From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wu Fengguang Subject: Re: [PATCH 2/2] fs: Make write(2) interruptible by a signal Date: Wed, 16 Nov 2011 19:44:21 +0800 Message-ID: <20111116114421.GA9098@localhost> References: <1321441935-6802-1-git-send-email-jack@suse.cz> <1321441935-6802-3-git-send-email-jack@suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Andrew Morton , Christoph Hellwig , Al Viro , "linux-fsdevel@vger.kernel.org" To: Jan Kara Return-path: Received: from mga03.intel.com ([143.182.124.21]:25382 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756087Ab1KPLoZ (ORCPT ); Wed, 16 Nov 2011 06:44:25 -0500 Content-Disposition: inline In-Reply-To: <1321441935-6802-3-git-send-email-jack@suse.cz> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Jan, Due to the (very low) possibility of data loss by partial writes, IMHO it would safer to test this patch in linux-next until next merge window, would you agree? Pushing the first patch will address the main problem, anyway. Thanks, Fengguang On Wed, Nov 16, 2011 at 07:12:15PM +0800, Jan Kara wrote: > Currently write(2) to a file is not interruptible by a signal. Sometimes this > is desirable (e.g. when you want to quickly kill a process hogging your disk or > when some process gets blocked in balance_dirty_pages() indefinitely due to a > filesystem being in an error condition). > > Reported-by: Kazuya Mio > Tested-by: Kazuya Mio > Signed-off-by: Jan Kara > --- > mm/filemap.c | 6 ++++-- > 1 files changed, 4 insertions(+), 2 deletions(-) > > diff --git a/mm/filemap.c b/mm/filemap.c > index c0018f2..c106d3b 100644 > --- a/mm/filemap.c > +++ b/mm/filemap.c > @@ -2407,7 +2407,6 @@ static ssize_t generic_perform_write(struct file *file, > iov_iter_count(i)); > > again: > - > /* > * Bring in the user page that we will copy from _first_. > * Otherwise there's a nasty deadlock on copying from the > @@ -2463,7 +2462,10 @@ again: > written += copied; > > balance_dirty_pages_ratelimited(mapping); > - > + if (fatal_signal_pending(current)) { > + status = -EINTR; > + break; > + } > } while (iov_iter_count(i)); > > return written ? written : status; > -- > 1.7.1