From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lukas Czerner Subject: Re: [PATCH 4/7] xfs: Implement fallocate query support mode Date: Tue, 19 Sep 2017 10:15:38 +0200 Message-ID: <20170919081538.mk23eue6dysv67b2@rh_laptop> References: <1505749947-26360-1-git-send-email-lczerner@redhat.com> <1505749947-26360-5-git-send-email-lczerner@redhat.com> <20170918175651.GA7937@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20170918175651.GA7937@infradead.org> Sender: linux-fsdevel-owner@vger.kernel.org To: Christoph Hellwig Cc: linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-api@vger.kernel.org List-Id: linux-api@vger.kernel.org On Mon, Sep 18, 2017 at 10:56:51AM -0700, Christoph Hellwig wrote: > This seems to miss any explanation and 6 out of 7 patches. See linux-fsdevel for entire patch set. https://www.spinics.net/lists/linux-fsdevel/msg115740.html > > That being said, I really detest adding weird query modes to random > syscalls. We should expose capabilities through the interface that > was designed for such things: (f)pathconf, as there are a lot more > important parameters we currently fail to expose to userspace to > start with. (f)pathconf on it's own is useless because I need to get this information directly from the file system. Supported fallocate modes can differ with inode flags (encrypted files, extent/indirect based files on ext4). I also need in-kernel interface. That's why I though fallocate is the convenient place to put this. I have not looked to it, but other option might be to use fstat to get this. -Lukas