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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 4B319C4740A for ; Mon, 9 Sep 2019 14:34:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1EB7120863 for ; Mon, 9 Sep 2019 14:34:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727490AbfIIOeN (ORCPT ); Mon, 9 Sep 2019 10:34:13 -0400 Received: from mx2.suse.de ([195.135.220.15]:40332 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727112AbfIIOeM (ORCPT ); Mon, 9 Sep 2019 10:34:12 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 6FEC7ABBE; Mon, 9 Sep 2019 14:34:10 +0000 (UTC) Subject: Re: [PATCH v2 2/6] btrfs-progs: check/common: Introduce a function to find imode using INODE_REF To: Qu Wenruo , WenRuo Qu , linux-btrfs@vger.kernel.org References: <20190905075800.1633-1-wqu@suse.com> <20190905075800.1633-3-wqu@suse.com> <4e7099d2-5b4c-1fa3-ffdf-2b3332ed0b88@suse.com> <37228196-3617-e253-6ad1-125e72e6628c@gmx.com> Cc: David Sterba From: Nikolay Borisov Openpgp: preference=signencrypt Autocrypt: addr=nborisov@suse.com; prefer-encrypt=mutual; keydata= mQINBFiKBz4BEADNHZmqwhuN6EAzXj9SpPpH/nSSP8YgfwoOqwrP+JR4pIqRK0AWWeWCSwmZ T7g+RbfPFlmQp+EwFWOtABXlKC54zgSf+uulGwx5JAUFVUIRBmnHOYi/lUiE0yhpnb1KCA7f u/W+DkwGerXqhhe9TvQoGwgCKNfzFPZoM+gZrm+kWv03QLUCr210n4cwaCPJ0Nr9Z3c582xc bCUVbsjt7BN0CFa2BByulrx5xD9sDAYIqfLCcZetAqsTRGxM7LD0kh5WlKzOeAXj5r8DOrU2 GdZS33uKZI/kZJZVytSmZpswDsKhnGzRN1BANGP8sC+WD4eRXajOmNh2HL4P+meO1TlM3GLl EQd2shHFY0qjEo7wxKZI1RyZZ5AgJnSmehrPCyuIyVY210CbMaIKHUIsTqRgY5GaNME24w7h TyyVCy2qAM8fLJ4Vw5bycM/u5xfWm7gyTb9V1TkZ3o1MTrEsrcqFiRrBY94Rs0oQkZvunqia c+NprYSaOG1Cta14o94eMH271Kka/reEwSZkC7T+o9hZ4zi2CcLcY0DXj0qdId7vUKSJjEep c++s8ncFekh1MPhkOgNj8pk17OAESanmDwksmzh1j12lgA5lTFPrJeRNu6/isC2zyZhTwMWs k3LkcTa8ZXxh0RfWAqgx/ogKPk4ZxOXQEZetkEyTFghbRH2BIwARAQABtCNOaWtvbGF5IEJv cmlzb3YgPG5ib3Jpc292QHN1c2UuY29tPokCOAQTAQIAIgUCWIo48QIbAwYLCQgHAwIGFQgC CQoLBBYCAwECHgECF4AACgkQcb6CRuU/KFc0eg/9GLD3wTQz9iZHMFbjiqTCitD7B6dTLV1C ddZVlC8Hm/TophPts1bWZORAmYIihHHI1EIF19+bfIr46pvfTu0yFrJDLOADMDH+Ufzsfy2v HSqqWV/nOSWGXzh8bgg/ncLwrIdEwBQBN9SDS6aqsglagvwFD91UCg/TshLlRxD5BOnuzfzI Leyx2c6YmH7Oa1R4MX9Jo79SaKwdHt2yRN3SochVtxCyafDlZsE/efp21pMiaK1HoCOZTBp5 VzrIP85GATh18pN7YR9CuPxxN0V6IzT7IlhS4Jgj0NXh6vi1DlmKspr+FOevu4RVXqqcNTSS E2rycB2v6cttH21UUdu/0FtMBKh+rv8+yD49FxMYnTi1jwVzr208vDdRU2v7Ij/TxYt/v4O8 V+jNRKy5Fevca/1xroQBICXsNoFLr10X5IjmhAhqIH8Atpz/89ItS3+HWuE4BHB6RRLM0gy8 T7rN6ja+KegOGikp/VTwBlszhvfLhyoyjXI44Tf3oLSFM+8+qG3B7MNBHOt60CQlMkq0fGXd mm4xENl/SSeHsiomdveeq7cNGpHi6i6ntZK33XJLwvyf00PD7tip/GUj0Dic/ZUsoPSTF/mG