From patchwork Fri May 17 16:55:19 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 10948283 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D7583912 for ; Fri, 17 May 2019 17:00:03 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C1C5728397 for ; Fri, 17 May 2019 17:00:03 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B2618283A8; Fri, 17 May 2019 17:00:03 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4808D28397 for ; Fri, 17 May 2019 17:00:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727967AbfEQQ76 (ORCPT ); Fri, 17 May 2019 12:59:58 -0400 Received: from lhrrgout.huawei.com ([185.176.76.210]:32953 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726575AbfEQQ76 (ORCPT ); Fri, 17 May 2019 12:59:58 -0400 Received: from lhreml707-cah.china.huawei.com (unknown [172.18.7.106]) by Forcepoint Email with ESMTP id A5B5E1A365CDA136CABA; Fri, 17 May 2019 17:59:56 +0100 (IST) Received: from roberto-HP-EliteDesk-800-G2-DM-65W.huawei.com (10.204.65.154) by smtpsuk.huawei.com (10.201.108.48) with Microsoft SMTP Server (TLS) id 14.3.408.0; Fri, 17 May 2019 17:59:46 +0100 From: Roberto Sassu To: CC: , , , , , , , , , , , , , , , , Roberto Sassu Subject: [PATCH v3 2/2] initramfs: introduce do_readxattrs() Date: Fri, 17 May 2019 18:55:19 +0200 Message-ID: <20190517165519.11507-3-roberto.sassu@huawei.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190517165519.11507-1-roberto.sassu@huawei.com> References: <20190517165519.11507-1-roberto.sassu@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.204.65.154] X-CFilter-Loop: Reflected Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This patch adds support for an alternative method to add xattrs to files in the rootfs filesystem. Instead of extracting them directly from the ram disk image, they are extracted from a regular file called .xattr-list, that can be added by any ram disk generator available today. The file format is: \0 \0 .xattr-list can be generated by executing: $ getfattr --absolute-names -d -h -R -e hex -m - \ | xattr.awk -b > ${initdir}/.xattr-list where the content of the xattr.awk script is: #! /usr/bin/awk -f { if (!length($0)) { printf("%.10x%s\0", len, file); for (x in xattr) { printf("%.8x%s\0", xattr_len[x], x); for (i = 0; i < length(xattr[x]) / 2; i++) { printf("%c", strtonum("0x"substr(xattr[x], i * 2 + 1, 2))); } } i = 0; delete xattr; delete xattr_len; next; }; if (i == 0) { file=$3; len=length(file) + 8 + 1; } if (i > 0) { split($0, a, "="); xattr[a[1]]=substr(a[2], 3); xattr_len[a[1]]=length(a[1]) + 1 + 8 + length(xattr[a[1]]) / 2; len+=xattr_len[a[1]]; }; i++; } Signed-off-by: Roberto Sassu --- init/initramfs.c | 99 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 99 insertions(+) diff --git a/init/initramfs.c b/init/initramfs.c index 0c6dd1d5d3f6..6ec018c6279a 100644 --- a/init/initramfs.c +++ b/init/initramfs.c @@ -13,6 +13,8 @@ #include #include +#define XATTR_LIST_FILENAME ".xattr-list" + static ssize_t __init xwrite(int fd, const char *p, size_t count) { ssize_t out = 0; @@ -382,6 +384,97 @@ static int __init __maybe_unused do_setxattrs(char *pathname) return 0; } +struct path_hdr { + char p_size[10]; /* total size including p_size field */ + char p_data[]; /* \0 */ +}; + +static int __init do_readxattrs(void) +{ + struct path_hdr hdr; + char *path = NULL; + char str[sizeof(hdr.p_size) + 1]; + unsigned long file_entry_size; + size_t size, path_size, total_size; + struct kstat st; + struct file *file; + loff_t pos; + int ret; + + ret = vfs_lstat(XATTR_LIST_FILENAME, &st); + if (ret < 0) + return ret; + + total_size = st.size; + + file = filp_open(XATTR_LIST_FILENAME, O_RDONLY, 0); + if (IS_ERR(file)) + return PTR_ERR(file); + + pos = file->f_pos; + + while (total_size) { + size = kernel_read(file, (char *)&hdr, sizeof(hdr), &pos); + if (size != sizeof(hdr)) { + ret = -EIO; + goto out; + } + + total_size -= size; + + str[sizeof(hdr.p_size)] = 0; + memcpy(str, hdr.p_size, sizeof(hdr.p_size)); + ret = kstrtoul(str, 16, &file_entry_size); + if (ret < 0) + goto out; + + file_entry_size -= sizeof(sizeof(hdr.p_size)); + if (file_entry_size > total_size) { + ret = -EINVAL; + goto out; + } + + path = vmalloc(file_entry_size); + if (!path) { + ret = -ENOMEM; + goto out; + } + + size = kernel_read(file, path, file_entry_size, &pos); + if (size != file_entry_size) { + ret = -EIO; + goto out_free; + } + + total_size -= size; + + path_size = strnlen(path, file_entry_size); + if (path_size == file_entry_size) { + ret = -EINVAL; + goto out_free; + } + + xattr_buf = path + path_size + 1; + xattr_len = file_entry_size - path_size - 1; + + ret = do_setxattrs(path); + vfree(path); + path = NULL; + + if (ret < 0) + break; + } +out_free: + vfree(path); +out: + fput(file); + + if (ret < 0) + error("Unable to parse xattrs"); + + return ret; +} + static __initdata int wfd; static int __init do_name(void) @@ -391,6 +484,11 @@ static int __init do_name(void) if (strcmp(collected, "TRAILER!!!") == 0) { free_hash(); return 0; + } else if (strcmp(collected, XATTR_LIST_FILENAME) == 0) { + struct kstat st; + + if (!vfs_lstat(collected, &st)) + do_readxattrs(); } clean_path(collected, mode); if (S_ISREG(mode)) { @@ -562,6 +660,7 @@ static char * __init unpack_to_rootfs(char *buf, unsigned long len) buf += my_inptr; len -= my_inptr; } + do_readxattrs(); dir_utime(); kfree(name_buf); kfree(symlink_buf);