1 files changed, 282 insertions, 585 deletions

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 3a3aee08ec5f..d3d76136f53a 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -4,7 +4,7 @@
  *  Based on ideas from a previously unfinished io
  *  scheduler (round robin per-process disk scheduling) and Andrea Arcangeli.
  *
- *  Copyright (C) 2003 Jens Axboe <axboe@suse.de>
+ *  Copyright (C) 2003 Jens Axboe <axboe@kernel.dk>
  */
 #include <linux/module.h>
 #include <linux/blkdev.h>
@@ -17,7 +17,6 @@
  * tunables
  */
 static const int cfq_quantum = 4;               /* max queue in one round of service */
-static const int cfq_queued = 8;                /* minimum rq allocate limit per-queue*/
 static const int cfq_fifo_expire[2] = { HZ / 4, HZ / 8 };
 static const int cfq_back_max = 16 * 1024;      /* maximum backwards seek, in KiB */
 static const int cfq_back_penalty = 2;          /* penalty of a backwards seek */
@@ -32,8 +31,6 @@ static int cfq_slice_idle = HZ / 125;
 
 #define CFQ_KEY_ASYNC           (0)
 
-static DEFINE_SPINLOCK(cfq_exit_lock);
-
 /*
  * for the hash of cfqq inside the cfqd
  */
@@ -41,37 +38,19 @@ static DEFINE_SPINLOCK(cfq_exit_lock);
 #define CFQ_QHASH_ENTRIES       (1 << CFQ_QHASH_SHIFT)
 #define list_entry_qhash(entry) hlist_entry((entry), struct cfq_queue, cfq_hash)
 
-/*
- * for the hash of crq inside the cfqq
- */
-#define CFQ_MHASH_SHIFT         6
-#define CFQ_MHASH_BLOCK(sec)    ((sec) >> 3)
-#define CFQ_MHASH_ENTRIES       (1 << CFQ_MHASH_SHIFT)
-#define CFQ_MHASH_FN(sec)       hash_long(CFQ_MHASH_BLOCK(sec), CFQ_MHASH_SHIFT)
-#define rq_hash_key(rq)         ((rq)->sector + (rq)->nr_sectors)
-#define list_entry_hash(ptr)    hlist_entry((ptr), struct cfq_rq, hash)
-
 #define list_entry_cfqq(ptr)    list_entry((ptr), struct cfq_queue, cfq_list)
-#define list_entry_fifo(ptr)    list_entry((ptr), struct request, queuelist)
 
-#define RQ_DATA(rq)             (rq)->elevator_private
+#define RQ_CIC(rq)              ((struct cfq_io_context*)(rq)->elevator_private)
+#define RQ_CFQQ(rq)             ((rq)->elevator_private2)
 
-/*
- * rb-tree defines
- */
-#define rb_entry_crq(node)      rb_entry((node), struct cfq_rq, rb_node)
-#define rq_rb_key(rq)           (rq)->sector
-
-static kmem_cache_t *crq_pool;
 static kmem_cache_t *cfq_pool;
 static kmem_cache_t *cfq_ioc_pool;
 
-static atomic_t ioc_count = ATOMIC_INIT(0);
+static DEFINE_PER_CPU(unsigned long, ioc_count);
 static struct completion *ioc_gone;
 
 #define CFQ_PRIO_LISTS          IOPRIO_BE_NR
 #define cfq_class_idle(cfqq)    ((cfqq)->ioprio_class == IOPRIO_CLASS_IDLE)
-#define cfq_class_be(cfqq)      ((cfqq)->ioprio_class == IOPRIO_CLASS_BE)
 #define cfq_class_rt(cfqq)      ((cfqq)->ioprio_class == IOPRIO_CLASS_RT)
 
 #define ASYNC                   (0)
@@ -103,29 +82,14 @@ struct cfq_data {
         unsigned int busy_queues;
 
         /*
-         * non-ordered list of empty cfqq's
-         */
-        struct list_head empty_list;
-
-        /*
          * cfqq lookup hash
          */
         struct hlist_head *cfq_hash;
 
-        /*
-         * global crq hash for all queues
-         */
-        struct hlist_head *crq_hash;
-
-        mempool_t *crq_pool;
-
         int rq_in_driver;
         int hw_tag;
 
         /*
-         * schedule slice state info
-         */
-        /*
          * idle window management
          */
         struct timer_list idle_slice_timer;
@@ -141,13 +105,10 @@ struct cfq_data {
         sector_t last_sector;
         unsigned long last_end_request;
 
-        unsigned int rq_starved;
-
         /*
          * tunables, see top of file
          */
         unsigned int cfq_quantum;
-        unsigned int cfq_queued;
         unsigned int cfq_fifo_expire[2];
         unsigned int cfq_back_penalty;
         unsigned int cfq_back_max;
@@ -170,23 +131,24 @@ struct cfq_queue {
         struct hlist_node cfq_hash;
         /* hash key */
         unsigned int key;
-        /* on either rr or empty list of cfqd */
+        /* member of the rr/busy/cur/idle cfqd list */
         struct list_head cfq_list;
         /* sorted list of pending requests */
         struct rb_root sort_list;
         /* if fifo isn't expired, next request to serve */
-        struct cfq_rq *next_crq;
+        struct request *next_rq;
         /* requests queued in sort_list */
         int queued[2];
         /* currently allocated requests */
         int allocated[2];
+        /* pending metadata requests */
+        int meta_pending;
         /* fifo list of requests in sort_list */
         struct list_head fifo;
 
         unsigned long slice_start;
         unsigned long slice_end;
         unsigned long slice_left;
-        unsigned long service_last;
 
         /* number of requests that are on the dispatch list */
         int on_dispatch[2];
@@ -199,18 +161,6 @@ struct cfq_queue {
         unsigned int flags;
 };
 
-struct cfq_rq {
-        struct rb_node rb_node;
-        sector_t rb_key;
-        struct request *request;
-        struct hlist_node hash;
-
-        struct cfq_queue *cfq_queue;
-        struct cfq_io_context *io_context;
-
-        unsigned int crq_flags;
-};
-
 enum cfqq_state_flags {
         CFQ_CFQQ_FLAG_on_rr = 0,
         CFQ_CFQQ_FLAG_wait_request,
@@ -220,6 +170,7 @@ enum cfqq_state_flags {
         CFQ_CFQQ_FLAG_fifo_expire,
         CFQ_CFQQ_FLAG_idle_window,
         CFQ_CFQQ_FLAG_prio_changed,
+        CFQ_CFQQ_FLAG_queue_new,
 };
 
 #define CFQ_CFQQ_FNS(name)                                              \
@@ -244,70 +195,14 @@ CFQ_CFQQ_FNS(must_dispatch);
 CFQ_CFQQ_FNS(fifo_expire);
 CFQ_CFQQ_FNS(idle_window);
 CFQ_CFQQ_FNS(prio_changed);
+CFQ_CFQQ_FNS(queue_new);
 #undef CFQ_CFQQ_FNS
 
-enum cfq_rq_state_flags {
-        CFQ_CRQ_FLAG_is_sync = 0,
-};
-
-#define CFQ_CRQ_FNS(name)                                               \
-static inline void cfq_mark_crq_##name(struct cfq_rq *crq)              \
-{                                                                       \
-        crq->crq_flags |= (1 << CFQ_CRQ_FLAG_##name);                   \
-}                                                                       \
-static inline void cfq_clear_crq_##name(struct cfq_rq *crq)             \
-{                                                                       \
-        crq->crq_flags &= ~(1 << CFQ_CRQ_FLAG_##name);                  \
-}                                                                       \
-static inline int cfq_crq_##name(const struct cfq_rq *crq)              \
-{                                                                       \
-        return (crq->crq_flags & (1 << CFQ_CRQ_FLAG_##name)) != 0;      \
-}
-
-CFQ_CRQ_FNS(is_sync);
-#undef CFQ_CRQ_FNS
-
 static struct cfq_queue *cfq_find_cfq_hash(struct cfq_data *, unsigned int, unsigned short);
-static void cfq_dispatch_insert(request_queue_t *, struct cfq_rq *);
+static void cfq_dispatch_insert(request_queue_t *, struct request *);
 static struct cfq_queue *cfq_get_queue(struct cfq_data *cfqd, unsigned int key, struct task_struct *tsk, gfp_t gfp_mask);
 
