linux/fs/ioctl.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 *  linux/fs/ioctl.c
   4 *
   5 *  Copyright (C) 1991, 1992  Linus Torvalds
   6 */
   7
   8#include <linux/syscalls.h>
   9#include <linux/mm.h>
  10#include <linux/capability.h>
  11#include <linux/compat.h>
  12#include <linux/file.h>
  13#include <linux/fs.h>
  14#include <linux/security.h>
  15#include <linux/export.h>
  16#include <linux/uaccess.h>
  17#include <linux/writeback.h>
  18#include <linux/buffer_head.h>
  19#include <linux/falloc.h>
  20#include <linux/sched/signal.h>
  21#include <linux/fiemap.h>
  22
  23#include "internal.h"
  24
  25#include <asm/ioctls.h>
  26
  27/* So that the fiemap access checks can't overflow on 32 bit machines. */
  28#define FIEMAP_MAX_EXTENTS      (UINT_MAX / sizeof(struct fiemap_extent))
  29
  30/**
  31 * vfs_ioctl - call filesystem specific ioctl methods
  32 * @filp:       open file to invoke ioctl method on
  33 * @cmd:        ioctl command to execute
  34 * @arg:        command-specific argument for ioctl
  35 *
  36 * Invokes filesystem specific ->unlocked_ioctl, if one exists; otherwise
  37 * returns -ENOTTY.
  38 *
  39 * Returns 0 on success, -errno on error.
  40 */
  41long vfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
  42{
  43        int error = -ENOTTY;
  44
  45        if (!filp->f_op->unlocked_ioctl)
  46                goto out;
  47
  48        error = filp->f_op->unlocked_ioctl(filp, cmd, arg);
  49        if (error == -ENOIOCTLCMD)
  50                error = -ENOTTY;
  51 out:
  52        return error;
  53}
  54EXPORT_SYMBOL(vfs_ioctl);
  55
  56static int ioctl_fibmap(struct file *filp, int __user *p)
  57{
  58        struct inode *inode = file_inode(filp);
  59        struct super_block *sb = inode->i_sb;
  60        int error, ur_block;
  61        sector_t block;
  62
  63        if (!capable(CAP_SYS_RAWIO))
  64                return -EPERM;
  65
  66        error = get_user(ur_block, p);
  67        if (error)
  68                return error;
  69
  70        if (ur_block < 0)
  71                return -EINVAL;
  72
  73        block = ur_block;
  74        error = bmap(inode, &block);
  75
  76        if (block > INT_MAX) {
  77                error = -ERANGE;
  78                pr_warn_ratelimited("[%s/%d] FS: %s File: %pD4 would truncate fibmap result\n",
  79                                    current->comm, task_pid_nr(current),
  80                                    sb->s_id, filp);
  81        }
  82
  83        if (error)
  84                ur_block = 0;
  85        else
  86                ur_block = block;
  87
  88        if (put_user(ur_block, p))
  89                error = -EFAULT;
  90
  91        return error;
  92}
  93
  94/**
  95 * fiemap_fill_next_extent - Fiemap helper function
  96 * @fieinfo:    Fiemap context passed into ->fiemap
  97 * @logical:    Extent logical start offset, in bytes
  98 * @phys:       Extent physical start offset, in bytes
  99 * @len:        Extent length, in bytes
 100 * @flags:      FIEMAP_EXTENT flags that describe this extent
 101 *
 102 * Called from file system ->fiemap callback. Will populate extent
 103 * info as passed in via arguments and copy to user memory. On
 104 * success, extent count on fieinfo is incremented.
 105 *
 106 * Returns 0 on success, -errno on error, 1 if this was the last
 107 * extent that will fit in user array.
