fs/stat.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  linux/fs/stat.c
   4  *
   5  *  Copyright (C) 1991, 1992  Linus Torvalds
   6  */
   7
   8 #include <linux/export.h>
   9 #include <linux/mm.h>
  10 #include <linux/errno.h>
  11 #include <linux/file.h>
  12 #include <linux/highuid.h>
  13 #include <linux/fs.h>
  14 #include <linux/namei.h>
  15 #include <linux/security.h>
  16 #include <linux/cred.h>
  17 #include <linux/syscalls.h>
  18 #include <linux/pagemap.h>
  19 #include <linux/compat.h>
  20
  21 #include <linux/uaccess.h>
  22 #include <asm/unistd.h>
  23
  24 /**
  25  * generic_fillattr - Fill in the basic attributes from the inode struct
  26  * @inode: Inode to use as the source
  27  * @stat: Where to fill in the attributes
  28  *
  29  * Fill in the basic attributes in the kstat structure from data that's to be
  30  * found on the VFS inode structure.  This is the default if no getattr inode
  31  * operation is supplied.
  32  */
  33 void generic_fillattr(struct inode *inode, struct kstat *stat)
  34 {
  35         stat->dev = inode->i_sb->s_dev;
  36         stat->ino = inode->i_ino;
  37         stat->mode = inode->i_mode;
  38         stat->nlink = inode->i_nlink;
  39         stat->uid = inode->i_uid;
  40         stat->gid = inode->i_gid;
  41         stat->rdev = inode->i_rdev;
  42         stat->size = i_size_read(inode);
  43         stat->atime = inode->i_atime;
  44         stat->mtime = inode->i_mtime;
  45         stat->ctime = inode->i_ctime;
  46         stat->blksize = i_blocksize(inode);
  47         stat->blocks = inode->i_blocks;
  48
  49         if (IS_NOATIME(inode))
  50                 stat->result_mask &= ~STATX_ATIME;
  51         if (IS_AUTOMOUNT(inode))
  52                 stat->attributes |= STATX_ATTR_AUTOMOUNT;
  53 }
  54 EXPORT_SYMBOL(generic_fillattr);
  55
  56 /**
  57  * vfs_getattr_nosec - getattr without security checks
  58  * @path: file to get attributes from
  59  * @stat: structure to return attributes in
  60  * @request_mask: STATX_xxx flags indicating what the caller wants
  61  * @query_flags: Query mode (KSTAT_QUERY_FLAGS)
  62  *
  63  * Get attributes without calling security_inode_getattr.
  64  *
  65  * Currently the only caller other than vfs_getattr is internal to the
  66  * filehandle lookup code, which uses only the inode number and returns no
  67  * attributes to any user.  Any other code probably wants vfs_getattr.
  68  */
  69 int vfs_getattr_nosec(const struct path *path, struct kstat *stat,
  70                       u32 request_mask, unsigned int query_flags)
  71 {
  72         struct inode *inode = d_backing_inode(path->dentry);
  73
  74         memset(stat, 0, sizeof(*stat));
  75         stat->result_mask |= STATX_BASIC_STATS;
  76         request_mask &= STATX_ALL;
  77         query_flags &= KSTAT_QUERY_FLAGS;
  78         if (inode->i_op->getattr)
  79                 return inode->i_op->getattr(path, stat, request_mask,
  80                                             query_flags);
  81
  82         generic_fillattr(inode, stat);
  83         return 0;
  84 }
  85 EXPORT_SYMBOL(vfs_getattr_nosec);
  86
  87 /*
  88  * vfs_getattr - Get the enhanced basic attributes of a file
  89  * @path: The file of interest
  90  * @stat: Where to return the statistics
  91  * @request_mask: STATX_xxx flags indicating what the caller wants
  92  * @query_flags: Query mode (KSTAT_QUERY_FLAGS)
  93  *
  94  * Ask the filesystem for a file's attributes.  The caller must indicate in
  95  * request_mask and query_flags to indicate what they want.
  96  *
  97  * If the file is remote, the filesystem can be forced to update the attributes
  98  * from the backing store by passing AT_STATX_FORCE_SYNC in query_flags or can
  99  * suppress the update by passing AT_STATX_DONT_SYNC.
