[PATCH] Avoid deadlock in sync_page_io by using GFP_NOIO

..as sync_page_io can be called on the write-out path.

Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>