SUNRPC: Make the credential cache hashtable size configurable

This patch allows the user to configure the credential cache hashtable size
using a new module parameter: auth_hashtable_size
When set, this parameter will be rounded up to the nearest power of two,
with a maximum allowed value of 1024 elements.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Trond Myklebust 2010-07-31 14:29:08 -04:00
parent 988664a0f6
commit 241269bd0b
2 changed files with 56 additions and 13 deletions

View file

@ -61,14 +61,7 @@ struct rpc_cred {
/*
* Client authentication handle
*/
#define RPC_CREDCACHE_HASHBITS 4
#define RPC_CREDCACHE_NR (1 << RPC_CREDCACHE_HASHBITS)
struct rpc_cred_cache {
struct hlist_head hashtable[RPC_CREDCACHE_NR];
unsigned int hashbits;
spinlock_t lock;
};
struct rpc_cred_cache;
struct rpc_authops;
struct rpc_auth {
unsigned int au_cslack; /* call cred size estimate */

View file

@ -19,6 +19,15 @@
# define RPCDBG_FACILITY RPCDBG_AUTH
#endif
#define RPC_CREDCACHE_DEFAULT_HASHBITS (4)
struct rpc_cred_cache {
struct hlist_head *hashtable;
unsigned int hashbits;
spinlock_t lock;
};
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 */
@ -29,6 +38,42 @@ static const struct rpc_authops *auth_flavors[RPC_AUTH_MAXFLAVOR] = {
static LIST_HEAD(cred_unused);
static unsigned long number_cred_unused;
#define MAX_HASHTABLE_BITS (10)
static int param_set_hashtbl_sz(const char *val, struct kernel_param *kp)
{
unsigned long num;
unsigned int nbits;
int ret;
if (!val)
goto out_inval;
ret = strict_strtoul(val, 0, &num);
if (ret == -EINVAL)
goto out_inval;
nbits = fls(num);
if (num > (1U << nbits))
nbits++;
if (nbits > MAX_HASHTABLE_BITS || nbits < 2)
goto out_inval;
*(unsigned int *)kp->arg = nbits;
return 0;
out_inval:
return -EINVAL;
}
static int param_get_hashtbl_sz(char *buffer, struct kernel_param *kp)
{
unsigned int nbits;
nbits = *(unsigned int *)kp->arg;
return sprintf(buffer, "%u", 1U << nbits);
}
#define param_check_hashtbl_sz(name, p) __param_check(name, p, unsigned int);
module_param_named(auth_hashtable_size, auth_hashbits, hashtbl_sz, 0644);
MODULE_PARM_DESC(auth_hashtable_size, "RPC credential cache hashtable size");
static u32
pseudoflavor_to_flavor(u32 flavor) {
if (flavor >= RPC_AUTH_MAXFLAVOR)
@ -146,18 +191,22 @@ rpcauth_init_credcache(struct rpc_auth *auth)
{
struct rpc_cred_cache *new;
unsigned int hashsize;
int i;
new = kmalloc(sizeof(*new), GFP_KERNEL);
if (!new)
return -ENOMEM;
new->hashbits = RPC_CREDCACHE_HASHBITS;
goto out_nocache;
new->hashbits = auth_hashbits;
hashsize = 1U << new->hashbits;
for (i = 0; i < hashsize; i++)
INIT_HLIST_HEAD(&new->hashtable[i]);
new->hashtable = kcalloc(hashsize, sizeof(new->hashtable[0]), GFP_KERNEL);
if (!new->hashtable)
goto out_nohashtbl;
spin_lock_init(&new->lock);
auth->au_credcache = new;
return 0;
out_nohashtbl:
kfree(new);
out_nocache:
return -ENOMEM;
}
EXPORT_SYMBOL_GPL(rpcauth_init_credcache);
@ -220,6 +269,7 @@ rpcauth_destroy_credcache(struct rpc_auth *auth)
if (cache) {
auth->au_credcache = NULL;
rpcauth_clear_credcache(cache);
kfree(cache->hashtable);
kfree(cache);
}
}