[PATCH] file: modify struct fown_struct to use a struct pid

File handles can be requested to send sigio and sigurg to processes.  By
tracking the destination processes using struct pid instead of pid_t we make
the interface safe from all potential pid wrap around problems.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 2e29a2e..91c0b2a 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -684,7 +684,8 @@
 
 struct fown_struct {
 	rwlock_t lock;          /* protects pid, uid, euid fields */
-	int pid;		/* pid or -pgrp where SIGIO should be sent */
+	struct pid *pid;	/* pid or -pgrp where SIGIO should be sent */
+	enum pid_type pid_type;	/* Kind of process group SIGIO should be sent to */
 	uid_t uid, euid;	/* uid/euid of process setting the owner */
 	int signum;		/* posix.1b rt signal to be delivered on IO */
 };
@@ -880,8 +881,10 @@
 /* only for net: no internal synchronization */
 extern void __kill_fasync(struct fasync_struct *, int, int);
 
+extern int __f_setown(struct file *filp, struct pid *, enum pid_type, int force);
 extern int f_setown(struct file *filp, unsigned long arg, int force);
 extern void f_delown(struct file *filp);
+extern pid_t f_getown(struct file *filp);
 extern int send_sigurg(struct fown_struct *fown);
 
 /*