From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40567) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YqLD9-0006AF-TC for qemu-devel@nongnu.org; Thu, 07 May 2015 08:47:32 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YqLD9-0002pF-5c for qemu-devel@nongnu.org; Thu, 07 May 2015 08:47:31 -0400 Message-ID: <554B5ED3.4030405@redhat.com> Date: Thu, 07 May 2015 14:47:15 +0200 From: Paolo Bonzini MIME-Version: 1.0 References: <1426791801-9042-1-git-send-email-mreitz@redhat.com> <20150505094606.GB29818@stefanha-thinkpad.redhat.com> <554A1160.7020200@redhat.com> <554A3395.7050509@redhat.com> <554A3D7B.3040603@redhat.com> <554A3F37.9080704@redhat.com> <554A4349.10301@redhat.com> <554A459B.1060505@redhat.com> <554A4E2D.4050300@redhat.com> <554B58A8.6000203@redhat.com> <20150507122911.GB4571@noname.redhat.com> In-Reply-To: <20150507122911.GB4571@noname.redhat.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Subject: Re: [Qemu-devel] [Qemu-block] [PATCH v2 0/3] block: Warn about usage of growing formats over non-growable protocols List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Kevin Wolf Cc: Stefan Hajnoczi , qemu-block@nongnu.org, qemu-devel@nongnu.org, Stefan Hajnoczi , Max Reitz On 07/05/2015 14:29, Kevin Wolf wrote: > > No, it shouldn't indeed. > > > > Could alloc_clusters_noref do bdrv_truncate and return ENOSPC if it > > fails? That's how for example qcow and vhdx work. vdi has the same > > problem. > > If you want NBD to return -ENOSPC for writes after EOF, change the > nbd block driver to do just that. There's no reason to add additional > overhead to qcow2 (even over raw-posix) for that. Does ENOSPC over LVM (dm-linear) work at all, and who generates the ENOSPC there? Paolo