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
  19 #include <linux/uaccess.h>
  20 #include <asm/unistd.h>
  21
  22 /**
  23  * generic_fillattr - Fill in the basic attributes from the inode struct
  24  * @inode: Inode to use as the source
  25  * @stat: Where to fill in the attributes
  26  *
  27  * Fill in the basic attributes in the kstat structure from data that's to be
  28  * found on the VFS inode structure.  This is the default if no getattr inode
  29  * operation is supplied.
  30  */
  31 void generic_fillattr(struct inode *inode, struct kstat *stat)
  32 {
  33         stat->dev = inode->i_sb->s_dev;
  34         stat->ino = inode->i_ino;
  35         stat->mode = inode->i_mode;
  36         stat->nlink = inode->i_nlink;
  37         stat->uid = inode->i_uid;
  38         stat->gid = inode->i_gid;
  39         stat->rdev = inode->i_rdev;
  40         stat->size = i_size_read(inode);
  41         stat->atime = inode->i_atime;
  42         stat->mtime = inode->i_mtime;
  43         stat->ctime = inode->i_ctime;
  44         stat->blksize = i_blocksize(inode);
  45         stat->blocks = inode->i_blocks;
  46
  47         if (IS_NOATIME(inode))
  48                 stat->result_mask &= ~STATX_ATIME;
  49         if (IS_AUTOMOUNT(inode))
  50                 stat->attributes |= STATX_ATTR_AUTOMOUNT;
  51 }
  52 EXPORT_SYMBOL(generic_fillattr);
  53
  54 /**
  55  * vfs_getattr_nosec - getattr without security checks
  56  * @path: file to get attributes from
  57  * @stat: structure to return attributes in
  58  * @request_mask: STATX_xxx flags indicating what the caller wants
  59  * @query_flags: Query mode (KSTAT_QUERY_FLAGS)
  60  *
  61  * Get attributes without calling security_inode_getattr.
  62  *
  63  * Currently the only caller other than vfs_getattr is internal to the
  64  * filehandle lookup code, which uses only the inode number and returns no
  65  * attributes to any user.  Any other code probably wants vfs_getattr.
  66  */
  67 int vfs_getattr_nosec(const struct path *path, struct kstat *stat,
  68                       u32 request_mask, unsigned int query_flags)
  69 {
  70         struct inode *inode = d_backing_inode(path->dentry);
  71
  72         memset(stat, 0, sizeof(*stat));
  73         stat->result_mask |= STATX_BASIC_STATS;
  74         request_mask &= STATX_ALL;
  75         query_flags &= KSTAT_QUERY_FLAGS;
  76         if (inode->i_op->getattr)
  77                 return inode->i_op->getattr(path, stat, request_mask,
  78                                             query_flags);
  79
  80         generic_fillattr(inode, stat);
  81         return 0;
  82 }
  83 EXPORT_SYMBOL(vfs_getattr_nosec);
  84
  85 /*
  86  * vfs_getattr - Get the enhanced basic attributes of a file
  87  * @path: The file of interest
  88  * @stat: Where to return the statistics
  89  * @request_mask: STATX_xxx flags indicating what the caller wants
  90  * @query_flags: Query mode (KSTAT_QUERY_FLAGS)
  91  *
  92  * Ask the filesystem for a file's attributes.  The caller must indicate in
  93  * request_mask and query_flags to indicate what they want.
  94  *
  95  * If the file is remote, the filesystem can be forced to update the attributes
  96  * from the backing store by passing AT_STATX_FORCE_SYNC in query_flags or can
  97  * suppress the update by passing AT_STATX_DONT_SYNC.
  98  *
  99  * Bits must have been set in request_mask to indicate which attributes the
 100  * caller wants retrieving.  Any such attribute not requested may be returned
 101  * anyway, but the value may be approximate, and, if remote, may not have been
 102  * synchronised with the server.
 103  *
 104  * 0 will be returned on success, and a -ve error code if unsuccessful.