 108 */
 109#define SET_UNKNOWN_FLAGS       (FIEMAP_EXTENT_DELALLOC)
 110#define SET_NO_UNMOUNTED_IO_FLAGS       (FIEMAP_EXTENT_DATA_ENCRYPTED)
 111#define SET_NOT_ALIGNED_FLAGS   (FIEMAP_EXTENT_DATA_TAIL|FIEMAP_EXTENT_DATA_INLINE)
 112int fiemap_fill_next_extent(struct fiemap_extent_info *fieinfo, u64 logical,
 113                            u64 phys, u64 len, u32 flags)
 114{
 115        struct fiemap_extent extent;
 116        struct fiemap_extent __user *dest = fieinfo->fi_extents_start;
 117
 118        /* only count the extents */
 119        if (fieinfo->fi_extents_max == 0) {
 120                fieinfo->fi_extents_mapped++;
 121                return (flags & FIEMAP_EXTENT_LAST) ? 1 : 0;
 122        }
 123
 124        if (fieinfo->fi_extents_mapped >= fieinfo->fi_extents_max)
 125                return 1;
 126
 127        if (flags & SET_UNKNOWN_FLAGS)
 128                flags |= FIEMAP_EXTENT_UNKNOWN;
 129        if (flags & SET_NO_UNMOUNTED_IO_FLAGS)
 130                flags |= FIEMAP_EXTENT_ENCODED;
 131        if (flags & SET_NOT_ALIGNED_FLAGS)
 132                flags |= FIEMAP_EXTENT_NOT_ALIGNED;
 133
 134        memset(&extent, 0, sizeof(extent));
 135        extent.fe_logical = logical;
 136        extent.fe_physical = phys;
 137        extent.fe_length = len;
 138        extent.fe_flags = flags;
 139
 140        dest += fieinfo->fi_extents_mapped;
 141        if (copy_to_user(dest, &extent, sizeof(extent)))
 142                return -EFAULT;
 143
 144        fieinfo->fi_extents_mapped++;
 145        if (fieinfo->fi_extents_mapped == fieinfo->fi_extents_max)
 146                return 1;
 147        return (flags & FIEMAP_EXTENT_LAST) ? 1 : 0;
 148}
 149EXPORT_SYMBOL(fiemap_fill_next_extent);
 150
 151/**
 152 * fiemap_prep - check validity of requested flags for fiemap
 153 * @inode:      Inode to operate on
 154 * @fieinfo:    Fiemap context passed into ->fiemap
 155 * @start:      Start of the mapped range
 156 * @len:        Length of the mapped range, can be truncated by this function.
 157 * @supported_flags:    Set of fiemap flags that the file system understands
 158 *
 159 * This function must be called from each ->fiemap instance to validate the
 160 * fiemap request against the file system parameters.
 161 *
 162 * Returns 0 on success, or a negative error on failure.
 163 */
 164int fiemap_prep(struct inode *inode, struct fiemap_extent_info *fieinfo,
 165                u64 start, u64 *len, u32 supported_flags)
 166{
 167        u64 maxbytes = inode->i_sb->s_maxbytes;
 168        u32 incompat_flags;
 169        int ret = 0;
 170
 171        if (*len == 0)
 172                return -EINVAL;
 173        if (start > maxbytes)
 174                return -EFBIG;
 175
 176        /*
 177         * Shrink request scope to what the fs can actually handle.
