From: Josef Bacik Subject: Re: [PATCH 1/6] fs: add hole punching to fallocate Date: Tue, 16 Nov 2010 07:52:50 -0500 Message-ID: <20101116125249.GB31957@dhcp231-156.rdu.redhat.com> References: <1289840723-3056-1-git-send-email-josef@redhat.com> <1289840723-3056-2-git-send-email-josef@redhat.com> <20101116111611.GA4757@quack.suse.cz> <20101116114346.GB4757@quack.suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Josef Bacik , david@fromorbit.com, linux-kernel@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, xfs@oss.sgi.com, cmm@us.ibm.com, cluster-devel@redhat.com, ocfs2-devel@oss.oracle.com To: Jan Kara Return-path: Received: from mx1.redhat.com ([209.132.183.28]:18818 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756202Ab0KPMxg (ORCPT ); Tue, 16 Nov 2010 07:53:36 -0500 Content-Disposition: inline In-Reply-To: <20101116114346.GB4757@quack.suse.cz> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Tue, Nov 16, 2010 at 12:43:46PM +0100, Jan Kara wrote: > On Tue 16-11-10 12:16:11, Jan Kara wrote: > > On Mon 15-11-10 12:05:18, Josef Bacik wrote: > > > diff --git a/fs/open.c b/fs/open.c > > > index 4197b9e..ab8dedf 100644 > > > --- a/fs/open.c > > > +++ b/fs/open.c > > > @@ -223,7 +223,7 @@ int do_fallocate(struct file *file, int mode, loff_t offset, loff_t len) > > > return -EINVAL; > > > > > > /* Return error if mode is not supported */ > > > - if (mode && !(mode & FALLOC_FL_KEEP_SIZE)) > > > + if (mode && (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))) > > Why not just: > > if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE)) ? > And BTW, since FALLOC_FL_PUNCH_HOLE does not change the file size, should > not we enforce that FALLOC_FL_KEEP_SIZE is / is not set? I don't mind too > much which way but keeping it ambiguous (ignored) in the interface usually > proves as a bad idea in future when we want to further extend the interface... > Yeah I went back and forth on this. KEEP_SIZE won't change the behavior of PUNCH_HOLE since PUNCH_HOLE implicitly means keep the size. I figured since its "mode" and not "flags" it would be ok to make either way accepted, but if you prefer PUNCH_HOLE means you have to have KEEP_SIZE set then I'm cool with that, just let me know one way or the other. Thanks, Josef