 105  */
 106 int vfs_getattr(const struct path *path, struct kstat *stat,
 107                 u32 request_mask, unsigned int query_flags)
 108 {
 109         int retval;
 110
 111         retval = security_inode_getattr(path);
 112         if (retval)
 113                 return retval;
 114         return vfs_getattr_nosec(path, stat, request_mask, query_flags);
 115 }
 116 EXPORT_SYMBOL(vfs_getattr);
 117
 118 /**
 119  * vfs_statx_fd - Get the enhanced basic attributes by file descriptor
 120  * @fd: The file descriptor referring to the file of interest
 121  * @stat: The result structure to fill in.
 122  * @request_mask: STATX_xxx flags indicating what the caller wants
 123  * @query_flags: Query mode (KSTAT_QUERY_FLAGS)
 124  *
 125  * This function is a wrapper around vfs_getattr().  The main difference is
 126  * that it uses a file descriptor to determine the file location.
 127  *
 128  * 0 will be returned on success, and a -ve error code if unsuccessful.
 129  */
 130 int vfs_statx_fd(unsigned int fd, struct kstat *stat,
 131                  u32 request_mask, unsigned int query_flags)
 132 {
 133         struct fd f = fdget_raw(fd);
 134         int error = -EBADF;
 135
 136         if (f.file) {
 137                 error = vfs_getattr(&f.file->f_path, stat,
 138                                     request_mask, query_flags);
 139                 fdput(f);
 140         }
 141         return error;
 142 }
 143 EXPORT_SYMBOL(vfs_statx_fd);
 144
 145 /**
 146  * vfs_statx - Get basic and extra attributes by filename
 147  * @dfd: A file descriptor representing the base dir for a relative filename
 148  * @filename: The name of the file of interest
 149  * @flags: Flags to control the query
 150  * @stat: The result structure to fill in.
 151  * @request_mask: STATX_xxx flags indicating what the caller wants
 152  *
 153  * This function is a wrapper around vfs_getattr().  The main difference is
 154  * that it uses a filename and base directory to determine the file location.
 155  * Additionally, the use of AT_SYMLINK_NOFOLLOW in flags will prevent a symlink
 156  * at the given name from being referenced.
 157  *
 158  * The caller must have preset stat->request_mask as for vfs_getattr().  The
 159  * flags are also used to load up stat->query_flags.
 160  *
 161  * 0 will be returned on success, and a -ve error code if unsuccessful.
 162  */
 163 int vfs_statx(int dfd, const char __user *filename, int flags,
 164               struct kstat *stat, u32 request_mask)
 165 {
 166         struct path path;
 167         int error = -EINVAL;
 168         unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_AUTOMOUNT;
 169
 170         if ((flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT |
 171                        AT_EMPTY_PATH | KSTAT_QUERY_FLAGS)) != 0)
 172                 return -EINVAL;
 173
 174         if (flags & AT_SYMLINK_NOFOLLOW)
 175                 lookup_flags &= ~LOOKUP_FOLLOW;
 176         if (flags & AT_NO_AUTOMOUNT)
 177                 lookup_flags &= ~LOOKUP_AUTOMOUNT;
 178         if (flags & AT_EMPTY_PATH)
 179                 lookup_flags |= LOOKUP_EMPTY;
 180
 181 retry:
 182         error = user_path_at(dfd, filename, lookup_flags, &path);
 183         if (error)
 184                 goto out;
 185
 186         error = vfs_getattr(&path, stat, request_mask, flags);
 187         path_put(&path);
 188         if (retry_estale(error, lookup_flags)) {
 189                 lookup_flags |= LOOKUP_REVAL;
 190                 goto retry;
 191         }
 192 out:
 193         return error;
 194 }
 195 EXPORT_SYMBOL(vfs_statx);
 196
 197
 198 #ifdef __ARCH_WANT_OLD_STAT
 199
 200 /*
 201  * For backward compatibility?  Maybe this should be moved
 202  * into arch/i386 instead?
