[patch 03/23] bufferhead: Revert constructor removal

[Christoph Lameter <clameter@sgi.com>]

[-- Attachment #1: 0015-slab_defrag_buffer_head_revert.patch --]
[-- Type: text/plain, Size: 1751 bytes --]

The constructor for buffer_head slabs was removed recently. We need
the constructor in order to insure that slab objects always have a definite
state even before we allocated them.

[This patch is already in mm]

Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Christoph Lameter <clameter@sgi.com>

---
 fs/buffer.c |   19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

Index: linux-2.6/fs/buffer.c
===================================================================
--- linux-2.6.orig/fs/buffer.c	2007-10-25 18:28:40.000000000 -0700
+++ linux-2.6/fs/buffer.c	2007-11-06 12:55:45.000000000 -0800
@@ -3169,10 +3169,9 @@ static void recalc_bh_state(void)
 	
 struct buffer_head *alloc_buffer_head(gfp_t gfp_flags)
 {
-	struct buffer_head *ret = kmem_cache_zalloc(bh_cachep,
+	struct buffer_head *ret = kmem_cache_alloc(bh_cachep,
 				set_migrateflags(gfp_flags, __GFP_RECLAIMABLE));
 	if (ret) {
-		INIT_LIST_HEAD(&ret->b_assoc_buffers);
 		get_cpu_var(bh_accounting).nr++;
 		recalc_bh_state();
 		put_cpu_var(bh_accounting);
@@ -3213,12 +3212,24 @@ static int buffer_cpu_notify(struct noti
 	return NOTIFY_OK;
 }
 
+static void
+init_buffer_head(void *data, struct kmem_cache *cachep, unsigned long flags)
+{
+	struct buffer_head * bh = (struct buffer_head *)data;
+
+	memset(bh, 0, sizeof(*bh));
+	INIT_LIST_HEAD(&bh->b_assoc_buffers);
+}
+
 void __init buffer_init(void)
 {
 	int nrpages;
 
-	bh_cachep = KMEM_CACHE(buffer_head,
-			SLAB_RECLAIM_ACCOUNT|SLAB_PANIC|SLAB_MEM_SPREAD);
+	bh_cachep = kmem_cache_create("buffer_head",
+			sizeof(struct buffer_head), 0,
+				(SLAB_RECLAIM_ACCOUNT|SLAB_PANIC|
+				SLAB_MEM_SPREAD),
+				init_buffer_head);
 
 	/*
 	 * Limit the bh occupancy to 10% of ZONE_NORMAL

--