 178         */
 179        if (*len > maxbytes || (maxbytes - *len) < start)
 180                *len = maxbytes - start;
 181
 182        supported_flags |= FIEMAP_FLAG_SYNC;
 183        supported_flags &= FIEMAP_FLAGS_COMPAT;
 184        incompat_flags = fieinfo->fi_flags & ~supported_flags;
 185        if (incompat_flags) {
 186                fieinfo->fi_flags = incompat_flags;
 187                return -EBADR;
 188        }
 189
 190        if (fieinfo->fi_flags & FIEMAP_FLAG_SYNC)
 191                ret = filemap_write_and_wait(inode->i_mapping);
 192        return ret;
 193}
 194EXPORT_SYMBOL(fiemap_prep);
 195
 196static int ioctl_fiemap(struct file *filp, struct fiemap __user *ufiemap)
 197{
 198        struct fiemap fiemap;
 199        struct fiemap_extent_info fieinfo = { 0, };
 200        struct inode *inode = file_inode(filp);
 201        int error;
 202
 203        if (!inode->i_op->fiemap)
 204                return -EOPNOTSUPP;
 205
 206        if (copy_from_user(&fiemap, ufiemap, sizeof(fiemap)))
 207                return -EFAULT;
 208
 209        if (fiemap.fm_extent_count > FIEMAP_MAX_EXTENTS)
 210                return -EINVAL;
 211
 212        fieinfo.fi_flags = fiemap.fm_flags;
 213        fieinfo.fi_extents_max = fiemap.fm_extent_count;
 214        fieinfo.fi_extents_start = ufiemap->fm_extents;
 215
 216        error = inode->i_op->fiemap(inode, &fieinfo, fiemap.fm_start,
 217                        fiemap.fm_length);
 218
 219        fiemap.fm_flags = fieinfo.fi_flags;
 220        fiemap.fm_mapped_extents = fieinfo.fi_extents_mapped;
 221        if (copy_to_user(ufiemap, &fiemap, sizeof(fiemap)))
 222                error = -EFAULT;
 223
 224        return error;
 225}
 226
 227static long ioctl_file_clone(struct file *dst_file, unsigned long srcfd,
 228                             u64 off, u64 olen, u64 destoff)
 229{
 230        struct fd src_file = fdget(srcfd);
 231        loff_t cloned;
 232        int ret;
 233
 234        if (!src_file.file)
 235                return -EBADF;
 236        ret = -EXDEV;
 237        if (src_file.file->f_path.mnt != dst_file->f_path.mnt)
 238                goto fdput;
 239        cloned = vfs_clone_file_range(src_file.file, off, dst_file, destoff,
 240                                      olen, 0);
 241        if (cloned < 0)
 242                ret = cloned;
 243        else if (olen && cloned != olen)
 244                ret = -EINVAL;
 245        else
 246                ret = 0;
 247fdput:
 248        fdput(src_file);
 249        return ret;
 250}
 251
 252static long ioctl_file_clone_range(struct file *file,
 253                                   struct file_clone_range __user *argp)
 254{
 255        struct file_clone_range args;
 256
 257        if (copy_from_user(&args, argp, sizeof(args)))
 258                return -EFAULT;
 259        return ioctl_file_clone(file, args.src_fd, args.src_offset,
 260                                args.src_length, args.dest_offset);
 261}
 262
 263#ifdef CONFIG_BLOCK
 264
 265static inline sector_t logical_to_blk(struct inode *inode, loff_t offset)
 266{
 267        return (offset >> inode->i_blkbits);
 268}
 269
 270static inline loff_t blk_to_logical(struct inode *inode, sector_t blk)
 271{
 272        return (blk << inode->i_blkbits);
 273}
 274
 275/**
 276 * __generic_block_fiemap - FIEMAP for block based inodes (no locking)
 277 * @inode: the inode to map
 278 * @fieinfo: the fiemap info struct that will be passed back to userspace
 279 * @start: where to start mapping in the inode
 280 * @len: how much space to map
 281 * @get_block: the fs's get_block function
 282 *
 283 * This does FIEMAP for block based inodes.  Basically it will just loop
 284 * through get_block until we hit the number of extents we want to map, or we
 285 * go past the end of the file and hit a hole.
 286 *
 287 * If it is possible to have data blocks beyond a hole past @inode->i_size, then
 288 * please do not use this function, it will stop at the first unmapped block
 289 * beyond i_size.
 290 *
 291 * If you use this function directly, you need to do your own locking. Use
 292 * generic_block_fiemap if you want the locking done for you.
