Staging: DST: optimize bio allocation.

Use bio prepend feature as suggested by Jens Axboe.

Signed-off-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/staging/dst/export.c b/drivers/staging/dst/export.c
index 122fe75..80ae4eb 100644 (file)
--- a/drivers/staging/dst/export.c
+++ b/drivers/staging/dst/export.c
@@ -33,7 +33,7 @@ int __init dst_export_init(void)
 {
        int err = -ENOMEM;
 
-       dst_bio_set = bioset_create(32, 32);
+       dst_bio_set = bioset_create(32, sizeof(struct dst_export_priv));
        if (!dst_bio_set)
                goto err_out_exit;
 
@@ -424,12 +424,8 @@ static void dst_bio_destructor(struct bio *bio)
                __free_page(bv->bv_page);
        }
 
-       if (priv) {
-               struct dst_node *n = priv->state->node;
-
+       if (priv)
                dst_state_put(priv->state);
-               mempool_free(priv, n->trans_pool);
-       }
        bio_free(bio, dst_bio_set);
 }
 
@@ -555,11 +551,8 @@ int dst_process_io(struct dst_state *st)
                        dst_bio_set);
        if (!bio)
                goto err_out_exit;
-       bio->bi_private = NULL;
 
-       priv = mempool_alloc(st->node->trans_pool, GFP_KERNEL);
-       if (!priv)
-               goto err_out_free;
+       priv = (struct dst_export_priv *)(((void *)bio) - sizeof (struct dst_export_priv));
 
        priv->state = dst_state_get(st);
        priv->bio = bio;