * then a make_request is active, and new requests should be added
- * at the tail
+ * bio happens to be merged with someone else, and may resubmit the bio to
+ * a lower device by calling into generic_make_request recursively, which
+ * means the bio should NOT be touched after the call to ->make_request_fn.
  */
 void generic_make_request(struct bio *bio)
 {
 	struct bio_list bio_list_on_stack;
 
+	if (!generic_make_request_checks(bio))
+		return;
+
+	/*
+	 * We only want one ->make_request_fn to be active at a time, else
+	 * stack usage with stacked devices could be a problem.  So use
+	 * current->bio_list to keep a list of requests submited by a
+	 * make_request_fn function.  current->bio_list is also used as a
+	 * flag to say if generic_make_request is currently active in this
+	 * task or not.  If it is NULL, then no make_request is active.  If
+	 * it is non-NULL, then a make_request is active, and new requests
+	 * should be added at the tail
+	 */
 	if (current->bio_list) {
-		/* make_request is active */
 		bio_list_add(current->bio_list, bio);
 		return;
 	}
+
 	/* following loop may be a bit non-obvious, and so deserves some
 	 * explanation.
 	 * Before entering the loop, bio->bi_next is NULL (as all callers
@@ -1583,22 +1628,21 @@
 	 * We pretend that we have just taken it off a longer list, so
 	 * we assign bio_list to a pointer to the bio_list_on_stack,
 	 * thus initialising the bio_list of new bios to be
-	 * added.  __generic_make_request may indeed add some more bios
+	 * added.  ->make_request() may indeed add some more bios
 	 * through a recursive call to generic_make_request.  If it
 	 * did, we find a non-NULL value in bio_list and re-enter the loop
 	 * from the top.  In this case we really did just take the bio
 	 * of the top of the list (no pretending) and so remove it from
-	 * bio_list, and call into __generic_make_request again.
-	 *
-	 * The loop was structured like this to make only one call to
-	 * __generic_make_request (which is important as it is large and
-	 * inlined) and to keep the structure simple.
+	 * bio_list, and call into ->make_request() again.
 	 */
 	BUG_ON(bio->bi_next);
 	bio_list_init(&bio_list_on_stack);
 	current->bio_list = &bio_list_on_stack;
 	do {
-		__generic_make_request(bio);
+		struct request_queue *q = bdev_get_queue(bio->bi_bdev);
+
+		q->make_request_fn(q, bio);
+
 		bio = bio_list_pop(current->bio_list);
 	} while (bio);
 	current->bio_list = NULL; /* deactivate */
@@ -2630,6 +2674,20 @@
 
 #define PLUG_MAGIC	0x91827364
 
+/**
+ * blk_start_plug - initialize blk_plug and track it inside the task_struct
+ * @plug:	The &struct blk_plug that needs to be initialized
+ *
+ * Description:
+ *   Tracking blk_plug inside the task_struct will help with auto-flushing the
+ *   pending I/O should the task end up blocking between blk_start_plug() and
+ *   blk_finish_plug(). This is important from a performance perspective, but
+ *   also ensures that we don't deadlock. For instance, if the task is blocking
+ *   for a memory allocation, memory reclaim could end up wanting to free a
+ *   page belonging to that request that is currently residing in our private
+ *   plug. By flushing the pending I/O when the process goes to sleep, we avoid
+ *   this kind of deadlock.
+ */
 void blk_start_plug(struct blk_plug *plug)
 {
 	struct task_struct *tsk = current;
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 60fda88..e7f9f65 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -457,11 +457,11 @@
 }
 
 /**
- * blk_cleanup_queue: - release a &struct request_queue when it is no longer needed
- * @kobj:    the kobj belonging of the request queue to be released
+ * blk_release_queue: - release a &struct request_queue when it is no longer needed
+ * @kobj:    the kobj belonging to the request queue to be released
  *
  * Description:
- *     blk_cleanup_queue is the pair to blk_init_queue() or
+ *     blk_release_queue is the pair to blk_init_queue() or
  *     blk_queue_make_request().  It should be called when a request queue is
  *     being released; typically when a block device is being de-registered.
  *     Currently, its primary task it to free all the &struct request
@@ -490,6 +490,7 @@
 	if (q->queue_tags)
 		__blk_queue_free_tags(q);
 
+	blk_throtl_release(q);
 	blk_trace_shutdown(q);
 
 	bdi_destroy(&q->backing_dev_info);
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index a19f58c..8edb949 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -10,6 +10,7 @@
 #include <linux/bio.h>
 #include <linux/blktrace_api.h>
 #include "blk-cgroup.h"
+#include "blk.h"
 
 /* Max dispatch from a group in 1 round */
 static int throtl_grp_quantum = 8;
@@ -302,16 +303,16 @@
 	return tg;
 }
 
-/*
- * This function returns with queue lock unlocked in case of error, like
- * request queue is no more
- */
 static struct throtl_grp * throtl_get_tg(struct throtl_data *td)
 {
 	struct throtl_grp *tg = NULL, *__tg = NULL;
 	struct blkio_cgroup *blkcg;
 	struct request_queue *q = td->queue;
 
+	/* no throttling for dead queue */
+	if (unlikely(test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)))
+		return NULL;
+
 	rcu_read_lock();
 	blkcg = task_blkio_cgroup(current);
 	tg = throtl_find_tg(td, blkcg);
@@ -323,32 +324,22 @@
 	/*
 	 * Need to allocate a group. Allocation of group also needs allocation
 	 * of per cpu stats which in-turn takes a mutex() and can block. Hence
-	 * we need to drop rcu lock and queue_lock before we call alloc
-	 *
-	 * Take the request queue reference to make sure queue does not
-	 * go away once we return from allocation.
+	 * we need to drop rcu lock and queue_lock before we call alloc.
 	 */
-	blk_get_queue(q);
 	rcu_read_unlock();
 	spin_unlock_irq(q->queue_lock);
 
 	tg = throtl_alloc_tg(td);
-	/*
-	 * We might have slept in group allocation. Make sure queue is not
-	 * dead
-	 */
-	if (unlikely(test_bit(QUEUE_FLAG_DEAD, &q->queue_flags))) {
-		blk_put_queue(q);
-		if (tg)
-			kfree(tg);
-
-		return ERR_PTR(-ENODEV);
-	}
-	blk_put_queue(q);
 
 	/* Group allocated and queue is still alive. take the lock */
 	spin_lock_irq(q->queue_lock);
 
