Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752349AbcCXPIo (ORCPT ); Thu, 24 Mar 2016 11:08:44 -0400 Received: from smtp2.provo.novell.com ([137.65.250.81]:44752 "EHLO smtp2.provo.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750901AbcCXPI1 (ORCPT ); Thu, 24 Mar 2016 11:08:27 -0400 Date: Thu, 24 Mar 2016 16:08:18 +0100 From: Petr Tesarik To: David Sterba Cc: Flex Liu , David Sterba , linux-btrfs@vger.kernel.org, Chris Mason , Josef Bacik , linux-kernel@vger.kernel.org, Flex Liu Subject: Re: [PATCH 1/1] Btrfs: Code Cleanup Message-ID: <20160324160818.57850176@hananiah.suse.cz> In-Reply-To: <20160324150307.GR29764@twin.jikos.cz> References: <1458457871-25512-1-git-send-email-fliu@novell.com> <20160324150307.GR29764@twin.jikos.cz> Organization: SUSE Linux X-Mailer: Claws Mail 3.11.0 (GTK+ 2.24.28; x86_64-suse-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1051 Lines: 29 On Thu, 24 Mar 2016 16:03:07 +0100 David Sterba wrote: > On Sun, Mar 20, 2016 at 03:11:11PM +0800, Flex Liu wrote: >[...] > > --- a/fs/btrfs/volumes.c > > +++ b/fs/btrfs/volumes.c > > @@ -2325,7 +2325,10 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path) > > if (seeding_dev) { > > sb->s_flags &= ~MS_RDONLY; > > ret = btrfs_prepare_sprout(root); > > - BUG_ON(ret); /* -ENOMEM */ > > + if (ret) { > > + btrfs_abort_transaction(trans, root, ret); > > The transaction abort seems a bit heavy as it will take down the whole > filesystem. It's called from the device add ioctl, this is a restartable > operation. > > Unfortunatelly btrfs_prepare_sprout is called after the transaction > start so btrfs_abort_transaction must be called. To avoid it, the code > would need to be reorganized, so the memory allocations happen in > advance. On the other hand, an abort is still better than a BUG_ON(), and it may be easier to make incremental improvements. Just my 2 cents (I haven't tried it), Petr T