fs/stat.c

   1 /*
   2  *  linux/fs/stat.c
   3  *
   4  *  Copyright (C) 1991, 1992  Linus Torvalds
   5  */
   6
   7 #include <linux/export.h>
   8 #include <linux/mm.h>
   9 #include <linux/errno.h>
  10 #include <linux/file.h>
  11 #include <linux/highuid.h>
  12 #include <linux/fs.h>
  13 #include <linux/namei.h>
  14 #include <linux/security.h>
  15 #include <linux/cred.h>
  16 #include <linux/syscalls.h>
  17 #include <linux/pagemap.h>
  18 #include <linux/compat.h>
  19
  20 #include <linux/uaccess.h>
  21 #include <asm/unistd.h>
  22
  23 /**
  24  * generic_fillattr - Fill in the basic attributes from the inode struct
  25  * @inode: Inode to use as the source
  26  * @stat: Where to fill in the attributes
  27  *
  28  * Fill in the basic attributes in the kstat structure from data that's to be
  29  * found on the VFS inode structure.  This is the default if no getattr inode
  30  * operation is supplied.
  31  */
  32 void generic_fillattr(struct inode *inode, struct kstat *stat)
  33 {
  34         stat->dev = inode->i_sb->s_dev;
  35         stat->ino = inode->i_ino;
  36         stat->mode = inode->i_mode;
  37         stat->nlink = inode->i_nlink;
  38         stat->uid = inode->i_uid;
  39         stat->gid = inode->i_gid;
  40         stat->rdev = inode->i_rdev;
  41         stat->size = i_size_read(inode);
  42         stat->atime = inode->i_atime;
  43         stat->mtime = inode->i_mtime;
  44         stat->ctime = inode->i_ctime;
  45         stat->blksize = i_blocksize(inode);
  46         stat->blocks = inode->i_blocks;
  47
  48         if (IS_NOATIME(inode))
  49                 stat->result_mask &= ~STATX_ATIME;
  50         if (IS_AUTOMOUNT(inode))
  51                 stat->attributes |= STATX_ATTR_AUTOMOUNT;
  52 }
  53 EXPORT_SYMBOL(generic_fillattr);
  54
  55 /**
  56  * vfs_getattr_nosec - getattr without security checks
  57  * @path: file to get attributes from
  58  * @stat: structure to return attributes in
  59  * @request_mask: STATX_xxx flags indicating what the caller wants
  60  * @query_flags: Query mode (KSTAT_QUERY_FLAGS)
  61  *
  62  * Get attributes without calling security_inode_getattr.
  63  *
  64  * Currently the only caller other than vfs_getattr is internal to the
  65  * filehandle lookup code, which uses only the inode number and returns no
  66  * attributes to any user.  Any other code probably wants vfs_getattr.
  67  */
  68 int vfs_getattr_nosec(const struct path *path, struct kstat *stat,
  69                       u32 request_mask, unsigned int query_flags)
  70 {
  71         struct inode *inode = d_backing_inode(path->dentry);
  72
  73         memset(stat, 0, sizeof(*stat));
  74         stat->result_mask |= STATX_BASIC_STATS;
  75         request_mask &= STATX_ALL;
  76         query_flags &= KSTAT_QUERY_FLAGS;
  77         if (inode->i_op->getattr)
  78                 return inode->i_op->getattr(path, stat, request_mask,
  79                                             query_flags);
  80
  81         generic_fillattr(inode, stat);
  82         return 0;
  83 }
  84 EXPORT_SYMBOL(vfs_getattr_nosec);
  85
  86 /*
  87  * vfs_getattr - Get the enhanced basic attributes of a file
  88  * @path: The file of interest
  89  * @stat: Where to return the statistics
  90  * @request_mask: STATX_xxx flags indicating what the caller wants
  91  * @query_flags: Query mode (KSTAT_QUERY_FLAGS)
  92  *
  93  * Ask the filesystem for a file's attributes.  The caller must indicate in
  94  * request_mask and query_flags to indicate what they want.
