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(d_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(d_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
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