linux/block/ioctl.c
<<
>>
Prefs
   1// SPDX-License-Identifier: GPL-2.0
   2#include <linux/capability.h>
   3#include <linux/compat.h>
   4#include <linux/blkdev.h>
   5#include <linux/export.h>
   6#include <linux/gfp.h>
   7#include <linux/blkpg.h>
   8#include <linux/hdreg.h>
   9#include <linux/backing-dev.h>
  10#include <linux/fs.h>
  11#include <linux/blktrace_api.h>
  12#include <linux/pr.h>
  13#include <linux/uaccess.h>
  14#include "blk.h"
  15
  16static int blkpg_do_ioctl(struct block_device *bdev,
  17                          struct blkpg_partition __user *upart, int op)
  18{
  19        struct gendisk *disk = bdev->bd_disk;
  20        struct blkpg_partition p;
  21        long long start, length;
  22
  23        if (!capable(CAP_SYS_ADMIN))
  24                return -EACCES;
  25        if (copy_from_user(&p, upart, sizeof(struct blkpg_partition)))
  26                return -EFAULT;
  27        if (bdev_is_partition(bdev))
  28                return -EINVAL;
  29
  30        if (p.pno <= 0)
  31                return -EINVAL;
  32
  33        if (op == BLKPG_DEL_PARTITION)
  34                return bdev_del_partition(disk, p.pno);
  35
  36        start = p.start >> SECTOR_SHIFT;
  37        length = p.length >> SECTOR_SHIFT;
  38
  39        switch (op) {
  40        case BLKPG_ADD_PARTITION:
  41                /* check if partition is aligned to blocksize */
  42                if (p.start & (bdev_logical_block_size(bdev) - 1))
  43                        return -EINVAL;
  44                return bdev_add_partition(disk, p.pno, start, length);
  45        case BLKPG_RESIZE_PARTITION:
  46                return bdev_resize_partition(disk, p.pno, start, length);
  47        default:
  48                return -EINVAL;
  49        }
  50}
  51
  52static int blkpg_ioctl(struct block_device *bdev,
  53                       struct blkpg_ioctl_arg __user *arg)
  54{
  55        struct blkpg_partition __user *udata;
  56        int op;
  57
  58        if (get_user(op, &arg->op) || get_user(udata, &arg->data))
  59                return -EFAULT;
  60
  61        return blkpg_do_ioctl(bdev, udata, op);
  62}
  63
  64#ifdef CONFIG_COMPAT
  65struct compat_blkpg_ioctl_arg {
  66        compat_int_t op;
  67        compat_int_t flags;
  68        compat_int_t datalen;
  69        compat_caddr_t data;
  70};
  71
  72static int compat_blkpg_ioctl(struct block_device *bdev,
  73                              struct compat_blkpg_ioctl_arg __user *arg)
  74{
  75        compat_caddr_t udata;
  76        int op;
  77
  78        if (get_user(op, &arg->op) || get_user(udata, &arg->data))
  79                return -EFAULT;
  80
  81        return blkpg_do_ioctl(bdev, compat_ptr(udata), op);
  82}
  83#endif
  84
  85static int blkdev_reread_part(struct block_device *bdev, fmode_t mode)
  86{
  87        struct block_device *tmp;
  88
  89        if (!disk_part_scan_enabled(bdev->bd_disk) || bdev_is_partition(bdev))
  90                return -EINVAL;
  91        if (!capable(CAP_SYS_ADMIN))
  92                return -EACCES;
  93        if (bdev->bd_disk->open_partitions)
  94                return -EBUSY;
  95
  96        /*
  97         * Reopen the device to revalidate the driver state and force a
  98         * partition rescan.