  95  *
  96  * If the file is remote, the filesystem can be forced to update the attributes
  97  * from the backing store by passing AT_STATX_FORCE_SYNC in query_flags or can
  98  * suppress the update by passing AT_STATX_DONT_SYNC.
  99  *
 100  * Bits must have been set in request_mask to indicate which attributes the
 101  * caller wants retrieving.  Any such attribute not requested may be returned
 102  * anyway, but the value may be approximate, and, if remote, may not have been
 103  * synchronised with the server.
 104  *
 105  * 0 will be returned on success, and a -ve error code if unsuccessful.
 106  */
 107 int vfs_getattr(const struct path *path, struct kstat *stat,
 108                 u32 request_mask, unsigned int query_flags)
 109 {
 110         int retval;
 111
 112         retval = security_inode_getattr(path);
 113         if (retval)
 114                 return retval;
 115         return vfs_getattr_nosec(path, stat, request_mask, query_flags);
 116 }
 117 EXPORT_SYMBOL(vfs_getattr);
 118
 119 /**
 120  * vfs_statx_fd - Get the enhanced basic attributes by file descriptor
 121  * @fd: The file descriptor referring to the file of interest
 122  * @stat: The result structure to fill in.
 123  * @request_mask: STATX_xxx flags indicating what the caller wants
 124  * @query_flags: Query mode (KSTAT_QUERY_FLAGS)
 125  *
 126  * This function is a wrapper around vfs_getattr().  The main difference is
 127  * that it uses a file descriptor to determine the file location.
 128  *
 129  * 0 will be returned on success, and a -ve error code if unsuccessful.
 130  */
 131 int vfs_statx_fd(unsigned int fd, struct kstat *stat,
 132                  u32 request_mask, unsigned int query_flags)
 133 {
 134         struct fd f;
 135         int error = -EBADF;
 136
 137         if (query_flags & ~KSTAT_QUERY_FLAGS)
 138                 return -EINVAL;
 139
 140         f = fdget_raw(fd);
 141         if (f.file) {
 142                 error = vfs_getattr(&f.file->f_path, stat,
 143                                     request_mask, query_flags);
 144                 fdput(f);
 145         }
 146         return error;
 147 }
 148 EXPORT_SYMBOL(vfs_statx_fd);
 149
 150 /**
 151  * vfs_statx - Get basic and extra attributes by filename
 152  * @dfd: A file descriptor representing the base dir for a relative filename
 153  * @filename: The name of the file of interest
 154  * @flags: Flags to control the query
 155  * @stat: The result structure to fill in.
 156  * @request_mask: STATX_xxx flags indicating what the caller wants
 157  *
 158  * This function is a wrapper around vfs_getattr().  The main difference is
 159  * that it uses a filename and base directory to determine the file location.
 160  * Additionally, the use of AT_SYMLINK_NOFOLLOW in flags will prevent a symlink
 161  * at the given name from being referenced.
 162  *
 163  * 0 will be returned on success, and a -ve error code if unsuccessful.
 164  */
 165 int vfs_statx(int dfd, const char __user *filename, int flags,
 166               struct kstat *stat, u32 request_mask)
 167 {
 168         struct path path;
 169         int error = -EINVAL;
 170         unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_AUTOMOUNT;
 171
 172         if ((flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT |
 173                        AT_EMPTY_PATH | KSTAT_QUERY_FLAGS)) != 0)
 174                 return -EINVAL;
 175
 176         if (flags & AT_SYMLINK_NOFOLLOW)
 177                 lookup_flags &= ~LOOKUP_FOLLOW;
 178         if (flags & AT_NO_AUTOMOUNT)
 179                 lookup_flags &= ~LOOKUP_AUTOMOUNT;
 180         if (flags & AT_EMPTY_PATH)
 181                 lookup_flags |= LOOKUP_EMPTY;
 182
 183 retry:
 184         error = user_path_at(dfd, filename, lookup_flags, &path);
 185         if (error)
 186                 goto out;
 187
 188         error = vfs_getattr(&path, stat, request_mask, flags);
 189         path_put(&path);
 190         if (retry_estale(error, lookup_flags)) {
 191                 lookup_flags |= LOOKUP_REVAL;
 192                 goto retry;
 193         }
 194 out:
 195         return error;
 196 }
 197 EXPORT_SYMBOL(vfs_statx);
 198
 199
 200 #ifdef __ARCH_WANT_OLD_STAT
 201
 202 /*
 203  * For backward compatibility?  Maybe this should be moved
 204  * into arch/i386 instead?
