Re: Kernel Compile in tmpfs crumples in 2.4.12 w/epoll patch

Alexander Viro (viro@math.psu.edu)
Mon, 22 Oct 2001 13:29:33 -0400 (EDT)


On Mon, 22 Oct 2001, Larry McVoy wrote:

> for (;;) {
> lstat(dir);
> while (e = readdir(..)) save(e->d_name);
> lstat(dir)
> if (dir size && dir mtime have NOT changed) break;
> cleanup the array and go start over
> }
> sort entries
> return sorted list
>
> The basic idea being that we first of all narrow the race window and
> second of all detect the race in all cases where the mods to the dir
> result in either a changed mtime or a changed size. So yes, that leaves
> us open to cases where the size didn't change but the contents did but
> I'll be ding danged if I can see a way around that.

There's none. Notice that if you want a coherent view of directory,
you need something like the variant above anyway - even with FFS. New
entry could've been added into slack in one of the entries you've
already seen.

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/