fb: defio nopage

Convert fb defio from nopage to fault.
Switch from OOM to SIGBUS if the resource is not available.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Jaya Kumar <jayakumar.lkml@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/Documentation/fb/deferred_io.txt b/Documentation/fb/deferred_io.txt
index 63883a8..7483283 100644
--- a/Documentation/fb/deferred_io.txt
+++ b/Documentation/fb/deferred_io.txt
@@ -7,10 +7,10 @@
 works:
 
 - userspace app like Xfbdev mmaps framebuffer
-- deferred IO and driver sets up nopage and page_mkwrite handlers
+- deferred IO and driver sets up fault and page_mkwrite handlers
 - userspace app tries to write to mmaped vaddress
-- we get pagefault and reach nopage handler
-- nopage handler finds and returns physical page
+- we get pagefault and reach fault handler
+- fault handler finds and returns physical page
 - we get page_mkwrite where we add this page to a list
 - schedule a workqueue task to be run after a delay
 - app continues writing to that page with no additional cost. this is