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

Larry McVoy
2004-05-17T15:21:08Z

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@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.

That's news to me. And we use fwrite.
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Larry McVoy lm at bitmover.com http://www.bitkeeper.com