]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
fs: ramfs: file-nommu: add SetPageUptodate()
authorBob Liu <lliubbo@gmail.com>
Wed, 11 Jul 2012 21:02:35 +0000 (14:02 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Wed, 11 Jul 2012 23:04:47 +0000 (16:04 -0700)
commitfea9f718b3d68147f162ed2d870183ce5e0ad8d8
treef255c59e2c4d8712c3034898c82585b3133d4b51
parentb59f6d1febd6cbe9fae4589bf72da0ed32bc69e0
fs: ramfs: file-nommu: add SetPageUptodate()

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>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/ramfs/file-nommu.c