EpuQiUZs8X2xjK/AS/l3wa4Kz2tlcOKSKpIpna7V1+CMNkNzaCOlbv7QwprAerKYywPCoOSC 7P25Ag0EWIoHPgEQAMiUqvRBZNvPvki34O/dcTodvLSyOmK/MMBDrzN8Cnk302XfnGlW/YAQ csMWISKKSpStc6tmD+2Y0z9WjyRqFr3EGfH1RXSv9Z1vmfPzU42jsdZn667UxrRcVQXUgoKg QYx055Q2FdUeaZSaivoIBD9WtJq/66UPXRRr4H/+Y5FaUZx+gWNGmBT6a0S/GQnHb9g3nonD jmDKGw+YO4P6aEMxyy3k9PstaoiyBXnzQASzdOi39BgWQuZfIQjN0aW+Dm8kOAfT5i/yk59h VV6v3NLHBjHVw9kHli3jwvsizIX9X2W8tb1SefaVxqvqO1132AO8V9CbE1DcVT8fzICvGi42 FoV/k0QOGwq+LmLf0t04Q0csEl+h69ZcqeBSQcIMm/Ir+NorfCr6HjrB6lW7giBkQl6hhomn l1mtDP6MTdbyYzEiBFcwQD4terc7S/8ELRRybWQHQp7sxQM/Lnuhs77MgY/e6c5AVWnMKd/z MKm4ru7A8+8gdHeydrRQSWDaVbfy3Hup0Ia76J9FaolnjB8YLUOJPdhI2vbvNCQ2ipxw3Y3c KhVIpGYqwdvFIiz0Fej7wnJICIrpJs/+XLQHyqcmERn3s/iWwBpeogrx2Lf8AGezqnv9woq7 OSoWlwXDJiUdaqPEB/HmGfqoRRN20jx+OOvuaBMPAPb+aKJyle8zABEBAAGJAh8EGAECAAkF AliKBz4CGwwACgkQcb6CRuU/KFdacg/+M3V3Ti9JYZEiIyVhqs+yHb6NMI1R0kkAmzsGQ1jU zSQUz9AVMR6T7v2fIETTT/f5Oout0+Hi9cY8uLpk8CWno9V9eR/B7Ifs2pAA8lh2nW43FFwp IDiSuDbH6oTLmiGCB206IvSuaQCp1fed8U6yuqGFcnf0ZpJm/sILG2ECdFK9RYnMIaeqlNQm iZicBY2lmlYFBEaMXHoy+K7nbOuizPWdUKoKHq+tmZ3iA+qL5s6Qlm4trH28/fPpFuOmgP8P K+7LpYLNSl1oQUr+WlqilPAuLcCo5Vdl7M7VFLMq4xxY/dY99aZx0ZJQYFx0w/6UkbDdFLzN upT7NIN68lZRucImffiWyN7CjH23X3Tni8bS9ubo7OON68NbPz1YIaYaHmnVQCjDyDXkQoKC R82Vf9mf5slj0Vlpf+/Wpsv/TH8X32ajva37oEQTkWNMsDxyw3aPSps6MaMafcN7k60y2Wk/ TCiLsRHFfMHFY6/lq/c0ZdOsGjgpIK0G0z6et9YU6MaPuKwNY4kBdjPNBwHreucrQVUdqRRm RcxmGC6ohvpqVGfhT48ZPZKZEWM+tZky0mO7bhZYxMXyVjBn4EoNTsXy1et9Y1dU3HVJ8fod 5UqrNrzIQFbdeM0/JqSLrtlTcXKJ7cYFa9ZM2AP7UIN9n1UWxq+OPY9YMOewVfYtL8M= Message-ID: <9e38c008-6a3e-cf90-4e65-26066710060e@suse.com> Date: Mon, 9 Sep 2019 17:34:08 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <37228196-3617-e253-6ad1-125e72e6628c@gmx.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On 9.09.19 г. 17:24 ч., Qu Wenruo wrote: > > > On 2019/9/9 下午9:25, Nikolay Borisov wrote: >> >> >> On 5.09.19 г. 10:57 ч., Qu Wenruo wrote: >>> Introduce a function, find_file_type(), to find filetype using >>> INODE_REF. >>> >>> This function will: >>> - Search DIR_INDEX first >>> DIR_INDEX is easier since there is only one item in it. >>> >>> - Valid the DIR_INDEX item >>> If the DIR_INDEX is valid, use the filetype and call it a day. >>> >>> - Search DIR_ITEM then >>> >>> - Valide the DIR_ITEM >>> If valid, call it a day. Or return -ENOENT; >>> >>> This would be used as the primary method to determine the imode in later >>> imode repair code. >>> >>> Signed-off-by: Qu Wenruo >>> --- >>> check/mode-common.c | 99 +++++++++++++++++++++++++++++++++++++++++++++ >>> 1 file