SUNRPC: Convert the credential garbage collector into a shrinker callback

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Trond Myklebust 2007-06-25 17:11:20 -04:00
parent 9499b4341b
commit f5c2187cfe
5 changed files with 52 additions and 29 deletions

View File

@ -64,8 +64,6 @@ struct rpc_cred {
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 */
};
struct rpc_authops;
@ -128,6 +126,8 @@ extern const struct rpc_authops authunix_ops;
extern const struct rpc_authops authnull_ops;
void __init rpc_init_authunix(void);
void __init rpcauth_init_module(void);
void __exit rpcauth_remove_module(void);
int rpcauth_register(const struct rpc_authops *);
int rpcauth_unregister(const struct rpc_authops *);
@ -147,7 +147,7 @@ int rpcauth_unwrap_resp(struct rpc_task *task, kxdrproc_t decode, void *rqstp,
int rpcauth_refreshcred(struct rpc_task *);
void rpcauth_invalcred(struct rpc_task *);
int rpcauth_uptodatecred(struct rpc_task *);
int rpcauth_init_credcache(struct rpc_auth *, unsigned long);
int rpcauth_init_credcache(struct rpc_auth *);
void rpcauth_destroy_credcache(struct rpc_auth *);
void rpcauth_clear_credcache(struct rpc_cred_cache *);

View File

@ -26,6 +26,7 @@ static const struct rpc_authops *auth_flavors[RPC_AUTH_MAXFLAVOR] = {
};
static LIST_HEAD(cred_unused);
static unsigned long number_cred_unused;
static u32
pseudoflavor_to_flavor(u32 flavor) {
@ -136,7 +137,7 @@ rpcauth_unhash_cred(struct rpc_cred *cred)
* Initialize RPC credential cache
*/
int
rpcauth_init_credcache(struct rpc_auth *auth, unsigned long expire)
rpcauth_init_credcache(struct rpc_auth *auth)
{
struct rpc_cred_cache *new;
int i;
@ -147,8 +148,6 @@ rpcauth_init_credcache(struct rpc_auth *auth, unsigned long expire)
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;
return 0;
}
@ -187,7 +186,11 @@ rpcauth_clear_credcache(struct rpc_cred_cache *cache)
while (!hlist_empty(head)) {
cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
get_rpccred(cred);
list_move_tail(&cred->cr_lru, &free);
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);
}
}
@ -214,18 +217,16 @@ rpcauth_destroy_credcache(struct rpc_auth *auth)
/*
* Remove stale credentials. Avoid sleeping inside the loop.
*/
static void
rpcauth_prune_expired(struct list_head *free)
static int
rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
{
spinlock_t *cache_lock;
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);
number_cred_unused--;
if (atomic_read(&cred->cr_count) != 0)
continue;
cache_lock = &cred->cr_auth->au_credcache->lock;
@ -234,23 +235,32 @@ rpcauth_prune_expired(struct list_head *free)
get_rpccred(cred);
list_add_tail(&cred->cr_lru, free);
rpcauth_unhash_cred_locked(cred);
nr_to_scan--;
}
spin_unlock(cache_lock);
if (nr_to_scan == 0)
break;
}
return nr_to_scan;
}
/*
* Run garbage collector.
* Run memory cache shrinker.
*/
static void
rpcauth_gc_credcache(struct rpc_cred_cache *cache, struct list_head *free)
static int
rpcauth_cache_shrinker(int nr_to_scan, gfp_t gfp_mask)
{
if (list_empty(&cred_unused) || time_before(jiffies, cache->nextgc))
return;
LIST_HEAD(free);
int res;
if (list_empty(&cred_unused))
return 0;
spin_lock(&rpc_credcache_lock);
cache->nextgc = jiffies + cache->expire;
rpcauth_prune_expired(free);
nr_to_scan = rpcauth_prune_expired(&free, nr_to_scan);
res = (number_cred_unused / 100) * sysctl_vfs_cache_pressure;
spin_unlock(&rpc_credcache_lock);
rpcauth_destroy_credlist(&free);
return res;
}
/*
@ -318,7 +328,6 @@ found:
cred = ERR_PTR(res);
}
}
rpcauth_gc_credcache(cache, &free);
rpcauth_destroy_credlist(&free);
out:
return cred;
@ -408,13 +417,16 @@ put_rpccred(struct rpc_cred *cred)
need_lock:
if (!atomic_dec_and_lock(&cred->cr_count, &rpc_credcache_lock))
return;
if (!list_empty(&cred->cr_lru))
if (!list_empty(&cred->cr_lru)) {
number_cred_unused--;
list_del_init(&cred->cr_lru);
}
if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
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);
number_cred_unused++;
spin_unlock(&rpc_credcache_lock);
return;
}
@ -520,3 +532,18 @@ rpcauth_uptodatecred(struct rpc_task *task)
return cred == NULL ||
test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0;
}
static struct shrinker *rpc_cred_shrinker;
void __init rpcauth_init_module(void)
{
rpc_init_authunix();
rpc_cred_shrinker = set_shrinker(DEFAULT_SEEKS, rpcauth_cache_shrinker);
}
void __exit rpcauth_remove_module(void)
{
if (rpc_cred_shrinker != NULL)
remove_shrinker(rpc_cred_shrinker);
}

View File

@ -64,7 +64,6 @@ static const struct rpc_credops gss_credops;
#define NFS_NGROUPS 16
#define GSS_CRED_EXPIRE (60 * HZ) /* XXX: reasonable? */
#define GSS_CRED_SLACK 1024 /* XXX: unused */
/* length of a krb5 verifier (48), plus data added before arguments when
* using integrity (two 4-byte integers): */
@ -643,7 +642,7 @@ gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
goto err_put_mech;
}
err = rpcauth_init_credcache(auth, GSS_CRED_EXPIRE);
err = rpcauth_init_credcache(auth);
if (err)
goto err_unlink_pipe;

View File

@ -21,8 +21,6 @@ struct unx_cred {
};
#define uc_uid uc_base.cr_uid
#define UNX_CRED_EXPIRE (60 * HZ)
#define UNX_WRITESLACK (21 + (UNX_MAXNODENAME >> 2))
#ifdef RPC_DEBUG
@ -38,8 +36,7 @@ unx_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
{
dprintk("RPC: creating UNIX authenticator for client %p\n",
clnt);
if (atomic_inc_return(&unix_auth.au_count) == 1)
unix_cred_cache.nextgc = jiffies + (unix_cred_cache.expire >> 1);
atomic_inc(&unix_auth.au_count);
return &unix_auth;
}
@ -232,7 +229,6 @@ const struct rpc_authops authunix_ops = {
static
struct rpc_cred_cache unix_cred_cache = {
.expire = UNX_CRED_EXPIRE,
};
static

View File

@ -152,7 +152,7 @@ init_sunrpc(void)
cache_register(&ip_map_cache);
cache_register(&unix_gid_cache);
init_socket_xprt();
rpc_init_authunix();
rpcauth_init_module();
out:
return err;
}
@ -160,6 +160,7 @@ out:
static void __exit
cleanup_sunrpc(void)
{
rpcauth_remove_module();
cleanup_socket_xprt();
unregister_rpc_pipefs();
rpc_destroy_mempool();