diff options
| -rw-r--r-- | include/linux/sunrpc/cache.h | 12 | ||||
| -rw-r--r-- | net/sunrpc/cache.c | 93 |
2 files changed, 91 insertions, 14 deletions
diff --git a/include/linux/sunrpc/cache.h b/include/linux/sunrpc/cache.h index 40d2822f0e2f..cf3e17ee2786 100644 --- a/include/linux/sunrpc/cache.h +++ b/include/linux/sunrpc/cache.h @@ -168,6 +168,9 @@ extern const struct file_operations content_file_operations_pipefs; extern const struct file_operations cache_flush_operations_pipefs; extern struct cache_head * +sunrpc_cache_lookup_rcu(struct cache_detail *detail, + struct cache_head *key, int hash); +extern struct cache_head * sunrpc_cache_lookup(struct cache_detail *detail, struct cache_head *key, int hash); extern struct cache_head * @@ -186,6 +189,12 @@ static inline struct cache_head *cache_get(struct cache_head *h) return h; } +static inline struct cache_head *cache_get_rcu(struct cache_head *h) +{ + if (kref_get_unless_zero(&h->ref)) + return h; + return NULL; +} static inline void cache_put(struct cache_head *h, struct cache_detail *cd) { @@ -227,6 +236,9 @@ extern void sunrpc_cache_unhash(struct cache_detail *, struct cache_head *); extern void *cache_seq_start(struct seq_file *file, loff_t *pos); extern void *cache_seq_next(struct seq_file *file, void *p, loff_t *pos); extern void cache_seq_stop(struct seq_file *file, void *p); +extern void *cache_seq_start_rcu(struct seq_file *file, loff_t *pos); +extern void *cache_seq_next_rcu(struct seq_file *file, void *p, loff_t *pos); +extern void cache_seq_stop_rcu(struct seq_file *file, void *p); extern void qword_add(char **bpp, int *lp, char *str); extern void qword_addhex(char **bpp, int *lp, char *buf, int blen); diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c index aa8e62d61f4d..7593afed9036 100644 --- a/net/sunrpc/cache.c +++ b/net/sunrpc/cache.c @@ -54,6 +54,27 @@ static void cache_init(struct cache_head *h, struct cache_detail *detail) h->last_refresh = now; } +static struct cache_head *sunrpc_cache_find_rcu(struct cache_detail *detail, + struct cache_head *key, + int hash) +{ + struct hlist_head *head = &detail->hash_table[hash]; + struct cache_head *tmp; + + rcu_read_lock(); + hlist_for_each_entry_rcu(tmp, head, cache_list) { + if (detail->match(tmp, key)) { + if (cache_is_expired(detail, tmp)) + continue; + tmp = cache_get_rcu(tmp); + rcu_read_unlock(); + return tmp; + } + } + rcu_read_unlock(); + return NULL; +} + static struct cache_head *sunrpc_cache_find(struct cache_detail *detail, struct cache_head *key, int hash) { @@ -61,7 +82,6 @@ static struct cache_head *sunrpc_cache_find(struct cache_detail *detail, struct cache_head *tmp; read_lock(&detail->hash_lock); - hlist_for_each_entry(tmp, head, cache_list) { if (detail->match(tmp, key)) { if (cache_is_expired(detail, tmp)) @@ -96,10 +116,10 @@ static struct cache_head *sunrpc_cache_add_entry(struct cache_detail *detail, write_lock(&detail->hash_lock); /* check if entry appeared while we slept */ - hlist_for_each_entry(tmp, head, cache_list) { + hlist_for_each_entry_rcu(tmp, head, cache_list) { if (detail->match(tmp, key)) { if (cache_is_expired(detail, tmp)) { - hlist_del_init(&tmp->cache_list); + hlist_del_init_rcu(&tmp->cache_list); detail->entries --; freeme = tmp; break; @@ -111,7 +131,7 @@ static struct cache_head *sunrpc_cache_add_entry(struct cache_detail *detail, } } - hlist_add_head(&new->cache_list, head); + hlist_add_head_rcu(&new->cache_list, head); detail->entries++; cache_get(new); write_unlock(&detail->hash_lock); @@ -121,6 +141,19 @@ static struct cache_head *sunrpc_cache_add_entry(struct cache_detail *detail, return new; } +struct cache_head *sunrpc_cache_lookup_rcu(struct cache_detail *detail, + struct cache_head *key, int hash) +{ + struct cache_head *ret; + + ret = sunrpc_cache_find_rcu(detail, key, hash); + if (ret) + return ret; + /* Didn't find anything, insert an