fs/open.c

   1 /*
   2  *  linux/fs/open.c
   3  *
   4  *  Copyright (C) 1991, 1992  Linus Torvalds
   5  */
   6
   7 #include <linux/string.h>
   8 #include <linux/mm.h>
   9 #include <linux/utime.h>
  10 #include <linux/file.h>
  11 #include <linux/smp_lock.h>
  12 #include <linux/quotaops.h>
  13
  14 #include <asm/uaccess.h>
  15
  16 int vfs_statfs(struct super_block *sb, struct statfs *buf)
  17 {
  18         int retval = -ENODEV;
  19
  20         if (sb) {
  21                 retval = -ENOSYS;
  22                 if (sb->s_op && sb->s_op->statfs) {
  23                         memset(buf, 0, sizeof(struct statfs));
  24                         lock_kernel();
  25                         retval = sb->s_op->statfs(sb, buf);
  26                         unlock_kernel();
  27                 }
  28         }
  29         return retval;
  30 }
  31
  32
  33 asmlinkage long sys_statfs(const char * path, struct statfs * buf)
  34 {
  35         struct nameidata nd;
  36         int error;
  37
  38         error = user_path_walk(path, &nd);
  39         if (!error) {
  40                 struct statfs tmp;
  41                 error = vfs_statfs(nd.dentry->d_inode->i_sb, &tmp);
  42                 if (!error && copy_to_user(buf, &tmp, sizeof(struct statfs)))
  43                         error = -EFAULT;
  44                 path_release(&nd);
  45         }
  46         return error;
  47 }
  48
  49 asmlinkage long sys_fstatfs(unsigned int fd, struct statfs * buf)
  50 {
  51         struct file * file;
  52         struct statfs tmp;
  53         int error;
  54
  55         error = -EBADF;
  56         file = fget(fd);
  57         if (!file)
  58                 goto out;
  59         error = vfs_statfs(file->f_dentry->d_inode->i_sb, &tmp);
  60         if (!error && copy_to_user(buf, &tmp, sizeof(struct statfs)))
  61                 error = -EFAULT;
  62         fput(file);
  63 out:
  64         return error;
  65 }
  66
  67 int do_truncate(struct dentry *dentry, loff_t length)
  68 {
  69         struct inode *inode = dentry->d_inode;
  70         int error;
  71         struct iattr newattrs;
  72
  73         /* Not pretty: "inode->i_size" shouldn't really be signed. But it is. */
  74         if (length < 0)
  75                 return -EINVAL;
  76
  77         down(&inode->i_sem);
  78         newattrs.ia_size = length;
  79         newattrs.ia_valid = ATTR_SIZE | ATTR_CTIME;
  80         error = notify_change(dentry, &newattrs);
  81         up(&inode->i_sem);
  82         return error;
  83 }
  84
  85 static inline long do_sys_truncate(const char * path, loff_t length)
  86 {
  87         struct nameidata nd;
  88         struct inode * inode;
  89         int error;
  90
  91         error = -EINVAL;
  92         if (length < 0) /* sorry, but loff_t says... */
  93                 goto out;
  94
  95         error = user_path_walk(path, &nd);
  96         if (error)
  97                 goto out;
  98         inode = nd.dentry->d_inode;
  99
 100         error = -EACCES;
 101         if (S_ISDIR(inode->i_mode))
 102                 goto dput_and_out;
 103
 104         error = permission(inode,MAY_WRITE);
 105         if (error)
 106                 goto dput_and_out;
 107
 108         error = -EROFS;
 109         if (IS_RDONLY(inode))
 110                 goto dput_and_out;
 111
 112         error = -EPERM;
 113         if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
 114                 goto dput_and_out;
 115
 116         lock_kernel();
 117         error = get_write_access(inode);
 118         if (error)
 119                 goto dput_and_out;
 120
 121         error = locks_verify_truncate(inode, NULL, length);
 122         if (!error) {
 123                 DQUOT_INIT(inode);
 124                 error = do_truncate(nd.dentry, length);
 125         }
 126         put_write_access(inode);
 127         unlock_kernel();
