Merge ../linux-2.6 by hand

20 files changed, 613 insertions, 1023 deletions

diff --git a/drivers/block/Kconfig.iosched b/drivers/block/Kconfig.iosched
index 6070a480600b..5b90d2fa63b8 100644
--- a/drivers/block/Kconfig.iosched
+++ b/drivers/block/Kconfig.iosched
@@ -38,4 +38,32 @@ config IOSCHED_CFQ
           among all processes in the system. It should provide a fair
           working environment, suitable for desktop systems.
 
+choice
+        prompt "Default I/O scheduler"
+        default DEFAULT_AS
+        help
+          Select the I/O scheduler which will be used by default for all
+          block devices.
+
+        config DEFAULT_AS
+                bool "Anticipatory" if IOSCHED_AS
+
+        config DEFAULT_DEADLINE
+                bool "Deadline" if IOSCHED_DEADLINE
+
+        config DEFAULT_CFQ
+                bool "CFQ" if IOSCHED_CFQ
+
+        config DEFAULT_NOOP
+                bool "No-op"
+
+endchoice
+
+config DEFAULT_IOSCHED
+        string
+        default "anticipatory" if DEFAULT_AS
+        default "deadline" if DEFAULT_DEADLINE
+        default "cfq" if DEFAULT_CFQ
+        default "noop" if DEFAULT_NOOP
+
 endmenu
diff --git a/drivers/block/aoe/aoe.h b/drivers/block/aoe/aoe.h
index 0e9e586e9ba3..881c48d941b7 100644
--- a/drivers/block/aoe/aoe.h
+++ b/drivers/block/aoe/aoe.h
@@ -1,5 +1,5 @@
 /* Copyright (c) 2004 Coraid, Inc.  See COPYING for GPL terms. */
-#define VERSION "12"
+#define VERSION "14"
 #define AOE_MAJOR 152
 #define DEVICE_NAME "aoe"
 
diff --git a/drivers/block/aoe/aoechr.c b/drivers/block/aoe/aoechr.c
index 45a243096187..41ae0ede619a 100644
--- a/drivers/block/aoe/aoechr.c
+++ b/drivers/block/aoe/aoechr.c
@@ -224,7 +224,7 @@ aoechr_init(void)
                 return PTR_ERR(aoe_class);
         }
         for (i = 0; i < ARRAY_SIZE(chardevs); ++i)
-                class_device_create(aoe_class,
+                class_device_create(aoe_class, NULL,
                                         MKDEV(AOE_MAJOR, chardevs[i].minor),
                                         NULL, chardevs[i].name);
 
diff --git a/drivers/block/aoe/aoecmd.c b/drivers/block/aoe/aoecmd.c
index b5be4b7d7b5b..5c9c7c1a3d4c 100644
--- a/drivers/block/aoe/aoecmd.c
+++ b/drivers/block/aoe/aoecmd.c
@@ -8,6 +8,7 @@
 #include <linux/blkdev.h>
 #include <linux/skbuff.h>
 #include <linux/netdevice.h>
+#include <asm/unaligned.h>
 #include "aoe.h"
 
 #define TIMERTICK (HZ / 10)
@@ -311,16 +312,16 @@ ataid_complete(struct aoedev *d, unsigned char *id)
         u16 n;
 
         /* word 83: command set supported */
-        n = le16_to_cpup((__le16 *) &id[83<<1]);
+        n = le16_to_cpu(get_unaligned((__le16 *) &id[83<<1]));
 
         /* word 86: command set/feature enabled */
-        n |= le16_to_cpup((__le16 *) &id[86<<1]);
+        n |= le16_to_cpu(get_unaligned((__le16 *) &id[86<<1]));
 
         if (n & (1<<10)) {      /* bit 10: LBA 48 */
                 d->flags |= DEVFL_EXT;
 
                 /* word 100: number lba48 sectors */
-                ssize = le64_to_cpup((__le64 *) &id[100<<1]);
+                ssize = le64_to_cpu(get_unaligned((__le64 *) &id[100<<1]));
 
                 /* set as in ide-disk.c:init_idedisk_capacity */
                 d->geo.cylinders = ssize;
@@ -331,12 +332,12 @@ ataid_complete(struct aoedev *d, unsigned char *id)
                 d->flags &= ~DEVFL_EXT;
 
                 /* number lba28 sectors */
-                ssize = le32_to_cpup((__le32 *) &id[60<<1]);
+                ssize = le32_to_cpu(get_unaligned((__le32 *) &id[60<<1]));
 
                 /* NOTE: obsolete in ATA 6 */
-                d->geo.cylinders = le16_to_cpup((__le16 *) &id[54<<1]);
-                d->geo.heads = le16_to_cpup((__le16 *) &id[55<<1]);
-                d->geo.sectors = le16_to_cpup((__le16 *) &id[56<<1]);
+                d->geo.cylinders = le16_to_cpu(get_unaligned((__le16 *) &id[54<<1]));
+                d->geo.heads = le16_to_cpu(get_unaligned((__le16 *) &id[55<<1]));
+                d->geo.sectors = le16_to_cpu(get_unaligned((__le16 *) &id[56<<1]));
         }
         d->ssize = ssize;
         d->geo.start = 0;
diff --git a/drivers/block/as-iosched.c b/drivers/block/as-iosched.c
index 95c0a3690b0f..c6744ff38294 100644
--- a/drivers/block/as-iosched.c
+++ b/drivers/block/as-iosched.c
@@ -98,7 +98,6 @@ struct as_data {
 
         struct as_rq *next_arq[2];      /* next in sort order */
         sector_t last_sector[2];        /* last REQ_SYNC & REQ_ASYNC sectors */
-        struct list_head *dispatch;     /* driver dispatch queue */
         struct list_head *hash;         /* request hash */
 
         unsigned long exit_prob;        /* probability a task will exit while
@@ -239,6 +238,25 @@ static struct io_context *as_get_io_context(void)
         return ioc;
 }
 
+static void as_put_io_context(struct as_rq *arq)
+{
+        struct as_io_context *aic;
+
+        if (unlikely(!arq->io_context))
+                return;
+
+        aic = arq->io_context->aic;
+
+        if (arq->is_sync == REQ_SYNC && aic) {
+                spin_lock(&aic->lock);
+                set_bit(AS_TASK_IORUNNING, &aic->state);
+                aic->last_end_request = jiffies;
+                spin_unlock(&aic->lock);
+        }
+
+        put_io_context(arq->io_context);
+}
+
 /*
  * the back merge hash support functions
  */
@@ -261,14 +279,6 @@ static inline void as_del_arq_hash(struct as_rq *arq)
                 __as_del_arq_hash(arq);
 }
 
-static void as_remove_merge_hints(request_queue_t *q, struct as_rq *arq)
-{
-        as_del_arq_hash(arq);
-
-        if (q->last_merge == arq->request)
-                q->last_merge = NULL;
-}
-
 static void as_add_arq_hash(struct as_data *ad, struct as_rq *arq)
 {
         struct request *rq = arq->request;
@@ -312,7 +322,7 @@ static struct request *as_find_arq_hash(struct as_data *ad, sector_t offset)
                 BUG_ON(!arq->on_hash);
 
                 if (!rq_mergeable(__rq)) {
-                        as_remove_merge_hints(ad->q, arq);
+                        as_del_arq_hash(arq);
                         continue;
                 }
 
@@ -950,23 +960,12 @@ static void as_completed_request(request_queue_t *q, struct request *rq)
 
         WARN_ON(!list_empty(&rq->queuelist));
 
-        if (arq->state == AS_RQ_PRESCHED) {
-                WARN_ON(arq->io_context);
-                goto out;
-        }
-
-        if (arq->state == AS_RQ_MERGED)
-                goto out_ioc;
-
         if (arq->state != AS_RQ_REMOVED) {
                 printk("arq->state %d\n", arq->state);
                 WARN_ON(1);
                 goto out;
         }
 
-        if (!blk_fs_request(rq))
-                goto out;
-
         if (ad->changed_batch && ad->nr_dispatched == 1) {
                 kblockd_schedule_work(&ad->antic_work);
                 ad->changed_batch = 0;
@@ -1001,21 +1000,7 @@ static void as_completed_request(request_queue_t *q, struct request *rq)
                 }
         }
 
-out_ioc:
-        if (!arq->io_context)
-                goto out;
-
-        if (arq->is_sync == REQ_SYNC) {
-                struct as_io_context *aic = arq->io_context->aic;
-                if (aic) {
-                        spin_lock(&aic->lock);
-                        set_bit(AS_TASK_IORUNNING, &aic->state);
-                        aic->last_end_request = jiffies;
-                        spin_unlock(&aic->lock);
-                }
-        }
-
-        put_io_context(arq->io_context);
+        as_put_io_context(arq);
 out:
         arq->state = AS_RQ_POSTSCHED;
 }
@@ -1047,73 +1032,11 @@ static void as_remove_queued_request(request_queue_t *q, struct request *rq)
                 ad->next_arq[data_dir] = as_find_next_arq(ad, arq);
 
         list_del_init(&arq->fifo);
-        as_remove_merge_hints(q, arq);
+        as_del_arq_hash(arq);
         as_del_arq_rb(ad, arq);
 }
 
 /*
- * as_remove_dispatched_request is called to remove a request which has gone
- * to the dispatch list.
- */
-static void as_remove_dispatched_request(request_queue_t *q, struct request *rq)
-{
-        struct as_rq *arq = RQ_DATA(rq);
-        struct as_io_context *aic;
-
-        if (!arq) {
-                WARN_ON(1);
-                return;
-        }
-
-        WARN_ON(arq->state != AS_RQ_DISPATCHED);
-        WARN_ON(ON_RB(&arq->rb_node));
-        if (arq->io_context && arq->io_context->aic) {
-                aic = arq->io_context->aic;
-                if (aic) {
-                        WARN_ON(!atomic_read(&aic->nr_dispatched));
-                        atomic_dec(&aic->nr_dispatched);
-                }
-        }
-}
-
-/*
- * as_remove_request is called when a driver has finished with a request.
- * This should be only called for dispatched requests, but for some reason
- * a POWER4 box running hwscan it does not.
- */
-static void as_remove_request(request_queue_t *q, struct request *rq)
-{
-        struct as_rq *arq = RQ_DATA(rq);
-
-        if (unlikely(arq->state == AS_RQ_NEW))
-                goto out;
-
-        if (ON_RB(&arq->rb_node)) {
-                if (arq->state != AS_RQ_QUEUED) {
-                        printk("arq->state %d\n", arq->state);
-                        WARN_ON(1);
-                        goto out;
-                }
-                /*
-                 * We'll lose the aliased request(s) here. I don't think this
-                 * will ever happen, but if it does, hopefully someone will
-                 * report it.
-                 */
-                WARN_ON(!list_empty(&rq->queuelist));
-                as_remove_queued_request(q, rq);
-        } else {
-                if (arq->state != AS_RQ_DISPATCHED) {
-                        printk("arq->state %d\n", arq->state);
-                        WARN_ON(1);
-                        goto out;
-                }
-                as_remove_dispatched_request(q, rq);
-        }
-out:
-        arq->state = AS_RQ_REMOVED;
-}
-
-/*
  * as_fifo_expired returns 0 if there are no expired reads on the fifo,
  * 1 otherwise.  It is ratelimited so that we only perform the check once per
  * `fifo_expire' interval.  Otherwise a large number of expired requests
@@ -1165,7 +1088,6 @@ static inline int as_batch_expired(struct as_data *ad)
 static void as_move_to_dispatch(struct as_data *ad, struct as_rq *arq)
 {
         struct request *rq = arq->request;
-        struct list_head *insert;
         const int data_dir = arq->is_sync;
 
         BUG_ON(!ON_RB(&arq->rb_node));
@@ -1198,13 +1120,13 @@ static void as_move_to_dispatch(struct as_data *ad, struct as_rq *arq)
         /*
          * take it off the sort and fifo list, add to dispatch queue
          */
-        insert = ad->dispatch->prev;
-
         while (!list_empty(&rq->queuelist)) {
                 struct request *__rq = list_entry_rq(rq->queuelist.next);
                 struct as_rq *__arq = RQ_DATA(__rq);
 
-                list_move_tail(&__rq->queuelist, ad->dispatch);
+                list_del(&__rq->queuelist);
+
+                elv_dispatch_add_tail(ad->q, __rq);
 
                 if (__arq->io_context && __arq->io_context->aic)
                         atomic_inc(&__arq->io_context->aic->nr_dispatched);
@@ -1218,7 +1140,8 @@ static void as_move_to_dispatch(struct as_data *ad, struct as_rq *arq)
         as_remove_queued_request(ad->q, rq);
         WARN_ON(arq->state != AS_RQ_QUEUED);
 
-        list_add(&rq->queuelist, insert);
+        elv_dispatch_sort(ad->q, rq);
+
         arq->state = AS_RQ_DISPATCHED;
         if (arq->io_context && arq->io_context->aic)
                 atomic_inc(&arq->io_context->aic->nr_dispatched);
@@ -1230,12 +1153,42 @@ static void as_move_to_dispatch(struct as_data *ad, struct as_rq *arq)
  * read/write expire, batch expire, etc, and moves it to the dispatch
  * queue. Returns 1 if a request was found, 0 otherwise.
  */
-static int as_dispatch_request(struct as_data *ad)
+static int as_dispatch_request(request_queue_t *q, int force)
 {
+        struct as_data *ad = q->elevator->elevator_data;
         struct as_rq *arq;
         const int reads = !list_empty(&ad->fifo_list[REQ_SYNC]);
         const int writes = !list_empty(&ad->fifo_list[REQ_ASYNC]);
 
+        if (unlikely(force)) {
+                /*
+                 * Forced dispatch, accounting is useless.  Reset
+                 * accounting states and dump fifo_lists.  Note that
+                 * batch_data_dir is reset to REQ_SYNC to avoid
+                 * screwing write batch accounting as write batch
+                 * accounting occurs on W->R transition.
+                 */
+                int dispatched = 0;
+
+                ad->batch_data_dir = REQ_SYNC;
+                ad->changed_batch = 0;
+                ad->new_batch = 0;
+
+                while (ad->next_arq[REQ_SYNC]) {
+                        as_move_to_dispatch(ad, ad->next_arq[REQ_SYNC]);
+                        dispatched++;
+                }
+                ad->last_check_fifo[REQ_SYNC] = jiffies;
+
+                while (ad->next_arq[REQ_ASYNC]) {
+                        as_move_to_dispatch(ad, ad->next_arq[REQ_ASYNC]);
+                        dispatched++;
+                }
+                ad->last_check_fifo[REQ_ASYNC] = jiffies;
+
+                return dispatched;
+        }
+
         /* Signal that the write batch was uncontended, so we can't time it */
         if (ad->batch_data_dir == REQ_ASYNC && !reads) {
                 if (ad->current_write_count == 0 || !writes)
@@ -1359,20 +1312,6 @@ fifo_expired:
         return 1;
 }
 
