dm request: add caches

This patch prepares some kmem_caches for request-based dm.

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 8237141..4882ce7 100644 (file)
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -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);