LXR linux/fs/coda/pioctl.c

   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 */
  27static int coda_ioctl_permission(struct inode *inode, int mask);
  28static long coda_pioctl(struct file *filp, unsigned int cmd,
  29                        unsigned long user_data);
  30
  31/* exported from this file */
  32const struct inode_operations coda_ioctl_inode_operations = {
  33        .permission     = coda_ioctl_permission,
  34        .setattr        = coda_setattr,
  35};
  36
  37const struct file_operations coda_ioctl_operations = {
  38        .unlocked_ioctl = coda_pioctl,
  39        .llseek         = noop_llseek,
  40};
  41
  42/* the coda pioctl inode ops */
  43static int coda_ioctl_permission(struct inode *inode, int mask)
  44{
  45        return (mask & MAY_EXEC) ? -EACCES : 0;
  46}
  47
  48static 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        if (data.follow)
  67                error = user_path(data.path, &path);
  68        else
  69                error = user_lpath(data.path, &path);
  70
  71        if (error)
  72                return error;
  73
  74        target_inode = d_inode(path.dentry);
  75
  76        /* return if it is not a Coda inode */
  77        if (target_inode->i_sb != inode->i_sb) {
  78                error = -EINVAL;
  79                goto out;
  80        }
  81
  82        /* now proceed to make the upcall */
  83        cnp = ITOC(target_inode);
  84
  85        error = venus_pioctl(inode->i_sb, &(cnp->c_fid), cmd, &data);
  86out:
  87        path_put(&path);
  88        return error;
  89}
  90