-static struct request *as_next_request(request_queue_t *q)
-{
-        struct as_data *ad = q->elevator->elevator_data;
-        struct request *rq = NULL;
-
-        /*
-         * if there are still requests on the dispatch queue, grab the first
-         */
-        if (!list_empty(ad->dispatch) || as_dispatch_request(ad))
-                rq = list_entry_rq(ad->dispatch->next);
-
-        return rq;
-}
-
 /*
  * Add arq to a list behind alias
  */
@@ -1404,17 +1343,26 @@ as_add_aliased_request(struct as_data *ad, struct as_rq *arq, struct as_rq *alia
         /*
          * Don't want to have to handle merges.
          */
-        as_remove_merge_hints(ad->q, arq);
+        as_del_arq_hash(arq);
+        arq->request->flags |= REQ_NOMERGE;
 }
 
 /*
  * add arq to rbtree and fifo
  */
-static void as_add_request(struct as_data *ad, struct as_rq *arq)
+static void as_add_request(request_queue_t *q, struct request *rq)
 {
+        struct as_data *ad = q->elevator->elevator_data;
+        struct as_rq *arq = RQ_DATA(rq);
         struct as_rq *alias;
         int data_dir;
 
+        if (arq->state != AS_RQ_PRESCHED) {
+                printk("arq->state: %d\n", arq->state);
+                WARN_ON(1);
+        }
+        arq->state = AS_RQ_NEW;
+
         if (rq_data_dir(arq->request) == READ
                         || current->flags&PF_SYNCWRITE)
                 arq->is_sync = 1;
@@ -1437,12 +1385,8 @@ static void as_add_request(struct as_data *ad, struct as_rq *arq)
                 arq->expires = jiffies + ad->fifo_expire[data_dir];
                 list_add_tail(&arq->fifo, &ad->fifo_list[data_dir]);
 
-                if (rq_mergeable(arq->request)) {
+                if (rq_mergeable(arq->request))
                         as_add_arq_hash(ad, arq);
-
-                        if (!ad->q->last_merge)
-                                ad->q->last_merge = arq->request;
-                }
                 as_update_arq(ad, arq); /* keep state machine up to date */
 
         } else {
@@ -1463,96 +1407,24 @@ static void as_add_request(struct as_data *ad, struct as_rq *arq)
         arq->state = AS_RQ_QUEUED;
 }
 
-static void as_deactivate_request(request_queue_t *q, struct request *rq)
+static void as_activate_request(request_queue_t *q, struct request *rq)
 {
-        struct as_data *ad = q->elevator->elevator_data;
         struct as_rq *arq = RQ_DATA(rq);
 
-        if (arq) {
-                if (arq->state == AS_RQ_REMOVED) {
-                        arq->state = AS_RQ_DISPATCHED;
-                        if (arq->io_context && arq->io_context->aic)
-                                atomic_inc(&arq->io_context->aic->nr_dispatched);
-                }
-        } else
-                WARN_ON(blk_fs_request(rq)
-                        && (!(rq->flags & (REQ_HARDBARRIER|REQ_SOFTBARRIER))) );
-
-        /* Stop anticipating - let this request get through */
-        as_antic_stop(ad);
-}
-
-/*
- * requeue the request. The request has not been completed, nor is it a
- * new request, so don't touch accounting.
- */
-static void as_requeue_request(request_queue_t *q, struct request *rq)
-{
-        as_deactivate_request(q, rq);
-        list_add(&rq->queuelist, &q->queue_head);
-}
-
-/*
- * Account a request that is inserted directly onto the dispatch queue.
- * arq->io_context->aic->nr_dispatched should not need to be incremented
- * because only new requests should come through here: requeues go through
- * our explicit requeue handler.
- */
-static void as_account_queued_request(struct as_data *ad, struct request *rq)
-{
-        if (blk_fs_request(rq)) {
-                struct as_rq *arq = RQ_DATA(rq);
-                arq->state = AS_RQ_DISPATCHED;
-                ad->nr_dispatched++;
-        }
+        WARN_ON(arq->state != AS_RQ_DISPATCHED);
+        arq->state = AS_RQ_REMOVED;
+        if (arq->io_context && arq->io_context->aic)
+                atomic_dec(&arq->io_context->aic->nr_dispatched);
 }
 
-static void
-as_insert_request(request_queue_t *q, struct request *rq, int where)
+static void as_deactivate_request(request_queue_t *q, struct request *rq)
 {
-        struct as_data *ad = q->elevator->elevator_data;
         struct as_rq *arq = RQ_DATA(rq);
 
-        if (arq) {
-                if (arq->state != AS_RQ_PRESCHED) {
-                        printk("arq->state: %d\n", arq->state);
-                        WARN_ON(1);
-                }
-                arq->state = AS_RQ_NEW;
-        }
-
-        /* barriers must flush the reorder queue */
-        if (unlikely(rq->flags & (REQ_SOFTBARRIER | REQ_HARDBARRIER)
-                        && where == ELEVATOR_INSERT_SORT)) {
-                WARN_ON(1);
-                where = ELEVATOR_INSERT_BACK;
-        }
-
-        switch (where) {
-                case ELEVATOR_INSERT_BACK:
-                        while (ad->next_arq[REQ_SYNC])
-                                as_move_to_dispatch(ad, ad->next_arq[REQ_SYNC]);
-
-                        while (ad->next_arq[REQ_ASYNC])
-                                as_move_to_dispatch(ad, ad->next_arq[REQ_ASYNC]);
-
-                        list_add_tail(&rq->queuelist, ad->dispatch);
-                        as_account_queued_request(ad, rq);
-                        as_antic_stop(ad);
-                        break;
-                case ELEVATOR_INSERT_FRONT:
-                        list_add(&rq->queuelist, ad->dispatch);
-                        as_account_queued_request(ad, rq);
-                        as_antic_stop(ad);
-                        break;
-                case ELEVATOR_INSERT_SORT:
-                        BUG_ON(!blk_fs_request(rq));
-                        as_add_request(ad, arq);
-                        break;
-                default:
-                        BUG();
-                        return;
-        }
+        WARN_ON(arq->state != AS_RQ_REMOVED);
+        arq->state = AS_RQ_DISPATCHED;
+        if (arq->io_context && arq->io_context->aic)
+                atomic_inc(&arq->io_context->aic->nr_dispatched);
 }
 
 /*
@@ -1565,12 +1437,8 @@ static int as_queue_empty(request_queue_t *q)
 {
         struct as_data *ad = q->elevator->elevator_data;
 
-        if (!list_empty(&ad->fifo_list[REQ_ASYNC])
-                || !list_empty(&ad->fifo_list[REQ_SYNC])
-                || !list_empty(ad->dispatch))
-                        return 0;
-
-        return 1;
+        return list_empty(&ad->fifo_list[REQ_ASYNC])
+                && list_empty(&ad->fifo_list[REQ_SYNC]);
 }
 
 static struct request *
@@ -1608,15 +1476,6 @@ as_merge(request_queue_t *q, struct request **req, struct bio *bio)
         int ret;
 
         /*
-         * try last_merge to avoid going to hash
-         */
-        ret = elv_try_last_merge(q, bio);
-        if (ret != ELEVATOR_NO_MERGE) {
-                __rq = q->last_merge;
-                goto out_insert;
-        }
-
-        /*
          * see if the merge hash can satisfy a back merge
          */
         __rq = as_find_arq_hash(ad, bio->bi_sector);
@@ -1644,9 +1503,6 @@ as_merge(request_queue_t *q, struct request **req, struct bio *bio)
 
         return ELEVATOR_NO_MERGE;
 out:
-        if (rq_mergeable(__rq))
-                q->last_merge = __rq;
-out_insert:
         if (ret) {
                 if (rq_mergeable(__rq))
                         as_hot_arq_hash(ad, RQ_DATA(__rq));
@@ -1693,9 +1549,6 @@ static void as_merged_request(request_queue_t *q, struct request *req)
                  * behind the disk head. We currently don't bother adjusting.
                  */
         }
-
-        if (arq->on_hash)
-                q->last_merge = req;
 }
 
 static void
@@ -1763,6 +1616,7 @@ as_merged_requests(request_queue_t *q, struct request *req,
          * kill knowledge of next, this one is a goner
          */
         as_remove_queued_request(q, next);
+        as_put_io_context(anext);
 
         anext->state = AS_RQ_MERGED;
 }
@@ -1782,7 +1636,7 @@ static void as_work_handler(void *data)
         unsigned long flags;
 
         spin_lock_irqsave(q->queue_lock, flags);
-        if (as_next_request(q))
+        if (!as_queue_empty(q))
                 q->request_fn(q);
         spin_unlock_irqrestore(q->queue_lock, flags);
 }
@@ -1797,7 +1651,9 @@ static void as_put_request(request_queue_t *q, struct request *rq)
                 return;
         }
 
-        if (arq->state != AS_RQ_POSTSCHED && arq->state != AS_RQ_PRESCHED) {
+        if (unlikely(arq->state != AS_RQ_POSTSCHED &&
+                     arq->state != AS_RQ_PRESCHED &&
+                     arq->state != AS_RQ_MERGED)) {
                 printk("arq->state %d\n", arq->state);
                 WARN_ON(1);
         }
@@ -1807,7 +1663,7 @@ static void as_put_request(request_queue_t *q, struct request *rq)
 }
 
 static int as_set_request(request_queue_t *q, struct request *rq,
-                          struct bio *bio, int gfp_mask)
+                          struct bio *bio, gfp_t gfp_mask)
 {
         struct as_data *ad = q->elevator->elevator_data;
         struct as_rq *arq = mempool_alloc(ad->arq_pool, gfp_mask);
@@ -1907,7 +1763,6 @@ static int as_init_queue(request_queue_t *q, elevator_t *e)
         INIT_LIST_HEAD(&ad->fifo_list[REQ_ASYNC]);
         ad->sort_list[REQ_SYNC] = RB_ROOT;
         ad->sort_list[REQ_ASYNC] = RB_ROOT;
-        ad->dispatch = &q->queue_head;
         ad->fifo_expire[REQ_SYNC] = default_read_expire;
         ad->fifo_expire[REQ_ASYNC] = default_write_expire;
         ad->antic_expire = default_antic_expire;
@@ -2072,10 +1927,9 @@ static struct elevator_type iosched_as = {
                 .elevator_merge_fn =            as_merge,
                 .elevator_merged_fn =           as_merged_request,
                 .elevator_merge_req_fn =        as_merged_requests,
-                .elevator_next_req_fn =         as_next_request,
-                .elevator_add_req_fn =          as_insert_request,
-                .elevator_remove_req_fn =       as_remove_request,
-                .elevator_requeue_req_fn =      as_requeue_request,
+                .elevator_dispatch_fn =         as_dispatch_request,
+                .elevator_add_req_fn =          as_add_request,
+                .elevator_activate_req_fn =     as_activate_request,
                 .elevator_deactivate_req_fn =   as_deactivate_request,
                 .elevator_queue_empty_fn =      as_queue_empty,
                 .elevator_completed_req_fn =    as_completed_request,
@@ -2119,8 +1973,8 @@ static int __init as_init(void)
 
 static void __exit as_exit(void)
 {
-        kmem_cache_destroy(arq_pool);
         elv_unregister(&iosched_as);
+        kmem_cache_destroy(arq_pool);
 }
 
 module_init(as_init);
diff --git a/drivers/block/cciss_scsi.c b/drivers/block/cciss_scsi.c
index e183a3ef7839..ec27976a57da 100644
--- a/drivers/block/cciss_scsi.c
+++ b/drivers/block/cciss_scsi.c
@@ -28,13 +28,17 @@
    through the array controller.  Note in particular, neither 
    physical nor logical disks are presented through the scsi layer. */
 
+#include <linux/timer.h>
+#include <linux/completion.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+
+#include <asm/atomic.h>
+
 #include <scsi/scsi.h> 
 #include <scsi/scsi_cmnd.h>
 #include <scsi/scsi_device.h>
 #include <scsi/scsi_host.h> 
-#include <asm/atomic.h>
-#include <linux/timer.h>
-#include <linux/completion.h>
 
 #include "cciss_scsi.h"
 
diff --git a/drivers/block/cfq-iosched.c b/drivers/block/cfq-iosched.c
index cd056e7e64ec..5281f8e70510 100644
--- a/drivers/block/cfq-iosched.c
+++ b/drivers/block/cfq-iosched.c
@@ -84,7 +84,6 @@ static int cfq_max_depth = 2;
         (node)->rb_left = NULL;         \
 } while (0)
 #define RB_CLEAR_ROOT(root)     ((root)->rb_node = NULL)
-#define ON_RB(node)             ((node)->rb_color != RB_NONE)
 #define rb_entry_crq(node)      rb_entry((node), struct cfq_rq, rb_node)
 #define rq_rb_key(rq)           (rq)->sector
 
@@ -271,10 +270,7 @@ CFQ_CFQQ_FNS(expired);
 #undef CFQ_CFQQ_FNS
 
 enum cfq_rq_state_flags {
-        CFQ_CRQ_FLAG_in_flight = 0,
-        CFQ_CRQ_FLAG_in_driver,
-        CFQ_CRQ_FLAG_is_sync,
-        CFQ_CRQ_FLAG_requeued,
+        CFQ_CRQ_FLAG_is_sync = 0,
 };
 
 #define CFQ_CRQ_FNS(name)                                               \
@@ -291,14 +287,11 @@ static inline int cfq_crq_##name(const struct cfq_rq *crq)		\
         return (crq->crq_flags & (1 << CFQ_CRQ_FLAG_##name)) != 0;      \
 }
 
-CFQ_CRQ_FNS(in_flight);
-CFQ_CRQ_FNS(in_driver);
 CFQ_CRQ_FNS(is_sync);
-CFQ_CRQ_FNS(requeued);
 #undef CFQ_CRQ_FNS
 
 static struct cfq_queue *cfq_find_cfq_hash(struct cfq_data *, unsigned int, unsigned short);
-static void cfq_dispatch_sort(request_queue_t *, struct cfq_rq *);
+static void cfq_dispatch_insert(request_queue_t *, struct cfq_rq *);
 static void cfq_put_cfqd(struct cfq_data *cfqd);
 
 #define process_sync(tsk)       ((tsk)->flags & PF_SYNCWRITE)
@@ -311,14 +304,6 @@ static inline void cfq_del_crq_hash(struct cfq_rq *crq)
         hlist_del_init(&crq->hash);
 }
 
