[PATCH V2 1/8] blk-mq: tags: define several fields of tags as pointer

[Ming Lei <ming.lei@redhat.com>]

This patch changes tags->breserved_tags, tags->bitmap_tags and
tags->active_queues as pointer, and prepares for supporting global tags.

No functional change.

Tested-by: Laurence Oberman <loberman@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
 block/bfq-iosched.c    |  4 ++--
 block/blk-mq-debugfs.c | 10 +++++-----
 block/blk-mq-tag.c     | 48 ++++++++++++++++++++++++++----------------------
 block/blk-mq-tag.h     | 10 +++++++---
 block/blk-mq.c         |  2 +-
 block/kyber-iosched.c  |  2 +-
 6 files changed, 42 insertions(+), 34 deletions(-)

diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index 47e6ec7427c4..1e1211814a57 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -534,9 +534,9 @@ static void bfq_limit_depth(unsigned int op, struct blk_mq_alloc_data *data)
 			WARN_ON_ONCE(1);
 			return;
 		}
-		bt = &tags->breserved_tags;
+		bt = tags->breserved_tags;
 	} else
-		bt = &tags->bitmap_tags;
+		bt = tags->bitmap_tags;
 
 	if (unlikely(bfqd->sb_shift != bt->sb.shift))
 		bfq_update_depths(bfqd, bt);
diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
index 21cbc1f071c6..0dfafa4b655a 100644
--- a/block/blk-mq-debugfs.c
+++ b/block/blk-mq-debugfs.c
@@ -433,14 +433,14 @@ static void blk_mq_debugfs_tags_show(struct seq_file *m,
 	seq_printf(m, "nr_tags=%u\n", tags->nr_tags);
 	seq_printf(m, "nr_reserved_tags=%u\n", tags->nr_reserved_tags);
 	seq_printf(m, "active_queues=%d\n",
-		   atomic_read(&tags->active_queues));
+		   atomic_read(tags->active_queues));
 
 	seq_puts(m, "\nbitmap_tags:\n");
-	sbitmap_queue_show(&tags->bitmap_tags, m);
+	sbitmap_queue_show(tags->bitmap_tags, m);
 
 	if (tags->nr_reserved_tags) {
 		seq_puts(m, "\nbreserved_tags:\n");
-		sbitmap_queue_show(&tags->breserved_tags, m);
+		sbitmap_queue_show(tags->breserved_tags, m);
 	}
 }
 
@@ -471,7 +471,7 @@ static int hctx_tags_bitmap_show(void *data, struct seq_file *m)
 	if (res)
 		goto out;
 	if (hctx->tags)
-		sbitmap_bitmap_show(&hctx->tags->bitmap_tags.sb, m);
+		sbitmap_bitmap_show(&hctx->tags->bitmap_tags->sb, m);
 	mutex_unlock(&q->sysfs_lock);
 
 out:
@@ -505,7 +505,7 @@ static int hctx_sched_tags_bitmap_show(void *data, struct seq_file *m)
 	if (res)
 		goto out;
 	if (hctx->sched_tags)
-		sbitmap_bitmap_show(&hctx->sched_tags->bitmap_tags.sb, m);
+		sbitmap_bitmap_show(&hctx->sched_tags->bitmap_tags->sb, m);
 	mutex_unlock(&q->sysfs_lock);
 
 out:
diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index 336dde07b230..571797dc36cb 100644
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -18,7 +18,7 @@ bool blk_mq_has_free_tags(struct blk_mq_tags *tags)
 	if (!tags)
 		return true;
 
-	return sbitmap_any_bit_clear(&tags->bitmap_tags.sb);
+	return sbitmap_any_bit_clear(&tags->bitmap_tags->sb);
 }
 
 /*
@@ -28,7 +28,7 @@ bool __blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx)
 {
 	if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state) &&
 	    !test_and_set_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state))
-		atomic_inc(&hctx->tags->active_queues);
+		atomic_inc(hctx->tags->active_queues);
 
 	return true;
 }
@@ -38,9 +38,9 @@ bool __blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx)
  */
 void blk_mq_tag_wakeup_all(struct blk_mq_tags *tags, bool include_reserve)
 {
-	sbitmap_queue_wake_all(&tags->bitmap_tags);
+	sbitmap_queue_wake_all(tags->bitmap_tags);
 	if (include_reserve)
-		sbitmap_queue_wake_all(&tags->breserved_tags);
+		sbitmap_queue_wake_all(tags->breserved_tags);
 }
 