+	/* Make sure @q is still alive */
+	if (unlikely(test_bit(QUEUE_FLAG_DEAD, &q->queue_flags))) {
+		kfree(tg);
+		return NULL;
+	}
+
 	/*
 	 * Initialize the new group. After sleeping, read the blkcg again.
 	 */
@@ -1014,11 +1005,6 @@
 	}
 }
 
-static void throtl_td_free(struct throtl_data *td)
-{
-	kfree(td);
-}
-
 /*
  * Blk cgroup controller notification saying that blkio_group object is being
  * delinked as associated cgroup object is going away. That also means that
@@ -1123,17 +1109,17 @@
 	.plid = BLKIO_POLICY_THROTL,
 };
 
-int blk_throtl_bio(struct request_queue *q, struct bio **biop)
+bool blk_throtl_bio(struct request_queue *q, struct bio *bio)
 {
 	struct throtl_data *td = q->td;
 	struct throtl_grp *tg;
-	struct bio *bio = *biop;
 	bool rw = bio_data_dir(bio), update_disptime = true;
 	struct blkio_cgroup *blkcg;
+	bool throttled = false;
 
 	if (bio->bi_rw & REQ_THROTTLED) {
 		bio->bi_rw &= ~REQ_THROTTLED;
-		return 0;
+		goto out;
 	}
 
 	/*
@@ -1152,7 +1138,7 @@
 			blkiocg_update_dispatch_stats(&tg->blkg, bio->bi_size,
 					rw, rw_is_sync(bio->bi_rw));
 			rcu_read_unlock();
-			return 0;
+			goto out;
 		}
 	}
 	rcu_read_unlock();
@@ -1161,18 +1147,10 @@
 	 * Either group has not been allocated yet or it is not an unlimited
 	 * IO group
 	 */
-
 	spin_lock_irq(q->queue_lock);
 	tg = throtl_get_tg(td);
-
-	if (IS_ERR(tg)) {
-		if (PTR_ERR(tg)	== -ENODEV) {
-			/*
-			 * Queue is gone. No queue lock held here.
-			 */
-			return -ENODEV;
-		}
-	}
+	if (unlikely(!tg))
+		goto out_unlock;
 
 	if (tg->nr_queued[rw]) {
 		/*
@@ -1200,7 +1178,7 @@
 		 * So keep on trimming slice even if bio is not queued.
 		 */
 		throtl_trim_slice(td, tg, rw);
-		goto out;
+		goto out_unlock;
 	}
 
 queue_bio:
@@ -1212,16 +1190,52 @@
 			tg->nr_queued[READ], tg->nr_queued[WRITE]);
 
 	throtl_add_bio_tg(q->td, tg, bio);
-	*biop = NULL;
+	throttled = true;
 
 	if (update_disptime) {
 		tg_update_disptime(td, tg);
 		throtl_schedule_next_dispatch(td);
 	}
 
-out:
+out_unlock:
 	spin_unlock_irq(q->queue_lock);
-	return 0;
+out:
+	return throttled;
+}
+
+/**
+ * blk_throtl_drain - drain throttled bios
+ * @q: request_queue to drain throttled bios for
+ *
+ * Dispatch all currently throttled bios on @q through ->make_request_fn().
+ */
+void blk_throtl_drain(struct request_queue *q)
+	__releases(q->queue_lock) __acquires(q->queue_lock)
+{
+	struct throtl_data *td = q->td;
+	struct throtl_rb_root *st = &td->tg_service_tree;
+	struct throtl_grp *tg;
+	struct bio_list bl;
+	struct bio *bio;
+
+	lockdep_is_held(q->queue_lock);
+
+	bio_list_init(&bl);
+
+	while ((tg = throtl_rb_first(st))) {
+		throtl_dequeue_tg(td, tg);
+
+		while ((bio = bio_list_peek(&tg->bio_lists[READ])))
+			tg_dispatch_one_bio(td, tg, bio_data_dir(bio), &bl);
+		while ((bio = bio_list_peek(&tg->bio_lists[WRITE])))
+			tg_dispatch_one_bio(td, tg, bio_data_dir(bio), &bl);
+	}
+	spin_unlock_irq(q->queue_lock);
+
+	while ((bio = bio_list_pop(&bl)))
+		generic_make_request(bio);
+
+	spin_lock_irq(q->queue_lock);
 }
 
 int blk_throtl_init(struct request_queue *q)
@@ -1296,7 +1310,11 @@
 	 * it.
 	 */
 	throtl_shutdown_wq(q);
-	throtl_td_free(td);
+}
+
+void blk_throtl_release(struct request_queue *q)
+{
+	kfree(q->td);
 }
 
 static int __init throtl_init(void)
diff --git a/block/blk.h b/block/blk.h
index 20b900a..3f6551b 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -15,6 +15,7 @@
 			struct bio *bio);
 int blk_rq_append_bio(struct request_queue *q, struct request *rq,
 		      struct bio *bio);
+void blk_drain_queue(struct request_queue *q, bool drain_all);
 void blk_dequeue_request(struct request *rq);
 void __blk_queue_free_tags(struct request_queue *q);
 bool __blk_end_bidi_request(struct request *rq, int error,
@@ -188,4 +189,21 @@
 	        (rq->cmd_flags & REQ_DISCARD));
 }
 
-#endif
+#ifdef CONFIG_BLK_DEV_THROTTLING
+extern bool blk_throtl_bio(struct request_queue *q, struct bio *bio);
+extern void blk_throtl_drain(struct request_queue *q);
+extern int blk_throtl_init(struct request_queue *q);
+extern void blk_throtl_exit(struct request_queue *q);
+extern void blk_throtl_release(struct request_queue *q);
+#else /* CONFIG_BLK_DEV_THROTTLING */
+static inline bool blk_throtl_bio(struct request_queue *q, struct bio *bio)
+{
+	return false;
+}
+static inline void blk_throtl_drain(struct request_queue *q) { }
+static inline int blk_throtl_init(struct request_queue *q) { return 0; }
+static inline void blk_throtl_exit(struct request_queue *q) { }
+static inline void blk_throtl_release(struct request_queue *q) { }
+#endif /* CONFIG_BLK_DEV_THROTTLING */
+
+#endif /* BLK_INTERNAL_H */
diff --git a/block/elevator.c b/block/elevator.c
index a3b64bc..66343d6 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -31,7 +31,6 @@
 #include <linux/slab.h>
 #include <linux/init.h>
 #include <linux/compiler.h>
-#include <linux/delay.h>
 #include <linux/blktrace_api.h>
 #include <linux/hash.h>
 #include <linux/uaccess.h>
@@ -182,7 +181,7 @@
 	eq->elevator_data = data;
 }
 