 /*
- * lots of deadline iosched dupes, can be abstracted later...
- */
-static inline void cfq_del_crq_hash(struct cfq_rq *crq)
-{
-        hlist_del_init(&crq->hash);
-}
-
-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));
-
-        hlist_add_head(&crq->hash, &cfqd->crq_hash[hash_idx]);
-}
-
-static struct request *cfq_find_rq_hash(struct cfq_data *cfqd, sector_t offset)
-{
-        struct hlist_head *hash_list = &cfqd->crq_hash[CFQ_MHASH_FN(offset)];
-        struct hlist_node *entry, *next;
-
-        hlist_for_each_safe(entry, next, hash_list) {
-                struct cfq_rq *crq = list_entry_hash(entry);
-                struct request *__rq = crq->request;
-
-                if (!rq_mergeable(__rq)) {
-                        cfq_del_crq_hash(crq);
-                        continue;
-                }
-
-                if (rq_hash_key(__rq) == offset)
-                        return __rq;
-        }
-
-        return NULL;
-}
-
-/*
  * scheduler run of queue, if there are requests pending and no one in the
  * driver that will restart queueing
  */
@@ -333,12 +228,12 @@ static inline pid_t cfq_queue_pid(struct task_struct *task, int rw)
 }
 
 /*
- * Lifted from AS - choose which of crq1 and crq2 that is best served now.
+ * Lifted from AS - choose which of rq1 and rq2 that is best served now.
  * We choose the request that is closest to the head right now. Distance
  * behind the head is penalized and only allowed to a certain extent.
  */
-static struct cfq_rq *
-cfq_choose_req(struct cfq_data *cfqd, struct cfq_rq *crq1, struct cfq_rq *crq2)
+static struct request *
+cfq_choose_req(struct cfq_data *cfqd, struct request *rq1, struct request *rq2)
 {
         sector_t last, s1, s2, d1 = 0, d2 = 0;
         unsigned long back_max;
@@ -346,18 +241,22 @@ cfq_choose_req(struct cfq_data *cfqd, struct cfq_rq *crq1, struct cfq_rq *crq2)
 #define CFQ_RQ2_WRAP    0x02 /* request 2 wraps */
         unsigned wrap = 0; /* bit mask: requests behind the disk head? */
 
-        if (crq1 == NULL || crq1 == crq2)
-                return crq2;
-        if (crq2 == NULL)
-                return crq1;
+        if (rq1 == NULL || rq1 == rq2)
+                return rq2;
+        if (rq2 == NULL)
+                return rq1;
 
-        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))
-                return crq2;
+        if (rq_is_sync(rq1) && !rq_is_sync(rq2))
+                return rq1;
+        else if (rq_is_sync(rq2) && !rq_is_sync(rq1))
+                return rq2;
+        if (rq_is_meta(rq1) && !rq_is_meta(rq2))
+                return rq1;
+        else if (rq_is_meta(rq2) && !rq_is_meta(rq1))
+                return rq2;
 
-        s1 = crq1->request->sector;
-        s2 = crq2->request->sector;
+        s1 = rq1->sector;
+        s2 = rq2->sector;
 
         last = cfqd->last_sector;
 
@@ -392,23 +291,23 @@ cfq_choose_req(struct cfq_data *cfqd, struct cfq_rq *crq1, struct cfq_rq *crq2)
          * check two variables for all permutations: --> faster!
          */
         switch (wrap) {
-        case 0: /* common case for CFQ: crq1 and crq2 not wrapped */
+        case 0: /* common case for CFQ: rq1 and rq2 not wrapped */
                 if (d1 < d2)
-                        return crq1;
+                        return rq1;
                 else if (d2 < d1)
-                        return crq2;
+                        return rq2;
                 else {
                         if (s1 >= s2)
-                                return crq1;
+                                return rq1;
                         else
-                                return crq2;
+                                return rq2;
                 }
 
         case CFQ_RQ2_WRAP:
-                return crq1;
+                return rq1;
         case CFQ_RQ1_WRAP:
-                return crq2;
-        case (CFQ_RQ1_WRAP|CFQ_RQ2_WRAP): /* both crqs wrapped */
+                return rq2;
+        case (CFQ_RQ1_WRAP|CFQ_RQ2_WRAP): /* both rqs wrapped */
         default:
                 /*
                  * Since both rqs are wrapped,
@@ -417,50 +316,43 @@ cfq_choose_req(struct cfq_data *cfqd, struct cfq_rq *crq1, struct cfq_rq *crq2)
                  * since back seek takes more time than forward.
                  */
                 if (s1 <= s2)
-                        return crq1;
+                        return rq1;
                 else
-                        return crq2;
+                        return rq2;
         }
 }
 
 /*
  * would be nice to take fifo expire time into account as well
  */
-static struct cfq_rq *
-cfq_find_next_crq(struct cfq_data *cfqd, struct cfq_queue *cfqq,
-                  struct cfq_rq *last)
+static struct request *
+cfq_find_next_rq(struct cfq_data *cfqd, struct cfq_queue *cfqq,
+                  struct request *last)
 {
-        struct cfq_rq *crq_next = NULL, *crq_prev = NULL;
-        struct rb_node *rbnext, *rbprev;
-
-        if (!(rbnext = rb_next(&last->rb_node))) {
-                rbnext = rb_first(&cfqq->sort_list);
-                if (rbnext == &last->rb_node)
-                        rbnext = NULL;
-        }
+        struct rb_node *rbnext = rb_next(&last->rb_node);
+        struct rb_node *rbprev = rb_prev(&last->rb_node);
+        struct request *next = NULL, *prev = NULL;
 
-        rbprev = rb_prev(&last->rb_node);
+        BUG_ON(RB_EMPTY_NODE(&last->rb_node));
 
         if (rbprev)
-                crq_prev = rb_entry_crq(rbprev);
-        if (rbnext)
-                crq_next = rb_entry_crq(rbnext);
-
-        return cfq_choose_req(cfqd, crq_next, crq_prev);
-}
+                prev = rb_entry_rq(rbprev);
 
-static void cfq_update_next_crq(struct cfq_rq *crq)
-{
-        struct cfq_queue *cfqq = crq->cfq_queue;
+        if (rbnext)
+                next = rb_entry_rq(rbnext);
+        else {
+                rbnext = rb_first(&cfqq->sort_list);
+                if (rbnext && rbnext != &last->rb_node)
+                        next = rb_entry_rq(rbnext);
+        }
 
-        if (cfqq->next_crq == crq)
-                cfqq->next_crq = cfq_find_next_crq(cfqq->cfqd, cfqq, crq);
+        return cfq_choose_req(cfqd, next, prev);
 }
 
 static void cfq_resort_rr_list(struct cfq_queue *cfqq, int preempted)
 {
         struct cfq_data *cfqd = cfqq->cfqd;
-        struct list_head *list, *entry;
+        struct list_head *list;
 
         BUG_ON(!cfq_cfqq_on_rr(cfqq));
 
@@ -485,31 +377,26 @@ static void cfq_resort_rr_list(struct cfq_queue *cfqq, int preempted)
         }
 
         /*
-         * if queue was preempted, just add to front to be fair. busy_rr
-         * isn't sorted, but insert at the back for fairness.
+         * If this queue was preempted or is new (never been serviced), let
+         * it be added first for fairness but beind other new queues.
+         * Otherwise, just add to the back  of the list.
          */
-        if (preempted || list == &cfqd->busy_rr) {
-                if (preempted)
-                        list = list->prev;
+        if (preempted || cfq_cfqq_queue_new(cfqq)) {
+                struct list_head *n = list;
+                struct cfq_queue *__cfqq;
 
-                list_add_tail(&cfqq->cfq_list, list);
-                return;
-        }
+                while (n->next != list) {
+                        __cfqq = list_entry_cfqq(n->next);
+                        if (!cfq_cfqq_queue_new(__cfqq))
+                                break;
 
-        /*
-         * sort by when queue was last serviced
-         */
-        entry = list;
-        while ((entry = entry->prev) != list) {
-                struct cfq_queue *__cfqq = list_entry_cfqq(entry);
+                        n = n->next;
+                }
 