 293 */
 294static int __generic_block_fiemap(struct inode *inode,
 295                           struct fiemap_extent_info *fieinfo, loff_t start,
 296                           loff_t len, get_block_t *get_block)
 297{
 298        struct buffer_head map_bh;
 299        sector_t start_blk, last_blk;
 300        loff_t isize = i_size_read(inode);
 301        u64 logical = 0, phys = 0, size = 0;
 302        u32 flags = FIEMAP_EXTENT_MERGED;
 303        bool past_eof = false, whole_file = false;
 304        int ret = 0;
 305
 306        ret = fiemap_prep(inode, fieinfo, start, &len, FIEMAP_FLAG_SYNC);
 307        if (ret)
 308                return ret;
 309
 310        /*
 311         * Either the i_mutex or other appropriate locking needs to be held
 312         * since we expect isize to not change at all through the duration of
 313         * this call.
 314         */
 315        if (len >= isize) {
 316                whole_file = true;
 317                len = isize;
 318        }
 319
 320        /*
 321         * Some filesystems can't deal with being asked to map less than
 322         * blocksize, so make sure our len is at least block length.
 323         */
 324        if (logical_to_blk(inode, len) == 0)
 325                len = blk_to_logical(inode, 1);
 326
 327        start_blk = logical_to_blk(inode, start);
 328        last_blk = logical_to_blk(inode, start + len - 1);
 329
 330        do {
 331                /*
 332                 * we set b_size to the total size we want so it will map as
 333                 * many contiguous blocks as possible at once
 334                 */
 335                memset(&map_bh, 0, sizeof(struct buffer_head));
 336                map_bh.b_size = len;
 337
 338                ret = get_block(inode, start_blk, &map_bh, 0);
 339                if (ret)
 340                        break;
 341
 342                /* HOLE */
 343                if (!buffer_mapped(&map_bh)) {
 344                        start_blk++;
 345
 346                        /*
 347                         * We want to handle the case where there is an
 348                         * allocated block at the front of the file, and then
 349                         * nothing but holes up to the end of the file properly,
 350                         * to make sure that extent at the front gets properly
 351                         * marked with FIEMAP_EXTENT_LAST
 352                         */
 353                        if (!past_eof &&
 354                            blk_to_logical(inode, start_blk) >= isize)
 355                                past_eof = 1;
 356
 357                        /*
 358                         * First hole after going past the EOF, this is our
 359                         * last extent
 360                         */
 361                        if (past_eof && size) {
 362                                flags = FIEMAP_EXTENT_MERGED|FIEMAP_EXTENT_LAST;
 363                                ret = fiemap_fill_next_extent(fieinfo, logical,
 364                                                              phys, size,
 365                                                              flags);
 366                        } else if (size) {
 367                                ret = fiemap_fill_next_extent(fieinfo, logical,
 368                                                              phys, size, flags);
 369                                size = 0;
 370                        }
 371
 372                        /* if we have holes up to/past EOF then we're done */
 373                        if (start_blk > last_blk || past_eof || ret)
 374                                break;
 375                } else {
 376                        /*
 377                         * We have gone over the length of what we wanted to
 378                         * map, and it wasn't the entire file, so add the extent
 379                         * we got last time and exit.
 380                         *
 381                         * This is for the case where say we want to map all the
 382                         * way up to the second to the last block in a file, but
 383                         * the last block is a hole, making the second to last
 384                         * block FIEMAP_EXTENT_LAST.  In this case we want to
 385                         * see if there is a hole after the second to last block
 386                         * so we can mark it properly.  If we found data after
 387                         * we exceeded the length we were requesting, then we
 388                         * are good to go, just add the extent to the fieinfo
 389                         * and break
 390                         */
 391                        if (start_blk > last_blk && !whole_file) {
 392                                ret = fiemap_fill_next_extent(fieinfo, logical,
 393                                                              phys, size,
 394                                                              flags);
 395                                break;
 396                        }
 397
 398                        /*
 399                         * if size != 0 then we know we already have an extent
 400                         * to add, so add it.
