Re: 1352 NUL bytes at the end of a page? (was Re: Assertion `s && s->tree' failed: The saga continues.)

[Larry McVoy]

On Mon, May 17, 2004 at 12:25:06AM -0700, Andrew Morton wrote:
> Linus Torvalds <torvalds@xxxxxxxx> wrote:
> >
> > Andrew, the obvious culprit would be the memset() in fs/buffer.c 
> >  (block_write_full_page() 
> 
> There is one race.
> 
> If an application does mmap(MAP_SHARED) of, say, a 2048 byte file and then
> extends it:
> 
> 	p = mmap(..., fd, ...);
> 	ftructate(fd, 4096);
> 	p[3000] = 1;
> 
> A racing block_write_full_page() could fail to notice the extended i_size
> and would decide to zap those 2048 bytes anyway.	

This isn't our problem, we only read with mmap().  We write with stdio.
-- 
---
Larry McVoy                lm at bitmover.com           http://www.bitkeeper.com
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