From: Andreas Dilger Subject: Re: [PATCH 1/6] fs: add hole punching to fallocate Date: Tue, 16 Nov 2010 18:22:47 -0600 Message-ID: <18ACAA85-8847-4B12-9839-F99FB6C7B3E4@dilger.ca> 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> <20101116125249.GB31957@dhcp231-156.rdu.redhat.com> <20101116131451.GH4757@quack.suse.cz> Mime-Version: 1.0 (Apple Message framework v1081) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8BIT 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: In-Reply-To: <20101116131451.GH4757@quack.suse.cz> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On 2010-11-16, at 07:14, Jan Kara wrote: >> 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. > > So we call it "mode" but speak about "flags"? Seems a bit inconsistent. > I'd maybe lean a bit at the "flags" side and just make sure that only one of FALLOC_FL_KEEP_SIZE, FALLOC_FL_PUNCH_HOLE is set (interpreting FALLOC_FL_KEEP_SIZE as allocate blocks beyond i_size). But I'm not sure what others think. IMHO, it makes more sense for consistency and "get what users expect" that these be treated as flags. Some users will want KEEP_SIZE, but in other cases it may make sense that a hole punch at the end of a file should shrink the file (i.e. the opposite of an append). Cheers, Andreas