  99         */
 100        mode &= ~FMODE_EXCL;
 101        set_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state);
 102
 103        tmp = blkdev_get_by_dev(bdev->bd_dev, mode, NULL);
 104        if (IS_ERR(tmp))
 105                return PTR_ERR(tmp);
 106        blkdev_put(tmp, mode);
 107        return 0;
 108}
 109
 110static int blk_ioctl_discard(struct block_device *bdev, fmode_t mode,
 111                unsigned long arg, unsigned long flags)
 112{
 113        uint64_t range[2];
 114        uint64_t start, len;
 115        struct request_queue *q = bdev_get_queue(bdev);
 116        int err;
 117
 118        if (!(mode & FMODE_WRITE))
 119                return -EBADF;
 120
 121        if (!blk_queue_discard(q))
 122                return -EOPNOTSUPP;
 123
 124        if (copy_from_user(range, (void __user *)arg, sizeof(range)))
 125                return -EFAULT;
 126
 127        start = range[0];
 128        len = range[1];
 129
 130        if (start & 511)
 131                return -EINVAL;
 132        if (len & 511)
 133                return -EINVAL;
 134
 135        if (start + len > i_size_read(bdev->bd_inode))
 136                return -EINVAL;
 137
 138        err = truncate_bdev_range(bdev, mode, start, start + len - 1);
 139        if (err)
 140                return err;
 141
 142        return blkdev_issue_discard(bdev, start >> 9, len >> 9,
 143                                    GFP_KERNEL, flags);
 144}
 145
 146static int blk_ioctl_zeroout(struct block_device *bdev, fmode_t mode,
 147                unsigned long arg)
 148{
 149        uint64_t range[2];
 150        uint64_t start, end, len;
 151        int err;
 152
 153        if (!(mode & FMODE_WRITE))
 154                return -EBADF;
 155
 156        if (copy_from_user(range, (void __user *)arg, sizeof(range)))
 157                return -EFAULT;
 158
 159        start = range[0];
 160        len = range[1];
 161        end = start + len - 1;
 162
 163        if (start & 511)
 164                return -EINVAL;
 165        if (len & 511)
 166                return -EINVAL;
 167        if (end >= (uint64_t)i_size_read(bdev->bd_inode))
 168                return -EINVAL;
 169        if (end < start)
 170                return -EINVAL;
 171
 172        /* Invalidate the page cache, including dirty pages */
 173        err = truncate_bdev_range(bdev, mode, start, end);
 174        if (err)
 175                return err;
 176
 177        return blkdev_issue_zeroout(bdev, start >> 9, len >> 9, GFP_KERNEL,
 178                        BLKDEV_ZERO_NOUNMAP);
 179}
 180
 181static int put_ushort(unsigned short __user *argp, unsigned short val)
 182{
 183        return put_user(val, argp);
 184}
 185
 186static int put_int(int __user *argp, int val)
 187{
 188        return put_user(val, argp);
 189}
 190
 191static int put_uint(unsigned int __user *argp, unsigned int val)
 192{
 193        return put_user(val, argp);
 194}
 195
 196static int put_long(long __user *argp, long val)
 197{
 198        return put_user(val, argp);
 199}
 200
 201static int put_ulong(unsigned long __user *argp, unsigned long val)
 202{
 203        return put_user(val, argp);
 204}
 205
 206static int put_u64(u64 __user *argp, u64 val)
 207{
 208        return put_user(val, argp);
 209}
 210
 211#ifdef CONFIG_COMPAT
 212static int compat_put_long(compat_long_t __user *argp, long val)
 213{
 214        return put_user(val, argp);
 215}
 216
 217static int compat_put_ulong(compat_ulong_t __user *argp, compat_ulong_t val)
 218{
 219        return put_user(val, argp);
 220}
 221#endif
 222
 223#ifdef CONFIG_COMPAT
 224/*
 225 * This is the equivalent of compat_ptr_ioctl(), to be used by block
 226 * drivers that implement only commands that are completely compatible
 227 * between 32-bit and 64-bit user space
 228 */
 229int blkdev_compat_ptr_ioctl(struct block_device *bdev, fmode_t mode,
 230                        unsigned cmd, unsigned long arg)
 231{
 232        struct gendisk *disk = bdev->bd_disk;
 233
 234        if (disk->fops->ioctl)
 235                return disk->fops->ioctl(bdev, mode, cmd,
 236                                         (unsigned long)compat_ptr(arg));
 237
 238        return -ENOIOCTLCMD;
 239}
 240EXPORT_SYMBOL(blkdev_compat_ptr_ioctl);
 241#endif
 242
 243static int blkdev_pr_register(struct block_device *bdev,
 244                struct pr_registration __user *arg)
 245{
