From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753926AbaJ0TFY (ORCPT ); Mon, 27 Oct 2014 15:05:24 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:52939 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753906AbaJ0TFT (ORCPT ); Mon, 27 Oct 2014 15:05:19 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Mikulas Patocka , Al Viro , Kamal Mostafa Subject: [PATCH 3.13 085/105] fs: make cont_expand_zero interruptible Date: Mon, 27 Oct 2014 11:57:00 -0700 Message-Id: <1414436240-13879-86-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1414436240-13879-1-git-send-email-kamal@canonical.com> References: <1414436240-13879-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.13 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.13.11.10 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Mikulas Patocka commit c2ca0fcd202863b14bd041a7fece2e789926c225 upstream. This patch makes it possible to kill a process looping in cont_expand_zero. A process may spend a lot of time in this function, so it is desirable to be able to kill it. It happened to me that I wanted to copy a piece data from the disk to a file. By mistake, I used the "seek" parameter to dd instead of "skip". Due to the "seek" parameter, dd attempted to extend the file and became stuck doing so - the only possibility was to reset the machine or wait many hours until the filesystem runs out of space and cont_expand_zero fails. We need this patch to be able to terminate the process. Signed-off-by: Mikulas Patocka Signed-off-by: Al Viro Signed-off-by: Kamal Mostafa --- fs/buffer.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/buffer.c b/fs/buffer.c index be90719..4252d82 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -2313,6 +2313,11 @@ static int cont_expand_zero(struct file *file, struct address_space *mapping, err = 0; balance_dirty_pages_ratelimited(mapping); + + if (unlikely(fatal_signal_pending(current))) { + err = -EINTR; + goto out; + } } /* page covers the boundary, find the boundary offset */ -- 1.9.1