-static char chosen_elevator[16];
+static char chosen_elevator[ELV_NAME_MAX];
 
 static int __init elevator_setup(char *str)
 {
@@ -606,43 +605,35 @@
 void elv_drain_elevator(struct request_queue *q)
 {
 	static int printed;
+
+	lockdep_assert_held(q->queue_lock);
+
 	while (q->elevator->ops->elevator_dispatch_fn(q, 1))
 		;
-	if (q->nr_sorted == 0)
-		return;
-	if (printed++ < 10) {
+	if (q->nr_sorted && printed++ < 10) {
 		printk(KERN_ERR "%s: forced dispatching is broken "
 		       "(nr_sorted=%u), please report this\n",
 		       q->elevator->elevator_type->elevator_name, q->nr_sorted);
 	}
 }
 
-/*
- * Call with queue lock held, interrupts disabled
- */
 void elv_quiesce_start(struct request_queue *q)
 {
 	if (!q->elevator)
 		return;
 
+	spin_lock_irq(q->queue_lock);
 	queue_flag_set(QUEUE_FLAG_ELVSWITCH, q);
+	spin_unlock_irq(q->queue_lock);
 
-	/*
-	 * make sure we don't have any requests in flight
-	 */
-	elv_drain_elevator(q);
-	while (q->rq.elvpriv) {
-		__blk_run_queue(q);
-		spin_unlock_irq(q->queue_lock);
-		msleep(10);
-		spin_lock_irq(q->queue_lock);
-		elv_drain_elevator(q);
-	}
+	blk_drain_queue(q, false);
 }
 
 void elv_quiesce_end(struct request_queue *q)
 {
+	spin_lock_irq(q->queue_lock);
 	queue_flag_clear(QUEUE_FLAG_ELVSWITCH, q);
+	spin_unlock_irq(q->queue_lock);
 }
 
 void __elv_add_request(struct request_queue *q, struct request *rq, int where)
@@ -972,7 +963,6 @@
 	/*
 	 * Turn on BYPASS and drain all requests w/ elevator private data
 	 */
-	spin_lock_irq(q->queue_lock);
 	elv_quiesce_start(q);
 
 	/*
@@ -983,8 +973,8 @@
 	/*
 	 * attach and start new elevator
 	 */
+	spin_lock_irq(q->queue_lock);
 	elevator_attach(q, e, data);
-
 	spin_unlock_irq(q->queue_lock);
 
 	if (old_elevator->registered) {
@@ -999,9 +989,7 @@
 	 * finally exit old elevator and turn off BYPASS.
 	 */
 	elevator_exit(old_elevator);
-	spin_lock_irq(q->queue_lock);
 	elv_quiesce_end(q);
-	spin_unlock_irq(q->queue_lock);
 
 	blk_add_trace_msg(q, "elv switch: %s", e->elevator_type->elevator_name);
 
@@ -1015,10 +1003,7 @@
 	elevator_exit(e);
 	q->elevator = old_elevator;
 	elv_register_queue(q);
-
-	spin_lock_irq(q->queue_lock);
-	queue_flag_clear(QUEUE_FLAG_ELVSWITCH, q);
-	spin_unlock_irq(q->queue_lock);
+	elv_quiesce_end(q);
 
 	return err;
 }
diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
index 4f4230b..fbdf0d8 100644
--- a/block/scsi_ioctl.c
+++ b/block/scsi_ioctl.c
@@ -565,7 +565,7 @@
 {
 	int err;
 
-	if (!q || blk_get_queue(q))
+	if (!q)
 		return -ENXIO;
 
 	switch (cmd) {
@@ -686,7 +686,6 @@
 			err = -ENOTTY;
 	}
 
-	blk_put_queue(q);
 	return err;
 }
 EXPORT_SYMBOL(scsi_cmd_ioctl);
diff --git a/drivers/block/aoe/aoeblk.c b/drivers/block/aoe/aoeblk.c
index 528f631..167ba0a 100644
--- a/drivers/block/aoe/aoeblk.c
+++ b/drivers/block/aoe/aoeblk.c
@@ -159,7 +159,7 @@
 	return 0;
 }
 
-static int
+static void
 aoeblk_make_request(struct request_queue *q, struct bio *bio)
 {
 	struct sk_buff_head queue;
@@ -172,25 +172,25 @@
 	if (bio == NULL) {
 		printk(KERN_ERR "aoe: bio is NULL\n");
 		BUG();
-		return 0;
+		return;
 	}
 	d = bio->bi_bdev->bd_disk->private_data;
 	if (d == NULL) {
 		printk(KERN_ERR "aoe: bd_disk->private_data is NULL\n");
 		BUG();
 		bio_endio(bio, -ENXIO);
-		return 0;
+		return;
 	} else if (bio->bi_io_vec == NULL) {
 		printk(KERN_ERR "aoe: bi_io_vec is NULL\n");
 		BUG();
 		bio_endio(bio, -ENXIO);
-		return 0;
+		return;
 	}
 	buf = mempool_alloc(d->bufpool, GFP_NOIO);
 	if (buf == NULL) {
 		printk(KERN_INFO "aoe: buf allocation failure\n");
 		bio_endio(bio, -ENOMEM);
-		return 0;
+		return;
 	}
 	memset(buf, 0, sizeof(*buf));
 	INIT_LIST_HEAD(&buf->bufs);
@@ -211,7 +211,7 @@
 		spin_unlock_irqrestore(&d->lock, flags);
 		mempool_free(buf, d->bufpool);
 		bio_endio(bio, -ENXIO);
-		return 0;
+		return;
 	}
 
 	list_add_tail(&buf->bufs, &d->bufq);
@@ -222,8 +222,6 @@
 
 	spin_unlock_irqrestore(&d->lock, flags);
 	aoenet_xmit(&queue);
-
-	return 0;
 }
 
 static int
diff --git a/drivers/block/brd.c b/drivers/block/brd.c
index dba1c32..d22119d 100644
--- a/drivers/block/brd.c
+++ b/drivers/block/brd.c
@@ -323,7 +323,7 @@
 	return err;
 }
 
-static int brd_make_request(struct request_queue *q, struct bio *bio)
+static void brd_make_request(struct request_queue *q, struct bio *bio)
 {
 	struct block_device *bdev = bio->bi_bdev;
 	struct brd_device *brd = bdev->bd_disk->private_data;
@@ -359,8 +359,6 @@
 
 out:
 	bio_endio(bio, err);
-
-	return 0;
 }
 
 #ifdef CONFIG_BLK_DEV_XIP
diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index ef2ceed..36eee39 100644
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -1507,7 +1507,7 @@
 extern int proc_details;
 