 246        const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
 247        struct pr_registration reg;
 248
 249        if (!capable(CAP_SYS_ADMIN))
 250                return -EPERM;
 251        if (!ops || !ops->pr_register)
 252                return -EOPNOTSUPP;
 253        if (copy_from_user(&reg, arg, sizeof(reg)))
 254                return -EFAULT;
 255
 256        if (reg.flags & ~PR_FL_IGNORE_KEY)
 257                return -EOPNOTSUPP;
 258        return ops->pr_register(bdev, reg.old_key, reg.new_key, reg.flags);
 259}
 260
 261static int blkdev_pr_reserve(struct block_device *bdev,
 262                struct pr_reservation __user *arg)
 263{
 264        const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
 265        struct pr_reservation rsv;
 266
 267        if (!capable(CAP_SYS_ADMIN))
 268                return -EPERM;
 269        if (!ops || !ops->pr_reserve)
 270                return -EOPNOTSUPP;
 271        if (copy_from_user(&rsv, arg, sizeof(rsv)))
 272                return -EFAULT;
 273
 274        if (rsv.flags & ~PR_FL_IGNORE_KEY)
 275                return -EOPNOTSUPP;
 276        return ops->pr_reserve(bdev, rsv.key, rsv.type, rsv.flags);
 277}
 278
 279static int blkdev_pr_release(struct block_device *bdev,
 280                struct pr_reservation __user *arg)
 281{
 282        const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
 283        struct pr_reservation rsv;
 284
 285        if (!capable(CAP_SYS_ADMIN))
 286                return -EPERM;
 287        if (!ops || !ops->pr_release)
 288                return -EOPNOTSUPP;
 289        if (copy_from_user(&rsv, arg, sizeof(rsv)))
 290                return -EFAULT;
 291
 292        if (rsv.flags)
 293                return -EOPNOTSUPP;
 294        return ops->pr_release(bdev, rsv.key, rsv.type);
 295}
 296
 297static int blkdev_pr_preempt(struct block_device *bdev,
 298                struct pr_preempt __user *arg, bool abort)
 299{
 300        const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
 301        struct pr_preempt p;
 302
 303        if (!capable(CAP_SYS_ADMIN))
 304                return -EPERM;
 305        if (!ops || !ops->pr_preempt)
 306                return -EOPNOTSUPP;
 307        if (copy_from_user(&p, arg, sizeof(p)))
 308                return -EFAULT;
 309
 310        if (p.flags)
 311                return -EOPNOTSUPP;
 312        return ops->pr_preempt(bdev, p.old_key, p.new_key, p.type, abort);
 313}
 314
 315static int blkdev_pr_clear(struct block_device *bdev,
 316                struct pr_clear __user *arg)
 317{
 318        const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
 319        struct pr_clear c;
 320
 321        if (!capable(CAP_SYS_ADMIN))
 322                return -EPERM;
 323        if (!ops || !ops->pr_clear)
 324                return -EOPNOTSUPP;
 325        if (copy_from_user(&c, arg, sizeof(c)))
 326                return -EFAULT;
 327
 328        if (c.flags)
 329                return -EOPNOTSUPP;
 330        return ops->pr_clear(bdev, c.key);
 331}
 332
 333static int blkdev_flushbuf(struct block_device *bdev, fmode_t mode,
 334                unsigned cmd, unsigned long arg)
 335{
 336        if (!capable(CAP_SYS_ADMIN))
 337                return -EACCES;
 338        fsync_bdev(bdev);
 339        invalidate_bdev(bdev);
 340        return 0;
 341}
 342
 343static int blkdev_roset(struct block_device *bdev, fmode_t mode,
 344                unsigned cmd, unsigned long arg)
 345{
 346        int ret, n;
 347
 348        if (!capable(CAP_SYS_ADMIN))
 349                return -EACCES;
 350
 351        if (get_user(n, (int __user *)arg))
 352                return -EFAULT;
 353        if (bdev->bd_disk->fops->set_read_only) {
 354                ret = bdev->bd_disk->fops->set_read_only(bdev, n);
 355                if (ret)
 356                        return ret;
 357        }
 358        bdev->bd_read_only = n;
 359        return 0;
 360}
 361
 362static int blkdev_getgeo(struct block_device *bdev,
 363                struct hd_geometry __user *argp)
 364{
 365        struct gendisk *disk = bdev->bd_disk;
 366        struct hd_geometry geo;
 367        int ret;
 368
 369        if (!argp)
 370                return -EINVAL;
 371        if (!disk->fops->getgeo)
 372                return -ENOTTY;
 373
 374        /*
 375         * We need to set the startsect first, the driver may
 376         * want to override it.
