[PATCH 08/15] block: pass a queue_limits argument to blk_alloc_queue

[Christoph Hellwig]

Pass a queue_limits to blk_alloc_queue and apply it after validating and
capping the values using blk_validate_limits.  This will allow allocating
queues with valid queue limits instead of setting the values one at a
time later.

Signed-off-by: Christoph Hellwig <hch at lst.de>
Reviewed-by: Damien Le Moal <dlemoal at kernel.org>
---
 block/blk-core.c | 26 ++++++++++++++++++--------
 block/blk-mq.c   |  7 ++++---
 block/blk.h      |  2 +-
 block/genhd.c    |  5 +++--
 4 files changed, 26 insertions(+), 14 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index cb56724a8dfb25..a16b5abdbbf56f 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -394,24 +394,34 @@ static void blk_timeout_work(struct work_struct *work)
 {
 }
 
-struct request_queue *blk_alloc_queue(int node_id)
+struct request_queue *blk_alloc_queue(struct queue_limits *lim, int node_id)
 {
 	struct request_queue *q;
+	int error;
 
 	q = kmem_cache_alloc_node(blk_requestq_cachep, GFP_KERNEL | __GFP_ZERO,
 				  node_id);
 	if (!q)
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 
 	q->last_merge = NULL;
 
 	q->id = ida_alloc(&blk_queue_ida, GFP_KERNEL);
-	if (q->id < 0)
+	if (q->id < 0) {
+		error = q->id;
 		goto fail_q;
+	}
 
 	q->stats = blk_alloc_queue_stats();
-	if (!q->stats)
+	if (!q->stats) {
+		error = -ENOMEM;
 		goto fail_id;
+	}
+
+	error = blk_set_default_limits(lim);
+	if (error)
+		goto fail_stats;
+	q->limits = *lim;
 
 	q->node = node_id;
 
@@ -436,12 +446,12 @@ struct request_queue *blk_alloc_queue(int node_id)
 	 * Init percpu_ref in atomic mode so that it's faster to shutdown.
 	 * See blk_register_queue() for details.
 	 */
-	if (percpu_ref_init(&q->q_usage_counter,
+	error = percpu_ref_init(&q->q_usage_counter,
 				blk_queue_usage_counter_release,
-				PERCPU_REF_INIT_ATOMIC, GFP_KERNEL))
+				PERCPU_REF_INIT_ATOMIC, GFP_KERNEL);
+	if (error)
 		goto fail_stats;
 
-	blk_set_default_limits(&q->limits);
 	q->nr_requests = BLKDEV_DEFAULT_RQ;
 
 	return q;
@@ -452,7 +462,7 @@ struct request_queue *blk_alloc_queue(int node_id)
 	ida_free(&blk_queue_ida, q->id);
 fail_q:
 	kmem_cache_free(blk_requestq_cachep, q);
-	return NULL;
+	return ERR_PTR(error);
 }
 
 /**
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 6d2f7b5caa01d8..9dd8055cc5246d 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -4086,12 +4086,13 @@ void blk_mq_release(struct request_queue *q)
 static struct request_queue *blk_mq_init_queue_data(struct blk_mq_tag_set *set,
 		void *queuedata)
 {
+	struct queue_limits lim = { };
 	struct request_queue *q;
 	int ret;
 
-	q = blk_alloc_queue(set->numa_node);
-	if (!q)
-		return ERR_PTR(-ENOMEM);
+	q = blk_alloc_queue(&lim, set->numa_node);
+	if (IS_ERR(q))
+		return q;
 	q->queuedata = queuedata;
 	ret = blk_mq_init_allocated_queue(set, q);
 	if (ret) {
diff --git a/block/blk.h b/block/blk.h
index 43c7e9180b3028..7c30e2ac8ebcd3 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -448,7 +448,7 @@ static inline void bio_release_page(struct bio *bio, struct page *page)
 		unpin_user_page(page);
 }
 
-struct request_queue *blk_alloc_queue(int node_id);
+struct request_queue *blk_alloc_queue(struct queue_limits *lim, int node_id);
 
 int disk_scan_partitions(struct gendisk *disk, blk_mode_t mode);
 
diff --git a/block/genhd.c b/block/genhd.c
index d74fb5b4ae6818..7a8fd57c51f73c 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -1393,11 +1393,12 @@ struct gendisk *__alloc_disk_node(struct request_queue *q, int node_id,
 
 struct gendisk *__blk_alloc_disk(int node, struct lock_class_key *lkclass)
 {
+	struct queue_limits lim = { };
 	struct request_queue *q;
 	struct gendisk *disk;
 
-	q = blk_alloc_queue(node);
-	if (!q)
+	q = blk_alloc_queue(&lim, node);
+	if (IS_ERR(q))
 		return NULL;
 
 	disk = __alloc_disk_node(q, node, lkclass);
-- 
2.39.2