 128
 129 dput_and_out:
 130         path_release(&nd);
 131 out:
 132         return error;
 133 }
 134
 135 asmlinkage long sys_truncate(const char * path, unsigned long length)
 136 {
 137         return do_sys_truncate(path, length);
 138 }
 139
 140 static inline long do_sys_ftruncate(unsigned int fd, loff_t length)
 141 {
 142         struct inode * inode;
 143         struct dentry *dentry;
 144         struct file * file;
 145         int error;
 146
 147         error = -EINVAL;
 148         if (length < 0)
 149                 goto out;
 150         error = -EBADF;
 151         file = fget(fd);
 152         if (!file)
 153                 goto out;
 154         dentry = file->f_dentry;
 155         inode = dentry->d_inode;
 156         error = -EACCES;
 157         if (S_ISDIR(inode->i_mode) || !(file->f_mode & FMODE_WRITE))
 158                 goto out_putf;
 159         error = -EPERM;
 160         if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
 161                 goto out_putf;
 162
 163         lock_kernel();
 164         error = locks_verify_truncate(inode, file, length);
 165         if (!error)
 166                 error = do_truncate(dentry, length);
 167         unlock_kernel();
 168 out_putf:
 169         fput(file);
 170 out:
 171         return error;
 172 }
 173
 174 asmlinkage long sys_ftruncate(unsigned int fd, unsigned long length)
 175 {
 176         return do_sys_ftruncate(fd, length);
 177 }
 178
 179 /* LFS versions of truncate are only needed on 32 bit machines */
 180 #if BITS_PER_LONG == 32
 181 asmlinkage long sys_truncate64(const char * path, loff_t length)
 182 {
 183         return do_sys_truncate(path, length);
 184 }
 185
 186 asmlinkage long sys_ftruncate64(unsigned int fd, loff_t length)
 187 {
 188         return do_sys_ftruncate(fd, length);
 189 }
 190 #endif
 191
 192 #if !(defined(__alpha__) || defined(__ia64__))
 193
 194 /*
 195  * sys_utime() can be implemented in user-level using sys_utimes().
 196  * Is this for backwards compatibility?  If so, why not move it
 197  * into the appropriate arch directory (for those architectures that
 198  * need it).
 199  */
 200
 201 /* If times==NULL, set access and modification to current time,
 202  * must be owner or have write permission.
 203  * Else, update from *times, must be owner or super user.
 204  */
 205 asmlinkage long sys_utime(char * filename, struct utimbuf * times)
 206 {
 207         int error;
 208         struct nameidata nd;
 209         struct inode * inode;
 210         struct iattr newattrs;
 211
 212         error = user_path_walk(filename, &nd);
 213         if (error)
 214                 goto out;
 215         inode = nd.dentry->d_inode;
 216
 217         error = -EROFS;
 218         if (IS_RDONLY(inode))
 219                 goto dput_and_out;
 220
 221         /* Don't worry, the checks are done in inode_change_ok() */
 222         newattrs.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_ATIME;
 223         if (times) {
 224                 error = get_user(newattrs.ia_atime, &times->actime);
 225                 if (!error)
 226                         error = get_user(newattrs.ia_mtime, &times->modtime);
 227                 if (error)
 228                         goto dput_and_out;
 229
 230                 newattrs.ia_valid |= ATTR_ATIME_SET | ATTR_MTIME_SET;
 231         } else {
 232                 if (current->fsuid != inode->i_uid &&
 233                     (error = permission(inode,MAY_WRITE)) != 0)
 234                         goto dput_and_out;
 235         }
 236         error = notify_change(nd.dentry, &newattrs);
 237 dput_and_out:
 238         path_release(&nd);
 239 out:
 240         return error;
 241 }
 242
 243 #endif
 244
 245 /* If times==NULL, set access and modification to current time,
 246  * must be owner or have write permission.
 247  * Else, update from *times, must be owner or super user.