 203  */
 204 static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf)
 205 {
 206         static int warncount = 5;
 207         struct __old_kernel_stat tmp;
 208
 209         if (warncount > 0) {
 210                 warncount--;
 211                 printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n",
 212                         current->comm);
 213         } else if (warncount < 0) {
 214                 /* it's laughable, but... */
 215                 warncount = 0;
 216         }
 217
 218         memset(&tmp, 0, sizeof(struct __old_kernel_stat));
 219         tmp.st_dev = old_encode_dev(stat->dev);
 220         tmp.st_ino = stat->ino;
 221         if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
 222                 return -EOVERFLOW;
 223         tmp.st_mode = stat->mode;
 224         tmp.st_nlink = stat->nlink;
 225         if (tmp.st_nlink != stat->nlink)
 226                 return -EOVERFLOW;
 227         SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
 228         SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
 229         tmp.st_rdev = old_encode_dev(stat->rdev);
 230 #if BITS_PER_LONG == 32
 231         if (stat->size > MAX_NON_LFS)
 232                 return -EOVERFLOW;
 233 #endif
 234         tmp.st_size = stat->size;
 235         tmp.st_atime = stat->atime.tv_sec;
 236         tmp.st_mtime = stat->mtime.tv_sec;
 237         tmp.st_ctime = stat->ctime.tv_sec;
 238         return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
 239 }
 240
 241 SYSCALL_DEFINE2(stat, const char __user *, filename,
 242                 struct __old_kernel_stat __user *, statbuf)
 243 {
 244         struct kstat stat;
 245         int error;
 246
 247         error = vfs_stat(filename, &stat);
 248         if (error)
 249                 return error;
 250
 251         return cp_old_stat(&stat, statbuf);
 252 }
 253
 254 SYSCALL_DEFINE2(lstat, const char __user *, filename,
 255                 struct __old_kernel_stat __user *, statbuf)
 256 {
 257         struct kstat stat;
 258         int error;
 259
 260         error = vfs_lstat(filename, &stat);
 261         if (error)
 262                 return error;
 263
 264         return cp_old_stat(&stat, statbuf);
 265 }
 266
 267 SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf)
 268 {
 269         struct kstat stat;
 270         int error = vfs_fstat(fd, &stat);
 271
 272         if (!error)
 273                 error = cp_old_stat(&stat, statbuf);
 274
 275         return error;
 276 }
 277
 278 #endif /* __ARCH_WANT_OLD_STAT */
 279
 280 #if BITS_PER_LONG == 32
 281 #  define choose_32_64(a,b) a
 282 #else
 283 #  define choose_32_64(a,b) b
 284 #endif
 285
 286 #define valid_dev(x)  choose_32_64(old_valid_dev(x),true)
 287 #define encode_dev(x) choose_32_64(old_encode_dev,new_encode_dev)(x)
 288
 289 #ifndef INIT_STRUCT_STAT_PADDING
 290 #  define INIT_STRUCT_STAT_PADDING(st) memset(&st, 0, sizeof(st))
 291 #endif
 292
 293 static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf)
 294 {
 295         struct stat tmp;
 296
 297         if (!valid_dev(stat->dev) || !valid_dev(stat->rdev))
 298                 return -EOVERFLOW;
 299 #if BITS_PER_LONG == 32
 300         if (stat->size > MAX_NON_LFS)
 301                 return -EOVERFLOW;
 302 #endif
 303
 304         INIT_STRUCT_STAT_PADDING(tmp);
 305         tmp.st_dev = encode_dev(stat->dev);
 306         tmp.st_ino = stat->ino;
 307         if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
 308                 return -EOVERFLOW;
 309         tmp.st_mode = stat->mode;
 310         tmp.st_nlink = stat->nlink;
 311         if (tmp.st_nlink != stat->nlink)
 312                 return -EOVERFLOW;
 313         SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
 314         SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
 315         tmp.st_rdev = encode_dev(stat->rdev);
 316         tmp.st_size = stat->size;
 317         tmp.st_atime = stat->atime.tv_sec;
 318         tmp.st_mtime = stat->mtime.tv_sec;
 319         tmp.st_ctime = stat->ctime.tv_sec;
 320 #ifdef STAT_HAVE_NSEC
 321         tmp.st_atime_nsec = stat->atime.tv_nsec;
 322         tmp.st_mtime_nsec = stat->mtime.tv_nsec;
 323         tmp.st_ctime_nsec = stat->ctime.tv_nsec;
 324 #endif
 325         tmp.st_blocks = stat->blocks;
 326         tmp.st_blksize = stat->blksize;
 327         return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