 401                         */
 402                        if (size) {
 403                                ret = fiemap_fill_next_extent(fieinfo, logical,
 404                                                              phys, size,
 405                                                              flags);
 406                                if (ret)
 407                                        break;
 408                        }
 409
 410                        logical = blk_to_logical(inode, start_blk);
 411                        phys = blk_to_logical(inode, map_bh.b_blocknr);
 412                        size = map_bh.b_size;
 413                        flags = FIEMAP_EXTENT_MERGED;
 414
 415                        start_blk += logical_to_blk(inode, size);
 416
 417                        /*
 418                         * If we are past the EOF, then we need to make sure as
 419                         * soon as we find a hole that the last extent we found
 420                         * is marked with FIEMAP_EXTENT_LAST
 421                         */
 422                        if (!past_eof && logical + size >= isize)
 423                                past_eof = true;
 424                }
 425                cond_resched();
 426                if (fatal_signal_pending(current)) {
 427                        ret = -EINTR;
 428                        break;
 429                }
 430
 431        } while (1);
 432
 433        /* If ret is 1 then we just hit the end of the extent array */
 434        if (ret == 1)
 435                ret = 0;
 436
 437        return ret;
 438}
 439
 440/**
 441 * generic_block_fiemap - FIEMAP for block based inodes
 442 * @inode: The inode to map
 443 * @fieinfo: The mapping information
 444 * @start: The initial block to map
 445 * @len: The length of the extect to attempt to map
 446 * @get_block: The block mapping function for the fs
 447 *
 448 * Calls __generic_block_fiemap to map the inode, after taking
 449 * the inode's mutex lock.
 450 */
 451
 452int generic_block_fiemap(struct inode *inode,
 453                         struct fiemap_extent_info *fieinfo, u64 start,
 454                         u64 len, get_block_t *get_block)
 455{
 456        int ret;
 457        inode_lock(inode);
 458        ret = __generic_block_fiemap(inode, fieinfo, start, len, get_block);
 459        inode_unlock(inode);
 460        return ret;
 461}
 462EXPORT_SYMBOL(generic_block_fiemap);
 463
 464#endif  /*  CONFIG_BLOCK  */
 465
 466/*
 467 * This provides compatibility with legacy XFS pre-allocation ioctls
 468 * which predate the fallocate syscall.
 469 *
 470 * Only the l_start, l_len and l_whence fields of the 'struct space_resv'
 471 * are used here, rest are ignored.
 472 */
 473static int ioctl_preallocate(struct file *filp, int mode, void __user *argp)
 474{
 475        struct inode *inode = file_inode(filp);
 476        struct space_resv sr;
 477
 478        if (copy_from_user(&sr, argp, sizeof(sr)))
 479                return -EFAULT;
 480
 481        switch (sr.l_whence) {
 482        case SEEK_SET:
 483                break;
 484        case SEEK_CUR:
 485                sr.l_start += filp->f_pos;
 486                break;
 487        case SEEK_END:
 488                sr.l_start += i_size_read(inode);
 489                break;
 490        default:
 491                return -EINVAL;
 492        }
 493
 494        return vfs_fallocate(filp, mode | FALLOC_FL_KEEP_SIZE, sr.l_start,
 495                        sr.l_len);
 496}
 497
 498/* on ia32 l_start is on a 32-bit boundary */
 499#if defined CONFIG_COMPAT && defined(CONFIG_X86_64)
 500/* just account for different alignment */
 501static int compat_ioctl_preallocate(struct file *file, int mode,
 502                                    struct space_resv_32 __user *argp)
 503{
 504        struct inode *inode = file_inode(file);
 505        struct space_resv_32 sr;
 506
 507        if (copy_from_user(&sr, argp, sizeof(sr)))
 508                return -EFAULT;
 509
 510        switch (sr.l_whence) {
 511        case SEEK_SET:
 512                break;
 513        case SEEK_CUR:
 514                sr.l_start += file->f_pos;
 515                break;
 516        case SEEK_END:
 517                sr.l_start += i_size_read(inode);
 518                break;
 519        default:
 520                return -EINVAL;
 521        }
 522
 523        return vfs_fallocate(file, mode | FALLOC_FL_KEEP_SIZE, sr.l_start, sr.l_len);
 524}
 525#endif
 526
 527static int file_ioctl(struct file *filp, unsigned int cmd, int __user *p)
 528{
 529        switch (cmd) {
 530        case FIBMAP:
 531                return ioctl_fibmap(filp, p);
 532        case FS_IOC_RESVSP:
 533        case FS_IOC_RESVSP64:
 534                return ioctl_preallocate(filp, 0, p);
 535        case FS_IOC_UNRESVSP:
 536        case FS_IOC_UNRESVSP64:
 537                return ioctl_preallocate(filp, FALLOC_FL_PUNCH_HOLE, p);
 538        case FS_IOC_ZERO_RANGE:
 539                return ioctl_preallocate(filp, FALLOC_FL_ZERO_RANGE, p);
 540        }
 541
 542        return -ENOIOCTLCMD;
 543}
 544
 545static int ioctl_fionbio(struct file *filp, int __user *argp)
 546{
 547        unsigned int flag;
 548        int on, error;
 549
 550        error = get_user(on, argp);
 551        if (error)
 552                return error;
 553        flag = O_NONBLOCK;
 554#ifdef __sparc__
 555        /* SunOS compatibility item. */
 556        if (O_NONBLOCK != O_NDELAY)
 557                flag |= O_NDELAY;
 558#endif
 559        spin_lock(&filp->f_lock);
 560        if (on)
 561                filp->f_flags |= flag;
 562        else
 563                filp->f_flags &= ~flag;
 564        spin_unlock(&filp->f_lock);
 565        return error;
 566}
 567
 568static int ioctl_fioasync(unsigned int fd, struct file *filp,
 569                          int __user *argp)
 570{
 571        unsigned int flag;
 572        int on, error;
 573
 574        error = get_user(on, argp);
 575        if (error)
 576                return error;
 577        flag = on ? FASYNC : 0;
 578
 579        /* Did FASYNC state change ? */
 580        if ((flag ^ filp->f_flags) & FASYNC) {
 581                if (filp->f_op->fasync)
 582                        /* fasync() adjusts filp->f_flags */
 583                        error = filp->f_op->fasync(fd, filp, on);
 584                else
 585                        error = -ENOTTY;
 586        }
 587        return error < 0 ? error : 0;
 588}
 589
 590static int ioctl_fsfreeze(struct file *filp)
 591{
 592        struct super_block *sb = file_inode(filp)->i_sb;
 593
 594        if (!ns_capable(sb->s_user_ns, CAP_SYS_ADMIN))
 595                return -EPERM;
 596
 597        /* If filesystem doesn't support freeze feature, return. */
 598        if (sb->s_op->freeze_fs == NULL && sb->s_op->freeze_super == NULL)
 599                return -EOPNOTSUPP;
 600
 601        /* Freeze */
 602        if (sb->s_op->freeze_super)
 603                return sb->s_op->freeze_super(sb);
 604        return freeze_super(sb);
 605}
 606
 607static int ioctl_fsthaw(struct file *filp)
 608{
 609        struct super_block *sb = file_inode(filp)->i_sb;
 610
 611        if (!ns_capable(sb->s_user_ns, CAP_SYS_ADMIN))
 612                return -EPERM;
 613
 614        /* Thaw */
 615        if (sb->s_op->thaw_super)
 616                return sb->s_op->thaw_super(sb);
 617        return thaw_super(sb);
 618}
 619
 620static int ioctl_file_dedupe_range(struct file *file,
 621                                   struct file_dedupe_range __user *argp)
 622{
 623        struct file_dedupe_range *same = NULL;
 624        int ret;
 625        unsigned long size;
 626        u16 count;
 627
 628        if (get_user(count, &argp->dest_count)) {
 629                ret = -EFAULT;
 630                goto out;
 631        }
 632
 633        size = offsetof(struct file_dedupe_range __user, info[count]);
 634        if (size > PAGE_SIZE) {
 635                ret = -ENOMEM;
 636                goto out;
 637        }
 638
 639        same = memdup_user(argp, size);
 640        if (IS_ERR(same)) {
 641                ret = PTR_ERR(same);
 642                same = NULL;
 643                goto out;
 644        }
 645
 646        same->dest_count = count;
 647        ret = vfs_dedupe_file_range(file, same);
 648        if (ret)
 649                goto out;
 650
 651        ret = copy_to_user(argp, same, size);
 652        if (ret)
 653                ret = -EFAULT;
 654
 655out:
 656        kfree(same);
 657        return ret;
 658}
 659
 660/*
 661 * do_vfs_ioctl() is not for drivers and not intended to be EXPORT_SYMBOL()'d.