 100  *
 101  * Bits must have been set in request_mask to indicate which attributes the
 102  * caller wants retrieving.  Any such attribute not requested may be returned
 103  * anyway, but the value may be approximate, and, if remote, may not have been
 104  * synchronised with the server.
 105  *
 106  * 0 will be returned on success, and a -ve error code if unsuccessful.
 107  */
 108 int vfs_getattr(const struct path *path, struct kstat *stat,
 109                 u32 request_mask, unsigned int query_flags)
 110 {
 111         int retval;
 112
 113         retval = security_inode_getattr(path);
 114         if (retval)
 115                 return retval;
 116         return vfs_getattr_nosec(path, stat, request_mask, query_flags);
 117 }
 118 EXPORT_SYMBOL(vfs_getattr);
 119
 120 /**
 121  * vfs_statx_fd - Get the enhanced basic attributes by file descriptor
 122  * @fd: The file descriptor referring to the file of interest
 123  * @stat: The result structure to fill in.
 124  * @request_mask: STATX_xxx flags indicating what the caller wants
 125  * @query_flags: Query mode (KSTAT_QUERY_FLAGS)
 126  *
 127  * This function is a wrapper around vfs_getattr().  The main difference is
 128  * that it uses a file descriptor to determine the file location.
 129  *
 130  * 0 will be returned on success, and a -ve error code if unsuccessful.
 131  */
 132 int vfs_statx_fd(unsigned int fd, struct kstat *stat,
 133                  u32 request_mask, unsigned int query_flags)
 134 {
 135         struct fd f;
 136         int error = -EBADF;
 137
 138         if (query_flags & ~KSTAT_QUERY_FLAGS)
 139                 return -EINVAL;
 140
 141         f = fdget_raw(fd);
 142         if (f.file) {
 143                 error = vfs_getattr(&f.file->f_path, stat,
 144                                     request_mask, query_flags);
 145                 fdput(f);
 146         }
 147         return error;
 148 }
 149 EXPORT_SYMBOL(vfs_statx_fd);
 150
 151 /**
 152  * vfs_statx - Get basic and extra attributes by filename
 153  * @dfd: A file descriptor representing the base dir for a relative filename
 154  * @filename: The name of the file of interest
 155  * @flags: Flags to control the query
 156  * @stat: The result structure to fill in.
 157  * @request_mask: STATX_xxx flags indicating what the caller wants
 158  *
 159  * This function is a wrapper around vfs_getattr().  The main difference is
 160  * that it uses a filename and base directory to determine the file location.
 161  * Additionally, the use of AT_SYMLINK_NOFOLLOW in flags will prevent a symlink
 162  * at the given name from being referenced.
 163  *
 164  * 0 will be returned on success, and a -ve error code if unsuccessful.
 165  */
 166 int vfs_statx(int dfd, const char __user *filename, int flags,
 167               struct kstat *stat, u32 request_mask)
 168 {
 169         struct path path;
 170         int error = -EINVAL;
 171         unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_AUTOMOUNT;
 172
 173         if ((flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT |
 174                        AT_EMPTY_PATH | KSTAT_QUERY_FLAGS)) != 0)
 175                 return -EINVAL;
 176
 177         if (flags & AT_SYMLINK_NOFOLLOW)
 178                 lookup_flags &= ~LOOKUP_FOLLOW;
 179         if (flags & AT_NO_AUTOMOUNT)
 180                 lookup_flags &= ~LOOKUP_AUTOMOUNT;
 181         if (flags & AT_EMPTY_PATH)
 182                 lookup_flags |= LOOKUP_EMPTY;
 183
 184 retry:
 185         error = user_path_at(dfd, filename, lookup_flags, &path);
 186         if (error)
 187                 goto out;
 188
 189         error = vfs_getattr(&path, stat, request_mask, flags);
 190         path_put(&path);
 191         if (retry_estale(error, lookup_flags)) {
 192                 lookup_flags |= LOOKUP_REVAL;
 193                 goto retry;
 194         }
 195 out:
 196         return error;
 197 }
 198 EXPORT_SYMBOL(vfs_statx);
 199
 200
 201 #ifdef __ARCH_WANT_OLD_STAT
 202
 203 /*
 204  * For backward compatibility?  Maybe this should be moved
 205  * into arch/i386 instead?