 248  */
 249 asmlinkage long sys_utimes(char * filename, struct timeval * utimes)
 250 {
 251         int error;
 252         struct nameidata nd;
 253         struct inode * inode;
 254         struct iattr newattrs;
 255
 256         error = user_path_walk(filename, &nd);
 257
 258         if (error)
 259                 goto out;
 260         inode = nd.dentry->d_inode;
 261
 262         error = -EROFS;
 263         if (IS_RDONLY(inode))
 264                 goto dput_and_out;
 265
 266         /* Don't worry, the checks are done in inode_change_ok() */
 267         newattrs.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_ATIME;
 268         if (utimes) {
 269                 struct timeval times[2];
 270                 error = -EFAULT;
 271                 if (copy_from_user(&times, utimes, sizeof(times)))
 272                         goto dput_and_out;
 273                 newattrs.ia_atime = times[0].tv_sec;
 274                 newattrs.ia_mtime = times[1].tv_sec;
 275                 newattrs.ia_valid |= ATTR_ATIME_SET | ATTR_MTIME_SET;
 276         } else {
 277                 if ((error = permission(inode,MAY_WRITE)) != 0)
 278                         goto dput_and_out;
 279         }
 280         error = notify_change(nd.dentry, &newattrs);
 281 dput_and_out:
 282         path_release(&nd);
 283 out:
 284         return error;
 285 }
 286
 287 /*
 288  * access() needs to use the real uid/gid, not the effective uid/gid.
 289  * We do this by temporarily clearing all FS-related capabilities and
 290  * switching the fsuid/fsgid around to the real ones.
 291  */
 292 asmlinkage long sys_access(const char * filename, int mode)
 293 {
 294         struct nameidata nd;
 295         int old_fsuid, old_fsgid;
 296         kernel_cap_t old_cap;
 297         int res;
 298
 299         if (mode & ~S_IRWXO)    /* where's F_OK, X_OK, W_OK, R_OK? */
 300                 return -EINVAL;
 301
 302         old_fsuid = current->fsuid;
 303         old_fsgid = current->fsgid;
 304         old_cap = current->cap_effective;
 305
 306         current->fsuid = current->uid;
 307         current->fsgid = current->gid;
 308
 309         /* Clear the capabilities if we switch to a non-root user */
 310         if (current->uid)
 311                 cap_clear(current->cap_effective);
 312         else
 313                 current->cap_effective = current->cap_permitted;
 314
 315         res = user_path_walk(filename, &nd);
 316         if (!res) {
 317                 res = permission(nd.dentry->d_inode, mode);
 318                 /* SuS v2 requires we report a read only fs too */
 319                 if(!res && (mode & S_IWOTH) && IS_RDONLY(nd.dentry->d_inode))
 320                         res = -EROFS;
 321                 path_release(&nd);
 322         }
 323
 324         current->fsuid = old_fsuid;
 325         current->fsgid = old_fsgid;
 326         current->cap_effective = old_cap;
 327
 328         return res;
 329 }
 330
 331 asmlinkage long sys_chdir(const char * filename)
 332 {
 333         int error;
 334         struct nameidata nd;
 335         char *name;
 336
 337         lock_kernel();
 338
 339         name = getname(filename);
 340         error = PTR_ERR(name);
 341         if (IS_ERR(name))
 342                 goto out;
 343
 344         error = 0;
 345         if (path_init(name,LOOKUP_POSITIVE|LOOKUP_FOLLOW|LOOKUP_DIRECTORY,&nd))
 346                 error = path_walk(name, &nd);
 347         putname(name);
 348         if (error)
 349                 goto out;
 350
 351         error = permission(nd.dentry->d_inode,MAY_EXEC);
 352         if (error)
 353                 goto dput_and_out;
 354
 355         set_fs_pwd(current->fs, nd.mnt, nd.dentry);
 356
 357 dput_and_out:
 358         path_release(&nd);
 359 out:
 360         unlock_kernel();
 361         return error;
 362 }
 363
 364 asmlinkage long sys_fchdir(unsigned int fd)
 365 {
 366         struct file *file;
 367         struct dentry *dentry;
 368         struct inode *inode;
 369         struct vfsmount *mnt;
 370         int error;
 371
 372         error = -EBADF;
 373         file = fget(fd);
 374         if (!file)
 375                 goto out;
 376
 377         dentry = file->f_dentry;
 378         mnt = file->f_vfsmnt;
 379         inode = dentry->d_inode;
 380
 381         error = -ENOTDIR;
 382         if (!S_ISDIR(inode->i_mode))
 383                 goto out_putf;
 384
 385         lock_kernel();