-static void cfq_remove_merge_hints(request_queue_t *q, struct cfq_rq *crq)
-{
-        cfq_del_crq_hash(crq);
-
-        if (q->last_merge == crq->request)
-                q->last_merge = NULL;
-}
-
 static inline void cfq_add_crq_hash(struct cfq_data *cfqd, struct cfq_rq *crq)
 {
         const int hash_idx = CFQ_MHASH_FN(rq_hash_key(crq->request));
@@ -347,18 +332,13 @@ static struct request *cfq_find_rq_hash(struct cfq_data *cfqd, sector_t offset)
         return NULL;
 }
 
-static inline int cfq_pending_requests(struct cfq_data *cfqd)
-{
-        return !list_empty(&cfqd->queue->queue_head) || cfqd->busy_queues;
-}
-
 /*
  * scheduler run of queue, if there are requests pending and no one in the
  * driver that will restart queueing
  */
 static inline void cfq_schedule_dispatch(struct cfq_data *cfqd)
 {
-        if (!cfqd->rq_in_driver && cfq_pending_requests(cfqd))
+        if (!cfqd->rq_in_driver && cfqd->busy_queues)
                 kblockd_schedule_work(&cfqd->unplug_work);
 }
 
@@ -366,7 +346,7 @@ static int cfq_queue_empty(request_queue_t *q)
 {
         struct cfq_data *cfqd = q->elevator->elevator_data;
 
-        return !cfq_pending_requests(cfqd);
+        return !cfqd->busy_queues;
 }
 
 /*
@@ -386,11 +366,6 @@ cfq_choose_req(struct cfq_data *cfqd, struct cfq_rq *crq1, struct cfq_rq *crq2)
         if (crq2 == NULL)
                 return crq1;
 
-        if (cfq_crq_requeued(crq1) && !cfq_crq_requeued(crq2))
-                return crq1;
-        else if (cfq_crq_requeued(crq2) && !cfq_crq_requeued(crq1))
-                return crq2;
-
         if (cfq_crq_is_sync(crq1) && !cfq_crq_is_sync(crq2))
                 return crq1;
         else if (cfq_crq_is_sync(crq2) && !cfq_crq_is_sync(crq1))
@@ -461,10 +436,7 @@ cfq_find_next_crq(struct cfq_data *cfqd, struct cfq_queue *cfqq,
         struct cfq_rq *crq_next = NULL, *crq_prev = NULL;
         struct rb_node *rbnext, *rbprev;
 
-        rbnext = NULL;
-        if (ON_RB(&last->rb_node))
-                rbnext = rb_next(&last->rb_node);
-        if (!rbnext) {
+        if (!(rbnext = rb_next(&last->rb_node))) {
                 rbnext = rb_first(&cfqq->sort_list);
                 if (rbnext == &last->rb_node)
                         rbnext = NULL;
@@ -545,13 +517,13 @@ static void cfq_resort_rr_list(struct cfq_queue *cfqq, int preempted)
  * the pending list according to last request service
  */
 static inline void
-cfq_add_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq, int requeue)
+cfq_add_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq)
 {
         BUG_ON(cfq_cfqq_on_rr(cfqq));
         cfq_mark_cfqq_on_rr(cfqq);
         cfqd->busy_queues++;
 
-        cfq_resort_rr_list(cfqq, requeue);
+        cfq_resort_rr_list(cfqq, 0);
 }
 
 static inline void
@@ -571,22 +543,19 @@ cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq)
 static inline void cfq_del_crq_rb(struct cfq_rq *crq)
 {
         struct cfq_queue *cfqq = crq->cfq_queue;
+        struct cfq_data *cfqd = cfqq->cfqd;
+        const int sync = cfq_crq_is_sync(crq);
 
-        if (ON_RB(&crq->rb_node)) {
-                struct cfq_data *cfqd = cfqq->cfqd;
-                const int sync = cfq_crq_is_sync(crq);
-
-                BUG_ON(!cfqq->queued[sync]);
-                cfqq->queued[sync]--;
+        BUG_ON(!cfqq->queued[sync]);
+        cfqq->queued[sync]--;
 
-                cfq_update_next_crq(crq);
+        cfq_update_next_crq(crq);
 
-                rb_erase(&crq->rb_node, &cfqq->sort_list);
-                RB_CLEAR_COLOR(&crq->rb_node);
+        rb_erase(&crq->rb_node, &cfqq->sort_list);
+        RB_CLEAR_COLOR(&crq->rb_node);
 
-                if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY(&cfqq->sort_list))
-                        cfq_del_cfqq_rr(cfqd, cfqq);
-        }
+        if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY(&cfqq->sort_list))
+                cfq_del_cfqq_rr(cfqd, cfqq);
 }
 
 static struct cfq_rq *
@@ -627,12 +596,12 @@ static void cfq_add_crq_rb(struct cfq_rq *crq)
          * if that happens, put the alias on the dispatch list
          */
         while ((__alias = __cfq_add_crq_rb(crq)) != NULL)
-                cfq_dispatch_sort(cfqd->queue, __alias);
+                cfq_dispatch_insert(cfqd->queue, __alias);
 
         rb_insert_color(&crq->rb_node, &cfqq->sort_list);
 
         if (!cfq_cfqq_on_rr(cfqq))
-                cfq_add_cfqq_rr(cfqd, cfqq, cfq_crq_requeued(crq));
+                cfq_add_cfqq_rr(cfqd, cfqq);
 
         /*
          * check if this request is a better next-serve candidate
@@ -643,10 +612,8 @@ static void cfq_add_crq_rb(struct cfq_rq *crq)
 static inline void
 cfq_reposition_crq_rb(struct cfq_queue *cfqq, struct cfq_rq *crq)
 {
-        if (ON_RB(&crq->rb_node)) {
-                rb_erase(&crq->rb_node, &cfqq->sort_list);
-                cfqq->queued[cfq_crq_is_sync(crq)]--;
-        }
+        rb_erase(&crq->rb_node, &cfqq->sort_list);
+        cfqq->queued[cfq_crq_is_sync(crq)]--;
 
         cfq_add_crq_rb(crq);
 }
@@ -676,49 +643,28 @@ out:
         return NULL;
 }
 
-static void cfq_deactivate_request(request_queue_t *q, struct request *rq)
+static void cfq_activate_request(request_queue_t *q, struct request *rq)
 {
         struct cfq_data *cfqd = q->elevator->elevator_data;
-        struct cfq_rq *crq = RQ_DATA(rq);
-
-        if (crq) {
-                struct cfq_queue *cfqq = crq->cfq_queue;
 
-                if (cfq_crq_in_driver(crq)) {
-                        cfq_clear_crq_in_driver(crq);
-                        WARN_ON(!cfqd->rq_in_driver);
-                        cfqd->rq_in_driver--;
-                }
-                if (cfq_crq_in_flight(crq)) {
-                        const int sync = cfq_crq_is_sync(crq);
-
-                        cfq_clear_crq_in_flight(crq);
-                        WARN_ON(!cfqq->on_dispatch[sync]);
-                        cfqq->on_dispatch[sync]--;
-                }
-                cfq_mark_crq_requeued(crq);
-        }
+        cfqd->rq_in_driver++;
 }
 
-/*
- * make sure the service time gets corrected on reissue of this request
- */
-static void cfq_requeue_request(request_queue_t *q, struct request *rq)
+static void cfq_deactivate_request(request_queue_t *q, struct request *rq)
 {
-        cfq_deactivate_request(q, rq);
-        list_add(&rq->queuelist, &q->queue_head);
+        struct cfq_data *cfqd = q->elevator->elevator_data;
+
+        WARN_ON(!cfqd->rq_in_driver);
+        cfqd->rq_in_driver--;
 }
 
-static void cfq_remove_request(request_queue_t *q, struct request *rq)
+static void cfq_remove_request(struct request *rq)
 {
         struct cfq_rq *crq = RQ_DATA(rq);
 
-        if (crq) {
-                list_del_init(&rq->queuelist);
-                cfq_del_crq_rb(crq);
-                cfq_remove_merge_hints(q, crq);
-
-        }
+        list_del_init(&rq->queuelist);
+        cfq_del_crq_rb(crq);
+        cfq_del_crq_hash(crq);
 }
 
 static int
@@ -728,12 +674,6 @@ cfq_merge(request_queue_t *q, struct request **req, struct bio *bio)
         struct request *__rq;
         int ret;
 
-        ret = elv_try_last_merge(q, bio);
-        if (ret != ELEVATOR_NO_MERGE) {
-                __rq = q->last_merge;
-                goto out_insert;
-        }
-
         __rq = cfq_find_rq_hash(cfqd, bio->bi_sector);
         if (__rq && elv_rq_merge_ok(__rq, bio)) {
                 ret = ELEVATOR_BACK_MERGE;
@@ -748,8 +688,6 @@ cfq_merge(request_queue_t *q, struct request **req, struct bio *bio)
 
         return ELEVATOR_NO_MERGE;
 out:
-        q->last_merge = __rq;
-out_insert:
         *req = __rq;
         return ret;
 }
@@ -762,14 +700,12 @@ static void cfq_merged_request(request_queue_t *q, struct request *req)
         cfq_del_crq_hash(crq);
         cfq_add_crq_hash(cfqd, crq);
 
-        if (ON_RB(&crq->rb_node) && (rq_rb_key(req) != crq->rb_key)) {
+        if (rq_rb_key(req) != crq->rb_key) {
                 struct cfq_queue *cfqq = crq->cfq_queue;
 
                 cfq_update_next_crq(crq);
                 cfq_reposition_crq_rb(cfqq, crq);
         }
-
-        q->last_merge = req;
 }
 
 static void
@@ -785,7 +721,7 @@ cfq_merged_requests(request_queue_t *q, struct request *rq,
             time_before(next->start_time, rq->start_time))
                 list_move(&rq->queuelist, &next->queuelist);
 
-        cfq_remove_request(q, next);
+        cfq_remove_request(next);
 }
 
 static inline void
@@ -992,53 +928,15 @@ static int cfq_arm_slice_timer(struct cfq_data *cfqd, struct cfq_queue *cfqq)
         return 1;
 }
 
-/*
- * we dispatch cfqd->cfq_quantum requests in total from the rr_list queues,
- * this function sector sorts the selected request to minimize seeks. we start
- * at cfqd->last_sector, not 0.
- */
-static void cfq_dispatch_sort(request_queue_t *q, struct cfq_rq *crq)
+static void cfq_dispatch_insert(request_queue_t *q, struct cfq_rq *crq)
 {
         struct cfq_data *cfqd = q->elevator->elevator_data;
         struct cfq_queue *cfqq = crq->cfq_queue;
-        struct list_head *head = &q->queue_head, *entry = head;
-        struct request *__rq;
-        sector_t last;
-
-        list_del(&crq->request->queuelist);
-
-        last = cfqd->last_sector;
-        list_for_each_entry_reverse(__rq, head, queuelist) {
-                struct cfq_rq *__crq = RQ_DATA(__rq);
-
-                if (blk_barrier_rq(__rq))
-                        break;
-                if (!blk_fs_request(__rq))
-                        break;
-                if (cfq_crq_requeued(__crq))
-                        break;
-
-                if (__rq->sector <= crq->request->sector)
-                        break;
-                if (__rq->sector > last && crq->request->sector < last) {
-                        last = crq->request->sector + crq->request->nr_sectors;
-                        break;
-                }
-                entry = &__rq->queuelist;
-        }
-
-        cfqd->last_sector = last;
 
         cfqq->next_crq = cfq_find_next_crq(cfqd, cfqq, crq);
-
-        cfq_del_crq_rb(crq);
-        cfq_remove_merge_hints(q, crq);
-
-        cfq_mark_crq_in_flight(crq);
-        cfq_clear_crq_requeued(crq);
-
+        cfq_remove_request(crq->request);
         cfqq->on_dispatch[cfq_crq_is_sync(crq)]++;
-        list_add_tail(&crq->request->queuelist, entry);
+        elv_dispatch_sort(q, crq->request);
 }
 
 /*
@@ -1159,7 +1057,7 @@ __cfq_dispatch_requests(struct cfq_data *cfqd, struct cfq_queue *cfqq,
                 /*
                  * finally, insert request into driver dispatch list
                  */
-                cfq_dispatch_sort(cfqd->queue, crq);
+                cfq_dispatch_insert(cfqd->queue, crq);
 
                 cfqd->dispatch_slice++;
                 dispatched++;
@@ -1194,7 +1092,7 @@ __cfq_dispatch_requests(struct cfq_data *cfqd, struct cfq_queue *cfqq,
 }
 
 static int
-cfq_dispatch_requests(request_queue_t *q, int max_dispatch, int force)
+cfq_dispatch_requests(request_queue_t *q, int force)
 {
         struct cfq_data *cfqd = q->elevator->elevator_data;
         struct cfq_queue *cfqq;
@@ -1204,12 +1102,25 @@ cfq_dispatch_requests(request_queue_t *q, int max_dispatch, int force)
 
         cfqq = cfq_select_queue(cfqd, force);
         if (cfqq) {
+                int max_dispatch;
+
+                /*
+                 * if idle window is disabled, allow queue buildup
+                 */
+                if (!cfq_cfqq_idle_window(cfqq) &&
+                    cfqd->rq_in_driver >= cfqd->cfq_max_depth)
+                        return 0;
+
                 cfq_clear_cfqq_must_dispatch(cfqq);
                 cfq_clear_cfqq_wait_request(cfqq);
                 del_timer(&cfqd->idle_slice_timer);
 
-                if (cfq_class_idle(cfqq))
-                        max_dispatch = 1;
+                if (!force) {
+                        max_dispatch = cfqd->cfq_quantum;
+                        if (cfq_class_idle(cfqq))
+                                max_dispatch = 1;
+                } else
+                        max_dispatch = INT_MAX;
 
                 return __cfq_dispatch_requests(cfqd, cfqq, max_dispatch);
         }
@@ -1217,93 +1128,6 @@ cfq_dispatch_requests(request_queue_t *q, int max_dispatch, int force)
         return 0;
 }
 
