drivers/staging/autofs/root.c

   1 /* -*- linux-c -*- --------------------------------------------------------- *
   2  *
   3  * drivers/staging/autofs/root.c
   4  *
   5  *  Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
   6  *
   7  * This file is part of the Linux kernel and is made available under
   8  * the terms of the GNU General Public License, version 2, or at your
   9  * option, any later version, incorporated herein by reference.
  10  *
  11  * ------------------------------------------------------------------------- */
  12
  13 #include <linux/capability.h>
  14 #include <linux/errno.h>
  15 #include <linux/stat.h>
  16 #include <linux/slab.h>
  17 #include <linux/param.h>
  18 #include <linux/time.h>
  19 #include <linux/compat.h>
  20 #include <linux/smp_lock.h>
  21 #include "autofs_i.h"
  22
  23 static int autofs_root_readdir(struct file *,void *,filldir_t);
  24 static struct dentry *autofs_root_lookup(struct inode *,struct dentry *, struct nameidata *);
  25 static int autofs_root_symlink(struct inode *,struct dentry *,const char *);
  26 static int autofs_root_unlink(struct inode *,struct dentry *);
  27 static int autofs_root_rmdir(struct inode *,struct dentry *);
  28 static int autofs_root_mkdir(struct inode *,struct dentry *,int);
  29 static long autofs_root_ioctl(struct file *,unsigned int,unsigned long);
  30 #ifdef CONFIG_COMPAT
  31 static long autofs_root_compat_ioctl(struct file *,unsigned int,unsigned long);
  32 #endif
  33
  34 const struct file_operations autofs_root_operations = {
  35         .llseek         = generic_file_llseek,
  36         .read           = generic_read_dir,
  37         .readdir        = autofs_root_readdir,
  38         .unlocked_ioctl = autofs_root_ioctl,
  39 #ifdef CONFIG_COMPAT
  40         .compat_ioctl   = autofs_root_compat_ioctl,
  41 #endif
  42 };
  43
  44 const struct inode_operations autofs_root_inode_operations = {
  45         .lookup         = autofs_root_lookup,
  46         .unlink         = autofs_root_unlink,
  47         .symlink        = autofs_root_symlink,
  48         .mkdir          = autofs_root_mkdir,
  49         .rmdir          = autofs_root_rmdir,
  50 };
  51
  52 static int autofs_root_readdir(struct file *filp, void *dirent, filldir_t filldir)
  53 {
  54         struct autofs_dir_ent *ent = NULL;
  55         struct autofs_dirhash *dirhash;
  56         struct autofs_sb_info *sbi;
  57         struct inode * inode = filp->f_path.dentry->d_inode;
  58         off_t onr, nr;
  59
  60         lock_kernel();
  61
  62         sbi = autofs_sbi(inode->i_sb);
  63         dirhash = &sbi->dirhash;
  64         nr = filp->f_pos;
  65
  66         switch(nr)
  67         {
  68         case 0:
  69                 if (filldir(dirent, ".", 1, nr, inode->i_ino, DT_DIR) < 0)
  70                         goto out;
  71                 filp->f_pos = ++nr;
  72                 /* fall through */
  73         case 1:
  74                 if (filldir(dirent, "..", 2, nr, inode->i_ino, DT_DIR) < 0)
  75                         goto out;
  76                 filp->f_pos = ++nr;
  77                 /* fall through */
  78         default:
  79                 while (onr = nr, ent = autofs_hash_enum(dirhash,&nr,ent)) {
  80                         if (!ent->dentry || d_mountpoint(ent->dentry)) {
  81                                 if (filldir(dirent,ent->name,ent->len,onr,ent->ino,DT_UNKNOWN) < 0)
  82                                         goto out;
  83                                 filp->f_pos = nr;
  84                         }
  85                 }
  86                 break;
  87         }
  88
  89 out:
  90         unlock_kernel();
  91         return 0;
  92 }
  93
  94 static int try_to_fill_dentry(struct dentry *dentry, struct super_block *sb, struct autofs_sb_info *sbi)
  95 {
  96         struct inode * inode;
  97         struct autofs_dir_ent *ent;
  98         int status = 0;
  99
 100         if (!(ent = autofs_hash_lookup(&sbi->dirhash, &dentry->d_name))) {
 101                 do {
 102                         if (status && dentry->d_inode) {
 103                                 if (status != -ENOENT)
 104                                         printk("autofs warning: lookup failure on positive dentry, status = %d, name = %s\n", status, dentry->d_name.name);
 105                                 return 0; /* Try to get the kernel to invalidate this dentry */
 106                         }
 107
 108                         /* Turn this into a real negative dentry? */
 109                         if (status == -ENOENT) {
 110                                 dentry->d_time = jiffies + AUTOFS_NEGATIVE_TIMEOUT;
 111                                 dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