 386         error = permission(inode, MAY_EXEC);
 387         if (!error)
 388                 set_fs_pwd(current->fs, mnt, dentry);
 389         unlock_kernel();
 390 out_putf:
 391         fput(file);
 392 out:
 393         return error;
 394 }
 395
 396 asmlinkage long sys_chroot(const char * filename)
 397 {
 398         int error;
 399         struct nameidata nd;
 400         char *name;
 401
 402         lock_kernel();
 403
 404         name = getname(filename);
 405         error = PTR_ERR(name);
 406         if (IS_ERR(name))
 407                 goto out;
 408
 409         path_init(name, LOOKUP_POSITIVE | LOOKUP_FOLLOW |
 410                       LOOKUP_DIRECTORY | LOOKUP_NOALT, &nd);
 411         error = path_walk(name, &nd);
 412         putname(name);
 413         if (error)
 414                 goto out;
 415
 416         error = permission(nd.dentry->d_inode,MAY_EXEC);
 417         if (error)
 418                 goto dput_and_out;
 419
 420         error = -EPERM;
 421         if (!capable(CAP_SYS_CHROOT))
 422                 goto dput_and_out;
 423
 424         set_fs_root(current->fs, nd.mnt, nd.dentry);
 425         set_fs_altroot();
 426         error = 0;
 427 dput_and_out:
 428         path_release(&nd);
 429 out:
 430         unlock_kernel();
 431         return error;
 432 }
 433
 434 asmlinkage long sys_fchmod(unsigned int fd, mode_t mode)
 435 {
 436         struct inode * inode;
 437         struct dentry * dentry;
 438         struct file * file;
 439         int err = -EBADF;
 440         struct iattr newattrs;
 441
 442         file = fget(fd);
 443         if (!file)
 444                 goto out;
 445
 446         dentry = file->f_dentry;
 447         inode = dentry->d_inode;
 448
 449         err = -EROFS;
 450         if (IS_RDONLY(inode))
 451                 goto out_putf;
 452         err = -EPERM;
 453         if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
 454                 goto out_putf;
 455         if (mode == (mode_t) -1)
 456                 mode = inode->i_mode;
 457         newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
 458         newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
 459         lock_kernel();
 460         err = notify_change(dentry, &newattrs);
 461         unlock_kernel();
 462
 463 out_putf:
 464         fput(file);
 465 out:
 466         return err;
 467 }
 468
 469 asmlinkage long sys_chmod(const char * filename, mode_t mode)
 470 {
 471         struct nameidata nd;
 472         struct inode * inode;
 473         int error;
 474         struct iattr newattrs;
 475
 476         error = user_path_walk(filename, &nd);
 477         if (error)
 478                 goto out;
 479         inode = nd.dentry->d_inode;
 480
 481         error = -EROFS;
 482         if (IS_RDONLY(inode))
 483                 goto dput_and_out;
 484
 485         error = -EPERM;
 486         if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
 487                 goto dput_and_out;
 488
 489         if (mode == (mode_t) -1)
 490                 mode = inode->i_mode;
 491         newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
 492         newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
 493         error = notify_change(nd.dentry, &newattrs);
 494
 495 dput_and_out:
 496         path_release(&nd);
 497 out:
 498         return error;
 499 }
 500
 501 static int chown_common(struct dentry * dentry, uid_t user, gid_t group)
 502 {
 503         struct inode * inode;
 504         int error;
 505         struct iattr newattrs;
 506
 507         error = -ENOENT;
 508         if (!(inode = dentry->d_inode)) {
 509                 printk("chown_common: NULL inode\n");
 510                 goto out;
 511         }
 512         error = -EROFS;
 513         if (IS_RDONLY(inode))
 514                 goto out;
 515         error = -EPERM;
 516         if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
 517                 goto out;
 518         if (user == (uid_t) -1)
 519                 user = inode->i_uid;
 520         if (group == (gid_t) -1)
 521                 group = inode->i_gid;
 522         newattrs.ia_mode = inode->i_mode;
 523         newattrs.ia_uid = user;
 524         newattrs.ia_gid = group;
 525         newattrs.ia_valid =  ATTR_UID | ATTR_GID | ATTR_CTIME;
 526         /*
 527          * If the user or group of a non-directory has been changed by a
 528          * non-root user, remove the setuid bit.
