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block: add blk_alloc_disk and blk_cleanup_disk APIs

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Add two new APIs to allocate and free a gendisk including the
request_queue for use with BIO based drivers.  This is to avoid
boilerplate code in drivers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20210521055116.1053587-6-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Christoph Hellwig 2021-05-21 07:50:55 +02:00 committed by Jens Axboe
parent 958229a7c5
commit f525464a80
2 changed files with 57 additions and 0 deletions
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35
block/genhd.c
View file

@ -1293,6 +1293,25 @@ struct gendisk *__alloc_disk_node(int minors, int node_id)
}
EXPORT_SYMBOL(__alloc_disk_node);
struct gendisk *__blk_alloc_disk(int node)
{
struct request_queue *q;
struct gendisk *disk;
q = blk_alloc_queue(node);
if (!q)
return NULL;
disk = __alloc_disk_node(0, node);
if (!disk) {
blk_cleanup_queue(q);
return NULL;
}
disk->queue = q;
return disk;
}
EXPORT_SYMBOL(__blk_alloc_disk);
/**
* put_disk - decrements the gendisk refcount
* @disk: the struct gendisk to decrement the refcount for
@ -1310,6 +1329,22 @@ void put_disk(struct gendisk *disk)
}
EXPORT_SYMBOL(put_disk);
/**
* blk_cleanup_disk - shutdown a gendisk allocated by blk_alloc_disk
* @disk: gendisk to shutdown
*
* Mark the queue hanging off @disk DYING, drain all pending requests, then mark
* the queue DEAD, destroy and put it and the gendisk structure.
*
* Context: can sleep
*/
void blk_cleanup_disk(struct gendisk *disk)
{
blk_cleanup_queue(disk->queue);
put_disk(disk);
}
EXPORT_SYMBOL(blk_cleanup_disk);
static void set_disk_ro_uevent(struct gendisk *gd, int ro)
{
char event[] = "DISK_RO=1";

22
include/linux/genhd.h
View file

@ -278,6 +278,28 @@ extern void put_disk(struct gendisk *disk);
#define alloc_disk(minors) alloc_disk_node(minors, NUMA_NO_NODE)
/**
* blk_alloc_disk - allocate a gendisk structure
* @node_id: numa node to allocate on
*
* Allocate and pre-initialize a gendisk structure for use with BIO based
* drivers.
*
* Context: can sleep
*/
#define blk_alloc_disk(node_id) \
({ \
struct gendisk *__disk = __blk_alloc_disk(node_id); \
static struct lock_class_key __key; \
\
if (__disk) \
lockdep_init_map(&__disk->lockdep_map, \
"(bio completion)", &__key, 0); \
__disk; \
})
struct gendisk *__blk_alloc_disk(int node);
void blk_cleanup_disk(struct gendisk *disk);
int __register_blkdev(unsigned int major, const char *name,
void (*probe)(dev_t devt));
#define register_blkdev(major, name) \