init: add an init_umount helper
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 <hch@lst.de>
diff --git a/fs/init.c b/fs/init.c
index c6eb724e..9c8e31f 100644
--- a/fs/init.c
+++ b/fs/init.c
@@ -23,3 +23,17 @@ 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 72ea0b6..491d1e6 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 2c4d759..a730179 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 af9ea88..a5a2e7f 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 e438161..1a4f5d8 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 1f93362..6b020a0 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);
}
}