 205  */
 206 static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf)
 207 {
 208         static int warncount = 5;
 209         struct __old_kernel_stat tmp;
 210
 211         if (warncount > 0) {
 212                 warncount--;
 213                 printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n",
 214                         current->comm);
 215         } else if (warncount < 0) {
 216                 /* it's laughable, but... */
 217                 warncount = 0;
 218         }
 219
 220         memset(&tmp, 0, sizeof(struct __old_kernel_stat));
 221         tmp.st_dev = old_encode_dev(stat->dev);
 222         tmp.st_ino = stat->ino;
 223         if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
 224                 return -EOVERFLOW;
 225         tmp.st_mode = stat->mode;
 226         tmp.st_nlink = stat->nlink;
 227         if (tmp.st_nlink != stat->nlink)
 228                 return -EOVERFLOW;
 229         SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
 230         SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
 231         tmp.st_rdev = old_encode_dev(stat->rdev);
 232 #if BITS_PER_LONG == 32
 233         if (stat->size > MAX_NON_LFS)
 234                 return -EOVERFLOW;
 235 #endif
 236         tmp.st_size = stat->size;
 237         tmp.st_atime = stat->atime.tv_sec;
 238         tmp.st_mtime = stat->mtime.tv_sec;
 239         tmp.st_ctime = stat->ctime.tv_sec;
 240         return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
 241 }
 242
 243 SYSCALL_DEFINE2(stat, const char __user *, filename,
 244                 struct __old_kernel_stat __user *, statbuf)
 245 {
 246         struct kstat stat;
 247         int error;
 248
 249         error = vfs_stat(filename, &stat);
 250         if (error)
 251                 return error;
 252
 253         return cp_old_stat(&stat, statbuf);
 254 }
 255
 256 SYSCALL_DEFINE2(lstat, const char __user *, filename,
 257                 struct __old_kernel_stat __user *, statbuf)
 258 {
 259         struct kstat stat;
 260         int error;
 261
 262         error = vfs_lstat(filename, &stat);
 263         if (error)
 264                 return error;
 265
 266         return cp_old_stat(&stat, statbuf);
 267 }
 268
 269 SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf)
 270 {
 271         struct kstat stat;
 272         int error = vfs_fstat(fd, &stat);
 273
 274         if (!error)
 275                 error = cp_old_stat(&stat, statbuf);
 276
 277         return error;
 278 }
 279
 280 #endif /* __ARCH_WANT_OLD_STAT */
 281
 282 #if BITS_PER_LONG == 32
 283 #  define choose_32_64(a,b) a
 284 #else
 285 #  define choose_32_64(a,b) b
 286 #endif
 287
 288 #define valid_dev(x)  choose_32_64(old_valid_dev(x),true)
 289 #define encode_dev(x) choose_32_64(old_encode_dev,new_encode_dev)(x)
 290
 291 #ifndef INIT_STRUCT_STAT_PADDING
 292 #  define INIT_STRUCT_STAT_PADDING(st) memset(&st, 0, sizeof(st))
 293 #endif
 294
 295 static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf)
 296 {
 297         struct stat tmp;
 298
 299         if (!valid_dev(stat->dev) || !valid_dev(stat->rdev))
 300                 return -EOVERFLOW;
 301 #if BITS_PER_LONG == 32
 302         if (stat->size > MAX_NON_LFS)
 303                 return -EOVERFLOW;
 304 #endif
 305
 306         INIT_STRUCT_STAT_PADDING(tmp);
 307         tmp.st_dev = encode_dev(stat->dev);
 308         tmp.st_ino = stat->ino;
 309         if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
 310                 return -EOVERFLOW;
 311         tmp.st_mode = stat->mode;
 312         tmp.st_nlink = stat->nlink;
 313         if (tmp.st_nlink != stat->nlink)
