Commit e092bdcd authored by Trond Myklebust's avatar Trond Myklebust

SUNRPC: cleanup rpc credential cache garbage collection

Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent fc432dd9
......@@ -34,6 +34,7 @@ struct rpc_auth;
struct rpc_credops;
struct rpc_cred {
struct hlist_node cr_hash; /* hash chain */
struct list_head cr_lru; /* lru garbage collection */
struct rpc_auth * cr_auth;
const struct rpc_credops *cr_ops;
#ifdef RPC_DEBUG
......
......@@ -25,6 +25,8 @@ static const struct rpc_authops *auth_flavors[RPC_AUTH_MAXFLAVOR] = {
NULL, /* others can be loadable modules */
};
static LIST_HEAD(cred_unused);
static u32
pseudoflavor_to_flavor(u32 flavor) {
if (flavor >= RPC_AUTH_MAXFLAVOR)
......@@ -134,13 +136,13 @@ rpcauth_init_credcache(struct rpc_auth *auth, unsigned long expire)
* Destroy a list of credentials
*/
static inline
void rpcauth_destroy_credlist(struct hlist_head *head)
void rpcauth_destroy_credlist(struct list_head *head)
{
struct rpc_cred *cred;
while (!hlist_empty(head)) {
cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
hlist_del_init(&cred->cr_hash);
while (!list_empty(head)) {
cred = list_entry(head->next, struct rpc_cred, cr_lru);
list_del_init(&cred->cr_lru);
put_rpccred(cred);
}
}
......@@ -152,17 +154,20 @@ void rpcauth_destroy_credlist(struct hlist_head *head)
void
rpcauth_clear_credcache(struct rpc_cred_cache *cache)
{
HLIST_HEAD(free);
struct hlist_node *pos, *next;
LIST_HEAD(free);
struct hlist_head *head;
struct rpc_cred *cred;
int i;
spin_lock(&rpc_credcache_lock);
for (i = 0; i < RPC_CREDCACHE_NR; i++) {
hlist_for_each_safe(pos, next, &cache->hashtable[i]) {
cred = hlist_entry(pos, struct rpc_cred, cr_hash);
__hlist_del(&cred->cr_hash);
hlist_add_head(&cred->cr_hash, &free);
head = &cache->hashtable[i];
while (!hlist_empty(head)) {
cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
get_rpccred(cred);
list_move_tail(&cred->cr_lru, &free);
smp_wmb();
hlist_del_init(&cred->cr_hash);
}
}
spin_unlock(&rpc_credcache_lock);
......@@ -184,38 +189,39 @@ rpcauth_destroy_credcache(struct rpc_auth *auth)
}
}
/*
* Remove stale credentials. Avoid sleeping inside the loop.
*/
static void
rpcauth_prune_expired(struct rpc_auth *auth, struct rpc_cred *cred, struct hlist_head *free)
rpcauth_prune_expired(struct list_head *free)
{
if (atomic_read(&cred->cr_count) != 1)
return;
if (time_after(jiffies, cred->cr_expire + auth->au_credcache->expire))
clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0) {
__hlist_del(&cred->cr_hash);
hlist_add_head(&cred->cr_hash, free);
struct rpc_cred *cred;
while (!list_empty(&cred_unused)) {
cred = list_entry(cred_unused.next, struct rpc_cred, cr_lru);
if (time_after(jiffies, cred->cr_expire +
cred->cr_auth->au_credcache->expire))
break;
list_del_init(&cred->cr_lru);
if (atomic_read(&cred->cr_count) != 0)
continue;
get_rpccred(cred);
list_add_tail(&cred->cr_lru, free);
smp_wmb();
hlist_del_init(&cred->cr_hash);
}
}
/*
* Remove stale credentials. Avoid sleeping inside the loop.
* Run garbage collector.
