Created a function for setting timeouts on keys

The keyctl_set_timeout function isn't exported to other parts of the
kernel, but I want to use it for the NFS idmapper.  I already have the
key, but I wanted a generic way to set the timeout.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

2 files changed, 22 insertions, 16 deletions

diff --git a/security/keys/key.c b/security/keys/key.c
index 7ada8019be1..06783cffb3a 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -671,6 +671,26 @@ found_kernel_type:
         return ktype;
 }
 
+void key_set_timeout(struct key *key, unsigned timeout)
+{
+        struct timespec now;
+        time_t expiry = 0;
+
+        /* make the changes with the locks held to prevent races */
+        down_write(&key->sem);
+
+        if (timeout > 0) {
+                now = current_kernel_time();
+                expiry = now.tv_sec + timeout;
+        }
+
+        key->expiry = expiry;
+        key_schedule_gc(key->expiry + key_gc_delay);
+
+        up_write(&key->sem);
+}
+EXPORT_SYMBOL_GPL(key_set_timeout);
+
 /*
  * Unlock a key type locked by key_type_lookup().
  */
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index 0b3f5d72af1..0a4a21d73f6 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -14,6 +14,7 @@
 #include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/syscalls.h>
+#include <linux/key.h>
 #include <linux/keyctl.h>
 #include <linux/fs.h>
 #include <linux/capability.h>
@@ -1244,10 +1245,8 @@ error:
  */
 long keyctl_set_timeout(key_serial_t id, unsigned timeout)
 {
-        struct timespec now;
         struct key *key, *instkey;
         key_ref_t key_ref;
-        time_t expiry;
         long ret;
 
         key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL,
@@ -1273,20 +1272,7 @@ long keyctl_set_timeout(key_serial_t id, unsigned timeout)
 
 okay:
         key = key_ref_to_ptr(key_ref);
-
-        /* make the changes with the locks held to prevent races */
-        down_write(&key->sem);
-
-        expiry = 0;
-        if (timeout > 0) {
-                now = current_kernel_time();
-                expiry = now.tv_sec + timeout;
-        }
-
-        key->expiry = expiry;
-        key_schedule_gc(key->expiry + key_gc_delay);
-
-        up_write(&key->sem);
+        key_set_timeout(key, timeout);
         key_put(key);
 
         ret = 0;