nfs: new subdir Documentation/filesystems/nfs
[safe/jmp/linux-2.6] / block / as-iosched.c
index 640aa83..ce8ba57 100644 (file)
@@ -17,9 +17,6 @@
 #include <linux/rbtree.h>
 #include <linux/interrupt.h>
 
-#define REQ_SYNC       1
-#define REQ_ASYNC      0
-
 /*
  * See Documentation/block/as-iosched.txt
  */
@@ -93,7 +90,7 @@ struct as_data {
        struct list_head fifo_list[2];
 
        struct request *next_rq[2];     /* next in sort order */
-       sector_t last_sector[2];        /* last REQ_SYNC & REQ_ASYNC sectors */
+       sector_t last_sector[2];        /* last SYNC & ASYNC sectors */
 
        unsigned long exit_prob;        /* probability a task will exit while
                                           being waited on */
@@ -109,7 +106,7 @@ struct as_data {
        unsigned long last_check_fifo[2];
        int changed_batch;              /* 1: waiting for old batch to end */
        int new_batch;                  /* 1: waiting on first read complete */
-       int batch_data_dir;             /* current batch REQ_SYNC / REQ_ASYNC */
+       int batch_data_dir;             /* current batch SYNC / ASYNC */
        int write_batch_count;          /* max # of reqs in a write batch */
        int current_write_count;        /* how many requests left this batch */
        int write_batch_idled;          /* has the write batch gone idle? */
@@ -149,8 +146,9 @@ enum arq_state {
 #define RQ_STATE(rq)   ((enum arq_state)(rq)->elevator_private2)
 #define RQ_SET_STATE(rq, state)        ((rq)->elevator_private2 = (void *) state)
 
-static DEFINE_PER_CPU(unsigned long, ioc_count);
+static DEFINE_PER_CPU(unsigned long, as_ioc_count);
 static struct completion *ioc_gone;
+static DEFINE_SPINLOCK(ioc_gone_lock);
 
 static void as_move_to_dispatch(struct as_data *ad, struct request *rq);
 static void as_antic_stop(struct as_data *ad);
@@ -163,16 +161,29 @@ static void as_antic_stop(struct as_data *ad);
 static void free_as_io_context(struct as_io_context *aic)
 {
        kfree(aic);
-       elv_ioc_count_dec(ioc_count);
-       if (ioc_gone && !elv_ioc_count_read(ioc_count))
-               complete(ioc_gone);
+       elv_ioc_count_dec(as_ioc_count);
+       if (ioc_gone) {
+               /*
+                * AS scheduler is exiting, grab exit lock and check
+                * the pending io context count. If it hits zero,
+                * complete ioc_gone and set it back to NULL.
+                */
+               spin_lock(&ioc_gone_lock);
+               if (ioc_gone && !elv_ioc_count_read(as_ioc_count)) {
+                       complete(ioc_gone);
+                       ioc_gone = NULL;
+               }
+               spin_unlock(&ioc_gone_lock);
+       }
 }
 
 static void as_trim(struct io_context *ioc)
 {
+       spin_lock_irq(&ioc->lock);
        if (ioc->aic)
                free_as_io_context(ioc->aic);
        ioc->aic = NULL;
+       spin_unlock_irq(&ioc->lock);
 }
 
 /* Called when the task exits */
@@ -200,7 +211,7 @@ static struct as_io_context *alloc_as_io_context(void)
                ret->seek_total = 0;
                ret->seek_samples = 0;
                ret->seek_mean = 0;
-               elv_ioc_count_inc(ioc_count);
+               elv_ioc_count_inc(as_ioc_count);
        }
 
        return ret;
@@ -233,10 +244,12 @@ static void as_put_io_context(struct request *rq)
        aic = RQ_IOC(rq)->aic;
 
        if (rq_is_sync(rq) && aic) {
-               spin_lock(&aic->lock);
+               unsigned long flags;
+
+               spin_lock_irqsave(&aic->lock, flags);
                set_bit(AS_TASK_IORUNNING, &aic->state);
                aic->last_end_request = jiffies;
-               spin_unlock(&aic->lock);
+               spin_unlock_irqrestore(&aic->lock, flags);
        }
 
        put_io_context(RQ_IOC(rq));
@@ -293,8 +306,8 @@ as_choose_req(struct as_data *ad, struct request *rq1, struct request *rq2)
        data_dir = rq_is_sync(rq1);
 
        last = ad->last_sector[data_dir];
-       s1 = rq1->sector;
-       s2 = rq2->sector;
+       s1 = blk_rq_pos(rq1);
+       s2 = blk_rq_pos(rq2);
 
