block: support > 16 byte CDBs for SG_IO

[deliverable/linux.git] / block / blk-mq.c

diff --git a/block/blk-mq.c b/block/blk-mq.c
index c9e89a8792e33f5eb723b95fcc9fa7e1a4b5888f..7950f8d7c1bb182b25aa9df8d41910941fc0022d 100644 (file)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -112,18 +112,22 @@ static void blk_mq_usage_counter_release(struct percpu_ref *ref)
  */
 void blk_mq_freeze_queue(struct request_queue *q)
 {
+       bool freeze;
+
        spin_lock_irq(q->queue_lock);
-       q->mq_freeze_depth++;
+       freeze = !q->mq_freeze_depth++;
        spin_unlock_irq(q->queue_lock);
 
-       percpu_ref_kill(&q->mq_usage_counter);
-       blk_mq_run_queues(q, false);
+       if (freeze) {
+               percpu_ref_kill(&q->mq_usage_counter);
+               blk_mq_run_queues(q, false);
+       }
        wait_event(q->mq_freeze_wq, percpu_ref_is_zero(&q->mq_usage_counter));
 }
 
 static void blk_mq_unfreeze_queue(struct request_queue *q)
 {
-       bool wake = false;
+       bool wake;
 
        spin_lock_irq(q->queue_lock);
        wake = !--q->mq_freeze_depth;
@@ -1580,7 +1584,7 @@ static int blk_mq_init_hw_queues(struct request_queue *q,
                hctx->tags = set->tags[i];
 
                /*
-                * Allocate space for all possible cpus to avoid allocation in
+                * Allocate space for all possible cpus to avoid allocation at
                 * runtime
                 */
                hctx->ctxs = kmalloc_node(nr_cpu_ids * sizeof(void *),
@@ -1668,8 +1672,8 @@ static void blk_mq_map_swqueue(struct request_queue *q)
 
        queue_for_each_hw_ctx(q, hctx, i) {
                /*
-                * If not software queues are mapped to this hardware queue,
-                * disable it and free the request entries
+                * If no software queues are mapped to this hardware queue,
+                * disable it and free the request entries.
                 */
                if (!hctx->nr_ctx) {
                        struct blk_mq_tag_set *set = q->tag_set;