Merge branch 'for-4.4/core' of git://git.kernel.dk/linux-block

[uclinux-h8/linux.git] / block / blk-mq.c

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 85f0143..309e410 100644 (file)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -9,6 +9,7 @@
 #include <linux/backing-dev.h>
 #include <linux/bio.h>
 #include <linux/blkdev.h>
+#include <linux/kmemleak.h>
 #include <linux/mm.h>
 #include <linux/init.h>
 #include <linux/slab.h>
@@ -989,18 +990,25 @@ void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs)
 }
 EXPORT_SYMBOL(blk_mq_delay_queue);
 
-static void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx,
-                                   struct request *rq, bool at_head)
+static inline void __blk_mq_insert_req_list(struct blk_mq_hw_ctx *hctx,
+                                           struct blk_mq_ctx *ctx,
+                                           struct request *rq,
+                                           bool at_head)
 {
-       struct blk_mq_ctx *ctx = rq->mq_ctx;
-
        trace_block_rq_insert(hctx->queue, rq);
 
        if (at_head)
                list_add(&rq->queuelist, &ctx->rq_list);
        else
                list_add_tail(&rq->queuelist, &ctx->rq_list);
+}
 
+static void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx,
+                                   struct request *rq, bool at_head)
+{
+       struct blk_mq_ctx *ctx = rq->mq_ctx;
+
+       __blk_mq_insert_req_list(hctx, ctx, rq, at_head);
        blk_mq_hctx_mark_pending(hctx, ctx);
 }
 
@@ -1056,8 +1064,9 @@ static void blk_mq_insert_requests(struct request_queue *q,
                rq = list_first_entry(list, struct request, queuelist);
                list_del_init(&rq->queuelist);
                rq->mq_ctx = ctx;
-               __blk_mq_insert_request(hctx, rq, false);
+               __blk_mq_insert_req_list(hctx, ctx, rq, false);
        }
+       blk_mq_hctx_mark_pending(hctx, ctx);
        spin_unlock(&ctx->lock);
 
        blk_mq_run_hw_queue(hctx, from_schedule);
@@ -1139,7 +1148,7 @@ static inline bool blk_mq_merge_queue_io(struct blk_mq_hw_ctx *hctx,
                                         struct blk_mq_ctx *ctx,
                                         struct request *rq, struct bio *bio)
 {
-       if (!hctx_allow_merges(hctx)) {
+       if (!hctx_allow_merges(hctx) || !bio_mergeable(bio)) {
                blk_mq_bio_to_request(rq, bio);
                spin_lock(&ctx->lock);
 insert_rq:
@@ -1267,9 +1276,12 @@ static void blk_mq_make_request(struct request_queue *q, struct bio *bio)
 
        blk_queue_split(q, &bio, q->bio_split);
 
-       if (!is_flush_fua && !blk_queue_nomerges(q) &&
-           blk_attempt_plug_merge(q, bio, &request_count, &same_queue_rq))
-               return;
+       if (!is_flush_fua && !blk_queue_nomerges(q)) {
+               if (blk_attempt_plug_merge(q, bio, &request_count,
+                                          &same_queue_rq))
+                       return;
+       } else
+               request_count = blk_plug_queued_count(q);
 
        rq = blk_mq_map_request(q, bio, &data);
        if (unlikely(!rq))
@@ -1376,7 +1388,7 @@ static void blk_sq_make_request(struct request_queue *q, struct bio *bio)
        plug = current->plug;
        if (plug) {
                blk_mq_bio_to_request(rq, bio);
-               if (list_empty(&plug->mq_list))
+               if (!request_count)
                        trace_block_plug(q);
                else if (request_count >= BLK_MAX_REQUEST_COUNT) {
                        blk_flush_plug_list(plug, false);
@@ -1430,6 +1442,11 @@ static void blk_mq_free_rq_map(struct blk_mq_tag_set *set,
        while (!list_empty(&tags->page_list)) {
                page = list_first_entry(&tags->page_list, struct page, lru);
                list_del_init(&page->lru);
+               /*
+                * Remove kmemleak object previously allocated in
+                * blk_mq_init_rq_map().
+                */
+               kmemleak_free(page_address(page));
                __free_pages(page, page->private);
        }
 
