SUNRPC: Protect creds against early garbage collection

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Trond Myklebust 2008-04-14 18:13:37 -04:00
parent a2b2bb8822
commit d2b8314163
1 changed files with 8 additions and 0 deletions

View File

@ -220,6 +220,9 @@ rpcauth_destroy_credcache(struct rpc_auth *auth)
}
EXPORT_SYMBOL_GPL(rpcauth_destroy_credcache);
#define RPC_AUTH_EXPIRY_MORATORIUM (60 * HZ)
/*
* Remove stale credentials. Avoid sleeping inside the loop.
*/
@ -228,6 +231,7 @@ rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
{
spinlock_t *cache_lock;
struct rpc_cred *cred;
unsigned long expired = jiffies - RPC_AUTH_EXPIRY_MORATORIUM;
while (!list_empty(&cred_unused)) {
cred = list_entry(cred_unused.next, struct rpc_cred, cr_lru);
@ -235,6 +239,10 @@ rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
number_cred_unused--;
if (atomic_read(&cred->cr_count) != 0)
continue;
/* Enforce a 5 second garbage collection moratorium */
if (time_in_range(cred->cr_expire, expired, jiffies) &&
test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0)
continue;
cache_lock = &cred->cr_auth->au_credcache->lock;
spin_lock(cache_lock);
if (atomic_read(&cred->cr_count) == 0) {