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Diffstat (limited to 'net/sunrpc/auth.c')
-rw-r--r--net/sunrpc/auth.c310
1 files changed, 169 insertions, 141 deletions
diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c
index 305ecea92170..ad8ead738981 100644
--- a/net/sunrpc/auth.c
+++ b/net/sunrpc/auth.c
@@ -30,10 +30,9 @@ struct rpc_cred_cache {
static unsigned int auth_hashbits = RPC_CREDCACHE_DEFAULT_HASHBITS;
-static DEFINE_SPINLOCK(rpc_authflavor_lock);
-static const struct rpc_authops *auth_flavors[RPC_AUTH_MAXFLAVOR] = {
- &authnull_ops, /* AUTH_NULL */
- &authunix_ops, /* AUTH_UNIX */
+static const struct rpc_authops __rcu *auth_flavors[RPC_AUTH_MAXFLAVOR] = {
+ [RPC_AUTH_NULL] = (const struct rpc_authops __force __rcu *)&authnull_ops,
+ [RPC_AUTH_UNIX] = (const struct rpc_authops __force __rcu *)&authunix_ops,
NULL, /* others can be loadable modules */
};
@@ -93,39 +92,65 @@ pseudoflavor_to_flavor(u32 flavor) {
int
rpcauth_register(const struct rpc_authops *ops)
{
+ const struct rpc_authops *old;
rpc_authflavor_t flavor;
- int ret = -EPERM;
if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
return -EINVAL;
- spin_lock(&rpc_authflavor_lock);
- if (auth_flavors[flavor] == NULL) {
- auth_flavors[flavor] = ops;
- ret = 0;
- }
- spin_unlock(&rpc_authflavor_lock);
- return ret;
+ old = cmpxchg((const struct rpc_authops ** __force)&auth_flavors[flavor], NULL, ops);
+ if (old == NULL || old == ops)
+ return 0;
+ return -EPERM;
}
EXPORT_SYMBOL_GPL(rpcauth_register);
int
rpcauth_unregister(const struct rpc_authops *ops)
{
+ const struct rpc_authops *old;
rpc_authflavor_t flavor;
- int ret = -EPERM;
if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
return -EINVAL;
- spin_lock(&rpc_authflavor_lock);
- if (auth_flavors[flavor] == ops) {
- auth_flavors[flavor] = NULL;
- ret = 0;
- }
- spin_unlock(&rpc_authflavor_lock);
- return ret;
+
+ old = cmpxchg((const struct rpc_authops ** __force)&auth_flavors[flavor], ops, NULL);
+ if (old == ops || old == NULL)
+ return 0;
+ return -EPERM;
}
EXPORT_SYMBOL_GPL(rpcauth_unregister);
+static const struct rpc_authops *
+rpcauth_get_authops(rpc_authflavor_t flavor)
+{
+ const struct rpc_authops *ops;
+
+ if (flavor >= RPC_AUTH_MAXFLAVOR)
+ return NULL;
+
+ rcu_read_lock();
+ ops = rcu_dereference(auth_flavors[flavor]);
+ if (ops == NULL) {
+ rcu_read_unlock();
+ request_module("rpc-auth-%u", flavor);
+ rcu_read_lock();
+ ops = rcu_dereference(auth_flavors[flavor]);
+ if (ops == NULL)
+ goto out;
+ }
+ if (!try_module_get(ops->owner))
+ ops = NULL;
+out:
+ rcu_read_unlock();
+ return ops;
+}
+
+static void
+rpcauth_put_authops(const struct rpc_authops *ops)
+{
+ module_put(ops->owner);
+}
+
/**
* rpcauth_get_pseudoflavor - check if security flavor is supported
* @flavor: a security flavor
@@ -138,25 +163,16 @@ EXPORT_SYMBOL_GPL(rpcauth_unregister);
rpc_authflavor_t
rpcauth_get_pseudoflavor(rpc_authflavor_t flavor, struct rpcsec_gss_info *info)
{
- const struct rpc_authops *ops;
+ const struct rpc_authops *ops = rpcauth_get_authops(flavor);
rpc_authflavor_t pseudoflavor;
- ops = auth_flavors[flavor];
