From patchwork Fri May 11 09:18:51 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrzej Lossowsk X-Patchwork-Id: 911853 X-Patchwork-Delegate: blogic@openwrt.org Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=lists.infradead.org (client-ip=2607:7c80:54:e::133; helo=bombadil.infradead.org; envelope-from=lede-dev-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=wp.pl Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="g3c/0gz1"; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=wp.pl header.i=@wp.pl header.b="KnQqLLop"; dkim-atps=neutral Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 40j3BL4YZxz9s02 for ; Fri, 11 May 2018 18:27:54 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Subject:MIME-Version:Message-ID:To:From :Date:Reply-To:Cc:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=Xq36Vt7fBe0Xv3ugxHua1+zuqG5yE/eHJjGcijRjaP0=; b=g3c/0gz1uflxms TVzac8BFNk+FL7QKQWph3Zoya+YiRgLgrnnERYMuT5Y2jcCnXITFivmdOls0ii+GwIAZxT3o0csvO MLArmC2qUbVGuy88xoeWB2qgnl155GSqEHUTbTbPVwfXLXKYJ2FXeq8lg1rl29bPgQFvz0CerhAoi TsN7+JeVRv9Ug9fDIdmKJHFxz1rRTsgsWSPWriaotFlLZkgWhs0hp5wMtNTrMhkkakcwDHOXC3q2x tr4RmnH7m8X8BSmbODd/+cbKsljj+phb7UDlXsQ57oDc2bfdshLSx5JY+lrgZ3a6FdSaMdifkuEDv DQYfz5OgSphshCjjY4cQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1fH3Oz-0002LQ-G1; Fri, 11 May 2018 08:27:45 +0000 Received: from mx3.wp.pl ([212.77.101.9]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1fH3Hu-00047A-Iu for lede-dev@lists.infradead.org; Fri, 11 May 2018 08:20:32 +0000 Received: (wp-smtpd smtp.wp.pl 10145 invoked from network); 11 May 2018 10:20:06 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=wp.pl; s=1024a; t=1526026806; bh=0dwVcB7dfyUwDV8dodtkg0joY81pD8+d+LKOzz/2Ifo=; h=From:Sender:To:Subject; b=KnQqLLopuGoJEW7AfZhyM/oXt5x06htVsMCR8EXC0YOulImnigHYZlYiONp7JAqw1 bbzySyingqbP3o+4/7KJJ5tgAXuWAMehna01RB0XWHEINBUl9VDE6EUy4Xmj76t+X0 kAc0b5XOX59p0ta4oEpL9ZbZifOqjCyYqNW6kHcc= Received: from c205-90.icpnet.pl (HELO akosowski.local) (alossek@wp.pl@[85.221.205.90]) (envelope-sender ) by smtp.wp.pl (WP-SMTPD) with ECDHE-RSA-AES256-SHA encrypted SMTP for ; 11 May 2018 10:20:06 +0200 Date: Fri, 11 May 2018 10:18:51 +0100 From: Andrzej Lossowsk To: lede-dev@lists.infradead.org Message-ID: X-Mailer: TortoiseGit MIME-Version: 1.0 X-WP-MailID: 322e6d30511d024bb7f729270349888e X-WP-AV: skaner antywirusowy Poczty Wirtualnej Polski X-WP-SPAM: NO 000000A [sRPE] X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20180511_012027_128155_40E9235D X-CRM114-Status: GOOD ( 10.21 ) X-Spam-Score: -0.1 (/) X-Spam-Report: SpamAssassin version 3.4.1 on bombadil.infradead.org summary: Content analysis details: (-0.1 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [212.77.101.9 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (alossek[at]wp.pl) -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain Subject: [LEDE-DEV] [PATCH] fstools: add middle layer (original root overlay) to overlayfs when pivot the /overlay to the USB disk. X-BeenThere: lede-dev@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Lede-dev" Errors-To: lede-dev-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org Currently after pivot to the USB disk (extroot), configuration and data from original root overlay are gone. Still accessible, but all previous configuration steps must be repeated (or data from original root overlay must be copied to new USB disk overlay). The idea is to "merge" original root overlay with overlay from the USB disk. Using overlayfs multiple lower layers it can be done. All data from original root overlay will be accessible (as readonly layer) after pivot to the USB disk. Original root overlay (for exmaple /dev/mtdblock3) will be mounted to /overlay/internal (as readonly) Upper directory from original root overlay (/dev/mtdblock3/upper) will be the top (readonly layer), then "/" will be the bottom layer (readonly layer), an extroot still will be upper (writable layer). Signed-off-by: Andrzej Lossowski --- libfstools/extroot.c | 65 ++++++++++++++++++++++++++++++++++++++++++++++++- libfstools/libfstools.h | 3 +++ libfstools/mount.c | 27 +++++++++++++++++--- 3 files changed, 90 insertions(+), 5 deletions(-) diff --git a/libfstools/extroot.c b/libfstools/extroot.c index 418df94..bbb0a3a 100644 --- a/libfstools/extroot.c +++ b/libfstools/extroot.c @@ -22,6 +22,7 @@ #include #include "libfstools.h" +#include "volume.h" char const *extroot_prefix = NULL; @@ -104,7 +105,7 @@ int mount_extroot(void) if (mount_move("/tmp/extroot", "", "/overlay")) { ULOG_ERR("moving extroot failed - continue normal boot\n"); umount("/tmp/extroot/overlay"); - } else if (fopivot("/overlay", "/rom")) { + } else if (fopivot_multi("/overlay", "/rom")) { ULOG_ERR("switching to extroot failed - continue normal boot\n"); umount("/overlay"); } else { @@ -119,3 +120,65 @@ int mount_extroot(void) } return -1; } + +int fopivot_multi(char *rw_root, char *ro_root) +{ + if (mount_internal_overlay()) { + ULOG_ERR("mounting /tmp/overlay failed\n"); + } else if (mkdir("/overlay/internal", 0755)) { + ULOG_ERR("failed to mkdir /overlay/internal: %m\n"); + } else if (mount_move("/tmp/overlay", "/overlay/internal", "")) { + umount("/tmp/overlay"); + } else if (mfopivot(rw_root, ro_root, "/overlay/internal/upper")) { + umount("/overlay/internal"); + } else { + return 0; + } + return -1; +} + +int mount_internal_overlay() +{ + struct volume *v = volume_find("rootfs_data"); + + if (!v) + return -1; + + volume_init(v); + char *mp; + mp = find_mount_point(v->blk, 0); + if (mp) { + ULOG_ERR("rootfs_data:%s is already mounted as %s\n", v->blk, mp); + return -1; + } + + char *fstype; + switch (volume_identify(v)) { + case FS_EXT4: + fstype = "ext4"; + break; + case FS_F2FS: + fstype = "f2fs"; + break; + case FS_UBIFS: + fstype = "ubifs"; + break; + case FS_JFFS2: + default: + fstype = "jffs2"; + break; + } + + if (mkdir("/tmp/overlay", 0755)) { + ULOG_ERR("failed to mkdir /tmp/overlay: %m\n"); + return -1; + } + + if (mount(v->blk, "/tmp/overlay", fstype, MS_NOATIME | MS_RDONLY, NULL)) { + ULOG_ERR("failed to mount -t %s %s /tmp/overlay: %m\n", fstype, v->blk); + return -1; + } + + return 0; +} + diff --git a/libfstools/libfstools.h b/libfstools/libfstools.h index f27307a..8c740a4 100644 --- a/libfstools/libfstools.h +++ b/libfstools/libfstools.h @@ -46,6 +46,9 @@ extern int mount_overlay(struct volume *v); extern int mount_move(const char *oldroot, const char *newroot, const char *dir); extern int pivot(char *new, char *old); extern int fopivot(char *rw_root, char *ro_root); +extern int mfopivot(char *rw_root, char *ro_lowerlevel0, char *ro_lowerlevel1); +extern int fopivot_multi(char *rw_root, char *ro_root); +extern int mount_internal_overlay(); extern int ramoverlay(void); extern int find_overlay_mount(char *overlay); diff --git a/libfstools/mount.c b/libfstools/mount.c index c7f2789..bb82390 100644 --- a/libfstools/mount.c +++ b/libfstools/mount.c @@ -94,7 +94,20 @@ pivot(char *new, char *old) int fopivot(char *rw_root, char *ro_root) { - char overlay[64], mount_options[64]; + return mfopivot(rw_root, ro_root, NULL); +} + +/** + * fopivot - switch to overlay using passed dir as upper one + * + * @rw_root: writable directory that will be used as upper dir + * @ro_root: directory where old root will be put + * @ro_lowerlevel1: directory where internal overlay will be put + */ +int +mfopivot(char *rw_root, char *ro_root, char *ro_lowerlevel1) +{ + char overlay[64], mount_options[128]; if (find_filesystem("overlay")) { ULOG_ERR("BUG: no suitable fs found\n"); @@ -110,15 +123,21 @@ fopivot(char *rw_root, char *ro_root) */ snprintf(mount_options, sizeof(mount_options), "lowerdir=/,upperdir=%s", rw_root); if (mount(overlay, "/mnt", "overlayfs", MS_NOATIME, mount_options)) { - char upperdir[64], workdir[64], upgrade[64], upgrade_dest[64]; + char upperdir[64], workdir[64], upgrade[64], upgrade_dest[64], lowerdir[64]; struct stat st; snprintf(upperdir, sizeof(upperdir), "%s/upper", rw_root); snprintf(workdir, sizeof(workdir), "%s/work", rw_root); snprintf(upgrade, sizeof(upgrade), "%s/sysupgrade.tgz", rw_root); snprintf(upgrade_dest, sizeof(upgrade_dest), "%s/sysupgrade.tgz", upperdir); - snprintf(mount_options, sizeof(mount_options), "lowerdir=/,upperdir=%s,workdir=%s", - upperdir, workdir); + + if (ro_lowerlevel1) + snprintf(lowerdir, sizeof(lowerdir), "%s:/", ro_lowerlevel1); + else + snprintf(lowerdir, sizeof(lowerdir), "/"); + + snprintf(mount_options, sizeof(mount_options), "lowerdir=%s,upperdir=%s,workdir=%s", + lowerdir, upperdir, workdir); /* * Overlay FS v23 and later requires both a upper and