-                if (!__cfqq->service_last)
-                        break;
-                if (time_before(__cfqq->service_last, cfqq->service_last))
-                        break;
+                list = n;
         }
 
-        list_add(&cfqq->cfq_list, entry);
+        list_add_tail(&cfqq->cfq_list, list);
 }
 
 /*
@@ -531,7 +418,7 @@ cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq)
 {
         BUG_ON(!cfq_cfqq_on_rr(cfqq));
         cfq_clear_cfqq_on_rr(cfqq);
-        list_move(&cfqq->cfq_list, &cfqd->empty_list);
+        list_del_init(&cfqq->cfq_list);
 
         BUG_ON(!cfqd->busy_queues);
         cfqd->busy_queues--;
@@ -540,81 +427,43 @@ cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq)
 /*
  * rb tree support functions
  */
-static inline void cfq_del_crq_rb(struct cfq_rq *crq)
+static inline void cfq_del_rq_rb(struct request *rq)
 {
-        struct cfq_queue *cfqq = crq->cfq_queue;
+        struct cfq_queue *cfqq = RQ_CFQQ(rq);
         struct cfq_data *cfqd = cfqq->cfqd;
-        const int sync = cfq_crq_is_sync(crq);
+        const int sync = rq_is_sync(rq);
 
         BUG_ON(!cfqq->queued[sync]);
         cfqq->queued[sync]--;
 
-        cfq_update_next_crq(crq);
-
-        rb_erase(&crq->rb_node, &cfqq->sort_list);
+        elv_rb_del(&cfqq->sort_list, rq);
 
         if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list))
                 cfq_del_cfqq_rr(cfqd, cfqq);
 }
 
-static struct cfq_rq *
-__cfq_add_crq_rb(struct cfq_rq *crq)
+static void cfq_add_rq_rb(struct request *rq)
 {
-        struct rb_node **p = &crq->cfq_queue->sort_list.rb_node;
-        struct rb_node *parent = NULL;
-        struct cfq_rq *__crq;
-
-        while (*p) {
-                parent = *p;
-                __crq = rb_entry_crq(parent);
-
-                if (crq->rb_key < __crq->rb_key)
-                        p = &(*p)->rb_left;
-                else if (crq->rb_key > __crq->rb_key)
-                        p = &(*p)->rb_right;
-                else
-                        return __crq;
-        }
-
-        rb_link_node(&crq->rb_node, parent, p);
-        return NULL;
-}
-
-static void cfq_add_crq_rb(struct cfq_rq *crq)
-{
-        struct cfq_queue *cfqq = crq->cfq_queue;
+        struct cfq_queue *cfqq = RQ_CFQQ(rq);
         struct cfq_data *cfqd = cfqq->cfqd;
-        struct request *rq = crq->request;
-        struct cfq_rq *__alias;
+        struct request *__alias;
 
-        crq->rb_key = rq_rb_key(rq);
-        cfqq->queued[cfq_crq_is_sync(crq)]++;
+        cfqq->queued[rq_is_sync(rq)]++;
 
         /*
          * looks a little odd, but the first insert might return an alias.
          * if that happens, put the alias on the dispatch list
          */
-        while ((__alias = __cfq_add_crq_rb(crq)) != NULL)
+        while ((__alias = elv_rb_add(&cfqq->sort_list, rq)) != NULL)
                 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);
-
-        /*
-         * check if this request is a better next-serve candidate
-         */
-        cfqq->next_crq = cfq_choose_req(cfqd, cfqq->next_crq, crq);
 }
 
 static inline void
-cfq_reposition_crq_rb(struct cfq_queue *cfqq, struct cfq_rq *crq)
+cfq_reposition_rq_rb(struct cfq_queue *cfqq, struct request *rq)
 {
-        rb_erase(&crq->rb_node, &cfqq->sort_list);
-        cfqq->queued[cfq_crq_is_sync(crq)]--;
-
-        cfq_add_crq_rb(crq);
+        elv_rb_del(&cfqq->sort_list, rq);
+        cfqq->queued[rq_is_sync(rq)]--;
+        cfq_add_rq_rb(rq);
 }
 
 static struct request *
@@ -623,27 +472,14 @@ cfq_find_rq_fmerge(struct cfq_data *cfqd, struct bio *bio)
         struct task_struct *tsk = current;
         pid_t key = cfq_queue_pid(tsk, bio_data_dir(bio));
         struct cfq_queue *cfqq;
-        struct rb_node *n;
-        sector_t sector;
 
         cfqq = cfq_find_cfq_hash(cfqd, key, tsk->ioprio);
-        if (!cfqq)
-                goto out;
-
-        sector = bio->bi_sector + bio_sectors(bio);
-        n = cfqq->sort_list.rb_node;
-        while (n) {
-                struct cfq_rq *crq = rb_entry_crq(n);
+        if (cfqq) {
+                sector_t sector = bio->bi_sector + bio_sectors(bio);
 
-                if (sector < crq->rb_key)
-                        n = n->rb_left;
-                else if (sector > crq->rb_key)
-                        n = n->rb_right;
-                else
-                        return crq->request;
+                return elv_rb_find(&cfqq->sort_list, sector);
         }
 
-out:
         return NULL;
 }
 
@@ -673,11 +509,18 @@ static void cfq_deactivate_request(request_queue_t *q, struct request *rq)
 
 static void cfq_remove_request(struct request *rq)
 {
-        struct cfq_rq *crq = RQ_DATA(rq);
+        struct cfq_queue *cfqq = RQ_CFQQ(rq);
+
+        if (cfqq->next_rq == rq)
+                cfqq->next_rq = cfq_find_next_rq(cfqq->cfqd, cfqq, rq);
 
         list_del_init(&rq->queuelist);
-        cfq_del_crq_rb(crq);
-        cfq_del_crq_hash(crq);
+        cfq_del_rq_rb(rq);
+
+        if (rq_is_meta(rq)) {
+                WARN_ON(!cfqq->meta_pending);
+                cfqq->meta_pending--;
+        }
 }
 
 static int
@@ -685,39 +528,23 @@ cfq_merge(request_queue_t *q, struct request **req, struct bio *bio)
 {
         struct cfq_data *cfqd = q->elevator->elevator_data;
         struct request *__rq;
-        int ret;
-
-        __rq = cfq_find_rq_hash(cfqd, bio->bi_sector);
-        if (__rq && elv_rq_merge_ok(__rq, bio)) {
-                ret = ELEVATOR_BACK_MERGE;
-                goto out;
-        }
 
         __rq = cfq_find_rq_fmerge(cfqd, bio);
         if (__rq && elv_rq_merge_ok(__rq, bio)) {
-                ret = ELEVATOR_FRONT_MERGE;
-                goto out;
+                *req = __rq;
+                return ELEVATOR_FRONT_MERGE;
         }
 
         return ELEVATOR_NO_MERGE;
-out:
-        *req = __rq;
-        return ret;
 }
 
-static void cfq_merged_request(request_queue_t *q, struct request *req)
+static void cfq_merged_request(request_queue_t *q, struct request *req,
+                               int type)
 {
-        struct cfq_data *cfqd = q->elevator->elevator_data;
-        struct cfq_rq *crq = RQ_DATA(req);
-
-        cfq_del_crq_hash(crq);
-        cfq_add_crq_hash(cfqd, crq);
-
-        if (rq_rb_key(req) != crq->rb_key) {
-                struct cfq_queue *cfqq = crq->cfq_queue;
+        if (type == ELEVATOR_FRONT_MERGE) {
+                struct cfq_queue *cfqq = RQ_CFQQ(req);
 
-                cfq_update_next_crq(crq);
-                cfq_reposition_crq_rb(cfqq, crq);
+                cfq_reposition_rq_rb(cfqq, req);
         }
 }
 
@@ -725,8 +552,6 @@ static void
 cfq_merged_requests(request_queue_t *q, struct request *rq,
                     struct request *next)
 {
-        cfq_merged_request(q, rq);
-
         /*
          * reposition in fifo if next is older than rq
          */
@@ -768,13 +593,12 @@ __cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq,
         if (cfq_cfqq_wait_request(cfqq))
                 del_timer(&cfqd->idle_slice_timer);
 
