From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from verein.lst.de ([213.95.11.211]:33395 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726274AbfFYKHc (ORCPT ); Tue, 25 Jun 2019 06:07:32 -0400 Date: Tue, 25 Jun 2019 12:07:01 +0200 From: Christoph Hellwig Subject: Re: [PATCH 04/12] xfs: initialize ioma->flags in xfs_bmbt_to_iomap Message-ID: <20190625100701.GG1462@lst.de> References: <20190624055253.31183-1-hch@lst.de> <20190624055253.31183-5-hch@lst.de> <20190624145707.GH5387@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190624145707.GH5387@magnolia> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: "Darrick J. Wong" Cc: Christoph Hellwig , Damien Le Moal , Andreas Gruenbacher , linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org On Mon, Jun 24, 2019 at 07:57:07AM -0700, Darrick J. Wong wrote: > On Mon, Jun 24, 2019 at 07:52:45AM +0200, Christoph Hellwig wrote: > > Currently we don't overwrite the flags field in the iomap in > > xfs_bmbt_to_iomap. This works fine with 0-initialized iomaps on stack, > > but is harmful once we want to be able to reuse an iomap in the > > writeback code. > > Is that going to affect all the other iomap users, or is xfs the only > one that assumes zero-initialized iomaps being passed into > ->iomap_begin? This doesn't affect any existing user as they all get a zeroed iomap passed from the caller in iomap.c. It affects the writeback code once it uses struct iomap as it overwrites a previously used iomap.