        BUG_ON(data_dir != rq_is_sync(rq2));
 
@@ -446,7 +459,7 @@ static void as_antic_stop(struct as_data *ad)
                        del_timer(&ad->antic_timer);
                ad->antic_status = ANTIC_FINISHED;
                /* see as_work_handler */
-               kblockd_schedule_work(&ad->antic_work);
+               kblockd_schedule_work(ad->q, &ad->antic_work);
        }
 }
 
@@ -462,10 +475,12 @@ static void as_antic_timeout(unsigned long data)
        spin_lock_irqsave(q->queue_lock, flags);
        if (ad->antic_status == ANTIC_WAIT_REQ
                        || ad->antic_status == ANTIC_WAIT_NEXT) {
-               struct as_io_context *aic = ad->io_context->aic;
+               struct as_io_context *aic;
+               spin_lock(&ad->io_context->lock);
+               aic = ad->io_context->aic;
 
                ad->antic_status = ANTIC_FINISHED;
-               kblockd_schedule_work(&ad->antic_work);
+               kblockd_schedule_work(q, &ad->antic_work);
 
                if (aic->ttime_samples == 0) {
                        /* process anticipated on has exited or timed out*/
@@ -475,6 +490,7 @@ static void as_antic_timeout(unsigned long data)
                        /* process not "saved" by a cooperating request */
                        ad->exit_no_coop = (7*ad->exit_no_coop + 256)/8;
                }
+               spin_unlock(&ad->io_context->lock);
        }
        spin_unlock_irqrestore(q->queue_lock, flags);
 }
@@ -535,7 +551,7 @@ static void as_update_iohist(struct as_data *ad, struct as_io_context *aic,
        if (aic == NULL)
                return;
 
-       if (data_dir == REQ_SYNC) {
+       if (data_dir == BLK_RW_SYNC) {
                unsigned long in_flight = atomic_read(&aic->nr_queued)
                                        + atomic_read(&aic->nr_dispatched);
                spin_lock(&aic->lock);
@@ -550,13 +566,15 @@ static void as_update_iohist(struct as_data *ad, struct as_io_context *aic,
                        as_update_thinktime(ad, aic, thinktime);
 
                        /* Calculate read -> read seek distance */
-                       if (aic->last_request_pos < rq->sector)
-                               seek_dist = rq->sector - aic->last_request_pos;
+                       if (aic->last_request_pos < blk_rq_pos(rq))
+                               seek_dist = blk_rq_pos(rq) -
+                                           aic->last_request_pos;
                        else
-                               seek_dist = aic->last_request_pos - rq->sector;
+                               seek_dist = aic->last_request_pos -
+                                           blk_rq_pos(rq);
                        as_update_seekdist(ad, aic, seek_dist);
                }
-               aic->last_request_pos = rq->sector + rq->nr_sectors;
+               aic->last_request_pos = blk_rq_pos(rq) + blk_rq_sectors(rq);
                set_bit(AS_TASK_IOSTARTED, &aic->state);
                spin_unlock(&aic->lock);
        }
@@ -571,7 +589,7 @@ static int as_close_req(struct as_data *ad, struct as_io_context *aic,
 {
        unsigned long delay;    /* jiffies */
        sector_t last = ad->last_sector[ad->batch_data_dir];
-       sector_t next = rq->sector;
+       sector_t next = blk_rq_pos(rq);
        sector_t delta; /* acceptable close offset (in sectors) */
        sector_t s;
 
@@ -635,9 +653,11 @@ static int as_can_break_anticipation(struct as_data *ad, struct request *rq)
 
        ioc = ad->io_context;
        BUG_ON(!ioc);
+       spin_lock(&ioc->lock);
 
        if (rq && ioc == RQ_IOC(rq)) {
                /* request from same process */
+               spin_unlock(&ioc->lock);
                return 1;
        }
 
