1 files changed, 20 insertions, 16 deletions

diff --git a/block/blk-core.c b/block/blk-core.c
index 97e9e5405b83..79e41a76d96a 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -346,9 +346,10 @@ void blk_put_queue(struct request_queue *q)
 EXPORT_SYMBOL(blk_put_queue);
 
 /*
- * Note: If a driver supplied the queue lock, it should not zap that lock
- * unexpectedly as some queue cleanup components like elevator_exit() and
- * blk_throtl_exit() need queue lock.
+ * Note: If a driver supplied the queue lock, it is disconnected
+ * by this function. The actual state of the lock doesn't matter
+ * here as the request_queue isn't accessible after this point
+ * (QUEUE_FLAG_DEAD is set) and no other requests will be queued.
  */
 void blk_cleanup_queue(struct request_queue *q)
 {
@@ -365,10 +366,8 @@ void blk_cleanup_queue(struct request_queue *q)
         queue_flag_set_unlocked(QUEUE_FLAG_DEAD, q);
         mutex_unlock(&q->sysfs_lock);
 
-        if (q->elevator)
-                elevator_exit(q->elevator);
-
-        blk_throtl_exit(q);
+        if (q->queue_lock != &q->__queue_lock)
+                q->queue_lock = &q->__queue_lock;
 
         blk_put_queue(q);
 }
@@ -1165,7 +1164,7 @@ static bool bio_attempt_front_merge(struct request_queue *q,
  * true if merge was successful, otherwise false.
  */
 static bool attempt_plug_merge(struct task_struct *tsk, struct request_queue *q,
-                               struct bio *bio)
+                               struct bio *bio, unsigned int *request_count)
 {
         struct blk_plug *plug;
         struct request *rq;
@@ -1174,10 +1173,13 @@ static bool attempt_plug_merge(struct task_struct *tsk, struct request_queue *q,
         plug = tsk->plug;
         if (!plug)
                 goto out;
+        *request_count = 0;
 
         list_for_each_entry_reverse(rq, &plug->list, queuelist) {
                 int el_ret;
 
+                (*request_count)++;
+
                 if (rq->q != q)
                         continue;
 
@@ -1217,6 +1219,7 @@ void blk_queue_bio(struct request_queue *q, struct bio *bio)
         struct blk_plug *plug;
         int el_ret, rw_flags, where = ELEVATOR_INSERT_SORT;
         struct request *req;
+        unsigned int request_count = 0;
 
         /*
          * low level driver can indicate that it wants pages above a
@@ -1235,7 +1238,7 @@ void blk_queue_bio(struct request_queue *q, struct bio *bio)
          * Check if we can merge with the plugged list before grabbing
          * any locks.
          */
-        if (attempt_plug_merge(current, q, bio))
+        if (attempt_plug_merge(current, q, bio, &request_count))
                 return;
 
         spin_lock_irq(q->queue_lock);
@@ -1300,11 +1303,10 @@ get_rq:
                         if (__rq->q != q)
                                 plug->should_sort = 1;
                 }
+                if (request_count >= BLK_MAX_REQUEST_COUNT)
+                        blk_flush_plug_list(plug, false);
                 list_add_tail(&req->queuelist, &plug->list);
-                plug->count++;
                 drive_stat_acct(req, 1);
-                if (plug->count >= BLK_MAX_REQUEST_COUNT)
-                        blk_flush_plug_list(plug, false);
         } else {
                 spin_lock_irq(q->queue_lock);
                 add_acct_request(q, req, where);
@@ -1675,6 +1677,7 @@ EXPORT_SYMBOL_GPL(blk_rq_check_limits);
 int blk_insert_cloned_request(struct request_queue *q, struct request *rq)
 {
         unsigned long flags;
+        int where = ELEVATOR_INSERT_BACK;
 
         if (blk_rq_check_limits(q, rq))
                 return -EIO;
@@ -1691,7 +1694,10 @@ int blk_insert_cloned_request(struct request_queue *q, struct request *rq)
          */
         BUG_ON(blk_queued_rq(rq));
 
-        add_acct_request(q, rq, ELEVATOR_INSERT_BACK);
+        if (rq->cmd_flags & (REQ_FLUSH|REQ_FUA))
+                where = ELEVATOR_INSERT_FLUSH;
+
+        add_acct_request(q, rq, where);
         spin_unlock_irqrestore(q->queue_lock, flags);
 
         return 0;
@@ -2248,7 +2254,7 @@ static bool blk_end_bidi_request(struct request *rq, int error,
  *     %false - we are done with this request
  *     %true  - still buffers pending for this request
  **/
-static bool __blk_end_bidi_request(struct request *rq, int error,
+bool __blk_end_bidi_request(struct request *rq, int error,
                                    unsigned int nr_bytes, unsigned int bidi_bytes)
 {
         if (blk_update_bidi_request(rq, error, nr_bytes, bidi_bytes))
@@ -2617,7 +2623,6 @@ void blk_start_plug(struct blk_plug *plug)
         INIT_LIST_HEAD(&plug->list);
         INIT_LIST_HEAD(&plug->cb_list);
         plug->should_sort = 0;
-        plug->count = 0;
 
         /*
          * If this is a nested plug, don't actually assign it. It will be
@@ -2701,7 +2706,6 @@ void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule)
                 return;
 
         list_splice_init(&plug->list, &list);
-        plug->count = 0;
 
         if (plug->should_sort) {
                 list_sort(NULL, &list, plug_rq_cmp);