 314                 return -EOVERFLOW;
 315         SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
 316         SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
 317         tmp.st_rdev = encode_dev(stat->rdev);
 318         tmp.st_size = stat->size;
 319         tmp.st_atime = stat->atime.tv_sec;
 320         tmp.st_mtime = stat->mtime.tv_sec;
 321         tmp.st_ctime = stat->ctime.tv_sec;
 322 #ifdef STAT_HAVE_NSEC
 323         tmp.st_atime_nsec = stat->atime.tv_nsec;
 324         tmp.st_mtime_nsec = stat->mtime.tv_nsec;
 325         tmp.st_ctime_nsec = stat->ctime.tv_nsec;
 326 #endif
 327         tmp.st_blocks = stat->blocks;
 328         tmp.st_blksize = stat->blksize;
 329         return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
 330 }
 331
 332 SYSCALL_DEFINE2(newstat, const char __user *, filename,
 333                 struct stat __user *, statbuf)
 334 {
 335         struct kstat stat;
 336         int error = vfs_stat(filename, &stat);
 337
 338         if (error)
 339                 return error;
 340         return cp_new_stat(&stat, statbuf);
 341 }
 342
 343 SYSCALL_DEFINE2(newlstat, const char __user *, filename,
 344                 struct stat __user *, statbuf)
 345 {
 346         struct kstat stat;
 347         int error;
 348
 349         error = vfs_lstat(filename, &stat);
 350         if (error)
 351                 return error;
 352
 353         return cp_new_stat(&stat, statbuf);
 354 }
 355
 356 #if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT)
 357 SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename,
 358                 struct stat __user *, statbuf, int, flag)
 359 {
 360         struct kstat stat;
 361         int error;
 362
 363         error = vfs_fstatat(dfd, filename, &stat, flag);
 364         if (error)
 365                 return error;
 366         return cp_new_stat(&stat, statbuf);
 367 }
 368 #endif
 369
 370 SYSCALL_DEFINE2(newfstat, unsigned int, fd, struct stat __user *, statbuf)
 371 {
 372         struct kstat stat;
 373         int error = vfs_fstat(fd, &stat);
 374
 375         if (!error)
 376                 error = cp_new_stat(&stat, statbuf);
 377
 378         return error;
 379 }
 380
 381 SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname,
 382                 char __user *, buf, int, bufsiz)
 383 {
 384         struct path path;
 385         int error;
 386         int empty = 0;
 387         unsigned int lookup_flags = LOOKUP_EMPTY;
 388
 389         if (bufsiz <= 0)
 390                 return -EINVAL;
 391
 392 retry:
 393         error = user_path_at_empty(dfd, pathname, lookup_flags, &path, &empty);
 394         if (!error) {
 395                 struct inode *inode = d_backing_inode(path.dentry);
 396
 397                 error = empty ? -ENOENT : -EINVAL;
 398                 /*
 399                  * AFS mountpoints allow readlink(2) but are not symlinks
 400                  */
 401                 if (d_is_symlink(path.dentry) || inode->i_op->readlink) {
 402                         error = security_inode_readlink(path.dentry);
 403                         if (!error) {
 404                                 touch_atime(&path);
 405                                 error = vfs_readlink(path.dentry, buf, bufsiz);
 406                         }
 407                 }
 408                 path_put(&path);
 409                 if (retry_estale(error, lookup_flags)) {
 410                         lookup_flags |= LOOKUP_REVAL;
 411                         goto retry;
 412                 }
 413         }
 414         return error;
 415 }
 416
 417 SYSCALL_DEFINE3(readlink, const char __user *, path, char __user *, buf,
