block, cfq: move cfqd->cic_index to q->id

cfq allocates per-queue id using ida and uses it to index cic radix
tree from io_context.  Move it to q->id and allocate on queue init and
free on queue release.  This simplifies cfq a bit and will allow for
further improvements of io context life-cycle management.

This patch doesn't introduce any functional difference.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 16 insertions, 8 deletions

diff --git a/block/blk-core.c b/block/blk-core.c
index 30add45a87ef..af7301581172 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -39,6 +39,8 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(block_bio_remap);
 EXPORT_TRACEPOINT_SYMBOL_GPL(block_rq_remap);
 EXPORT_TRACEPOINT_SYMBOL_GPL(block_bio_complete);
 
+DEFINE_IDA(blk_queue_ida);
+
 /*
  * For the allocated request tables
  */
@@ -474,6 +476,10 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
         if (!q)
                 return NULL;
 
+        q->id = ida_simple_get(&blk_queue_ida, 0, 0, GFP_KERNEL);
+        if (q->id < 0)
+                goto fail_q;
+
         q->backing_dev_info.ra_pages =
                         (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
         q->backing_dev_info.state = 0;
@@ -481,15 +487,11 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
         q->backing_dev_info.name = "block";
 
         err = bdi_init(&q->backing_dev_info);
-        if (err) {
-                kmem_cache_free(blk_requestq_cachep, q);
-                return NULL;
-        }
+        if (err)
+                goto fail_id;
 
-        if (blk_throtl_init(q)) {
-                kmem_cache_free(blk_requestq_cachep, q);
-                return NULL;
-        }
+        if (blk_throtl_init(q))
+                goto fail_id;
 
         setup_timer(&q->backing_dev_info.laptop_mode_wb_timer,
                     laptop_mode_timer_fn, (unsigned long) q);
@@ -512,6 +514,12 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
         q->queue_lock = &q->__queue_lock;
 
         return q;
+
+fail_id:
+        ida_simple_remove(&blk_queue_ida, q->id);
+fail_q:
+        kmem_cache_free(blk_requestq_cachep, q);
+        return NULL;
 }
 EXPORT_SYMBOL(blk_alloc_queue_node);