xref: /openbmc/linux/fs/hfsplus/ioctl.c (revision 65ee8aeb)
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  */
26 static 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 
59 static 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 
75 static 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 
128 out_unlock_inode:
129 	mutex_unlock(&inode->i_mutex);
130 out_drop_write:
131 	mnt_drop_write_file(file);
132 out:
133 	return err;
134 }
135 
136 long 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