fs/ioctl.c

   1 /*
   2  *  linux/fs/ioctl.c
   3  *
   4  *  Copyright (C) 1991, 1992  Linus Torvalds
   5  */
   6
   7 #include <linux/syscalls.h>
   8 #include <linux/mm.h>
   9 #include <linux/capability.h>
  10 #include <linux/file.h>
  11 #include <linux/fs.h>
  12 #include <linux/security.h>
  13 #include <linux/export.h>
  14 #include <linux/uaccess.h>
  15 #include <linux/writeback.h>
  16 #include <linux/buffer_head.h>
  17 #include <linux/falloc.h>
  18 #include "internal.h"
  19
  20 #include <asm/ioctls.h>
  21
  22 /* So that the fiemap access checks can't overflow on 32 bit machines. */
  23 #define FIEMAP_MAX_EXTENTS      (UINT_MAX / sizeof(struct fiemap_extent))
  24
  25 /**
  26  * vfs_ioctl - call filesystem specific ioctl methods
  27  * @filp:       open file to invoke ioctl method on
  28  * @cmd:        ioctl command to execute
  29  * @arg:        command-specific argument for ioctl
  30  *
  31  * Invokes filesystem specific ->unlocked_ioctl, if one exists; otherwise
  32  * returns -ENOTTY.
  33  *
  34  * Returns 0 on success, -errno on error.
  35  */
  36 long vfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
  37 {
  38         int error = -ENOTTY;
  39
  40         if (!filp->f_op->unlocked_ioctl)
  41                 goto out;
  42
  43         error = filp->f_op->unlocked_ioctl(filp, cmd, arg);
  44         if (error == -ENOIOCTLCMD)
  45                 error = -ENOTTY;
  46  out:
  47         return error;
  48 }
  49
  50 static int ioctl_fibmap(struct file *filp, int __user *p)
  51 {
  52         struct address_space *mapping = filp->f_mapping;
  53         int res, block;
  54
  55         /* do we support this mess? */
  56         if (!mapping->a_ops->bmap)
  57                 return -EINVAL;
  58         if (!capable(CAP_SYS_RAWIO))
  59                 return -EPERM;
  60         res = get_user(block, p);
  61         if (res)
  62                 return res;
  63         res = mapping->a_ops->bmap(mapping, block);
  64         return put_user(res, p);
  65 }
  66
  67 /**
  68  * fiemap_fill_next_extent - Fiemap helper function
  69  * @fieinfo:    Fiemap context passed into ->fiemap
  70  * @logical:    Extent logical start offset, in bytes
  71  * @phys:       Extent physical start offset, in bytes
  72  * @len:        Extent length, in bytes
  73  * @flags:      FIEMAP_EXTENT flags that describe this extent
  74  *
  75  * Called from file system ->fiemap callback. Will populate extent
  76  * info as passed in via arguments and copy to user memory. On
  77  * success, extent count on fieinfo is incremented.
  78  *
  79  * Returns 0 on success, -errno on error, 1 if this was the last
  80  * extent that will fit in user array.