- if (ops == NULL)
- request_module("rpc-auth-%u", flavor);
- spin_lock(&rpc_authflavor_lock);
- ops = auth_flavors[flavor];
- if (ops == NULL || !try_module_get(ops->owner)) {
- spin_unlock(&rpc_authflavor_lock);
+ if (!ops)
return RPC_AUTH_MAXFLAVOR;
- }
- spin_unlock(&rpc_authflavor_lock);
-
pseudoflavor = flavor;
if (ops->info2flavor != NULL)
pseudoflavor = ops->info2flavor(info);
- module_put(ops->owner);
+ rpcauth_put_authops(ops);
return pseudoflavor;
}
EXPORT_SYMBOL_GPL(rpcauth_get_pseudoflavor);
@@ -176,25 +192,15 @@ rpcauth_get_gssinfo(rpc_authflavor_t pseudoflavor, struct rpcsec_gss_info *info)
const struct rpc_authops *ops;
int result;
- if (flavor >= RPC_AUTH_MAXFLAVOR)
- return -EINVAL;
-
- ops = auth_flavors[flavor];
+ ops = rpcauth_get_authops(flavor);
if (ops == NULL)
- request_module("rpc-auth-%u", flavor);
- spin_lock(&rpc_authflavor_lock);
- ops = auth_flavors[flavor];
- if (ops == NULL || !try_module_get(ops->owner)) {
- spin_unlock(&rpc_authflavor_lock);
return -ENOENT;
- }
- spin_unlock(&rpc_authflavor_lock);
result = -ENOENT;
if (ops->flavor2info != NULL)
result = ops->flavor2info(pseudoflavor, info);
- module_put(ops->owner);
+ rpcauth_put_authops(ops);
return result;
}
EXPORT_SYMBOL_GPL(rpcauth_get_gssinfo);
@@ -212,15 +218,13 @@ EXPORT_SYMBOL_GPL(rpcauth_get_gssinfo);
int
rpcauth_list_flavors(rpc_authflavor_t *array, int size)
{
- rpc_authflavor_t flavor;
- int result = 0;
+ const struct rpc_authops *ops;
+ rpc_authflavor_t flavor, pseudos[4];
+ int i, len, result = 0;
- spin_lock(&rpc_authflavor_lock);
+ rcu_read_lock();
for (flavor = 0; flavor < RPC_AUTH_MAXFLAVOR; flavor++) {
- const struct rpc_authops *ops = auth_flavors[flavor];
- rpc_authflavor_t pseudos[4];
- int i, len;
-
+ ops = rcu_dereference(auth_flavors[flavor]);
if (result >= size) {
result = -ENOMEM;
break;
@@ -245,7 +249,7 @@ rpcauth_list_flavors(rpc_authflavor_t *array, int size)
array[result++] = pseudos[i];
}
}
- spin_unlock(&rpc_authflavor_lock);
+ rcu_read_unlock();
dprintk("RPC: %s returns %d\n", __func__, result);
return result;
@@ -255,25 +259,17 @@ EXPORT_SYMBOL_GPL(rpcauth_list_flavors);
struct rpc_auth *
rpcauth_create(const struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
{
- struct rpc_auth *auth;
+ struct rpc_auth *auth = ERR_PTR(-EINVAL);
const struct rpc_authops *ops;
- u32 flavor = pseudoflavor_to_flavor(args->pseudoflavor);
+ u32 flavor = pseudoflavor_to_flavor(args->pseudoflavor);
- auth = ERR_PTR(-EINVAL);
- if (flavor >= RPC_AUTH_MAXFLAVOR)
+ ops = rpcauth_get_authops(flavor);
+ if (ops == NULL)
goto out;
- if ((ops = auth_flavors[flavor]) == NULL)
- request_module("rpc-auth-%u", flavor);
- spin_lock(&rpc_authflavor_lock);
- ops = auth_flavors[flavor];
- if (ops == NULL || !try_module_get(ops->owner)) {
- spin_unlock(&rpc_authflavor_lock);
- goto out;
- }
- spin_unlock(&rpc_authflavor_lock);
auth = ops->create(args, clnt);
- module_put(ops->owner);
+
+ rpcauth_put_authops(ops);
if (IS_ERR(auth))
return auth;
if (clnt->cl_auth)
@@ -288,32 +284,37 @@ EXPORT_SYMBOL_GPL(rpcauth_create);
void
rpcauth_release(struct rpc_auth *auth)