@@ -646,20 +666,25 @@ static int as_can_break_anticipation(struct as_data *ad, struct request *rq)
                 * In this situation status should really be FINISHED,
                 * however the timer hasn't had the chance to run yet.
                 */
+               spin_unlock(&ioc->lock);
                return 1;
        }
 
        aic = ioc->aic;
-       if (!aic)
+       if (!aic) {
+               spin_unlock(&ioc->lock);
                return 0;
+       }
 
        if (atomic_read(&aic->nr_queued) > 0) {
                /* process has more requests queued */
+               spin_unlock(&ioc->lock);
                return 1;
        }
 
        if (atomic_read(&aic->nr_dispatched) > 0) {
                /* process has more requests dispatched */
+               spin_unlock(&ioc->lock);
                return 1;
        }
 
@@ -680,6 +705,7 @@ static int as_can_break_anticipation(struct as_data *ad, struct request *rq)
                }
 
                as_update_iohist(ad, aic, rq);
+               spin_unlock(&ioc->lock);
                return 1;
        }
 
@@ -688,20 +714,27 @@ static int as_can_break_anticipation(struct as_data *ad, struct request *rq)
                if (aic->ttime_samples == 0)
                        ad->exit_prob = (7*ad->exit_prob + 256)/8;
 
-               if (ad->exit_no_coop > 128)
+               if (ad->exit_no_coop > 128) {
+                       spin_unlock(&ioc->lock);
                        return 1;
+               }
        }
 
        if (aic->ttime_samples == 0) {
-               if (ad->new_ttime_mean > ad->antic_expire)
+               if (ad->new_ttime_mean > ad->antic_expire) {
+                       spin_unlock(&ioc->lock);
                        return 1;
-               if (ad->exit_prob * ad->exit_no_coop > 128*256)
+               }
+               if (ad->exit_prob * ad->exit_no_coop > 128*256) {
+                       spin_unlock(&ioc->lock);
                        return 1;
+               }
        } else if (aic->ttime_mean > ad->antic_expire) {
                /* the process thinks too much between requests */
+               spin_unlock(&ioc->lock);
                return 1;
        }
-
+       spin_unlock(&ioc->lock);
        return 0;
 }
 
@@ -711,6 +744,14 @@ static int as_can_break_anticipation(struct as_data *ad, struct request *rq)
  */
 static int as_can_anticipate(struct as_data *ad, struct request *rq)
 {
+#if 0 /* disable for now, we need to check tag level as well */
+       /*
+        * SSD device without seek penalty, disable idling
+        */
+       if (blk_queue_nonrot(ad->q)) axman
+               return 0;
+#endif
+
        if (!ad->io_context)
                /*
                 * Last request submitted was a write
@@ -769,7 +810,7 @@ static void as_update_rq(struct as_data *ad, struct request *rq)
  */
 static void update_write_batch(struct as_data *ad)
 {
-       unsigned long batch = ad->batch_expire[REQ_ASYNC];
+       unsigned long batch = ad->batch_expire[BLK_RW_ASYNC];
        long write_time;
 
        write_time = (jiffies - ad->current_batch_expires) + batch;
@@ -796,23 +837,24 @@ static void update_write_batch(struct as_data *ad)
  * as_completed_request is to be called when a request has completed and
  * returned something to the requesting process, be it an error or data.
  */
-static void as_completed_request(request_queue_t *q, struct request *rq)
+static void as_completed_request(struct request_queue *q, struct request *rq)
 {
        struct as_data *ad = q->elevator->elevator_data;
 
        WARN_ON(!list_empty(&rq->queuelist));
 
        if (RQ_STATE(rq) != AS_RQ_REMOVED) {
-               printk("rq->state %d\n", RQ_STATE(rq));
-               WARN_ON(1);
+               WARN(1, "rq->state %d\n", RQ_STATE(rq));
                goto out;
        }
 
        if (ad->changed_batch && ad->nr_dispatched == 1) {
-               kblockd_schedule_work(&ad->antic_work);
+               ad->current_batch_expires = jiffies +
+                                       ad->batch_expire[ad->batch_data_dir];
+               kblockd_schedule_work(q, &ad->antic_work);
                ad->changed_batch = 0;
 