 662 * It's just a simple helper for sys_ioctl and compat_sys_ioctl.
 663 *
 664 * When you add any new common ioctls to the switches above and below,
 665 * please ensure they have compatible arguments in compat mode.
 666 */
 667static int do_vfs_ioctl(struct file *filp, unsigned int fd,
 668                        unsigned int cmd, unsigned long arg)
 669{
 670        void __user *argp = (void __user *)arg;
 671        struct inode *inode = file_inode(filp);
 672
 673        switch (cmd) {
 674        case FIOCLEX:
 675                set_close_on_exec(fd, 1);
 676                return 0;
 677
 678        case FIONCLEX:
 679                set_close_on_exec(fd, 0);
 680                return 0;
 681
 682        case FIONBIO:
 683                return ioctl_fionbio(filp, argp);
 684
 685        case FIOASYNC:
 686                return ioctl_fioasync(fd, filp, argp);
 687
 688        case FIOQSIZE:
 689                if (S_ISDIR(inode->i_mode) || S_ISREG(inode->i_mode) ||
 690                    S_ISLNK(inode->i_mode)) {
 691                        loff_t res = inode_get_bytes(inode);
 692                        return copy_to_user(argp, &res, sizeof(res)) ?
 693                                            -EFAULT : 0;
 694                }
 695
 696                return -ENOTTY;
 697
 698        case FIFREEZE:
 699                return ioctl_fsfreeze(filp);
 700
 701        case FITHAW:
 702                return ioctl_fsthaw(filp);
 703
 704        case FS_IOC_FIEMAP:
 705                return ioctl_fiemap(filp, argp);
 706
 707        case FIGETBSZ:
 708                /* anon_bdev filesystems may not have a block size */
 709                if (!inode->i_sb->s_blocksize)
 710                        return -EINVAL;
 711
 712                return put_user(inode->i_sb->s_blocksize, (int __user *)argp);
 713
 714        case FICLONE:
 715                return ioctl_file_clone(filp, arg, 0, 0, 0);
 716
 717        case FICLONERANGE:
 718                return ioctl_file_clone_range(filp, argp);
 719
 720        case FIDEDUPERANGE:
 721                return ioctl_file_dedupe_range(filp, argp);
 722
 723        case FIONREAD:
 724                if (!S_ISREG(inode->i_mode))
 725                        return vfs_ioctl(filp, cmd, arg);
 726
 727                return put_user(i_size_read(inode) - filp->f_pos,
 728                                (int __user *)argp);
 729
 730        default:
 731                if (S_ISREG(inode->i_mode))
 732                        return file_ioctl(filp, cmd, argp);
 733                break;
 734        }
 735
 736        return -ENOIOCTLCMD;
 737}
 738
 739SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd, unsigned long, arg)
 740{
 741        struct fd f = fdget(fd);
 742        int error;
 743
 744        if (!f.file)
 745                return -EBADF;
 746
 747        error = security_file_ioctl(f.file, cmd, arg);
 748        if (error)
 749                goto out;
 750
 751        error = do_vfs_ioctl(f.file, fd, cmd, arg);
 752        if (error == -ENOIOCTLCMD)
 753                error = vfs_ioctl(f.file, cmd, arg);
 754
 755out:
 756        fdput(f);
 757        return error;
 758}
 759
 760#ifdef CONFIG_COMPAT
 761/**
 762 * compat_ptr_ioctl - generic implementation of .compat_ioctl file operation
 763 *
 764 * This is not normally called as a function, but instead set in struct
 765 * file_operations as
 766 *
 767 *     .compat_ioctl = compat_ptr_ioctl,
 768 *
 769 * On most architectures, the compat_ptr_ioctl() just passes all arguments
 770 * to the corresponding ->ioctl handler. The exception is arch/s390, where
 771 * compat_ptr() clears the top bit of a 32-bit pointer value, so user space
 772 * pointers to the second 2GB alias the first 2GB, as is the case for
 773 * native 32-bit s390 user space.