 /* drbd_req */
-extern int drbd_make_request(struct request_queue *q, struct bio *bio);
+extern void drbd_make_request(struct request_queue *q, struct bio *bio);
 extern int drbd_read_remote(struct drbd_conf *mdev, struct drbd_request *req);
 extern int drbd_merge_bvec(struct request_queue *q, struct bvec_merge_data *bvm, struct bio_vec *bvec);
 extern int is_valid_ar_handle(struct drbd_request *, sector_t);
diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c
index 3424d67..4a0f314 100644
--- a/drivers/block/drbd/drbd_req.c
+++ b/drivers/block/drbd/drbd_req.c
@@ -1073,7 +1073,7 @@
 	return 0;
 }
 
-int drbd_make_request(struct request_queue *q, struct bio *bio)
+void drbd_make_request(struct request_queue *q, struct bio *bio)
 {
 	unsigned int s_enr, e_enr;
 	struct drbd_conf *mdev = (struct drbd_conf *) q->queuedata;
@@ -1081,7 +1081,7 @@
 
 	if (drbd_fail_request_early(mdev, bio_data_dir(bio) & WRITE)) {
 		bio_endio(bio, -EPERM);
-		return 0;
+		return;
 	}
 
 	start_time = jiffies;
@@ -1100,7 +1100,8 @@
 
 	if (likely(s_enr == e_enr)) {
 		inc_ap_bio(mdev, 1);
-		return drbd_make_request_common(mdev, bio, start_time);
+		drbd_make_request_common(mdev, bio, start_time);
+		return;
 	}
 
 	/* can this bio be split generically?
@@ -1148,7 +1149,6 @@
 
 		bio_pair_release(bp);
 	}
-	return 0;
 }
 
 /* This is called by bio_add_page().  With this function we reduce
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 46cdd69..c77983e 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -437,7 +437,7 @@
 	return bio_list_pop(&lo->lo_bio_list);
 }
 
-static int loop_make_request(struct request_queue *q, struct bio *old_bio)
+static void loop_make_request(struct request_queue *q, struct bio *old_bio)
 {
 	struct loop_device *lo = q->queuedata;
 	int rw = bio_rw(old_bio);
@@ -455,12 +455,11 @@
 	loop_add_bio(lo, old_bio);
 	wake_up(&lo->lo_event);
 	spin_unlock_irq(&lo->lo_lock);
-	return 0;
+	return;
 
 out:
 	spin_unlock_irq(&lo->lo_lock);
 	bio_io_error(old_bio);
-	return 0;
 }
 
 struct switch_request {
diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index e133f09..a63b0a2 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -2444,7 +2444,7 @@
 	pkt_bio_finished(pd);
 }
 
-static int pkt_make_request(struct request_queue *q, struct bio *bio)
+static void pkt_make_request(struct request_queue *q, struct bio *bio)
 {
 	struct pktcdvd_device *pd;
 	char b[BDEVNAME_SIZE];
@@ -2473,7 +2473,7 @@
 		cloned_bio->bi_end_io = pkt_end_io_read_cloned;
 		pd->stats.secs_r += bio->bi_size >> 9;
 		pkt_queue_bio(pd, cloned_bio);
-		return 0;
+		return;
 	}
 
 	if (!test_bit(PACKET_WRITABLE, &pd->flags)) {
@@ -2509,7 +2509,7 @@
 			pkt_make_request(q, &bp->bio1);
 			pkt_make_request(q, &bp->bio2);
 			bio_pair_release(bp);
-			return 0;
+			return;
 		}
 	}
 
@@ -2533,7 +2533,7 @@
 				}
 				spin_unlock(&pkt->lock);
 				spin_unlock(&pd->cdrw.active_list_lock);
-				return 0;
+				return;
 			} else {
 				blocked_bio = 1;
 			}
@@ -2584,10 +2584,9 @@
 		 */
 		wake_up(&pd->wqueue);
 	}
-	return 0;
+	return;
 end_io:
 	bio_io_error(bio);
-	return 0;
 }
 
 
diff --git a/drivers/block/ps3vram.c b/drivers/block/ps3vram.c
index b3bdb8a..7fad7af 100644
--- a/drivers/block/ps3vram.c
+++ b/drivers/block/ps3vram.c
@@ -596,7 +596,7 @@
 	return next;
 }
 
-static int ps3vram_make_request(struct request_queue *q, struct bio *bio)
+static void ps3vram_make_request(struct request_queue *q, struct bio *bio)
 {
 	struct ps3_system_bus_device *dev = q->queuedata;
 	struct ps3vram_priv *priv = ps3_system_bus_get_drvdata(dev);
@@ -610,13 +610,11 @@
 	spin_unlock_irq(&priv->lock);
 
 	if (busy)
-		return 0;
+		return;
 
 	do {
 		bio = ps3vram_do_bio(dev, bio);
 	} while (bio);
-
-	return 0;
 }
 
 static int __devinit ps3vram_probe(struct ps3_system_bus_device *dev)
diff --git a/drivers/block/umem.c b/drivers/block/umem.c
index 031ca72..aa27120 100644
--- a/drivers/block/umem.c
+++ b/drivers/block/umem.c
@@ -513,7 +513,7 @@
 	}
 }
 
-static int mm_make_request(struct request_queue *q, struct bio *bio)
+static void mm_make_request(struct request_queue *q, struct bio *bio)
 {
 	struct cardinfo *card = q->queuedata;
 	pr_debug("mm_make_request %llu %u\n",
@@ -525,7 +525,7 @@
 	card->biotail = &bio->bi_next;
 	spin_unlock_irq(&card->lock);
 
-	return 0;
+	return;
 }
 
 static irqreturn_t mm_interrupt(int irq, void *__card)
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 52b39f3..7b986e7 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -180,9 +180,6 @@
 	/* forced geometry settings */
 	struct hd_geometry geometry;
 
-	/* For saving the address of __make_request for request based dm */
-	make_request_fn *saved_make_request_fn;
-
 	/* sysfs handle */
 	struct kobject kobj;
 
