From: Trond Myklebust <Trond.Myklebust@netapp.com>
Date: Mon, 14 Apr 2008 22:13:37 +0000 (-0400)
Subject: SUNRPC: Protect creds against early garbage collection
X-Git-Tag: v2.6.26-rc1~1082^2^2~9
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d2b831416365e8b1f27809b62d5e4260883956cc;p=linux-2.6

SUNRPC: Protect creds against early garbage collection

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
---

diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c
index 0632cd0a1a..6bfea9ed68 100644
--- a/net/sunrpc/auth.c
+++ b/net/sunrpc/auth.c
@@ -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) {