 /*
@@ -54,7 +54,7 @@ void __blk_mq_tag_idle(struct blk_mq_hw_ctx *hctx)
 	if (!test_and_clear_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state))
 		return;
 
-	atomic_dec(&tags->active_queues);
+	atomic_dec(tags->active_queues);
 
 	blk_mq_tag_wakeup_all(tags, false);
 }
@@ -79,7 +79,7 @@ static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx,
 	if (bt->sb.depth == 1)
 		return true;
 
-	users = atomic_read(&hctx->tags->active_queues);
+	users = atomic_read(hctx->tags->active_queues);
 	if (!users)
 		return true;
 
@@ -117,10 +117,10 @@ unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data)
 			WARN_ON_ONCE(1);
 			return BLK_MQ_TAG_FAIL;
 		}
-		bt = &tags->breserved_tags;
+		bt = tags->breserved_tags;
 		tag_offset = 0;
 	} else {
-		bt = &tags->bitmap_tags;
+		bt = tags->bitmap_tags;
 		tag_offset = tags->nr_reserved_tags;
 	}
 
@@ -165,9 +165,9 @@ unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data)
 		data->hctx = blk_mq_map_queue(data->q, data->ctx->cpu);
 		tags = blk_mq_tags_from_data(data);
 		if (data->flags & BLK_MQ_REQ_RESERVED)
-			bt = &tags->breserved_tags;
+			bt = tags->breserved_tags;
 		else
-			bt = &tags->bitmap_tags;
+			bt = tags->bitmap_tags;
 
 		finish_wait(&ws->wait, &wait);
 		ws = bt_wait_ptr(bt, data->hctx);
@@ -189,10 +189,10 @@ void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, struct blk_mq_tags *tags,
 		const int real_tag = tag - tags->nr_reserved_tags;
 
 		BUG_ON(real_tag >= tags->nr_tags);
-		sbitmap_queue_clear(&tags->bitmap_tags, real_tag, ctx->cpu);
+		sbitmap_queue_clear(tags->bitmap_tags, real_tag, ctx->cpu);
 	} else {
 		BUG_ON(tag >= tags->nr_reserved_tags);
-		sbitmap_queue_clear(&tags->breserved_tags, tag, ctx->cpu);
+		sbitmap_queue_clear(tags->breserved_tags, tag, ctx->cpu);
 	}
 }
 
@@ -283,8 +283,8 @@ static void blk_mq_all_tag_busy_iter(struct blk_mq_tags *tags,
 		busy_tag_iter_fn *fn, void *priv)
 {
 	if (tags->nr_reserved_tags)
-		bt_tags_for_each(tags, &tags->breserved_tags, fn, priv, true);
-	bt_tags_for_each(tags, &tags->bitmap_tags, fn, priv, false);
+		bt_tags_for_each(tags, tags->breserved_tags, fn, priv, true);
+	bt_tags_for_each(tags, tags->bitmap_tags, fn, priv, false);
 }
 
 void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset,
@@ -346,8 +346,8 @@ void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_iter_fn *fn,
 			continue;
 
 		if (tags->nr_reserved_tags)
-			bt_for_each(hctx, &tags->breserved_tags, fn, priv, true);
-		bt_for_each(hctx, &tags->bitmap_tags, fn, priv, false);
+			bt_for_each(hctx, tags->breserved_tags, fn, priv, true);
+		bt_for_each(hctx, tags->bitmap_tags, fn, priv, false);
 	}
 
 }
@@ -365,15 +365,15 @@ static struct blk_mq_tags *blk_mq_init_bitmap_tags(struct blk_mq_tags *tags,
 	unsigned int depth = tags->nr_tags - tags->nr_reserved_tags;
 	bool round_robin = alloc_policy == BLK_TAG_ALLOC_RR;
 
