From 1117449276bb909b029ed0b9ba13f53e4784db9d Mon Sep 17 00:00:00 2001 From: NeilBrown 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 Signed-off-by: J. Bruce Fields --- 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