@@ -1391,7 +1388,7 @@
  * The request function that just remaps the bio built up by
  * dm_merge_bvec.
  */
-static int _dm_request(struct request_queue *q, struct bio *bio)
+static void _dm_request(struct request_queue *q, struct bio *bio)
 {
 	int rw = bio_data_dir(bio);
 	struct mapped_device *md = q->queuedata;
@@ -1412,19 +1409,12 @@
 			queue_io(md, bio);
 		else
 			bio_io_error(bio);
-		return 0;
+		return;
 	}
 
 	__split_and_process_bio(md, bio);
 	up_read(&md->io_lock);
-	return 0;
-}
-
-static int dm_make_request(struct request_queue *q, struct bio *bio)
-{
-	struct mapped_device *md = q->queuedata;
-
-	return md->saved_make_request_fn(q, bio); /* call __make_request() */
+	return;
 }
 
 static int dm_request_based(struct mapped_device *md)
@@ -1432,14 +1422,14 @@
 	return blk_queue_stackable(md->queue);
 }
 
-static int dm_request(struct request_queue *q, struct bio *bio)
+static void dm_request(struct request_queue *q, struct bio *bio)
 {
 	struct mapped_device *md = q->queuedata;
 
 	if (dm_request_based(md))
-		return dm_make_request(q, bio);
-
-	return _dm_request(q, bio);
+		blk_queue_bio(q, bio);
+	else
+		_dm_request(q, bio);
 }
 
 void dm_dispatch_request(struct request *rq)
@@ -2172,7 +2162,6 @@
 		return 0;
 
 	md->queue = q;
-	md->saved_make_request_fn = md->queue->make_request_fn;
 	dm_init_md_queue(md);
 	blk_queue_softirq_done(md->queue, dm_softirq_done);
 	blk_queue_prep_rq(md->queue, dm_prep_fn);
diff --git a/drivers/md/faulty.c b/drivers/md/faulty.c
index 23078da..5ef304d 100644
--- a/drivers/md/faulty.c
+++ b/drivers/md/faulty.c
@@ -169,7 +169,7 @@
 		conf->nfaults = n+1;
 }
 
-static int make_request(mddev_t *mddev, struct bio *bio)
+static void make_request(mddev_t *mddev, struct bio *bio)
 {
 	conf_t *conf = mddev->private;
 	int failit = 0;
@@ -181,7 +181,7 @@
 			 * just fail immediately
 			 */
 			bio_endio(bio, -EIO);
-			return 0;
+			return;
 		}
 
 		if (check_sector(conf, bio->bi_sector, bio->bi_sector+(bio->bi_size>>9),
@@ -211,15 +211,15 @@
 	}
 	if (failit) {
 		struct bio *b = bio_clone_mddev(bio, GFP_NOIO, mddev);
+
 		b->bi_bdev = conf->rdev->bdev;
 		b->bi_private = bio;
 		b->bi_end_io = faulty_fail;
-		generic_make_request(b);
-		return 0;
-	} else {
+		bio = b;
+	} else
 		bio->bi_bdev = conf->rdev->bdev;
-		return 1;
-	}
+
+	generic_make_request(bio);
 }
 
 static void status(struct seq_file *seq, mddev_t *mddev)
diff --git a/drivers/md/linear.c b/drivers/md/linear.c
index 6cd2c31..c6ee491 100644
--- a/drivers/md/linear.c
+++ b/drivers/md/linear.c
@@ -264,14 +264,14 @@
 	return 0;
 }
 
-static int linear_make_request (mddev_t *mddev, struct bio *bio)
+static void linear_make_request (mddev_t *mddev, struct bio *bio)
 {
 	dev_info_t *tmp_dev;
 	sector_t start_sector;
 
 	if (unlikely(bio->bi_rw & REQ_FLUSH)) {
 		md_flush_request(mddev, bio);
-		return 0;
+		return;
 	}
 
 	rcu_read_lock();
@@ -293,7 +293,7 @@
 		       (unsigned long long)start_sector);
 		rcu_read_unlock();
 		bio_io_error(bio);
-		return 0;
+		return;
 	}
 	if (unlikely(bio->bi_sector + (bio->bi_size >> 9) >
 		     tmp_dev->end_sector)) {
@@ -307,20 +307,17 @@
 
 		bp = bio_split(bio, end_sector - bio->bi_sector);
 
-		if (linear_make_request(mddev, &bp->bio1))
-			generic_make_request(&bp->bio1);
-		if (linear_make_request(mddev, &bp->bio2))
-			generic_make_request(&bp->bio2);
+		linear_make_request(mddev, &bp->bio1);
+		linear_make_request(mddev, &bp->bio2);
 		bio_pair_release(bp);
-		return 0;
+		return;
 	}
 		    
 	bio->bi_bdev = tmp_dev->rdev->bdev;
 	bio->bi_sector = bio->bi_sector - start_sector
 		+ tmp_dev->rdev->data_offset;
 	rcu_read_unlock();
-
-	return 1;
+	generic_make_request(bio);
 }
 
 static void linear_status (struct seq_file *seq, mddev_t *mddev)
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 5c95ccb..8f52d4e 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -335,18 +335,17 @@
  * 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 int md_make_request(struct request_queue *q, struct bio *bio)
+static void md_make_request(struct request_queue *q, struct bio *bio)
 {
 	const int rw = bio_data_dir(bio);
 	mddev_t *mddev = q->queuedata;
-	int rv;
 	int cpu;
 	unsigned int sectors;
 
 	if (mddev == NULL || mddev->pers == NULL
 	    || !mddev->ready) {
 		bio_io_error(bio);
-		return 0;
+		return;
 	}
 	smp_rmb(); /* Ensure implications of  'active' are visible */
 	rcu_read_lock();
@@ -371,7 +370,7 @@
 	 * go away inside make_request
 	 */
 	sectors = bio_sectors(bio);
-	rv = mddev->pers->make_request(mddev, bio);
+	mddev->pers->make_request(mddev, bio);
 
 	cpu = part_stat_lock();
 	part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]);
@@ -380,8 +379,6 @@
 
 	if (atomic_dec_and_test(&mddev->active_io) && mddev->suspended)
 		wake_up(&mddev->sb_wait);
-
-	return rv;
 }
 
