SUNRPC: cleanup rpc credential cache garbage collection

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Trond Myklebust 2007-06-23 19:45:36 -04:00
parent fc432dd907
commit e092bdcd93
3 changed files with 76 additions and 51 deletions

View File

@ -34,6 +34,7 @@ struct rpc_auth;
struct rpc_credops; struct rpc_credops;
struct rpc_cred { struct rpc_cred {
struct hlist_node cr_hash; /* hash chain */ struct hlist_node cr_hash; /* hash chain */
struct list_head cr_lru; /* lru garbage collection */
struct rpc_auth * cr_auth; struct rpc_auth * cr_auth;
const struct rpc_credops *cr_ops; const struct rpc_credops *cr_ops;
#ifdef RPC_DEBUG #ifdef RPC_DEBUG

View File

@ -25,6 +25,8 @@ static const struct rpc_authops *auth_flavors[RPC_AUTH_MAXFLAVOR] = {
NULL, /* others can be loadable modules */ NULL, /* others can be loadable modules */
}; };
static LIST_HEAD(cred_unused);
static u32 static u32
pseudoflavor_to_flavor(u32 flavor) { pseudoflavor_to_flavor(u32 flavor) {
if (flavor >= RPC_AUTH_MAXFLAVOR) if (flavor >= RPC_AUTH_MAXFLAVOR)
@ -134,13 +136,13 @@ rpcauth_init_credcache(struct rpc_auth *auth, unsigned long expire)
* Destroy a list of credentials * Destroy a list of credentials
*/ */
static inline static inline
void rpcauth_destroy_credlist(struct hlist_head *head) void rpcauth_destroy_credlist(struct list_head *head)
{ {
struct rpc_cred *cred; struct rpc_cred *cred;
while (!hlist_empty(head)) { while (!list_empty(head)) {
cred = hlist_entry(head->first, struct rpc_cred, cr_hash); cred = list_entry(head->next, struct rpc_cred, cr_lru);
hlist_del_init(&cred->cr_hash); list_del_init(&cred->cr_lru);
put_rpccred(cred); put_rpccred(cred);
} }
} }
@ -152,17 +154,20 @@ void rpcauth_destroy_credlist(struct hlist_head *head)
void void
rpcauth_clear_credcache(struct rpc_cred_cache *cache) rpcauth_clear_credcache(struct rpc_cred_cache *cache)
{ {
HLIST_HEAD(free); LIST_HEAD(free);
struct hlist_node *pos, *next; struct hlist_head *head;
struct rpc_cred *cred; struct rpc_cred *cred;
int i; int i;
spin_lock(&rpc_credcache_lock); spin_lock(&rpc_credcache_lock);
for (i = 0; i < RPC_CREDCACHE_NR; i++) { for (i = 0; i < RPC_CREDCACHE_NR; i++) {
hlist_for_each_safe(pos, next, &cache->hashtable[i]) { head = &cache->hashtable[i];
cred = hlist_entry(pos, struct rpc_cred, cr_hash); while (!hlist_empty(head)) {
__hlist_del(&cred->cr_hash); cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
hlist_add_head(&cred->cr_hash, &free); get_rpccred(cred);
list_move_tail(&cred->cr_lru, &free);
smp_wmb();
hlist_del_init(&cred->cr_hash);
} }
} }
spin_unlock(&rpc_credcache_lock); spin_unlock(&rpc_credcache_lock);
@ -184,38 +189,39 @@ rpcauth_destroy_credcache(struct rpc_auth *auth)
} }
} }
static void
rpcauth_prune_expired(struct rpc_auth *auth, struct rpc_cred *cred, struct hlist_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);
}
}
/* /*
* Remove stale credentials. Avoid sleeping inside the loop. * Remove stale credentials. Avoid sleeping inside the loop.
*/ */
static void static void
rpcauth_gc_credcache(struct rpc_auth *auth, struct hlist_head *free) rpcauth_prune_expired(struct list_head *free)
{ {
struct rpc_cred_cache *cache = auth->au_credcache; struct rpc_cred *cred;
struct hlist_node *pos, *next;
struct rpc_cred *cred;
int i;
dprintk("RPC: gc'ing RPC credentials for auth %p\n", auth); while (!list_empty(&cred_unused)) {
