From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: [PATCH 12/24] init: add an init_mount helper Date: Tue, 21 Jul 2020 18:28:06 +0200 Message-ID: <20200721162818.197315-13-hch@lst.de> References: <20200721162818.197315-1-hch@lst.de> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20200721162818.197315-1-hch-jcswGhMUV9g@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Al Viro , Linus Torvalds Cc: Greg Kroah-Hartman , "Rafael J. Wysocki" , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-raid-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-raid.ids Like do_mount, but takes a kernel pointer for the destination path. Switch over the mounts in the init code and devtmpfs to it, which just happen to work due to the implicit set_fs(KERNEL_DS) during early init right now. Signed-off-by: Christoph Hellwig --- init/Makefile | 2 +- init/do_mounts.c | 8 ++++---- init/do_mounts.h | 3 +++ init/do_mounts_initrd.c | 6 +++--- init/fs.c | 20 ++++++++++++++++++++ 5 files changed, 31 insertions(+), 8 deletions(-) create mode 100644 init/fs.c diff --git a/init/Makefile b/init/Makefile index 6bc37f64b3617c..7d4b57d3cf7eac 100644 --- a/init/Makefile +++ b/init/Makefile @@ -5,7 +5,7 @@ ccflags-y := -fno-function-sections -fno-data-sections -obj-y := main.o version.o mounts.o +obj-y := main.o version.o fs.o mounts.o ifneq ($(CONFIG_BLK_DEV_INITRD),y) obj-y += noinitramfs.o else diff --git a/init/do_mounts.c b/init/do_mounts.c index 4f4ceb35805503..4812e21d149cab 100644 --- a/init/do_mounts.c +++ b/init/do_mounts.c @@ -395,16 +395,16 @@ static int __init do_mount_root(const char *name, const char *fs, int ret; if (data) { - /* do_mount() requires a full page as fifth argument */ + /* init_mount() requires a full page as fifth argument */ p = alloc_page(GFP_KERNEL); if (!p) return -ENOMEM; data_page = page_address(p); - /* zero-pad. do_mount() will make sure it's terminated */ + /* zero-pad. init_mount() will make sure it's terminated */ strncpy(data_page, data, PAGE_SIZE); } - ret = do_mount(name, "/root", fs, flags, data_page); + ret = init_mount(name, "/root", fs, flags, data_page); if (ret) goto out; @@ -628,7 +628,7 @@ void __init prepare_namespace(void) mount_root(); out: devtmpfs_mount(); - do_mount(".", "/", NULL, MS_MOVE, NULL); + init_mount(".", "/", NULL, MS_MOVE, NULL); ksys_chroot("."); } diff --git a/init/do_mounts.h b/init/do_mounts.h index 15d256658a3093..ce4f95fff6bc16 100644 --- a/init/do_mounts.h +++ b/init/do_mounts.h @@ -9,6 +9,9 @@ #include #include +int __init init_mount(const char *dev_name, const char *dir_name, + const char *type_page, unsigned long flags, void *data_page); + void mount_block_root(char *name, int flags); void mount_root(void); void prepare_namespace(void); diff --git a/init/do_mounts_initrd.c b/init/do_mounts_initrd.c index 3fabbc82513506..63a3eebd36e76b 100644 --- a/init/do_mounts_initrd.c +++ b/init/do_mounts_initrd.c @@ -63,7 +63,7 @@ static int __init init_linuxrc(struct subprocess_info *info, struct cred *new) console_on_rootfs(); /* move initrd over / and chdir/chroot in initrd root */ ksys_chdir("/root"); - do_mount(".", "/", NULL, MS_MOVE, NULL); + init_mount(".", "/", NULL, MS_MOVE, NULL); ksys_chroot("."); ksys_setsid(); return 0; @@ -100,7 +100,7 @@ static void __init handle_initrd(void) current->flags &= ~PF_FREEZER_SKIP; /* move initrd to rootfs' /old */ - do_mount("..", ".", NULL, MS_MOVE, NULL); + init_mount("..", ".", NULL, MS_MOVE, NULL); /* switch root and cwd back to / of rootfs */ ksys_chroot(".."); @@ -114,7 +114,7 @@ static void __init handle_initrd(void) mount_root(); printk(KERN_NOTICE "Trying to move old root to /initrd ... "); - error = do_mount("/old", "/root/initrd", NULL, MS_MOVE, NULL); + error = init_mount("/old", "/root/initrd", NULL, MS_MOVE, NULL); if (!error) printk("okay\n"); else { diff --git a/init/fs.c b/init/fs.c new file mode 100644 index 00000000000000..73423f5461f934 --- /dev/null +++ b/init/fs.c @@ -0,0 +1,20 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include "do_mounts.h" + +int __init init_mount(const char *dev_name, const char *dir_name, + const char *type_page, unsigned long flags, void *data_page) +{ + struct path path; + int ret; + + ret = kern_path(dir_name, LOOKUP_FOLLOW, &path); + if (ret) + return ret; + ret = path_mount(dev_name, &path, type_page, flags, data_page); + path_put(&path); + return ret; +} -- 2.27.0