summaryrefslogtreecommitdiff
path: root/net
diff options
context:
space:
mode:
Diffstat (limited to 'net')
-rw-r--r--net/sunrpc/cache.c98
1 files changed, 98 insertions, 0 deletions
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
index 0acccfeeb284..4449dc52edf5 100644
--- a/net/sunrpc/cache.c
+++ b/net/sunrpc/cache.c
@@ -47,6 +47,104 @@ void cache_init(struct cache_head *h)
h->last_refresh = now;
}
+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;
+
+ head = &detail->hash_table[hash];
+
+ read_lock(&detail->hash_lock);
+
+ for (hp=head; *hp != NULL ; hp = &(*hp)->next) {
+ struct cache_head *tmp = *hp;
+ if (detail->match(tmp, key)) {
+ cache_get(tmp);
+ read_unlock(&detail->hash_lock);
+ return tmp;
+ }
+ }
+ read_unlock(&detail->hash_lock);
+ /* Didn't find anything, insert an empty entry */
+
+ new = detail->alloc();
+ if (!new)
+ return NULL;
+ cache_init(new);
+
+ 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;
+ if (detail->match(tmp, key)) {
+ cache_get(tmp);
+ write_unlock(&detail->hash_lock);
+ detail->cache_put(new, detail);
+ return tmp;
+ }
+ }
+ detail->init(new, key);
+ new->next = *head;
+ *head = new;
+ detail->entries++;
+ cache_get(new);
+ write_unlock(&detail->hash_lock);
+
+ return new;
+}
+EXPORT_SYMBOL(sunrpc_cache_lookup);
+
+struct cache_head *sunrpc_cache_update(struct cache_detail *detail,
+ struct cache_head *new, struct cache_head *old, int hash)
+{
+ /* The 'old' entry is to be replaced by 'new'.
+ * 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)) {
+ write_lock(&detail->hash_lock);
+ if (!test_bit(CACHE_VALID, &old->flags)) {
+ if (test_bit(CACHE_NEGATIVE, &new->flags))
+ set_bit(CACHE_NEGATIVE, &old->flags);
+ else
+ detail->update(old, new);
+ /* FIXME cache_fresh should come first */
+ write_unlock(&detail->hash_lock);
+ cache_fresh(detail, old, new->expiry_time);
+ return old;
+ }
+ write_unlock(&detail->hash_lock);
+ }
+ /* We need to insert a new entry */
+ tmp = detail->alloc();
+ if (!tmp) {
+ detail->cache_put(old, detail);
+ return NULL;
+ }
+ 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;
+ cache_get(tmp);
+ write_unlock(&detail->hash_lock);
+ cache_fresh(detail, tmp, new->expiry_time);
+ cache_fresh(detail, old, 0);
+ detail->cache_put(old, detail);
+ return tmp;
+}
+EXPORT_SYMBOL(sunrpc_cache_update);
static int cache_make_upcall(struct cache_detail *detail, struct cache_head *h);
/*