SUNRPC: Give credential cache a local spinlock

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/include/linux/sunrpc/auth.h b/include/linux/sunrpc/auth.h
index 5974e8a..e5a3b51 100644 (file)
--- a/include/linux/sunrpc/auth.h
+++ b/include/linux/sunrpc/auth.h
@@ -63,6 +63,7 @@ struct rpc_cred {
 #define RPC_CREDCACHE_MASK     (RPC_CREDCACHE_NR - 1)
 struct rpc_cred_cache {
        struct hlist_head       hashtable[RPC_CREDCACHE_NR];
+       spinlock_t              lock;
        unsigned long           nextgc;         /* next garbage collection */
        unsigned long           expire;         /* cache expiry interval */
 };
@@ -126,6 +127,8 @@ struct rpc_credops {
 extern const struct rpc_authops        authunix_ops;
 extern const struct rpc_authops        authnull_ops;
 
+void __init            rpc_init_authunix(void);
+
 int                    rpcauth_register(const struct rpc_authops *);
 int                    rpcauth_unregister(const struct rpc_authops *);
 struct rpc_auth *      rpcauth_create(rpc_authflavor_t, struct rpc_clnt *);

diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c
index ad7bde2..cf1198d 100644 (file)
--- a/net/sunrpc/auth.c
+++ b/net/sunrpc/auth.c
@@ -120,6 +120,18 @@ rpcauth_unhash_cred_locked(struct rpc_cred *cred)
        clear_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
 }
 
+static void
+rpcauth_unhash_cred(struct rpc_cred *cred)
+{
+       spinlock_t *cache_lock;
+
+       cache_lock = &cred->cr_auth->au_credcache->lock;
+       spin_lock(cache_lock);
+       if (atomic_read(&cred->cr_count) == 0)
+               rpcauth_unhash_cred_locked(cred);
+       spin_unlock(cache_lock);
+}
+
 /*
  * Initialize RPC credential cache
  */
@@ -134,6 +146,7 @@ rpcauth_init_credcache(struct rpc_auth *auth, unsigned long expire)
                return -ENOMEM;
        for (i = 0; i < RPC_CREDCACHE_NR; i++)
                INIT_HLIST_HEAD(&new->hashtable[i]);
+       spin_lock_init(&new->lock);
        new->expire = expire;
        new->nextgc = jiffies + (expire >> 1);
        auth->au_credcache = new;
@@ -168,6 +181,7 @@ rpcauth_clear_credcache(struct rpc_cred_cache *cache)
        int             i;
 
        spin_lock(&rpc_credcache_lock);
+       spin_lock(&cache->lock);
        for (i = 0; i < RPC_CREDCACHE_NR; i++) {
                head = &cache->hashtable[i];
                while (!hlist_empty(head)) {
@@ -177,6 +191,7 @@ rpcauth_clear_credcache(struct rpc_cred_cache *cache)
                        rpcauth_unhash_cred_locked(cred);
                }
        }
+       spin_unlock(&cache->lock);
        spin_unlock(&rpc_credcache_lock);
        rpcauth_destroy_credlist(&free);
 }
@@ -202,6 +217,7 @@ rpcauth_destroy_credcache(struct rpc_auth *auth)
 static void
 rpcauth_prune_expired(struct list_head *free)
 {
+       spinlock_t *cache_lock;
        struct rpc_cred *cred;
 
        while (!list_empty(&cred_unused)) {
@@ -212,9 +228,14 @@ rpcauth_prune_expired(struct list_head *free)
                list_del_init(&cred->cr_lru);
                if (atomic_read(&cred->cr_count) != 0)
                        continue;
-               get_rpccred(cred);
-               list_add_tail(&cred->cr_lru, free);
-               rpcauth_unhash_cred_locked(cred);
+               cache_lock = &cred->cr_auth->au_credcache->lock;
+               spin_lock(cache_lock);
+               if (atomic_read(&cred->cr_count) == 0) {
+                       get_rpccred(cred);
+                       list_add_tail(&cred->cr_lru, free);
+                       rpcauth_unhash_cred_locked(cred);
+               }
+               spin_unlock(cache_lock);
        }
 }
 
