Commit 8fbf26ad authored by Kiyoshi Ueda's avatar Kiyoshi Ueda Committed by Alasdair G Kergon
Browse files

dm request: add caches 



This patch prepares some kmem_caches for request-based dm.

Signed-off-by: default avatarKiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: default avatarJun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
parent 23d39f63

drivers/md/dm.c

+40 −1
Original line number Diff line number Diff line
@@ -32,6 +32,7 @@ static unsigned int _major = 0; 


static DEFINE_SPINLOCK(_minor_lock);

/*

 * For bio-based dm.

 * One of these is allocated per bio.

 */

struct dm_io {
@@ -43,6 +44,7 @@ struct dm_io { 
};



/*

 * For bio-based dm.

 * One of these is allocated per target within a bio.  Hopefully

 * this will be simplified out one day.

 */
@@ -54,6 +56,27 @@ struct dm_target_io { 


DEFINE_TRACE(block_bio_complete);



/*

 * For request-based dm.

 * One of these is allocated per request.

 */

struct dm_rq_target_io {

	struct mapped_device *md;

	struct dm_target *ti;

	struct request *orig, clone;

	int error;

	union map_info info;

};



/*

 * For request-based dm.

 * One of these is allocated per bio.

 */

struct dm_rq_clone_bio_info {

	struct bio *orig;

	struct request *rq;

};



union map_info *dm_get_mapinfo(struct bio *bio)

{

	if (bio && bio->bi_private)
@@ -149,6 +172,8 @@ struct mapped_device { 
#define MIN_IOS 256

static struct kmem_cache *_io_cache;

static struct kmem_cache *_tio_cache;

static struct kmem_cache *_rq_tio_cache;

static struct kmem_cache *_rq_bio_info_cache;



static int __init local_init(void)

{
@@ -164,9 +189,17 @@ static int __init local_init(void) 
	if (!_tio_cache)

		goto out_free_io_cache;



	_rq_tio_cache = KMEM_CACHE(dm_rq_target_io, 0);

	if (!_rq_tio_cache)

		goto out_free_tio_cache;



	_rq_bio_info_cache = KMEM_CACHE(dm_rq_clone_bio_info, 0);

	if (!_rq_bio_info_cache)

		goto out_free_rq_tio_cache;



	r = dm_uevent_init();

	if (r)

		goto out_free_tio_cache;

		goto out_free_rq_bio_info_cache;



	_major = major;

	r = register_blkdev(_major, _name);
@@ -180,6 +213,10 @@ static int __init local_init(void) 


out_uevent_exit:

	dm_uevent_exit();

out_free_rq_bio_info_cache:

	kmem_cache_destroy(_rq_bio_info_cache);

out_free_rq_tio_cache:

	kmem_cache_destroy(_rq_tio_cache);

out_free_tio_cache:

	kmem_cache_destroy(_tio_cache);

out_free_io_cache:
@@ -190,6 +227,8 @@ out_free_io_cache: 


static void local_exit(void)

{

	kmem_cache_destroy(_rq_bio_info_cache);

	kmem_cache_destroy(_rq_tio_cache);

	kmem_cache_destroy(_tio_cache);

	kmem_cache_destroy(_io_cache);

	unregister_blkdev(_major, _name);