{
- if (!atomic_dec_and_test(&auth->au_count))
+ if (!refcount_dec_and_test(&auth->au_count))
return;
auth->au_ops->destroy(auth);
}
static DEFINE_SPINLOCK(rpc_credcache_lock);
-static void
+/*
+ * On success, the caller is responsible for freeing the reference
+ * held by the hashtable
+ */
+static bool
rpcauth_unhash_cred_locked(struct rpc_cred *cred)
{
+ if (!test_and_clear_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags))
+ return false;
hlist_del_rcu(&cred->cr_hash);
- smp_mb__before_atomic();
- clear_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
+ return true;
}
-static int
+static bool
rpcauth_unhash_cred(struct rpc_cred *cred)
{
spinlock_t *cache_lock;
- int ret;
+ bool ret;
+ if (!test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags))
+ return false;
cache_lock = &cred->cr_auth->au_credcache->lock;
spin_lock(cache_lock);
- ret = atomic_read(&cred->cr_count) == 0;
- if (ret)
- rpcauth_unhash_cred_locked(cred);
+ ret = rpcauth_unhash_cred_locked(cred);
spin_unlock(cache_lock);
return ret;
}
@@ -392,6 +393,44 @@ void rpcauth_destroy_credlist(struct list_head *head)
}
}
+static void
+rpcauth_lru_add_locked(struct rpc_cred *cred)
+{
+ if (!list_empty(&cred->cr_lru))
+ return;
+ number_cred_unused++;
+ list_add_tail(&cred->cr_lru, &cred_unused);
+}
+
+static void
+rpcauth_lru_add(struct rpc_cred *cred)
+{
+ if (!list_empty(&cred->cr_lru))
+ return;
+ spin_lock(&rpc_credcache_lock);
+ rpcauth_lru_add_locked(cred);
+ spin_unlock(&rpc_credcache_lock);
+}
+
+static void
+rpcauth_lru_remove_locked(struct rpc_cred *cred)
+{
+ if (list_empty(&cred->cr_lru))
+ return;
+ number_cred_unused--;
+ list_del_init(&cred->cr_lru);
+}
+
+static void
+rpcauth_lru_remove(struct rpc_cred *cred)
+{
+ if (list_empty(&cred->cr_lru))
+ return;
+ spin_lock(&rpc_credcache_lock);
+ rpcauth_lru_remove_locked(cred);
+ spin_unlock(&rpc_credcache_lock);
+}
+
/*
* Clear the RPC credential cache, and delete those credentials
* that are not referenced.
@@ -411,13 +450,10 @@ rpcauth_clear_credcache(struct rpc_cred_cache *cache)
head = &cache->hashtable[i];
while (!hlist_empty(head)) {
cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
- get_rpccred(cred);
- if (!list_empty(&cred->cr_lru)) {
- list_del(&cred->cr_lru);
- number_cred_unused--;
- }
- list_add_tail(&cred->cr_lru, &free);
rpcauth_unhash_cred_locked(cred);
+ /* Note: We now hold a reference to cred */
+ rpcauth_lru_remove_locked(cred);
+ list_add_tail(&cred->cr_lru, &free);
}
}
spin_unlock(&cache->lock);
@@ -451,7 +487,6 @@ EXPORT_SYMBOL_GPL(rpcauth_destroy_credcache);
static long
rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
{
- spinlock_t *cache_lock;
struct rpc_cred *cred, *next;
unsigned long expired = jiffies - RPC_AUTH_EXPIRY_MORATORIUM;
long freed = 0;
@@ -460,32 +495,24 @@ rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
if (nr_to_scan-- == 0)
break;
+ if (refcount_read(&cred->cr_count) > 1) {
+ rpcauth_lru_remove_locked(cred);
+ continue;
+ }
/*
* Enforce a 60 second garbage collection moratorium
* Note that the cred_unused list must be time-ordered.