-        if (!preempted && !cfq_cfqq_dispatched(cfqq)) {
-                cfqq->service_last = now;
+        if (!preempted && !cfq_cfqq_dispatched(cfqq))
                 cfq_schedule_dispatch(cfqd);
-        }
 
         cfq_clear_cfqq_must_dispatch(cfqq);
         cfq_clear_cfqq_wait_request(cfqq);
+        cfq_clear_cfqq_queue_new(cfqq);
 
         /*
          * store what was left of this slice, if the queue idled out
@@ -868,26 +692,25 @@ static struct cfq_queue *cfq_set_active_queue(struct cfq_data *cfqd)
 {
         struct cfq_queue *cfqq = NULL;
 
-        /*
-         * if current list is non-empty, grab first entry. if it is empty,
-         * get next prio level and grab first entry then if any are spliced
-         */
-        if (!list_empty(&cfqd->cur_rr) || cfq_get_next_prio_level(cfqd) != -1)
+        if (!list_empty(&cfqd->cur_rr) || cfq_get_next_prio_level(cfqd) != -1) {
+                /*
+                 * if current list is non-empty, grab first entry. if it is
+                 * empty, get next prio level and grab first entry then if any
+                 * are spliced
+                 */
                 cfqq = list_entry_cfqq(cfqd->cur_rr.next);
-
-        /*
-         * If no new queues are available, check if the busy list has some
-         * before falling back to idle io.
-         */
-        if (!cfqq && !list_empty(&cfqd->busy_rr))
+        } else if (!list_empty(&cfqd->busy_rr)) {
+                /*
+                 * If no new queues are available, check if the busy list has
+                 * some before falling back to idle io.
+                 */
                 cfqq = list_entry_cfqq(cfqd->busy_rr.next);
-
-        /*
-         * if we have idle queues and no rt or be queues had pending
-         * requests, either allow immediate service if the grace period
-         * has passed or arm the idle grace timer
-         */
-        if (!cfqq && !list_empty(&cfqd->idle_rr)) {
+        } else if (!list_empty(&cfqd->idle_rr)) {
+                /*
+                 * if we have idle queues and no rt or be queues had pending
+                 * requests, either allow immediate service if the grace period
+                 * has passed or arm the idle grace timer
+                 */
                 unsigned long end = cfqd->last_end_request + CFQ_IDLE_GRACE;
 
                 if (time_after_eq(jiffies, end))
@@ -942,16 +765,14 @@ static int cfq_arm_slice_timer(struct cfq_data *cfqd, struct cfq_queue *cfqq)
         return 1;
 }
 
-static void cfq_dispatch_insert(request_queue_t *q, struct cfq_rq *crq)
+static void cfq_dispatch_insert(request_queue_t *q, struct request *rq)
 {
         struct cfq_data *cfqd = q->elevator->elevator_data;
-        struct cfq_queue *cfqq = crq->cfq_queue;
-        struct request *rq;
+        struct cfq_queue *cfqq = RQ_CFQQ(rq);
 
-        cfqq->next_crq = cfq_find_next_crq(cfqd, cfqq, crq);
-        cfq_remove_request(crq->request);
-        cfqq->on_dispatch[cfq_crq_is_sync(crq)]++;
-        elv_dispatch_sort(q, crq->request);
+        cfq_remove_request(rq);
+        cfqq->on_dispatch[rq_is_sync(rq)]++;
+        elv_dispatch_sort(q, rq);
 
         rq = list_entry(q->queue_head.prev, struct request, queuelist);
         cfqd->last_sector = rq->sector + rq->nr_sectors;
@@ -960,24 +781,23 @@ static void cfq_dispatch_insert(request_queue_t *q, struct cfq_rq *crq)
 /*
  * return expired entry, or NULL to just start from scratch in rbtree
  */
-static inline struct cfq_rq *cfq_check_fifo(struct cfq_queue *cfqq)
+static inline struct request *cfq_check_fifo(struct cfq_queue *cfqq)
 {
         struct cfq_data *cfqd = cfqq->cfqd;
         struct request *rq;
-        struct cfq_rq *crq;
+        int fifo;
 
         if (cfq_cfqq_fifo_expire(cfqq))
                 return NULL;
+        if (list_empty(&cfqq->fifo))
+                return NULL;
 
-        if (!list_empty(&cfqq->fifo)) {
-                int fifo = cfq_cfqq_class_sync(cfqq);
+        fifo = cfq_cfqq_class_sync(cfqq);
+        rq = rq_entry_fifo(cfqq->fifo.next);
 
-                crq = RQ_DATA(list_entry_fifo(cfqq->fifo.next));
-                rq = crq->request;
-                if (time_after(jiffies, rq->start_time + cfqd->cfq_fifo_expire[fifo])) {
-                        cfq_mark_cfqq_fifo_expire(cfqq);
-                        return crq;
-                }
+        if (time_after(jiffies, rq->start_time + cfqd->cfq_fifo_expire[fifo])) {
+                cfq_mark_cfqq_fifo_expire(cfqq);
+                return rq;
         }
 
         return NULL;
@@ -1063,25 +883,25 @@ __cfq_dispatch_requests(struct cfq_data *cfqd, struct cfq_queue *cfqq,
         BUG_ON(RB_EMPTY_ROOT(&cfqq->sort_list));
 
         do {
-                struct cfq_rq *crq;
+                struct request *rq;
 
                 /*
                  * follow expired path, else get first next available
                  */
-                if ((crq = cfq_check_fifo(cfqq)) == NULL)
-                        crq = cfqq->next_crq;
+                if ((rq = cfq_check_fifo(cfqq)) == NULL)
+                        rq = cfqq->next_rq;
 
                 /*
                  * finally, insert request into driver dispatch list
                  */
-                cfq_dispatch_insert(cfqd->queue, crq);
+                cfq_dispatch_insert(cfqd->queue, rq);
 
                 cfqd->dispatch_slice++;
                 dispatched++;
 
                 if (!cfqd->active_cic) {
-                        atomic_inc(&crq->io_context->ioc->refcount);
-                        cfqd->active_cic = crq->io_context;
+                        atomic_inc(&RQ_CIC(rq)->ioc->refcount);
+                        cfqd->active_cic = RQ_CIC(rq);
                 }
 
                 if (RB_EMPTY_ROOT(&cfqq->sort_list))
@@ -1112,13 +932,12 @@ static int
 cfq_forced_dispatch_cfqqs(struct list_head *list)
 {
         struct cfq_queue *cfqq, *next;
-        struct cfq_rq *crq;
         int dispatched;
 
         dispatched = 0;
         list_for_each_entry_safe(cfqq, next, list, cfq_list) {
-                while ((crq = cfqq->next_crq)) {
-                        cfq_dispatch_insert(cfqq->cfqd->queue, crq);
+                while (cfqq->next_rq) {
+                        cfq_dispatch_insert(cfqq->cfqd->queue, cfqq->next_rq);
                         dispatched++;
                 }
                 BUG_ON(!list_empty(&cfqq->fifo));
@@ -1194,8 +1013,8 @@ cfq_dispatch_requests(request_queue_t *q, int force)
 }
 
 /*
- * 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.
+ * task holds one reference to the queue, dropped when task exits. each rq
+ * in-flight on this queue also holds a reference, dropped when rq is freed.
  *
  * queue lock must be held here.
  */
@@ -1223,7 +1042,7 @@ static void cfq_put_queue(struct cfq_queue *cfqq)
         kmem_cache_free(cfq_pool, cfqq);
 }
 
-static inline struct cfq_queue *
+static struct cfq_queue *
 __cfq_find_cfq_hash(struct cfq_data *cfqd, unsigned int key, unsigned int prio,
                     const int hashval)
 {
@@ -1260,62 +1079,63 @@ static void cfq_free_io_context(struct io_context *ioc)
                 freed++;
         }
 
-        if (atomic_sub_and_test(freed, &ioc_count) && ioc_gone)
+        elv_ioc_count_mod(ioc_count, -freed);
+
+        if (ioc_gone && !elv_ioc_count_read(ioc_count))
                 complete(ioc_gone);
 }
 