 206  */
 207 static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf)
 208 {
 209         static int warncount = 5;
 210         struct __old_kernel_stat tmp;
 211
 212         if (warncount > 0) {
 213                 warncount--;
 214                 printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n",
 215                         current->comm);
 216         } else if (warncount < 0) {
 217                 /* it's laughable, but... */
 218                 warncount = 0;
 219         }
 220
 221         memset(&tmp, 0, sizeof(struct __old_kernel_stat));
 222         tmp.st_dev = old_encode_dev(stat->dev);
 223         tmp.st_ino = stat->ino;
 224         if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
 225                 return -EOVERFLOW;
 226         tmp.st_mode = stat->mode;
 227         tmp.st_nlink = stat->nlink;
 228         if (tmp.st_nlink != stat->nlink)
 229                 return -EOVERFLOW;
 230         SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
 231         SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
 232         tmp.st_rdev = old_encode_dev(stat->rdev);
 233 #if BITS_PER_LONG == 32
 234         if (stat->size > MAX_NON_LFS)
 235                 return -EOVERFLOW;
 236 #endif
 237         tmp.st_size = stat->size;
 238         tmp.st_atime = stat->atime.tv_sec;
 239         tmp.st_mtime = stat->mtime.tv_sec;
 240         tmp.st_ctime = stat->ctime.tv_sec;
 241         return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
 242 }
 243
 244 SYSCALL_DEFINE2(stat, const char __user *, filename,
 245                 struct __old_kernel_stat __user *, statbuf)
 246 {
 247         struct kstat stat;
 248         int error;
 249
 250         error = vfs_stat(filename, &stat);
 251         if (error)
 252                 return error;
 253
 254         return cp_old_stat(&stat, statbuf);
 255 }
 256
 257 SYSCALL_DEFINE2(lstat, const char __user *, filename,
 258                 struct __old_kernel_stat __user *, statbuf)
 259 {
 260         struct kstat stat;
 261         int error;
 262
 263         error = vfs_lstat(filename, &stat);
 264         if (error)
 265                 return error;
 266
 267         return cp_old_stat(&stat, statbuf);
 268 }
 269
 270 SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf)
 271 {
 272         struct kstat stat;
 273         int error = vfs_fstat(fd, &stat);
 274
 275         if (!error)
 276                 error = cp_old_stat(&stat, statbuf);
 277
 278         return error;
 279 }
 280
 281 #endif /* __ARCH_WANT_OLD_STAT */
 282
 283 #if BITS_PER_LONG == 32
 284 #  define choose_32_64(a,b) a
 285 #else
 286 #  define choose_32_64(a,b) b
 287 #endif
 288
 289 #define valid_dev(x)  choose_32_64(old_valid_dev(x),true)
 290 #define encode_dev(x) choose_32_64(old_encode_dev,new_encode_dev)(x)
 291
 292 #ifndef INIT_STRUCT_STAT_PADDING
 293 #  define INIT_STRUCT_STAT_PADDING(st) memset(&st, 0, sizeof(st))
 294 #endif
 295
 296 static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf)
 297 {
 298         struct stat tmp;
 299
 300         if (!valid_dev(stat->dev) || !valid_dev(stat->rdev))
 301                 return -EOVERFLOW;
 302 #if BITS_PER_LONG == 32
 303         if (stat->size > MAX_NON_LFS)
 304                 return -EOVERFLOW;
 305 #endif
 306
 307         INIT_STRUCT_STAT_PADDING(tmp);
 308         tmp.st_dev = encode_dev(stat->dev);
 309         tmp.st_ino = stat->ino;
 310         if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
 311                 return -EOVERFLOW;
 312         tmp.st_mode = stat->mode;
 313         tmp.st_nlink = stat->nlink;
 314         if (tmp.st_nlink != stat->nlink)