 418                 int, bufsiz)
 419 {
 420         return sys_readlinkat(AT_FDCWD, path, buf, bufsiz);
 421 }
 422
 423
 424 /* ---------- LFS-64 ----------- */
 425 #if defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_COMPAT_STAT64)
 426
 427 #ifndef INIT_STRUCT_STAT64_PADDING
 428 #  define INIT_STRUCT_STAT64_PADDING(st) memset(&st, 0, sizeof(st))
 429 #endif
 430
 431 static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf)
 432 {
 433         struct stat64 tmp;
 434
 435         INIT_STRUCT_STAT64_PADDING(tmp);
 436 #ifdef CONFIG_MIPS
 437         /* mips has weird padding, so we don't get 64 bits there */
 438         tmp.st_dev = new_encode_dev(stat->dev);
 439         tmp.st_rdev = new_encode_dev(stat->rdev);
 440 #else
 441         tmp.st_dev = huge_encode_dev(stat->dev);
 442         tmp.st_rdev = huge_encode_dev(stat->rdev);
 443 #endif
 444         tmp.st_ino = stat->ino;
 445         if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
 446                 return -EOVERFLOW;
 447 #ifdef STAT64_HAS_BROKEN_ST_INO
 448         tmp.__st_ino = stat->ino;
 449 #endif
 450         tmp.st_mode = stat->mode;
 451         tmp.st_nlink = stat->nlink;
 452         tmp.st_uid = from_kuid_munged(current_user_ns(), stat->uid);
 453         tmp.st_gid = from_kgid_munged(current_user_ns(), stat->gid);
 454         tmp.st_atime = stat->atime.tv_sec;
 455         tmp.st_atime_nsec = stat->atime.tv_nsec;
 456         tmp.st_mtime = stat->mtime.tv_sec;
 457         tmp.st_mtime_nsec = stat->mtime.tv_nsec;
 458         tmp.st_ctime = stat->ctime.tv_sec;
 459         tmp.st_ctime_nsec = stat->ctime.tv_nsec;
 460         tmp.st_size = stat->size;
 461         tmp.st_blocks = stat->blocks;
 462         tmp.st_blksize = stat->blksize;
 463         return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
 464 }
 465
 466 SYSCALL_DEFINE2(stat64, const char __user *, filename,
 467                 struct stat64 __user *, statbuf)
 468 {
 469         struct kstat stat;
 470         int error = vfs_stat(filename, &stat);
 471
 472         if (!error)
 473                 error = cp_new_stat64(&stat, statbuf);
 474
 475         return error;
 476 }
 477
 478 SYSCALL_DEFINE2(lstat64, const char __user *, filename,
 479                 struct stat64 __user *, statbuf)
 480 {
 481         struct kstat stat;
 482         int error = vfs_lstat(filename, &stat);
 483
 484         if (!error)
 485                 error = cp_new_stat64(&stat, statbuf);
 486
 487         return error;
 488 }
 489
 490 SYSCALL_DEFINE2(fstat64, unsigned long, fd, struct stat64 __user *, statbuf)
 491 {
 492         struct kstat stat;
 493         int error = vfs_fstat(fd, &stat);
 494
 495         if (!error)
 496                 error = cp_new_stat64(&stat, statbuf);
 497
 498         return error;
 499 }
 500
 501 SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename,
 502                 struct stat64 __user *, statbuf, int, flag)
 503 {
 504         struct kstat stat;
 505         int error;
 506
 507         error = vfs_fstatat(dfd, filename, &stat, flag);
 508         if (error)
 509                 return error;
 510         return cp_new_stat64(&stat, statbuf);
 511 }
 512 #endif /* __ARCH_WANT_STAT64 || __ARCH_WANT_COMPAT_STAT64 */
 513
 514 static noinline_for_stack int
 515 cp_statx(const struct kstat *stat, struct statx __user *buffer)
 516 {
 517         struct statx tmp;
 518
 519         memset(&tmp, 0, sizeof(tmp));
 520
 521         tmp.stx_mask = stat->result_mask;
 522         tmp.stx_blksize = stat->blksize;
 523         tmp.stx_attributes = stat->attributes;
