[PATCH] ncpfs: Use struct pid to track the userspace watchdog process

This patch converts the tracking of the user space watchdog process from using
a pid_t to use struct pid. This makes us safe from pid wrap around issues and
prepares the way for the pid namespace.

Signed-off-by: Eric W. Biederman <[e-mail]>
Cc: Petr Vandrovec <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

fs/ncpfs/inode.c

···
 	data->flags = 0;
 	data->int_flags = 0;
 	data->mounted_uid = 0;
-	data->wdog_pid = -1;
+	data->wdog_pid = NULL;
 	data->ncp_fd = ~0;
 	data->time_out = 10;
 	data->retry_count = 20;
···
 				data->flags = optint;
 				break;
 			case 'w':
-				data->wdog_pid = optint;
+				data->wdog_pid = find_get_pid(optint);
 				break;
 			case 'n':
 				data->ncp_fd = optint;
···
 				data.flags = md->flags;
 				data.int_flags = NCP_IMOUNT_LOGGEDIN_POSSIBLE;
 				data.mounted_uid = md->mounted_uid;
-				data.wdog_pid = md->wdog_pid;
+				data.wdog_pid = find_get_pid(md->wdog_pid);
 				data.ncp_fd = md->ncp_fd;
 				data.time_out = md->time_out;
 				data.retry_count = md->retry_count;
···
 				data.flags = md->flags;
 				data.int_flags = 0;
 				data.mounted_uid = md->mounted_uid;
-				data.wdog_pid = md->wdog_pid;
+				data.wdog_pid = find_get_pid(md->wdog_pid);
 				data.ncp_fd = md->ncp_fd;
 				data.time_out = md->time_out;
 				data.retry_count = md->retry_count;
···
 	if (server->info_filp)
 		fput(server->info_filp);
 	fput(server->ncp_filp);
-	kill_proc(server->m.wdog_pid, SIGTERM, 1);
+	kill_pid(server->m.wdog_pid, SIGTERM, 1);
+	put_pid(server->m.wdog_pid);
 
 	kfree(server->priv.data);
 	kfree(server->auth.object_name);

include/linux/ncp_mount.h

···
 	unsigned int	 int_flags;	/* internal flags */
 #define NCP_IMOUNT_LOGGEDIN_POSSIBLE	0x0001
 	__kernel_uid32_t mounted_uid;	/* Who may umount() this filesystem? */
-	__kernel_pid_t   wdog_pid;		/* Who cares for our watchdog packets? */
+	struct pid      *wdog_pid;	/* Who cares for our watchdog packets? */
 	unsigned int     ncp_fd;	/* The socket to the ncp port */
 	unsigned int     time_out;	/* How long should I wait after
 					   sending a NCP request? */