 /* mddev_suspend makes sure no new requests are submitted
@@ -480,8 +477,7 @@
 		bio_endio(bio, 0);
 	else {
 		bio->bi_rw &= ~REQ_FLUSH;
-		if (mddev->pers->make_request(mddev, bio))
-			generic_make_request(bio);
+		mddev->pers->make_request(mddev, bio);
 	}
 
 	mddev->flush_bio = NULL;
diff --git a/drivers/md/md.h b/drivers/md/md.h
index 0a309dc..1509a3e 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -424,7 +424,7 @@
 	int level;
 	struct list_head list;
 	struct module *owner;
-	int (*make_request)(mddev_t *mddev, struct bio *bio);
+	void (*make_request)(mddev_t *mddev, struct bio *bio);
 	int (*run)(mddev_t *mddev);
 	int (*stop)(mddev_t *mddev);
 	void (*status)(struct seq_file *seq, mddev_t *mddev);
diff --git a/drivers/md/multipath.c b/drivers/md/multipath.c
index d5b5fb3..618dd9e 100644
--- a/drivers/md/multipath.c
+++ b/drivers/md/multipath.c
@@ -106,7 +106,7 @@
 	rdev_dec_pending(rdev, conf->mddev);
 }
 
-static int multipath_make_request(mddev_t *mddev, struct bio * bio)
+static void multipath_make_request(mddev_t *mddev, struct bio * bio)
 {
 	multipath_conf_t *conf = mddev->private;
 	struct multipath_bh * mp_bh;
@@ -114,7 +114,7 @@
 
 	if (unlikely(bio->bi_rw & REQ_FLUSH)) {
 		md_flush_request(mddev, bio);
-		return 0;
+		return;
 	}
 
 	mp_bh = mempool_alloc(conf->pool, GFP_NOIO);
@@ -126,7 +126,7 @@
 	if (mp_bh->path < 0) {
 		bio_endio(bio, -EIO);
 		mempool_free(mp_bh, conf->pool);
-		return 0;
+		return;
 	}
 	multipath = conf->multipaths + mp_bh->path;
 
@@ -137,7 +137,7 @@
 	mp_bh->bio.bi_end_io = multipath_end_request;
 	mp_bh->bio.bi_private = mp_bh;
 	generic_make_request(&mp_bh->bio);
-	return 0;
+	return;
 }
 
 static void multipath_status (struct seq_file *seq, mddev_t *mddev)
diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index e86bf36..4066615 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -466,7 +466,7 @@
 	}
 }
 
-static int raid0_make_request(mddev_t *mddev, struct bio *bio)
+static void raid0_make_request(mddev_t *mddev, struct bio *bio)
 {
 	unsigned int chunk_sects;
 	sector_t sector_offset;
@@ -475,7 +475,7 @@
 
 	if (unlikely(bio->bi_rw & REQ_FLUSH)) {
 		md_flush_request(mddev, bio);
-		return 0;
+		return;
 	}
 
 	chunk_sects = mddev->chunk_sectors;
@@ -495,13 +495,10 @@
 		else
 			bp = bio_split(bio, chunk_sects -
 				       sector_div(sector, chunk_sects));
-		if (raid0_make_request(mddev, &bp->bio1))
-			generic_make_request(&bp->bio1);
-		if (raid0_make_request(mddev, &bp->bio2))
-			generic_make_request(&bp->bio2);
-
+		raid0_make_request(mddev, &bp->bio1);
+		raid0_make_request(mddev, &bp->bio2);
 		bio_pair_release(bp);
-		return 0;
+		return;
 	}
 
 	sector_offset = bio->bi_sector;
@@ -511,10 +508,9 @@
 	bio->bi_bdev = tmp_dev->bdev;
 	bio->bi_sector = sector_offset + zone->dev_start +
 		tmp_dev->data_offset;
-	/*
-	 * Let the main block layer submit the IO and resolve recursion:
-	 */
-	return 1;
+
+	generic_make_request(bio);
+	return;
 
 bad_map:
 	printk("md/raid0:%s: make_request bug: can't convert block across chunks"
@@ -523,7 +519,7 @@
 	       (unsigned long long)bio->bi_sector, bio->bi_size >> 10);
 
 	bio_io_error(bio);
-	return 0;
+	return;
 }
 
 static void raid0_status(struct seq_file *seq, mddev_t *mddev)
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index d9587df..2948a52 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -785,7 +785,7 @@
 	PRINTK("%dB behind alloc failed, doing sync I/O\n", bio->bi_size);
 }
 
-static int make_request(mddev_t *mddev, struct bio * bio)
+static void make_request(mddev_t *mddev, struct bio * bio)
 {
 	conf_t *conf = mddev->private;
 	mirror_info_t *mirror;
@@ -870,7 +870,7 @@
 		if (rdisk < 0) {
 			/* couldn't find anywhere to read from */
 			raid_end_bio_io(r1_bio);
-			return 0;
+			return;
 		}
 		mirror = conf->mirrors + rdisk;
 
@@ -928,7 +928,7 @@
 			goto read_again;
 		} else
 			generic_make_request(read_bio);
-		return 0;
+		return;
 	}
 
 	/*
@@ -1123,8 +1123,6 @@
 
 	if (do_sync || !bitmap || !plugged)
 		md_wakeup_thread(mddev->thread);
-
-	return 0;
 }
 
 static void status(struct seq_file *seq, mddev_t *mddev)
@@ -2174,7 +2172,6 @@
 		bio->bi_next = NULL;
 		bio->bi_flags &= ~(BIO_POOL_MASK-1);
 		bio->bi_flags |= 1 << BIO_UPTODATE;
-		bio->bi_comp_cpu = -1;
 		bio->bi_rw = READ;
 		bio->bi_vcnt = 0;
 		bio->bi_idx = 0;
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 0cd9672..ea5fc0b 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -830,7 +830,7 @@
 	spin_unlock_irq(&conf->resync_lock);
 }
 
-static int make_request(mddev_t *mddev, struct bio * bio)
+static void make_request(mddev_t *mddev, struct bio * bio)
 {
 	conf_t *conf = mddev->private;
 	mirror_info_t *mirror;
@@ -849,7 +849,7 @@
 
 	if (unlikely(bio->bi_rw & REQ_FLUSH)) {
 		md_flush_request(mddev, bio);
-		return 0;
+		return;
 	}
 
 	/* If this request crosses a chunk boundary, we need to
@@ -881,10 +881,8 @@
 		conf->nr_waiting++;
 		spin_unlock_irq(&conf->resync_lock);
 
