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

From: Larry McVoy
Date: Mon May 17 2004 - 10:22:27 EST


On Mon, May 17, 2004 at 11:17:38AM -0400, Theodore Ts'o wrote:
> On Mon, May 17, 2004 at 08:56:40AM -0500, Wayne Scott wrote:
> > From: Andrew Morton <akpm@xxxxxxxx>
> > > 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.

That's news to me. And we use fwrite.
--
---
Larry McVoy lm at bitmover.com http://www.bitkeeper.com
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/