for (i = 0; i < RPC_CREDCACHE_NR; i++) { cred = list_entry(cred_unused.next, struct rpc_cred, cr_lru);
hlist_for_each_safe(pos, next, &cache->hashtable[i]) { if (time_after(jiffies, cred->cr_expire +
cred = hlist_entry(pos, struct rpc_cred, cr_hash); cred->cr_auth->au_credcache->expire))
rpcauth_prune_expired(auth, cred, free); 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);
} }
}
/*
* Run garbage collector.
*/
static void
rpcauth_gc_credcache(struct rpc_cred_cache *cache, struct list_head *free)
{
if (time_before(jiffies, cache->nextgc))
return;
cache->nextgc = jiffies + cache->expire; 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, rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
int flags) int flags)
{ {
LIST_HEAD(free);
struct rpc_cred_cache *cache = auth->au_credcache; struct rpc_cred_cache *cache = auth->au_credcache;
HLIST_HEAD(free); struct hlist_node *pos;
struct hlist_node *pos, *next;
struct rpc_cred *new = NULL, struct rpc_cred *new = NULL,
*cred = NULL; *cred = NULL,
*entry;
int nr = 0; int nr = 0;
if (!(flags & RPCAUTH_LOOKUP_ROOTCREDS)) if (!(flags & RPCAUTH_LOOKUP_ROOTCREDS))
nr = acred->uid & RPC_CREDCACHE_MASK; nr = acred->uid & RPC_CREDCACHE_MASK;
retry: retry:
spin_lock(&rpc_credcache_lock); spin_lock(&rpc_credcache_lock);
if (time_before(cache->nextgc, jiffies)) hlist_for_each_entry(entry, pos, &cache->hashtable[nr], cr_hash) {
rpcauth_gc_credcache(auth, &free); if (!entry->cr_ops->crmatch(acred, entry, flags))
hlist_for_each_safe(pos, next, &cache->hashtable[nr]) { continue;
struct rpc_cred *entry; cred = get_rpccred(entry);
entry = hlist_entry(pos, struct rpc_cred, cr_hash); hlist_del(&entry->cr_hash);
if (entry->cr_ops->crmatch(acred, entry, flags)) { break;
hlist_del(&entry->cr_hash);
cred = entry;
break;
}
rpcauth_prune_expired(auth, entry, &free);
} }
if (new) { if (new) {
if (cred) if (cred)
hlist_add_head(&new->cr_hash, &free); list_add_tail(&new->cr_lru, &free);
else else
cred = new; cred = new;
} }
if (cred) { if (cred) {
hlist_add_head(&cred->cr_hash, &cache->hashtable[nr]); hlist_add_head(&cred->cr_hash, &cache->hashtable[nr]);
get_rpccred(cred);
} }
rpcauth_gc_credcache(cache, &free);
spin_unlock(&rpc_credcache_lock); spin_unlock(&rpc_credcache_lock);
rpcauth_destroy_credlist(&free); 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) struct rpc_auth *auth, const struct rpc_credops *ops)
{ {
INIT_HLIST_NODE(&cred->cr_hash); INIT_HLIST_NODE(&cred->cr_hash);
INIT_LIST_HEAD(&cred->cr_lru);
atomic_set(&cred->cr_count, 1); atomic_set(&cred->cr_count, 1);
cred->cr_auth = auth; cred->cr_auth = auth;
cred->cr_ops = ops; cred->cr_ops = ops;
@ -353,9 +356,29 @@ rpcauth_holdcred(struct rpc_task *task)
void void
put_rpccred(struct rpc_cred *cred) 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)) if (!atomic_dec_and_test(&cred->cr_count))
return; 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); cred->cr_ops->crdestroy(cred);
} }

View File

@ -133,6 +133,7 @@ const struct rpc_credops null_credops = {
static static
struct rpc_cred null_cred = { struct rpc_cred null_cred = {
.cr_lru = LIST_HEAD_INIT(null_cred.cr_lru),
.cr_auth = &null_auth, .cr_auth = &null_auth,
.cr_ops = &null_credops, .cr_ops = &null_credops,
.cr_count = ATOMIC_INIT(1), .cr_count = ATOMIC_INIT(1),