-static inline void cfq_account_dispatch(struct cfq_rq *crq)
-{
-        struct cfq_queue *cfqq = crq->cfq_queue;
-        struct cfq_data *cfqd = cfqq->cfqd;
-
-        if (unlikely(!blk_fs_request(crq->request)))
-                return;
-
-        /*
-         * accounted bit is necessary since some drivers will call
-         * elv_next_request() many times for the same request (eg ide)
-         */
-        if (cfq_crq_in_driver(crq))
-                return;
-
-        cfq_mark_crq_in_driver(crq);
-        cfqd->rq_in_driver++;
-}
-
-static inline void
-cfq_account_completion(struct cfq_queue *cfqq, struct cfq_rq *crq)
-{
-        struct cfq_data *cfqd = cfqq->cfqd;
-        unsigned long now;
-
-        if (!cfq_crq_in_driver(crq))
-                return;
-
-        now = jiffies;
-
-        WARN_ON(!cfqd->rq_in_driver);
-        cfqd->rq_in_driver--;
-
-        if (!cfq_class_idle(cfqq))
-                cfqd->last_end_request = now;
-
-        if (!cfq_cfqq_dispatched(cfqq)) {
-                if (cfq_cfqq_on_rr(cfqq)) {
-                        cfqq->service_last = now;
-                        cfq_resort_rr_list(cfqq, 0);
-                }
-                if (cfq_cfqq_expired(cfqq)) {
-                        __cfq_slice_expired(cfqd, cfqq, 0);
-                        cfq_schedule_dispatch(cfqd);
-                }
-        }
-
-        if (cfq_crq_is_sync(crq))
-                crq->io_context->last_end_request = now;
-}
-
-static struct request *cfq_next_request(request_queue_t *q)
-{
-        struct cfq_data *cfqd = q->elevator->elevator_data;
-        struct request *rq;
-
-        if (!list_empty(&q->queue_head)) {
-                struct cfq_rq *crq;
-dispatch:
-                rq = list_entry_rq(q->queue_head.next);
-
-                crq = RQ_DATA(rq);
-                if (crq) {
-                        struct cfq_queue *cfqq = crq->cfq_queue;
-
-                        /*
-                         * if idle window is disabled, allow queue buildup
-                         */
-                        if (!cfq_crq_in_driver(crq) &&
-                            !cfq_cfqq_idle_window(cfqq) &&
-                            !blk_barrier_rq(rq) &&
-                            cfqd->rq_in_driver >= cfqd->cfq_max_depth)
-                                return NULL;
-
-                        cfq_remove_merge_hints(q, crq);
-                        cfq_account_dispatch(crq);
-                }
-
-                return rq;
-        }
-
-        if (cfq_dispatch_requests(q, cfqd->cfq_quantum, 0))
-                goto dispatch;
-
-        return NULL;
-}
-
 /*
  * task holds one reference to the queue, dropped when task exits. each crq
  * in-flight on this queue also holds a reference, dropped when crq is freed.
@@ -1422,7 +1246,7 @@ static void cfq_exit_io_context(struct cfq_io_context *cic)
 }
 
 static struct cfq_io_context *
-cfq_alloc_io_context(struct cfq_data *cfqd, int gfp_mask)
+cfq_alloc_io_context(struct cfq_data *cfqd, gfp_t gfp_mask)
 {
         struct cfq_io_context *cic = kmem_cache_alloc(cfq_ioc_pool, gfp_mask);
 
@@ -1517,7 +1341,7 @@ static int cfq_ioc_set_ioprio(struct io_context *ioc, unsigned int ioprio)
 
 static struct cfq_queue *
 cfq_get_queue(struct cfq_data *cfqd, unsigned int key, unsigned short ioprio,
-              int gfp_mask)
+              gfp_t gfp_mask)
 {
         const int hashval = hash_long(key, CFQ_QHASH_SHIFT);
         struct cfq_queue *cfqq, *new_cfqq = NULL;
@@ -1578,7 +1402,7 @@ out:
  * cfqq, so we don't need to worry about it disappearing
  */
 static struct cfq_io_context *
-cfq_get_io_context(struct cfq_data *cfqd, pid_t pid, int gfp_mask)
+cfq_get_io_context(struct cfq_data *cfqd, pid_t pid, gfp_t gfp_mask)
 {
         struct io_context *ioc = NULL;
         struct cfq_io_context *cic;
@@ -1816,8 +1640,9 @@ cfq_crq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq,
         }
 }
 
-static void cfq_enqueue(struct cfq_data *cfqd, struct request *rq)
+static void cfq_insert_request(request_queue_t *q, struct request *rq)
 {
+        struct cfq_data *cfqd = q->elevator->elevator_data;
         struct cfq_rq *crq = RQ_DATA(rq);
         struct cfq_queue *cfqq = crq->cfq_queue;
 
@@ -1827,66 +1652,43 @@ static void cfq_enqueue(struct cfq_data *cfqd, struct request *rq)
 
         list_add_tail(&rq->queuelist, &cfqq->fifo);
 
-        if (rq_mergeable(rq)) {
+        if (rq_mergeable(rq))
                 cfq_add_crq_hash(cfqd, crq);
 
-                if (!cfqd->queue->last_merge)
-                        cfqd->queue->last_merge = rq;
-        }
-
         cfq_crq_enqueued(cfqd, cfqq, crq);
 }
 
-static void
-cfq_insert_request(request_queue_t *q, struct request *rq, int where)
-{
-        struct cfq_data *cfqd = q->elevator->elevator_data;
-
-        switch (where) {
-                case ELEVATOR_INSERT_BACK:
-                        while (cfq_dispatch_requests(q, INT_MAX, 1))
-                                ;
-                        list_add_tail(&rq->queuelist, &q->queue_head);
-                        /*
-                         * If we were idling with pending requests on
-                         * inactive cfqqs, force dispatching will
-                         * remove the idle timer and the queue won't
-                         * be kicked by __make_request() afterward.
-                         * Kick it here.
-                         */
-                        cfq_schedule_dispatch(cfqd);
-                        break;
-                case ELEVATOR_INSERT_FRONT:
-                        list_add(&rq->queuelist, &q->queue_head);
-                        break;
-                case ELEVATOR_INSERT_SORT:
-                        BUG_ON(!blk_fs_request(rq));
-                        cfq_enqueue(cfqd, rq);
-                        break;
-                default:
-                        printk("%s: bad insert point %d\n", __FUNCTION__,where);
-                        return;
-        }
-}
-
 static void cfq_completed_request(request_queue_t *q, struct request *rq)
 {
         struct cfq_rq *crq = RQ_DATA(rq);
-        struct cfq_queue *cfqq;
+        struct cfq_queue *cfqq = crq->cfq_queue;
+        struct cfq_data *cfqd = cfqq->cfqd;
+        const int sync = cfq_crq_is_sync(crq);
+        unsigned long now;
 
-        if (unlikely(!blk_fs_request(rq)))
-                return;
+        now = jiffies;
 
-        cfqq = crq->cfq_queue;
+        WARN_ON(!cfqd->rq_in_driver);
+        WARN_ON(!cfqq->on_dispatch[sync]);
+        cfqd->rq_in_driver--;
+        cfqq->on_dispatch[sync]--;
 
-        if (cfq_crq_in_flight(crq)) {
-                const int sync = cfq_crq_is_sync(crq);
+        if (!cfq_class_idle(cfqq))
+                cfqd->last_end_request = now;
 
-                WARN_ON(!cfqq->on_dispatch[sync]);
-                cfqq->on_dispatch[sync]--;
+        if (!cfq_cfqq_dispatched(cfqq)) {
+                if (cfq_cfqq_on_rr(cfqq)) {
+                        cfqq->service_last = now;
+                        cfq_resort_rr_list(cfqq, 0);
+                }
+                if (cfq_cfqq_expired(cfqq)) {
+                        __cfq_slice_expired(cfqd, cfqq, 0);
+                        cfq_schedule_dispatch(cfqd);
+                }
         }
 
-        cfq_account_completion(cfqq, crq);
+        if (cfq_crq_is_sync(crq))
+                crq->io_context->last_end_request = now;
 }
 
 static struct request *
@@ -2075,7 +1877,7 @@ static void cfq_put_request(request_queue_t *q, struct request *rq)
  */
 static int
 cfq_set_request(request_queue_t *q, struct request *rq, struct bio *bio,
-                int gfp_mask)
+                gfp_t gfp_mask)
 {
         struct cfq_data *cfqd = q->elevator->elevator_data;
         struct task_struct *tsk = current;
@@ -2118,9 +1920,6 @@ cfq_set_request(request_queue_t *q, struct request *rq, struct bio *bio,
                 INIT_HLIST_NODE(&crq->hash);
                 crq->cfq_queue = cfqq;
                 crq->io_context = cic;
-                cfq_clear_crq_in_flight(crq);
-                cfq_clear_crq_in_driver(crq);
-                cfq_clear_crq_requeued(crq);
 
                 if (rw == READ || process_sync(tsk))
                         cfq_mark_crq_is_sync(crq);
@@ -2201,7 +2000,7 @@ static void cfq_idle_slice_timer(unsigned long data)
                  * only expire and reinvoke request handler, if there are
                  * other queues with pending requests
                  */
-                if (!cfq_pending_requests(cfqd)) {
+                if (!cfqd->busy_queues) {
                         cfqd->idle_slice_timer.expires = min(now + cfqd->cfq_slice_idle, cfqq->slice_end);
                         add_timer(&cfqd->idle_slice_timer);
                         goto out_cont;
@@ -2576,10 +2375,9 @@ static struct elevator_type iosched_cfq = {
                 .elevator_merge_fn =            cfq_merge,
                 .elevator_merged_fn =           cfq_merged_request,
                 .elevator_merge_req_fn =        cfq_merged_requests,
-                .elevator_next_req_fn =         cfq_next_request,
+                .elevator_dispatch_fn =         cfq_dispatch_requests,
                 .elevator_add_req_fn =          cfq_insert_request,
-                .elevator_remove_req_fn =       cfq_remove_request,
-                .elevator_requeue_req_fn =      cfq_requeue_request,
+                .elevator_activate_req_fn =     cfq_activate_request,
                 .elevator_deactivate_req_fn =   cfq_deactivate_request,
                 .elevator_queue_empty_fn =      cfq_queue_empty,
                 .elevator_completed_req_fn =    cfq_completed_request,
@@ -2620,28 +2418,8 @@ static int __init cfq_init(void)
 
 static void __exit cfq_exit(void)
 {
-        struct task_struct *g, *p;
-        unsigned long flags;
-
-        read_lock_irqsave(&tasklist_lock, flags);
-
-        /*
-         * iterate each process in the system, removing our io_context
-         */
-        do_each_thread(g, p) {
-                struct io_context *ioc = p->io_context;
-
-                if (ioc && ioc->cic) {
-                        ioc->cic->exit(ioc->cic);
-                        cfq_free_io_context(ioc->cic);
-                        ioc->cic = NULL;
-                }
-        } while_each_thread(g, p);
-
-        read_unlock_irqrestore(&tasklist_lock, flags);
-
-        cfq_slab_kill();
         elv_unregister(&iosched_cfq);
+        cfq_slab_kill();
 }
 
 module_init(cfq_init);
diff --git a/drivers/block/deadline-iosched.c b/drivers/block/deadline-iosched.c
index 52a3ae5289a0..7929471d7df7 100644
--- a/drivers/block/deadline-iosched.c
+++ b/drivers/block/deadline-iosched.c
@@ -50,7 +50,6 @@ struct deadline_data {
          * next in sort order. read, write or both are NULL
          */
         struct deadline_rq *next_drq[2];
-        struct list_head *dispatch;     /* driver dispatch queue */
         struct list_head *hash;         /* request hash */
         unsigned int batching;          /* number of sequential requests made */
         sector_t last_sector;           /* head position */
@@ -113,15 +112,6 @@ static inline void deadline_del_drq_hash(struct deadline_rq *drq)
                 __deadline_del_drq_hash(drq);
 }
 
-static void
-deadline_remove_merge_hints(request_queue_t *q, struct deadline_rq *drq)
-{
-        deadline_del_drq_hash(drq);
-
-        if (q->last_merge == drq->request)
-                q->last_merge = NULL;
-}
-
 static inline void
 deadline_add_drq_hash(struct deadline_data *dd, struct deadline_rq *drq)
 {
@@ -239,10 +229,9 @@ deadline_del_drq_rb(struct deadline_data *dd, struct deadline_rq *drq)
                         dd->next_drq[data_dir] = rb_entry_drq(rbnext);
         }
 
-        if (ON_RB(&drq->rb_node)) {
-                rb_erase(&drq->rb_node, DRQ_RB_ROOT(dd, drq));
-                RB_CLEAR(&drq->rb_node);
-        }
+        BUG_ON(!ON_RB(&drq->rb_node));
+        rb_erase(&drq->rb_node, DRQ_RB_ROOT(dd, drq));
+        RB_CLEAR(&drq->rb_node);
 }
 
 static struct request *
@@ -286,7 +275,7 @@ deadline_find_first_drq(struct deadline_data *dd, int data_dir)
 /*
  * add drq to rbtree and fifo
  */
-static inline void
+static void
 deadline_add_request(struct request_queue *q, struct request *rq)
 {
         struct deadline_data *dd = q->elevator->elevator_data;
@@ -301,12 +290,8 @@ deadline_add_request(struct request_queue *q, struct request *rq)
         drq->expires = jiffies + dd->fifo_expire[data_dir];
         list_add_tail(&drq->fifo, &dd->fifo_list[data_dir]);
 
-        if (rq_mergeable(rq)) {
+        if (rq_mergeable(rq))
                 deadline_add_drq_hash(dd, drq);
-
-                if (!q->last_merge)
-                        q->last_merge = rq;
-        }
 }
 
 /*
@@ -315,14 +300,11 @@ deadline_add_request(struct request_queue *q, struct request *rq)
 static void deadline_remove_request(request_queue_t *q, struct request *rq)
 {
         struct deadline_rq *drq = RQ_DATA(rq);
+        struct deadline_data *dd = q->elevator->elevator_data;
 
-        if (drq) {
-                struct deadline_data *dd = q->elevator->elevator_data;
-
-                list_del_init(&drq->fifo);
-                deadline_remove_merge_hints(q, drq);
-                deadline_del_drq_rb(dd, drq);
-        }
+        list_del_init(&drq->fifo);
+        deadline_del_drq_rb(dd, drq);
+        deadline_del_drq_hash(drq);
 }
 
 static int
@@ -333,15 +315,6 @@ deadline_merge(request_queue_t *q, struct request **req, struct bio *bio)
         int ret;
 
         /*
-         * try last_merge to avoid going to hash
-         */
-        ret = elv_try_last_merge(q, bio);
-        if (ret != ELEVATOR_NO_MERGE) {
-                __rq = q->last_merge;
-                goto out_insert;
-        }
-
-        /*
          * see if the merge hash can satisfy a back merge
          */
         __rq = deadline_find_drq_hash(dd, bio->bi_sector);
@@ -373,8 +346,6 @@ deadline_merge(request_queue_t *q, struct request **req, struct bio *bio)
 
         return ELEVATOR_NO_MERGE;
 out:
-        q->last_merge = __rq;
-out_insert:
         if (ret)
                 deadline_hot_drq_hash(dd, RQ_DATA(__rq));
         *req = __rq;
@@ -399,8 +370,6 @@ static void deadline_merged_request(request_queue_t *q, struct request *req)
                 deadline_del_drq_rb(dd, drq);
                 deadline_add_drq_rb(dd, drq);
         }
-
-        q->last_merge = req;
 }
 
 static void
@@ -452,7 +421,7 @@ deadline_move_to_dispatch(struct deadline_data *dd, struct deadline_rq *drq)
         request_queue_t *q = drq->request->q;
 
         deadline_remove_request(q, drq->request);
-        list_add_tail(&drq->request->queuelist, dd->dispatch);
+        elv_dispatch_add_tail(q, drq->request);
 }
 
