From: Bob Liu <lliubbo@gmail.com>
Date: Wed, 11 Jul 2012 21:02:35 +0000 (-0700)
Subject: fs: ramfs: file-nommu: add SetPageUptodate()
X-Git-Tag: v3.2.24~67
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3501ec357a73226d2b3c1bd204d97926f61b3eae;p=pandora-kernel.git

fs: ramfs: file-nommu: add SetPageUptodate()

commit fea9f718b3d68147f162ed2d870183ce5e0ad8d8 upstream.

There is a bug in the below scenario for !CONFIG_MMU:

 1. create a new file
 2. mmap the file and write to it
 3. read the file can't get the correct value

Because

  sys_read() -> generic_file_aio_read() -> simple_readpage() -> clear_page()

which causes the page to be zeroed.

Add SetPageUptodate() to ramfs_nommu_expand_for_mapping() so that
generic_file_aio_read() do not call simple_readpage().

Signed-off-by: Bob Liu <lliubbo@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---

Reading git-diff-tree failed