EVMS core 4/4: evms_biosplit.h

diff -Naur linux-2.5.40/include/linux/evms/evms_biosplit.h linux-2.5.40-evms/include/linux/evms/evms_biosplit.h
@@ -0,0 +1,125 @@
+/* -*- linux-c -*- */
+/*
+ *
+ *
+ *   Copyright (c) International Business Machines  Corp., 2000
+ *
+ *   This program is free software;  you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
+ *   the GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program;  if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ *
+ */
+/*
+ *
+ * linux/include/linux/evms/evms_biosplit.h
+ *
+ * BIO splitting header file
+ *
+ */
+#include <linux/mempool.h>
+
+static mempool_t *my_bio_split_pool, *my_bio_pool;
+static kmem_cache_t *my_bio_split_slab, *my_bio_pool_slab;
+
+/**
+ * slab_pool_alloc
+ * @gfp_mask:	GFP allocation flag
+ * @data:	mempool prototype required fields
+ *
+ * mempool allocate function
+ **/
+static void *
+slab_pool_alloc(int gfp_mask, void *data)
+{
+	return kmem_cache_alloc(data, gfp_mask);
+}
+
+/**
+ * slab_pool_free
+ * @ptr:	mempool prototype required fields
+ * @data:	mempool prototype required fields
+ *
+ * mempool free function
+ **/
+static void
+slab_pool_free(void *ptr, void *data)
+{
+	kmem_cache_free(data, ptr);
+}
+
+/** bio_cache_ctor - initializes bio elements
+ * @foo:	ptr to element
+ * @cachep:	ptr to slab cache
+ * @flags:	slab flags
+ *
+ * this function initializes the bi_io_vec field in the
+ * bio's allocates from our private bio pool.    
+ **/   
+#define EVMS_BIO_VEC_SIZE (sizeof(struct bio_vec) * (BIO_MAX_PAGES+1))
+static void   bio_cache_ctor(void * foo, kmem_cache_t * cachep, unsigned long flags)   
+{
+	if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == 
+	              SLAB_CTOR_CONSTRUCTOR) {
+		struct bio *bio = (struct bio *)foo;
+		memset(bio, 0, (sizeof(*bio) + EVMS_BIO_VEC_SIZE));
+		bio->bi_io_vec = (struct bio_vec *)((char *)bio + sizeof(*bio));
+	}
+}
+
+static void
+bio_split_setup(char * split_name, char * bio_name)
+{
+	/* initialize MY bio split record pool */
+	my_bio_split_slab = kmem_cache_create(split_name,
+						sizeof
+						(struct bio_split_cb),
+						0, SLAB_HWCACHE_ALIGN,
+                                                NULL, NULL);
+	if (!my_bio_split_slab) {
+		panic("unable to create EVMS Bio Split cache.");
+	}
+	my_bio_split_pool = mempool_create(256,
+					     slab_pool_alloc,
+					     slab_pool_free,
+					     my_bio_split_slab);
+	if (!my_bio_split_pool) {
+		panic("unable to create EVMS Bio Split pool.");
+	}
+
+	/* initialize MY bio pool */
+	my_bio_pool_slab = kmem_cache_create(bio_name,
+                                             (sizeof (struct bio) +
+					     EVMS_BIO_VEC_SIZE),
+					     0, SLAB_HWCACHE_ALIGN,
+					     bio_cache_ctor, NULL);
+	if (!my_bio_pool_slab) {
+		panic("unable to create EVMS Bio cache.");
+	}
+	my_bio_pool = mempool_create(256,
+	       			     slab_pool_alloc,
+	       			     slab_pool_free,
+	       			     my_bio_pool_slab);
+	if (!my_bio_pool) {
+		panic("unable to create EVMS Bio pool.");
+	}
+}
+
+static void
+bio_split_remove(void)
+{
+	mempool_destroy(my_bio_pool);
+	kmem_cache_destroy(my_bio_pool_slab);
+	mempool_destroy(my_bio_split_pool);
+	kmem_cache_destroy(my_bio_split_slab);
+}