xref: /openbmc/linux/fs/coda/pioctl.c (revision f9834f18)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Pioctl operations for Coda.
4  * Original version: (C) 1996 Peter Braam
5  * Rewritten for Linux 2.1: (C) 1997 Carnegie Mellon University
6  *
7  * Carnegie Mellon encourages users of this code to contribute improvements
8  * to the Coda project. Contact Peter Braam <coda@cs.cmu.edu>.
9  */
10 
11 #include <linux/types.h>
12 #include <linux/kernel.h>
13 #include <linux/time.h>
14 #include <linux/fs.h>
15 #include <linux/stat.h>
16 #include <linux/errno.h>
17 #include <linux/string.h>
18 #include <linux/namei.h>
19 #include <linux/module.h>
20 #include <linux/uaccess.h>
21 
22 #include <linux/coda.h>
23 #include "coda_psdev.h"
24 #include "coda_linux.h"
25 
26 /* pioctl ops */
27 static int coda_ioctl_permission(struct inode *inode, int mask);
28 static long coda_pioctl(struct file *filp, unsigned int cmd,
29 			unsigned long user_data);
30 
31 /* exported from this file */
32 const struct inode_operations coda_ioctl_inode_operations = {
33 	.permission	= coda_ioctl_permission,
34 	.setattr	= coda_setattr,
35 };
36 
37 const struct file_operations coda_ioctl_operations = {
38 	.unlocked_ioctl	= coda_pioctl,
39 	.llseek		= noop_llseek,
40 };
41 
42 /* the coda pioctl inode ops */
43 static int coda_ioctl_permission(struct inode *inode, int mask)
44 {
45 	return (mask & MAY_EXEC) ? -EACCES : 0;
46 }
47 
48 static long coda_pioctl(struct file *filp, unsigned int cmd,
49 			unsigned long user_data)
50 {
51 	struct path path;
52 	int error;
53 	struct PioctlData data;
54 	struct inode *inode = file_inode(filp);
55 	struct inode *target_inode = NULL;
56 	struct coda_inode_info *cnp;
57 
58 	/* get the Pioctl data arguments from user space */
59 	if (copy_from_user(&data, (void __user *)user_data, sizeof(data)))
60 		return -EINVAL;
61 
62 	/*
63 	 * Look up the pathname. Note that the pathname is in
64 	 * user memory, and namei takes care of this
65 	 */
66 	error = user_path_at(AT_FDCWD, data.path,
67 			     data.follow ? LOOKUP_FOLLOW : 0, &path);
68 	if (error)
69 		return error;
70 
71 	target_inode = d_inode(path.dentry);
72 
73 	/* return if it is not a Coda inode */
74 	if (target_inode->i_sb != inode->i_sb) {
75 		error = -EINVAL;
76 		goto out;
77 	}
78 
79 	/* now proceed to make the upcall */
80 	cnp = ITOC(target_inode);
81 
82 	error = venus_pioctl(inode->i_sb, &(cnp->c_fid), cmd, &data);
83 out:
84 	path_put(&path);
85 	return error;
86 }
87