 529          * 19981026     David C Niemi <niemi@tux.org>
 530          *
 531          * Changed this to apply to all users, including root, to avoid
 532          * some races. This is the behavior we had in 2.0. The check for
 533          * non-root was definitely wrong for 2.2 anyway, as it should
 534          * have been using CAP_FSETID rather than fsuid -- 19990830 SD.
 535          */
 536         if ((inode->i_mode & S_ISUID) == S_ISUID &&
 537                 !S_ISDIR(inode->i_mode))
 538         {
 539                 newattrs.ia_mode &= ~S_ISUID;
 540                 newattrs.ia_valid |= ATTR_MODE;
 541         }
 542         /*
 543          * Likewise, if the user or group of a non-directory has been changed
 544          * by a non-root user, remove the setgid bit UNLESS there is no group
 545          * execute bit (this would be a file marked for mandatory locking).
 546          * 19981026     David C Niemi <niemi@tux.org>
 547          *
 548          * Removed the fsuid check (see the comment above) -- 19990830 SD.
 549          */
 550         if (((inode->i_mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP))
 551                 && !S_ISDIR(inode->i_mode))
 552         {
 553                 newattrs.ia_mode &= ~S_ISGID;
 554                 newattrs.ia_valid |= ATTR_MODE;
 555         }
 556         error = DQUOT_TRANSFER(dentry, &newattrs);
 557 out:
 558         return error;
 559 }
 560
 561 asmlinkage long sys_chown(const char * filename, uid_t user, gid_t group)
 562 {
 563         struct nameidata nd;
 564         int error;
 565
 566         error = user_path_walk(filename, &nd);
 567         if (!error) {
 568                 error = chown_common(nd.dentry, user, group);
 569                 path_release(&nd);
 570         }
 571         return error;
 572 }
 573
 574 asmlinkage long sys_lchown(const char * filename, uid_t user, gid_t group)
 575 {
 576         struct nameidata nd;
 577         int error;
 578
 579         error = user_path_walk_link(filename, &nd);
 580         if (!error) {
 581                 error = chown_common(nd.dentry, user, group);
 582                 path_release(&nd);
 583         }
 584         return error;
 585 }
 586
 587
 588 asmlinkage long sys_fchown(unsigned int fd, uid_t user, gid_t group)
 589 {
 590         struct file * file;
 591         int error = -EBADF;
 592
 593         file = fget(fd);
 594         if (file) {
 595                 error = chown_common(file->f_dentry, user, group);
 596                 fput(file);
 597         }
 598         return error;
 599 }
 600
 601 /*
 602  * Note that while the flag value (low two bits) for sys_open means:
 603  *      00 - read-only
 604  *      01 - write-only
 605  *      10 - read-write
 606  *      11 - special
 607  * it is changed into
 608  *      00 - no permissions needed
 609  *      01 - read-permission
 610  *      10 - write-permission
 611  *      11 - read-write
 612  * for the internal routines (ie open_namei()/follow_link() etc). 00 is
 613  * used by symlinks.
