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 <asm/uaccess.h>
  20
  21 #include <linux/coda.h>
  22 #include <linux/coda_linux.h>
  23 #include <linux/coda_fs_i.h>
  24 #include <linux/coda_psdev.h>
  25
  26 #include <linux/smp_lock.h>
  27
  28 /* pioctl ops */
  29 static int coda_ioctl_permission(struct inode *inode, int mask);
  30 static long coda_pioctl(struct file *filp, unsigned int cmd,
  31                         unsigned long user_data);
  32
  33 /* exported from this file */
  34 const struct inode_operations coda_ioctl_inode_operations = {
  35         .permission     = coda_ioctl_permission,
  36         .setattr        = coda_setattr,
  37 };
  38
  39 const struct file_operations coda_ioctl_operations = {
  40         .owner          = THIS_MODULE,
  41         .unlocked_ioctl = coda_pioctl,
  42         .llseek         = noop_llseek,
  43 };
  44
  45 /* the coda pioctl inode ops */
  46 static int coda_ioctl_permission(struct inode *inode, int mask)
  47 {
  48         return (mask & MAY_EXEC) ? -EACCES : 0;
  49 }
  50
  51 static long coda_pioctl(struct file *filp, unsigned int cmd,
  52                         unsigned long user_data)
  53 {
  54         struct path path;
  55         int error;
  56         struct PioctlData data;
  57         struct inode *inode = filp->f_dentry->d_inode;
  58         struct inode *target_inode = NULL;
  59         struct coda_inode_info *cnp;
  60
  61         lock_kernel();
  62
  63         /* get the Pioctl data arguments from user space */
  64         if (copy_from_user(&data, (void __user *)user_data, sizeof(data))) {
  65                 error = -EINVAL;
  66                 goto out;
  67         }
  68
  69         /*
  70          * Look up the pathname. Note that the pathname is in
  71          * user memory, and namei takes care of this
  72          */
  73         if (data.follow)
  74                 error = user_path(data.path, &path);
  75         else
  76                 error = user_lpath(data.path, &path);
  77
  78         if (error)
  79                 goto out;
  80         else
  81                 target_inode = path.dentry->d_inode;
  82
  83         /* return if it is not a Coda inode */
  84         if (target_inode->i_sb != inode->i_sb) {
  85                 path_put(&path);
  86                 error = -EINVAL;
  87                 goto out;
  88         }
  89
  90         /* now proceed to make the upcall */
  91         cnp = ITOC(target_inode);
  92
  93         error = venus_pioctl(inode->i_sb, &(cnp->c_fid), cmd, &data);
  94
  95         path_put(&path);
  96
  97 out:
  98         unlock_kernel();
  99         return error;
 100 }