[PATCH] usb-storage: wait for URB to complete

We all failed to notice that Franck's recent update to usb-storage allowed
an URB to complete after its context data was no longer valid.  This patch
(as746) makes the driver wait for the URB to complete whenever there's a
timeout.

Although timeouts in usb-storage are relatively uncommon, they do occur.
Without this patch the code in 2.6.18-rc1 will fault within an interrupt
handler, which is not nice at all.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/usb/storage/transport.c

@@ -180,7 +180,7 @@ static int usb_stor_msg_common(struct us_data *us, int timeout)
 	if (timeleft <= 0) {
 		US_DEBUGP("%s -- cancelling URB\n",
 			  timeleft == 0 ? "Timeout" : "Signal");
-		usb_unlink_urb(us->current_urb);
+		usb_kill_urb(us->current_urb);
 	}
 
 	/* return the URB status */