-               if (ad->batch_data_dir == REQ_SYNC)
+               if (ad->batch_data_dir == BLK_RW_SYNC)
                        ad->new_batch = 1;
        }
        WARN_ON(ad->nr_dispatched == 0);
@@ -826,7 +868,7 @@ static void as_completed_request(request_queue_t *q, struct request *rq)
        if (ad->new_batch && ad->batch_data_dir == rq_is_sync(rq)) {
                update_write_batch(ad);
                ad->current_batch_expires = jiffies +
-                               ad->batch_expire[REQ_SYNC];
+                               ad->batch_expire[BLK_RW_SYNC];
                ad->new_batch = 0;
        }
 
@@ -853,7 +895,8 @@ out:
  * reference unless it replaces the request at somepart of the elevator
  * (ie. the dispatch queue)
  */
-static void as_remove_queued_request(request_queue_t *q, struct request *rq)
+static void as_remove_queued_request(struct request_queue *q,
+                                    struct request *rq)
 {
        const int data_dir = rq_is_sync(rq);
        struct as_data *ad = q->elevator->elevator_data;
@@ -879,7 +922,7 @@ static void as_remove_queued_request(request_queue_t *q, struct request *rq)
 }
 
 /*
- * as_fifo_expired returns 0 if there are no expired reads on the fifo,
+ * as_fifo_expired returns 0 if there are no expired requests 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
  * would create a hopeless seekstorm.
@@ -916,7 +959,7 @@ static inline int as_batch_expired(struct as_data *ad)
        if (ad->changed_batch || ad->new_batch)
                return 0;
 
-       if (ad->batch_data_dir == REQ_SYNC)
+       if (ad->batch_data_dir == BLK_RW_SYNC)
                /* TODO! add a check so a complete fifo gets written? */
                return time_after(jiffies, ad->current_batch_expires);
 
@@ -940,9 +983,9 @@ static void as_move_to_dispatch(struct as_data *ad, struct request *rq)
         * This has to be set in order to be correctly updated by
         * as_find_next_rq
         */
-       ad->last_sector[data_dir] = rq->sector + rq->nr_sectors;
+       ad->last_sector[data_dir] = blk_rq_pos(rq) + blk_rq_sectors(rq);
 
-       if (data_dir == REQ_SYNC) {
+       if (data_dir == BLK_RW_SYNC) {
                struct io_context *ioc = RQ_IOC(rq);
                /* In case we have to anticipate after this */
                copy_io_context(&ad->io_context, &ioc);
@@ -978,44 +1021,44 @@ static void as_move_to_dispatch(struct as_data *ad, struct request *rq)
  * 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(request_queue_t *q, int force)
+static int as_dispatch_request(struct request_queue *q, int force)
 {
        struct as_data *ad = q->elevator->elevator_data;
-       const int reads = !list_empty(&ad->fifo_list[REQ_SYNC]);
-       const int writes = !list_empty(&ad->fifo_list[REQ_ASYNC]);
+       const int reads = !list_empty(&ad->fifo_list[BLK_RW_SYNC]);
+       const int writes = !list_empty(&ad->fifo_list[BLK_RW_ASYNC]);
        struct request *rq;
 
        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
+                * batch_data_dir is reset to BLK_RW_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->batch_data_dir = BLK_RW_SYNC;
                ad->changed_batch = 0;
                ad->new_batch = 0;
 
-               while (ad->next_rq[REQ_SYNC]) {
-                       as_move_to_dispatch(ad, ad->next_rq[REQ_SYNC]);
+               while (ad->next_rq[BLK_RW_SYNC]) {
+                       as_move_to_dispatch(ad, ad->next_rq[BLK_RW_SYNC]);
                        dispatched++;
                }
-               ad->last_check_fifo[REQ_SYNC] = jiffies;
+               ad->last_check_fifo[BLK_RW_SYNC] = jiffies;
 
-               while (ad->next_rq[REQ_ASYNC]) {
-                       as_move_to_dispatch(ad, ad->next_rq[REQ_ASYNC]);
+               while (ad->next_rq[BLK_RW_ASYNC]) {
+                       as_move_to_dispatch(ad, ad->next_rq[BLK_RW_ASYNC]);
                        dispatched++;
                }
-               ad->last_check_fifo[REQ_ASYNC] = jiffies;
+               ad->last_check_fifo[BLK_RW_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->batch_data_dir == BLK_RW_ASYNC && !reads) {
                if (ad->current_write_count == 0 || !writes)
                        ad->write_batch_idled = 1;
        }
@@ -1032,8 +1075,8 @@ static int as_dispatch_request(request_queue_t *q, int force)
                 */
                rq = ad->next_rq[ad->batch_data_dir];
 