 524         tmp.stx_nlink = stat->nlink;
 525         tmp.stx_uid = from_kuid_munged(current_user_ns(), stat->uid);
 526         tmp.stx_gid = from_kgid_munged(current_user_ns(), stat->gid);
 527         tmp.stx_mode = stat->mode;
 528         tmp.stx_ino = stat->ino;
 529         tmp.stx_size = stat->size;
 530         tmp.stx_blocks = stat->blocks;
 531         tmp.stx_attributes_mask = stat->attributes_mask;
 532         tmp.stx_atime.tv_sec = stat->atime.tv_sec;
 533         tmp.stx_atime.tv_nsec = stat->atime.tv_nsec;
 534         tmp.stx_btime.tv_sec = stat->btime.tv_sec;
 535         tmp.stx_btime.tv_nsec = stat->btime.tv_nsec;
 536         tmp.stx_ctime.tv_sec = stat->ctime.tv_sec;
 537         tmp.stx_ctime.tv_nsec = stat->ctime.tv_nsec;
 538         tmp.stx_mtime.tv_sec = stat->mtime.tv_sec;
 539         tmp.stx_mtime.tv_nsec = stat->mtime.tv_nsec;
 540         tmp.stx_rdev_major = MAJOR(stat->rdev);
 541         tmp.stx_rdev_minor = MINOR(stat->rdev);
 542         tmp.stx_dev_major = MAJOR(stat->dev);
 543         tmp.stx_dev_minor = MINOR(stat->dev);
 544
 545         return copy_to_user(buffer, &tmp, sizeof(tmp)) ? -EFAULT : 0;
 546 }
 547
 548 /**
 549  * sys_statx - System call to get enhanced stats
 550  * @dfd: Base directory to pathwalk from *or* fd to stat.
 551  * @filename: File to stat or "" with AT_EMPTY_PATH
 552  * @flags: AT_* flags to control pathwalk.
 553  * @mask: Parts of statx struct actually required.
 554  * @buffer: Result buffer.
 555  *
 556  * Note that fstat() can be emulated by setting dfd to the fd of interest,
 557  * supplying "" as the filename and setting AT_EMPTY_PATH in the flags.
 558  */
 559 SYSCALL_DEFINE5(statx,
 560                 int, dfd, const char __user *, filename, unsigned, flags,
 561                 unsigned int, mask,
 562                 struct statx __user *, buffer)
 563 {
 564         struct kstat stat;
 565         int error;
 566
 567         if (mask & STATX__RESERVED)
 568                 return -EINVAL;
 569         if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_SYNC_TYPE)
 570                 return -EINVAL;
 571
 572         error = vfs_statx(dfd, filename, flags, &stat, mask);
 573         if (error)
 574                 return error;
 575
 576         return cp_statx(&stat, buffer);
 577 }
 578
 579 #ifdef CONFIG_COMPAT
 580 static int cp_compat_stat(struct kstat *stat, struct compat_stat __user *ubuf)
 581 {
 582         struct compat_stat tmp;
 583
 584         if (!old_valid_dev(stat->dev) || !old_valid_dev(stat->rdev))
 585                 return -EOVERFLOW;
 586
 587         memset(&tmp, 0, sizeof(tmp));
 588         tmp.st_dev = old_encode_dev(stat->dev);
 589         tmp.st_ino = stat->ino;
 590         if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
 591                 return -EOVERFLOW;
 592         tmp.st_mode = stat->mode;
 593         tmp.st_nlink = stat->nlink;
 594         if (tmp.st_nlink != stat->nlink)
 595                 return -EOVERFLOW;
 596         SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
 597         SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
 598         tmp.st_rdev = old_encode_dev(stat->rdev);
 599         if ((u64) stat->size > MAX_NON_LFS)
 600                 return -EOVERFLOW;
 601         tmp.st_size = stat->size;
 602         tmp.st_atime = stat->atime.tv_sec;
 603         tmp.st_atime_nsec = stat->atime.tv_nsec;
 604         tmp.st_mtime = stat->mtime.tv_sec;
 605         tmp.st_mtime_nsec = stat->mtime.tv_nsec;
 606         tmp.st_ctime = stat->ctime.tv_sec;
 607         tmp.st_ctime_nsec = stat->ctime.tv_nsec;
 608         tmp.st_blocks = stat->blocks;