  81  */
  82 #define SET_UNKNOWN_FLAGS       (FIEMAP_EXTENT_DELALLOC)
  83 #define SET_NO_UNMOUNTED_IO_FLAGS       (FIEMAP_EXTENT_DATA_ENCRYPTED)
  84 #define SET_NOT_ALIGNED_FLAGS   (FIEMAP_EXTENT_DATA_TAIL|FIEMAP_EXTENT_DATA_INLINE)
  85 int fiemap_fill_next_extent(struct fiemap_extent_info *fieinfo, u64 logical,
  86                             u64 phys, u64 len, u32 flags)
  87 {
  88         struct fiemap_extent extent;
  89         struct fiemap_extent __user *dest = fieinfo->fi_extents_start;
  90
  91         /* only count the extents */
  92         if (fieinfo->fi_extents_max == 0) {
  93                 fieinfo->fi_extents_mapped++;
  94                 return (flags & FIEMAP_EXTENT_LAST) ? 1 : 0;
  95         }
  96
  97         if (fieinfo->fi_extents_mapped >= fieinfo->fi_extents_max)
  98                 return 1;
  99
 100         if (flags & SET_UNKNOWN_FLAGS)
 101                 flags |= FIEMAP_EXTENT_UNKNOWN;
 102         if (flags & SET_NO_UNMOUNTED_IO_FLAGS)
 103                 flags |= FIEMAP_EXTENT_ENCODED;
 104         if (flags & SET_NOT_ALIGNED_FLAGS)
 105                 flags |= FIEMAP_EXTENT_NOT_ALIGNED;
 106
 107         memset(&extent, 0, sizeof(extent));
 108         extent.fe_logical = logical;
 109         extent.fe_physical = phys;
 110         extent.fe_length = len;
 111         extent.fe_flags = flags;
 112
 113         dest += fieinfo->fi_extents_mapped;
 114         if (copy_to_user(dest, &extent, sizeof(extent)))
 115                 return -EFAULT;
 116
 117         fieinfo->fi_extents_mapped++;
 118         if (fieinfo->fi_extents_mapped == fieinfo->fi_extents_max)
 119                 return 1;
 120         return (flags & FIEMAP_EXTENT_LAST) ? 1 : 0;
 121 }
 122 EXPORT_SYMBOL(fiemap_fill_next_extent);
 123
 124 /**
 125  * fiemap_check_flags - check validity of requested flags for fiemap
 126  * @fieinfo:    Fiemap context passed into ->fiemap
 127  * @fs_flags:   Set of fiemap flags that the file system understands
 128  *
 129  * Called from file system ->fiemap callback. This will compute the
 130  * intersection of valid fiemap flags and those that the fs supports. That
 131  * value is then compared against the user supplied flags. In case of bad user
 132  * flags, the invalid values will be written into the fieinfo structure, and
 133  * -EBADR is returned, which tells ioctl_fiemap() to return those values to
 134  * userspace. For this reason, a return code of -EBADR should be preserved.
 135  *
 136  * Returns 0 on success, -EBADR on bad flags.
 137  */
 138 int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags)
 139 {
 140         u32 incompat_flags;
 141
 142         incompat_flags = fieinfo->fi_flags & ~(FIEMAP_FLAGS_COMPAT & fs_flags);
 143         if (incompat_flags) {
 144                 fieinfo->fi_flags = incompat_flags;
 145                 return -EBADR;
 146         }
 147         return 0;
 148 }
 149 EXPORT_SYMBOL(fiemap_check_flags);
 150
 151 static int fiemap_check_ranges(struct super_block *sb,
 152                                u64 start, u64 len, u64 *new_len)
 153 {
 154         u64 maxbytes = (u64) sb->s_maxbytes;
 155
 156         *new_len = len;
 157
 158         if (len == 0)
 159                 return -EINVAL;
 160
 161         if (start > maxbytes)
 162                 return -EFBIG;
 163
 164         /*
 165          * Shrink request scope to what the fs can actually handle.
 166          */
 167         if (len > maxbytes || (maxbytes - len) < start)
 168                 *new_len = maxbytes - start;
 169
 170         return 0;
 171 }
 172
 173 static int ioctl_fiemap(struct file *filp, unsigned long arg)
 174 {
 175         struct fiemap fiemap;
 176         struct fiemap __user *ufiemap = (struct fiemap __user *) arg;
 177         struct fiemap_extent_info fieinfo = { 0, };
 178         struct inode *inode = file_inode(filp);
 179         struct super_block *sb = inode->i_sb;
 180         u64 len;
 181         int error;
 182
 183         if (!inode->i_op->fiemap)
 184                 return -EOPNOTSUPP;
 185
 186         if (copy_from_user(&fiemap, ufiemap, sizeof(fiemap)))
 187                 return -EFAULT;
 188
 189         if (fiemap.fm_extent_count > FIEMAP_MAX_EXTENTS)
 190                 return -EINVAL;
 191
