[PATCH 03/30] blk-mq: add the blk_mq_alloc_disk APIs

Christoph Hellwig
2021-06-02T06:58:05Z

Add a new API to allocate a gendisk including the request_queue for use
with blk-mq based drivers. This is to avoid boilerplate code in drivers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
block/blk-mq.c | 19 +++++++++++++++++++
include/linux/blk-mq.h | 12 ++++++++++++
2 files changed, 31 insertions(+)

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 6112741e1ff9..1e6036e6fd66 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -3137,6 +3137,25 @@ struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
}
EXPORT_SYMBOL(blk_mq_init_queue);

+struct gendisk *__blk_mq_alloc_disk(struct blk_mq_tag_set *set, void *queuedata)
+{
+ struct request_queue *q;
+ struct gendisk *disk;
+
+ q = blk_mq_init_queue_data(set, queuedata);
+ if (IS_ERR(q))
+ return ERR_CAST(q);
+
+ disk = __alloc_disk_node(0, set->numa_node);
+ if (!disk) {
+ blk_cleanup_queue(q);
+ return ERR_PTR(-ENOMEM);
+ }
+ disk->queue = q;
+ return disk;
+}
+EXPORT_SYMBOL(__blk_mq_alloc_disk);
+
/*
* Helper for setting up a queue with mq ops, given queue depth, and
* the passed in mq ops flags.
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 73750b2838d2..f496c6c5b5d2 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -426,6 +426,18 @@ enum {
((policy & ((1 << BLK_MQ_F_ALLOC_POLICY_BITS) - 1)) \
<< BLK_MQ_F_ALLOC_POLICY_START_BIT)

+#define blk_mq_alloc_disk(set, queuedata) \
+({ \
+ static struct lock_class_key __key; \
+ struct gendisk *__disk = __blk_mq_alloc_disk(set, queuedata); \
+ \
+ if (__disk) \
+ lockdep_init_map(&__disk->lockdep_map, \
+ "(bio completion)", &__key, 0); \
+ __disk; \
+})
+struct gendisk *__blk_mq_alloc_disk(struct blk_mq_tag_set *set,
+ void *queuedata);
struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *);
struct request_queue *blk_mq_init_queue_data(struct blk_mq_tag_set *set,
void *queuedata);