*/
static void
rpcauth_gc_credcache(struct rpc_auth *auth, struct hlist_head *free)
rpcauth_gc_credcache(struct rpc_cred_cache *cache, struct list_head *free)
{
struct rpc_cred_cache *cache = auth->au_credcache;
struct hlist_node *pos, *next;
struct rpc_cred *cred;
int i;
dprintk("RPC: gc'ing RPC credentials for auth %p\n", auth);
for (i = 0; i < RPC_CREDCACHE_NR; i++) {
hlist_for_each_safe(pos, next, &cache->hashtable[i]) {
cred = hlist_entry(pos, struct rpc_cred, cr_hash);
rpcauth_prune_expired(auth, cred, free);
}
}
if (time_before(jiffies, cache->nextgc))
return;
cache->nextgc = jiffies + cache->expire;
rpcauth_prune_expired(free);
}
/*
......@@ -225,39 +231,35 @@ struct rpc_cred *
rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
int flags)
{
LIST_HEAD(free);
struct rpc_cred_cache *cache = auth->au_credcache;
HLIST_HEAD(free);
struct hlist_node *pos, *next;
struct hlist_node *pos;
struct rpc_cred *new = NULL,
*cred = NULL;
*cred = NULL,
*entry;
int nr = 0;
if (!(flags & RPCAUTH_LOOKUP_ROOTCREDS))
nr = acred->uid & RPC_CREDCACHE_MASK;
retry:
spin_lock(&rpc_credcache_lock);
if (time_before(cache->nextgc, jiffies))
rpcauth_gc_credcache(auth, &free);
hlist_for_each_safe(pos, next, &cache->hashtable[nr]) {
struct rpc_cred *entry;
entry = hlist_entry(pos, struct rpc_cred, cr_hash);
if (entry->cr_ops->crmatch(acred, entry, flags)) {
hlist_for_each_entry(entry, pos, &cache->hashtable[nr], cr_hash) {
if (!entry->cr_ops->crmatch(acred, entry, flags))
continue;
cred = get_rpccred(entry);
hlist_del(&entry->cr_hash);
cred = entry;
break;
}
rpcauth_prune_expired(auth, entry, &free);
}
if (new) {
if (cred)
hlist_add_head(&new->cr_hash, &free);
list_add_tail(&new->cr_lru, &free);
else
cred = new;
}
if (cred) {
hlist_add_head(&cred->cr_hash, &cache->hashtable[nr]);
get_rpccred(cred);
}
rpcauth_gc_credcache(cache, &free);
spin_unlock(&rpc_credcache_lock);
rpcauth_destroy_credlist(&free);
......@@ -303,6 +305,7 @@ rpcauth_init_cred(struct rpc_cred *cred, const struct auth_cred *acred,
struct rpc_auth *auth, const struct rpc_credops *ops)
{
INIT_HLIST_NODE(&cred->cr_hash);
INIT_LIST_HEAD(&cred->cr_lru);
atomic_set(&cred->cr_count, 1);
cred->cr_auth = auth;
cred->cr_ops = ops;
......@@ -353,9 +356,29 @@ rpcauth_holdcred(struct rpc_task *task)
void
put_rpccred(struct rpc_cred *cred)
{
cred->cr_expire = jiffies;
/* Fast path for unhashed credentials */
if (!hlist_unhashed(&cred->cr_hash))
goto need_lock;
if (!atomic_dec_and_test(&cred->cr_count))
return;
goto out_destroy;
need_lock:
if (!atomic_dec_and_lock(&cred->cr_count, &rpc_credcache_lock))
return;
if (!list_empty(&cred->cr_lru))
list_del_init(&cred->cr_lru);
if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
hlist_del(&cred->cr_hash);
else if (!hlist_unhashed(&cred->cr_hash)) {
cred->cr_expire = jiffies;
list_add_tail(&cred->cr_lru, &cred_unused);
spin_unlock(&rpc_credcache_lock);
return;
}
spin_unlock(&rpc_credcache_lock);
out_destroy:
cred->cr_ops->crdestroy(cred);
}
......
......@@ -133,6 +133,7 @@ const struct rpc_credops null_credops = {
static
struct rpc_cred null_cred = {
.cr_lru = LIST_HEAD_INIT(null_cred.cr_lru),
.cr_auth = &null_auth,
.cr_ops = &null_credops,
.cr_count = ATOMIC_INIT(1),
......
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