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Mon, 9 Sep 2019 09:26:00 -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 BCE39AF8E; Mon, 9 Sep 2019 13:25:57 +0000 (UTC) Subject: Re: [PATCH v2 2/6] btrfs-progs: check/common: Introduce a function to find imode using INODE_REF To: Qu Wenruo , linux-btrfs@vger.kernel.org References: <20190905075800.1633-1-wqu@suse.com> <20190905075800.1633-3-wqu@suse.com> 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: <4e7099d2-5b4c-1fa3-ffdf-2b3332ed0b88@suse.com> Date: Mon, 9 Sep 2019 16:25:56 +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: <20190905075800.1633-3-wqu@suse.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 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? > + if (ret < 0) > + goto dir_item; nit: Use elseif to make it more explicit it is a single construct. > + di = btrfs_item_ptr(path.nodes[0], path.slots[0], > + struct btrfs_dir_item); > + btrfs_dir_item_key_to_cpu(path.nodes[0], di, &location); > + > + /* Various basic check */ > + if (location.objectid != ino || location.type != BTRFS_INODE_ITEM_KEY || > + location.offset != 0) > + goto dir_item; > + filetype = btrfs_dir_type(path.nodes[0], di); > + if (filetype >= BTRFS_FT_MAX || filetype == BTRFS_FT_UNKNOWN) > + goto dir_item; > + len = min_t(u32, btrfs_item_size_nr(path.nodes[0], path.slots[0]) - > + sizeof(*di), BTRFS_NAME_LEN); > + len = min_t(u32, len, btrfs_dir_name_len(path.nodes[0], di)); > + read_extent_buffer(path.nodes[0], namebuf, (unsigned long)(di + 1), len); > + if (name_len != len || memcmp(namebuf, name, len)) > + goto dir_item; > + > + /* Got a correct filetype */ > + found = true; > + *imode_ret = btrfs_type_to_imode(filetype); > + ret = 0; > + goto out; > + > +dir_item: This function is needlessly structured in an awkward way. E.g. there is no dependence between "searching by DIR INDEX item" and "searching by DIR_ITEM". I think the best way is to have 3 function: Top level find_file_type which will call find_file_type_by_dir_index if the reeturn value is negative -> call 2nd function find_file_type_by_dir_item. This will result in 3 fairly short and easy to read/parse functions. > + btrfs_release_path(&path); > + key.objectid = dirid; > + key.offset = btrfs_name_hash(name, name_len); > + > + ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0); > + if (ret > 0) > + ret = -ENOENT; > + if (ret < 0) { > + btrfs_release_path(&path); > + return ret; > + } ditto about the else if construct > + cur = btrfs_item_ptr_offset(path.nodes[0], path.slots[0]); > + end = cur + btrfs_item_size_nr(path.nodes[0], path.slots[0]); > + while (cur < end) { Just checking : this is needed in case we have items whose names create a crc32 collision in the DIR_ITEM offset? > + di = (struct btrfs_dir_item *)cur; > + btrfs_dir_item_key_to_cpu(path.nodes[0], di, &location); > + /* Various basic check */ > + if (location.objectid != ino || > + location.type != BTRFS_INODE_ITEM_KEY || > + location.offset != 0) > + goto next;> + filetype = btrfs_dir_type(path.nodes[0], di); > + if (filetype >= BTRFS_FT_MAX || filetype == BTRFS_FT_UNKNOWN) > + goto next; > + len = min_t(u32, BTRFS_NAME_LEN, > + btrfs_item_size_nr(path.nodes[0], path.slots[0]) - > + sizeof(*di)); > + len = min_t(u32, len, btrfs_dir_name_len(path.nodes[0], di)); > + read_extent_buffer(path.nodes[0], namebuf, > + (unsigned long)(di + 1), len); > + if (name_len != len || memcmp(namebuf, name, len)) > + goto next; > + *imode_ret = btrfs_type_to_imode(filetype); > + found = true; > + goto out; > +next: > + cur += btrfs_dir_name_len(path.nodes[0], di) + sizeof(*di); If this line is moved right after assigning to 'di' instead of having a 'next' label you can simply use the 'continue' keyword > + } > +out: > + btrfs_release_path(&path); > + if (!found && !ret) > + ret = -ENOENT; > + return ret; > +} > + > /* > * Reset the inode mode of the inode specified by @path. > * >