 192         error = fiemap_check_ranges(sb, fiemap.fm_start, fiemap.fm_length,
 193                                     &len);
 194         if (error)
 195                 return error;
 196
 197         fieinfo.fi_flags = fiemap.fm_flags;
 198         fieinfo.fi_extents_max = fiemap.fm_extent_count;
 199         fieinfo.fi_extents_start = ufiemap->fm_extents;
 200
 201         if (fiemap.fm_extent_count != 0 &&
 202             !access_ok(VERIFY_WRITE, fieinfo.fi_extents_start,
 203                        fieinfo.fi_extents_max * sizeof(struct fiemap_extent)))
 204                 return -EFAULT;
 205
 206         if (fieinfo.fi_flags & FIEMAP_FLAG_SYNC)
 207                 filemap_write_and_wait(inode->i_mapping);
 208
 209         error = inode->i_op->fiemap(inode, &fieinfo, fiemap.fm_start, len);
 210         fiemap.fm_flags = fieinfo.fi_flags;
 211         fiemap.fm_mapped_extents = fieinfo.fi_extents_mapped;
 212         if (copy_to_user(ufiemap, &fiemap, sizeof(fiemap)))
 213                 error = -EFAULT;
 214
 215         return error;
 216 }
 217
 218 static long ioctl_file_clone(struct file *dst_file, unsigned long srcfd,
 219                              u64 off, u64 olen, u64 destoff)
 220 {
 221         struct fd src_file = fdget(srcfd);
 222         int ret;
 223
 224         if (!src_file.file)
 225                 return -EBADF;
 226         ret = vfs_clone_file_range(src_file.file, off, dst_file, destoff, olen);
 227         fdput(src_file);
 228         return ret;
 229 }
 230
 231 static long ioctl_file_clone_range(struct file *file, void __user *argp)
 232 {
 233         struct file_clone_range args;
 234
 235         if (copy_from_user(&args, argp, sizeof(args)))
 236                 return -EFAULT;
 237         return ioctl_file_clone(file, args.src_fd, args.src_offset,
 238                                 args.src_length, args.dest_offset);
 239 }
 240
 241 #ifdef CONFIG_BLOCK
 242
 243 static inline sector_t logical_to_blk(struct inode *inode, loff_t offset)
 244 {
 245         return (offset >> inode->i_blkbits);
 246 }
 247
 248 static inline loff_t blk_to_logical(struct inode *inode, sector_t blk)
 249 {
 250         return (blk << inode->i_blkbits);
 251 }
 252
 253 /**
 254  * __generic_block_fiemap - FIEMAP for block based inodes (no locking)
 255  * @inode: the inode to map
 256  * @fieinfo: the fiemap info struct that will be passed back to userspace
 257  * @start: where to start mapping in the inode
 258  * @len: how much space to map
 259  * @get_block: the fs's get_block function
 260  *
 261  * This does FIEMAP for block based inodes.  Basically it will just loop
 262  * through get_block until we hit the number of extents we want to map, or we
 263  * go past the end of the file and hit a hole.
 264  *
 265  * If it is possible to have data blocks beyond a hole past @inode->i_size, then
 266  * please do not use this function, it will stop at the first unmapped block
 267  * beyond i_size.
 268  *
 269  * If you use this function directly, you need to do your own locking. Use
 270  * generic_block_fiemap if you want the locking done for you.
 271  */
 272
 273 int __generic_block_fiemap(struct inode *inode,
 274                            struct fiemap_extent_info *fieinfo, loff_t start,
 275                            loff_t len, get_block_t *get_block)
 276 {
 277         struct buffer_head map_bh;
 278         sector_t start_blk, last_blk;
 279         loff_t isize = i_size_read(inode);
 280         u64 logical = 0, phys = 0, size = 0;
 281         u32 flags = FIEMAP_EXTENT_MERGED;
 282         bool past_eof = false, whole_file = false;
 283         int ret = 0;
 284
 285         ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC);
 286         if (ret)
 287                 return ret;
 288
 289         /*
 290          * Either the i_mutex or other appropriate locking needs to be held
 291          * since we expect isize to not change at all through the duration of
 292          * this call.
 293          */
 294         if (len >= isize) {
 295                 whole_file = true;
 296                 len = isize;
 297         }
 298
 299         /*
 300          * Some filesystems can't deal with being asked to map less than
 301          * blocksize, so make sure our len is at least block length.
