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authorBob Liu <lliubbo@gmail.com>2012-07-11 14:02:35 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-07-16 09:04:45 -0700
commit0fa627b15c842095b5147f381fa1943a6a46bb01 (patch)
tree4293cc0156d458583829aefff1eee7daa56df5fe /fs/ramfs
parent7a08b440fa93e036968102597c8a2ab809a9bdc4 (diff)
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 <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> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/ramfs')
-rw-r--r--fs/ramfs/file-nommu.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/ramfs/file-nommu.c b/fs/ramfs/file-nommu.c
index fbb0b478a346..d5378d028589 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);