| Message ID | 1323235287-29806-2-git-send-email-xiaoqiangnk@gmail.com |
|---|---|
| State | Accepted, archived |
| Headers | show |
On Wed, Dec 07, 2011 at 01:21:27PM +0800, Yongqiang Yang wrote: > We need to zero out part of a page which beyond EOF before setting uptodate, > otherwise, mapread or write will see non-zero data beyond EOF. > > Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com> Thanks, applied. - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c index 235b79d..9e145b8 100644 --- a/fs/ext4/page-io.c +++ b/fs/ext4/page-io.c @@ -385,6 +385,18 @@ int ext4_bio_write_page(struct ext4_io_submit *io, block_end = block_start + blocksize; if (block_start >= len) { + /* + * Comments copied from block_write_full_page_endio: + * + * The page straddles i_size. It must be zeroed out on + * each and every writepage invocation because it may + * be mmapped. "A file is mapped in multiples of the + * page size. For a file that is not a multiple of + * the page size, the remaining memory is zeroed when + * mapped, and writes to that region are not written + * out to the file." + */ + zero_user_segment(page, block_start, block_end); clear_buffer_dirty(bh); set_buffer_uptodate(bh); continue;
We need to zero out part of a page which beyond EOF before setting uptodate, otherwise, mapread or write will see non-zero data beyond EOF. Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com> --- fs/ext4/page-io.c | 12 ++++++++++++ 1 files changed, 12 insertions(+), 0 deletions(-)