From patchwork Sun Jul 26 07:13:43 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 11685553 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id AD16213A4 for ; Sun, 26 Jul 2020 07:15:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 952DB2073E for ; Sun, 26 Jul 2020 07:15:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="bfOxXSY6" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726891AbgGZHPa (ORCPT ); Sun, 26 Jul 2020 03:15:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59874 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727044AbgGZHOU (ORCPT ); Sun, 26 Jul 2020 03:14:20 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2E826C0619D2; Sun, 26 Jul 2020 00:14:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=96uXhtyamFtvQkAESxk194kUh7qM+YnbONVR+/K73lk=; b=bfOxXSY6tl/sGMrFtg+EXNdxoq W6lwkmVsQK9n1md/MZMmNm1roESKE32JL1dD/ljLRWTG2RVWNI/IMPmkZXerresenPTCVHHRPT0l3 6Qqba5iV8vuWFDhSIWHRJ4NYjl/AnHyjzB5ppQHhJrurGNezJ0QInKVvB2K7cfIv1tnZJXv87aJ7f UiO/oadEB2+brXaVRcjfJq62qDweiJzMlmTnE7HMjHbdFwjFIcqGAtzIlHLS73I6pPZ4pEAvroaOR dWvlaLftovSHwxorWTGIYszyUyJNwJNmTrxjLG5VwVl21x6NHX3a/o7PYh2GbJfEdDYHyQy77eOcb A/8E/tAw==; Received: from [2001:4bb8:18c:2acc:5ff1:d0b0:8643:670e] (helo=localhost) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jzarO-0002RJ-V3; Sun, 26 Jul 2020 07:14:16 +0000 From: Christoph Hellwig To: Al Viro , Linus Torvalds Cc: Greg Kroah-Hartman , "Rafael J. Wysocki" , linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org Subject: [PATCH 08/21] init: add an init_umount helper Date: Sun, 26 Jul 2020 09:13:43 +0200 Message-Id: <20200726071356.287160-9-hch@lst.de> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200726071356.287160-1-hch@lst.de> References: <20200726071356.287160-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Like ksys_umount, but takes a kernel pointer for the destination path. Switch over the umount in the init code, which just happen to work due to the implicit set_fs(KERNEL_DS) during early init right now. Signed-off-by: Christoph Hellwig --- fs/for_init.c | 14 ++++++++++++++ fs/internal.h | 1 + fs/namespace.c | 4 ++-- include/linux/init_syscalls.h | 1 + include/linux/syscalls.h | 1 - init/do_mounts_initrd.c | 2 +- 6 files changed, 19 insertions(+), 4 deletions(-) diff --git a/fs/for_init.c b/fs/for_init.c index 6a04cc8d8557c4..7a039b6d107c92 100644 --- a/fs/for_init.c +++ b/fs/for_init.c @@ -19,3 +19,17 @@ int __init init_mount(const char *dev_name, const char *dir_name, path_put(&path); return ret; } + +int __init init_umount(const char *name, int flags) +{ + int lookup_flags = LOOKUP_MOUNTPOINT; + struct path path; + int ret; + + if (!(flags & UMOUNT_NOFOLLOW)) + lookup_flags |= LOOKUP_FOLLOW; + ret = kern_path(name, lookup_flags, &path); + if (ret) + return ret; + return path_umount(&path, flags); +} diff --git a/fs/internal.h b/fs/internal.h index 72ea0b6f7435a4..491d1e63809b37 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -92,6 +92,7 @@ extern void dissolve_on_fput(struct vfsmount *); int path_mount(const char *dev_name, struct path *path, const char *type_page, unsigned long flags, void *data_page); +int path_umount(struct path *path, int flags); /* * fs_struct.c diff --git a/fs/namespace.c b/fs/namespace.c index 2c4d7592097485..a7301790abb211 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1706,7 +1706,7 @@ static inline bool may_mandlock(void) } #endif -static int path_umount(struct path *path, int flags) +int path_umount(struct path *path, int flags) { struct mount *mnt; int retval; @@ -1736,7 +1736,7 @@ static int path_umount(struct path *path, int flags) return retval; } -int ksys_umount(char __user *name, int flags) +static int ksys_umount(char __user *name, int flags) { int lookup_flags = LOOKUP_MOUNTPOINT; struct path path; diff --git a/include/linux/init_syscalls.h b/include/linux/init_syscalls.h index af9ea88a60e0bd..a5a2e7f1991691 100644 --- a/include/linux/init_syscalls.h +++ b/include/linux/init_syscalls.h @@ -2,3 +2,4 @@ int __init init_mount(const char *dev_name, const char *dir_name, const char *type_page, unsigned long flags, void *data_page); +int __init init_umount(const char *name, int flags); diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index e43816198e6001..1a4f5d8ee7044b 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -1236,7 +1236,6 @@ asmlinkage long sys_ni_syscall(void); * the ksys_xyzyyz() functions prototyped below. */ -int ksys_umount(char __user *name, int flags); int ksys_chroot(const char __user *filename); ssize_t ksys_write(unsigned int fd, const char __user *buf, size_t count); int ksys_chdir(const char __user *filename); diff --git a/init/do_mounts_initrd.c b/init/do_mounts_initrd.c index 1f9336209ad9cc..6b020a06990251 100644 --- a/init/do_mounts_initrd.c +++ b/init/do_mounts_initrd.c @@ -122,7 +122,7 @@ static void __init handle_initrd(void) else printk("failed\n"); printk(KERN_NOTICE "Unmounting old root\n"); - ksys_umount("/old", MNT_DETACH); + init_umount("/old", MNT_DETACH); } }