fs/autofs/root.c

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