Fedora kernel-2.6.17-1.2142_FC4 patched with stable patch-2.6.17.4-vs2.0.2-rc26.diff

[linux-2.6.git] / net / sunrpc / svcauth.c

diff --git a/net/sunrpc/svcauth.c b/net/sunrpc/svcauth.c
index bde8147..5b28c61 100644 (file)
--- a/net/sunrpc/svcauth.c
+++ b/net/sunrpc/svcauth.c
@@ -106,111 +106,56 @@ svc_auth_unregister(rpc_authflavor_t flavor)
 EXPORT_SYMBOL(svc_auth_unregister);
 
 /**************************************************
- * cache for domain name to auth_domain
- * Entries are only added by flavours which will normally
- * have a structure that 'inherits' from auth_domain.
- * e.g. when an IP -> domainname is given to  auth_unix,
- * and the domain name doesn't exist, it will create a
- * auth_unix_domain and add it to this hash table.
- * If it finds the name does exist, but isn't AUTH_UNIX,
- * it will complain.
+ * 'auth_domains' are stored in a hash table indexed by name.
+ * When the last reference to an 'auth_domain' is dropped,
+ * the object is unhashed and freed.
+ * If auth_domain_lookup fails to find an entry, it will return
+ * it's second argument 'new'.  If this is non-null, it will
+ * have been atomically linked into the table.
  */
 
-/*
- * Auth auth_domain cache is somewhat different to other caches,
- * largely because the entries are possibly of different types:
- * each auth flavour has it's own type.
- * One consequence of this that DefineCacheLookup cannot
- * allocate a new structure as it cannot know the size.
- * Notice that the "INIT" code fragment is quite different
- * from other caches.  When auth_domain_lookup might be
- * creating a new domain, the new domain is passed in
- * complete and it is used as-is rather than being copied into
- * another structure.
- */
 #define        DN_HASHBITS     6
 #define        DN_HASHMAX      (1<<DN_HASHBITS)
 #define        DN_HASHMASK     (DN_HASHMAX-1)
 
-static struct cache_head       *auth_domain_table[DN_HASHMAX];
-
-static void auth_domain_drop(struct cache_head *item, struct cache_detail *cd)
-{
-       struct auth_domain *dom = container_of(item, struct auth_domain, h);
-       if (cache_put(item,cd))
-               authtab[dom->flavour]->domain_release(dom);
-}
-
-
-struct cache_detail auth_domain_cache = {
-       .hash_size      = DN_HASHMAX,
-       .hash_table     = auth_domain_table,
-       .name           = "auth.domain",
-       .cache_put      = auth_domain_drop,
-};
+static struct hlist_head       auth_domain_table[DN_HASHMAX];
+static spinlock_t      auth_domain_lock = SPIN_LOCK_UNLOCKED;
 
 void auth_domain_put(struct auth_domain *dom)
 {
-       auth_domain_drop(&dom->h, &auth_domain_cache);
-}
-
-static inline int auth_domain_hash(struct auth_domain *item)
-{
-       return hash_str(item->name, DN_HASHBITS);
-}
-static inline int auth_domain_match(struct auth_domain *tmp, struct auth_domain *item)
-{
-       return strcmp(tmp->name, item->name) == 0;
+       if (atomic_dec_and_lock(&dom->ref.refcount, &auth_domain_lock)) {
+               hlist_del(&dom->hash);
+               dom->flavour->domain_release(dom);
+       }
 }
 
 struct auth_domain *
-auth_domain_lookup(struct auth_domain *item, int set)
+auth_domain_lookup(char *name, struct auth_domain *new)
 {
-       struct auth_domain *tmp = NULL;
-       struct cache_head **hp, **head;
-       head = &auth_domain_cache.hash_table[auth_domain_hash(item)];
-
-       if (set)
-               write_lock(&auth_domain_cache.hash_lock);
-       else
-               read_lock(&auth_domain_cache.hash_lock);
-       for (hp=head; *hp != NULL; hp = &tmp->h.next) {
-               tmp = container_of(*hp, struct auth_domain, h);
-               if (!auth_domain_match(tmp, item))
-                       continue;
-               if (!set) {
-                       cache_get(&tmp->h);
-                       goto out_noset;
+       struct auth_domain *hp;
+       struct hlist_head *head;
+       struct hlist_node *np;
+
+       head = &auth_domain_table[hash_str(name, DN_HASHBITS)];
+
+       spin_lock(&auth_domain_lock);
+
+       hlist_for_each_entry(hp, np, head, hash) {
+               if (strcmp(hp->name, name)==0) {
+                       kref_get(&hp->ref);
+                       spin_unlock(&auth_domain_lock);
+                       return hp;
                }
-               *hp = tmp->h.next;
-               tmp->h.next = NULL;
-               auth_domain_drop(&tmp->h, &auth_domain_cache);
-               goto out_set;
        }
-       /* Didn't find anything */
-       if (!set)
-               goto out_nada;
-       auth_domain_cache.entries++;
-out_set:
-       item->h.next = *head;
-       *head = &item->h;
-       cache_get(&item->h);
-       write_unlock(&auth_domain_cache.hash_lock);
-       cache_fresh(&auth_domain_cache, &item->h, item->h.expiry_time);
-       cache_get(&item->h);
-       return item;
-out_nada:
-       tmp = NULL;
-out_noset:
-       read_unlock(&auth_domain_cache.hash_lock);
-       return tmp;
+       if (new) {
+               hlist_add_head(&new->hash, head);
+               kref_get(&new->ref);
+       }
+       spin_unlock(&auth_domain_lock);
+       return new;
 }
 
 struct auth_domain *auth_domain_find(char *name)
 {
-       struct auth_domain *rv, ad;
-
-       ad.name = name;
-       rv = auth_domain_lookup(&ad, 0);
-       return rv;
+       return auth_domain_lookup(name, NULL);
 }