-static void cfq_trim(struct io_context *ioc)
+static void cfq_exit_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq)
 {
-        ioc->set_ioprio = NULL;
-        cfq_free_io_context(ioc);
+        if (unlikely(cfqq == cfqd->active_queue))
+                __cfq_slice_expired(cfqd, cfqq, 0);
+
+        cfq_put_queue(cfqq);
 }
 
-/*
- * Called with interrupts disabled
- */
-static void cfq_exit_single_io_context(struct cfq_io_context *cic)
+static void __cfq_exit_single_io_context(struct cfq_data *cfqd,
+                                         struct cfq_io_context *cic)
 {
-        struct cfq_data *cfqd = cic->key;
-        request_queue_t *q;
-
-        if (!cfqd)
-                return;
-
-        q = cfqd->queue;
-
-        WARN_ON(!irqs_disabled());
-
-        spin_lock(q->queue_lock);
+        list_del_init(&cic->queue_list);
+        smp_wmb();
+        cic->key = NULL;
 
         if (cic->cfqq[ASYNC]) {
-                if (unlikely(cic->cfqq[ASYNC] == cfqd->active_queue))
-                        __cfq_slice_expired(cfqd, cic->cfqq[ASYNC], 0);
-                cfq_put_queue(cic->cfqq[ASYNC]);
+                cfq_exit_cfqq(cfqd, cic->cfqq[ASYNC]);
                 cic->cfqq[ASYNC] = NULL;
         }
 
         if (cic->cfqq[SYNC]) {
-                if (unlikely(cic->cfqq[SYNC] == cfqd->active_queue))
-                        __cfq_slice_expired(cfqd, cic->cfqq[SYNC], 0);
-                cfq_put_queue(cic->cfqq[SYNC]);
+                cfq_exit_cfqq(cfqd, cic->cfqq[SYNC]);
                 cic->cfqq[SYNC] = NULL;
         }
+}
 
-        cic->key = NULL;
-        list_del_init(&cic->queue_list);
-        spin_unlock(q->queue_lock);
+
+/*
+ * Called with interrupts disabled
+ */
+static void cfq_exit_single_io_context(struct cfq_io_context *cic)
+{
+        struct cfq_data *cfqd = cic->key;
+
+        if (cfqd) {
+                request_queue_t *q = cfqd->queue;
+
+                spin_lock_irq(q->queue_lock);
+                __cfq_exit_single_io_context(cfqd, cic);
+                spin_unlock_irq(q->queue_lock);
+        }
 }
 
 static void cfq_exit_io_context(struct io_context *ioc)
 {
         struct cfq_io_context *__cic;
-        unsigned long flags;
         struct rb_node *n;
 
         /*
          * put the reference this task is holding to the various queues
          */
-        spin_lock_irqsave(&cfq_exit_lock, flags);
 
         n = rb_first(&ioc->cic_root);
         while (n != NULL) {
@@ -1324,22 +1144,21 @@ static void cfq_exit_io_context(struct io_context *ioc)
                 cfq_exit_single_io_context(__cic);
                 n = rb_next(n);
         }
-
-        spin_unlock_irqrestore(&cfq_exit_lock, flags);
 }
 
 static struct cfq_io_context *
 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);
+        struct cfq_io_context *cic;
 
+        cic = kmem_cache_alloc_node(cfq_ioc_pool, gfp_mask, cfqd->queue->node);
         if (cic) {
                 memset(cic, 0, sizeof(*cic));
                 cic->last_end_request = jiffies;
                 INIT_LIST_HEAD(&cic->queue_list);
                 cic->dtor = cfq_free_io_context;
                 cic->exit = cfq_exit_io_context;
-                atomic_inc(&ioc_count);
+                elv_ioc_count_inc(ioc_count);
         }
 
         return cic;
@@ -1420,15 +1239,12 @@ static inline void changed_ioprio(struct cfq_io_context *cic)
         spin_unlock(cfqd->queue->queue_lock);
 }
 
-/*
- * callback from sys_ioprio_set, irqs are disabled
- */
-static int cfq_ioc_set_ioprio(struct io_context *ioc, unsigned int ioprio)
+static void cfq_ioc_set_ioprio(struct io_context *ioc)
 {
         struct cfq_io_context *cic;
         struct rb_node *n;
 
-        spin_lock(&cfq_exit_lock);
+        ioc->ioprio_changed = 0;
 
         n = rb_first(&ioc->cic_root);
         while (n != NULL) {
@@ -1437,10 +1253,6 @@ static int cfq_ioc_set_ioprio(struct io_context *ioc, unsigned int ioprio)
                 changed_ioprio(cic);
                 n = rb_next(n);
         }
-
-        spin_unlock(&cfq_exit_lock);
-
-        return 0;
 }
 
 static struct cfq_queue *
@@ -1460,12 +1272,18 @@ retry:
                         cfqq = new_cfqq;
                         new_cfqq = NULL;
                 } else if (gfp_mask & __GFP_WAIT) {
+                        /*
+                         * Inform the allocator of the fact that we will
+                         * just repeat this allocation if it fails, to allow
+                         * the allocator to do whatever it needs to attempt to
+                         * free memory.
+                         */
                         spin_unlock_irq(cfqd->queue->queue_lock);
-                        new_cfqq = kmem_cache_alloc(cfq_pool, gfp_mask);
+                        new_cfqq = kmem_cache_alloc_node(cfq_pool, gfp_mask|__GFP_NOFAIL, cfqd->queue->node);
                         spin_lock_irq(cfqd->queue->queue_lock);
                         goto retry;
                 } else {
-                        cfqq = kmem_cache_alloc(cfq_pool, gfp_mask);
+                        cfqq = kmem_cache_alloc_node(cfq_pool, gfp_mask, cfqd->queue->node);
                         if (!cfqq)
                                 goto out;
                 }
@@ -1480,13 +1298,13 @@ retry:
                 hlist_add_head(&cfqq->cfq_hash, &cfqd->cfq_hash[hashval]);
                 atomic_set(&cfqq->ref, 0);
                 cfqq->cfqd = cfqd;
-                cfqq->service_last = 0;
                 /*
                  * set ->slice_left to allow preemption for a new process
                  */
                 cfqq->slice_left = 2 * cfqd->cfq_slice_idle;
                 cfq_mark_cfqq_idle_window(cfqq);
                 cfq_mark_cfqq_prio_changed(cfqq);
+                cfq_mark_cfqq_queue_new(cfqq);
                 cfq_init_prio_data(cfqq);
         }
 
@@ -1502,12 +1320,10 @@ out:
 static void
 cfq_drop_dead_cic(struct io_context *ioc, struct cfq_io_context *cic)
 {
-        spin_lock(&cfq_exit_lock);
+        WARN_ON(!list_empty(&cic->queue_list));
         rb_erase(&cic->rb_node, &ioc->cic_root);
-        list_del_init(&cic->queue_list);
-        spin_unlock(&cfq_exit_lock);
         kmem_cache_free(cfq_ioc_pool, cic);
-        atomic_dec(&ioc_count);
+        elv_ioc_count_dec(ioc_count);
 }
 
 static struct cfq_io_context *
@@ -1551,7 +1367,6 @@ cfq_cic_link(struct cfq_data *cfqd, struct io_context *ioc,
         cic->ioc = ioc;
         cic->key = cfqd;
 
-        ioc->set_ioprio = cfq_ioc_set_ioprio;
 restart:
         parent = NULL;
         p = &ioc->cic_root.rb_node;
@@ -1573,11 +1388,12 @@ restart:
                         BUG();
         }
 
-        spin_lock(&cfq_exit_lock);
         rb_link_node(&cic->rb_node, parent, p);
         rb_insert_color(&cic->rb_node, &ioc->cic_root);
+
+        spin_lock_irq(cfqd->queue->queue_lock);
         list_add(&cic->queue_list, &cfqd->cic_list);
-        spin_unlock(&cfq_exit_lock);
+        spin_unlock_irq(cfqd->queue->queue_lock);
 }
 
 /*
@@ -1593,7 +1409,7 @@ cfq_get_io_context(struct cfq_data *cfqd, gfp_t gfp_mask)
 
         might_sleep_if(gfp_mask & __GFP_WAIT);
 
