LXR linux/fs/coda/pioctl.c

   1/*
   2 * Pioctl operations for Coda.
   3 * Original version: (C) 1996 Peter Braam
   4 * Rewritten for Linux 2.1: (C) 1997 Carnegie Mellon University
   5 *
   6 * Carnegie Mellon encourages users of this code to contribute improvements
   7 * to the Coda project. Contact Peter Braam <coda@cs.cmu.edu>.
   8 */
   9
  10#include <linux/types.h>
  11#include <linux/kernel.h>
  12#include <linux/time.h>
  13#include <linux/fs.h>
  14#include <linux/stat.h>
  15#include <linux/errno.h>
  16#include <linux/string.h>
  17#include <linux/namei.h>
  18#include <linux/module.h>
  19#include <linux/uaccess.h>
  20
  21#include <linux/coda.h>
  22#include <linux/coda_psdev.h>
  23
  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        .owner          = THIS_MODULE,
  39        .unlocked_ioctl = coda_pioctl,
  40        .llseek         = noop_llseek,
  41};
  42
  43/* the coda pioctl inode ops */
  44static int coda_ioctl_permission(struct inode *inode, int mask)
  45{
  46        return (mask & MAY_EXEC) ? -EACCES : 0;
  47}
  48
  49static long coda_pioctl(struct file *filp, unsigned int cmd,
  50                        unsigned long user_data)
  51{
  52        struct path path;
  53        int error;
  54        struct PioctlData data;
  55        struct inode *inode = file_inode(filp);
  56        struct inode *target_inode = NULL;
  57        struct coda_inode_info *cnp;
  58
  59        /* get the Pioctl data arguments from user space */
  60        if (copy_from_user(&data, (void __user *)user_data, sizeof(data)))
  61                return -EINVAL;
  62
  63        /*
  64         * Look up the pathname. Note that the pathname is in
  65         * user memory, and namei takes care of this
  66         */
  67        if (data.follow)
  68                error = user_path(data.path, &path);
  69        else
  70                error = user_lpath(data.path, &path);
  71
  72        if (error)
  73                return error;
  74
  75        target_inode = d_inode(path.dentry);
  76
  77        /* return if it is not a Coda inode */
  78        if (target_inode->i_sb != inode->i_sb) {
  79                error = -EINVAL;
  80                goto out;
  81        }
  82
  83        /* now proceed to make the upcall */
  84        cnp = ITOC(target_inode);
  85
  86        error = venus_pioctl(inode->i_sb, &(cnp->c_fid), cmd, &data);
  87out:
  88        path_put(&path);
  89        return error;
  90}
  91