 774 *
 775 * The compat_ptr_ioctl() function must therefore be used only with ioctl
 776 * functions that either ignore the argument or pass a pointer to a
 777 * compatible data type.
 778 *
 779 * If any ioctl command handled by fops->unlocked_ioctl passes a plain
 780 * integer instead of a pointer, or any of the passed data types
 781 * is incompatible between 32-bit and 64-bit architectures, a proper
 782 * handler is required instead of compat_ptr_ioctl.
 783 */
 784long compat_ptr_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 785{
 786        if (!file->f_op->unlocked_ioctl)
 787                return -ENOIOCTLCMD;
 788
 789        return file->f_op->unlocked_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
 790}
 791EXPORT_SYMBOL(compat_ptr_ioctl);
 792
 793COMPAT_SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd,
 794                       compat_ulong_t, arg)
 795{
 796        struct fd f = fdget(fd);
 797        int error;
 798
 799        if (!f.file)
 800                return -EBADF;
 801
 802        /* RED-PEN how should LSM module know it's handling 32bit? */
 803        error = security_file_ioctl(f.file, cmd, arg);
 804        if (error)
 805                goto out;
 806
 807        switch (cmd) {
 808        /* FICLONE takes an int argument, so don't use compat_ptr() */
 809        case FICLONE:
 810                error = ioctl_file_clone(f.file, arg, 0, 0, 0);
 811                break;
 812
 813#if defined(CONFIG_X86_64)
 814        /* these get messy on amd64 due to alignment differences */
 815        case FS_IOC_RESVSP_32:
 816        case FS_IOC_RESVSP64_32:
 817                error = compat_ioctl_preallocate(f.file, 0, compat_ptr(arg));
 818                break;
 819        case FS_IOC_UNRESVSP_32:
 820        case FS_IOC_UNRESVSP64_32:
 821                error = compat_ioctl_preallocate(f.file, FALLOC_FL_PUNCH_HOLE,
 822                                compat_ptr(arg));
 823                break;
 824        case FS_IOC_ZERO_RANGE_32:
 825                error = compat_ioctl_preallocate(f.file, FALLOC_FL_ZERO_RANGE,
 826                                compat_ptr(arg));
 827                break;
 828#endif
 829
 830        /*
 831         * everything else in do_vfs_ioctl() takes either a compatible
 832         * pointer argument or no argument -- call it with a modified
 833         * argument.
 834         */
 835        default:
 836                error = do_vfs_ioctl(f.file, fd, cmd,
 837                                     (unsigned long)compat_ptr(arg));
 838                if (error != -ENOIOCTLCMD)
 839                        break;
 840
 841                if (f.file->f_op->compat_ioctl)
 842                        error = f.file->f_op->compat_ioctl(f.file, cmd, arg);
 843                if (error == -ENOIOCTLCMD)
 844                        error = -ENOTTY;
 845                break;
 846        }
 847
 848 out:
 849        fdput(f);
 850
 851        return error;
 852}
 853#endif
 854