 /*
@@ -502,8 +471,9 @@ static inline int deadline_check_fifo(struct deadline_data *dd, int ddir)
  * deadline_dispatch_requests selects the best request according to
  * read/write expire, fifo_batch, etc
  */
-static int deadline_dispatch_requests(struct deadline_data *dd)
+static int deadline_dispatch_requests(request_queue_t *q, int force)
 {
+        struct deadline_data *dd = q->elevator->elevator_data;
         const int reads = !list_empty(&dd->fifo_list[READ]);
         const int writes = !list_empty(&dd->fifo_list[WRITE]);
         struct deadline_rq *drq;
@@ -597,65 +567,12 @@ dispatch_request:
         return 1;
 }
 
-static struct request *deadline_next_request(request_queue_t *q)
-{
-        struct deadline_data *dd = q->elevator->elevator_data;
-        struct request *rq;
-
-        /*
-         * if there are still requests on the dispatch queue, grab the first one
-         */
-        if (!list_empty(dd->dispatch)) {
-dispatch:
-                rq = list_entry_rq(dd->dispatch->next);
-                return rq;
-        }
-
-        if (deadline_dispatch_requests(dd))
-                goto dispatch;
-
-        return NULL;
-}
-
-static void
-deadline_insert_request(request_queue_t *q, struct request *rq, int where)
-{
-        struct deadline_data *dd = q->elevator->elevator_data;
-
-        /* barriers must flush the reorder queue */
-        if (unlikely(rq->flags & (REQ_SOFTBARRIER | REQ_HARDBARRIER)
-                        && where == ELEVATOR_INSERT_SORT))
-                where = ELEVATOR_INSERT_BACK;
-
-        switch (where) {
-                case ELEVATOR_INSERT_BACK:
-                        while (deadline_dispatch_requests(dd))
-                                ;
-                        list_add_tail(&rq->queuelist, dd->dispatch);
-                        break;
-                case ELEVATOR_INSERT_FRONT:
-                        list_add(&rq->queuelist, dd->dispatch);
-                        break;
-                case ELEVATOR_INSERT_SORT:
-                        BUG_ON(!blk_fs_request(rq));
-                        deadline_add_request(q, rq);
-                        break;
-                default:
-                        printk("%s: bad insert point %d\n", __FUNCTION__,where);
-                        return;
-        }
-}
-
 static int deadline_queue_empty(request_queue_t *q)
 {
         struct deadline_data *dd = q->elevator->elevator_data;
 
-        if (!list_empty(&dd->fifo_list[WRITE])
-            || !list_empty(&dd->fifo_list[READ])
-            || !list_empty(dd->dispatch))
-                return 0;
-
-        return 1;
+        return list_empty(&dd->fifo_list[WRITE])
+                && list_empty(&dd->fifo_list[READ]);
 }
 
 static struct request *
@@ -733,7 +650,6 @@ static int deadline_init_queue(request_queue_t *q, elevator_t *e)
         INIT_LIST_HEAD(&dd->fifo_list[WRITE]);
         dd->sort_list[READ] = RB_ROOT;
         dd->sort_list[WRITE] = RB_ROOT;
-        dd->dispatch = &q->queue_head;
         dd->fifo_expire[READ] = read_expire;
         dd->fifo_expire[WRITE] = write_expire;
         dd->writes_starved = writes_starved;
@@ -748,15 +664,13 @@ static void deadline_put_request(request_queue_t *q, struct request *rq)
         struct deadline_data *dd = q->elevator->elevator_data;
         struct deadline_rq *drq = RQ_DATA(rq);
 
-        if (drq) {
-                mempool_free(drq, dd->drq_pool);
-                rq->elevator_private = NULL;
-        }
+        mempool_free(drq, dd->drq_pool);
+        rq->elevator_private = NULL;
 }
 
 static int
 deadline_set_request(request_queue_t *q, struct request *rq, struct bio *bio,
-                     int gfp_mask)
+                     gfp_t gfp_mask)
 {
         struct deadline_data *dd = q->elevator->elevator_data;
         struct deadline_rq *drq;
@@ -917,9 +831,8 @@ static struct elevator_type iosched_deadline = {
                 .elevator_merge_fn =            deadline_merge,
                 .elevator_merged_fn =           deadline_merged_request,
                 .elevator_merge_req_fn =        deadline_merged_requests,
-                .elevator_next_req_fn =         deadline_next_request,
-                .elevator_add_req_fn =          deadline_insert_request,
-                .elevator_remove_req_fn =       deadline_remove_request,
+                .elevator_dispatch_fn =         deadline_dispatch_requests,
+                .elevator_add_req_fn =          deadline_add_request,
                 .elevator_queue_empty_fn =      deadline_queue_empty,
                 .elevator_former_req_fn =       deadline_former_request,
                 .elevator_latter_req_fn =       deadline_latter_request,
diff --git a/drivers/block/elevator.c b/drivers/block/elevator.c
index 98f0126a2deb..36f1057084b0 100644
--- a/drivers/block/elevator.c
+++ b/drivers/block/elevator.c
@@ -34,6 +34,7 @@
 #include <linux/slab.h>
 #include <linux/init.h>
 #include <linux/compiler.h>
+#include <linux/delay.h>
 
 #include <asm/uaccess.h>
 
@@ -83,21 +84,11 @@ inline int elv_try_merge(struct request *__rq, struct bio *bio)
 }
 EXPORT_SYMBOL(elv_try_merge);
 
-inline int elv_try_last_merge(request_queue_t *q, struct bio *bio)
-{
-        if (q->last_merge)
-                return elv_try_merge(q->last_merge, bio);
-
-        return ELEVATOR_NO_MERGE;
-}
-EXPORT_SYMBOL(elv_try_last_merge);
-
 static struct elevator_type *elevator_find(const char *name)
 {
         struct elevator_type *e = NULL;
         struct list_head *entry;
 
-        spin_lock_irq(&elv_list_lock);
         list_for_each(entry, &elv_list) {
                 struct elevator_type *__e;
 
@@ -108,7 +99,6 @@ static struct elevator_type *elevator_find(const char *name)
                         break;
                 }
         }
-        spin_unlock_irq(&elv_list_lock);
 
         return e;
 }
@@ -120,12 +110,15 @@ static void elevator_put(struct elevator_type *e)
 
 static struct elevator_type *elevator_get(const char *name)
 {
-        struct elevator_type *e = elevator_find(name);
+        struct elevator_type *e;
 
-        if (!e)
-                return NULL;
-        if (!try_module_get(e->elevator_owner))
-                return NULL;
+        spin_lock_irq(&elv_list_lock);
+
+        e = elevator_find(name);
+        if (e && !try_module_get(e->elevator_owner))
+                e = NULL;
+
+        spin_unlock_irq(&elv_list_lock);
 
         return e;
 }
@@ -139,8 +132,6 @@ static int elevator_attach(request_queue_t *q, struct elevator_type *e,
         eq->ops = &e->ops;
         eq->elevator_type = e;
 
-        INIT_LIST_HEAD(&q->queue_head);
-        q->last_merge = NULL;
         q->elevator = eq;
 
         if (eq->ops->elevator_init_fn)
@@ -153,23 +144,20 @@ static char chosen_elevator[16];
 
 static void elevator_setup_default(void)
 {
+        struct elevator_type *e;
+
         /*
-         * check if default is set and exists
+         * If default has not been set, use the compiled-in selection.
          */
-        if (chosen_elevator[0] && elevator_find(chosen_elevator))
-                return;
-
-#if defined(CONFIG_IOSCHED_AS)
-        strcpy(chosen_elevator, "anticipatory");
-#elif defined(CONFIG_IOSCHED_DEADLINE)
-        strcpy(chosen_elevator, "deadline");
-#elif defined(CONFIG_IOSCHED_CFQ)
-        strcpy(chosen_elevator, "cfq");
-#elif defined(CONFIG_IOSCHED_NOOP)
-        strcpy(chosen_elevator, "noop");
-#else
-#error "You must build at least 1 IO scheduler into the kernel"
-#endif
+        if (!chosen_elevator[0])
+                strcpy(chosen_elevator, CONFIG_DEFAULT_IOSCHED);
+
+        /*
+         * If the given scheduler is not available, fall back to no-op.
+         */
+        if (!(e = elevator_find(chosen_elevator)))
+                strcpy(chosen_elevator, "noop");
+        elevator_put(e);
 }
 
 static int __init elevator_setup(char *str)
@@ -186,6 +174,11 @@ int elevator_init(request_queue_t *q, char *name)
         struct elevator_queue *eq;
         int ret = 0;
 
+        INIT_LIST_HEAD(&q->queue_head);
+        q->last_merge = NULL;
+        q->end_sector = 0;
+        q->boundary_rq = NULL;
+
         elevator_setup_default();
 
         if (!name)
@@ -220,9 +213,52 @@ void elevator_exit(elevator_t *e)
         kfree(e);
 }
 
+/*
+ * Insert rq into dispatch queue of q.  Queue lock must be held on
+ * entry.  If sort != 0, rq is sort-inserted; otherwise, rq will be
+ * appended to the dispatch queue.  To be used by specific elevators.
+ */
+void elv_dispatch_sort(request_queue_t *q, struct request *rq)
+{
+        sector_t boundary;
+        struct list_head *entry;
+
+        if (q->last_merge == rq)
+                q->last_merge = NULL;
+
+        boundary = q->end_sector;
+
+        list_for_each_prev(entry, &q->queue_head) {
+                struct request *pos = list_entry_rq(entry);
+
+                if (pos->flags & (REQ_SOFTBARRIER|REQ_HARDBARRIER|REQ_STARTED))
+                        break;
+                if (rq->sector >= boundary) {
+                        if (pos->sector < boundary)
+                                continue;
+                } else {
+                        if (pos->sector >= boundary)
+                                break;
+                }
+                if (rq->sector >= pos->sector)
+                        break;
+        }
+
+        list_add(&rq->queuelist, entry);
+}
+
 int elv_merge(request_queue_t *q, struct request **req, struct bio *bio)
 {
         elevator_t *e = q->elevator;
+        int ret;
+
+        if (q->last_merge) {
+                ret = elv_try_merge(q->last_merge, bio);
+                if (ret != ELEVATOR_NO_MERGE) {
+                        *req = q->last_merge;
+                        return ret;
+                }
+        }
 
         if (e->ops->elevator_merge_fn)
                 return e->ops->elevator_merge_fn(q, req, bio);
@@ -236,6 +272,8 @@ void elv_merged_request(request_queue_t *q, struct request *rq)
 
         if (e->ops->elevator_merged_fn)
                 e->ops->elevator_merged_fn(q, rq);
+
+        q->last_merge = rq;
 }
 
 void elv_merge_requests(request_queue_t *q, struct request *rq,
@@ -243,20 +281,13 @@ void elv_merge_requests(request_queue_t *q, struct request *rq,
 {
         elevator_t *e = q->elevator;
 
-        if (q->last_merge == next)
-                q->last_merge = NULL;
-
         if (e->ops->elevator_merge_req_fn)
                 e->ops->elevator_merge_req_fn(q, rq, next);
+
+        q->last_merge = rq;
 }
 
-/*
- * For careful internal use by the block layer. Essentially the same as
- * a requeue in that it tells the io scheduler that this request is not
- * active in the driver or hardware anymore, but we don't want the request
- * added back to the scheduler. Function is not exported.
- */
-void elv_deactivate_request(request_queue_t *q, struct request *rq)
+void elv_requeue_request(request_queue_t *q, struct request *rq)
 {
         elevator_t *e = q->elevator;
 
@@ -264,19 +295,14 @@ void elv_deactivate_request(request_queue_t *q, struct request *rq)
          * it already went through dequeue, we need to decrement the
          * in_flight count again
          */
-        if (blk_account_rq(rq))
+        if (blk_account_rq(rq)) {
                 q->in_flight--;
+                if (blk_sorted_rq(rq) && e->ops->elevator_deactivate_req_fn)
+                        e->ops->elevator_deactivate_req_fn(q, rq);
+        }
 
         rq->flags &= ~REQ_STARTED;
 
-        if (e->ops->elevator_deactivate_req_fn)
-                e->ops->elevator_deactivate_req_fn(q, rq);
-}
-
-void elv_requeue_request(request_queue_t *q, struct request *rq)
-{
-        elv_deactivate_request(q, rq);
-
         /*
          * if this is the flush, requeue the original instead and drop the flush
          */
@@ -285,31 +311,27 @@ void elv_requeue_request(request_queue_t *q, struct request *rq)
                 rq = rq->end_io_data;
         }
 
-        /*
-         * the request is prepped and may have some resources allocated.
-         * allowing unprepped requests to pass this one may cause resource
-         * deadlock.  turn on softbarrier.
-         */
-        rq->flags |= REQ_SOFTBARRIER;
-
-        /*
-         * if iosched has an explicit requeue hook, then use that. otherwise
-         * just put the request at the front of the queue
-         */
-        if (q->elevator->ops->elevator_requeue_req_fn)
-                q->elevator->ops->elevator_requeue_req_fn(q, rq);
-        else
-                __elv_add_request(q, rq, ELEVATOR_INSERT_FRONT, 0);
+        __elv_add_request(q, rq, ELEVATOR_INSERT_FRONT, 0);
 }
 
 void __elv_add_request(request_queue_t *q, struct request *rq, int where,
                        int plug)
 {
-        /*
-         * barriers implicitly indicate back insertion
-         */
-        if (rq->flags & (REQ_SOFTBARRIER | REQ_HARDBARRIER) &&
-            where == ELEVATOR_INSERT_SORT)
+        if (rq->flags & (REQ_SOFTBARRIER | REQ_HARDBARRIER)) {
+                /*
+                 * barriers implicitly indicate back insertion
+                 */
+                if (where == ELEVATOR_INSERT_SORT)
+                        where = ELEVATOR_INSERT_BACK;
+
+                /*
+                 * this request is scheduling boundary, update end_sector
+                 */
+                if (blk_fs_request(rq)) {
+                        q->end_sector = rq_end_sector(rq);
+                        q->boundary_rq = rq;
+                }
+        } else if (!(rq->flags & REQ_ELVPRIV) && where == ELEVATOR_INSERT_SORT)
                 where = ELEVATOR_INSERT_BACK;
 
         if (plug)
@@ -317,23 +339,54 @@ void __elv_add_request(request_queue_t *q, struct request *rq, int where,
 
         rq->q = q;
 
-        if (!test_bit(QUEUE_FLAG_DRAIN, &q->queue_flags)) {
-                q->elevator->ops->elevator_add_req_fn(q, rq, where);
+        switch (where) {
+        case ELEVATOR_INSERT_FRONT:
+                rq->flags |= REQ_SOFTBARRIER;
 