-		if (make_request(mddev, &bp->bio1))
-			generic_make_request(&bp->bio1);
-		if (make_request(mddev, &bp->bio2))
-			generic_make_request(&bp->bio2);
+		make_request(mddev, &bp->bio1);
+		make_request(mddev, &bp->bio2);
 
 		spin_lock_irq(&conf->resync_lock);
 		conf->nr_waiting--;
@@ -892,14 +890,14 @@
 		spin_unlock_irq(&conf->resync_lock);
 
 		bio_pair_release(bp);
-		return 0;
+		return;
 	bad_map:
 		printk("md/raid10:%s: make_request bug: can't convert block across chunks"
 		       " or bigger than %dk %llu %d\n", mdname(mddev), chunk_sects/2,
 		       (unsigned long long)bio->bi_sector, bio->bi_size >> 10);
 
 		bio_io_error(bio);
-		return 0;
+		return;
 	}
 
 	md_write_start(mddev, bio);
@@ -942,7 +940,7 @@
 		slot = r10_bio->read_slot;
 		if (disk < 0) {
 			raid_end_bio_io(r10_bio);
-			return 0;
+			return;
 		}
 		mirror = conf->mirrors + disk;
 
@@ -990,7 +988,7 @@
 			goto read_again;
 		} else
 			generic_make_request(read_bio);
-		return 0;
+		return;
 	}
 
 	/*
@@ -1158,7 +1156,6 @@
 
 	if (do_sync || !mddev->bitmap || !plugged)
 		md_wakeup_thread(mddev->thread);
-	return 0;
 }
 
 static void status(struct seq_file *seq, mddev_t *mddev)
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index ac5e8b5..83f2c44 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -3695,7 +3695,7 @@
 	return sh;
 }
 
-static int make_request(mddev_t *mddev, struct bio * bi)
+static void make_request(mddev_t *mddev, struct bio * bi)
 {
 	raid5_conf_t *conf = mddev->private;
 	int dd_idx;
@@ -3708,7 +3708,7 @@
 
 	if (unlikely(bi->bi_rw & REQ_FLUSH)) {
 		md_flush_request(mddev, bi);
-		return 0;
+		return;
 	}
 
 	md_write_start(mddev, bi);
@@ -3716,7 +3716,7 @@
 	if (rw == READ &&
 	     mddev->reshape_position == MaxSector &&
 	     chunk_aligned_read(mddev,bi))
-		return 0;
+		return;
 
 	logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
 	last_sector = bi->bi_sector + (bi->bi_size>>9);
@@ -3851,8 +3851,6 @@
 
 		bio_endio(bi, 0);
 	}
-
-	return 0;
 }
 
 static sector_t raid5_size(mddev_t *mddev, sector_t sectors, int raid_disks);
diff --git a/drivers/s390/block/dcssblk.c b/drivers/s390/block/dcssblk.c
index 9b43ae9..a5a55da2 100644
--- a/drivers/s390/block/dcssblk.c
+++ b/drivers/s390/block/dcssblk.c
@@ -27,7 +27,7 @@
 
 static int dcssblk_open(struct block_device *bdev, fmode_t mode);
 static int dcssblk_release(struct gendisk *disk, fmode_t mode);
-static int dcssblk_make_request(struct request_queue *q, struct bio *bio);
+static void dcssblk_make_request(struct request_queue *q, struct bio *bio);
 static int dcssblk_direct_access(struct block_device *bdev, sector_t secnum,
 				 void **kaddr, unsigned long *pfn);
 
@@ -814,7 +814,7 @@
 	return rc;
 }
 
-static int
+static void
 dcssblk_make_request(struct request_queue *q, struct bio *bio)
 {
 	struct dcssblk_dev_info *dev_info;
@@ -871,10 +871,9 @@
 		bytes_done += bvec->bv_len;
 	}
 	bio_endio(bio, 0);
-	return 0;
+	return;
 fail:
 	bio_io_error(bio);
-	return 0;
 }
 
 static int
diff --git a/drivers/s390/block/xpram.c b/drivers/s390/block/xpram.c
index 1f6a4d8..98f3e4a 100644
--- a/drivers/s390/block/xpram.c
+++ b/drivers/s390/block/xpram.c
@@ -181,7 +181,7 @@
 /*
  * Block device make request function.
  */
-static int xpram_make_request(struct request_queue *q, struct bio *bio)
+static void xpram_make_request(struct request_queue *q, struct bio *bio)
 {
 	xpram_device_t *xdev = bio->bi_bdev->bd_disk->private_data;
 	struct bio_vec *bvec;
@@ -221,10 +221,9 @@
 	}
 	set_bit(BIO_UPTODATE, &bio->bi_flags);
 	bio_endio(bio, 0);
-	return 0;
+	return;
 fail:
 	bio_io_error(bio);
-	return 0;
 }
 
 static int xpram_getgeo(struct block_device *bdev, struct hd_geometry *geo)
diff --git a/drivers/staging/zram/zram_drv.c b/drivers/staging/zram/zram_drv.c
index d70ec1a..02589ca 100644
--- a/drivers/staging/zram/zram_drv.c
+++ b/drivers/staging/zram/zram_drv.c
@@ -556,24 +556,22 @@
 /*
  * Handler function for all zram I/O requests.
  */
-static int zram_make_request(struct request_queue *queue, struct bio *bio)
+static void zram_make_request(struct request_queue *queue, struct bio *bio)
 {
 	struct zram *zram = queue->queuedata;
 
 	if (!valid_io_request(zram, bio)) {
 		zram_stat64_inc(zram, &zram->stats.invalid_io);
 		bio_io_error(bio);
-		return 0;
+		return;
 	}
 
 	if (unlikely(!zram->init_done) && zram_init_device(zram)) {
 		bio_io_error(bio);
-		return 0;
+		return;
 	}
 
 	__zram_make_request(zram, bio, bio_data_dir(bio));
-
-	return 0;
 }
 
 void zram_reset_device(struct zram *zram)
diff --git a/fs/bio.c b/fs/bio.c
index 9bfade8..41c93c7 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -255,7 +255,6 @@
 {
 	memset(bio, 0, sizeof(*bio));
 	bio->bi_flags = 1 << BIO_UPTODATE;
-	bio->bi_comp_cpu = -1;
 	atomic_set(&bio->bi_cnt, 1);
 }
 EXPORT_SYMBOL(bio_init);
diff --git a/include/linux/bio.h b/include/linux/bio.h
index ce33e68..a3c071c 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -269,14 +269,6 @@
 extern unsigned int bvec_nr_vecs(unsigned short idx);
 
