[GFS2] Allocate gfs2_rgrpd from slab memory

This patch moves the gfs2_rgrpd structure to its own slab
memory.  This makes it easier to control and monitor, and
yields less memory fragmentation.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

fs/gfs2/main.c

@@ -89,6 +89,12 @@ static int __init init_gfs2_fs(void)
 	if (!gfs2_bufdata_cachep)
 		goto fail;
 
+	gfs2_rgrpd_cachep = kmem_cache_create("gfs2_rgrpd",
+					      sizeof(struct gfs2_rgrpd),
+					      0, 0, NULL);
+	if (!gfs2_rgrpd_cachep)
+		goto fail;
+
 	error = register_filesystem(&gfs2_fs_type);
 	if (error)
 		goto fail;
@@ -108,6 +114,9 @@ fail_unregister:
 fail:
 	gfs2_glock_exit();
 
+	if (gfs2_rgrpd_cachep)
+		kmem_cache_destroy(gfs2_rgrpd_cachep);
+
 	if (gfs2_bufdata_cachep)
 		kmem_cache_destroy(gfs2_bufdata_cachep);
 
@@ -133,6 +142,7 @@ static void __exit exit_gfs2_fs(void)
 	unregister_filesystem(&gfs2_fs_type);
 	unregister_filesystem(&gfs2meta_fs_type);
 
+	kmem_cache_destroy(gfs2_rgrpd_cachep);
 	kmem_cache_destroy(gfs2_bufdata_cachep);
 	kmem_cache_destroy(gfs2_inode_cachep);
 	kmem_cache_destroy(gfs2_glock_cachep);

fs/gfs2/rgrp.c

@@ -353,7 +353,7 @@ static void clear_rgrpdi(struct gfs2_sbd *sdp)
 		}
 
 		kfree(rgd->rd_bits);
-		kfree(rgd);
+		kmem_cache_free(gfs2_rgrpd_cachep, rgd);
 	}
 }
 
@@ -516,7 +516,7 @@ static int read_rindex_entry(struct gfs2_inode *ip,
 		return error;
 	}
 
-	rgd = kzalloc(sizeof(struct gfs2_rgrpd), GFP_NOFS);
+	rgd = kmem_cache_zalloc(gfs2_rgrpd_cachep, GFP_NOFS);
 	error = -ENOMEM;
 	if (!rgd)
 		return error;

fs/gfs2/util.c

@@ -25,6 +25,7 @@
 struct kmem_cache *gfs2_glock_cachep __read_mostly;
 struct kmem_cache *gfs2_inode_cachep __read_mostly;
 struct kmem_cache *gfs2_bufdata_cachep __read_mostly;
+struct kmem_cache *gfs2_rgrpd_cachep __read_mostly;
 
 void gfs2_assert_i(struct gfs2_sbd *sdp)
 {

fs/gfs2/util.h

@@ -147,6 +147,7 @@ gfs2_io_error_bh_i((sdp), (bh), __FUNCTION__, __FILE__, __LINE__);
 extern struct kmem_cache *gfs2_glock_cachep;
 extern struct kmem_cache *gfs2_inode_cachep;
 extern struct kmem_cache *gfs2_bufdata_cachep;
+extern struct kmem_cache *gfs2_rgrpd_cachep;
 
 static inline unsigned int gfs2_tune_get_i(struct gfs2_tune *gt,
 					   unsigned int *p)