 315                 return -EOVERFLOW;
 316         SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
 317         SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
 318         tmp.st_rdev = encode_dev(stat->rdev);
 319         tmp.st_size = stat->size;
 320         tmp.st_atime = stat->atime.tv_sec;
 321         tmp.st_mtime = stat->mtime.tv_sec;
 322         tmp.st_ctime = stat->ctime.tv_sec;
 323 #ifdef STAT_HAVE_NSEC
 324         tmp.st_atime_nsec = stat->atime.tv_nsec;
 325         tmp.st_mtime_nsec = stat->mtime.tv_nsec;
 326         tmp.st_ctime_nsec = stat->ctime.tv_nsec;
 327 #endif
 328         tmp.st_blocks = stat->blocks;
 329         tmp.st_blksize = stat->blksize;
 330         return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
 331 }
 332
 333 SYSCALL_DEFINE2(newstat, const char __user *, filename,
 334                 struct stat __user *, statbuf)
 335 {
 336         struct kstat stat;
 337         int error = vfs_stat(filename, &stat);
 338
 339         if (error)
 340                 return error;
 341         return cp_new_stat(&stat, statbuf);
 342 }
 343
 344 SYSCALL_DEFINE2(newlstat, const char __user *, filename,
 345                 struct stat __user *, statbuf)
 346 {
 347         struct kstat stat;
 348         int error;
 349
 350         error = vfs_lstat(filename, &stat);
 351         if (error)
 352                 return error;
 353
 354         return cp_new_stat(&stat, statbuf);
 355 }
 356
 357 #if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT)
 358 SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename,
 359                 struct stat __user *, statbuf, int, flag)
 360 {
 361         struct kstat stat;
 362         int error;
 363
 364         error = vfs_fstatat(dfd, filename, &stat, flag);
 365         if (error)
 366                 return error;
 367         return cp_new_stat(&stat, statbuf);
 368 }
 369 #endif
 370
 371 SYSCALL_DEFINE2(newfstat, unsigned int, fd, struct stat __user *, statbuf)
 372 {
 373         struct kstat stat;
 374         int error = vfs_fstat(fd, &stat);
 375
 376         if (!error)
 377                 error = cp_new_stat(&stat, statbuf);
 378
 379         return error;
 380 }
 381
 382 SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname,
 383                 char __user *, buf, int, bufsiz)
 384 {
 385         struct path path;
 386         int error;
 387         int empty = 0;
 388         unsigned int lookup_flags = LOOKUP_EMPTY;
 389
 390         if (bufsiz <= 0)
 391                 return -EINVAL;
 392
 393 retry:
 394         error = user_path_at_empty(dfd, pathname, lookup_flags, &path, &empty);
 395         if (!error) {
 396                 struct inode *inode = d_backing_inode(path.dentry);
 397
 398                 error = empty ? -ENOENT : -EINVAL;
 399                 /*
 400                  * AFS mountpoints allow readlink(2) but are not symlinks
 401                  */
 402                 if (d_is_symlink(path.dentry) || inode->i_op->readlink) {
 403                         error = security_inode_readlink(path.dentry);
 404                         if (!error) {
 405                                 touch_atime(&path);
 406                                 error = vfs_readlink(path.dentry, buf, bufsiz);
 407                         }
 408                 }
 409                 path_put(&path);
 410                 if (retry_estale(error, lookup_flags)) {
 411                         lookup_flags |= LOOKUP_REVAL;
 412                         goto retry;
 413                 }
 414         }
 415         return error;
 416 }
 417
