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=-10.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 D2A84C04EBF for ; Wed, 5 Dec 2018 09:42:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9659120878 for ; Wed, 5 Dec 2018 09:42:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="1pHx2QSf" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9659120878 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728923AbeLEJmr (ORCPT ); Wed, 5 Dec 2018 04:42:47 -0500 Received: from mail.kernel.org ([198.145.29.99]:47292 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728038AbeLEJmn (ORCPT ); Wed, 5 Dec 2018 04:42:43 -0500 Received: from sasha-vm.mshome.net (unknown [213.57.143.11]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6382420850; Wed, 5 Dec 2018 09:42:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1544002962; bh=QgND/igT+OcDt8qn2UK+4UTQkUaTXWJsSELaDl06MXg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1pHx2QSfm9N+cfFwkANRIUOBy/NkJ89HgPTRg0PpRChmJWJPINuCEtf6TtJXeU27H GqejbLwJE8FJTowdEwZTJlNmuHeTMAd7Wa15WPTHYpqAcnjI67BS9Rw67rDQm68bv7 IIXfXlSAd1SO15DOC8M+dEmeg74YfreQQUNKegX8= From: Sasha Levin To: stable@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Li Zhijian , Philip Li , Dominik Brodowski , Li Zhijian , Al Viro , Andrew Morton , Linus Torvalds , Sasha Levin Subject: [PATCH AUTOSEL 4.19 122/123] initramfs: clean old path before creating a hardlink Date: Wed, 5 Dec 2018 04:35:54 -0500 Message-Id: <20181205093555.5386-122-sashal@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181205093555.5386-1-sashal@kernel.org> References: <20181205093555.5386-1-sashal@kernel.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Li Zhijian [ Upstream commit 7c0950d455d6ab610d2990a13120f935b75abf2c ] sys_link() can fail due to the new path already existing. This case ofen occurs when we use a concated initrd, for example: 1) prepare a basic rootfs, it contains a regular files rc.local lizhijian@:~/yocto-tiny-i386-2016-04-22$ cat etc/rc.local #!/bin/sh echo "Running /etc/rc.local..." yocto-tiny-i386-2016-04-22$ find . | sed 's,^\./,,' | cpio -o -H newc | gzip -n -9 >../rootfs.cgz 2) create a extra initrd which also includes a etc/rc.local lizhijian@:~/lkp-x86_64/etc$ echo "append initrd" >rc.local lizhijian@:~/lkp/lkp-x86_64/etc$ cat rc.local append initrd lizhijian@:~/lkp/lkp-x86_64/etc$ ln rc.local rc.local.hardlink append initrd lizhijian@:~/lkp/lkp-x86_64/etc$ stat rc.local rc.local.hardlink File: 'rc.local' Size: 14 Blocks: 8 IO Block: 4096 regular file Device: 801h/2049d Inode: 11296086 Links: 2 Access: (0664/-rw-rw-r--) Uid: ( 1002/lizhijian) Gid: ( 1002/lizhijian) Access: 2018-11-15 16:08:28.654464815 +0800 Modify: 2018-11-15 16:07:57.514903210 +0800 Change: 2018-11-15 16:08:24.180228872 +0800 Birth: - File: 'rc.local.hardlink' Size: 14 Blocks: 8 IO Block: 4096 regular file Device: 801h/2049d Inode: 11296086 Links: 2 Access: (0664/-rw-rw-r--) Uid: ( 1002/lizhijian) Gid: ( 1002/lizhijian) Access: 2018-11-15 16:08:28.654464815 +0800 Modify: 2018-11-15 16:07:57.514903210 +0800 Change: 2018-11-15 16:08:24.180228872 +0800 Birth: - lizhijian@:~/lkp/lkp-x86_64$ find . | sed 's,^\./,,' | cpio -o -H newc | gzip -n -9 >../rc-local.cgz lizhijian@:~/lkp/lkp-x86_64$ gzip -dc ../rc-local.cgz | cpio -t . etc etc/rc.local.hardlink <<< it will be extracted first at this initrd etc/rc.local 3) concate 2 initrds and boot lizhijian@:~/lkp$ cat rootfs.cgz rc-local.cgz >concate-initrd.cgz lizhijian@:~/lkp$ qemu-system-x86_64 -nographic -enable-kvm -cpu host -smp 1 -m 1024 -kernel ~/lkp/linux/arch/x86/boot/bzImage -append "console=ttyS0 earlyprint=ttyS0 ignore_loglevel" -initrd ./concate-initr.cgz -serial stdio -nodefaults In this case, sys_link(2) will fail and return -EEXIST, so we can only get the rc.local at rootfs.cgz instead of rc-local.cgz [akpm@linux-foundation.org: move code to avoid forward declaration] Link: http://lkml.kernel.org/r/1542352368-13299-1-git-send-email-lizhijian@cn.fujitsu.com Signed-off-by: Li Zhijian Cc: Philip Li Cc: Dominik Brodowski Cc: Li Zhijian Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- init/initramfs.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) diff --git a/init/initramfs.c b/init/initramfs.c index 640557788026..f6f4a1e4cd54 100644 --- a/init/initramfs.c +++ b/init/initramfs.c @@ -291,16 +291,6 @@ static int __init do_reset(void) return 1; } -static int __init maybe_link(void) -{ - if (nlink >= 2) { - char *old = find_link(major, minor, ino, mode, collected); - if (old) - return (ksys_link(old, collected) < 0) ? -1 : 1; - } - return 0; -} - static void __init clean_path(char *path, umode_t fmode) { struct kstat st; @@ -313,6 +303,18 @@ static void __init clean_path(char *path, umode_t fmode) } } +static int __init maybe_link(void) +{ + if (nlink >= 2) { + char *old = find_link(major, minor, ino, mode, collected); + if (old) { + clean_path(collected, 0); + return (ksys_link(old, collected) < 0) ? -1 : 1; + } + } + return 0; +} + static __initdata int wfd; static int __init do_name(void) -- 2.17.1