16 files changed, 166 insertions, 120 deletions

diff --git a/block/blk-core.c b/block/blk-core.c
index 07ab75403e1a..2998fe3a2377 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -643,7 +643,7 @@ static inline void blk_free_request(struct request_queue *q, struct request *rq)
 }
 
 static struct request *
-blk_alloc_request(struct request_queue *q, int rw, int priv, gfp_t gfp_mask)
+blk_alloc_request(struct request_queue *q, int flags, int priv, gfp_t gfp_mask)
 {
         struct request *rq = mempool_alloc(q->rq.rq_pool, gfp_mask);
 
@@ -652,7 +652,7 @@ blk_alloc_request(struct request_queue *q, int rw, int priv, gfp_t gfp_mask)
 
         blk_rq_init(q, rq);
 
-        rq->cmd_flags = rw | REQ_ALLOCED;
+        rq->cmd_flags = flags | REQ_ALLOCED;
 
         if (priv) {
                 if (unlikely(elv_set_request(q, rq, gfp_mask))) {
@@ -792,6 +792,8 @@ static struct request *get_request(struct request_queue *q, int rw_flags,
         if (priv)
                 rl->elvpriv++;
 
+        if (blk_queue_io_stat(q))
+                rw_flags |= REQ_IO_STAT;
         spin_unlock_irq(q->queue_lock);
 
         rq = blk_alloc_request(q, rw_flags, priv, gfp_mask);
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 63760ca3da0f..23d2a6fe34a3 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -402,7 +402,10 @@ static int attempt_merge(struct request_queue *q, struct request *req,
 
         elv_merge_requests(q, req, next);
 
-        blk_account_io_merge(req);
+        /*
+         * 'next' is going away, so update stats accordingly
+         */
+        blk_account_io_merge(next);
 
         req->ioprio = ioprio_best(req->ioprio, next->ioprio);
         if (blk_rq_cpu_valid(next))
diff --git a/block/blk-settings.c b/block/blk-settings.c
index 69c42adde52b..57af728d94bb 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -156,26 +156,28 @@ EXPORT_SYMBOL(blk_queue_make_request);
 
 /**
  * blk_queue_bounce_limit - set bounce buffer limit for queue
- * @q:  the request queue for the device
- * @dma_addr:   bus address limit
+ * @q: the request queue for the device
+ * @dma_mask: the maximum address the device can handle
  *
  * Description:
  *    Different hardware can have different requirements as to what pages
  *    it can do I/O directly to. A low level driver can call
  *    blk_queue_bounce_limit to have lower memory pages allocated as bounce
- *    buffers for doing I/O to pages residing above @dma_addr.
+ *    buffers for doing I/O to pages residing above @dma_mask.
  **/
-void blk_queue_bounce_limit(struct request_queue *q, u64 dma_addr)
+void blk_queue_bounce_limit(struct request_queue *q, u64 dma_mask)
 {
-        unsigned long b_pfn = dma_addr >> PAGE_SHIFT;
+        unsigned long b_pfn = dma_mask >> PAGE_SHIFT;
         int dma = 0;
 
         q->bounce_gfp = GFP_NOIO;
 #if BITS_PER_LONG == 64
-        /* Assume anything <= 4GB can be handled by IOMMU.
-           Actually some IOMMUs can handle everything, but I don't
-           know of a way to test this here. */
-        if (b_pfn < (min_t(u64, 0x100000000UL, BLK_BOUNCE_HIGH) >> PAGE_SHIFT))
+        /*
+         * Assume anything <= 4GB can be handled by IOMMU.  Actually
+         * some IOMMUs can handle everything, but I don't know of a
+         * way to test this here.
+         */
+        if (b_pfn < (min_t(u64, 0xffffffffUL, BLK_BOUNCE_HIGH) >> PAGE_SHIFT))
                 dma = 1;
         q->bounce_pfn = max_low_pfn;
 #else
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index cac4e9febe6a..3ff9bba3379a 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -209,14 +209,10 @@ static ssize_t queue_iostats_store(struct request_queue *q, const char *page,
         ssize_t ret = queue_var_store(&stats, page, count);
 
         spin_lock_irq(q->queue_lock);
-        elv_quiesce_start(q);
-
         if (stats)
                 queue_flag_set(QUEUE_FLAG_IO_STAT, q);
         else
                 queue_flag_clear(QUEUE_FLAG_IO_STAT, q);
-
-        elv_quiesce_end(q);
         spin_unlock_irq(q->queue_lock);
 
         return ret;
diff --git a/block/blk-timeout.c b/block/blk-timeout.c
index bbbdc4b8ccf2..1ec0d503cacd 100644
--- a/block/blk-timeout.c
+++ b/block/blk-timeout.c
@@ -211,6 +211,12 @@ void blk_abort_queue(struct request_queue *q)
         struct request *rq, *tmp;
         LIST_HEAD(list);
 
+        /*
+         * Not a request based block device, nothing to abort
+         */
+        if (!q->request_fn)
+                return;
+
         spin_lock_irqsave(q->queue_lock, flags);
 
         elv_abort_queue(q);
@@ -224,6 +230,13 @@ void blk_abort_queue(struct request_queue *q)
         list_for_each_entry_safe(rq, tmp, &list, timeout_list)
                 blk_abort_request(rq);
 
+        /*
+         * Occasionally, blk_abort_request() will return without
+         * deleting the element from the list. Make sure we add those back
+         * instead of leaving them on the local stack list.
+         */
+        list_splice(&list, &q->timeout_list);
+
         spin_unlock_irqrestore(q->queue_lock, flags);
 
 }
diff --git a/block/blk.h b/block/blk.h
index 5dfc41267a08..79c85f7c9ff5 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -114,12 +114,7 @@ static inline int blk_cpu_to_group(int cpu)
 
 static inline int blk_do_io_stat(struct request *rq)
 {
-        struct gendisk *disk = rq->rq_disk;
-
-        if (!disk || !disk->queue)
-                return 0;
-
-        return blk_queue_io_stat(disk->queue) && (rq->cmd_flags & REQ_ELVPRIV);
+        return rq->rq_disk && blk_rq_io_stat(rq);
 }
 
 #endif
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 0d3b70de3d80..a55a9bd75bd1 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -154,6 +154,8 @@ struct cfq_queue {
         unsigned long rb_key;
         /* prio tree member */
         struct rb_node p_node;
+        /* prio tree root we belong to, if any */
+        struct rb_root *p_root;
         /* sorted list of pending requests */
         struct rb_root sort_list;
         /* if fifo isn't expired, next request to serve */