-        ioc = get_io_context(gfp_mask);
+        ioc = get_io_context(gfp_mask, cfqd->queue->node);
         if (!ioc)
                 return NULL;
 
@@ -1607,6 +1423,10 @@ cfq_get_io_context(struct cfq_data *cfqd, gfp_t gfp_mask)
 
         cfq_cic_link(cfqd, ioc, cic);
 out:
+        smp_read_barrier_depends();
+        if (unlikely(ioc->ioprio_changed))
+                cfq_ioc_set_ioprio(ioc);
+
         return cic;
 err:
         put_io_context(ioc);
@@ -1640,15 +1460,15 @@ cfq_update_io_thinktime(struct cfq_data *cfqd, struct cfq_io_context *cic)
 
 static void
 cfq_update_io_seektime(struct cfq_data *cfqd, struct cfq_io_context *cic,
-                       struct cfq_rq *crq)
+                       struct request *rq)
 {
         sector_t sdist;
         u64 total;
 
-        if (cic->last_request_pos < crq->request->sector)
-                sdist = crq->request->sector - cic->last_request_pos;
+        if (cic->last_request_pos < rq->sector)
+                sdist = rq->sector - cic->last_request_pos;
         else
-                sdist = cic->last_request_pos - crq->request->sector;
+                sdist = cic->last_request_pos - rq->sector;
 
         /*
          * Don't allow the seek distance to get too large from the
@@ -1699,7 +1519,7 @@ cfq_update_idle_window(struct cfq_data *cfqd, struct cfq_queue *cfqq,
  */
 static int
 cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq,
-                   struct cfq_rq *crq)
+                   struct request *rq)
 {
         struct cfq_queue *cfqq = cfqd->active_queue;
 
@@ -1718,7 +1538,17 @@ cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq,
          */
         if (new_cfqq->slice_left < cfqd->cfq_slice_idle)
                 return 0;
-        if (cfq_crq_is_sync(crq) && !cfq_cfqq_sync(cfqq))
+        /*
+         * if the new request is sync, but the currently running queue is
+         * not, let the sync request have priority.
+         */
+        if (rq_is_sync(rq) && !cfq_cfqq_sync(cfqq))
+                return 1;
+        /*
+         * So both queues are sync. Let the new request get disk time if
+         * it's a metadata request and the current queue is doing regular IO.
+         */
+        if (rq_is_meta(rq) && !cfqq->meta_pending)
                 return 1;
 
         return 0;
@@ -1730,47 +1560,45 @@ cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq,
  */
 static void cfq_preempt_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq)
 {
-        struct cfq_queue *__cfqq, *next;
-
-        list_for_each_entry_safe(__cfqq, next, &cfqd->cur_rr, cfq_list)
-                cfq_resort_rr_list(__cfqq, 1);
+        cfq_slice_expired(cfqd, 1);
 
         if (!cfqq->slice_left)
                 cfqq->slice_left = cfq_prio_to_slice(cfqd, cfqq) / 2;
 
-        cfqq->slice_end = cfqq->slice_left + jiffies;
-        cfq_slice_expired(cfqd, 1);
-        __cfq_set_active_queue(cfqd, cfqq);
-}
-
-/*
- * should really be a ll_rw_blk.c helper
- */
-static void cfq_start_queueing(struct cfq_data *cfqd, struct cfq_queue *cfqq)
-{
-        request_queue_t *q = cfqd->queue;
+        /*
+         * Put the new queue at the front of the of the current list,
+         * so we know that it will be selected next.
+         */
+        BUG_ON(!cfq_cfqq_on_rr(cfqq));
+        list_move(&cfqq->cfq_list, &cfqd->cur_rr);
 
-        if (!blk_queue_plugged(q))
-                q->request_fn(q);
-        else
-                __generic_unplug_device(q);
+        cfqq->slice_end = cfqq->slice_left + jiffies;
 }
 
 /*
- * Called when a new fs request (crq) is added (to cfqq). Check if there's
+ * Called when a new fs request (rq) is added (to cfqq). Check if there's
  * something we should do about it
  */
 static void
-cfq_crq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq,
-                 struct cfq_rq *crq)
+cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq,
+                struct request *rq)
 {
-        struct cfq_io_context *cic = crq->io_context;
+        struct cfq_io_context *cic = RQ_CIC(rq);
+
+        if (rq_is_meta(rq))
+                cfqq->meta_pending++;
+
+        /*
+         * check if this request is a better next-serve candidate)) {
+         */
+        cfqq->next_rq = cfq_choose_req(cfqd, cfqq->next_rq, rq);
+        BUG_ON(!cfqq->next_rq);
 
         /*
          * we never wait for an async request and we don't allow preemption
          * of an async request. so just return early
          */
-        if (!cfq_crq_is_sync(crq)) {
+        if (!rq_is_sync(rq)) {
                 /*
                  * sync process issued an async request, if it's waiting
                  * then expire it and kick rq handling.
@@ -1778,17 +1606,17 @@ cfq_crq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq,
                 if (cic == cfqd->active_cic &&
                     del_timer(&cfqd->idle_slice_timer)) {
                         cfq_slice_expired(cfqd, 0);
-                        cfq_start_queueing(cfqd, cfqq);
+                        blk_start_queueing(cfqd->queue);
                 }
                 return;
         }
 
         cfq_update_io_thinktime(cfqd, cic);
-        cfq_update_io_seektime(cfqd, cic, crq);
+        cfq_update_io_seektime(cfqd, cic, rq);
         cfq_update_idle_window(cfqd, cfqq, cic);
 
         cic->last_queue = jiffies;
-        cic->last_request_pos = crq->request->sector + crq->request->nr_sectors;
+        cic->last_request_pos = rq->sector + rq->nr_sectors;
 
         if (cfqq == cfqd->active_queue) {
                 /*
@@ -1799,9 +1627,9 @@ cfq_crq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq,
                 if (cfq_cfqq_wait_request(cfqq)) {
                         cfq_mark_cfqq_must_dispatch(cfqq);
                         del_timer(&cfqd->idle_slice_timer);
-                        cfq_start_queueing(cfqd, cfqq);
+                        blk_start_queueing(cfqd->queue);
                 }
-        } else if (cfq_should_preempt(cfqd, cfqq, crq)) {
+        } else if (cfq_should_preempt(cfqd, cfqq, rq)) {
                 /*
                  * not the active queue - expire current slice if it is
                  * idle and has expired it's mean thinktime or this new queue
@@ -1809,34 +1637,32 @@ cfq_crq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq,
                  */
                 cfq_preempt_queue(cfqd, cfqq);
                 cfq_mark_cfqq_must_dispatch(cfqq);
-                cfq_start_queueing(cfqd, cfqq);
+                blk_start_queueing(cfqd->queue);
         }
 }
 
 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;
+        struct cfq_queue *cfqq = RQ_CFQQ(rq);
 
         cfq_init_prio_data(cfqq);
 
-        cfq_add_crq_rb(crq);
+        cfq_add_rq_rb(rq);
 
-        list_add_tail(&rq->queuelist, &cfqq->fifo);
+        if (!cfq_cfqq_on_rr(cfqq))
+                cfq_add_cfqq_rr(cfqd, cfqq);
 
-        if (rq_mergeable(rq))
-                cfq_add_crq_hash(cfqd, crq);
+        list_add_tail(&rq->queuelist, &cfqq->fifo);
 
-        cfq_crq_enqueued(cfqd, cfqq, crq);
+        cfq_rq_enqueued(cfqd, cfqq, rq);
 }
 
 static void cfq_completed_request(request_queue_t *q, struct request *rq)
 {
-        struct cfq_rq *crq = RQ_DATA(rq);
-        struct cfq_queue *cfqq = crq->cfq_queue;
+        struct cfq_queue *cfqq = RQ_CFQQ(rq);
         struct cfq_data *cfqd = cfqq->cfqd;
-        const int sync = cfq_crq_is_sync(crq);
+        const int sync = rq_is_sync(rq);
         unsigned long now;
 
         now = jiffies;
@@ -1849,15 +1675,11 @@ static void cfq_completed_request(request_queue_t *q, struct request *rq)
         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_dispatched(cfqq) && cfq_cfqq_on_rr(cfqq))
+                cfq_resort_rr_list(cfqq, 0);
 
         if (sync)
-                crq->io_context->last_end_request = now;
+                RQ_CIC(rq)->last_end_request = now;
 