 112                                 return 1;
 113                         } else if (status) {
 114                                 /* Return a negative dentry, but leave it "pending" */
 115                                 return 1;
 116                         }
 117                         status = autofs_wait(sbi, &dentry->d_name);
 118                 } while (!(ent = autofs_hash_lookup(&sbi->dirhash, &dentry->d_name)));
 119         }
 120
 121         /* Abuse this field as a pointer to the directory entry, used to
 122            find the expire list pointers */
 123         dentry->d_time = (unsigned long) ent;
 124
 125         if (!dentry->d_inode) {
 126                 inode = autofs_iget(sb, ent->ino);
 127                 if (IS_ERR(inode)) {
 128                         /* Failed, but leave pending for next time */
 129                         return 1;
 130                 }
 131                 dentry->d_inode = inode;
 132         }
 133
 134         /* If this is a directory that isn't a mount point, bitch at the
 135            daemon and fix it in user space */
 136         if (S_ISDIR(dentry->d_inode->i_mode) && !d_mountpoint(dentry)) {
 137                 return !autofs_wait(sbi, &dentry->d_name);
 138         }
 139
 140         /* We don't update the usages for the autofs daemon itself, this
 141            is necessary for recursive autofs mounts */
 142         if (!autofs_oz_mode(sbi)) {
 143                 autofs_update_usage(&sbi->dirhash,ent);
 144         }
 145
 146         dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
 147         return 1;
 148 }
 149
 150
 151 /*
 152  * Revalidate is called on every cache lookup.  Some of those
 153  * cache lookups may actually happen while the dentry is not
 154  * yet completely filled in, and revalidate has to delay such
 155  * lookups..
 156  */
 157 static int autofs_revalidate(struct dentry * dentry, struct nameidata *nd)
 158 {
 159         struct inode * dir;
 160         struct autofs_sb_info *sbi;
 161         struct autofs_dir_ent *ent;
 162         int res;
 163
 164         lock_kernel();
 165         dir = dentry->d_parent->d_inode;
 166         sbi = autofs_sbi(dir->i_sb);
 167
 168         /* Pending dentry */
 169         if (dentry->d_flags & DCACHE_AUTOFS_PENDING) {
 170                 if (autofs_oz_mode(sbi))
 171                         res = 1;
 172                 else
 173                         res = try_to_fill_dentry(dentry, dir->i_sb, sbi);
 174                 unlock_kernel();
 175                 return res;
 176         }
 177
 178         /* Negative dentry.. invalidate if "old" */
 179         if (!dentry->d_inode) {
 180                 unlock_kernel();
 181                 return (dentry->d_time - jiffies <= AUTOFS_NEGATIVE_TIMEOUT);
 182         }
 183
 184         /* Check for a non-mountpoint directory */
 185         if (S_ISDIR(dentry->d_inode->i_mode) && !d_mountpoint(dentry)) {
 186                 if (autofs_oz_mode(sbi))
 187                         res = 1;
 188                 else
 189                         res = try_to_fill_dentry(dentry, dir->i_sb, sbi);
 190                 unlock_kernel();
 191                 return res;
 192         }
 193
 194         /* Update the usage list */
 195         if (!autofs_oz_mode(sbi)) {
 196                 ent = (struct autofs_dir_ent *) dentry->d_time;
 197                 if (ent)
 198                         autofs_update_usage(&sbi->dirhash,ent);
 199         }
 200         unlock_kernel();
 201         return 1;
 202 }
 203
 204 static const struct dentry_operations autofs_dentry_operations = {
 205         .d_revalidate   = autofs_revalidate,
 206 };
 207
 208 static struct dentry *autofs_root_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
 209 {
 210         struct autofs_sb_info *sbi;
 211         int oz_mode;
 212
 213         DPRINTK(("autofs_root_lookup: name = "));
 214         lock_kernel();
 215         autofs_say(dentry->d_name.name,dentry->d_name.len);
 216
 217         if (dentry->d_name.len > NAME_MAX) {
 218                 unlock_kernel();
 219                 return ERR_PTR(-ENAMETOOLONG);/* File name too long to exist */
 220         }
 221
 222         sbi = autofs_sbi(dir->i_sb);
 223
 224         oz_mode = autofs_oz_mode(sbi);
 225         DPRINTK(("autofs_lookup: pid = %u, pgrp = %u, catatonic = %d, "
 226                                 "oz_mode = %d\n", task_pid_nr(current),
 227                                 task_pgrp_nr(current), sbi->catatonic,
 228                                 oz_mode));
 229
 230         /*
 231          * Mark the dentry incomplete, but add it. This is needed so
 232          * that the VFS layer knows about the dentry, and we can count
 233          * on catching any lookups through the revalidate.