changed, 99 insertions(+) >>> >>> diff --git a/check/mode-common.c b/check/mode-common.c >>> index 195b6efaa7aa..c0ddc50a1dd0 100644 >>> --- a/check/mode-common.c >>> +++ b/check/mode-common.c >>> @@ -16,6 +16,7 @@ >>> >>> #include >>> #include "ctree.h" >>> +#include "hash.h" >>> #include "common/internal.h" >>> #include "common/messages.h" >>> #include "transaction.h" >>> @@ -836,6 +837,104 @@ int reset_imode(struct btrfs_trans_handle *trans, struct btrfs_root *root, >>> return ret; >>> } >>> >>> +static int find_file_type(struct btrfs_root *root, u64 ino, u64 dirid, >>> + u64 index, const char *name, u32 name_len, >>> + u32 *imode_ret) >>> +{ >>> + struct btrfs_path path; >>> + struct btrfs_key location; >>> + struct btrfs_key key; >>> + struct btrfs_dir_item *di; >>> + char namebuf[BTRFS_NAME_LEN] = {0}; >>> + unsigned long cur; >>> + unsigned long end; >>> + bool found = false; >>> + u8 filetype; >>> + u32 len; >>> + int ret; >>> + >>> + btrfs_init_path(&path); >>> + >>> + /* Search DIR_INDEX first */ >>> + key.objectid = dirid; >>> + key.offset = index; >>> + key.type = BTRFS_DIR_INDEX_KEY; >>> + >>> + ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0); >>> + if (ret > 0) >>> + ret = -ENOENT; >> >> Even if it returns 1 meaning there is no DIR_INDEX item perhaps it still >> makes sense to go to dir_item: label to search for DIR_ITEM, what if the >> corruption has affected just the DIR_INDEX item? > > I didn't get the point. > > The next line is just going to do dir_item search, just as you mentioned. You are right, however, this is somewhat subtle and the fact I missed it just proves the point. The following will be much better (and explicit): if (ret) goto dir_item In fact setting the -ENOENT on ret > 0 is only needed because of the awkward way the return value of btrfs_search_slot is handled. So yeah, I'm even more convinced that a simple if (ret) goto dir_item (or call a function) is the way to go here. >> >>> + if (ret < 0) >>> + goto dir_item; >> nit: Use elseif to make it more explicit it is a single construct. > > Not sure such usage is recommened, but I see a lot of usage like: > ret = btrfs_search_slot(); > if (ret > 0) > ret = -ENOENT; > if (ret < 0) > goto error; > > So I just followed this practice. > I guess this is debatable. You are right that most of the retval handling is as you say but I think the more "purist" (so to say) way should be an if {} else if {}. Because ultimately you are handling one thing - the return value of btrfs_search_slot. David, what is your take on that ?