         /*
          * If this is the active queue, check if it needs to be expired,
@@ -1873,30 +1695,6 @@ static void cfq_completed_request(request_queue_t *q, struct request *rq)
         }
 }
 
-static struct request *
-cfq_former_request(request_queue_t *q, struct request *rq)
-{
-        struct cfq_rq *crq = RQ_DATA(rq);
-        struct rb_node *rbprev = rb_prev(&crq->rb_node);
-
-        if (rbprev)
-                return rb_entry_crq(rbprev)->request;
-
-        return NULL;
-}
-
-static struct request *
-cfq_latter_request(request_queue_t *q, struct request *rq)
-{
-        struct cfq_rq *crq = RQ_DATA(rq);
-        struct rb_node *rbnext = rb_next(&crq->rb_node);
-
-        if (rbnext)
-                return rb_entry_crq(rbnext)->request;
-
-        return NULL;
-}
-
 /*
  * we temporarily boost lower priority queues if they are holding fs exclusive
  * resources. they are boosted to normal prio (CLASS_BE/4)
@@ -1933,9 +1731,7 @@ static void cfq_prio_boost(struct cfq_queue *cfqq)
                 cfq_resort_rr_list(cfqq, 0);
 }
 
-static inline int
-__cfq_may_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq,
-                struct task_struct *task, int rw)
+static inline int __cfq_may_queue(struct cfq_queue *cfqq)
 {
         if ((cfq_cfqq_wait_request(cfqq) || cfq_cfqq_must_alloc(cfqq)) &&
             !cfq_cfqq_must_alloc_slice(cfqq)) {
@@ -1946,7 +1742,7 @@ __cfq_may_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq,
         return ELV_MQUEUE_MAY;
 }
 
-static int cfq_may_queue(request_queue_t *q, int rw, struct bio *bio)
+static int cfq_may_queue(request_queue_t *q, int rw)
 {
         struct cfq_data *cfqd = q->elevator->elevator_data;
         struct task_struct *tsk = current;
@@ -1963,48 +1759,30 @@ static int cfq_may_queue(request_queue_t *q, int rw, struct bio *bio)
                 cfq_init_prio_data(cfqq);
                 cfq_prio_boost(cfqq);
 
-                return __cfq_may_queue(cfqd, cfqq, tsk, rw);
+                return __cfq_may_queue(cfqq);
         }
 
         return ELV_MQUEUE_MAY;
 }
 
-static void cfq_check_waiters(request_queue_t *q, struct cfq_queue *cfqq)
-{
-        struct cfq_data *cfqd = q->elevator->elevator_data;
-
-        if (unlikely(cfqd->rq_starved)) {
-                struct request_list *rl = &q->rq;
-
-                smp_mb();
-                if (waitqueue_active(&rl->wait[READ]))
-                        wake_up(&rl->wait[READ]);
-                if (waitqueue_active(&rl->wait[WRITE]))
-                        wake_up(&rl->wait[WRITE]);
-        }
-}
-
 /*
  * queue lock held here
  */
 static void cfq_put_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 = RQ_CFQQ(rq);
 
-        if (crq) {
-                struct cfq_queue *cfqq = crq->cfq_queue;
+        if (cfqq) {
                 const int rw = rq_data_dir(rq);
 
                 BUG_ON(!cfqq->allocated[rw]);
                 cfqq->allocated[rw]--;
 
-                put_io_context(crq->io_context->ioc);
+                put_io_context(RQ_CIC(rq)->ioc);
 
-                mempool_free(crq, cfqd->crq_pool);
                 rq->elevator_private = NULL;
+                rq->elevator_private2 = NULL;
 
-                cfq_check_waiters(q, cfqq);
                 cfq_put_queue(cfqq);
         }
 }
@@ -2013,8 +1791,7 @@ static void cfq_put_request(request_queue_t *q, struct request *rq)
  * Allocate cfq data structures associated with this request.
  */
 static int
-cfq_set_request(request_queue_t *q, struct request *rq, struct bio *bio,
-                gfp_t gfp_mask)
+cfq_set_request(request_queue_t *q, struct request *rq, gfp_t gfp_mask)
 {
         struct cfq_data *cfqd = q->elevator->elevator_data;
         struct task_struct *tsk = current;
@@ -2022,7 +1799,6 @@ cfq_set_request(request_queue_t *q, struct request *rq, struct bio *bio,
         const int rw = rq_data_dir(rq);
         pid_t key = cfq_queue_pid(tsk, rw);
         struct cfq_queue *cfqq;
-        struct cfq_rq *crq;
         unsigned long flags;
         int is_sync = key != CFQ_KEY_ASYNC;
 
@@ -2046,42 +1822,18 @@ cfq_set_request(request_queue_t *q, struct request *rq, struct bio *bio,
 
         cfqq->allocated[rw]++;
         cfq_clear_cfqq_must_alloc(cfqq);
-        cfqd->rq_starved = 0;
         atomic_inc(&cfqq->ref);
-        spin_unlock_irqrestore(q->queue_lock, flags);
 
-        crq = mempool_alloc(cfqd->crq_pool, gfp_mask);
-        if (crq) {
-                RB_CLEAR_NODE(&crq->rb_node);
-                crq->rb_key = 0;
-                crq->request = rq;
-                INIT_HLIST_NODE(&crq->hash);
-                crq->cfq_queue = cfqq;
-                crq->io_context = cic;
-
-                if (is_sync)
-                        cfq_mark_crq_is_sync(crq);
-                else
-                        cfq_clear_crq_is_sync(crq);
+        spin_unlock_irqrestore(q->queue_lock, flags);
 
-                rq->elevator_private = crq;
-                return 0;
-        }
+        rq->elevator_private = cic;
+        rq->elevator_private2 = cfqq;
+        return 0;
 
-        spin_lock_irqsave(q->queue_lock, flags);
-        cfqq->allocated[rw]--;
-        if (!(cfqq->allocated[0] + cfqq->allocated[1]))
-                cfq_mark_cfqq_must_alloc(cfqq);
-        cfq_put_queue(cfqq);
 queue_fail:
         if (cic)
                 put_io_context(cic->ioc);
-        /*
-         * mark us rq allocation starved. we need to kickstart the process
-         * ourselves if there are no pending requests that can do it for us.
-         * that would be an extremely rare OOM situation
-         */
-        cfqd->rq_starved = 1;
+
         cfq_schedule_dispatch(cfqd);
         spin_unlock_irqrestore(q->queue_lock, flags);
         return 1;
@@ -2090,27 +1842,10 @@ queue_fail:
 static void cfq_kick_queue(void *data)
 {
         request_queue_t *q = data;
-        struct cfq_data *cfqd = q->elevator->elevator_data;
         unsigned long flags;
 
         spin_lock_irqsave(q->queue_lock, flags);
-
-        if (cfqd->rq_starved) {
-                struct request_list *rl = &q->rq;
-
-                /*
-                 * we aren't guaranteed to get a request after this, but we
-                 * have to be opportunistic
-                 */
-                smp_mb();
-                if (waitqueue_active(&rl->wait[READ]))
-                        wake_up(&rl->wait[READ]);
-                if (waitqueue_active(&rl->wait[WRITE]))
-                        wake_up(&rl->wait[WRITE]);
-        }
-
-        blk_remove_plug(q);
-        q->request_fn(q);
+        blk_start_queueing(q);
         spin_unlock_irqrestore(q->queue_lock, flags);
 }
 
@@ -2193,7 +1928,6 @@ static void cfq_exit_queue(elevator_t *e)
 
         cfq_shutdown_timer_wq(cfqd);
 
