init: add an init_chmod helper

Add a simple helper to chmod with a kernel space file name and switch
the early init code over to it.

Signed-off-by: Christoph Hellwig <[email protected]>

Author: Christoph Hellwig

fs/init.c

@@ -96,6 +96,19 @@ int __init init_chown(const char *filename, uid_t user, gid_t group, int flags)
 	return error;
 }
 
+int __init init_chmod(const char *filename, umode_t mode)
+{
+	struct path path;
+	int error;
+
+	error = kern_path(filename, LOOKUP_FOLLOW, &path);
+	if (error)
+		return error;
+	error = chmod_common(&path, mode);
+	path_put(&path);
+	return error;
+}
+
 int __init init_unlink(const char *pathname)
 {
 	return do_unlinkat(AT_FDCWD, getname_kernel(pathname));

fs/internal.h

@@ -131,7 +131,7 @@ extern struct open_how build_open_how(int flags, umode_t mode);
 extern int build_open_flags(const struct open_how *how, struct open_flags *op);
 
 long do_sys_ftruncate(unsigned int fd, loff_t length, int small);
-int do_fchmodat(int dfd, const char __user *filename, umode_t mode);
+int chmod_common(const struct path *path, umode_t mode);
 int do_fchownat(int dfd, const char __user *filename, uid_t user, gid_t group,
 		int flag);
 int chown_common(const struct path *path, uid_t user, gid_t group);

fs/open.c

@@ -563,7 +563,7 @@ SYSCALL_DEFINE1(chroot, const char __user *, filename)
 	return error;
 }
 
-static int chmod_common(const struct path *path, umode_t mode)
+int chmod_common(const struct path *path, umode_t mode)
 {
 	struct inode *inode = path->dentry->d_inode;
 	struct inode *delegated_inode = NULL;
@@ -610,7 +610,7 @@ SYSCALL_DEFINE2(fchmod, unsigned int, fd, umode_t, mode)
 	return err;
 }
 
-int do_fchmodat(int dfd, const char __user *filename, umode_t mode)
+static int do_fchmodat(int dfd, const char __user *filename, umode_t mode)
 {
 	struct path path;
 	int error;

include/linux/init_syscalls.h

@@ -6,5 +6,6 @@ int __init init_umount(const char *name, int flags);
 int __init init_chdir(const char *filename);
 int __init init_chroot(const char *filename);
 int __init init_chown(const char *filename, uid_t user, gid_t group, int flags);
+int __init init_chmod(const char *filename, umode_t mode);
 int __init init_unlink(const char *pathname);
 int __init init_rmdir(const char *pathname);

include/linux/syscalls.h

@@ -1304,13 +1304,6 @@ static inline long ksys_link(const char __user *oldname,
 	return do_linkat(AT_FDCWD, oldname, AT_FDCWD, newname, 0);
 }
 
-extern int do_fchmodat(int dfd, const char __user *filename, umode_t mode);
-
-static inline int ksys_chmod(const char __user *filename, umode_t mode)
-{
-	return do_fchmodat(AT_FDCWD, filename, mode);
-}
-
 long do_faccessat(int dfd, const char __user *filename, int mode, int flags);
 
 static inline long ksys_access(const char __user *filename, int mode)

init/initramfs.c

@@ -350,14 +350,14 @@ static int __init do_name(void)
 	} else if (S_ISDIR(mode)) {
 		ksys_mkdir(collected, mode);
 		init_chown(collected, uid, gid, 0);
-		ksys_chmod(collected, mode);
+		init_chmod(collected, mode);
 		dir_add(collected, mtime);
 	} else if (S_ISBLK(mode) || S_ISCHR(mode) ||
 		   S_ISFIFO(mode) || S_ISSOCK(mode)) {
 		if (maybe_link() == 0) {
 			ksys_mknod(collected, mode, rdev);
 			init_chown(collected, uid, gid, 0);
-			ksys_chmod(collected, mode);
+			init_chmod(collected, mode);
 			do_utime(collected, mtime);
 		}
 	}