1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * linux/fs/hfsplus/ioctl.c 4 * 5 * Copyright (C) 2003 6 * Ethan Benson <erbenson@alaska.net> 7 * partially derived from linux/fs/ext2/ioctl.c 8 * Copyright (C) 1993, 1994, 1995 9 * Remy Card (card@masi.ibp.fr) 10 * Laboratoire MASI - Institut Blaise Pascal 11 * Universite Pierre et Marie Curie (Paris VI) 12 * 13 * hfsplus ioctls 14 */ 15 16 #include <linux/capability.h> 17 #include <linux/fs.h> 18 #include <linux/mount.h> 19 #include <linux/sched.h> 20 #include <linux/uaccess.h> 21 #include "hfsplus_fs.h" 22 23 /* 24 * "Blessing" an HFS+ filesystem writes metadata to the superblock informing 25 * the platform firmware which file to boot from 26 */ 27 static int hfsplus_ioctl_bless(struct file *file, int __user *user_flags) 28 { 29 struct dentry *dentry = file->f_path.dentry; 30 struct inode *inode = d_inode(dentry); 31 struct hfsplus_sb_info *sbi = HFSPLUS_SB(inode->i_sb); 32 struct hfsplus_vh *vh = sbi->s_vhdr; 33 struct hfsplus_vh *bvh = sbi->s_backup_vhdr; 34 u32 cnid = (unsigned long)dentry->d_fsdata; 35 36 if (!capable(CAP_SYS_ADMIN)) 37 return -EPERM; 38 39 mutex_lock(&sbi->vh_mutex); 40 41 /* Directory containing the bootable system */ 42 vh->finder_info[0] = bvh->finder_info[0] = 43 cpu_to_be32(parent_ino(dentry)); 44 45 /* 46 * Bootloader. Just using the inode here breaks in the case of 47 * hard links - the firmware wants the ID of the hard link file, 48 * but the inode points at the indirect inode 49 */ 50 vh->finder_info[1] = bvh->finder_info[1] = cpu_to_be32(cnid); 51 52 /* Per spec, the OS X system folder - same as finder_info[0] here */ 53 vh->finder_info[5] = bvh->finder_info[5] = 54 cpu_to_be32(parent_ino(dentry)); 55 56 mutex_unlock(&sbi->vh_mutex); 57 return 0; 58 } 59 60 long hfsplus_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 61 { 62 void __user *argp = (void __user *)arg; 63 64 switch (cmd) { 65 case HFSPLUS_IOC_BLESS: 66 return hfsplus_ioctl_bless(file, argp); 67 default: 68 return -ENOTTY; 69 } 70 } 71