-        spin_lock(&cfq_exit_lock);
         spin_lock_irq(q->queue_lock);
 
         if (cfqd->active_queue)
@@ -2203,25 +1937,14 @@ static void cfq_exit_queue(elevator_t *e)
                 struct cfq_io_context *cic = list_entry(cfqd->cic_list.next,
                                                         struct cfq_io_context,
                                                         queue_list);
-                if (cic->cfqq[ASYNC]) {
-                        cfq_put_queue(cic->cfqq[ASYNC]);
-                        cic->cfqq[ASYNC] = NULL;
-                }
-                if (cic->cfqq[SYNC]) {
-                        cfq_put_queue(cic->cfqq[SYNC]);
-                        cic->cfqq[SYNC] = NULL;
-                }
-                cic->key = NULL;
-                list_del_init(&cic->queue_list);
+
+                __cfq_exit_single_io_context(cfqd, cic);
         }
 
         spin_unlock_irq(q->queue_lock);
-        spin_unlock(&cfq_exit_lock);
 
         cfq_shutdown_timer_wq(cfqd);
 
-        mempool_destroy(cfqd->crq_pool);
-        kfree(cfqd->crq_hash);
         kfree(cfqd->cfq_hash);
         kfree(cfqd);
 }
@@ -2231,7 +1954,7 @@ static void *cfq_init_queue(request_queue_t *q, elevator_t *e)
         struct cfq_data *cfqd;
         int i;
 
-        cfqd = kmalloc(sizeof(*cfqd), GFP_KERNEL);
+        cfqd = kmalloc_node(sizeof(*cfqd), GFP_KERNEL, q->node);
         if (!cfqd)
                 return NULL;
 
@@ -2243,23 +1966,12 @@ static void *cfq_init_queue(request_queue_t *q, elevator_t *e)
         INIT_LIST_HEAD(&cfqd->busy_rr);
         INIT_LIST_HEAD(&cfqd->cur_rr);
         INIT_LIST_HEAD(&cfqd->idle_rr);
-        INIT_LIST_HEAD(&cfqd->empty_list);
         INIT_LIST_HEAD(&cfqd->cic_list);
 
-        cfqd->crq_hash = kmalloc(sizeof(struct hlist_head) * CFQ_MHASH_ENTRIES, GFP_KERNEL);
-        if (!cfqd->crq_hash)
-                goto out_crqhash;
-
-        cfqd->cfq_hash = kmalloc(sizeof(struct hlist_head) * CFQ_QHASH_ENTRIES, GFP_KERNEL);
+        cfqd->cfq_hash = kmalloc_node(sizeof(struct hlist_head) * CFQ_QHASH_ENTRIES, GFP_KERNEL, q->node);
         if (!cfqd->cfq_hash)
-                goto out_cfqhash;
-
-        cfqd->crq_pool = mempool_create_slab_pool(BLKDEV_MIN_RQ, crq_pool);
-        if (!cfqd->crq_pool)
-                goto out_crqpool;
+                goto out_free;
 
-        for (i = 0; i < CFQ_MHASH_ENTRIES; i++)
-                INIT_HLIST_HEAD(&cfqd->crq_hash[i]);
         for (i = 0; i < CFQ_QHASH_ENTRIES; i++)
                 INIT_HLIST_HEAD(&cfqd->cfq_hash[i]);
 
@@ -2275,7 +1987,6 @@ static void *cfq_init_queue(request_queue_t *q, elevator_t *e)
 
         INIT_WORK(&cfqd->unplug_work, cfq_kick_queue, q);
 
-        cfqd->cfq_queued = cfq_queued;
         cfqd->cfq_quantum = cfq_quantum;
         cfqd->cfq_fifo_expire[0] = cfq_fifo_expire[0];
         cfqd->cfq_fifo_expire[1] = cfq_fifo_expire[1];
@@ -2287,19 +1998,13 @@ static void *cfq_init_queue(request_queue_t *q, elevator_t *e)
         cfqd->cfq_slice_idle = cfq_slice_idle;
 
         return cfqd;
-out_crqpool:
-        kfree(cfqd->cfq_hash);
-out_cfqhash:
-        kfree(cfqd->crq_hash);
-out_crqhash:
+out_free:
         kfree(cfqd);
         return NULL;
 }
 
 static void cfq_slab_kill(void)
 {
-        if (crq_pool)
-                kmem_cache_destroy(crq_pool);
         if (cfq_pool)
                 kmem_cache_destroy(cfq_pool);
         if (cfq_ioc_pool)
@@ -2308,11 +2013,6 @@ static void cfq_slab_kill(void)
 
 static int __init cfq_slab_setup(void)
 {
-        crq_pool = kmem_cache_create("crq_pool", sizeof(struct cfq_rq), 0, 0,
-                                        NULL, NULL);
-        if (!crq_pool)
-                goto fail;
-
         cfq_pool = kmem_cache_create("cfq_pool", sizeof(struct cfq_queue), 0, 0,
                                         NULL, NULL);
         if (!cfq_pool)
@@ -2358,7 +2058,6 @@ static ssize_t __FUNC(elevator_t *e, char *page)			\
         return cfq_var_show(__data, (page));                            \
 }
 SHOW_FUNCTION(cfq_quantum_show, cfqd->cfq_quantum, 0);
-SHOW_FUNCTION(cfq_queued_show, cfqd->cfq_queued, 0);
 SHOW_FUNCTION(cfq_fifo_expire_sync_show, cfqd->cfq_fifo_expire[1], 1);
 SHOW_FUNCTION(cfq_fifo_expire_async_show, cfqd->cfq_fifo_expire[0], 1);
 SHOW_FUNCTION(cfq_back_seek_max_show, cfqd->cfq_back_max, 0);
@@ -2386,7 +2085,6 @@ static ssize_t __FUNC(elevator_t *e, const char *page, size_t count)	\
         return ret;                                                     \
 }
 STORE_FUNCTION(cfq_quantum_store, &cfqd->cfq_quantum, 1, UINT_MAX, 0);
-STORE_FUNCTION(cfq_queued_store, &cfqd->cfq_queued, 1, UINT_MAX, 0);
 STORE_FUNCTION(cfq_fifo_expire_sync_store, &cfqd->cfq_fifo_expire[1], 1, UINT_MAX, 1);
 STORE_FUNCTION(cfq_fifo_expire_async_store, &cfqd->cfq_fifo_expire[0], 1, UINT_MAX, 1);
 STORE_FUNCTION(cfq_back_seek_max_store, &cfqd->cfq_back_max, 0, UINT_MAX, 0);
@@ -2402,7 +2100,6 @@ STORE_FUNCTION(cfq_slice_async_rq_store, &cfqd->cfq_slice_async_rq, 1, UINT_MAX,
 
 static struct elv_fs_entry cfq_attrs[] = {
         CFQ_ATTR(quantum),
-        CFQ_ATTR(queued),
         CFQ_ATTR(fifo_expire_sync),
         CFQ_ATTR(fifo_expire_async),
         CFQ_ATTR(back_seek_max),
@@ -2425,14 +2122,14 @@ static struct elevator_type iosched_cfq = {
                 .elevator_deactivate_req_fn =   cfq_deactivate_request,
                 .elevator_queue_empty_fn =      cfq_queue_empty,
                 .elevator_completed_req_fn =    cfq_completed_request,
-                .elevator_former_req_fn =       cfq_former_request,
-                .elevator_latter_req_fn =       cfq_latter_request,
+                .elevator_former_req_fn =       elv_rb_former_request,
+                .elevator_latter_req_fn =       elv_rb_latter_request,
                 .elevator_set_req_fn =          cfq_set_request,
                 .elevator_put_req_fn =          cfq_put_request,
                 .elevator_may_queue_fn =        cfq_may_queue,
                 .elevator_init_fn =             cfq_init_queue,
                 .elevator_exit_fn =             cfq_exit_queue,
-                .trim =                         cfq_trim,
+                .trim =                         cfq_free_io_context,
         },
         .elevator_attrs =       cfq_attrs,
         .elevator_name =        "cfq",
@@ -2463,12 +2160,12 @@ static int __init cfq_init(void)
 
 static void __exit cfq_exit(void)
 {
-        DECLARE_COMPLETION(all_gone);
+        DECLARE_COMPLETION_ONSTACK(all_gone);
         elv_unregister(&iosched_cfq);
         ioc_gone = &all_gone;
         /* ioc_gone's update must be visible before reading ioc_count */
         smp_wmb();
-        if (atomic_read(&ioc_count))
+        if (elv_ioc_count_read(ioc_count))
                 wait_for_completion(ioc_gone);
         synchronize_rcu();
         cfq_slab_kill();