 614  */
 615 struct file *filp_open(const char * filename, int flags, int mode)
 616 {
 617         int namei_flags, error;
 618         struct nameidata nd;
 619
 620         namei_flags = flags;
 621         if ((namei_flags+1) & O_ACCMODE)
 622                 namei_flags++;
 623         if (namei_flags & O_TRUNC)
 624                 namei_flags |= 2;
 625
 626         error = open_namei(filename, namei_flags, mode, &nd);
 627         if (!error)
 628                 return dentry_open(nd.dentry, nd.mnt, flags);
 629
 630         return ERR_PTR(error);
 631 }
 632
 633 struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags)
 634 {
 635         struct file * f;
 636         struct inode *inode;
 637         int error;
 638
 639         error = -ENFILE;
 640         f = get_empty_filp();
 641         if (!f)
 642                 goto cleanup_dentry;
 643         f->f_flags = flags;
 644         f->f_mode = (flags+1) & O_ACCMODE;
 645         inode = dentry->d_inode;
 646         if (f->f_mode & FMODE_WRITE) {
 647                 error = get_write_access(inode);
 648                 if (error)
 649                         goto cleanup_file;
 650         }
 651
 652         f->f_dentry = dentry;
 653         f->f_vfsmnt = mnt;
 654         f->f_pos = 0;
 655         f->f_reada = 0;
 656         f->f_op = inode->i_fop;
 657         if (inode->i_sb)
 658                 file_move(f, &inode->i_sb->s_files);
 659         if (f->f_op && f->f_op->open) {
 660                 error = f->f_op->open(inode,f);
 661                 if (error)
 662                         goto cleanup_all;
 663         }
 664         f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
 665
 666         return f;
 667
 668 cleanup_all:
 669         if (f->f_mode & FMODE_WRITE)
 670                 put_write_access(inode);
 671         f->f_dentry = NULL;
 672         f->f_vfsmnt = NULL;
 673 cleanup_file:
 674         put_filp(f);
 675 cleanup_dentry:
 676         dput(dentry);
 677         mntput(mnt);
 678         return ERR_PTR(error);
 679 }
 680
 681 /*
 682  * Find an empty file descriptor entry, and mark it busy.
 683  */
 684 int get_unused_fd(void)
 685 {
 686         struct files_struct * files = current->files;
 687         int fd, error;
 688
 689         error = -EMFILE;
 690         write_lock(&files->file_lock);
 691
 692 repeat:
 693         fd = find_next_zero_bit(files->open_fds,
 694                                 current->files->max_fdset,
 695                                 files->next_fd);
 696
 697         /*
 698          * N.B. For clone tasks sharing a files structure, this test
 699          * will limit the total number of files that can be opened.
 700          */
 701         if (fd >= current->rlim[RLIMIT_NOFILE].rlim_cur)
 702                 goto out;
 703
 704         /* Do we need to expand the fdset array? */
 705         if (fd >= current->files->max_fdset) {
 706                 error = expand_fdset(files, fd);
 707                 if (!error) {
 708                         error = -EMFILE;
 709                         goto repeat;
 710                 }
 711                 goto out;
 712         }
 713
 714         /*
 715          * Check whether we need to expand the fd array.