 328 }
 329
 330 SYSCALL_DEFINE2(newstat, const char __user *, filename,
 331                 struct stat __user *, statbuf)
 332 {
 333         struct kstat stat;
 334         int error = vfs_stat(filename, &stat);
 335
 336         if (error)
 337                 return error;
 338         return cp_new_stat(&stat, statbuf);
 339 }
 340
 341 SYSCALL_DEFINE2(newlstat, const char __user *, filename,
 342                 struct stat __user *, statbuf)
 343 {
 344         struct kstat stat;
 345         int error;
 346
 347         error = vfs_lstat(filename, &stat);
 348         if (error)
 349                 return error;
 350
 351         return cp_new_stat(&stat, statbuf);
 352 }
 353
 354 #if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT)
 355 SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename,
 356                 struct stat __user *, statbuf, int, flag)
 357 {
 358         struct kstat stat;
 359         int error;
 360
 361         error = vfs_fstatat(dfd, filename, &stat, flag);
 362         if (error)
 363                 return error;
 364         return cp_new_stat(&stat, statbuf);
 365 }
 366 #endif
 367
 368 SYSCALL_DEFINE2(newfstat, unsigned int, fd, struct stat __user *, statbuf)
 369 {
 370         struct kstat stat;
 371         int error = vfs_fstat(fd, &stat);
 372
 373         if (!error)
 374                 error = cp_new_stat(&stat, statbuf);
 375
 376         return error;
 377 }
 378
 379 SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname,
 380                 char __user *, buf, int, bufsiz)
 381 {
 382         struct path path;
 383         int error;
 384         int empty = 0;
 385         unsigned int lookup_flags = LOOKUP_EMPTY;
 386
 387         if (bufsiz <= 0)
 388                 return -EINVAL;
 389
 390 retry:
 391         error = user_path_at_empty(dfd, pathname, lookup_flags, &path, &empty);
 392         if (!error) {
 393                 struct inode *inode = d_backing_inode(path.dentry);
 394
 395                 error = empty ? -ENOENT : -EINVAL;
 396                 /*
 397                  * AFS mountpoints allow readlink(2) but are not symlinks
 398                  */
 399                 if (d_is_symlink(path.dentry) || inode->i_op->readlink) {
 400                         error = security_inode_readlink(path.dentry);
 401                         if (!error) {
 402                                 touch_atime(&path);
 403                                 error = vfs_readlink(path.dentry, buf, bufsiz);
 404                         }
 405                 }
 406                 path_put(&path);
 407                 if (retry_estale(error, lookup_flags)) {
 408                         lookup_flags |= LOOKUP_REVAL;
 409                         goto retry;
 410                 }
 411         }
 412         return error;
 413 }
 414
 415 SYSCALL_DEFINE3(readlink, const char __user *, path, char __user *, buf,
 416                 int, bufsiz)
 417 {
 418         return sys_readlinkat(AT_FDCWD, path, buf, bufsiz);
 419 }
 420
 421
 422 /* ---------- LFS-64 ----------- */
 423 #if defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_COMPAT_STAT64)
 424
 425 #ifndef INIT_STRUCT_STAT64_PADDING
 426 #  define INIT_STRUCT_STAT64_PADDING(st) memset(&st, 0, sizeof(st))
 427 #endif
 428
 429 static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf)
 430 {
 431         struct stat64 tmp;
 432
 433         INIT_STRUCT_STAT64_PADDING(tmp);
 434 #ifdef CONFIG_MIPS
 435         /* mips has weird padding, so we don't get 64 bits there */
 436         tmp.st_dev = new_encode_dev(stat->dev);
 437         tmp.st_rdev = new_encode_dev(stat->rdev);
 438 #else
 439         tmp.st_dev = huge_encode_dev(stat->dev);
 440         tmp.st_rdev = huge_encode_dev(stat->rdev);
 441 #endif
 442         tmp.st_ino = stat->ino;
 443         if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
 444                 return -EOVERFLOW;
 445 #ifdef STAT64_HAS_BROKEN_ST_INO
 446         tmp.__st_ino = stat->ino;
 447 #endif
 448         tmp.st_mode = stat->mode;
 449         tmp.st_nlink = stat->nlink;
 450         tmp.st_uid = from_kuid_munged(current_user_ns(), stat->uid);
 451         tmp.st_gid = from_kgid_munged(current_user_ns(), stat->gid);
 452         tmp.st_atime = stat->atime.tv_sec;
 453         tmp.st_atime_nsec = stat->atime.tv_nsec;
 454         tmp.st_mtime = stat->mtime.tv_sec;
