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/sched.h>
  13 #include <linux/fs.h>
  14 #include <linux/stat.h>
  15 #include <linux/errno.h>
  16 #include <linux/locks.h>
  17 #include <asm/segment.h>
  18 #include <linux/string.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_cache.h>
  25 #include <linux/coda_psdev.h>
  26
  27 /* pioctl ops */
  28 static int coda_ioctl_permission(struct inode *inode, int mask);
  29 static int coda_ioctl_open(struct inode *i, struct file *f);
  30 static int coda_ioctl_release(struct inode *i, struct file *f);
  31 static int coda_pioctl(struct inode * inode, struct file * filp,
  32                        unsigned int cmd, unsigned long arg);
  33
  34 /* exported from this file */
  35 struct inode_operations coda_ioctl_inode_operations =
  36 {
  37         permission:     coda_ioctl_permission,
  38         setattr:        coda_notify_change,
  39 };
  40
  41 struct file_operations coda_ioctl_operations = {
  42         ioctl:          coda_pioctl,
  43         open:           coda_ioctl_open,
  44         release:        coda_ioctl_release,
  45 };
  46
  47 /* the coda pioctl inode ops */
  48 static int coda_ioctl_permission(struct inode *inode, int mask)
  49 {
  50         ENTRY;
  51
  52         return 0;
  53 }
  54
  55 /* The pioctl file ops*/
  56 int coda_ioctl_open(struct inode *i, struct file *f)
  57 {
  58         ENTRY;
  59
  60         CDEBUG(D_PIOCTL, "File inode number: %ld\n",
  61                f->f_dentry->d_inode->i_ino);
  62
  63         EXIT;
  64         return 0;
  65 }
  66
  67 int coda_ioctl_release(struct inode *i, struct file *f)
  68 {
  69         return 0;
  70 }
  71
  72
  73 static int coda_pioctl(struct inode * inode, struct file * filp,
  74                        unsigned int cmd, unsigned long user_data)
  75 {
  76         struct nameidata nd;
  77         int error;
  78         struct PioctlData data;
  79         struct inode *target_inode = NULL;
  80         struct coda_inode_info *cnp;
  81
  82         ENTRY;
  83         /* get the Pioctl data arguments from user space */
  84         if (copy_from_user(&data, (int *)user_data, sizeof(data))) {
  85             return -EINVAL;
  86         }
  87
  88         /*
  89          * Look up the pathname. Note that the pathname is in
  90          * user memory, and namei takes care of this
  91          */
  92         CDEBUG(D_PIOCTL, "namei, data.follow = %d\n",
  93                data.follow);
  94         if ( data.follow ) {
  95                 error = user_path_walk(data.path, &nd);
  96         } else {
  97                 error = user_path_walk_link(data.path, &nd);
  98         }
  99
 100         if ( error ) {
 101                 CDEBUG(D_PIOCTL, "error: lookup fails.\n");
 102                 return error;
 103         } else {
 104                 target_inode = nd.dentry->d_inode;
 105         }
 106
 107         CDEBUG(D_PIOCTL, "target ino: 0x%ld, dev: 0x%d\n",
 108                target_inode->i_ino, target_inode->i_dev);
 109
 110         /* return if it is not a Coda inode */
 111         if ( target_inode->i_sb != inode->i_sb ) {
 112                 path_release(&nd);
 113                 return  -EINVAL;
 114         }
 115
 116         /* now proceed to make the upcall */
 117         cnp = ITOC(target_inode);
 118
 119         error = venus_pioctl(inode->i_sb, &(cnp->c_fid), cmd, &data);
 120
 121         CDEBUG(D_PIOCTL, "ioctl on inode %ld\n", target_inode->i_ino);
 122         CDEBUG(D_DOWNCALL, "dput on ino: %ld, icount %d, dcount %d\n", target_inode->i_ino,
 123                target_inode->i_count, nd.dentry->d_count);
 124         path_release(&nd);
 125         return error;
 126 }
 127