 716          */
 717         if (fd >= files->max_fds) {
 718                 error = expand_fd_array(files, fd);
 719                 if (!error) {
 720                         error = -EMFILE;
 721                         goto repeat;
 722                 }
 723                 goto out;
 724         }
 725
 726         FD_SET(fd, files->open_fds);
 727         FD_CLR(fd, files->close_on_exec);
 728         files->next_fd = fd + 1;
 729 #if 1
 730         /* Sanity check */
 731         if (files->fd[fd] != NULL) {
 732                 printk("get_unused_fd: slot %d not NULL!\n", fd);
 733                 files->fd[fd] = NULL;
 734         }
 735 #endif
 736         error = fd;
 737
 738 out:
 739         write_unlock(&files->file_lock);
 740         return error;
 741 }
 742
 743 inline void __put_unused_fd(struct files_struct *files, unsigned int fd)
 744 {
 745         FD_CLR(fd, files->open_fds);
 746         if (fd < files->next_fd)
 747                 files->next_fd = fd;
 748 }
 749
 750 inline void put_unused_fd(unsigned int fd)
 751 {
 752         struct files_struct *files = current->files;
 753
 754         write_lock(&files->file_lock);
 755         __put_unused_fd(files, fd);
 756         write_unlock(&files->file_lock);
 757 }
 758
 759 asmlinkage long sys_open(const char * filename, int flags, int mode)
 760 {
 761         char * tmp;
 762         int fd, error;
 763
 764 #if BITS_PER_LONG != 32
 765         flags |= O_LARGEFILE;
 766 #endif
 767         tmp = getname(filename);
 768         fd = PTR_ERR(tmp);
 769         if (!IS_ERR(tmp)) {
 770                 fd = get_unused_fd();
 771                 if (fd >= 0) {
 772                         struct file * f;
 773                         lock_kernel();
 774                         f = filp_open(tmp, flags, mode);
 775                         unlock_kernel();
 776                         error = PTR_ERR(f);
 777                         if (IS_ERR(f))
 778                                 goto out_error;
 779                         fd_install(fd, f);
 780                 }
 781 out:
 782                 putname(tmp);
 783         }
 784         return fd;
 785
 786 out_error:
 787         put_unused_fd(fd);
 788         fd = error;
 789         goto out;
 790 }
 791
 792 #ifndef __alpha__
 793
 794 /*
 795  * For backward compatibility?  Maybe this should be moved
 796  * into arch/i386 instead?
 797  */
 798 asmlinkage long sys_creat(const char * pathname, int mode)
 799 {
 800         return sys_open(pathname, O_CREAT | O_WRONLY | O_TRUNC, mode);
 801 }
 802
 803 #endif
 804
 805 /*
 806  * "id" is the POSIX thread ID. We use the
 807  * files pointer for this..
 808  */
 809 int filp_close(struct file *filp, fl_owner_t id)
 810 {
 811         int retval;
 812
 813         if (!file_count(filp)) {
 814                 printk("VFS: Close: file count is 0\n");
 815                 return 0;
 816         }
 817         retval = 0;
 818         if (filp->f_op && filp->f_op->flush)
 819                 retval = filp->f_op->flush(filp);
 820         locks_remove_posix(filp, id);
 821         fput(filp);
 822         return retval;
 823 }
 824
 825 /*
 826  * Careful here! We test whether the file pointer is NULL before
 827  * releasing the fd. This ensures that one clone task can't release
 828  * an fd while another clone is opening it.
 829  *
 830  * The "release" argument tells us whether or not to mark the fd as free
 831  * or not in the open-files bitmap.  dup2 uses this to retain the fd
 832  * without races.
 833  */
 834 int do_close(unsigned int fd, int release)
 835 {
 836         int error;
 837         struct file * filp;
 838         struct files_struct * files = current->files;
 839
 840         error = -EBADF;
 841         write_lock(&files->file_lock);
 842         filp = frip(files, fd);
 843         if (!filp)
 844                 goto out_unlock;
 845         FD_CLR(fd, files->close_on_exec);
 846         if (release)
 847                 __put_unused_fd(files, fd);
 848         write_unlock(&files->file_lock);
 849         lock_kernel();
 850         error = filp_close(filp, files);
 851         unlock_kernel();
 852 out:
 853         return error;
 854 out_unlock:
 855         write_unlock(&files->file_lock);
 856         goto out;
 857 }
 858
 859 asmlinkage long sys_close(unsigned int fd)
 860 {
 861         return do_close(fd, 1);
 862 }
 863
 864 /*
 865  * This routine simulates a hangup on the tty, to arrange that users
 866  * are given clean terminals at login time.
 867  */
 868 asmlinkage long sys_vhangup(void)
 869 {
 870         if (capable(CAP_SYS_TTY_CONFIG)) {
 871                 tty_vhangup(current->tty);
 872                 return 0;
 873         }
 874         return -EPERM;
 875 }