Commit fea9f718 authored by Bob Liu's avatar Bob Liu Committed by Linus Torvalds

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: default avatarBob 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent b59f6d1f
......@@ -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);
......
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