 234          *
 235          * Let all the hard work be done by the revalidate function that
 236          * needs to be able to do this anyway..
 237          *
 238          * We need to do this before we release the directory semaphore.
 239          */
 240         dentry->d_op = &autofs_dentry_operations;
 241         dentry->d_flags |= DCACHE_AUTOFS_PENDING;
 242         d_add(dentry, NULL);
 243
 244         mutex_unlock(&dir->i_mutex);
 245         autofs_revalidate(dentry, nd);
 246         mutex_lock(&dir->i_mutex);
 247
 248         /*
 249          * If we are still pending, check if we had to handle
 250          * a signal. If so we can force a restart..
 251          */
 252         if (dentry->d_flags & DCACHE_AUTOFS_PENDING) {
 253                 /* See if we were interrupted */
 254                 if (signal_pending(current)) {
 255                         sigset_t *sigset = &current->pending.signal;
 256                         if (sigismember (sigset, SIGKILL) ||
 257                             sigismember (sigset, SIGQUIT) ||
 258                             sigismember (sigset, SIGINT)) {
 259                                 unlock_kernel();
 260                                 return ERR_PTR(-ERESTARTNOINTR);
 261                         }
 262                 }
 263         }
 264         unlock_kernel();
 265
 266         /*
 267          * If this dentry is unhashed, then we shouldn't honour this
 268          * lookup even if the dentry is positive.  Returning ENOENT here
 269          * doesn't do the right thing for all system calls, but it should
 270          * be OK for the operations we permit from an autofs.
 271          */
 272         if (dentry->d_inode && d_unhashed(dentry))
 273                 return ERR_PTR(-ENOENT);
 274
 275         return NULL;
 276 }
 277
 278 static int autofs_root_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
 279 {
 280         struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
 281         struct autofs_dirhash *dh = &sbi->dirhash;
 282         struct autofs_dir_ent *ent;
 283         unsigned int n;
 284         int slsize;
 285         struct autofs_symlink *sl;
 286         struct inode *inode;
 287
 288         DPRINTK(("autofs_root_symlink: %s <- ", symname));
 289         autofs_say(dentry->d_name.name,dentry->d_name.len);
 290
 291         lock_kernel();
 292         if (!autofs_oz_mode(sbi)) {
 293                 unlock_kernel();
 294                 return -EACCES;
 295         }
 296
 297         if (autofs_hash_lookup(dh, &dentry->d_name)) {
 298                 unlock_kernel();
 299                 return -EEXIST;
 300         }
 301
 302         n = find_first_zero_bit(sbi->symlink_bitmap,AUTOFS_MAX_SYMLINKS);
 303         if (n >= AUTOFS_MAX_SYMLINKS) {
 304                 unlock_kernel();
 305                 return -ENOSPC;
 306         }
 307
 308         set_bit(n,sbi->symlink_bitmap);
 309         sl = &sbi->symlink[n];
 310         sl->len = strlen(symname);
 311         sl->data = kmalloc(slsize = sl->len+1, GFP_KERNEL);
 312         if (!sl->data) {
 313                 clear_bit(n,sbi->symlink_bitmap);
 314                 unlock_kernel();
 315                 return -ENOSPC;
 316         }
 317
 318         ent = kmalloc(sizeof(struct autofs_dir_ent), GFP_KERNEL);
 319         if (!ent) {
 320                 kfree(sl->data);
 321                 clear_bit(n,sbi->symlink_bitmap);
 322                 unlock_kernel();
 323                 return -ENOSPC;
 324         }
 325
 326         ent->name = kmalloc(dentry->d_name.len+1, GFP_KERNEL);
 327         if (!ent->name) {
 328                 kfree(sl->data);