-               if (ad->batch_data_dir == REQ_SYNC && ad->antic_expire) {
-                       if (as_fifo_expired(ad, REQ_SYNC))
+               if (ad->batch_data_dir == BLK_RW_SYNC && ad->antic_expire) {
+                       if (as_fifo_expired(ad, BLK_RW_SYNC))
                                goto fifo_expired;
 
                        if (as_can_anticipate(ad, rq)) {
@@ -1046,7 +1089,7 @@ static int as_dispatch_request(request_queue_t *q, int force)
                        /* we have a "next request" */
                        if (reads && !writes)
                                ad->current_batch_expires =
-                                       jiffies + ad->batch_expire[REQ_SYNC];
+                                       jiffies + ad->batch_expire[BLK_RW_SYNC];
                        goto dispatch_request;
                }
        }
@@ -1057,20 +1100,20 @@ static int as_dispatch_request(request_queue_t *q, int force)
         */
 
        if (reads) {
-               BUG_ON(RB_EMPTY_ROOT(&ad->sort_list[REQ_SYNC]));
+               BUG_ON(RB_EMPTY_ROOT(&ad->sort_list[BLK_RW_SYNC]));
 
-               if (writes && ad->batch_data_dir == REQ_SYNC)
+               if (writes && ad->batch_data_dir == BLK_RW_SYNC)
                        /*
                         * Last batch was a read, switch to writes
                         */
                        goto dispatch_writes;
 
-               if (ad->batch_data_dir == REQ_ASYNC) {
+               if (ad->batch_data_dir == BLK_RW_ASYNC) {
                        WARN_ON(ad->new_batch);
                        ad->changed_batch = 1;
                }
-               ad->batch_data_dir = REQ_SYNC;
-               rq = rq_entry_fifo(ad->fifo_list[REQ_SYNC].next);
+               ad->batch_data_dir = BLK_RW_SYNC;
+               rq = rq_entry_fifo(ad->fifo_list[BLK_RW_SYNC].next);
                ad->last_check_fifo[ad->batch_data_dir] = jiffies;
                goto dispatch_request;
        }
@@ -1081,9 +1124,9 @@ static int as_dispatch_request(request_queue_t *q, int force)
 
        if (writes) {
 dispatch_writes:
-               BUG_ON(RB_EMPTY_ROOT(&ad->sort_list[REQ_ASYNC]));
+               BUG_ON(RB_EMPTY_ROOT(&ad->sort_list[BLK_RW_ASYNC]));
 
-               if (ad->batch_data_dir == REQ_SYNC) {
+               if (ad->batch_data_dir == BLK_RW_SYNC) {
                        ad->changed_batch = 1;
 
                        /*
@@ -1093,10 +1136,11 @@ dispatch_writes:
                         */
                        ad->new_batch = 0;
                }
-               ad->batch_data_dir = REQ_ASYNC;
+               ad->batch_data_dir = BLK_RW_ASYNC;
                ad->current_write_count = ad->write_batch_count;
                ad->write_batch_idled = 0;
-               rq = ad->next_rq[ad->batch_data_dir];
+               rq = rq_entry_fifo(ad->fifo_list[BLK_RW_ASYNC].next);
+               ad->last_check_fifo[BLK_RW_ASYNC] = jiffies;
                goto dispatch_request;
        }
 
@@ -1119,9 +1163,9 @@ fifo_expired:
                if (ad->nr_dispatched)
                        return 0;
 
-               if (ad->batch_data_dir == REQ_ASYNC)
+               if (ad->batch_data_dir == BLK_RW_ASYNC)
                        ad->current_batch_expires = jiffies +
-                                       ad->batch_expire[REQ_ASYNC];
+                                       ad->batch_expire[BLK_RW_ASYNC];
                else
                        ad->new_batch = 1;
 