@@ -253,21 +274,19 @@ rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
        hlist_for_each_entry_rcu(entry, pos, &cache->hashtable[nr], cr_hash) {
                if (!entry->cr_ops->crmatch(acred, entry, flags))
                        continue;
-               spin_lock(&rpc_credcache_lock);
+               spin_lock(&cache->lock);
                if (test_bit(RPCAUTH_CRED_HASHED, &entry->cr_flags) == 0) {
-                       spin_unlock(&rpc_credcache_lock);
+                       spin_unlock(&cache->lock);
                        continue;
                }
                cred = get_rpccred(entry);
-               spin_unlock(&rpc_credcache_lock);
+               spin_unlock(&cache->lock);
                break;
        }
        rcu_read_unlock();
 
-       if (cred != NULL) {
-               rpcauth_gc_credcache(cache, &free);
+       if (cred != NULL)
                goto found;
-       }
 
        new = auth->au_ops->crcreate(auth, acred, flags);
        if (IS_ERR(new)) {
@@ -275,7 +294,7 @@ rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
                goto out;
        }
 
-       spin_lock(&rpc_credcache_lock);
+       spin_lock(&cache->lock);
        hlist_for_each_entry(entry, pos, &cache->hashtable[nr], cr_hash) {
                if (!entry->cr_ops->crmatch(acred, entry, flags))
                        continue;
@@ -288,9 +307,7 @@ rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
                hlist_add_head_rcu(&cred->cr_hash, &cache->hashtable[nr]);
        } else
                list_add_tail(&new->cr_lru, &free);
-       rpcauth_prune_expired(&free);
-       cache->nextgc = jiffies + cache->expire;
-       spin_unlock(&rpc_credcache_lock);
+       spin_unlock(&cache->lock);
 found:
        if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags)
                        && cred->cr_ops->cr_init != NULL
@@ -301,6 +318,7 @@ found:
                        cred = ERR_PTR(res);
                }
        }
+       rpcauth_gc_credcache(cache, &free);
        rpcauth_destroy_credlist(&free);
 out:
        return cred;
@@ -393,7 +411,7 @@ need_lock:
        if (!list_empty(&cred->cr_lru))
                list_del_init(&cred->cr_lru);
        if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
-               rpcauth_unhash_cred_locked(cred);
+               rpcauth_unhash_cred(cred);
        else if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0) {
                cred->cr_expire = jiffies;
                list_add_tail(&cred->cr_lru, &cred_unused);

diff --git a/net/sunrpc/auth_unix.c b/net/sunrpc/auth_unix.c
index f7ff6ad..205878a 100644 (file)
--- a/net/sunrpc/auth_unix.c
+++ b/net/sunrpc/auth_unix.c
@@ -213,6 +213,11 @@ unx_validate(struct rpc_task *task, __be32 *p)
        return p;
 }
 
+void __init rpc_init_authunix(void)
+{
+       spin_lock_init(&unix_cred_cache.lock);
+}
+
 const struct rpc_authops authunix_ops = {
        .owner          = THIS_MODULE,
        .au_flavor      = RPC_AUTH_UNIX,

diff --git a/net/sunrpc/sunrpc_syms.c b/net/sunrpc/sunrpc_syms.c
index 3e19e7a..018065f 100644 (file)
--- a/net/sunrpc/sunrpc_syms.c
+++ b/net/sunrpc/sunrpc_syms.c
@@ -152,6 +152,7 @@ init_sunrpc(void)
        cache_register(&ip_map_cache);
        cache_register(&unix_gid_cache);
        init_socket_xprt();
+       rpc_init_authunix();
 out:
        return err;
 }