[RFC 15/26] bufferhead: Revert constructor removal

Christoph Lameter
2007-09-01T01:48:31Z

[-- Attachment #1: 0015-slab_defrag_buffer_head_revert.patch --]
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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.

Signed-off-by: Christoph Lameter <clameter@sgi.com>

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

diff --git a/fs/buffer.c b/fs/buffer.c
index 0e5ec37..f4824d1 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -2960,9 +2960,8 @@ 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, gfp_flags);
+ struct buffer_head *ret = kmem_cache_alloc(bh_cachep, gfp_flags);
if (ret) {
- INIT_LIST_HEAD(&ret->b_assoc_buffers);
get_cpu_var(bh_accounting).nr++;
recalc_bh_state();
put_cpu_var(bh_accounting);
@@ -3003,12 +3002,24 @@ static int buffer_cpu_notify(struct notifier_block *self,
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
--
1.5.2.4

--