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=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 3E5F0C4363D for ; Fri, 25 Sep 2020 04:17:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E4A6A2085B for ; Fri, 25 Sep 2020 04:17:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="w9qQAV+u" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726925AbgIYERj (ORCPT ); Fri, 25 Sep 2020 00:17:39 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:47726 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726758AbgIYERj (ORCPT ); Fri, 25 Sep 2020 00:17:39 -0400 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 08P4GXlC189604; Fri, 25 Sep 2020 04:17:34 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=subject : to : cc : references : from : message-id : date : mime-version : in-reply-to : content-type : content-transfer-encoding; s=corp-2020-01-29; bh=V+jb8mf+feV/R4tp711eSIHV8HypUcIu9cLItDM6cX8=; b=w9qQAV+uWO7qyw7hPfRGV3fCdxb+6y1bZSWxNgezoUwmWZfONDYsPRUGMOlLUJLF1YKT t0RuzcuCRhKXtI1oDnsp+7wZSm/mPF+/uPMjqIQmYfmVVZ+swTrk5cfe9FfUnX8XjDBc oTc/9pCSbEYqhyd1s0Q6HLlh0ahOtiCA0w+Q8Pi2VnMB9Q4Mjr2346NqThwXE0rBhOQi xJRzN1NASzODliNwejQ5eDt4Ardtrs5rOLojYFiWLfB4yn9sEEVSsjjiQwkjHczf9k/c /iRxYhJtBra0MkcN4kWsFQBQULv5UWqNwz+MbU9FoEfwUab9qUI292Jk3T37fOxnBhl+ tg== Received: from aserp3030.oracle.com (aserp3030.oracle.com [141.146.126.71]) by aserp2120.oracle.com with ESMTP id 33q5rgsw3x-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Fri, 25 Sep 2020 04:17:34 +0000 Received: from pps.filterd (aserp3030.oracle.com [127.0.0.1]) by aserp3030.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 08P4ASb6126919; Fri, 25 Sep 2020 04:17:34 GMT Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by aserp3030.oracle.com with ESMTP id 33s75jb9bk-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 25 Sep 2020 04:17:34 +0000 Received: from abhmp0016.oracle.com (abhmp0016.oracle.com [141.146.116.22]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 08P4HXGM009601; Fri, 25 Sep 2020 04:17:33 GMT Received: from [192.168.1.102] (/39.109.231.106) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 24 Sep 2020 21:17:32 -0700 Subject: Re: [PATCH 1/2] btrfs: drop never met condition of disk_total_bytes == 0 To: Nikolay Borisov , linux-btrfs@vger.kernel.org Cc: wqu@suse.com, dsterba@suse.com References: <4fea8a706aedf7407d6af7a545126511168e15f5.1600940809.git.anand.jain@oracle.com> From: Anand Jain Message-ID: Date: Fri, 25 Sep 2020 12:17:27 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.2.2 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9754 signatures=668680 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxlogscore=999 bulkscore=0 malwarescore=0 adultscore=0 phishscore=0 spamscore=0 mlxscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2009250028 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9754 signatures=668680 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 impostorscore=0 clxscore=1015 suspectscore=0 phishscore=0 malwarescore=0 priorityscore=1501 mlxlogscore=999 adultscore=0 bulkscore=0 mlxscore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2009250028 Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On 24/9/20 7:48 pm, Nikolay Borisov wrote: > > > On 24.09.20 г. 13:11 ч., Anand Jain wrote: >> btrfs_device::disk_total_bytes is set even for a seed device (the >> comment is wrong). >> >> The function fill_device_from_item() does the job of reading it from the >> item and updating btrfs_device::disk_total_bytes. So both the missing >> device and the seed devices do have their disk_total_bytes updated. >> >> So this patch removes the check dev->disk_total_bytes == 0 in the >> function verify_one_dev_extent() >> >> Signed-off-by: Anand Jain >> --- >> fs/btrfs/volumes.c | 15 --------------- >> 1 file changed, 15 deletions(-) >> >> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c >> index 7f43ed88fffc..9be40eece8ed 100644 >> --- a/fs/btrfs/volumes.c >> +++ b/fs/btrfs/volumes.c >> @@ -7578,21 +7578,6 @@ static int verify_one_dev_extent(struct btrfs_fs_info *fs_info, >> goto out; >> } >> >> - /* It's possible this device is a dummy for seed device */ >> - if (dev->disk_total_bytes == 0) { >> - struct btrfs_fs_devices *devs; >> - >> - devs = list_first_entry(&fs_info->fs_devices->seed_list, >> - struct btrfs_fs_devices, seed_list); >> - dev = btrfs_find_device(devs, devid, NULL, NULL, false); >> - if (!dev) { >> - btrfs_err(fs_info, "failed to find seed devid %llu", >> - devid); >> - ret = -EUCLEAN; >> - goto out; >> - } >> - } > > The commit which introduced this check states that the device with a > disk_total_bytes = 0 occurs from clone_fs_devices called from open_seed. > It seems the check is legit and your changelog doesn't account for that > if it's safe you should provide description why is that. yes the commit 1b3922a8bc74 (btrfs: Use real device structure to verify dev extent) introduced it. In Qu's analysis, it is unclear why the total_disk_bytes was 0. Theoretically, all devices (including missing and seed) marked with the BTRFS_DEV_STATE_IN_FS_METADATA flag gets the total_disk_bytes updated at fill_device_from_item(). open_ctree() btrfs_read_chunk_tree() read_one_dev() open_seed_device() fill_device_from_item() Even if verify_one_dev_extent() reports total_disk_bytes == 0, then IMO its a bug to be fixed somewhere else and not in verify_one_dev_extent() as it's just a messenger. It is never expected that a total_disk_bytes shall be zero. So it is fine to drop the total_disk_bytes == 0 check. Thanks, Anand > >> - >> if (physical_offset + physical_len > dev->disk_total_bytes) { >> btrfs_err(fs_info, >> "dev extent devid %llu physical offset %llu len %llu is beyond device boundary %llu", >>