 418 SYSCALL_DEFINE3(readlink, const char __user *, path, char __user *, buf,
 419                 int, bufsiz)
 420 {
 421         return sys_readlinkat(AT_FDCWD, path, buf, bufsiz);
 422 }
 423
 424
 425 /* ---------- LFS-64 ----------- */
 426 #if defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_COMPAT_STAT64)
 427
 428 #ifndef INIT_STRUCT_STAT64_PADDING
 429 #  define INIT_STRUCT_STAT64_PADDING(st) memset(&st, 0, sizeof(st))
 430 #endif
 431
 432 static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf)
 433 {
 434         struct stat64 tmp;
 435
 436         INIT_STRUCT_STAT64_PADDING(tmp);
 437 #ifdef CONFIG_MIPS
 438         /* mips has weird padding, so we don't get 64 bits there */
 439         tmp.st_dev = new_encode_dev(stat->dev);
 440         tmp.st_rdev = new_encode_dev(stat->rdev);
 441 #else
 442         tmp.st_dev = huge_encode_dev(stat->dev);
 443         tmp.st_rdev = huge_encode_dev(stat->rdev);
 444 #endif
 445         tmp.st_ino = stat->ino;
 446         if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
 447                 return -EOVERFLOW;
 448 #ifdef STAT64_HAS_BROKEN_ST_INO
 449         tmp.__st_ino = stat->ino;
 450 #endif
 451         tmp.st_mode = stat->mode;
 452         tmp.st_nlink = stat->nlink;
 453         tmp.st_uid = from_kuid_munged(current_user_ns(), stat->uid);
 454         tmp.st_gid = from_kgid_munged(current_user_ns(), stat->gid);
 455         tmp.st_atime = stat->atime.tv_sec;
 456         tmp.st_atime_nsec = stat->atime.tv_nsec;
 457         tmp.st_mtime = stat->mtime.tv_sec;
 458         tmp.st_mtime_nsec = stat->mtime.tv_nsec;
 459         tmp.st_ctime = stat->ctime.tv_sec;
 460         tmp.st_ctime_nsec = stat->ctime.tv_nsec;
 461         tmp.st_size = stat->size;
 462         tmp.st_blocks = stat->blocks;
 463         tmp.st_blksize = stat->blksize;
 464         return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
 465 }
 466
 467 SYSCALL_DEFINE2(stat64, const char __user *, filename,
 468                 struct stat64 __user *, statbuf)
 469 {
 470         struct kstat stat;
 471         int error = vfs_stat(filename, &stat);
 472
 473         if (!error)
 474                 error = cp_new_stat64(&stat, statbuf);
 475
 476         return error;
 477 }
 478
 479 SYSCALL_DEFINE2(lstat64, const char __user *, filename,
 480                 struct stat64 __user *, statbuf)
 481 {
 482         struct kstat stat;
 483         int error = vfs_lstat(filename, &stat);
 484
 485         if (!error)
 486                 error = cp_new_stat64(&stat, statbuf);
 487
 488         return error;
 489 }
 490
 491 SYSCALL_DEFINE2(fstat64, unsigned long, fd, struct stat64 __user *, statbuf)
 492 {
 493         struct kstat stat;
 494         int error = vfs_fstat(fd, &stat);
 495
 496         if (!error)
 497                 error = cp_new_stat64(&stat, statbuf);
 498
 499         return error;
 500 }
 501
 502 SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename,
 503                 struct stat64 __user *, statbuf, int, flag)
 504 {
 505         struct kstat stat;
 506         int error;
 507
 508         error = vfs_fstatat(dfd, filename, &stat, flag);
 509         if (error)
 510                 return error;
 511         return cp_new_stat64(&stat, statbuf);
 512 }
 513 #endif /* __ARCH_WANT_STAT64 || __ARCH_WANT_COMPAT_STAT64 */
 514
 515 static noinline_for_stack int
 516 cp_statx(const struct kstat *stat, struct statx __user *buffer)
 517 {
 518         struct statx tmp;
 519
 520         memset(&tmp, 0, sizeof(tmp));
 521
 522         tmp.stx_mask = stat->result_mask;
 523         tmp.stx_blksize = stat->blksize;
 524         tmp.stx_attributes = stat->attributes;