-                if (blk_queue_plugged(q)) {
-                        int nrq = q->rq.count[READ] + q->rq.count[WRITE]
-                                  - q->in_flight;
+                list_add(&rq->queuelist, &q->queue_head);
+                break;
 
-                        if (nrq >= q->unplug_thresh)
-                                __generic_unplug_device(q);
-                }
-        } else
+        case ELEVATOR_INSERT_BACK:
+                rq->flags |= REQ_SOFTBARRIER;
+
+                while (q->elevator->ops->elevator_dispatch_fn(q, 1))
+                        ;
+                list_add_tail(&rq->queuelist, &q->queue_head);
                 /*
-                 * if drain is set, store the request "locally". when the drain
-                 * is finished, the requests will be handed ordered to the io
-                 * scheduler
+                 * We kick the queue here for the following reasons.
+                 * - The elevator might have returned NULL previously
+                 *   to delay requests and returned them now.  As the
+                 *   queue wasn't empty before this request, ll_rw_blk
+                 *   won't run the queue on return, resulting in hang.
+                 * - Usually, back inserted requests won't be merged
+                 *   with anything.  There's no point in delaying queue
+                 *   processing.
                  */
-                list_add_tail(&rq->queuelist, &q->drain_list);
+                blk_remove_plug(q);
+                q->request_fn(q);
+                break;
+
+        case ELEVATOR_INSERT_SORT:
+                BUG_ON(!blk_fs_request(rq));
+                rq->flags |= REQ_SORTED;
+                q->elevator->ops->elevator_add_req_fn(q, rq);
+                if (q->last_merge == NULL && rq_mergeable(rq))
+                        q->last_merge = rq;
+                break;
+
+        default:
+                printk(KERN_ERR "%s: bad insertion point %d\n",
+                       __FUNCTION__, where);
+                BUG();
+        }
+
+        if (blk_queue_plugged(q)) {
+                int nrq = q->rq.count[READ] + q->rq.count[WRITE]
+                        - q->in_flight;
+
+                if (nrq >= q->unplug_thresh)
+                        __generic_unplug_device(q);
+        }
 }
 
 void elv_add_request(request_queue_t *q, struct request *rq, int where,
@@ -348,13 +401,19 @@ void elv_add_request(request_queue_t *q, struct request *rq, int where,
 
 static inline struct request *__elv_next_request(request_queue_t *q)
 {
-        struct request *rq = q->elevator->ops->elevator_next_req_fn(q);
+        struct request *rq;
+
+        if (unlikely(list_empty(&q->queue_head) &&
+                     !q->elevator->ops->elevator_dispatch_fn(q, 0)))
+                return NULL;
+
+        rq = list_entry_rq(q->queue_head.next);
 
         /*
          * if this is a barrier write and the device has to issue a
          * flush sequence to support it, check how far we are
          */
-        if (rq && blk_fs_request(rq) && blk_barrier_rq(rq)) {
+        if (blk_fs_request(rq) && blk_barrier_rq(rq)) {
                 BUG_ON(q->ordered == QUEUE_ORDERED_NONE);
 
                 if (q->ordered == QUEUE_ORDERED_FLUSH &&
@@ -371,15 +430,30 @@ struct request *elv_next_request(request_queue_t *q)
         int ret;
 
         while ((rq = __elv_next_request(q)) != NULL) {
-                /*
-                 * just mark as started even if we don't start it, a request
-                 * that has been delayed should not be passed by new incoming
-                 * requests
-                 */
-                rq->flags |= REQ_STARTED;
+                if (!(rq->flags & REQ_STARTED)) {
+                        elevator_t *e = q->elevator;
+
+                        /*
+                         * This is the first time the device driver
+                         * sees this request (possibly after
+                         * requeueing).  Notify IO scheduler.
+                         */
+                        if (blk_sorted_rq(rq) &&
+                            e->ops->elevator_activate_req_fn)
+                                e->ops->elevator_activate_req_fn(q, rq);
+
+                        /*
+                         * just mark as started even if we don't start
+                         * it, a request that has been delayed should
+                         * not be passed by new incoming requests
+                         */
+                        rq->flags |= REQ_STARTED;
+                }
 
-                if (rq == q->last_merge)
-                        q->last_merge = NULL;
+                if (!q->boundary_rq || q->boundary_rq == rq) {
+                        q->end_sector = rq_end_sector(rq);
+                        q->boundary_rq = NULL;
+                }
 
                 if ((rq->flags & REQ_DONTPREP) || !q->prep_rq_fn)
                         break;
@@ -391,9 +465,9 @@ struct request *elv_next_request(request_queue_t *q)
                         /*
                          * the request may have been (partially) prepped.
                          * we need to keep this request in the front to
-                         * avoid resource deadlock.  turn on softbarrier.
+                         * avoid resource deadlock.  REQ_STARTED will
+                         * prevent other fs requests from passing this one.
                          */
-                        rq->flags |= REQ_SOFTBARRIER;
                         rq = NULL;
                         break;
                 } else if (ret == BLKPREP_KILL) {
@@ -416,42 +490,32 @@ struct request *elv_next_request(request_queue_t *q)
         return rq;
 }
 
-void elv_remove_request(request_queue_t *q, struct request *rq)
+void elv_dequeue_request(request_queue_t *q, struct request *rq)
 {
-        elevator_t *e = q->elevator;
+        BUG_ON(list_empty(&rq->queuelist));
+
+        list_del_init(&rq->queuelist);
 
         /*
          * the time frame between a request being removed from the lists
          * and to it is freed is accounted as io that is in progress at
-         * the driver side. note that we only account requests that the
-         * driver has seen (REQ_STARTED set), to avoid false accounting
-         * for request-request merges
+         * the driver side.
          */
         if (blk_account_rq(rq))
                 q->in_flight++;
-
-        /*
-         * the main clearing point for q->last_merge is on retrieval of
-         * request by driver (it calls elv_next_request()), but it _can_
-         * also happen here if a request is added to the queue but later
-         * deleted without ever being given to driver (merged with another
-         * request).
-         */
-        if (rq == q->last_merge)
-                q->last_merge = NULL;
-
-        if (e->ops->elevator_remove_req_fn)
-                e->ops->elevator_remove_req_fn(q, rq);
 }
 
 int elv_queue_empty(request_queue_t *q)
 {
         elevator_t *e = q->elevator;
 
+        if (!list_empty(&q->queue_head))
+                return 0;
+
         if (e->ops->elevator_queue_empty_fn)
                 return e->ops->elevator_queue_empty_fn(q);
 
-        return list_empty(&q->queue_head);
+        return 1;
 }
 
 struct request *elv_latter_request(request_queue_t *q, struct request *rq)
@@ -487,7 +551,7 @@ struct request *elv_former_request(request_queue_t *q, struct request *rq)
 }
 
 int elv_set_request(request_queue_t *q, struct request *rq, struct bio *bio,
-                    int gfp_mask)
+                    gfp_t gfp_mask)
 {
         elevator_t *e = q->elevator;
 
@@ -523,11 +587,11 @@ void elv_completed_request(request_queue_t *q, struct request *rq)
         /*
          * request is released from the driver, io must be done
          */
-        if (blk_account_rq(rq))
+        if (blk_account_rq(rq)) {
                 q->in_flight--;
-
-        if (e->ops->elevator_completed_req_fn)
-                e->ops->elevator_completed_req_fn(q, rq);
+                if (blk_sorted_rq(rq) && e->ops->elevator_completed_req_fn)
+                        e->ops->elevator_completed_req_fn(q, rq);
+        }
 }
 
 int elv_register_queue(struct request_queue *q)
@@ -555,10 +619,9 @@ void elv_unregister_queue(struct request_queue *q)
 
 int elv_register(struct elevator_type *e)
 {
+        spin_lock_irq(&elv_list_lock);
         if (elevator_find(e->elevator_name))
                 BUG();
-
-        spin_lock_irq(&elv_list_lock);
         list_add_tail(&e->list, &elv_list);
         spin_unlock_irq(&elv_list_lock);
 
@@ -572,6 +635,27 @@ EXPORT_SYMBOL_GPL(elv_register);
 
 void elv_unregister(struct elevator_type *e)
 {
+        struct task_struct *g, *p;
+
+        /*
+         * Iterate every thread in the process to remove the io contexts.
+         */
+        read_lock(&tasklist_lock);
+        do_each_thread(g, p) {
+                struct io_context *ioc = p->io_context;
+                if (ioc && ioc->cic) {
+                        ioc->cic->exit(ioc->cic);
+                        ioc->cic->dtor(ioc->cic);
+                        ioc->cic = NULL;
+                }
+                if (ioc && ioc->aic) {
+                        ioc->aic->exit(ioc->aic);
+                        ioc->aic->dtor(ioc->aic);
+                        ioc->aic = NULL;
+                }
+        } while_each_thread(g, p);
+        read_unlock(&tasklist_lock);
+
         spin_lock_irq(&elv_list_lock);
         list_del_init(&e->list);
         spin_unlock_irq(&elv_list_lock);
@@ -582,25 +666,36 @@ EXPORT_SYMBOL_GPL(elv_unregister);
  * switch to new_e io scheduler. be careful not to introduce deadlocks -
  * we don't free the old io scheduler, before we have allocated what we
  * need for the new one. this way we have a chance of going back to the old
- * one, if the new one fails init for some reason. we also do an intermediate
- * switch to noop to ensure safety with stack-allocated requests, since they
- * don't originate from the block layer allocator. noop is safe here, because
- * it never needs to touch the elevator itself for completion events. DRAIN
- * flags will make sure we don't touch it for additions either.
+ * one, if the new one fails init for some reason.
  */
 static void elevator_switch(request_queue_t *q, struct elevator_type *new_e)
 {
-        elevator_t *e = kmalloc(sizeof(elevator_t), GFP_KERNEL);
-        struct elevator_type *noop_elevator = NULL;
-        elevator_t *old_elevator;
+        elevator_t *old_elevator, *e;
 
+        /*
+         * Allocate new elevator
+         */
+        e = kmalloc(sizeof(elevator_t), GFP_KERNEL);
         if (!e)
                 goto error;
 
         /*
-         * first step, drain requests from the block freelist
+         * Turn on BYPASS and drain all requests w/ elevator private data
          */
-        blk_wait_queue_drained(q, 0);
+        spin_lock_irq(q->queue_lock);
+
+        set_bit(QUEUE_FLAG_ELVSWITCH, &q->queue_flags);
+
+        while (q->elevator->ops->elevator_dispatch_fn(q, 1))
+                ;
+
+        while (q->rq.elvpriv) {
+                spin_unlock_irq(q->queue_lock);
+                msleep(10);
+                spin_lock_irq(q->queue_lock);
+        }
+
+        spin_unlock_irq(q->queue_lock);
 
         /*
          * unregister old elevator data
@@ -609,18 +704,6 @@ static void elevator_switch(request_queue_t *q, struct elevator_type *new_e)
         old_elevator = q->elevator;
 
         /*
-         * next step, switch to noop since it uses no private rq structures
-         * and doesn't allocate any memory for anything. then wait for any
-         * non-fs requests in-flight
-         */
-        noop_elevator = elevator_get("noop");
-        spin_lock_irq(q->queue_lock);
-        elevator_attach(q, noop_elevator, e);
-        spin_unlock_irq(q->queue_lock);
-
-        blk_wait_queue_drained(q, 1);
-
-        /*
          * attach and start new elevator
          */
         if (elevator_attach(q, new_e, e))
@@ -630,11 +713,10 @@ static void elevator_switch(request_queue_t *q, struct elevator_type *new_e)
                 goto fail_register;
 
         /*
-         * finally exit old elevator and start queue again
+         * finally exit old elevator and turn off BYPASS.
          */
         elevator_exit(old_elevator);
-        blk_finish_queue_drain(q);
-        elevator_put(noop_elevator);
+        clear_bit(QUEUE_FLAG_ELVSWITCH, &q->queue_flags);
         return;
 
 fail_register:
@@ -643,13 +725,13 @@ fail_register:
          * one again (along with re-adding the sysfs dir)
          */
         elevator_exit(e);
+        e = NULL;
 fail:
         q->elevator = old_elevator;
         elv_register_queue(q);
-        blk_finish_queue_drain(q);
+        clear_bit(QUEUE_FLAG_ELVSWITCH, &q->queue_flags);
+        kfree(e);
 error:
-        if (noop_elevator)
-                elevator_put(noop_elevator);
         elevator_put(new_e);
         printk(KERN_ERR "elevator: switch to %s failed\n",new_e->elevator_name);
 }
@@ -671,8 +753,10 @@ ssize_t elv_iosched_store(request_queue_t *q, const char *name, size_t count)
                 return -EINVAL;
         }
 
-        if (!strcmp(elevator_name, q->elevator->elevator_type->elevator_name))
+        if (!strcmp(elevator_name, q->elevator->elevator_type->elevator_name)) {
+                elevator_put(e);
                 return count;
+        }
 
         elevator_switch(q, e);
         return count;
@@ -701,11 +785,12 @@ ssize_t elv_iosched_show(request_queue_t *q, char *name)
         return len;
 }
 
+EXPORT_SYMBOL(elv_dispatch_sort);
 EXPORT_SYMBOL(elv_add_request);
 EXPORT_SYMBOL(__elv_add_request);
 EXPORT_SYMBOL(elv_requeue_request);
 EXPORT_SYMBOL(elv_next_request);
-EXPORT_SYMBOL(elv_remove_request);
+EXPORT_SYMBOL(elv_dequeue_request);
 EXPORT_SYMBOL(elv_queue_empty);
 EXPORT_SYMBOL(elv_completed_request);
 EXPORT_SYMBOL(elevator_exit);
diff --git a/drivers/block/genhd.c b/drivers/block/genhd.c
index d42840cc0d1d..486ce1fdeb8c 100644
--- a/drivers/block/genhd.c
+++ b/drivers/block/genhd.c
@@ -337,10 +337,30 @@ static ssize_t disk_attr_show(struct kobject *kobj, struct attribute *attr,
         return ret;
 }
 
+static ssize_t disk_attr_store(struct kobject * kobj, struct attribute * attr,
+                               const char *page, size_t count)
+{
+        struct gendisk *disk = to_disk(kobj);
+        struct disk_attribute *disk_attr =
+                container_of(attr,struct disk_attribute,attr);
+        ssize_t ret = 0;
+
+        if (disk_attr->store)
+                ret = disk_attr->store(disk, page, count);
+        return ret;
+}
+
 static struct sysfs_ops disk_sysfs_ops = {
         .show   = &disk_attr_show,
+        .store  = &disk_attr_store,
 };
 