@@ -1502,6 +1519,11 @@ static struct blk_mq_tags *blk_mq_init_rq_map(struct blk_mq_tag_set *set,
                list_add_tail(&page->lru, &tags->page_list);
 
                p = page_address(page);
+               /*
+                * Allow kmemleak to scan these pages as they contain pointers
+                * to additional allocations like via ops->init_request().
+                */
+               kmemleak_alloc(p, order_to_size(this_order), 1, GFP_KERNEL);
                entries_per_page = order_to_size(this_order) / rq_size;
                to_do = min(entries_per_page, set->queue_depth - i);
                left -= to_do * rq_size;
@@ -1673,7 +1695,7 @@ static int blk_mq_init_hctx(struct request_queue *q,
        INIT_LIST_HEAD(&hctx->dispatch);
        hctx->queue = q;
        hctx->queue_num = hctx_idx;
-       hctx->flags = set->flags;
+       hctx->flags = set->flags & ~BLK_MQ_F_TAG_SHARED;
 
        blk_mq_init_cpu_notifier(&hctx->cpu_notifier,
                                        blk_mq_hctx_notify, hctx);
@@ -1860,27 +1882,26 @@ static void blk_mq_map_swqueue(struct request_queue *q,
        }
 }
 
-static void blk_mq_update_tag_set_depth(struct blk_mq_tag_set *set)
+static void queue_set_hctx_shared(struct request_queue *q, bool shared)
 {
        struct blk_mq_hw_ctx *hctx;
-       struct request_queue *q;
-       bool shared;
        int i;
 
-       if (set->tag_list.next == set->tag_list.prev)
-               shared = false;
-       else
-               shared = true;
+       queue_for_each_hw_ctx(q, hctx, i) {
+               if (shared)
+                       hctx->flags |= BLK_MQ_F_TAG_SHARED;
+               else
+                       hctx->flags &= ~BLK_MQ_F_TAG_SHARED;
+       }
+}
+
+static void blk_mq_update_tag_set_depth(struct blk_mq_tag_set *set, bool shared)
+{
+       struct request_queue *q;
 
        list_for_each_entry(q, &set->tag_list, tag_set_list) {
                blk_mq_freeze_queue(q);
-
-               queue_for_each_hw_ctx(q, hctx, i) {
-                       if (shared)
-                               hctx->flags |= BLK_MQ_F_TAG_SHARED;
-                       else
-                               hctx->flags &= ~BLK_MQ_F_TAG_SHARED;
-               }
+               queue_set_hctx_shared(q, shared);
                blk_mq_unfreeze_queue(q);
        }
 }
@@ -1891,7 +1912,12 @@ static void blk_mq_del_queue_tag_set(struct request_queue *q)
 
        mutex_lock(&set->tag_list_lock);
        list_del_init(&q->tag_set_list);
-       blk_mq_update_tag_set_depth(set);
+       if (list_is_singular(&set->tag_list)) {
+               /* just transitioned to unshared */
+               set->flags &= ~BLK_MQ_F_TAG_SHARED;
+               /* update existing queue */
+               blk_mq_update_tag_set_depth(set, false);
+       }
        mutex_unlock(&set->tag_list_lock);
 }
 
@@ -1901,8 +1927,17 @@ static void blk_mq_add_queue_tag_set(struct blk_mq_tag_set *set,
        q->tag_set = set;
 
        mutex_lock(&set->tag_list_lock);
+
+       /* Check to see if we're transitioning to shared (from 1 to 2 queues). */
+       if (!list_empty(&set->tag_list) && !(set->flags & BLK_MQ_F_TAG_SHARED)) {
+               set->flags |= BLK_MQ_F_TAG_SHARED;
+               /* update existing queue */
+               blk_mq_update_tag_set_depth(set, true);
+       }
+       if (set->flags & BLK_MQ_F_TAG_SHARED)
+               queue_set_hctx_shared(q, true);
        list_add_tail(&q->tag_set_list, &set->tag_list);
-       blk_mq_update_tag_set_depth(set);
+
        mutex_unlock(&set->tag_list_lock);
 }