 525         tmp.stx_nlink = stat->nlink;
 526         tmp.stx_uid = from_kuid_munged(current_user_ns(), stat->uid);
 527         tmp.stx_gid = from_kgid_munged(current_user_ns(), stat->gid);
 528         tmp.stx_mode = stat->mode;
 529         tmp.stx_ino = stat->ino;
 530         tmp.stx_size = stat->size;
 531         tmp.stx_blocks = stat->blocks;
 532         tmp.stx_attributes_mask = stat->attributes_mask;
 533         tmp.stx_atime.tv_sec = stat->atime.tv_sec;
 534         tmp.stx_atime.tv_nsec = stat->atime.tv_nsec;
 535         tmp.stx_btime.tv_sec = stat->btime.tv_sec;
 536         tmp.stx_btime.tv_nsec = stat->btime.tv_nsec;
 537         tmp.stx_ctime.tv_sec = stat->ctime.tv_sec;
 538         tmp.stx_ctime.tv_nsec = stat->ctime.tv_nsec;
 539         tmp.stx_mtime.tv_sec = stat->mtime.tv_sec;
 540         tmp.stx_mtime.tv_nsec = stat->mtime.tv_nsec;
 541         tmp.stx_rdev_major = MAJOR(stat->rdev);
 542         tmp.stx_rdev_minor = MINOR(stat->rdev);
 543         tmp.stx_dev_major = MAJOR(stat->dev);
 544         tmp.stx_dev_minor = MINOR(stat->dev);
 545
 546         return copy_to_user(buffer, &tmp, sizeof(tmp)) ? -EFAULT : 0;
 547 }
 548
 549 /**
 550  * sys_statx - System call to get enhanced stats
 551  * @dfd: Base directory to pathwalk from *or* fd to stat.
 552  * @filename: File to stat or "" with AT_EMPTY_PATH
 553  * @flags: AT_* flags to control pathwalk.
 554  * @mask: Parts of statx struct actually required.
 555  * @buffer: Result buffer.
 556  *
 557  * Note that fstat() can be emulated by setting dfd to the fd of interest,
 558  * supplying "" as the filename and setting AT_EMPTY_PATH in the flags.
 559  */
 560 SYSCALL_DEFINE5(statx,
 561                 int, dfd, const char __user *, filename, unsigned, flags,
 562                 unsigned int, mask,
 563                 struct statx __user *, buffer)
 564 {
 565         struct kstat stat;
 566         int error;
 567
 568         if (mask & STATX__RESERVED)
 569                 return -EINVAL;
 570         if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_SYNC_TYPE)
 571                 return -EINVAL;
 572
 573         error = vfs_statx(dfd, filename, flags, &stat, mask);
 574         if (error)
 575                 return error;
 576
 577         return cp_statx(&stat, buffer);
 578 }
 579
 580 #ifdef CONFIG_COMPAT
 581 static int cp_compat_stat(struct kstat *stat, struct compat_stat __user *ubuf)
 582 {
 583         struct compat_stat tmp;
 584
 585         if (!old_valid_dev(stat->dev) || !old_valid_dev(stat->rdev))
 586                 return -EOVERFLOW;
 587
 588         memset(&tmp, 0, sizeof(tmp));
 589         tmp.st_dev = old_encode_dev(stat->dev);
 590         tmp.st_ino = stat->ino;
 591         if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
 592                 return -EOVERFLOW;
 593         tmp.st_mode = stat->mode;
 594         tmp.st_nlink = stat->nlink;
 595         if (tmp.st_nlink != stat->nlink)
 596                 return -EOVERFLOW;
 597         SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
 598         SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
 599         tmp.st_rdev = old_encode_dev(stat->rdev);
 600         if ((u64) stat->size > MAX_NON_LFS)
 601                 return -EOVERFLOW;
 602         tmp.st_size = stat->size;
 603         tmp.st_atime = stat->atime.tv_sec;
 604         tmp.st_atime_nsec = stat->atime.tv_nsec;
 605         tmp.st_mtime = stat->mtime.tv_sec;
 606         tmp.st_mtime_nsec = stat->mtime.tv_nsec;
 607         tmp.st_ctime = stat->ctime.tv_sec;
 608         tmp.st_ctime_nsec = stat->ctime.tv_nsec;
 609         tmp.st_blocks = stat->blocks;
