Merge branch 'for-linus' of git://git.kernel.dk/linux-block

* 'for-linus' of git://git.kernel.dk/linux-block:
  block: fix blk_queue_end_tag()
  block: re-use existing 'reading' variable instead of checking direction again
  block, cfq: fix empty queue crash caused by request merge

3 files changed, 15 insertions, 12 deletions

diff --git a/block/blk-map.c b/block/blk-map.c
index 164cd0059706..623e1cd4cffe 100644
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -311,7 +311,7 @@ int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf,
         if (IS_ERR(bio))
                 return PTR_ERR(bio);
 
-        if (rq_data_dir(rq) == WRITE)
+        if (!reading)
                 bio->bi_rw |= REQ_WRITE;
 
         if (do_copy)
diff --git a/block/blk-tag.c b/block/blk-tag.c
index e74d6d13838f..4af6f5cc1167 100644
--- a/block/blk-tag.c
+++ b/block/blk-tag.c
@@ -282,18 +282,9 @@ EXPORT_SYMBOL(blk_queue_resize_tags);
 void blk_queue_end_tag(struct request_queue *q, struct request *rq)
 {
         struct blk_queue_tag *bqt = q->queue_tags;
-        int tag = rq->tag;
+        unsigned tag = rq->tag; /* negative tags invalid */
 
-        BUG_ON(tag == -1);
-
-        if (unlikely(tag >= bqt->max_depth)) {
-                /*
-                 * This can happen after tag depth has been reduced.
-                 * But tag shouldn't be larger than real_max_depth.
-                 */
-                WARN_ON(tag >= bqt->real_max_depth);
-                return;
-        }
+        BUG_ON(tag >= bqt->real_max_depth);
 
         list_del_init(&rq->queuelist);
         rq->cmd_flags &= ~REQ_QUEUED;
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 4c12869fcf77..3548705b04e4 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -1655,6 +1655,8 @@ cfq_merged_requests(struct request_queue *q, struct request *rq,
                     struct request *next)
 {
         struct cfq_queue *cfqq = RQ_CFQQ(rq);
+        struct cfq_data *cfqd = q->elevator->elevator_data;
+
         /*
          * reposition in fifo if next is older than rq
          */
@@ -1669,6 +1671,16 @@ cfq_merged_requests(struct request_queue *q, struct request *rq,
         cfq_remove_request(next);
         cfq_blkiocg_update_io_merged_stats(&(RQ_CFQG(rq))->blkg,
                                         rq_data_dir(next), rq_is_sync(next));
+
+        cfqq = RQ_CFQQ(next);
+        /*
+         * all requests of this queue are merged to other queues, delete it
+         * from the service tree. If it's the active_queue,
+         * cfq_dispatch_requests() will choose to expire it or do idle
+         */
+        if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list) &&
+            cfqq != cfqd->active_queue)
+                cfq_del_cfqq_rr(cfqd, cfqq);
 }
 
 static int cfq_allow_merge(struct request_queue *q, struct request *rq,