 609         tmp.st_blksize = stat->blksize;
 610         return copy_to_user(ubuf, &tmp, sizeof(tmp)) ? -EFAULT : 0;
 611 }
 612
 613 COMPAT_SYSCALL_DEFINE2(newstat, const char __user *, filename,
 614                        struct compat_stat __user *, statbuf)
 615 {
 616         struct kstat stat;
 617         int error;
 618
 619         error = vfs_stat(filename, &stat);
 620         if (error)
 621                 return error;
 622         return cp_compat_stat(&stat, statbuf);
 623 }
 624
 625 COMPAT_SYSCALL_DEFINE2(newlstat, const char __user *, filename,
 626                        struct compat_stat __user *, statbuf)
 627 {
 628         struct kstat stat;
 629         int error;
 630
 631         error = vfs_lstat(filename, &stat);
 632         if (error)
 633                 return error;
 634         return cp_compat_stat(&stat, statbuf);
 635 }
 636
 637 #ifndef __ARCH_WANT_STAT64
 638 COMPAT_SYSCALL_DEFINE4(newfstatat, unsigned int, dfd,
 639                        const char __user *, filename,
 640                        struct compat_stat __user *, statbuf, int, flag)
 641 {
 642         struct kstat stat;
 643         int error;
 644
 645         error = vfs_fstatat(dfd, filename, &stat, flag);
 646         if (error)
 647                 return error;
 648         return cp_compat_stat(&stat, statbuf);
 649 }
 650 #endif
 651
 652 COMPAT_SYSCALL_DEFINE2(newfstat, unsigned int, fd,
 653                        struct compat_stat __user *, statbuf)
 654 {
 655         struct kstat stat;
 656         int error = vfs_fstat(fd, &stat);
 657
 658         if (!error)
 659                 error = cp_compat_stat(&stat, statbuf);
 660         return error;
 661 }
 662 #endif
 663
 664 /* Caller is here responsible for sufficient locking (ie. inode->i_lock) */
 665 void __inode_add_bytes(struct inode *inode, loff_t bytes)
 666 {
 667         inode->i_blocks += bytes >> 9;
 668         bytes &= 511;
 669         inode->i_bytes += bytes;
 670         if (inode->i_bytes >= 512) {
 671                 inode->i_blocks++;
 672                 inode->i_bytes -= 512;
 673         }
 674 }
 675 EXPORT_SYMBOL(__inode_add_bytes);
 676
 677 void inode_add_bytes(struct inode *inode, loff_t bytes)
 678 {
 679         spin_lock(&inode->i_lock);
 680         __inode_add_bytes(inode, bytes);
 681         spin_unlock(&inode->i_lock);
 682 }
 683
 684 EXPORT_SYMBOL(inode_add_bytes);
 685
 686 void __inode_sub_bytes(struct inode *inode, loff_t bytes)
 687 {
 688         inode->i_blocks -= bytes >> 9;
 689         bytes &= 511;
 690         if (inode->i_bytes < bytes) {
 691                 inode->i_blocks--;
 692                 inode->i_bytes += 512;
 693         }
 694         inode->i_bytes -= bytes;
 695 }
 696
 697 EXPORT_SYMBOL(__inode_sub_bytes);
 698
 699 void inode_sub_bytes(struct inode *inode, loff_t bytes)
 700 {
 701         spin_lock(&inode->i_lock);
 702         __inode_sub_bytes(inode, bytes);
 703         spin_unlock(&inode->i_lock);
 704 }
 705
 706 EXPORT_SYMBOL(inode_sub_bytes);
 707
 708 loff_t inode_get_bytes(struct inode *inode)
 709 {
 710         loff_t ret;
 711
 712         spin_lock(&inode->i_lock);
 713         ret = (((loff_t)inode->i_blocks) << 9) + inode->i_bytes;
 714         spin_unlock(&inode->i_lock);
 715         return ret;
 716 }
 717
 718 EXPORT_SYMBOL(inode_get_bytes);
 719
 720 void inode_set_bytes(struct inode *inode, loff_t bytes)
 721 {
 722         /* Caller is here responsible for sufficient locking
 723          * (ie. inode->i_lock) */
 724         inode->i_blocks = bytes >> 9;
 725         inode->i_bytes = bytes & 511;
 726 }
 727
 728 EXPORT_SYMBOL(inode_set_bytes);