 377         */
 378        memset(&geo, 0, sizeof(geo));
 379        geo.start = get_start_sect(bdev);
 380        ret = disk->fops->getgeo(bdev, &geo);
 381        if (ret)
 382                return ret;
 383        if (copy_to_user(argp, &geo, sizeof(geo)))
 384                return -EFAULT;
 385        return 0;
 386}
 387
 388#ifdef CONFIG_COMPAT
 389struct compat_hd_geometry {
 390        unsigned char heads;
 391        unsigned char sectors;
 392        unsigned short cylinders;
 393        u32 start;
 394};
 395
 396static int compat_hdio_getgeo(struct block_device *bdev,
 397                              struct compat_hd_geometry __user *ugeo)
 398{
 399        struct gendisk *disk = bdev->bd_disk;
 400        struct hd_geometry geo;
 401        int ret;
 402
 403        if (!ugeo)
 404                return -EINVAL;
 405        if (!disk->fops->getgeo)
 406                return -ENOTTY;
 407
 408        memset(&geo, 0, sizeof(geo));
 409        /*
 410         * We need to set the startsect first, the driver may
 411         * want to override it.
 412         */
 413        geo.start = get_start_sect(bdev);
 414        ret = disk->fops->getgeo(bdev, &geo);
 415        if (ret)
 416                return ret;
 417
 418        ret = copy_to_user(ugeo, &geo, 4);
 419        ret |= put_user(geo.start, &ugeo->start);
 420        if (ret)
 421                ret = -EFAULT;
 422
 423        return ret;
 424}
 425#endif
 426
 427/* set the logical block size */
 428static int blkdev_bszset(struct block_device *bdev, fmode_t mode,
 429                int __user *argp)
 430{
 431        int ret, n;
 432
 433        if (!capable(CAP_SYS_ADMIN))
 434                return -EACCES;
 435        if (!argp)
 436                return -EINVAL;
 437        if (get_user(n, argp))
 438                return -EFAULT;
 439
 440        if (mode & FMODE_EXCL)
 441                return set_blocksize(bdev, n);
 442
 443        if (IS_ERR(blkdev_get_by_dev(bdev->bd_dev, mode | FMODE_EXCL, &bdev)))
 444                return -EBUSY;
 445        ret = set_blocksize(bdev, n);
 446        blkdev_put(bdev, mode | FMODE_EXCL);
 447
 448        return ret;
 449}
 450
 451/*
 452 * Common commands that are handled the same way on native and compat
 453 * user space. Note the separate arg/argp parameters that are needed
 454 * to deal with the compat_ptr() conversion.