 455         tmp.st_mtime_nsec = stat->mtime.tv_nsec;
 456         tmp.st_ctime = stat->ctime.tv_sec;
 457         tmp.st_ctime_nsec = stat->ctime.tv_nsec;
 458         tmp.st_size = stat->size;
 459         tmp.st_blocks = stat->blocks;
 460         tmp.st_blksize = stat->blksize;
 461         return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
 462 }
 463
 464 SYSCALL_DEFINE2(stat64, const char __user *, filename,
 465                 struct stat64 __user *, statbuf)
 466 {
 467         struct kstat stat;
 468         int error = vfs_stat(filename, &stat);
 469
 470         if (!error)
 471                 error = cp_new_stat64(&stat, statbuf);
 472
 473         return error;
 474 }
 475
 476 SYSCALL_DEFINE2(lstat64, const char __user *, filename,
 477                 struct stat64 __user *, statbuf)
 478 {
 479         struct kstat stat;
 480         int error = vfs_lstat(filename, &stat);
 481
 482         if (!error)
 483                 error = cp_new_stat64(&stat, statbuf);
 484
 485         return error;
 486 }
 487
 488 SYSCALL_DEFINE2(fstat64, unsigned long, fd, struct stat64 __user *, statbuf)
 489 {
 490         struct kstat stat;
 491         int error = vfs_fstat(fd, &stat);
 492
 493         if (!error)
 494                 error = cp_new_stat64(&stat, statbuf);
 495
 496         return error;
 497 }
 498
 499 SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename,
 500                 struct stat64 __user *, statbuf, int, flag)
 501 {
 502         struct kstat stat;
 503         int error;
 504
 505         error = vfs_fstatat(dfd, filename, &stat, flag);
 506         if (error)
 507                 return error;
 508         return cp_new_stat64(&stat, statbuf);
 509 }
 510 #endif /* __ARCH_WANT_STAT64 || __ARCH_WANT_COMPAT_STAT64 */
 511
 512 static inline int __put_timestamp(struct timespec *kts,
 513                                   struct statx_timestamp __user *uts)
 514 {
 515         return (__put_user(kts->tv_sec,         &uts->tv_sec            ) ||
 516                 __put_user(kts->tv_nsec,        &uts->tv_nsec           ) ||
 517                 __put_user(0,                   &uts->__reserved        ));
 518 }
 519
 520 /*
 521  * Set the statx results.
 522  */
 523 static long statx_set_result(struct kstat *stat, struct statx __user *buffer)
 524 {
 525         uid_t uid = from_kuid_munged(current_user_ns(), stat->uid);
 526         gid_t gid = from_kgid_munged(current_user_ns(), stat->gid);
 527
 528         if (__put_user(stat->result_mask,       &buffer->stx_mask       ) ||
 529             __put_user(stat->mode,              &buffer->stx_mode       ) ||
 530             __clear_user(&buffer->__spare0, sizeof(buffer->__spare0))     ||
 531             __put_user(stat->nlink,             &buffer->stx_nlink      ) ||
 532             __put_user(uid,                     &buffer->stx_uid        ) ||
 533             __put_user(gid,                     &buffer->stx_gid        ) ||
 534             __put_user(stat->attributes,        &buffer->stx_attributes ) ||
 535             __put_user(stat->blksize,           &buffer->stx_blksize    ) ||
 536             __put_user(MAJOR(stat->rdev),       &buffer->stx_rdev_major ) ||
 537             __put_user(MINOR(stat->rdev),       &buffer->stx_rdev_minor ) ||
 538             __put_user(MAJOR(stat->dev),        &buffer->stx_dev_major  ) ||
 539             __put_user(MINOR(stat->dev),        &buffer->stx_dev_minor  ) ||
 540             __put_timestamp(&stat->atime,       &buffer->stx_atime      ) ||
 541             __put_timestamp(&stat->btime,       &buffer->stx_btime      ) ||
 542             __put_timestamp(&stat->ctime,       &buffer->stx_ctime      ) ||
 543             __put_timestamp(&stat->mtime,       &buffer->stx_mtime      ) ||
 544             __put_user(stat->ino,               &buffer->stx_ino        ) ||
 545             __put_user(stat->size,              &buffer->stx_size       ) ||
 546             __put_user(stat->blocks,            &buffer->stx_blocks     ) ||
 547             __clear_user(&buffer->__spare1, sizeof(buffer->__spare1))     ||
 548             __clear_user(&buffer->__spare2, sizeof(buffer->__spare2)))
 549                 return -EFAULT;
 550
 551         return 0;
 552 }
 553
 554 /**
 555  * sys_statx - System call to get enhanced stats
 556  * @dfd: Base directory to pathwalk from *or* fd to stat.