*/
- if (time_in_range(cred->cr_expire, expired, jiffies) &&
- test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0) {
- freed = SHRINK_STOP;
- break;
- }
-
- list_del_init(&cred->cr_lru);
- number_cred_unused--;
- freed++;
- if (atomic_read(&cred->cr_count) != 0)
+ if (!time_in_range(cred->cr_expire, expired, jiffies))
+ continue;
+ if (!rpcauth_unhash_cred(cred))
continue;
- 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);
+ rpcauth_lru_remove_locked(cred);
+ freed++;
+ list_add_tail(&cred->cr_lru, free);
}
- return freed;
+ return freed ? freed : SHRINK_STOP;
}
static unsigned long
@@ -561,19 +588,15 @@ rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
if (!entry->cr_ops->crmatch(acred, entry, flags))
continue;
if (flags & RPCAUTH_LOOKUP_RCU) {
- if (test_bit(RPCAUTH_CRED_HASHED, &entry->cr_flags) &&
- !test_bit(RPCAUTH_CRED_NEW, &entry->cr_flags))
- cred = entry;
+ if (test_bit(RPCAUTH_CRED_NEW, &entry->cr_flags) ||
+ refcount_read(&entry->cr_count) == 0)
+ continue;
+ cred = entry;
break;
}
- spin_lock(&cache->lock);
- if (test_bit(RPCAUTH_CRED_HASHED, &entry->cr_flags) == 0) {
- spin_unlock(&cache->lock);
- continue;
- }
cred = get_rpccred(entry);
- spin_unlock(&cache->lock);
- break;
+ if (cred)
+ break;
}
rcu_read_unlock();
@@ -594,11 +617,13 @@ rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
if (!entry->cr_ops->crmatch(acred, entry, flags))
continue;
cred = get_rpccred(entry);
- break;
+ if (cred)
+ break;
}
if (cred == NULL) {
cred = new;
set_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
+ refcount_inc(&cred->cr_count);
hlist_add_head_rcu(&cred->cr_hash, &cache->hashtable[nr]);
} else
list_add_tail(&new->cr_lru, &free);
@@ -645,7 +670,7 @@ rpcauth_init_cred(struct rpc_cred *cred, const struct auth_cred *acred,
{
INIT_HLIST_NODE(&cred->cr_hash);
INIT_LIST_HEAD(&cred->cr_lru);
- atomic_set(&cred->cr_count, 1);
+ refcount_set(&cred->cr_count, 1);
cred->cr_auth = auth;
cred->cr_ops = ops;
cred->cr_expire = jiffies;
@@ -713,36 +738,29 @@ put_rpccred(struct rpc_cred *cred)
{
if (cred == NULL)
return;
- /* Fast path for unhashed credentials */
- if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) == 0) {
- if (atomic_dec_and_test(&cred->cr_count))
- cred->cr_ops->crdestroy(cred);
- return;
- }
-
- if (!atomic_dec_and_lock(&cred->cr_count, &rpc_credcache_lock))
- return;
- if (!list_empty(&cred->cr_lru)) {
- number_cred_unused--;
- list_del_init(&cred->cr_lru);
- }
- if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0) {
- if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0) {
- cred->cr_expire = jiffies;
- list_add_tail(&cred->cr_lru, &cred_unused);
- number_cred_unused++;
- goto out_nodestroy;
- }
- if (!rpcauth_unhash_cred(cred)) {
- /* We were hashed and someone looked us up... */
- goto out_nodestroy;
- }
+ rcu_read_lock();
+ if (refcount_dec_and_test(&cred->cr_count))
+ goto destroy;
+ if (refcount_read(&cred->cr_count) != 1 ||
+ !test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags))
+ goto out;
+ if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0) {
+ cred->cr_expire = jiffies;
+ rpcauth_lru_add(cred);
+ /* Race breaker */
+ if (unlikely(!test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags)))
+ rpcauth_lru_remove(cred);
+ } else if (rpcauth_unhash_cred(cred)) {
+ rpcauth_lru_remove(cred);
+ if (refcount_dec_and_test(&cred->cr_count))
+ goto destroy;
}
- spin_unlock(&rpc_credcache_lock);
- cred->cr_ops->crdestroy(cred);
+out:
+ rcu_read_unlock();
return;
-out_nodestroy:
- spin_unlock(&rpc_credcache_lock);
+destroy:
+ rcu_read_unlock();
+ cred->cr_ops->crdestroy(cred);
}
EXPORT_SYMBOL_GPL(put_rpccred);
@@ -817,6 +835,16 @@ rpcauth_unwrap_resp(struct rpc_task *task, kxdrdproc_t decode, void *rqstp,
return rpcauth_unwrap_req_decode(decode, rqstp, data, obj);
}
+bool
+rpcauth_xmit_need_reencode(struct rpc_task *task)
+{
+ struct rpc_cred *cred = task->tk_rqstp->rq_cred;
+
+ if (!cred || !cred->cr_ops->crneed_reencode)
+ return false;
+ return cred->cr_ops->crneed_reencode(task);
+}
+
int
rpcauth_refreshcred(struct rpc_task *task)
{