@@ -1139,7 +1183,7 @@ fifo_expired:
 /*
  * add rq to rbtree and fifo
  */
-static void as_add_request(request_queue_t *q, struct request *rq)
+static void as_add_request(struct request_queue *q, struct request *rq)
 {
        struct as_data *ad = q->elevator->elevator_data;
        int data_dir;
@@ -1158,7 +1202,7 @@ static void as_add_request(request_queue_t *q, struct request *rq)
        as_add_rq_rb(ad, rq);
 
        /*
-        * set expire time (only used for reads) and add to fifo list
+        * set expire time and add to fifo list
         */
        rq_set_fifo_time(rq, jiffies + ad->fifo_expire[data_dir]);
        list_add_tail(&rq->queuelist, &ad->fifo_list[data_dir]);
@@ -1167,7 +1211,7 @@ static void as_add_request(request_queue_t *q, struct request *rq)
        RQ_SET_STATE(rq, AS_RQ_QUEUED);
 }
 
-static void as_activate_request(request_queue_t *q, struct request *rq)
+static void as_activate_request(struct request_queue *q, struct request *rq)
 {
        WARN_ON(RQ_STATE(rq) != AS_RQ_DISPATCHED);
        RQ_SET_STATE(rq, AS_RQ_REMOVED);
@@ -1175,7 +1219,7 @@ static void as_activate_request(request_queue_t *q, struct request *rq)
                atomic_dec(&RQ_IOC(rq)->aic->nr_dispatched);
 }
 
-static void as_deactivate_request(request_queue_t *q, struct request *rq)
+static void as_deactivate_request(struct request_queue *q, struct request *rq)
 {
        WARN_ON(RQ_STATE(rq) != AS_RQ_REMOVED);
        RQ_SET_STATE(rq, AS_RQ_DISPATCHED);
@@ -1189,16 +1233,16 @@ static void as_deactivate_request(request_queue_t *q, struct request *rq)
  * is not empty - it is used in the block layer to check for plugging and
  * merging opportunities
  */
-static int as_queue_empty(request_queue_t *q)
+static int as_queue_empty(struct request_queue *q)
 {
        struct as_data *ad = q->elevator->elevator_data;
 
-       return list_empty(&ad->fifo_list[REQ_ASYNC])
-               && list_empty(&ad->fifo_list[REQ_SYNC]);
+       return list_empty(&ad->fifo_list[BLK_RW_ASYNC])
+               && list_empty(&ad->fifo_list[BLK_RW_SYNC]);
 }
 
 static int
-as_merge(request_queue_t *q, struct request **req, struct bio *bio)
+as_merge(struct request_queue *q, struct request **req, struct bio *bio)
 {
        struct as_data *ad = q->elevator->elevator_data;
        sector_t rb_key = bio->bi_sector + bio_sectors(bio);
@@ -1216,7 +1260,8 @@ as_merge(request_queue_t *q, struct request **req, struct bio *bio)
        return ELEVATOR_NO_MERGE;
 }
 
-static void as_merged_request(request_queue_t *q, struct request *req, int type)
+static void as_merged_request(struct request_queue *q, struct request *req,
+                             int type)
 {
        struct as_data *ad = q->elevator->elevator_data;
 
@@ -1234,7 +1279,7 @@ static void as_merged_request(request_queue_t *q, struct request *req, int type)
        }
 }
 
-static void as_merged_requests(request_queue_t *q, struct request *req,
+static void as_merged_requests(struct request_queue *q, struct request *req,
                                struct request *next)
 {
        /*
@@ -1243,16 +1288,8 @@ static void as_merged_requests(request_queue_t *q, struct request *req,
         */
        if (!list_empty(&req->queuelist) && !list_empty(&next->queuelist)) {
                if (time_before(rq_fifo_time(next), rq_fifo_time(req))) {
-                       struct io_context *rioc = RQ_IOC(req);
-                       struct io_context *nioc = RQ_IOC(next);
-
                        list_move(&req->queuelist, &next->queuelist);
                        rq_set_fifo_time(req, rq_fifo_time(next));
-                       /*
-                        * Don't copy here but swap, because when anext is
-                        * removed below, it must contain the unused context
-                        */
-                       swap_io_context(&rioc, &nioc);
                }
        }
 
@@ -1277,15 +1314,11 @@ static void as_merged_requests(request_queue_t *q, struct request *req,
 static void as_work_handler(struct work_struct *work)
 {
        struct as_data *ad = container_of(work, struct as_data, antic_work);
-       struct request_queue *q = ad->q;
-       unsigned long flags;
 