 329                 kfree(ent);
 330                 clear_bit(n,sbi->symlink_bitmap);
 331                 unlock_kernel();
 332                 return -ENOSPC;
 333         }
 334
 335         memcpy(sl->data,symname,slsize);
 336         sl->mtime = get_seconds();
 337
 338         ent->ino = AUTOFS_FIRST_SYMLINK + n;
 339         ent->hash = dentry->d_name.hash;
 340         memcpy(ent->name, dentry->d_name.name, 1+(ent->len = dentry->d_name.len));
 341         ent->dentry = NULL;     /* We don't keep the dentry for symlinks */
 342
 343         autofs_hash_insert(dh,ent);
 344
 345         inode = autofs_iget(dir->i_sb, ent->ino);
 346         if (IS_ERR(inode))
 347                 return PTR_ERR(inode);
 348
 349         d_instantiate(dentry, inode);
 350         unlock_kernel();
 351         return 0;
 352 }
 353
 354 /*
 355  * NOTE!
 356  *
 357  * Normal filesystems would do a "d_delete()" to tell the VFS dcache
 358  * that the file no longer exists. However, doing that means that the
 359  * VFS layer can turn the dentry into a negative dentry, which we
 360  * obviously do not want (we're dropping the entry not because it
 361  * doesn't exist, but because it has timed out).
 362  *
 363  * Also see autofs_root_rmdir()..
 364  */
 365 static int autofs_root_unlink(struct inode *dir, struct dentry *dentry)
 366 {
 367         struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
 368         struct autofs_dirhash *dh = &sbi->dirhash;
 369         struct autofs_dir_ent *ent;
 370         unsigned int n;
 371
 372         /* This allows root to remove symlinks */
 373         lock_kernel();
 374         if (!autofs_oz_mode(sbi) && !capable(CAP_SYS_ADMIN)) {
 375                 unlock_kernel();
 376                 return -EACCES;
 377         }
 378
 379         ent = autofs_hash_lookup(dh, &dentry->d_name);
 380         if (!ent) {
 381                 unlock_kernel();
 382                 return -ENOENT;
 383         }
 384
 385         n = ent->ino - AUTOFS_FIRST_SYMLINK;
 386         if (n >= AUTOFS_MAX_SYMLINKS) {
 387                 unlock_kernel();
 388                 return -EISDIR; /* It's a directory, dummy */
 389         }
 390         if (!test_bit(n,sbi->symlink_bitmap)) {
 391                 unlock_kernel();
 392                 return -EINVAL; /* Nonexistent symlink?  Shouldn't happen */
 393         }
 394
 395         dentry->d_time = (unsigned long)(struct autofs_dirhash *)NULL;
 396         autofs_hash_delete(ent);
 397         clear_bit(n,sbi->symlink_bitmap);
 398         kfree(sbi->symlink[n].data);
 399         d_drop(dentry);
 400
 401         unlock_kernel();
 402         return 0;
 403 }
 404
 405 static int autofs_root_rmdir(struct inode *dir, struct dentry *dentry)
 406 {
 407         struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
 408         struct autofs_dirhash *dh = &sbi->dirhash;
 409         struct autofs_dir_ent *ent;
 410
 411         lock_kernel();
 412         if (!autofs_oz_mode(sbi)) {
 413                 unlock_kernel();
 414                 return -EACCES;
 415         }
 416
 417         ent = autofs_hash_lookup(dh, &dentry->d_name);
 418         if (!ent) {
 419                 unlock_kernel();
 420                 return -ENOENT;
 421         }
 422
 423         if ((unsigned int)ent->ino < AUTOFS_FIRST_DIR_INO) {
 424                 unlock_kernel();
 425                 return -ENOTDIR; /* Not a directory */
 426         }
 427
 428         if (ent->dentry != dentry) {
 429                 printk("autofs_rmdir: odentry != dentry for entry %s\n", dentry->d_name.name);
 430         }
 431
 432         dentry->d_time = (unsigned long)(struct autofs_dir_ent *)NULL;