+static ssize_t disk_uevent_store(struct gendisk * disk,
+                                 const char *buf, size_t count)
+{
+        kobject_hotplug(&disk->kobj, KOBJ_ADD);
+        return count;
+}
 static ssize_t disk_dev_read(struct gendisk * disk, char *page)
 {
         dev_t base = MKDEV(disk->major, disk->first_minor); 
@@ -382,6 +402,10 @@ static ssize_t disk_stats_read(struct gendisk * disk, char *page)
                 jiffies_to_msecs(disk_stat_read(disk, io_ticks)),
                 jiffies_to_msecs(disk_stat_read(disk, time_in_queue)));
 }
+static struct disk_attribute disk_attr_uevent = {
+        .attr = {.name = "uevent", .mode = S_IWUSR },
+        .store  = disk_uevent_store
+};
 static struct disk_attribute disk_attr_dev = {
         .attr = {.name = "dev", .mode = S_IRUGO },
         .show   = disk_dev_read
@@ -404,6 +428,7 @@ static struct disk_attribute disk_attr_stat = {
 };
 
 static struct attribute * default_attrs[] = {
+        &disk_attr_uevent.attr,
         &disk_attr_dev.attr,
         &disk_attr_range.attr,
         &disk_attr_removable.attr,
diff --git a/drivers/block/ll_rw_blk.c b/drivers/block/ll_rw_blk.c
index baedac522945..0af73512b9a8 100644
--- a/drivers/block/ll_rw_blk.c
+++ b/drivers/block/ll_rw_blk.c
@@ -263,8 +263,6 @@ void blk_queue_make_request(request_queue_t * q, make_request_fn * mfn)
         blk_queue_bounce_limit(q, BLK_BOUNCE_HIGH);
 
         blk_queue_activity_fn(q, NULL, NULL);
-
-        INIT_LIST_HEAD(&q->drain_list);
 }
 
 EXPORT_SYMBOL(blk_queue_make_request);
@@ -353,6 +351,8 @@ static void blk_pre_flush_end_io(struct request *flush_rq)
         struct request *rq = flush_rq->end_io_data;
         request_queue_t *q = rq->q;
 
+        elv_completed_request(q, flush_rq);
+
         rq->flags |= REQ_BAR_PREFLUSH;
 
         if (!flush_rq->errors)
@@ -369,6 +369,8 @@ static void blk_post_flush_end_io(struct request *flush_rq)
         struct request *rq = flush_rq->end_io_data;
         request_queue_t *q = rq->q;
 
+        elv_completed_request(q, flush_rq);
+
         rq->flags |= REQ_BAR_POSTFLUSH;
 
         q->end_flush_fn(q, flush_rq);
@@ -408,8 +410,6 @@ struct request *blk_start_pre_flush(request_queue_t *q, struct request *rq)
         if (!list_empty(&rq->queuelist))
                 blkdev_dequeue_request(rq);
 
-        elv_deactivate_request(q, rq);
-
         flush_rq->end_io_data = rq;
         flush_rq->end_io = blk_pre_flush_end_io;
 
@@ -1040,6 +1040,7 @@ EXPORT_SYMBOL(blk_queue_invalidate_tags);
 static char *rq_flags[] = {
         "REQ_RW",
         "REQ_FAILFAST",
+        "REQ_SORTED",
         "REQ_SOFTBARRIER",
         "REQ_HARDBARRIER",
         "REQ_CMD",
@@ -1047,6 +1048,7 @@ static char *rq_flags[] = {
         "REQ_STARTED",
         "REQ_DONTPREP",
         "REQ_QUEUED",
+        "REQ_ELVPRIV",
         "REQ_PC",
         "REQ_BLOCK_PC",
         "REQ_SENSE",
@@ -1637,9 +1639,9 @@ static int blk_init_free_list(request_queue_t *q)
 
         rl->count[READ] = rl->count[WRITE] = 0;
         rl->starved[READ] = rl->starved[WRITE] = 0;
+        rl->elvpriv = 0;
         init_waitqueue_head(&rl->wait[READ]);
         init_waitqueue_head(&rl->wait[WRITE]);
-        init_waitqueue_head(&rl->drain);
 
         rl->rq_pool = mempool_create_node(BLKDEV_MIN_RQ, mempool_alloc_slab,
                                 mempool_free_slab, request_cachep, q->node);
@@ -1652,13 +1654,13 @@ static int blk_init_free_list(request_queue_t *q)
 
 static int __make_request(request_queue_t *, struct bio *);
 
-request_queue_t *blk_alloc_queue(int gfp_mask)
+request_queue_t *blk_alloc_queue(gfp_t gfp_mask)
 {
         return blk_alloc_queue_node(gfp_mask, -1);
 }
 EXPORT_SYMBOL(blk_alloc_queue);
 
-request_queue_t *blk_alloc_queue_node(int gfp_mask, int node_id)
+request_queue_t *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
 {
         request_queue_t *q;
 
@@ -1782,12 +1784,14 @@ EXPORT_SYMBOL(blk_get_queue);
 
 static inline void blk_free_request(request_queue_t *q, struct request *rq)
 {
-        elv_put_request(q, rq);
+        if (rq->flags & REQ_ELVPRIV)
+                elv_put_request(q, rq);
         mempool_free(rq, q->rq.rq_pool);
 }
 
 static inline struct request *
-blk_alloc_request(request_queue_t *q, int rw, struct bio *bio, int gfp_mask)
+blk_alloc_request(request_queue_t *q, int rw, struct bio *bio,
+                  int priv, gfp_t gfp_mask)
 {
         struct request *rq = mempool_alloc(q->rq.rq_pool, gfp_mask);
 
@@ -1800,11 +1804,15 @@ blk_alloc_request(request_queue_t *q, int rw, struct bio *bio, int gfp_mask)
          */
         rq->flags = rw;
 
-        if (!elv_set_request(q, rq, bio, gfp_mask))
-                return rq;
+        if (priv) {
+                if (unlikely(elv_set_request(q, rq, bio, gfp_mask))) {
+                        mempool_free(rq, q->rq.rq_pool);
+                        return NULL;
+                }
+                rq->flags |= REQ_ELVPRIV;
+        }
 
-        mempool_free(rq, q->rq.rq_pool);
-        return NULL;
+        return rq;
 }
 
 /*
@@ -1860,22 +1868,18 @@ static void __freed_request(request_queue_t *q, int rw)
  * 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(request_queue_t *q, int rw)
+static void freed_request(request_queue_t *q, int rw, int priv)
 {
         struct request_list *rl = &q->rq;
 
         rl->count[rw]--;
+        if (priv)
+                rl->elvpriv--;
 
         __freed_request(q, rw);
 
         if (unlikely(rl->starved[rw ^ 1]))
                 __freed_request(q, rw ^ 1);
-
-        if (!rl->count[READ] && !rl->count[WRITE]) {
-                smp_mb();
-                if (unlikely(waitqueue_active(&rl->drain)))
-                        wake_up(&rl->drain);
-        }
 }
 
 #define blkdev_free_rq(list) list_entry((list)->next, struct request, queuelist)
@@ -1885,14 +1889,12 @@ static void freed_request(request_queue_t *q, int rw)
  * Returns !NULL on success, with queue_lock *not held*.
  */
 static struct request *get_request(request_queue_t *q, int rw, struct bio *bio,
-                                   int gfp_mask)
+                                   gfp_t gfp_mask)
 {
         struct request *rq = NULL;
         struct request_list *rl = &q->rq;
         struct io_context *ioc = current_io_context(GFP_ATOMIC);
-
-        if (unlikely(test_bit(QUEUE_FLAG_DRAIN, &q->queue_flags)))
-                goto out;
+        int priv;
 
         if (rl->count[rw]+1 >= q->nr_requests) {
                 /*
@@ -1937,9 +1939,14 @@ get_rq:
         rl->starved[rw] = 0;
         if (rl->count[rw] >= queue_congestion_on_threshold(q))
                 set_queue_congested(q, rw);
+
+        priv = !test_bit(QUEUE_FLAG_ELVSWITCH, &q->queue_flags);
+        if (priv)
+                rl->elvpriv++;
+
         spin_unlock_irq(q->queue_lock);
 
-        rq = blk_alloc_request(q, rw, bio, gfp_mask);
+        rq = blk_alloc_request(q, rw, bio, priv, gfp_mask);
         if (!rq) {
                 /*
                  * Allocation failed presumably due to memory. Undo anything
@@ -1949,7 +1956,7 @@ get_rq:
                  * wait queue, but this is pretty rare.
                  */
                 spin_lock_irq(q->queue_lock);
-                freed_request(q, rw);
+                freed_request(q, rw, priv);
 
                 /*
                  * in the very unlikely event that allocation failed and no
@@ -2019,7 +2026,7 @@ static struct request *get_request_wait(request_queue_t *q, int rw,
         return rq;
 }
 
-struct request *blk_get_request(request_queue_t *q, int rw, int gfp_mask)
+struct request *blk_get_request(request_queue_t *q, int rw, gfp_t gfp_mask)
 {
         struct request *rq;
 
@@ -2251,7 +2258,7 @@ EXPORT_SYMBOL(blk_rq_unmap_user);
  * @gfp_mask:   memory allocation flags
  */
 int blk_rq_map_kern(request_queue_t *q, struct request *rq, void *kbuf,
-                    unsigned int len, unsigned int gfp_mask)
+                    unsigned int len, gfp_t gfp_mask)
 {
         struct bio *bio;
 
@@ -2433,13 +2440,15 @@ void disk_round_stats(struct gendisk *disk)
 {
         unsigned long now = jiffies;
 
-        __disk_stat_add(disk, time_in_queue,
-                        disk->in_flight * (now - disk->stamp));
-        disk->stamp = now;
+        if (now == disk->stamp)
+                return;
 
-        if (disk->in_flight)
-                __disk_stat_add(disk, io_ticks, (now - disk->stamp_idle));
-        disk->stamp_idle = now;
+        if (disk->in_flight) {
+                __disk_stat_add(disk, time_in_queue,
+                                disk->in_flight * (now - disk->stamp));
+                __disk_stat_add(disk, io_ticks, (now - disk->stamp));
+        }
+        disk->stamp = now;
 }
 
 /*
@@ -2454,6 +2463,8 @@ static void __blk_put_request(request_queue_t *q, struct request *req)
         if (unlikely(--req->ref_count))
                 return;
 
+        elv_completed_request(q, req);
+
         req->rq_status = RQ_INACTIVE;
         req->rl = NULL;
 
@@ -2463,26 +2474,25 @@ static void __blk_put_request(request_queue_t *q, struct request *req)
          */
         if (rl) {
                 int rw = rq_data_dir(req);
-
-                elv_completed_request(q, req);
+                int priv = req->flags & REQ_ELVPRIV;
 
                 BUG_ON(!list_empty(&req->queuelist));
 
                 blk_free_request(q, req);
-                freed_request(q, rw);
+                freed_request(q, rw, priv);
         }
 }
 
 void blk_put_request(struct request *req)
 {
+        unsigned long flags;
+        request_queue_t *q = req->q;
+
         /*
-         * if req->rl isn't set, this request didnt originate from the
-         * block layer, so it's safe to just disregard it
+         * Gee, IDE calls in w/ NULL q.  Fix IDE and remove the
+         * following if (q) test.
          */
-        if (req->rl) {
-                unsigned long flags;
-                request_queue_t *q = req->q;
-
+        if (q) {
                 spin_lock_irqsave(q->queue_lock, flags);
                 __blk_put_request(q, req);
                 spin_unlock_irqrestore(q->queue_lock, flags);
@@ -2797,97 +2807,6 @@ static inline void blk_partition_remap(struct bio *bio)
         }
 }
 
-void blk_finish_queue_drain(request_queue_t *q)
-{
-        struct request_list *rl = &q->rq;
-        struct request *rq;
-        int requeued = 0;
-
-        spin_lock_irq(q->queue_lock);
-        clear_bit(QUEUE_FLAG_DRAIN, &q->queue_flags);
-
-        while (!list_empty(&q->drain_list)) {
-                rq = list_entry_rq(q->drain_list.next);
-
-                list_del_init(&rq->queuelist);
-                elv_requeue_request(q, rq);
-                requeued++;
-        }
-
-        if (requeued)
-                q->request_fn(q);
-
-        spin_unlock_irq(q->queue_lock);
-
-        wake_up(&rl->wait[0]);
-        wake_up(&rl->wait[1]);
-        wake_up(&rl->drain);
-}
-
-static int wait_drain(request_queue_t *q, struct request_list *rl, int dispatch)
-{
-        int wait = rl->count[READ] + rl->count[WRITE];
-
-        if (dispatch)
-                wait += !list_empty(&q->queue_head);
-
-        return wait;
-}
-
-/*
- * We rely on the fact that only requests allocated through blk_alloc_request()
- * have io scheduler private data structures associated with them. Any other
- * type of request (allocated on stack or through kmalloc()) should not go
- * to the io scheduler core, but be attached to the queue head instead.
- */
-void blk_wait_queue_drained(request_queue_t *q, int wait_dispatch)
-{
-        struct request_list *rl = &q->rq;
-        DEFINE_WAIT(wait);
-
-        spin_lock_irq(q->queue_lock);
-        set_bit(QUEUE_FLAG_DRAIN, &q->queue_flags);
-
-        while (wait_drain(q, rl, wait_dispatch)) {
-                prepare_to_wait(&rl->drain, &wait, TASK_UNINTERRUPTIBLE);
-
-                if (wait_drain(q, rl, wait_dispatch)) {
-                        __generic_unplug_device(q);
-                        spin_unlock_irq(q->queue_lock);
-                        io_schedule();
-                        spin_lock_irq(q->queue_lock);
-                }
-
-                finish_wait(&rl->drain, &wait);
-        }
-
-        spin_unlock_irq(q->queue_lock);
-}
-
-/*
- * block waiting for the io scheduler being started again.
- */
-static inline void block_wait_queue_running(request_queue_t *q)
-{
-        DEFINE_WAIT(wait);
-
-        while (unlikely(test_bit(QUEUE_FLAG_DRAIN, &q->queue_flags))) {
-                struct request_list *rl = &q->rq;
-
-                prepare_to_wait_exclusive(&rl->drain, &wait,
-                                TASK_UNINTERRUPTIBLE);
-
-                /*
-                 * re-check the condition. avoids using prepare_to_wait()
-                 * in the fast path (queue is running)
-                 */
-                if (test_bit(QUEUE_FLAG_DRAIN, &q->queue_flags))
-                        io_schedule();
-
-                finish_wait(&rl->drain, &wait);
-        }
-}
-
 static void handle_bad_sector(struct bio *bio)
 {
         char b[BDEVNAME_SIZE];
@@ -2983,8 +2902,6 @@ end_io:
                 if (unlikely(test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)))
                         goto end_io;
 