 455 */
 456static int blkdev_common_ioctl(struct block_device *bdev, fmode_t mode,
 457                                unsigned cmd, unsigned long arg, void __user *argp)
 458{
 459        unsigned int max_sectors;
 460
 461        switch (cmd) {
 462        case BLKFLSBUF:
 463                return blkdev_flushbuf(bdev, mode, cmd, arg);
 464        case BLKROSET:
 465                return blkdev_roset(bdev, mode, cmd, arg);
 466        case BLKDISCARD:
 467                return blk_ioctl_discard(bdev, mode, arg, 0);
 468        case BLKSECDISCARD:
 469                return blk_ioctl_discard(bdev, mode, arg,
 470                                BLKDEV_DISCARD_SECURE);
 471        case BLKZEROOUT:
 472                return blk_ioctl_zeroout(bdev, mode, arg);
 473        case BLKGETDISKSEQ:
 474                return put_u64(argp, bdev->bd_disk->diskseq);
 475        case BLKREPORTZONE:
 476                return blkdev_report_zones_ioctl(bdev, mode, cmd, arg);
 477        case BLKRESETZONE:
 478        case BLKOPENZONE:
 479        case BLKCLOSEZONE:
 480        case BLKFINISHZONE:
 481                return blkdev_zone_mgmt_ioctl(bdev, mode, cmd, arg);
 482        case BLKGETZONESZ:
 483                return put_uint(argp, bdev_zone_sectors(bdev));
 484        case BLKGETNRZONES:
 485                return put_uint(argp, blkdev_nr_zones(bdev->bd_disk));
 486        case BLKROGET:
 487                return put_int(argp, bdev_read_only(bdev) != 0);
 488        case BLKSSZGET: /* get block device logical block size */
 489                return put_int(argp, bdev_logical_block_size(bdev));
 490        case BLKPBSZGET: /* get block device physical block size */
 491                return put_uint(argp, bdev_physical_block_size(bdev));
 492        case BLKIOMIN:
 493                return put_uint(argp, bdev_io_min(bdev));
 494        case BLKIOOPT:
 495                return put_uint(argp, bdev_io_opt(bdev));
 496        case BLKALIGNOFF:
 497                return put_int(argp, bdev_alignment_offset(bdev));
 498        case BLKDISCARDZEROES:
 499                return put_uint(argp, 0);
 500        case BLKSECTGET:
 501                max_sectors = min_t(unsigned int, USHRT_MAX,
 502                                    queue_max_sectors(bdev_get_queue(bdev)));
 503                return put_ushort(argp, max_sectors);
 504        case BLKROTATIONAL:
 505                return put_ushort(argp, !blk_queue_nonrot(bdev_get_queue(bdev)));
 506        case BLKRASET:
 507        case BLKFRASET:
 508                if(!capable(CAP_SYS_ADMIN))
 509                        return -EACCES;
 510                bdev->bd_disk->bdi->ra_pages = (arg * 512) / PAGE_SIZE;
 511                return 0;
 512        case BLKRRPART:
 513                return blkdev_reread_part(bdev, mode);
 514        case BLKTRACESTART:
 515        case BLKTRACESTOP:
 516        case BLKTRACETEARDOWN:
 517                return blk_trace_ioctl(bdev, cmd, argp);
 518        case IOC_PR_REGISTER:
 519                return blkdev_pr_register(bdev, argp);
 520        case IOC_PR_RESERVE:
 521                return blkdev_pr_reserve(bdev, argp);
 522        case IOC_PR_RELEASE:
 523                return blkdev_pr_release(bdev, argp);
 524        case IOC_PR_PREEMPT:
 525                return blkdev_pr_preempt(bdev, argp, false);
 526        case IOC_PR_PREEMPT_ABORT:
 527                return blkdev_pr_preempt(bdev, argp, true);
 528        case IOC_PR_CLEAR:
 529                return blkdev_pr_clear(bdev, argp);
 530        default:
 531                return -ENOIOCTLCMD;
 532        }
 533}
 534
 535/*
 536 * Always keep this in sync with compat_blkdev_ioctl()
 537 * to handle all incompatible commands in both functions.