 433         autofs_hash_delete(ent);
 434         drop_nlink(dir);
 435         d_drop(dentry);
 436         unlock_kernel();
 437
 438         return 0;
 439 }
 440
 441 static int autofs_root_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 442 {
 443         struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
 444         struct autofs_dirhash *dh = &sbi->dirhash;
 445         struct autofs_dir_ent *ent;
 446         struct inode *inode;
 447         ino_t ino;
 448
 449         lock_kernel();
 450         if (!autofs_oz_mode(sbi)) {
 451                 unlock_kernel();
 452                 return -EACCES;
 453         }
 454
 455         ent = autofs_hash_lookup(dh, &dentry->d_name);
 456         if (ent) {
 457                 unlock_kernel();
 458                 return -EEXIST;
 459         }
 460
 461         if (sbi->next_dir_ino < AUTOFS_FIRST_DIR_INO) {
 462                 printk("autofs: Out of inode numbers -- what the heck did you do??\n");
 463                 unlock_kernel();
 464                 return -ENOSPC;
 465         }
 466         ino = sbi->next_dir_ino++;
 467
 468         ent = kmalloc(sizeof(struct autofs_dir_ent), GFP_KERNEL);
 469         if (!ent) {
 470                 unlock_kernel();
 471                 return -ENOSPC;
 472         }
 473
 474         ent->name = kmalloc(dentry->d_name.len+1, GFP_KERNEL);
 475         if (!ent->name) {
 476                 kfree(ent);
 477                 unlock_kernel();
 478                 return -ENOSPC;
 479         }
 480
 481         ent->hash = dentry->d_name.hash;
 482         memcpy(ent->name, dentry->d_name.name, 1+(ent->len = dentry->d_name.len));
 483         ent->ino = ino;
 484         ent->dentry = dentry;
 485         autofs_hash_insert(dh,ent);
 486
 487         inc_nlink(dir);
 488
 489         inode = autofs_iget(dir->i_sb, ino);
 490         if (IS_ERR(inode)) {
 491                 drop_nlink(dir);
 492                 return PTR_ERR(inode);
 493         }
 494
 495         d_instantiate(dentry, inode);
 496         unlock_kernel();
 497
 498         return 0;
 499 }
 500
 501 /* Get/set timeout ioctl() operation */
 502 #ifdef CONFIG_COMPAT
 503 static inline int autofs_compat_get_set_timeout(struct autofs_sb_info *sbi,
 504                                          unsigned int __user *p)
 505 {
 506         unsigned long ntimeout;
 507
 508         if (get_user(ntimeout, p) ||
 509             put_user(sbi->exp_timeout / HZ, p))
 510                 return -EFAULT;
 511
 512         if (ntimeout > UINT_MAX/HZ)
 513                 sbi->exp_timeout = 0;
 514         else
 515                 sbi->exp_timeout = ntimeout * HZ;
 516
 517         return 0;
 518 }
 519 #endif
 520
 521 static inline int autofs_get_set_timeout(struct autofs_sb_info *sbi,
 522                                          unsigned long __user *p)
 523 {
 524         unsigned long ntimeout;
 525
 526         if (get_user(ntimeout, p) ||
 527             put_user(sbi->exp_timeout / HZ, p))
 528                 return -EFAULT;
 529
 530         if (ntimeout > ULONG_MAX/HZ)
 531                 sbi->exp_timeout = 0;
 532         else
 533                 sbi->exp_timeout = ntimeout * HZ;
 534
 535         return 0;
 536 }
 537
 538 /* Return protocol version */
 539 static inline int autofs_get_protover(int __user *p)
 540 {
 541         return put_user(AUTOFS_PROTO_VERSION, p);
 542 }
 543
 544 /* Perform an expiry operation */
 545 static inline int autofs_expire_run(struct super_block *sb,
 546                                     struct autofs_sb_info *sbi,
 547                                     struct vfsmount *mnt,
 548                                     struct autofs_packet_expire __user *pkt_p)
