hfsplus: add support of manipulation by attributes file
[~shefty/rdma-dev.git] / fs / hfsplus / ioctl.c
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 = dentry->d_inode;
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;
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                 inode->i_flags |= S_IMMUTABLE;
114         else
115                 inode->i_flags &= ~S_IMMUTABLE;
116
117         if (flags & FS_APPEND_FL)
118                 inode->i_flags |= S_APPEND;
119         else
120                 inode->i_flags &= ~S_APPEND;
121
122         if (flags & FS_NODUMP_FL)
123                 hip->userflags |= HFSPLUS_FLG_NODUMP;
124         else
125                 hip->userflags &= ~HFSPLUS_FLG_NODUMP;
126
127         inode->i_ctime = CURRENT_TIME_SEC;
128         mark_inode_dirty(inode);
129
130 out_unlock_inode:
131         mutex_unlock(&inode->i_mutex);
132 out_drop_write:
133         mnt_drop_write_file(file);
134 out:
135         return err;
136 }
137
138 long hfsplus_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
139 {
140         void __user *argp = (void __user *)arg;
141
142         switch (cmd) {
143         case HFSPLUS_IOC_EXT2_GETFLAGS:
144                 return hfsplus_ioctl_getflags(file, argp);
145         case HFSPLUS_IOC_EXT2_SETFLAGS:
146                 return hfsplus_ioctl_setflags(file, argp);
147         case HFSPLUS_IOC_BLESS:
148                 return hfsplus_ioctl_bless(file, argp);
149         default:
150                 return -ENOTTY;
151         }
152 }