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-rw-r--r--include/linux/sunrpc/cache.h12
-rw-r--r--net/sunrpc/cache.c93
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);
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-06 19:11:58 +0000