init: add an init_mount helper

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@lst.de>

1 files changed, 4 insertions, 0 deletions

diff --git a/include/linux/init_syscalls.h b/include/linux/init_syscalls.h
new file mode 100644
index 000000000000..af9ea88a60e0
--- /dev/null
+++ b/include/linux/init_syscalls.h
@@ -0,0 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+int __init init_mount(const char *dev_name, const char *dir_name,
+		const char *type_page, unsigned long flags, void *data_page);