 538 *
 539 * New commands must be compatible and go into blkdev_common_ioctl
 540 */
 541int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
 542                        unsigned long arg)
 543{
 544        int ret;
 545        loff_t size;
 546        void __user *argp = (void __user *)arg;
 547
 548        switch (cmd) {
 549        /* These need separate implementations for the data structure */
 550        case HDIO_GETGEO:
 551                return blkdev_getgeo(bdev, argp);
 552        case BLKPG:
 553                return blkpg_ioctl(bdev, argp);
 554
 555        /* Compat mode returns 32-bit data instead of 'long' */
 556        case BLKRAGET:
 557        case BLKFRAGET:
 558                if (!argp)
 559                        return -EINVAL;
 560                return put_long(argp,
 561                        (bdev->bd_disk->bdi->ra_pages * PAGE_SIZE) / 512);
 562        case BLKGETSIZE:
 563                size = i_size_read(bdev->bd_inode);
 564                if ((size >> 9) > ~0UL)
 565                        return -EFBIG;
 566                return put_ulong(argp, size >> 9);
 567
 568        /* The data is compatible, but the command number is different */
 569        case BLKBSZGET: /* get block device soft block size (cf. BLKSSZGET) */
 570                return put_int(argp, block_size(bdev));
 571        case BLKBSZSET:
 572                return blkdev_bszset(bdev, mode, argp);
 573        case BLKGETSIZE64:
 574                return put_u64(argp, i_size_read(bdev->bd_inode));
 575
 576        /* Incompatible alignment on i386 */
 577        case BLKTRACESETUP:
 578                return blk_trace_ioctl(bdev, cmd, argp);
 579        default:
 580                break;
 581        }
 582
 583        ret = blkdev_common_ioctl(bdev, mode, cmd, arg, argp);
 584        if (ret != -ENOIOCTLCMD)
 585                return ret;
 586
 587        if (!bdev->bd_disk->fops->ioctl)
 588                return -ENOTTY;
 589        return bdev->bd_disk->fops->ioctl(bdev, mode, cmd, arg);
 590}
 591EXPORT_SYMBOL_GPL(blkdev_ioctl); /* for /dev/raw */
 592
 593#ifdef CONFIG_COMPAT
 594
 595#define BLKBSZGET_32            _IOR(0x12, 112, int)
 596#define BLKBSZSET_32            _IOW(0x12, 113, int)
 597#define BLKGETSIZE64_32         _IOR(0x12, 114, int)
 598
 599/* Most of the generic ioctls are handled in the normal fallback path.
 600   This assumes the blkdev's low level compat_ioctl always returns
 601   ENOIOCTLCMD for unknown ioctls. */
 602long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 603{
 604        int ret;
 605        void __user *argp = compat_ptr(arg);
 606        struct block_device *bdev = I_BDEV(file->f_mapping->host);
 607        struct gendisk *disk = bdev->bd_disk;
 608        fmode_t mode = file->f_mode;
 609        loff_t size;
 610
 611        /*
 612         * O_NDELAY can be altered using fcntl(.., F_SETFL, ..), so we have
 613         * to updated it before every ioctl.
 614         */
 615        if (file->f_flags & O_NDELAY)
 616                mode |= FMODE_NDELAY;
 617        else
 618                mode &= ~FMODE_NDELAY;
 619
 620        switch (cmd) {
 621        /* These need separate implementations for the data structure */
 622        case HDIO_GETGEO:
 623                return compat_hdio_getgeo(bdev, argp);
 624        case BLKPG:
 625                return compat_blkpg_ioctl(bdev, argp);
 626
 627        /* Compat mode returns 32-bit data instead of 'long' */
 628        case BLKRAGET:
 629        case BLKFRAGET:
 630                if (!argp)
 631                        return -EINVAL;
 632                return compat_put_long(argp,
 633                        (bdev->bd_disk->bdi->ra_pages * PAGE_SIZE) / 512);
 634        case BLKGETSIZE:
 635                size = i_size_read(bdev->bd_inode);
 636                if ((size >> 9) > ~0UL)
 637                        return -EFBIG;
 638                return compat_put_ulong(argp, size >> 9);
 639
 640        /* The data is compatible, but the command number is different */
 641        case BLKBSZGET_32: /* get the logical block size (cf. BLKSSZGET) */
 642                return put_int(argp, bdev_logical_block_size(bdev));
 643        case BLKBSZSET_32:
 644                return blkdev_bszset(bdev, mode, argp);
 645        case BLKGETSIZE64_32:
 646                return put_u64(argp, i_size_read(bdev->bd_inode));
 647
 648        /* Incompatible alignment on i386 */
 649        case BLKTRACESETUP32:
 650                return blk_trace_ioctl(bdev, cmd, argp);
 651        default:
 652                break;
 653        }
 654
 655        ret = blkdev_common_ioctl(bdev, mode, cmd, arg, argp);
 656        if (ret == -ENOIOCTLCMD && disk->fops->compat_ioctl)
 657                ret = disk->fops->compat_ioctl(bdev, mode, cmd, arg);
 658
 659        return ret;
 660}
 661#endif
 662