SUNRPC: Convert the credential garbage collector into a shrinker callback
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c
index cf1198d..81f4c77 100644
--- a/net/sunrpc/auth.c
+++ b/net/sunrpc/auth.c
@@ -26,6 +26,7 @@
};
static LIST_HEAD(cred_unused);
+static unsigned long number_cred_unused;
static u32
pseudoflavor_to_flavor(u32 flavor) {
@@ -136,7 +137,7 @@
* 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 @@
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 @@
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 @@
/*
* 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 @@
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 @@
cred = ERR_PTR(res);
}
}
- rpcauth_gc_credcache(cache, &free);
rpcauth_destroy_credlist(&free);
out:
return cred;
@@ -408,13 +417,16 @@
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 @@
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);
+}