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From: Linus Torvalds <torvalds@linux-foundation.org>
To: Al Viro <viro@ftp.linux.org.uk>
Cc: linux-fsdevel <linux-fsdevel@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [RFC][PATCH 10/13] make dump_emit() use vfs_write() instead of banging at ->f_op->write directly
Date: Tue, 8 Oct 2013 17:52:42 -0700	[thread overview]
Message-ID: <CA+55aFxvNhuXoux88tcYemMWe5Nxdc-srfj3YgBZ7LJ-JaBEdQ@mail.gmail.com> (raw)
In-Reply-To: <E1VThRL-0002yt-ON@ZenIV.linux.org.uk>

On Tue, Oct 8, 2013 at 5:15 PM, Al Viro <viro@ftp.linux.org.uk> 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

  reply	other threads:[~2013-10-09  0:52 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-10-09  0:15 [RFC][PATCH 10/13] make dump_emit() use vfs_write() instead of banging at ->f_op->write directly Al Viro
2013-10-09  0:52 ` Linus Torvalds [this message]
2013-10-09  1:18   ` Al Viro
2013-10-09  1:20     ` Al Viro
2013-10-09  1:38     ` Linus Torvalds
2013-10-09  2:06       ` Al Viro
2013-10-09  2:27         ` Linus Torvalds

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