 /*
- * Allow queuer to specify a completion CPU for this bio
- */
-static inline void bio_set_completion_cpu(struct bio *bio, unsigned int cpu)
-{
-	bio->bi_comp_cpu = cpu;
-}
-
-/*
  * bio_set is used to allow other portions of the IO system to
  * allocate their own private memory pools for bio and iovec structures.
  * These memory pools in turn all allocate from the bio_slab
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 71fc53b..4053cbd 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -59,8 +59,6 @@
 
 	unsigned int		bi_max_vecs;	/* max bvl_vecs we can hold */
 
-	unsigned int		bi_comp_cpu;	/* completion CPU */
-
 	atomic_t		bi_cnt;		/* pin count */
 
 	struct bio_vec		*bi_io_vec;	/* the actual vec list */
@@ -93,11 +91,10 @@
 #define BIO_BOUNCED	5	/* bio is a bounce bio */
 #define BIO_USER_MAPPED 6	/* contains user pages */
 #define BIO_EOPNOTSUPP	7	/* not supported */
-#define BIO_CPU_AFFINE	8	/* complete bio on same CPU as submitted */
-#define BIO_NULL_MAPPED 9	/* contains invalid user pages */
-#define BIO_FS_INTEGRITY 10	/* fs owns integrity data, not block layer */
-#define BIO_QUIET	11	/* Make BIO Quiet */
-#define BIO_MAPPED_INTEGRITY 12/* integrity metadata has been remapped */
+#define BIO_NULL_MAPPED 8	/* contains invalid user pages */
+#define BIO_FS_INTEGRITY 9	/* fs owns integrity data, not block layer */
+#define BIO_QUIET	10	/* Make BIO Quiet */
+#define BIO_MAPPED_INTEGRITY 11/* integrity metadata has been remapped */
 #define bio_flagged(bio, flag)	((bio)->bi_flags & (1 << (flag)))
 
 /*
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 7fbaa91..5267cd2 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -195,7 +195,7 @@
 #include <linux/elevator.h>
 
 typedef void (request_fn_proc) (struct request_queue *q);
-typedef int (make_request_fn) (struct request_queue *q, struct bio *bio);
+typedef void (make_request_fn) (struct request_queue *q, struct bio *bio);
 typedef int (prep_rq_fn) (struct request_queue *, struct request *);
 typedef void (unprep_rq_fn) (struct request_queue *, struct request *);
 
@@ -680,6 +680,8 @@
 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
 			 struct scsi_ioctl_command __user *);
 
+extern void blk_queue_bio(struct request_queue *q, struct bio *bio);
+
 /*
  * A queue has just exitted congestion.  Note this in the global counter of
  * congested queues, and wake up anyone who was waiting for requests to be
@@ -863,16 +865,22 @@
 extern void blk_put_queue(struct request_queue *);
 
 /*
- * Note: Code in between changing the blk_plug list/cb_list or element of such
- * lists is preemptable, but such code can't do sleep (or be very careful),
- * otherwise data is corrupted. For details, please check schedule() where
- * blk_schedule_flush_plug() is called.
+ * blk_plug permits building a queue of related requests by holding the I/O
+ * fragments for a short period. This allows merging of sequential requests
+ * into single larger request. As the requests are moved from a per-task list to
+ * the device's request_queue in a batch, this results in improved scalability
+ * as the lock contention for request_queue lock is reduced.
+ *
+ * It is ok not to disable preemption when adding the request to the plug list
+ * or when attempting a merge, because blk_schedule_flush_list() will only flush
+ * the plug list when the task sleeps by itself. For details, please see
+ * schedule() where blk_schedule_flush_plug() is called.
  */
 struct blk_plug {
-	unsigned long magic;
-	struct list_head list;
-	struct list_head cb_list;
-	unsigned int should_sort;
+	unsigned long magic; /* detect uninitialized use-cases */
+	struct list_head list; /* requests */
+	struct list_head cb_list; /* md requires an unplug callback */
+	unsigned int should_sort; /* list to be sorted before flushing? */
 };
 #define BLK_MAX_REQUEST_COUNT 16
 
@@ -1189,20 +1197,6 @@
 }
 #endif
 
-#ifdef CONFIG_BLK_DEV_THROTTLING
-extern int blk_throtl_init(struct request_queue *q);
-extern void blk_throtl_exit(struct request_queue *q);
-extern int blk_throtl_bio(struct request_queue *q, struct bio **bio);
-#else /* CONFIG_BLK_DEV_THROTTLING */
-static inline int blk_throtl_bio(struct request_queue *q, struct bio **bio)
-{
-	return 0;
-}
-
-static inline int blk_throtl_init(struct request_queue *q) { return 0; }
-static inline int blk_throtl_exit(struct request_queue *q) { return 0; }
-#endif /* CONFIG_BLK_DEV_THROTTLING */
-
 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
 	MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
diff --git a/include/linux/elevator.h b/include/linux/elevator.h
index d800d51..1d0f7a2 100644
--- a/include/linux/elevator.h
+++ b/include/linux/elevator.h
@@ -38,6 +38,12 @@
 	elevator_merged_fn *elevator_merged_fn;
 	elevator_merge_req_fn *elevator_merge_req_fn;
 	elevator_allow_merge_fn *elevator_allow_merge_fn;
+
+	/*
+	 * Used for both plugged list and elevator merging and in the
+	 * former case called without queue_lock.  Read comment on top of
+	 * attempt_plug_merge() for details.
+	 */
 	elevator_bio_merged_fn *elevator_bio_merged_fn;
 
 	elevator_dispatch_fn *elevator_dispatch_fn;
diff --git a/kernel/sys.c b/kernel/sys.c
index 18ee1d2..1dbbe69 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1172,7 +1172,7 @@
 static int override_release(char __user *release, int len)
 {
 	int ret = 0;
-	char buf[len];
+	char buf[65];
 
 	if (current->personality & UNAME26) {
 		char *rest = UTS_RELEASE;
diff --git a/mm/bounce.c b/mm/bounce.c
index 1481de6..434fb4f 100644
--- a/mm/bounce.c
+++ b/mm/bounce.c
@@ -14,6 +14,7 @@
 #include <linux/init.h>
 #include <linux/hash.h>
 #include <linux/highmem.h>
+#include <linux/bootmem.h>
 #include <asm/tlbflush.h>
 
 #include <trace/events/block.h>
@@ -26,12 +27,10 @@
 #ifdef CONFIG_HIGHMEM
 static __init int init_emergency_pool(void)
 {
-	struct sysinfo i;
-	si_meminfo(&i);
-	si_swapinfo(&i);
-
-	if (!i.totalhigh)
+#ifndef CONFIG_MEMORY_HOTPLUG
+	if (max_pfn <= max_low_pfn)
 		return 0;
+#endif
 
 	page_pool = mempool_create_page_pool(POOL_SIZE, 0);
 	BUG_ON(!page_pool);