5 files changed, 12 insertions, 13 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-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.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/include/linux/blkdev.h b/include/linux/blkdev.h
index ba54c834a590..2755d5c6da22 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -118,6 +118,7 @@ enum rq_flag_bits {
         __REQ_COPY_USER,        /* contains copies of user pages */
         __REQ_INTEGRITY,        /* integrity metadata has been remapped */
         __REQ_NOIDLE,           /* Don't anticipate more IO after this one */
+        __REQ_IO_STAT,          /* account I/O stat */
         __REQ_NR_BITS,          /* stops here */
 };
 
@@ -145,6 +146,7 @@ enum rq_flag_bits {
 #define REQ_COPY_USER   (1 << __REQ_COPY_USER)
 #define REQ_INTEGRITY   (1 << __REQ_INTEGRITY)
 #define REQ_NOIDLE      (1 << __REQ_NOIDLE)
+#define REQ_IO_STAT     (1 << __REQ_IO_STAT)
 
 #define BLK_MAX_CDB     16
 
@@ -598,6 +600,7 @@ enum {
                                  blk_failfast_transport(rq) ||  \
                                  blk_failfast_driver(rq))
 #define blk_rq_started(rq)      ((rq)->cmd_flags & REQ_STARTED)
+#define blk_rq_io_stat(rq)      ((rq)->cmd_flags & REQ_IO_STAT)
 
 #define blk_account_rq(rq)      (blk_rq_started(rq) && (blk_fs_request(rq) || blk_discard_rq(rq)))