shift current_cred() from __f_setown() to f_modown()

Shift current_cred() from __f_setown() to f_modown(). This reduces
the number of arguments and saves 48 bytes from fs/fcntl.o.

[ Note: this doesn't clear euid/uid when pid is set to NULL.  But if
  f_owner.pid == NULL we never use f_owner.uid/euid.  Otherwise we'd
  have a bug anyway: we must not send signals if pid was reset to NULL.  ]

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 10 insertions, 7 deletions

diff --git a/fs/fcntl.c b/fs/fcntl.c
index 1ad703150dee..f9c03ca3b2f4 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -198,15 +198,19 @@ static int setfl(int fd, struct file * filp, unsigned long arg)
 }
 
 static void f_modown(struct file *filp, struct pid *pid, enum pid_type type,
-                     uid_t uid, uid_t euid, int force)
+                     int force)
 {
         write_lock_irq(&filp->f_owner.lock);
         if (force || !filp->f_owner.pid) {
                 put_pid(filp->f_owner.pid);
                 filp->f_owner.pid = get_pid(pid);
                 filp->f_owner.pid_type = type;
-                filp->f_owner.uid = uid;
-                filp->f_owner.euid = euid;
+
+                if (pid) {
+                        const struct cred *cred = current_cred();
+                        filp->f_owner.uid = cred->uid;
+                        filp->f_owner.euid = cred->euid;
+                }
         }
         write_unlock_irq(&filp->f_owner.lock);
 }
@@ -214,14 +218,13 @@ static void f_modown(struct file *filp, struct pid *pid, enum pid_type type,
 int __f_setown(struct file *filp, struct pid *pid, enum pid_type type,
                 int force)
 {
-        const struct cred *cred = current_cred();
         int err;
-        
+
         err = security_file_set_fowner(filp);
         if (err)
                 return err;
 
-        f_modown(filp, pid, type, cred->uid, cred->euid, force);
+        f_modown(filp, pid, type, force);
         return 0;
 }
 EXPORT_SYMBOL(__f_setown);
@@ -247,7 +250,7 @@ EXPORT_SYMBOL(f_setown);
 
 void f_delown(struct file *filp)
 {
-        f_modown(filp, NULL, PIDTYPE_PID, 0, 0, 1);
+        f_modown(filp, NULL, PIDTYPE_PID, 1);
 }
 
 pid_t f_getown(struct file *filp)