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 /* pioctl ops */
  27 static int coda_ioctl_permission(struct inode *inode, int mask,
  28                                  struct nameidata *nd);
  29 static int coda_pioctl(struct inode * inode, struct file * filp,
  30                        unsigned int cmd, unsigned long user_data);
  31
  32 /* exported from this file */
  33 const struct inode_operations coda_ioctl_inode_operations =
  34 {
  35         .permission     = coda_ioctl_permission,
  36         .setattr        = coda_setattr,
  37 };
  38
  39 const struct file_operations coda_ioctl_operations = {
  40         .owner          = THIS_MODULE,
  41         .ioctl          = coda_pioctl,
  42 };
  43
  44 /* the coda pioctl inode ops */
  45 static int coda_ioctl_permission(struct inode *inode, int mask,
  46                                  struct nameidata *nd)
  47 {
  48         return 0;
  49 }
  50
  51 static int coda_pioctl(struct inode * inode, struct file * filp,
  52                        unsigned int cmd, unsigned long user_data)
  53 {
  54         struct nameidata nd;
  55         int error;
  56         struct PioctlData data;
  57         struct inode *target_inode = NULL;
  58         struct coda_inode_info *cnp;
  59
  60         /* get the Pioctl data arguments from user space */
  61         if (copy_from_user(&data, (void __user *)user_data, sizeof(data))) {
  62             return -EINVAL;
  63         }
  64
  65         /*
  66          * Look up the pathname. Note that the pathname is in
  67          * user memory, and namei takes care of this
  68          */
  69         if ( data.follow ) {
  70                 error = user_path_walk(data.path, &nd);
  71         } else {
  72                 error = user_path_walk_link(data.path, &nd);
  73         }
  74
  75         if ( error ) {
  76                 return error;
  77         } else {
  78                 target_inode = nd.dentry->d_inode;
  79         }
  80
  81         /* return if it is not a Coda inode */
  82         if ( target_inode->i_sb != inode->i_sb ) {
  83                 path_release(&nd);
  84                 return  -EINVAL;
  85         }
  86
  87         /* now proceed to make the upcall */
  88         cnp = ITOC(target_inode);
  89
  90         error = venus_pioctl(inode->i_sb, &(cnp->c_fid), cmd, &data);
  91
  92         path_release(&nd);
  93         return error;
  94 }
  95