init: add an init_dup helper

Add a simple helper to grab a reference to a file and install it at
the next available fd, and switch the early init code over to it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/init_syscalls.h b/include/linux/init_syscalls.h
index 3654b525ac0b..92045d18cbfc 100644
--- a/include/linux/init_syscalls.h
+++ b/include/linux/init_syscalls.h
@@ -16,3 +16,4 @@ int __init init_unlink(const char *pathname);
 int __init init_mkdir(const char *pathname, umode_t mode);
 int __init init_rmdir(const char *pathname);
 int __init init_utimes(char *filename, struct timespec64 *ts);
+int __init init_dup(struct file *file);