-                block_wait_queue_running(q);
-
                 /*
                  * If this device has partitions, remap block n
                  * of partition p to block n+start(p) of the disk.
@@ -3393,7 +3310,7 @@ void exit_io_context(void)
  * but since the current task itself holds a reference, the context can be
  * used in general code, so long as it stays within `current` context.
  */
-struct io_context *current_io_context(int gfp_flags)
+struct io_context *current_io_context(gfp_t gfp_flags)
 {
         struct task_struct *tsk = current;
         struct io_context *ret;
@@ -3424,7 +3341,7 @@ EXPORT_SYMBOL(current_io_context);
  *
  * This is always called in the context of the task which submitted the I/O.
  */
-struct io_context *get_io_context(int gfp_flags)
+struct io_context *get_io_context(gfp_t gfp_flags)
 {
         struct io_context *ret;
         ret = current_io_context(gfp_flags);
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index b35e08876dd4..96c664af8d06 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -881,7 +881,7 @@ loop_init_xfer(struct loop_device *lo, struct loop_func_table *xfer,
 static int loop_clr_fd(struct loop_device *lo, struct block_device *bdev)
 {
         struct file *filp = lo->lo_backing_file;
-        int gfp = lo->old_gfp_mask;
+        gfp_t gfp = lo->old_gfp_mask;
 
         if (lo->lo_state != Lo_bound)
                 return -ENXIO;
diff --git a/drivers/block/noop-iosched.c b/drivers/block/noop-iosched.c
index b1730b62c37e..f56b8edb06e4 100644
--- a/drivers/block/noop-iosched.c
+++ b/drivers/block/noop-iosched.c
@@ -7,57 +7,19 @@
 #include <linux/module.h>
 #include <linux/init.h>
 
-/*
- * See if we can find a request that this buffer can be coalesced with.
- */
-static int elevator_noop_merge(request_queue_t *q, struct request **req,
-                               struct bio *bio)
-{
-        int ret;
-
-        ret = elv_try_last_merge(q, bio);
-        if (ret != ELEVATOR_NO_MERGE)
-                *req = q->last_merge;
-
-        return ret;
-}
-
-static void elevator_noop_merge_requests(request_queue_t *q, struct request *req,
-                                         struct request *next)
-{
-        list_del_init(&next->queuelist);
-}
-
-static void elevator_noop_add_request(request_queue_t *q, struct request *rq,
-                                      int where)
+static void elevator_noop_add_request(request_queue_t *q, struct request *rq)
 {
-        if (where == ELEVATOR_INSERT_FRONT)
-                list_add(&rq->queuelist, &q->queue_head);
-        else
-                list_add_tail(&rq->queuelist, &q->queue_head);
-
-        /*
-         * new merges must not precede this barrier
-         */
-        if (rq->flags & REQ_HARDBARRIER)
-                q->last_merge = NULL;
-        else if (!q->last_merge)
-                q->last_merge = rq;
+        elv_dispatch_add_tail(q, rq);
 }
 
-static struct request *elevator_noop_next_request(request_queue_t *q)
+static int elevator_noop_dispatch(request_queue_t *q, int force)
 {
-        if (!list_empty(&q->queue_head))
-                return list_entry_rq(q->queue_head.next);
-
-        return NULL;
+        return 0;
 }
 
 static struct elevator_type elevator_noop = {
         .ops = {
-                .elevator_merge_fn              = elevator_noop_merge,
-                .elevator_merge_req_fn          = elevator_noop_merge_requests,
-                .elevator_next_req_fn           = elevator_noop_next_request,
+                .elevator_dispatch_fn           = elevator_noop_dispatch,
                 .elevator_add_req_fn            = elevator_noop_add_request,
         },
         .elevator_name = "noop",
diff --git a/drivers/block/paride/paride.c b/drivers/block/paride/paride.c
index 1fef136c0e41..ce94aa11f6a7 100644
--- a/drivers/block/paride/paride.c
+++ b/drivers/block/paride/paride.c
@@ -29,6 +29,7 @@
 #include <linux/string.h>
 #include <linux/spinlock.h>
 #include <linux/wait.h>
+#include <linux/sched.h>        /* TASK_* */
 
 #ifdef CONFIG_PARPORT_MODULE
 #define CONFIG_PARPORT
diff --git a/drivers/block/paride/pf.c b/drivers/block/paride/pf.c
index 94af920465b5..e9746af29b9f 100644
--- a/drivers/block/paride/pf.c
+++ b/drivers/block/paride/pf.c
@@ -807,10 +807,6 @@ static int pf_next_buf(void)
                 return 1;
         spin_lock_irqsave(&pf_spin_lock, saved_flags);
         pf_end_request(1);
-        if (pf_req) {
-                pf_count = pf_req->current_nr_sectors;
-                pf_buf = pf_req->buffer;
-        }
         spin_unlock_irqrestore(&pf_spin_lock, saved_flags);
         return 1;
 }
diff --git a/drivers/block/paride/pg.c b/drivers/block/paride/pg.c
index b3982395f22b..6f5df0fad703 100644
--- a/drivers/block/paride/pg.c
+++ b/drivers/block/paride/pg.c
@@ -162,6 +162,8 @@ enum {D_PRT, D_PRO, D_UNI, D_MOD, D_SLV, D_DLY};
 #include <linux/mtio.h>
 #include <linux/pg.h>
 #include <linux/device.h>
+#include <linux/sched.h>        /* current, TASK_* */
+#include <linux/jiffies.h>
 
 #include <asm/uaccess.h>
 
@@ -674,7 +676,7 @@ static int __init pg_init(void)
         for (unit = 0; unit < PG_UNITS; unit++) {
                 struct pg *dev = &devices[unit];
                 if (dev->present) {
-                        class_device_create(pg_class, MKDEV(major, unit),
+                        class_device_create(pg_class, NULL, MKDEV(major, unit),
                                         NULL, "pg%u", unit);
                         err = devfs_mk_cdev(MKDEV(major, unit),
                                       S_IFCHR | S_IRUSR | S_IWUSR, "pg/%u",
diff --git a/drivers/block/paride/pt.c b/drivers/block/paride/pt.c
index d8d35233cf49..715ae5dc88fb 100644
--- a/drivers/block/paride/pt.c
+++ b/drivers/block/paride/pt.c
@@ -146,6 +146,7 @@ static int (*drives[4])[6] = {&drive0, &drive1, &drive2, &drive3};
 #include <linux/slab.h>
 #include <linux/mtio.h>
 #include <linux/device.h>
+#include <linux/sched.h>        /* current, TASK_*, schedule_timeout() */
 
 #include <asm/uaccess.h>
 
@@ -971,7 +972,7 @@ static int __init pt_init(void)
         devfs_mk_dir("pt");
         for (unit = 0; unit < PT_UNITS; unit++)
                 if (pt[unit].present) {
-                        class_device_create(pt_class, MKDEV(major, unit),
+                        class_device_create(pt_class, NULL, MKDEV(major, unit),
                                         NULL, "pt%d", unit);
                         err = devfs_mk_cdev(MKDEV(major, unit),
                                       S_IFCHR | S_IRUSR | S_IWUSR,
@@ -980,7 +981,7 @@ static int __init pt_init(void)
                                 class_device_destroy(pt_class, MKDEV(major, unit));
                                 goto out_class;
                         }
-                        class_device_create(pt_class, MKDEV(major, unit + 128),
+                        class_device_create(pt_class, NULL, MKDEV(major, unit + 128),
                                         NULL, "pt%dn", unit);
                         err = devfs_mk_cdev(MKDEV(major, unit + 128),
                                       S_IFCHR | S_IRUSR | S_IWUSR,
diff --git a/drivers/block/rd.c b/drivers/block/rd.c
index 145c1fbffe01..68c60a5bcdab 100644
--- a/drivers/block/rd.c
+++ b/drivers/block/rd.c
@@ -348,7 +348,7 @@ static int rd_open(struct inode *inode, struct file *filp)
                 struct block_device *bdev = inode->i_bdev;
                 struct address_space *mapping;
                 unsigned bsize;
-                int gfp_mask;
+                gfp_t gfp_mask;
 
                 inode = igrab(bdev->bd_inode);
                 rd_bdev[unit] = bdev;
diff --git a/drivers/block/sx8.c b/drivers/block/sx8.c
index d57007b92f77..1ded3b433459 100644
--- a/drivers/block/sx8.c
+++ b/drivers/block/sx8.c
@@ -1,7 +1,7 @@
 /*
  *  sx8.c: Driver for Promise SATA SX8 looks-like-I2O hardware
  *
- *  Copyright 2004 Red Hat, Inc.
+ *  Copyright 2004-2005 Red Hat, Inc.
  *
  *  Author/maintainer:  Jeff Garzik <jgarzik@pobox.com>
  *
@@ -31,10 +31,6 @@
 #include <asm/semaphore.h>
 #include <asm/uaccess.h>
 
-MODULE_AUTHOR("Jeff Garzik");
-MODULE_LICENSE("GPL");
-MODULE_DESCRIPTION("Promise SATA SX8 block driver");
-
 #if 0
 #define CARM_DEBUG
 #define CARM_VERBOSE_DEBUG
@@ -45,9 +41,35 @@ MODULE_DESCRIPTION("Promise SATA SX8 block driver");
 #undef CARM_NDEBUG
 
 #define DRV_NAME "sx8"
-#define DRV_VERSION "0.8"
+#define DRV_VERSION "1.0"
 #define PFX DRV_NAME ": "
 
+MODULE_AUTHOR("Jeff Garzik");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Promise SATA SX8 block driver");
+MODULE_VERSION(DRV_VERSION);
+
+/*
+ * SX8 hardware has a single message queue for all ATA ports.
+ * When this driver was written, the hardware (firmware?) would
+ * corrupt data eventually, if more than one request was outstanding.
+ * As one can imagine, having 8 ports bottlenecking on a single
+ * command hurts performance.
+ *
+ * Based on user reports, later versions of the hardware (firmware?)
+ * seem to be able to survive with more than one command queued.
+ *
+ * Therefore, we default to the safe option -- 1 command -- but
+ * allow the user to increase this.
+ *
+ * SX8 should be able to support up to ~60 queued commands (CARM_MAX_REQ),
+ * but problems seem to occur when you exceed ~30, even on newer hardware.
+ */
+static int max_queue = 1;
+module_param(max_queue, int, 0444);
+MODULE_PARM_DESC(max_queue, "Maximum number of queued commands. (min==1, max==30, safe==1)");
+
+
 #define NEXT_RESP(idx)  ((idx + 1) % RMSG_Q_LEN)
 
 /* 0xf is just arbitrary, non-zero noise; this is sorta like poisoning */
@@ -90,12 +112,10 @@ enum {
 
         /* command message queue limits */
         CARM_MAX_REQ            = 64,          /* max command msgs per host */
-        CARM_MAX_Q              = 1,               /* one command at a time */
         CARM_MSG_LOW_WATER      = (CARM_MAX_REQ / 4),        /* refill mark */
 
         /* S/G limits, host-wide and per-request */
         CARM_MAX_REQ_SG         = 32,        /* max s/g entries per request */
-        CARM_SG_BOUNDARY        = 0xffffUL,         /* s/g segment boundary */
         CARM_MAX_HOST_SG        = 600,          /* max s/g entries per host */
         CARM_SG_LOW_WATER       = (CARM_MAX_HOST_SG / 4),   /* re-fill mark */
 
@@ -181,6 +201,10 @@ enum {
         FL_DYN_MAJOR            = (1 << 17),
 };
 
+enum {
+        CARM_SG_BOUNDARY        = 0xffffUL,         /* s/g segment boundary */
+};
+
 enum scatter_gather_types {
         SGT_32BIT               = 0,
         SGT_64BIT               = 1,
@@ -218,7 +242,6 @@ static const char *state_name[] = {
 
 struct carm_port {
         unsigned int                    port_no;
-        unsigned int                    n_queued;
         struct gendisk                  *disk;
         struct carm_host                *host;
 
@@ -448,7 +471,7 @@ static inline int carm_lookup_bucket(u32 msg_size)
         for (i = 0; i < ARRAY_SIZE(msg_sizes); i++)
                 if (msg_size <= msg_sizes[i])
                         return i;
-        
+
         return -ENOENT;
 }
 
@@ -509,7 +532,7 @@ static struct carm_request *carm_get_request(struct carm_host *host)
         if (host->hw_sg_used >= (CARM_MAX_HOST_SG - CARM_MAX_REQ_SG))
                 return NULL;
 
-        for (i = 0; i < CARM_MAX_Q; i++)
+        for (i = 0; i < max_queue; i++)
                 if ((host->msg_alloc & (1ULL << i)) == 0) {
                         struct carm_request *crq = &host->req[i];
                         crq->port = NULL;
@@ -521,14 +544,14 @@ static struct carm_request *carm_get_request(struct carm_host *host)
                         assert(host->n_msgs <= CARM_MAX_REQ);
                         return crq;
                 }
-        
+
         DPRINTK("no request available, returning NULL\n");
         return NULL;
 }
 
 static int carm_put_request(struct carm_host *host, struct carm_request *crq)
 {
-        assert(crq->tag < CARM_MAX_Q);
+        assert(crq->tag < max_queue);
 
         if (unlikely((host->msg_alloc & (1ULL << crq->tag)) == 0))
                 return -EINVAL; /* tried to clear a tag that was not active */
@@ -791,7 +814,7 @@ static inline void carm_end_rq(struct carm_host *host, struct carm_request *crq,
                         int is_ok)
 {
         carm_end_request_queued(host, crq, is_ok);
-        if (CARM_MAX_Q == 1)
+        if (max_queue == 1)
                 carm_round_robin(host);
         else if ((host->n_msgs <= CARM_MSG_LOW_WATER) &&
                  (host->hw_sg_used <= CARM_SG_LOW_WATER)) {
diff --git a/drivers/block/ub.c b/drivers/block/ub.c
index ed4d5006fe62..bfb23d543ff7 100644
--- a/drivers/block/ub.c
+++ b/drivers/block/ub.c
@@ -1512,7 +1512,7 @@ static void ub_state_sense(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
         scmd->nsg = 1;
         sg = &scmd->sgv[0];
         sg->page = virt_to_page(sc->top_sense);
-        sg->offset = (unsigned int)sc->top_sense & (PAGE_SIZE-1);
+        sg->offset = (unsigned long)sc->top_sense & (PAGE_SIZE-1);
         sg->length = UB_SENSE_SIZE;
         scmd->len = UB_SENSE_SIZE;
         scmd->lun = cmd->lun;
@@ -1891,7 +1891,7 @@ static int ub_sync_read_cap(struct ub_dev *sc, struct ub_lun *lun,
         cmd->nsg = 1;
         sg = &cmd->sgv[0];
         sg->page = virt_to_page(p);
-        sg->offset = (unsigned int)p & (PAGE_SIZE-1);
+        sg->offset = (unsigned long)p & (PAGE_SIZE-1);
         sg->length = 8;
         cmd->len = 8;
         cmd->lun = lun;