1 files changed, 55 insertions, 138 deletions

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);