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>
diff --git a/fs/ramfs/file-nommu.c b/fs/ramfs/file-nommu.c
index fbb0b47..d5378d0 100644
--- a/fs/ramfs/file-nommu.c
+++ b/fs/ramfs/file-nommu.c
@@ -110,6 +110,7 @@
/* prevent the page from being discarded on memory pressure */
SetPageDirty(page);
+ SetPageUptodate(page);
unlock_page(page);
put_page(page);