empty entry */ + return sunrpc_cache_add_entry(detail, key, hash); +} +EXPORT_SYMBOL_GPL(sunrpc_cache_lookup_rcu); + struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail, struct cache_head *key, int hash) { @@ -134,6 +167,7 @@ struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail, } EXPORT_SYMBOL_GPL(sunrpc_cache_lookup); + static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch); static void cache_fresh_locked(struct cache_head *head, time_t expiry, @@ -450,7 +484,7 @@ static int cache_clean(void) if (!cache_is_expired(current_detail, ch)) continue; - hlist_del_init(&ch->cache_list); + hlist_del_init_rcu(&ch->cache_list); current_detail->entries--; rv = 1; break; @@ -521,7 +555,7 @@ void cache_purge(struct cache_detail *detail) for (i = 0; i < detail->hash_size; i++) { head = &detail->hash_table[i]; hlist_for_each_entry_safe(ch, tmp, head, cache_list) { - hlist_del_init(&ch->cache_list); + hlist_del_init_rcu(&ch->cache_list); detail->entries--; set_bit(CACHE_CLEANED, &ch->flags); @@ -1306,21 +1340,19 @@ EXPORT_SYMBOL_GPL(qword_get); * get a header, then pass each real item in the cache */ -void *cache_seq_start(struct seq_file *m, loff_t *pos) - __acquires(cd->hash_lock) +static void *__cache_seq_start(struct seq_file *m, loff_t *pos) { loff_t n = *pos; unsigned int hash, entry; struct cache_head *ch; struct cache_detail *cd = m->private; - read_lock(&cd->hash_lock); if (!n--) return SEQ_START_TOKEN; hash = n >> 32; entry = n & ((1LL<<32) - 1); - hlist_for_each_entry(ch, &cd->hash_table[hash], cache_list) + hlist_for_each_entry_rcu(ch, &cd->hash_table[hash], cache_list) if (!entry--) return ch; n &= ~((1LL<<32) - 1); @@ -1332,9 +1364,19 @@ void *cache_seq_start(struct seq_file *m, loff_t *pos) if (hash >= cd->hash_size) return NULL; *pos = n+1; - return hlist_entry_safe(cd->hash_table[hash].first, + return hlist_entry_safe(rcu_dereference_raw( + hlist_first_rcu(&cd->hash_table[hash])), struct cache_head, cache_list); } + +void *cache_seq_start(struct seq_file *m, loff_t *pos) + __acquires(cd->hash_lock) +{ + struct cache_detail *cd = m->private; + + read_lock(&cd->hash_lock); + return __cache_seq_start(m, pos); +} EXPORT_SYMBOL_GPL(cache_seq_start); void *cache_seq_next(struct seq_file *m, void *p, loff_t *pos) @@ -1350,7 +1392,8 @@ void *cache_seq_next(struct seq_file *m, void *p, loff_t *pos) *pos += 1LL<<32; } else { ++*pos; - return hlist_entry_safe(ch->cache_list.next, + return hlist_entry_safe(rcu_dereference_raw( + hlist_next_rcu(&ch->cache_list)), struct cache_head, cache_list); } *pos &= ~((1LL<<32) - 1); @@ -1362,7 +1405,8 @@ void *cache_seq_next(struct seq_file *m, void *p, loff_t *pos) if (hash >= cd->hash_size) return NULL; ++*pos; - return hlist_entry_safe(cd->hash_table[hash].first, + return hlist_entry_safe(rcu_dereference_raw( + hlist_first_rcu(&cd->hash_table[hash])), struct cache_head, cache_list); } EXPORT_SYMBOL_GPL(cache_seq_next); @@ -1375,6 +1419,27 @@ void cache_seq_stop(struct seq_file *m, void *p) } EXPORT_SYMBOL_GPL(cache_seq_stop); +void *cache_seq_start_rcu(struct seq_file *m, loff_t *pos) + __acquires(RCU) +{ + rcu_read_lock(); + return __cache_seq_start(m, pos); +} +EXPORT_SYMBOL_GPL(cache_seq_start_rcu); + +void *cache_seq_next_rcu(struct seq_file *file, void *p, loff_t *pos) +{ + return cache_seq_next(file, p, pos); +} +EXPORT_SYMBOL_GPL(cache_seq_next_rcu); + +void cache_seq_stop_rcu(struct seq_file *m, void *p) + __releases(RCU) +{ + rcu_read_unlock(); +} +EXPORT_SYMBOL_GPL(cache_seq_stop_rcu); + static int c_show(struct seq_file *m, void *p) { struct cache_head *cp = p; @@ -1863,7 +1928,7 @@ void sunrpc_cache_unhash(struct cache_detail *cd, struct cache_head *h) { write_lock(&cd->hash_lock); if (!hlist_unhashed(&h->cache_list)){ - hlist_del_init(&h->cache_list); + hlist_del_init_rcu(&h->cache_list); cd->entries--; write_unlock(&cd->hash_lock); cache_put(h, cd); |