From 1117449276bb909b029ed0b9ba13f53e4784db9d Mon Sep 17 00:00:00 2001
From: NeilBrown <neilb@suse.de>
Date: Thu, 12 Aug 2010 17:04:08 +1000
Subject: [PATCH] sunrpc/cache: change deferred-request hash table to use
hlist.
Being a hash table, hlist is the best option.
There is currently some ugliness were we treat "->next == NULL" as
a special case to avoid having to initialise the whole array.
This change nicely gets rid of that case.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---
include/linux/sunrpc/cache.h | 2 +-
net/sunrpc/cache.c | 28 ++++++++++------------------
2 files changed, 11 insertions(+), 19 deletions(-)
diff --git a/include/linux/sunrpc/cache.h b/include/linux/sunrpc/cache.h
index 52a7d7224e90..03496357f455 100644
--- a/include/linux/sunrpc/cache.h
+++ b/include/linux/sunrpc/cache.h
@@ -133,7 +133,7 @@ struct cache_req {
* delayed awaiting cache-fill
*/
struct cache_deferred_req {
- struct list_head hash; /* on hash chain */
+ struct hlist_node hash; /* on hash chain */
struct list_head recent; /* on fifo */
struct cache_head *item; /* cache item we wait on */
void *owner; /* we might need to discard all defered requests
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
index ca7c621cd975..2a8405194056 100644
--- a/net/sunrpc/cache.c
+++ b/net/sunrpc/cache.c
@@ -506,13 +506,13 @@ EXPORT_SYMBOL_GPL(cache_purge);
static DEFINE_SPINLOCK(cache_defer_lock);
static LIST_HEAD(cache_defer_list);
-static struct list_head cache_defer_hash[DFR_HASHSIZE];
+static struct hlist_head cache_defer_hash[DFR_HASHSIZE];
static int cache_defer_cnt;
static void __unhash_deferred_req(struct cache_deferred_req *dreq)
{
list_del_init(&dreq->recent);
- list_del_init(&dreq->hash);
+ hlist_del_init(&dreq->hash);
cache_defer_cnt--;
}
@@ -521,9 +521,7 @@ static void __hash_deferred_req(struct cache_deferred_req *dreq, struct cache_he
int hash = DFR_HASH(item);
list_add(&dreq->recent, &cache_defer_list);
- if (cache_defer_hash[hash].next == NULL)
- INIT_LIST_HEAD(&cache_defer_hash[hash]);
- list_add(&dreq->hash, &cache_defer_hash[hash]);
+ hlist_add_head(&dreq->hash, &cache_defer_hash[hash]);
}
static int setup_deferral(struct cache_deferred_req *dreq, struct cache_head *item)
@@ -588,7 +586,7 @@ static int cache_wait_req(struct cache_req *req, struct cache_head *item)
* to clean up
*/
spin_lock(&cache_defer_lock);
- if (!list_empty(&sleeper.handle.hash)) {
+ if (!hlist_unhashed(&sleeper.handle.hash)) {
__unhash_deferred_req(&sleeper.handle);
spin_unlock(&cache_defer_lock);
} else {
@@ -642,24 +640,18 @@ static void cache_revisit_request(struct cache_head *item)
{
struct cache_deferred_req *dreq;
struct list_head pending;
-
- struct list_head *lp;
+ struct hlist_node *lp, *tmp;
int hash = DFR_HASH(item);
INIT_LIST_HEAD(&pending);
spin_lock(&cache_defer_lock);
- lp = cache_defer_hash[hash].next;
- if (lp) {
- while (lp != &cache_defer_hash[hash]) {
- dreq = list_entry(lp, struct cache_deferred_req, hash);
- lp = lp->next;
- if (dreq->item == item) {
- __unhash_deferred_req(dreq);
- list_add(&dreq->recent, &pending);
- }
+ hlist_for_each_entry_safe(dreq, lp, tmp, &cache_defer_hash[hash], hash)
+ if (dreq->item == item) {
+ __unhash_deferred_req(dreq);
+ list_add(&dreq->recent, &pending);
}
- }
+
spin_unlock(&cache_defer_lock);
while (!list_empty(&pending)) {
--
2.20.1