Merge git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched
[linux-2.6] / fs / ioctl.c
1 /*
2  *  linux/fs/ioctl.c
3  *
4  *  Copyright (C) 1991, 1992  Linus Torvalds
5  */
6
7 #include <linux/syscalls.h>
8 #include <linux/mm.h>
9 #include <linux/smp_lock.h>
10 #include <linux/capability.h>
11 #include <linux/file.h>
12 #include <linux/fs.h>
13 #include <linux/security.h>
14 #include <linux/module.h>
15
16 #include <asm/uaccess.h>
17 #include <asm/ioctls.h>
18
19 static long do_ioctl(struct file *filp, unsigned int cmd,
20                 unsigned long arg)
21 {
22         int error = -ENOTTY;
23
24         if (!filp->f_op)
25                 goto out;
26
27         if (filp->f_op->unlocked_ioctl) {
28                 error = filp->f_op->unlocked_ioctl(filp, cmd, arg);
29                 if (error == -ENOIOCTLCMD)
30                         error = -EINVAL;
31                 goto out;
32         } else if (filp->f_op->ioctl) {
33                 lock_kernel();
34                 error = filp->f_op->ioctl(filp->f_path.dentry->d_inode,
35                                           filp, cmd, arg);
36                 unlock_kernel();
37         }
38
39  out:
40         return error;
41 }
42
43 static int file_ioctl(struct file *filp, unsigned int cmd,
44                 unsigned long arg)
45 {
46         int error;
47         int block;
48         struct inode * inode = filp->f_path.dentry->d_inode;
49         int __user *p = (int __user *)arg;
50
51         switch (cmd) {
52                 case FIBMAP:
53                 {
54                         struct address_space *mapping = filp->f_mapping;
55                         int res;
56                         /* do we support this mess? */
57                         if (!mapping->a_ops->bmap)
58                                 return -EINVAL;
59                         if (!capable(CAP_SYS_RAWIO))
60                                 return -EPERM;
61                         if ((error = get_user(block, p)) != 0)
62                                 return error;
63
64                         lock_kernel();
65                         res = mapping->a_ops->bmap(mapping, block);
66                         unlock_kernel();
67                         return put_user(res, p);
68                 }
69                 case FIGETBSZ:
70                         return put_user(inode->i_sb->s_blocksize, p);
71                 case FIONREAD:
72                         return put_user(i_size_read(inode) - filp->f_pos, p);
73         }
74
75         return do_ioctl(filp, cmd, arg);
76 }
77
78 /*
79  * When you add any new common ioctls to the switches above and below
80  * please update compat_sys_ioctl() too.
81  *
82  * vfs_ioctl() is not for drivers and not intended to be EXPORT_SYMBOL()'d.
83  * It's just a simple helper for sys_ioctl and compat_sys_ioctl.
84  */
85 int vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd, unsigned long arg)
86 {
87         unsigned int flag;
88         int on, error = 0;
89
90         switch (cmd) {
91                 case FIOCLEX:
92                         set_close_on_exec(fd, 1);
93                         break;
94
95                 case FIONCLEX:
96                         set_close_on_exec(fd, 0);
97                         break;
98
99                 case FIONBIO:
100                         if ((error = get_user(on, (int __user *)arg)) != 0)
101                                 break;
102                         flag = O_NONBLOCK;
103 #ifdef __sparc__
104                         /* SunOS compatibility item. */
105                         if(O_NONBLOCK != O_NDELAY)
106                                 flag |= O_NDELAY;
107 #endif
108                         if (on)
109                                 filp->f_flags |= flag;
110                         else
111                                 filp->f_flags &= ~flag;
112                         break;
113
114                 case FIOASYNC:
115                         if ((error = get_user(on, (int __user *)arg)) != 0)
116                                 break;
117                         flag = on ? FASYNC : 0;
118
119                         /* Did FASYNC state change ? */
120                         if ((flag ^ filp->f_flags) & FASYNC) {
121                                 if (filp->f_op && filp->f_op->fasync) {
122                                         lock_kernel();
123                                         error = filp->f_op->fasync(fd, filp, on);
124                                         unlock_kernel();
125                                 }
126                                 else error = -ENOTTY;
127                         }
128                         if (error != 0)
129                                 break;
130
131                         if (on)
132                                 filp->f_flags |= FASYNC;
133                         else
134                                 filp->f_flags &= ~FASYNC;
135                         break;
136
137                 case FIOQSIZE:
138                         if (S_ISDIR(filp->f_path.dentry->d_inode->i_mode) ||
139                             S_ISREG(filp->f_path.dentry->d_inode->i_mode) ||
140                             S_ISLNK(filp->f_path.dentry->d_inode->i_mode)) {
141                                 loff_t res = inode_get_bytes(filp->f_path.dentry->d_inode);
142                                 error = copy_to_user((loff_t __user *)arg, &res, sizeof(res)) ? -EFAULT : 0;
143                         }
144                         else
145                                 error = -ENOTTY;
146                         break;
147                 default:
148                         if (S_ISREG(filp->f_path.dentry->d_inode->i_mode))
149                                 error = file_ioctl(filp, cmd, arg);
150                         else
151                                 error = do_ioctl(filp, cmd, arg);
152                         break;
153         }
154         return error;
155 }
156
157 asmlinkage long sys_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg)
158 {
159         struct file * filp;
160         int error = -EBADF;
161         int fput_needed;
162
163         filp = fget_light(fd, &fput_needed);
164         if (!filp)
165                 goto out;
166
167         error = security_file_ioctl(filp, cmd, arg);
168         if (error)
169                 goto out_fput;
170
171         error = vfs_ioctl(filp, fd, cmd, arg);
172  out_fput:
173         fput_light(filp, fput_needed);
174  out:
175         return error;
176 }