-	if (bt_alloc(&tags->bitmap_tags, depth, round_robin, node))
+	if (bt_alloc(tags->bitmap_tags, depth, round_robin, node))
 		goto free_tags;
-	if (bt_alloc(&tags->breserved_tags, tags->nr_reserved_tags, round_robin,
+	if (bt_alloc(tags->breserved_tags, tags->nr_reserved_tags, round_robin,
 		     node))
 		goto free_bitmap_tags;
 
 	return tags;
 free_bitmap_tags:
-	sbitmap_queue_free(&tags->bitmap_tags);
+	sbitmap_queue_free(tags->bitmap_tags);
 free_tags:
 	kfree(tags);
 	return NULL;
@@ -397,13 +397,17 @@ struct blk_mq_tags *blk_mq_init_tags(unsigned int total_tags,
 	tags->nr_tags = total_tags;
 	tags->nr_reserved_tags = reserved_tags;
 
+	tags->bitmap_tags = &tags->__bitmap_tags;
+	tags->breserved_tags = &tags->__breserved_tags;
+	tags->active_queues = &tags->__active_queues;
+
 	return blk_mq_init_bitmap_tags(tags, node, alloc_policy);
 }
 
 void blk_mq_free_tags(struct blk_mq_tags *tags)
 {
-	sbitmap_queue_free(&tags->bitmap_tags);
-	sbitmap_queue_free(&tags->breserved_tags);
+	sbitmap_queue_free(tags->bitmap_tags);
+	sbitmap_queue_free(tags->breserved_tags);
 	kfree(tags);
 }
 
@@ -454,7 +458,7 @@ int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx,
 		 * Don't need (or can't) update reserved tags here, they
 		 * remain static and should never need resizing.
 		 */
-		sbitmap_queue_resize(&tags->bitmap_tags, tdepth);
+		sbitmap_queue_resize(tags->bitmap_tags, tdepth);
 	}
 
 	return 0;
diff --git a/block/blk-mq-tag.h b/block/blk-mq-tag.h
index 61deab0b5a5a..a68323fa0c02 100644
--- a/block/blk-mq-tag.h
+++ b/block/blk-mq-tag.h
@@ -11,10 +11,14 @@ struct blk_mq_tags {
 	unsigned int nr_tags;
 	unsigned int nr_reserved_tags;
 
-	atomic_t active_queues;
+	atomic_t *active_queues;
+	atomic_t __active_queues;
 
-	struct sbitmap_queue bitmap_tags;
-	struct sbitmap_queue breserved_tags;
+	struct sbitmap_queue *bitmap_tags;
+	struct sbitmap_queue *breserved_tags;
+
+	struct sbitmap_queue __bitmap_tags;
+	struct sbitmap_queue __breserved_tags;
 
 	struct request **rqs;
 	struct request **static_rqs;
diff --git a/block/blk-mq.c b/block/blk-mq.c
index df93102e2149..69d4534870af 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1136,7 +1136,7 @@ static bool blk_mq_mark_tag_wait(struct blk_mq_hw_ctx **hctx,
 		return false;
 	}
 
-	ws = bt_wait_ptr(&this_hctx->tags->bitmap_tags, this_hctx);
+	ws = bt_wait_ptr(this_hctx->tags->bitmap_tags, this_hctx);
 	add_wait_queue(&ws->wait, wait);
 
 	/*
diff --git a/block/kyber-iosched.c b/block/kyber-iosched.c
index f95c60774ce8..4adaced76382 100644
--- a/block/kyber-iosched.c
+++ b/block/kyber-iosched.c
@@ -281,7 +281,7 @@ static unsigned int kyber_sched_tags_shift(struct kyber_queue_data *kqd)
 	 * All of the hardware queues have the same depth, so we can just grab
 	 * the shift of the first one.
 	 */
-	return kqd->q->queue_hw_ctx[0]->sched_tags->bitmap_tags.sb.shift;
+	return kqd->q->queue_hw_ctx[0]->sched_tags->bitmap_tags->sb.shift;
 }
 
 static struct kyber_queue_data *kyber_queue_data_alloc(struct request_queue *q)
-- 
2.9.5