Re: 1352 NUL bytes at the end of a page?

Theodore Ts'o
2004-05-17T15:18:20Z

On Mon, May 17, 2004 at 08:56:40AM -0500, Wayne Scott wrote:
> From: Andrew Morton <akpm@osdl.org>
> > Well we can stop right there, because the only way someone can get some
> > more non-zero user data into this page before we memset and write it is by
> > locking the page beforehand, and block_write_full_page() has the page lock.
> > (Or they can write stuff into it via mmap, but writing to the page outside
> > i_size is an application bug).
>
> BTW: BitKeeper never opens a writable mmap to a file. The files are
> read with mmap() and written by fwriting to a tmp file and then
> renaming over the target. And since we run on Windows, no process has
> the file open when we are updating it.

Note though that the stdio library uses a writeable mmap to implement
fwrite.

- Ted