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 <hch@xxxxxx>
---
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 <linux/major.h>
#include <linux/root_dev.h>
+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 <linux/init.h>
+#include <linux/mount.h>
+#include <linux/namei.h>
+#include <linux/fs.h>
+#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
