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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no 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 7BB32C388F9 for ; Wed, 11 Nov 2020 14:40:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3389F2067D for ; Wed, 11 Nov 2020 14:40:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726958AbgKKOkO (ORCPT ); Wed, 11 Nov 2020 09:40:14 -0500 Received: from imap2.colo.codethink.co.uk ([78.40.148.184]:59098 "EHLO imap2.colo.codethink.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727307AbgKKOkL (ORCPT ); Wed, 11 Nov 2020 09:40:11 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126] helo=xylophone) by imap2.colo.codethink.co.uk with esmtpsa (Exim 4.92 #3 (Debian)) id 1kcrHb-0003fe-DW; Wed, 11 Nov 2020 14:39:35 +0000 Message-ID: Subject: Re: [PATCH 4.19 19/71] btrfs: extent_io: add proper error handling to lock_extent_buffer_for_io() From: Ben Hutchings To: Pavel Machek , Greg Kroah-Hartman Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, Qu Wenruo , David Sterba Date: Wed, 11 Nov 2020 14:39:34 +0000 In-Reply-To: <20201111124448.GA26508@amd> References: <20201109125019.906191744@linuxfoundation.org> <20201109125020.811120362@linuxfoundation.org> <20201111124448.GA26508@amd> Organization: Codethink Ltd. Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.30.5-1.1 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2020-11-11 at 13:44 +0100, Pavel Machek wrote: > Hi! > > > Thankfully it's handled by the only caller, btree_write_cache_pages(), > > as later write_one_eb() call will trigger submit_one_bio(). So there > > shouldn't be any problem. > > This explains there should not be any problem in _the > mainline_. AFAICT this talks about this code. Mainline version is: > > prev_eb = eb; > ret = lock_extent_buffer_for_io(eb, &epd); > if (!ret) { > free_extent_buffer(eb); > continue; > } else if (ret < 0) { > done = 1; > free_extent_buffer(eb); > break; > } > > But 4.19 has: > > ret = lock_extent_buffer_for_io(eb, fs_info, &epd); > if (!ret) { > free_extent_buffer(eb); > continue; > } That was changed in mainline two releases after this commit, though. > IOW missing the code mentioned in the changelog. Is 0607eb1d452d4 > prerequisite for this patch? I think it's a separate fix, but probably worth picking too. Ben. > Best regards, > Pavel > > > +/* > > + * Lock eb pages and flush the bio if we can't the locks > > + * > > + * Return 0 if nothing went wrong > > + * Return >0 is same as 0, except bio is not submitted > > + * Return <0 if something went wrong, no page is locked > > + */ -- Ben Hutchings, Software Developer Codethink Ltd https://www.codethink.co.uk/ Dale House, 35 Dale Street Manchester, M1 2HF, United Kingdom