From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7E23CC433B4 for ; Mon, 26 Apr 2021 19:52:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 57CA661185 for ; Mon, 26 Apr 2021 19:52:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241076AbhDZTxd (ORCPT ); Mon, 26 Apr 2021 15:53:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34826 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241606AbhDZTxd (ORCPT ); Mon, 26 Apr 2021 15:53:33 -0400 Received: from zeniv-ca.linux.org.uk (zeniv-ca.linux.org.uk [IPv6:2607:5300:60:148a::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 47A03C061574; Mon, 26 Apr 2021 12:52:51 -0700 (PDT) Received: from viro by zeniv-ca.linux.org.uk with local (Exim 4.94 #2 (Red Hat Linux)) id 1lb7Hl-008TqF-IE; Mon, 26 Apr 2021 19:52:49 +0000 Date: Mon, 26 Apr 2021 19:52:49 +0000 From: Al Viro To: David Howells Cc: linux-fsdevel@vger.kernel.org, Dave Wysochanski , Marc Dionne , "Matthew Wilcox (Oracle)" , Christoph Hellwig , linux-mm@kvack.org, linux-cachefs@redhat.com, linux-afs@lists.infradead.org, linux-nfs@vger.kernel.org, linux-cifs@vger.kernel.org, ceph-devel@vger.kernel.org, v9fs-developer@lists.sourceforge.net, Trond Myklebust , Anna Schumaker , Steve French , Dominique Martinet , Jeff Layton , linux-kernel@vger.kernel.org Subject: Re: [PATCH v7 01/31] iov_iter: Add ITER_XARRAY Message-ID: References: <161918446704.3145707.14418606303992174310.stgit@warthog.procyon.org.uk> <161918448151.3145707.11541538916600921083.stgit@warthog.procyon.org.uk> <3651951.1619465011@warthog.procyon.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3651951.1619465011@warthog.procyon.org.uk> Sender: Al Viro Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org On Mon, Apr 26, 2021 at 08:23:31PM +0100, David Howells wrote: > I really need to defer this question to Willy, but as I understand it, > xas_retry() only restarts the current iteration. Referring to the comment on > xas_reset(): > > * Resets the error or walk state of the @xas so future walks of the > * array will start from the root. Use this if you have dropped the > * xarray lock and want to reuse the xa_state. > > I think that the walk returns to the bottom of the tree and whilst xarray > presents an interface that appears to be a contiguous array, it's actually a > tree internally - and 'root' is the root of the tree, not the head of the > array. > > Basically, I think it throws away its cached iteration state - which might > have been modified - and rewalks the tree to get back to the same index. >From RTFS(lib/xarray.c) that looks right. Nevermind the question, then... Anyway, Reviewed-by: Al Viro on the xarray-related bits (this patch + followups)