 610         tmp.st_blksize = stat->blksize;
 611         return copy_to_user(ubuf, &tmp, sizeof(tmp)) ? -EFAULT : 0;
 612 }
 613
 614 COMPAT_SYSCALL_DEFINE2(newstat, const char __user *, filename,
 615                        struct compat_stat __user *, statbuf)
 616 {
 617         struct kstat stat;
 618         int error;
 619
 620         error = vfs_stat(filename, &stat);
 621         if (error)
 622                 return error;
 623         return cp_compat_stat(&stat, statbuf);
 624 }
 625
 626 COMPAT_SYSCALL_DEFINE2(newlstat, const char __user *, filename,
 627                        struct compat_stat __user *, statbuf)
 628 {
 629         struct kstat stat;
 630         int error;
 631
 632         error = vfs_lstat(filename, &stat);
 633         if (error)
 634                 return error;
 635         return cp_compat_stat(&stat, statbuf);
 636 }
 637
 638 #ifndef __ARCH_WANT_STAT64
 639 COMPAT_SYSCALL_DEFINE4(newfstatat, unsigned int, dfd,
 640                        const char __user *, filename,
 641                        struct compat_stat __user *, statbuf, int, flag)
 642 {
 643         struct kstat stat;
 644         int error;
 645
 646         error = vfs_fstatat(dfd, filename, &stat, flag);
 647         if (error)
 648                 return error;
 649         return cp_compat_stat(&stat, statbuf);
 650 }
 651 #endif
 652
 653 COMPAT_SYSCALL_DEFINE2(newfstat, unsigned int, fd,
 654                        struct compat_stat __user *, statbuf)
 655 {
 656         struct kstat stat;
 657         int error = vfs_fstat(fd, &stat);
 658
 659         if (!error)
 660                 error = cp_compat_stat(&stat, statbuf);
 661         return error;
 662 }
 663 #endif
 664
 665 /* Caller is here responsible for sufficient locking (ie. inode->i_lock) */
 666 void __inode_add_bytes(struct inode *inode, loff_t bytes)
 667 {
 668         inode->i_blocks += bytes >> 9;
 669         bytes &= 511;
 670         inode->i_bytes += bytes;
 671         if (inode->i_bytes >= 512) {
 672                 inode->i_blocks++;
 673                 inode->i_bytes -= 512;
 674         }
 675 }
 676 EXPORT_SYMBOL(__inode_add_bytes);
 677
 678 void inode_add_bytes(struct inode *inode, loff_t bytes)
 679 {
 680         spin_lock(&inode->i_lock);
 681         __inode_add_bytes(inode, bytes);
 682         spin_unlock(&inode->i_lock);
 683 }
 684
 685 EXPORT_SYMBOL(inode_add_bytes);
 686
 687 void __inode_sub_bytes(struct inode *inode, loff_t bytes)
 688 {
 689         inode->i_blocks -= bytes >> 9;
 690         bytes &= 511;
 691         if (inode->i_bytes < bytes) {
 692                 inode->i_blocks--;
 693                 inode->i_bytes += 512;
 694         }
 695         inode->i_bytes -= bytes;
 696 }
 697
 698 EXPORT_SYMBOL(__inode_sub_bytes);
 699
 700 void inode_sub_bytes(struct inode *inode, loff_t bytes)
 701 {
 702         spin_lock(&inode->i_lock);
 703         __inode_sub_bytes(inode, bytes);
 704         spin_unlock(&inode->i_lock);
 705 }
 706
 707 EXPORT_SYMBOL(inode_sub_bytes);
 708
 709 loff_t inode_get_bytes(struct inode *inode)
 710 {
 711         loff_t ret;
 712
 713         spin_lock(&inode->i_lock);
 714         ret = __inode_get_bytes(inode);
 715         spin_unlock(&inode->i_lock);
 716         return ret;
 717 }
 718
 719 EXPORT_SYMBOL(inode_get_bytes);
 720
 721 void inode_set_bytes(struct inode *inode, loff_t bytes)
 722 {
 723         /* Caller is here responsible for sufficient locking
 724          * (ie. inode->i_lock) */
 725         inode->i_blocks = bytes >> 9;
 726         inode->i_bytes = bytes & 511;
 727 }
 728
 729 EXPORT_SYMBOL(inode_set_bytes);