From f8e252d7a5687e0c9f11d3c36e3a867a1e64b418 Mon Sep 17 00:00:00 2001 From: Bob Liu Date: Wed, 11 Jul 2012 14:02:35 -0700 Subject: 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 Cc: Hugh Dickins Cc: David Howells Cc: Geert Uytterhoeven Cc: Greg Ungerer Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- fs/ramfs/file-nommu.c | 1 + 1 file changed, 1 insertion(+) (limited to 'fs/ramfs') 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 @@ 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); -- cgit v1.1