 549 {
 550         struct autofs_dir_ent *ent;
 551         struct autofs_packet_expire pkt;
 552
 553         memset(&pkt,0,sizeof pkt);
 554
 555         pkt.hdr.proto_version = AUTOFS_PROTO_VERSION;
 556         pkt.hdr.type = autofs_ptype_expire;
 557
 558         if (!sbi->exp_timeout || !(ent = autofs_expire(sb,sbi,mnt)))
 559                 return -EAGAIN;
 560
 561         pkt.len = ent->len;
 562         memcpy(pkt.name, ent->name, pkt.len);
 563         pkt.name[pkt.len] = '\0';
 564
 565         if (copy_to_user(pkt_p, &pkt, sizeof(struct autofs_packet_expire)))
 566                 return -EFAULT;
 567
 568         return 0;
 569 }
 570
 571 /*
 572  * ioctl()'s on the root directory is the chief method for the daemon to
 573  * generate kernel reactions
 574  */
 575 static int autofs_do_root_ioctl(struct inode *inode, struct file *filp,
 576                              unsigned int cmd, unsigned long arg)
 577 {
 578         struct autofs_sb_info *sbi = autofs_sbi(inode->i_sb);
 579         void __user *argp = (void __user *)arg;
 580
 581         DPRINTK(("autofs_ioctl: cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u\n",cmd,arg,sbi,task_pgrp_nr(current)));
 582
 583         if (_IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) ||
 584              _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT)
 585                 return -ENOTTY;
 586
 587         if (!autofs_oz_mode(sbi) && !capable(CAP_SYS_ADMIN))
 588                 return -EPERM;
 589
 590         switch(cmd) {
 591         case AUTOFS_IOC_READY:  /* Wait queue: go ahead and retry */
 592                 return autofs_wait_release(sbi,(autofs_wqt_t)arg,0);
 593         case AUTOFS_IOC_FAIL:   /* Wait queue: fail with ENOENT */
 594                 return autofs_wait_release(sbi,(autofs_wqt_t)arg,-ENOENT);
 595         case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */
 596                 autofs_catatonic_mode(sbi);
 597                 return 0;
 598         case AUTOFS_IOC_PROTOVER: /* Get protocol version */
 599                 return autofs_get_protover(argp);
 600 #ifdef CONFIG_COMPAT
 601         case AUTOFS_IOC_SETTIMEOUT32:
 602                 return autofs_compat_get_set_timeout(sbi, argp);
 603 #endif
 604         case AUTOFS_IOC_SETTIMEOUT:
 605                 return autofs_get_set_timeout(sbi, argp);
 606         case AUTOFS_IOC_EXPIRE:
 607                 return autofs_expire_run(inode->i_sb, sbi, filp->f_path.mnt,
 608                                          argp);
 609         default:
 610                 return -ENOSYS;
 611         }
 612
 613 }
 614
 615 static long autofs_root_ioctl(struct file *filp,
 616                              unsigned int cmd, unsigned long arg)
 617 {
 618         int ret;
 619
 620         lock_kernel();
 621         ret = autofs_do_root_ioctl(filp->f_path.dentry->d_inode,
 622                                    filp, cmd, arg);
 623         unlock_kernel();
 624
 625         return ret;
 626 }
 627
 628 #ifdef CONFIG_COMPAT
 629 static long autofs_root_compat_ioctl(struct file *filp,
 630                              unsigned int cmd, unsigned long arg)
 631 {
 632         struct inode *inode = filp->f_path.dentry->d_inode;
 633         int ret;
 634
 635         lock_kernel();
 636         if (cmd == AUTOFS_IOC_READY || cmd == AUTOFS_IOC_FAIL)
 637                 ret = autofs_do_root_ioctl(inode, filp, cmd, arg);
 638         else
 639                 ret = autofs_do_root_ioctl(inode, filp, cmd,
 640                         (unsigned long)compat_ptr(arg));
 641         unlock_kernel();
 642
 643         return ret;
 644 }
 645 #endif