From 129e5824cd96d9289679973f0ff7c48e88d569bb Mon Sep 17 00:00:00 2001 From: Kinglong Mee Date: Mon, 27 Jul 2015 11:10:15 +0800 Subject: sunrpc: Switch to using hash list instead single list Switch using list_head for cache_head in cache_detail, it is useful of remove an cache_head entry directly from cache_detail. v8, using hash list, not head list Signed-off-by: Kinglong Mee Reviewed-by: NeilBrown Signed-off-by: J. Bruce Fields --- net/sunrpc/cache.c | 60 ++++++++++++++++++++++++++++-------------------------- 1 file changed, 31 insertions(+), 29 deletions(-) (limited to 'net/sunrpc') diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c index 673c2fa3c6c2..4a2340a54401 100644 --- a/net/sunrpc/cache.c +++ b/net/sunrpc/cache.c @@ -44,7 +44,7 @@ static void cache_revisit_request(struct cache_head *item); static void cache_init(struct cache_head *h) { time_t now = seconds_since_boot(); - h->next = NULL; + INIT_HLIST_NODE(&h->cache_list); h->flags = 0; kref_init(&h->ref); h->expiry_time = now + CACHE_NEW_EXPIRY; @@ -54,15 +54,14 @@ static void cache_init(struct cache_head *h) struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail, struct cache_head *key, int hash) { - struct cache_head **head, **hp; - struct cache_head *new = NULL, *freeme = NULL; + struct cache_head *new = NULL, *freeme = NULL, *tmp = NULL; + struct hlist_head *head; head = &detail->hash_table[hash]; read_lock(&detail->hash_lock); - for (hp=head; *hp != NULL ; hp = &(*hp)->next) { - struct cache_head *tmp = *hp; + hlist_for_each_entry(tmp, head, cache_list) { if (detail->match(tmp, key)) { if (cache_is_expired(detail, tmp)) /* This entry is expired, we will discard it. */ @@ -88,12 +87,10 @@ struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail, write_lock(&detail->hash_lock); /* check if entry appeared while we slept */ - for (hp=head; *hp != NULL ; hp = &(*hp)->next) { - struct cache_head *tmp = *hp; + hlist_for_each_entry(tmp, head, cache_list) { if (detail->match(tmp, key)) { if (cache_is_expired(detail, tmp)) { - *hp = tmp->next; - tmp->next = NULL; + hlist_del_init(&tmp->cache_list); detail->entries --; freeme = tmp; break; @@ -104,8 +101,8 @@ struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail, return tmp; } } - new->next = *head; - *head = new; + + hlist_add_head(&new->cache_list, head); detail->entries++; cache_get(new); write_unlock(&detail->hash_lock); @@ -143,7 +140,6 @@ struct cache_head *sunrpc_cache_update(struct cache_detail *detail, * If 'old' is not VALID, we update it directly, * otherwise we need to replace it */ - struct cache_head **head; struct cache_head *tmp; if (!test_bit(CACHE_VALID, &old->flags)) { @@ -168,15 +164,13 @@ struct cache_head *sunrpc_cache_update(struct cache_detail *detail, } cache_init(tmp); detail->init(tmp, old); - head = &detail->hash_table[hash]; write_lock(&detail->hash_lock); if (test_bit(CACHE_NEGATIVE, &new->flags)) set_bit(CACHE_NEGATIVE, &tmp->flags); else detail->update(tmp, new); - tmp->next = *head; - *head = tmp; + hlist_add_head(&tmp->cache_list, &detail->hash_table[hash]); detail->entries++; cache_get(tmp); cache_fresh_locked(tmp, new->expiry_time); @@ -416,28 +410,29 @@ static int cache_clean(void) /* find a non-empty bucket in the table */ while (current_detail && current_index < current_detail->hash_size && - current_detail->hash_table[current_index] == NULL) + hlist_empty(¤t_detail->hash_table[current_index])) current_index++; /* find a cleanable entry in the bucket and clean it, or set to next bucket */ if (current_detail && current_index < current_detail->hash_size) { - struct cache_head *ch, **cp; + struct cache_head *ch = NULL; struct cache_detail *d; + struct hlist_head *head; + struct hlist_node *tmp; write_lock(¤t_detail->hash_lock); /* Ok, now to clean this strand */ - cp = & current_detail->hash_table[current_index]; - for (ch = *cp ; ch ; cp = & ch->next, ch = *cp) { + head = ¤t_detail->hash_table[current_index]; + hlist_for_each_entry_safe(ch, tmp, head, cache_list) { if (current_detail->nextcheck > ch->expiry_time) current_detail->nextcheck = ch->expiry_time+1; if (!cache_is_expired(current_detail, ch)) continue; - *cp = ch->next; - ch->next = NULL; + hlist_del_init(&ch->cache_list); current_detail->entries--; rv = 1; break; @@ -1284,7 +1279,7 @@ void *cache_seq_start(struct seq_file *m, loff_t *pos) hash = n >> 32; entry = n & ((1LL<<32) - 1); - for (ch=cd->hash_table[hash]; ch; ch=ch->next) + hlist_for_each_entry(ch, &cd->hash_table[hash], cache_list) if (!entry--) return ch; n &= ~((1LL<<32) - 1); @@ -1292,11 +1287,12 @@ void *cache_seq_start(struct seq_file *m, loff_t *pos) hash++; n += 1LL<<32; } while(hash < cd->hash_size && - cd->hash_table[hash]==NULL); + hlist_empty(&cd->hash_table[hash])); if (hash >= cd->hash_size) return NULL; *pos = n+1; - return cd->hash_table[hash]; + return hlist_entry_safe(cd->hash_table[hash].first, + struct cache_head, cache_list); } EXPORT_SYMBOL_GPL(cache_seq_start); @@ -1308,23 +1304,25 @@ void *cache_seq_next(struct seq_file *m, void *p, loff_t *pos) if (p == SEQ_START_TOKEN) hash = 0; - else if (ch->next == NULL) { + else if (ch->cache_list.next == NULL) { hash++; *pos += 1LL<<32; } else { ++*pos; - return ch->next; + return hlist_entry_safe(ch->cache_list.next, + struct cache_head, cache_list); } *pos &= ~((1LL<<32) - 1); while (hash < cd->hash_size && - cd->hash_table[hash] == NULL) { + hlist_empty(&cd->hash_table[hash])) { hash++; *pos += 1LL<<32; } if (hash >= cd->hash_size) return NULL; ++*pos; - return cd->hash_table[hash]; + return hlist_entry_safe(cd->hash_table[hash].first, + struct cache_head, cache_list); } EXPORT_SYMBOL_GPL(cache_seq_next); @@ -1666,17 +1664,21 @@ EXPORT_SYMBOL_GPL(cache_unregister_net); struct cache_detail *cache_create_net(struct cache_detail *tmpl, struct net *net) { struct cache_detail *cd; + int i; cd = kmemdup(tmpl, sizeof(struct cache_detail), GFP_KERNEL); if (cd == NULL) return ERR_PTR(-ENOMEM); - cd->hash_table = kzalloc(cd->hash_size * sizeof(struct cache_head *), + cd->hash_table = kzalloc(cd->hash_size * sizeof(struct hlist_head), GFP_KERNEL); if (cd->hash_table == NULL) { kfree(cd); return ERR_PTR(-ENOMEM); } + + for (i = 0; i < cd->hash_size; i++) + INIT_HLIST_HEAD(&cd->hash_table[i]); cd->net = net; return cd; } -- cgit v1.2.3