[patch 03/23] bufferhead: Revert constructor removal

Christoph Lameter
2007-11-07T01:13:37Z

[-- 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

--