From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761251AbbA1ERv (ORCPT ); Tue, 27 Jan 2015 23:17:51 -0500 Received: from mail.kernel.org ([198.145.29.136]:38225 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761161AbbA1ERs (ORCPT ); Tue, 27 Jan 2015 23:17:48 -0500 From: lizf@kernel.org To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Mikulas Patocka , Al Viro , Zefan Li Subject: [PATCH 3.4 046/177] fs: make cont_expand_zero interruptible Date: Wed, 28 Jan 2015 12:07:39 +0800 Message-Id: <1422418236-12852-92-git-send-email-lizf@kernel.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1422418050-12581-1-git-send-email-lizf@kernel.org> References: <1422418050-12581-1-git-send-email-lizf@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Mikulas Patocka 3.4.106-rc1 review patch. If anyone has any objections, please let me know. ------------------ 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: Zefan Li --- fs/buffer.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/buffer.c b/fs/buffer.c index f235e18..104425b 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -2221,6 +2221,11 @@ 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