1/*
2 *  linux/fs/hfsplus/ioctl.c
3 *
4 * Copyright (C) 2003
5 * Ethan Benson <erbenson@alaska.net>
6 * partially derived from linux/fs/ext2/ioctl.c
7 * Copyright (C) 1993, 1994, 1995
8 * Remy Card (card@masi.ibp.fr)
9 * Laboratoire MASI - Institut Blaise Pascal
10 * Universite Pierre et Marie Curie (Paris VI)
11 *
12 * hfsplus ioctls
13 */
14
15#include <linux/capability.h>
16#include <linux/fs.h>
17#include <linux/mount.h>
18#include <linux/sched.h>
19#include <asm/uaccess.h>
20#include "hfsplus_fs.h"
21
22/*
23 * "Blessing" an HFS+ filesystem writes metadata to the superblock informing
24 * the platform firmware which file to boot from
25 */
26static int hfsplus_ioctl_bless(struct file *file, int __user *user_flags)
27{
28	struct dentry *dentry = file->f_path.dentry;
29	struct inode *inode = d_inode(dentry);
30	struct hfsplus_sb_info *sbi = HFSPLUS_SB(inode->i_sb);
31	struct hfsplus_vh *vh = sbi->s_vhdr;
32	struct hfsplus_vh *bvh = sbi->s_backup_vhdr;
33	u32 cnid = (unsigned long)dentry->d_fsdata;
34
35	if (!capable(CAP_SYS_ADMIN))
36		return -EPERM;
37
38	mutex_lock(&sbi->vh_mutex);
39
40	/* Directory containing the bootable system */
41	vh->finder_info[0] = bvh->finder_info[0] =
42		cpu_to_be32(parent_ino(dentry));
43
44	/*
45	 * Bootloader. Just using the inode here breaks in the case of
46	 * hard links - the firmware wants the ID of the hard link file,
47	 * but the inode points at the indirect inode
48	 */
49	vh->finder_info[1] = bvh->finder_info[1] = cpu_to_be32(cnid);
50
51	/* Per spec, the OS X system folder - same as finder_info[0] here */
52	vh->finder_info[5] = bvh->finder_info[5] =
53		cpu_to_be32(parent_ino(dentry));
54
55	mutex_unlock(&sbi->vh_mutex);
56	return 0;
57}
58
59static int hfsplus_ioctl_getflags(struct file *file, int __user *user_flags)
60{
61	struct inode *inode = file_inode(file);
62	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
63	unsigned int flags = 0;
64
65	if (inode->i_flags & S_IMMUTABLE)
66		flags |= FS_IMMUTABLE_FL;
67	if (inode->i_flags & S_APPEND)
68		flags |= FS_APPEND_FL;
69	if (hip->userflags & HFSPLUS_FLG_NODUMP)
70		flags |= FS_NODUMP_FL;
71
72	return put_user(flags, user_flags);
73}
74
75static int hfsplus_ioctl_setflags(struct file *file, int __user *user_flags)
76{
77	struct inode *inode = file_inode(file);
78	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
79	unsigned int flags, new_fl = 0;
80	int err = 0;
81
82	err = mnt_want_write_file(file);
83	if (err)
84		goto out;
85
86	if (!inode_owner_or_capable(inode)) {
87		err = -EACCES;
88		goto out_drop_write;
89	}
90
91	if (get_user(flags, user_flags)) {
92		err = -EFAULT;
93		goto out_drop_write;
94	}
95
96	mutex_lock(&inode->i_mutex);
97
98	if ((flags & (FS_IMMUTABLE_FL|FS_APPEND_FL)) ||
99	    inode->i_flags & (S_IMMUTABLE|S_APPEND)) {
100		if (!capable(CAP_LINUX_IMMUTABLE)) {
101			err = -EPERM;
102			goto out_unlock_inode;
103		}
104	}
105
106	/* don't silently ignore unsupported ext2 flags */
107	if (flags & ~(FS_IMMUTABLE_FL|FS_APPEND_FL|FS_NODUMP_FL)) {
108		err = -EOPNOTSUPP;
109		goto out_unlock_inode;
110	}
111
112	if (flags & FS_IMMUTABLE_FL)
113		new_fl |= S_IMMUTABLE;
114
115	if (flags & FS_APPEND_FL)
116		new_fl |= S_APPEND;
117
118	inode_set_flags(inode, new_fl, S_IMMUTABLE | S_APPEND);
119
120	if (flags & FS_NODUMP_FL)
121		hip->userflags |= HFSPLUS_FLG_NODUMP;
122	else
123		hip->userflags &= ~HFSPLUS_FLG_NODUMP;
124
125	inode->i_ctime = CURRENT_TIME_SEC;
126	mark_inode_dirty(inode);
127
128out_unlock_inode:
129	mutex_unlock(&inode->i_mutex);
130out_drop_write:
131	mnt_drop_write_file(file);
132out:
133	return err;
134}
135
136long hfsplus_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
137{
138	void __user *argp = (void __user *)arg;
139
140	switch (cmd) {
141	case HFSPLUS_IOC_EXT2_GETFLAGS:
142		return hfsplus_ioctl_getflags(file, argp);
143	case HFSPLUS_IOC_EXT2_SETFLAGS:
144		return hfsplus_ioctl_setflags(file, argp);
145	case HFSPLUS_IOC_BLESS:
146		return hfsplus_ioctl_bless(file, argp);
147	default:
148		return -ENOTTY;
149	}
150}
151