 557  * @filename: File to stat *or* NULL.
 558  * @flags: AT_* flags to control pathwalk.
 559  * @mask: Parts of statx struct actually required.
 560  * @buffer: Result buffer.
 561  *
 562  * Note that if filename is NULL, then it does the equivalent of fstat() using
 563  * dfd to indicate the file of interest.
 564  */
 565 SYSCALL_DEFINE5(statx,
 566                 int, dfd, const char __user *, filename, unsigned, flags,
 567                 unsigned int, mask,
 568                 struct statx __user *, buffer)
 569 {
 570         struct kstat stat;
 571         int error;
 572
 573         if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_SYNC_TYPE)
 574                 return -EINVAL;
 575         if (!access_ok(VERIFY_WRITE, buffer, sizeof(*buffer)))
 576                 return -EFAULT;
 577
 578         if (filename)
 579                 error = vfs_statx(dfd, filename, flags, &stat, mask);
 580         else
 581                 error = vfs_statx_fd(dfd, &stat, mask, flags);
 582         if (error)
 583                 return error;
 584         return statx_set_result(&stat, buffer);
 585 }
 586
 587 /* Caller is here responsible for sufficient locking (ie. inode->i_lock) */
 588 void __inode_add_bytes(struct inode *inode, loff_t bytes)
 589 {
 590         inode->i_blocks += bytes >> 9;
 591         bytes &= 511;
 592         inode->i_bytes += bytes;
 593         if (inode->i_bytes >= 512) {
 594                 inode->i_blocks++;
 595                 inode->i_bytes -= 512;
 596         }
 597 }
 598
 599 void inode_add_bytes(struct inode *inode, loff_t bytes)
 600 {
 601         spin_lock(&inode->i_lock);
 602         __inode_add_bytes(inode, bytes);
 603         spin_unlock(&inode->i_lock);
 604 }
 605
 606 EXPORT_SYMBOL(inode_add_bytes);
 607
 608 void __inode_sub_bytes(struct inode *inode, loff_t bytes)
 609 {
 610         inode->i_blocks -= bytes >> 9;
 611         bytes &= 511;
 612         if (inode->i_bytes < bytes) {
 613                 inode->i_blocks--;
 614                 inode->i_bytes += 512;
 615         }
 616         inode->i_bytes -= bytes;
 617 }
 618
 619 EXPORT_SYMBOL(__inode_sub_bytes);
 620
 621 void inode_sub_bytes(struct inode *inode, loff_t bytes)
 622 {
 623         spin_lock(&inode->i_lock);
 624         __inode_sub_bytes(inode, bytes);
 625         spin_unlock(&inode->i_lock);
 626 }
 627
 628 EXPORT_SYMBOL(inode_sub_bytes);
 629
 630 loff_t inode_get_bytes(struct inode *inode)
 631 {
 632         loff_t ret;
 633
 634         spin_lock(&inode->i_lock);
 635         ret = (((loff_t)inode->i_blocks) << 9) + inode->i_bytes;
 636         spin_unlock(&inode->i_lock);
 637         return ret;
 638 }
 639
 640 EXPORT_SYMBOL(inode_get_bytes);
 641
 642 void inode_set_bytes(struct inode *inode, loff_t bytes)
 643 {
 644         /* Caller is here responsible for sufficient locking
 645          * (ie. inode->i_lock) */
 646         inode->i_blocks = bytes >> 9;
 647         inode->i_bytes = bytes & 511;
 648 }
 649
 650 EXPORT_SYMBOL(inode_set_bytes);