Re: [RFC][PATCH 10/13] make dump_emit() use vfs_write() instead ofbanging at ->f_op->write directly

[Linus Torvalds]

On Tue, Oct 8, 2013 at 5:15 PM, Al Viro <viro@xxxxxxxxxxxxxxxx> wrote:
>
> ... and deal with short writes properly

.. except you don't.

> +       while (nr) {
> +               if (dump_interrupted())
> +                       return 0;
> +               n = vfs_write(file, addr, nr, &pos);
> +               if (n < 0)
> +                       return 0;
> +               file->f_pos = pos;
> +               cprm->written += n;
> +               nr -= n;
> +       }

Please handle 'n == 0' too. Maybe it never happens (ie you get EPIPE
or ENOSPC), but write returning zero is actually possible and a valid
return value and traditional for "end of media". Looping forever is
not a good idea.

               Linus
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