 302          */
 303         if (logical_to_blk(inode, len) == 0)
 304                 len = blk_to_logical(inode, 1);
 305
 306         start_blk = logical_to_blk(inode, start);
 307         last_blk = logical_to_blk(inode, start + len - 1);
 308
 309         do {
 310                 /*
 311                  * we set b_size to the total size we want so it will map as
 312                  * many contiguous blocks as possible at once
 313                  */
 314                 memset(&map_bh, 0, sizeof(struct buffer_head));
 315                 map_bh.b_size = len;
 316
 317                 ret = get_block(inode, start_blk, &map_bh, 0);
 318                 if (ret)
 319                         break;
 320
 321                 /* HOLE */
 322                 if (!buffer_mapped(&map_bh)) {
 323                         start_blk++;
 324
 325                         /*
 326                          * We want to handle the case where there is an
 327                          * allocated block at the front of the file, and then
 328                          * nothing but holes up to the end of the file properly,
 329                          * to make sure that extent at the front gets properly
 330                          * marked with FIEMAP_EXTENT_LAST
 331                          */
 332                         if (!past_eof &&
 333                             blk_to_logical(inode, start_blk) >= isize)
 334                                 past_eof = 1;
 335
 336                         /*
 337                          * First hole after going past the EOF, this is our
 338                          * last extent
 339                          */
 340                         if (past_eof && size) {
 341                                 flags = FIEMAP_EXTENT_MERGED|FIEMAP_EXTENT_LAST;
 342                                 ret = fiemap_fill_next_extent(fieinfo, logical,
 343                                                               phys, size,
 344                                                               flags);
 345                         } else if (size) {
 346                                 ret = fiemap_fill_next_extent(fieinfo, logical,
 347                                                               phys, size, flags);
 348                                 size = 0;
 349                         }
 350
 351                         /* if we have holes up to/past EOF then we're done */
 352                         if (start_blk > last_blk || past_eof || ret)
 353                                 break;
 354                 } else {
 355                         /*
 356                          * We have gone over the length of what we wanted to
 357                          * map, and it wasn't the entire file, so add the extent
 358                          * we got last time and exit.
 359                          *
 360                          * This is for the case where say we want to map all the
 361                          * way up to the second to the last block in a file, but
 362                          * the last block is a hole, making the second to last
 363                          * block FIEMAP_EXTENT_LAST.  In this case we want to
 364                          * see if there is a hole after the second to last block
 365                          * so we can mark it properly.  If we found data after
 366                          * we exceeded the length we were requesting, then we
 367                          * are good to go, just add the extent to the fieinfo
 368                          * and break
 369                          */
 370                         if (start_blk > last_blk && !whole_file) {
 371                                 ret = fiemap_fill_next_extent(fieinfo, logical,
 372                                                               phys, size,
 373                                                               flags);
 374                                 break;
 375                         }
 376
 377                         /*
 378                          * if size != 0 then we know we already have an extent
 379                          * to add, so add it.
 380                          */
 381                         if (size) {
 382                                 ret = fiemap_fill_next_extent(fieinfo, logical,
 383                                                               phys, size,
 384                                                               flags);
 385                                 if (ret)
 386                                         break;
 387                         }
 388
 389                         logical = blk_to_logical(inode, start_blk);
 390                         phys = blk_to_logical(inode, map_bh.b_blocknr);
 391                         size = map_bh.b_size;
 392                         flags = FIEMAP_EXTENT_MERGED;
 393
 394                         start_blk += logical_to_blk(inode, size);
 395
 396                         /*
 397                          * If we are past the EOF, then we need to make sure as
 398                          * soon as we find a hole that the last extent we found
 399                          * is marked with FIEMAP_EXTENT_LAST
 400                          */
 401                         if (!past_eof && logical + size >= isize)
 402                                 past_eof = true;
 403                 }
 404                 cond_resched();
 405                 if (fatal_signal_pending(current)) {
 406                         ret = -EINTR;
 407                         break;
 408                 }
 409
 410         } while (1);
 411
 412         /* If ret is 1 then we just hit the end of the extent array */
 413         if (ret == 1)
 414                 ret = 0;
 415
 416         return ret;
 417 }
 418 EXPORT_SYMBOL(__generic_block_fiemap);
 419
 420 /**
 421  * generic_block_fiemap - FIEMAP for block based inodes
 422  * @inode: The inode to map
 423  * @fieinfo: The mapping information
 424  * @start: The initial block to map
 425  * @len: The length of the extect to attempt to map
 426  * @get_block: The block mapping function for the fs
 427  *
 428  * Calls __generic_block_fiemap to map the inode, after taking
 429  * the inode's mutex lock.