-       spin_lock_irqsave(q->queue_lock, flags);
-       blk_start_queueing(q);
-       spin_unlock_irqrestore(q->queue_lock, flags);
+       blk_run_queue(ad->q);
 }
 
-static int as_may_queue(request_queue_t *q, int rw)
+static int as_may_queue(struct request_queue *q, int rw)
 {
        int ret = ELV_MQUEUE_MAY;
        struct as_data *ad = q->elevator->elevator_data;
@@ -1301,15 +1334,15 @@ static int as_may_queue(request_queue_t *q, int rw)
        return ret;
 }
 
-static void as_exit_queue(elevator_t *e)
+static void as_exit_queue(struct elevator_queue *e)
 {
        struct as_data *ad = e->elevator_data;
 
        del_timer_sync(&ad->antic_timer);
-       kblockd_flush();
+       cancel_work_sync(&ad->antic_work);
 
-       BUG_ON(!list_empty(&ad->fifo_list[REQ_SYNC]));
-       BUG_ON(!list_empty(&ad->fifo_list[REQ_ASYNC]));
+       BUG_ON(!list_empty(&ad->fifo_list[BLK_RW_SYNC]));
+       BUG_ON(!list_empty(&ad->fifo_list[BLK_RW_ASYNC]));
 
        put_io_context(ad->io_context);
        kfree(ad);
@@ -1318,14 +1351,13 @@ static void as_exit_queue(elevator_t *e)
 /*
  * initialize elevator private data (as_data).
  */
-static void *as_init_queue(request_queue_t *q)
+static void *as_init_queue(struct request_queue *q)
 {
        struct as_data *ad;
 
-       ad = kmalloc_node(sizeof(*ad), GFP_KERNEL, q->node);
+       ad = kmalloc_node(sizeof(*ad), GFP_KERNEL | __GFP_ZERO, q->node);
        if (!ad)
                return NULL;
-       memset(ad, 0, sizeof(*ad));
 
        ad->q = q; /* Identify what queue the data belongs to */
 
@@ -1335,18 +1367,18 @@ static void *as_init_queue(request_queue_t *q)
        init_timer(&ad->antic_timer);
        INIT_WORK(&ad->antic_work, as_work_handler);
 
-       INIT_LIST_HEAD(&ad->fifo_list[REQ_SYNC]);
-       INIT_LIST_HEAD(&ad->fifo_list[REQ_ASYNC]);
-       ad->sort_list[REQ_SYNC] = RB_ROOT;
-       ad->sort_list[REQ_ASYNC] = RB_ROOT;
-       ad->fifo_expire[REQ_SYNC] = default_read_expire;
-       ad->fifo_expire[REQ_ASYNC] = default_write_expire;
+       INIT_LIST_HEAD(&ad->fifo_list[BLK_RW_SYNC]);
+       INIT_LIST_HEAD(&ad->fifo_list[BLK_RW_ASYNC]);
+       ad->sort_list[BLK_RW_SYNC] = RB_ROOT;
+       ad->sort_list[BLK_RW_ASYNC] = RB_ROOT;
+       ad->fifo_expire[BLK_RW_SYNC] = default_read_expire;
+       ad->fifo_expire[BLK_RW_ASYNC] = default_write_expire;
        ad->antic_expire = default_antic_expire;
-       ad->batch_expire[REQ_SYNC] = default_read_batch_expire;
-       ad->batch_expire[REQ_ASYNC] = default_write_batch_expire;
+       ad->batch_expire[BLK_RW_SYNC] = default_read_batch_expire;
+       ad->batch_expire[BLK_RW_ASYNC] = default_write_batch_expire;
 
-       ad->current_batch_expires = jiffies + ad->batch_expire[REQ_SYNC];
-       ad->write_batch_count = ad->batch_expire[REQ_ASYNC] / 10;
+       ad->current_batch_expires = jiffies + ad->batch_expire[BLK_RW_SYNC];
+       ad->write_batch_count = ad->batch_expire[BLK_RW_ASYNC] / 10;
        if (ad->write_batch_count < 2)
                ad->write_batch_count = 2;
 
@@ -1372,7 +1404,7 @@ as_var_store(unsigned long *var, const char *page, size_t count)
        return count;
 }
 
