From: Jan Kara Subject: Re: [PATCH 1/6] fs: add hole punching to fallocate Date: Tue, 16 Nov 2010 12:43:46 +0100 Message-ID: <20101116114346.GB4757@quack.suse.cz> References: <1289840723-3056-1-git-send-email-josef@redhat.com> <1289840723-3056-2-git-send-email-josef@redhat.com> <20101116111611.GA4757@quack.suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: 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: Josef Bacik Return-path: Received: from cantor.suse.de ([195.135.220.2]:49204 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933630Ab0KPLns (ORCPT ); Tue, 16 Nov 2010 06:43:48 -0500 Content-Disposition: inline In-Reply-To: <20101116111611.GA4757@quack.suse.cz> Sender: linux-ext4-owner@vger.kernel.org List-ID: 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... Honza -- Jan Kara SUSE Labs, CR