 430  */
 431
 432 int generic_block_fiemap(struct inode *inode,
 433                          struct fiemap_extent_info *fieinfo, u64 start,
 434                          u64 len, get_block_t *get_block)
 435 {
 436         int ret;
 437         inode_lock(inode);
 438         ret = __generic_block_fiemap(inode, fieinfo, start, len, get_block);
 439         inode_unlock(inode);
 440         return ret;
 441 }
 442 EXPORT_SYMBOL(generic_block_fiemap);
 443
 444 #endif  /*  CONFIG_BLOCK  */
 445
 446 /*
 447  * This provides compatibility with legacy XFS pre-allocation ioctls
 448  * which predate the fallocate syscall.
 449  *
 450  * Only the l_start, l_len and l_whence fields of the 'struct space_resv'
 451  * are used here, rest are ignored.
 452  */
 453 int ioctl_preallocate(struct file *filp, void __user *argp)
 454 {
 455         struct inode *inode = file_inode(filp);
 456         struct space_resv sr;
 457
 458         if (copy_from_user(&sr, argp, sizeof(sr)))
 459                 return -EFAULT;
 460
 461         switch (sr.l_whence) {
 462         case SEEK_SET:
 463                 break;
 464         case SEEK_CUR:
 465                 sr.l_start += filp->f_pos;
 466                 break;
 467         case SEEK_END:
 468                 sr.l_start += i_size_read(inode);
 469                 break;
 470         default:
 471                 return -EINVAL;
 472         }
 473
 474         return vfs_fallocate(filp, FALLOC_FL_KEEP_SIZE, sr.l_start, sr.l_len);
 475 }
 476
 477 static int file_ioctl(struct file *filp, unsigned int cmd,
 478                 unsigned long arg)
 479 {
 480         struct inode *inode = file_inode(filp);
 481         int __user *p = (int __user *)arg;
 482
 483         switch (cmd) {
 484         case FIBMAP:
 485                 return ioctl_fibmap(filp, p);
 486         case FIONREAD:
 487                 return put_user(i_size_read(inode) - filp->f_pos, p);
 488         case FS_IOC_RESVSP:
 489         case FS_IOC_RESVSP64:
 490                 return ioctl_preallocate(filp, p);
 491         }
 492
 493         return vfs_ioctl(filp, cmd, arg);
 494 }
 495
 496 static int ioctl_fionbio(struct file *filp, int __user *argp)
 497 {
 498         unsigned int flag;
 499         int on, error;
 500
 501         error = get_user(on, argp);
 502         if (error)
 503                 return error;
 504         flag = O_NONBLOCK;
 505 #ifdef __sparc__
 506         /* SunOS compatibility item. */
 507         if (O_NONBLOCK != O_NDELAY)
 508                 flag |= O_NDELAY;
 509 #endif
 510         spin_lock(&filp->f_lock);
 511         if (on)
 512                 filp->f_flags |= flag;
 513         else
 514                 filp->f_flags &= ~flag;
 515         spin_unlock(&filp->f_lock);
 516         return error;
 517 }
 518
 519 static int ioctl_fioasync(unsigned int fd, struct file *filp,
 520                           int __user *argp)
 521 {
 522         unsigned int flag;
 523         int on, error;
 524
 525         error = get_user(on, argp);
 526         if (error)
 527                 return error;
 528         flag = on ? FASYNC : 0;
 529
 530         /* Did FASYNC state change ? */
 531         if ((flag ^ filp->f_flags) & FASYNC) {
 532                 if (filp->f_op->fasync)
 533                         /* fasync() adjusts filp->f_flags */
 534                         error = filp->f_op->fasync(fd, filp, on);
 535                 else
 536                         error = -ENOTTY;
 537         }
 538         return error < 0 ? error : 0;
 539 }
 540
 541 static int ioctl_fsfreeze(struct file *filp)
 542 {
 543         struct super_block *sb = file_inode(filp)->i_sb;
 544
 545         if (!capable(CAP_SYS_ADMIN))
 546                 return -EPERM;
 547
 548         /* If filesystem doesn't support freeze feature, return. */
 549         if (sb->s_op->freeze_fs == NULL && sb->s_op->freeze_super == NULL)
 550                 return -EOPNOTSUPP;
 551
 552         /* Freeze */
 553         if (sb->s_op->freeze_super)
 554                 return sb->s_op->freeze_super(sb);
 555         return freeze_super(sb);
 556 }
 557
 558 static int ioctl_fsthaw(struct file *filp)
 559 {
