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 };
  43
  44 /* the coda pioctl inode ops */
  45 static int coda_ioctl_permission(struct inode *inode, int mask)
  46 {
  47         return (mask & MAY_EXEC) ? -EACCES : 0;
  48 }
  49
  50 static long coda_pioctl(struct file *filp, unsigned int cmd,
  51                         unsigned long user_data)
  52 {
  53         struct path path;
  54         int error;
  55         struct PioctlData data;
  56         struct inode *inode = filp->f_dentry->d_inode;
  57         struct inode *target_inode = NULL;
  58         struct coda_inode_info *cnp;
  59
  60         lock_kernel();
  61
  62         /* get the Pioctl data arguments from user space */
  63         if (copy_from_user(&data, (void __user *)user_data, sizeof(data))) {
  64                 error = -EINVAL;
  65                 goto out;
  66         }
  67
  68         /*
  69          * Look up the pathname. Note that the pathname is in
  70          * user memory, and namei takes care of this
  71          */
  72         if (data.follow)
  73                 error = user_path(data.path, &path);
  74         else
  75                 error = user_lpath(data.path, &path);
  76
  77         if (error)
  78                 goto out;
  79         else
  80                 target_inode = path.dentry->d_inode;
  81
  82         /* return if it is not a Coda inode */
  83         if (target_inode->i_sb != inode->i_sb) {
  84                 path_put(&path);
  85                 error = -EINVAL;
  86                 goto out;
  87         }
  88
  89         /* now proceed to make the upcall */
  90         cnp = ITOC(target_inode);
  91
  92         error = venus_pioctl(inode->i_sb, &(cnp->c_fid), cmd, &data);
  93
  94         path_put(&path);
  95
  96 out:
  97         unlock_kernel();
  98         return error;
  99 }