-static ssize_t est_time_show(elevator_t *e, char *page)
+static ssize_t est_time_show(struct elevator_queue *e, char *page)
 {
        struct as_data *ad = e->elevator_data;
        int pos = 0;
@@ -1390,20 +1422,20 @@ static ssize_t est_time_show(elevator_t *e, char *page)
 }
 
 #define SHOW_FUNCTION(__FUNC, __VAR)                           \
-static ssize_t __FUNC(elevator_t *e, char *page)               \
+static ssize_t __FUNC(struct elevator_queue *e, char *page)    \
 {                                                              \
        struct as_data *ad = e->elevator_data;                  \
        return as_var_show(jiffies_to_msecs((__VAR)), (page));  \
 }
-SHOW_FUNCTION(as_read_expire_show, ad->fifo_expire[REQ_SYNC]);
-SHOW_FUNCTION(as_write_expire_show, ad->fifo_expire[REQ_ASYNC]);
+SHOW_FUNCTION(as_read_expire_show, ad->fifo_expire[BLK_RW_SYNC]);
+SHOW_FUNCTION(as_write_expire_show, ad->fifo_expire[BLK_RW_ASYNC]);
 SHOW_FUNCTION(as_antic_expire_show, ad->antic_expire);
-SHOW_FUNCTION(as_read_batch_expire_show, ad->batch_expire[REQ_SYNC]);
-SHOW_FUNCTION(as_write_batch_expire_show, ad->batch_expire[REQ_ASYNC]);
+SHOW_FUNCTION(as_read_batch_expire_show, ad->batch_expire[BLK_RW_SYNC]);
+SHOW_FUNCTION(as_write_batch_expire_show, ad->batch_expire[BLK_RW_ASYNC]);
 #undef SHOW_FUNCTION
 
 #define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX)                                \
-static ssize_t __FUNC(elevator_t *e, const char *page, size_t count)   \
+static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count)        \
 {                                                                      \
        struct as_data *ad = e->elevator_data;                          \
        int ret = as_var_store(__PTR, (page), count);                   \
@@ -1414,13 +1446,14 @@ static ssize_t __FUNC(elevator_t *e, const char *page, size_t count)    \
        *(__PTR) = msecs_to_jiffies(*(__PTR));                          \
        return ret;                                                     \
 }
-STORE_FUNCTION(as_read_expire_store, &ad->fifo_expire[REQ_SYNC], 0, INT_MAX);
-STORE_FUNCTION(as_write_expire_store, &ad->fifo_expire[REQ_ASYNC], 0, INT_MAX);
+STORE_FUNCTION(as_read_expire_store, &ad->fifo_expire[BLK_RW_SYNC], 0, INT_MAX);
+STORE_FUNCTION(as_write_expire_store,
+                       &ad->fifo_expire[BLK_RW_ASYNC], 0, INT_MAX);
 STORE_FUNCTION(as_antic_expire_store, &ad->antic_expire, 0, INT_MAX);
 STORE_FUNCTION(as_read_batch_expire_store,
-                       &ad->batch_expire[REQ_SYNC], 0, INT_MAX);
+                       &ad->batch_expire[BLK_RW_SYNC], 0, INT_MAX);
 STORE_FUNCTION(as_write_batch_expire_store,
-                       &ad->batch_expire[REQ_ASYNC], 0, INT_MAX);
+                       &ad->batch_expire[BLK_RW_ASYNC], 0, INT_MAX);
 #undef STORE_FUNCTION
 
 #define AS_ATTR(name) \
@@ -1462,7 +1495,9 @@ static struct elevator_type iosched_as = {
 
 static int __init as_init(void)
 {
-       return elv_register(&iosched_as);
+       elv_register(&iosched_as);
+
+       return 0;
 }
 
 static void __exit as_exit(void)
@@ -1472,8 +1507,8 @@ static void __exit as_exit(void)
        ioc_gone = &all_gone;
        /* ioc_gone's update must be visible before reading ioc_count */
        smp_wmb();
-       if (elv_ioc_count_read(ioc_count))
-               wait_for_completion(ioc_gone);
+       if (elv_ioc_count_read(as_ioc_count))
+               wait_for_completion(&all_gone);
        synchronize_rcu();
 }