 560         struct super_block *sb = file_inode(filp)->i_sb;
 561
 562         if (!capable(CAP_SYS_ADMIN))
 563                 return -EPERM;
 564
 565         /* Thaw */
 566         if (sb->s_op->thaw_super)
 567                 return sb->s_op->thaw_super(sb);
 568         return thaw_super(sb);
 569 }
 570
 571 static long ioctl_file_dedupe_range(struct file *file, void __user *arg)
 572 {
 573         struct file_dedupe_range __user *argp = arg;
 574         struct file_dedupe_range *same = NULL;
 575         int ret;
 576         unsigned long size;
 577         u16 count;
 578
 579         if (get_user(count, &argp->dest_count)) {
 580                 ret = -EFAULT;
 581                 goto out;
 582         }
 583
 584         size = offsetof(struct file_dedupe_range __user, info[count]);
 585
 586         same = memdup_user(argp, size);
 587         if (IS_ERR(same)) {
 588                 ret = PTR_ERR(same);
 589                 same = NULL;
 590                 goto out;
 591         }
 592
 593         ret = vfs_dedupe_file_range(file, same);
 594         if (ret)
 595                 goto out;
 596
 597         ret = copy_to_user(argp, same, size);
 598         if (ret)
 599                 ret = -EFAULT;
 600
 601 out:
 602         kfree(same);
 603         return ret;
 604 }
 605
 606 /*
 607  * When you add any new common ioctls to the switches above and below
 608  * please update compat_sys_ioctl() too.
 609  *
 610  * do_vfs_ioctl() is not for drivers and not intended to be EXPORT_SYMBOL()'d.
 611  * It's just a simple helper for sys_ioctl and compat_sys_ioctl.
 612  */
 613 int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd,
 614              unsigned long arg)
 615 {
 616         int error = 0;
 617         int __user *argp = (int __user *)arg;
 618         struct inode *inode = file_inode(filp);
 619
 620         switch (cmd) {
 621         case FIOCLEX:
 622                 set_close_on_exec(fd, 1);
 623                 break;
 624
 625         case FIONCLEX:
 626                 set_close_on_exec(fd, 0);
 627                 break;
 628
 629         case FIONBIO:
 630                 error = ioctl_fionbio(filp, argp);
 631                 break;
 632
 633         case FIOASYNC:
 634                 error = ioctl_fioasync(fd, filp, argp);
 635                 break;
 636
 637         case FIOQSIZE:
 638                 if (S_ISDIR(inode->i_mode) || S_ISREG(inode->i_mode) ||
 639                     S_ISLNK(inode->i_mode)) {
 640                         loff_t res = inode_get_bytes(inode);
 641                         error = copy_to_user(argp, &res, sizeof(res)) ?
 642                                         -EFAULT : 0;
 643                 } else
 644                         error = -ENOTTY;
 645                 break;
 646
 647         case FIFREEZE:
 648                 error = ioctl_fsfreeze(filp);
 649                 break;
 650
 651         case FITHAW:
 652                 error = ioctl_fsthaw(filp);
 653                 break;
 654
 655         case FS_IOC_FIEMAP:
 656                 return ioctl_fiemap(filp, arg);
 657
 658         case FIGETBSZ:
 659                 return put_user(inode->i_sb->s_blocksize, argp);
 660
 661         case FICLONE:
 662                 return ioctl_file_clone(filp, arg, 0, 0, 0);
 663
 664         case FICLONERANGE:
 665                 return ioctl_file_clone_range(filp, argp);
 666
 667         case FIDEDUPERANGE:
 668                 return ioctl_file_dedupe_range(filp, argp);
 669
 670         default:
 671                 if (S_ISREG(inode->i_mode))
 672                         error = file_ioctl(filp, cmd, arg);
 673                 else
 674                         error = vfs_ioctl(filp, cmd, arg);
 675                 break;
 676         }
 677         return error;
 678 }
 679
 680 SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd, unsigned long, arg)
 681 {
 682         int error;
 683         struct fd f = fdget(fd);
 684
 685         if (!f.file)
 686                 return -EBADF;
 687         error = security_file_ioctl(f.file, cmd, arg);
 688         if (!error)
 689                 error = do_vfs_ioctl(f.file, fd, cmd, arg);
 690         fdput(f);
 691         return error;
 692 }