Techwizz/kernel-fxtec-pro1x
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

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

Browse source 
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>
This commit is contained in:
Bob Liu 2012-07-11 14:02:35 -07:00 committed by Linus Torvalds
parent b59f6d1feb
commit fea9f718b3
1 changed files with 1 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

1
fs/ramfs/file-nommu.c
View file

@ -110,6 +110,7 @@ int ramfs_nommu_expand_for_mapping(struct inode *inode, size_t newsize)
/* prevent the page from being discarded on memory pressure */
SetPageDirty(page);
SetPageUptodate(page);
unlock_page(page);
put_page(page);