Return-Path: Received: from mail-pa0-f52.google.com ([209.85.220.52]:34220 "EHLO mail-pa0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752187AbbFYOaB (ORCPT ); Thu, 25 Jun 2015 10:30:01 -0400 Message-ID: <558C105E.4000707@gmail.com> Date: Thu, 25 Jun 2015 22:29:50 +0800 From: Kinglong Mee MIME-Version: 1.0 To: Al Viro , "J. Bruce Fields" , "linux-nfs@vger.kernel.org" , linux-fsdevel@vger.kernel.org CC: NeilBrown , Trond Myklebust , kinglongmee@gmail.com Subject: [PATCH 07/10 v6] sunrpc: Switch to using list_head instead single list References: <558C0D6A.9050104@gmail.com> In-Reply-To: <558C0D6A.9050104@gmail.com> Content-Type: text/plain; charset=utf-8 Sender: linux-nfs-owner@vger.kernel.org List-ID: Switch using list_head for cache_head in cache_detail, it is useful of remove an cache_head entry directly from cache_detail. Signed-off-by: Kinglong Mee --- include/linux/sunrpc/cache.h | 4 +-- net/sunrpc/cache.c | 74 ++++++++++++++++++++++++-------------------- 2 files changed, 43 insertions(+), 35 deletions(-) diff --git a/include/linux/sunrpc/cache.h b/include/linux/sunrpc/cache.h index 04ee5a2..ecc0ff6 100644 --- a/include/linux/sunrpc/cache.h +++ b/include/linux/sunrpc/cache.h @@ -46,7 +46,7 @@ * */ struct cache_head { - struct cache_head * next; + struct list_head cache_list; time_t expiry_time; /* After time time, don't use the data */ time_t last_refresh; /* If CACHE_PENDING, this is when upcall * was sent, else this is when update was received @@ -73,7 +73,7 @@ struct cache_detail_pipefs { struct cache_detail { struct module * owner; int hash_size; - struct cache_head ** hash_table; + struct list_head * hash_table; rwlock_t hash_lock; atomic_t inuse; /* active user-space update or lookup */ diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c index 673c2fa..ad2155c 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_LIST_HEAD(&h->cache_list); h->flags = 0; kref_init(&h->ref); h->expiry_time = now + CACHE_NEW_EXPIRY; @@ -54,15 +54,16 @@ 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 *tmp; + struct list_head *head, *pos, *tpos; head = &detail->hash_table[hash]; read_lock(&detail->hash_lock); - for (hp=head; *hp != NULL ; hp = &(*hp)->next) { - struct cache_head *tmp = *hp; + list_for_each_safe(pos, tpos, head) { + tmp = list_entry(pos, struct cache_head, cache_list); if (detail->match(tmp, key)) { if (cache_is_expired(detail, tmp)) /* This entry is expired, we will discard it. */ @@ -88,12 +89,11 @@ 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; + list_for_each_safe(pos, tpos, head) { + tmp = list_entry(pos, struct cache_head, cache_list); if (detail->match(tmp, key)) { if (cache_is_expired(detail, tmp)) { - *hp = tmp->next; - tmp->next = NULL; + list_del_init(&tmp->cache_list); detail->entries --; freeme = tmp; break; @@ -104,8 +104,8 @@ struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail, return tmp; } } - new->next = *head; - *head = new; + + list_add(&new->cache_list, head); detail->entries++; cache_get(new); write_unlock(&detail->hash_lock); @@ -143,7 +143,6 @@ 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 +167,13 @@ 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; + list_add(&tmp->cache_list, &detail->hash_table[hash]); detail->entries++; cache_get(tmp); cache_fresh_locked(tmp, new->expiry_time); @@ -416,42 +413,44 @@ 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) + list_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, *putme = NULL; + struct list_head *head, *pos, *tpos; struct cache_detail *d; 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]; + list_for_each_safe(pos, tpos, head) { + ch = list_entry(pos, struct cache_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; + list_del_init(pos); current_detail->entries--; + putme = ch; rv = 1; break; } write_unlock(¤t_detail->hash_lock); d = current_detail; - if (!ch) + if (!putme) current_index ++; spin_unlock(&cache_list_lock); - if (ch) { - set_bit(CACHE_CLEANED, &ch->flags); - cache_fresh_unlocked(ch, d); - cache_put(ch, d); + if (putme) { + set_bit(CACHE_CLEANED, &putme->flags); + cache_fresh_unlocked(putme, d); + cache_put(putme, d); } } else spin_unlock(&cache_list_lock); @@ -1277,6 +1276,7 @@ void *cache_seq_start(struct seq_file *m, loff_t *pos) unsigned int hash, entry; struct cache_head *ch; struct cache_detail *cd = m->private; + struct list_head *ptr, *tptr; read_lock(&cd->hash_lock); if (!n--) @@ -1284,19 +1284,22 @@ 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) + list_for_each_safe(ptr, tptr, &cd->hash_table[hash]) { + ch = list_entry(ptr, struct cache_head, cache_list); if (!entry--) return ch; + } n &= ~((1LL<<32) - 1); do { hash++; n += 1LL<<32; } while(hash < cd->hash_size && - cd->hash_table[hash]==NULL); + list_empty(&cd->hash_table[hash])); if (hash >= cd->hash_size) return NULL; *pos = n+1; - return cd->hash_table[hash]; + return list_first_entry_or_null(&cd->hash_table[hash], + struct cache_head, cache_list); } EXPORT_SYMBOL_GPL(cache_seq_start); @@ -1308,23 +1311,24 @@ 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 (list_is_last(&ch->cache_list, &cd->hash_table[hash])) { hash++; *pos += 1LL<<32; } else { ++*pos; - return ch->next; + return list_next_entry(ch, cache_list); } *pos &= ~((1LL<<32) - 1); while (hash < cd->hash_size && - cd->hash_table[hash] == NULL) { + list_empty(&cd->hash_table[hash])) { hash++; *pos += 1LL<<32; } if (hash >= cd->hash_size) return NULL; ++*pos; - return cd->hash_table[hash]; + return list_first_entry_or_null(&cd->hash_table[hash], + struct cache_head, cache_list); } EXPORT_SYMBOL_GPL(cache_seq_next); @@ -1666,17 +1670,21 @@ 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 list_head), GFP_KERNEL); if (cd->hash_table == NULL) { kfree(cd); return ERR_PTR(-ENOMEM); } + + for (i = 0; i < cd->hash_size; i++) + INIT_LIST_HEAD(&cd->hash_table[i]); cd->net = net; return cd; } -- 2.4.3