[GFS2] Use slab properly with glocks

We can take advantage of the slab allocator to ensure that all the list
heads and the spinlock (plus one or two other fields) are initialised
by slab to speed up allocation of glocks.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

1 files changed, 22 insertions, 1 deletions

diff --git a/fs/gfs2/main.c b/fs/gfs2/main.c
index c112943ee8c1..dccc4f6f503f 100644
--- a/fs/gfs2/main.c
+++ b/fs/gfs2/main.c
@@ -15,6 +15,7 @@
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/gfs2_ondisk.h>
+#include <asm/atomic.h>
 
 #include "gfs2.h"
 #include "lm_interface.h"
@@ -35,6 +36,25 @@ static void gfs2_init_inode_once(void *foo, kmem_cache_t *cachep, unsigned long
 	}
 }
 
+static void gfs2_init_glock_once(void *foo, kmem_cache_t *cachep, unsigned long flags)
+{
+	struct gfs2_glock *gl = foo;
+	if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
+	    SLAB_CTOR_CONSTRUCTOR) {
+		INIT_LIST_HEAD(&gl->gl_list);
+		spin_lock_init(&gl->gl_spin);
+		INIT_LIST_HEAD(&gl->gl_holders);
+		INIT_LIST_HEAD(&gl->gl_waiters1);
+		INIT_LIST_HEAD(&gl->gl_waiters2);
+		INIT_LIST_HEAD(&gl->gl_waiters3);
+		gl->gl_lvb = NULL;
+		atomic_set(&gl->gl_lvb_count, 0);
+		INIT_LIST_HEAD(&gl->gl_reclaim);
+		INIT_LIST_HEAD(&gl->gl_ail_list);
+		atomic_set(&gl->gl_ail_count, 0);
+	}
+}
+
 /**
  * init_gfs2_fs - Register GFS2 as a filesystem
  *
@@ -55,7 +75,8 @@ static int __init init_gfs2_fs(void)
 
 	gfs2_glock_cachep = kmem_cache_create("gfs2_glock",
 					      sizeof(struct gfs2_glock),
-					      0, 0, NULL, NULL);
+					      0, 0, 
+					      gfs2_init_glock_once, NULL);
 	if (!gfs2_glock_cachep)
 		goto fail;