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=-1.0 required=3.0 tests=FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 1CAAAC43387 for ; Wed, 2 Jan 2019 23:46:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C2A832075B for ; Wed, 2 Jan 2019 23:46:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728003AbfABXqk (ORCPT ); Wed, 2 Jan 2019 18:46:40 -0500 Received: from mout.gmx.net ([212.227.17.20]:34593 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726078AbfABXqj (ORCPT ); Wed, 2 Jan 2019 18:46:39 -0500 Received: from Damenlys-MBP.lan ([180.111.171.105]) by mail.gmx.com (mrgmx102 [212.227.17.174]) with ESMTPSA (Nemesis) id 0M82zV-1hZqc9263F-00vhDh; Thu, 03 Jan 2019 00:46:29 +0100 Subject: Re: [PATCH 3/3] btrfs-progs: Create uuid tree with proper contents To: dsterba@suse.cz, Qu Wenruo , linux-btrfs@vger.kernel.org References: <20181227071333.10964-1-wqu@suse.com> <20181227071333.10964-4-wqu@suse.com> <48804351-b8b3-b876-529a-807d05259664@gmx.com> <20190102163128.GY23615@twin.jikos.cz> From: Su Yue Message-ID: Date: Thu, 3 Jan 2019 07:46:24 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:64.0) Gecko/20100101 Thunderbird/64.0 MIME-Version: 1.0 In-Reply-To: <20190102163128.GY23615@twin.jikos.cz> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Provags-ID: V03:K1:r0WbHIXkOqyan49vsiufmAC1l9KicHAk8DqbBLViJbP9yERt8yQ ntLqDMt9IrCL15Ch0CqUYVodIf5f0bsqeTg8UWxM557eT4AxKrV/VuBU2QqHEuScx5gVOz1 lERMrhv5ZiqJIJ5UZg+gKMsGPT3UaGr79oOpABm7zFTjR67vPjoUO8O4mJFP3Wvocdej4sA jMU2LaBD7FvvLcKN9pQUQ== X-UI-Out-Filterresults: notjunk:1;V03:K0:bVUvIWZRzt4=:egWwuR0MkFAXDPpelP6+6E I2RFDOpp5+u3cIgnkdIJudJ5B0gIL1+4JSsHdn51kkYQi83n/i9RQdFG2RLaICwKtOT9q1Veb ldvtfGsNVeu+JuS5vaRwczMRK9BbBUAcRHEJyv1fDKb21ms5hDKrJ+FV05pJ8pb5I1QzwQMhx f0JIpf3mVy1w+JdvezL8AXt/xggBC341qYaZtnRCX74HHC6ry8rso9JUxZ7xClztoScRuDWDM meGNPOyaHx9VFWkmrZzoQcFbnufEyeQXetRDN4adKKNV7t3DBPaZfBIUVGS6jdVs5EG/kV+In 4LvC9wND81hJfeGdXudifxB434Tv78b8yMWUIqM8raMBOvQHMTDd7SCTfRqgy05nmm9M13IHz P/CquJrPqwZO2cWIsLyo09irr5hOvyB9KU7s3IYXK80dqPL1BrlokQhZ0L+CEd8U5W7XEupwy iV40R2ac1sa6ECHrQ/bpVvtp7coRZtf7Mn93MDolvYfvE7nq9wgXmV584qA5SwpSlWO5emj0o VLCDu7pBA9oQeDw5+cvkf5SMrxhDdNeCRS8tIdKilW5R/UUVFbgpyMXPK/CFP+frOiwHSUTy+ OtxB+sLXs7JTTK7bXkZ4CRLTMkpEI1RL4OWZq8y0VBdRu+bpKlyxWpK5egwhkORaZczjl3z4p A6TVFqZwdh0KBgyeBeWDKyCsxcE8D/4OtvSQORJnpQuq+QOrL7OSMezMY4J47qx4aKjr6nhsx L6809Tr5v9qLexASePErdn15jz6MfKVL/AkkImLKwZ1tS6TZimPNiKwvgInPMlUSwhseTa9wm qnmYnI1bs4nXMwn0dMeglzZemDMsNmRBK1pXkM4ojrVM5kLogh0EgTW04nLIGUxr+jlFVVHUb kmNsn/QE7rwgXMj6//F1kX0Vi9uWhszxYVU1sVQHp61NKCX3S3bHvGyc7ATPx8 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On 2019/1/3 12:31 AM, David Sterba wrote: > On Thu, Dec 27, 2018 at 07:28:40PM +0800, Su Yue wrote: >>> +} >>> + >>> +int create_uuid_tree(struct btrfs_trans_handle *trans) >>> +{ >>> + struct btrfs_fs_info *fs_info = trans->fs_info; >>> + struct btrfs_root *uuid_root = fs_info->uuid_root; >>> + struct btrfs_key key; >>> + int ret; >>> + >>> + if (!uuid_root) { >>> + ret = create_empty_tree(trans, BTRFS_UUID_TREE_OBJECTID); >>> + if (ret < 0) { >>> + errno = -ret; >>> + error("failed to create uuid root: %m"); >> >> In personal taste, I don't like such assignment. >> Let the community say. > > Check eg. 251d32ea5cd1cf74cb52, replaces strerror(errno) with %m and > requires no change. As we're using strerror(-ret) in many places, it's a > followup that needs the extra errno assignment. This is IMO a small cost > on the source code size and the gain in space savings might be > noticeable for embedded devices, but we need to do all the conversions. > Got it, Thanks.