From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mr001msb.fastweb.it ([85.18.95.85]:50866 "EHLO mr001msb.fastweb.it" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751642AbdFJWAM (ORCPT ); Sat, 10 Jun 2017 18:00:12 -0400 Subject: Re: It is safe to execute a fallocate on a opened and in-use =?UTF-8?Q?=20file=3F?= MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Sun, 11 Jun 2017 00:00:06 +0200 From: Gionatan Danti In-Reply-To: <20170610211822.GN4530@birch.djwong.org> References: <85e83dbc8f31ecd79e018d595aa2e491@assyoma.it> <20170610211822.GN4530@birch.djwong.org> Message-ID: Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: "Darrick J. Wong" Cc: linux-xfs@vger.kernel.org, g.danti@assyoma.it Il 10-06-2017 23:18 Darrick J. Wong ha scritto: > > Yes, writes and fallocates are serialized with each other to avoid > corruption. > Great. Is this behavior valid for all filesystem (ie: it is implemented on the VFS layer) or is it filesystem-specific? > > How do you get qemu to announce the disk size change the guest? > You can do that via virsh blockresize which, in turn, taps on qemu monitor (which can even be used directly, without libvirt intervention). From virsh man page: "blockresize domain path size Resize a block device of domain while the domain is running, path specifies the absolute path of the block device; it corresponds to a unique target name () or source file () for one of the disk devices attached to domain (see also domblklist for listing these names)." Thanks. > --D > >> In general, how to consider concurrent metadata updates for the same >> file/block? Should I expect file corruption, similar to concurrently >> writing >> data to the same file/block? >> >> Thanks. >> >> -- >> Danti Gionatan >> Supporto Tecnico >> Assyoma S.r.l. - www.assyoma.it >> email: g.danti@assyoma.it - info@assyoma.it >> GPG public key ID: FF5F32A8 >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-xfs" >> in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html -- Danti Gionatan Supporto Tecnico Assyoma S.r.l. - www.assyoma.it email: g.danti@assyoma.it - info@assyoma.it GPG public key ID: FF5F32A8