1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/capability.h>
3 #include <linux/blkdev.h>
4 #include <linux/export.h>
5 #include <linux/gfp.h>
6 #include <linux/blkpg.h>
7 #include <linux/hdreg.h>
8 #include <linux/backing-dev.h>
9 #include <linux/fs.h>
10 #include <linux/blktrace_api.h>
11 #include <linux/pr.h>
12 #include <linux/uaccess.h>
13
blkpg_ioctl(struct block_device * bdev,struct blkpg_ioctl_arg __user * arg)14 static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user *arg)
15 {
16 struct block_device *bdevp;
17 struct gendisk *disk;
18 struct hd_struct *part, *lpart;
19 struct blkpg_ioctl_arg a;
20 struct blkpg_partition p;
21 struct disk_part_iter piter;
22 long long start, length;
23 int partno;
24
25 if (!capable(CAP_SYS_ADMIN))
26 return -EACCES;
27 if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
28 return -EFAULT;
29 if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
30 return -EFAULT;
31 disk = bdev->bd_disk;
32 if (bdev != bdev->bd_contains)
33 return -EINVAL;
34 partno = p.pno;
35 if (partno <= 0)
36 return -EINVAL;
37 switch (a.op) {
38 case BLKPG_ADD_PARTITION:
39 start = p.start >> 9;
40 length = p.length >> 9;
41 /* check for fit in a hd_struct */
42 if (sizeof(sector_t) == sizeof(long) &&
43 sizeof(long long) > sizeof(long)) {
44 long pstart = start, plength = length;
45 if (pstart != start || plength != length
46 || pstart < 0 || plength < 0 || partno > 65535)
47 return -EINVAL;
48 }
49 /* check if partition is aligned to blocksize */
50 if (p.start & (bdev_logical_block_size(bdev) - 1))
51 return -EINVAL;
52
53 mutex_lock(&bdev->bd_mutex);
54
55 /* overlap? */
56 disk_part_iter_init(&piter, disk,
57 DISK_PITER_INCL_EMPTY);
58 while ((part = disk_part_iter_next(&piter))) {
59 if (!(start + length <= part->start_sect ||
60 start >= part->start_sect + part->nr_sects)) {
61 disk_part_iter_exit(&piter);
62 mutex_unlock(&bdev->bd_mutex);
63 return -EBUSY;
64 }
65 }
66 disk_part_iter_exit(&piter);
67
68 /* all seems OK */
69 part = add_partition(disk, partno, start, length,
70 ADDPART_FLAG_NONE, NULL);
71 mutex_unlock(&bdev->bd_mutex);
72 return PTR_ERR_OR_ZERO(part);
73 case BLKPG_DEL_PARTITION:
74 part = disk_get_part(disk, partno);
75 if (!part)
76 return -ENXIO;
77
78 bdevp = bdget(part_devt(part));
79 disk_put_part(part);
80 if (!bdevp)
81 return -ENOMEM;
82
83 mutex_lock(&bdevp->bd_mutex);
84 if (bdevp->bd_openers) {
85 mutex_unlock(&bdevp->bd_mutex);
86 bdput(bdevp);
87 return -EBUSY;
88 }
89 /* all seems OK */
90 fsync_bdev(bdevp);
91 invalidate_bdev(bdevp);
92
93 mutex_lock_nested(&bdev->bd_mutex, 1);
94 delete_partition(disk, partno);
95 mutex_unlock(&bdev->bd_mutex);
96 mutex_unlock(&bdevp->bd_mutex);
97 bdput(bdevp);
98
99 return 0;
100 case BLKPG_RESIZE_PARTITION:
101 start = p.start >> 9;
102 /* new length of partition in bytes */
103 length = p.length >> 9;
104 /* check for fit in a hd_struct */
105 if (sizeof(sector_t) == sizeof(long) &&
106 sizeof(long long) > sizeof(long)) {
107 long pstart = start, plength = length;
108 if (pstart != start || plength != length
109 || pstart < 0 || plength < 0)
110 return -EINVAL;
111 }
112 part = disk_get_part(disk, partno);
113 if (!part)
114 return -ENXIO;
115 bdevp = bdget(part_devt(part));
116 if (!bdevp) {
117 disk_put_part(part);
118 return -ENOMEM;
119 }
120 mutex_lock(&bdevp->bd_mutex);
121 mutex_lock_nested(&bdev->bd_mutex, 1);
122 if (start != part->start_sect) {
123 mutex_unlock(&bdevp->bd_mutex);
124 mutex_unlock(&bdev->bd_mutex);
125 bdput(bdevp);
126 disk_put_part(part);
127 return -EINVAL;
128 }
129 /* overlap? */
130 disk_part_iter_init(&piter, disk,
131 DISK_PITER_INCL_EMPTY);
132 while ((lpart = disk_part_iter_next(&piter))) {
133 if (lpart->partno != partno &&
134 !(start + length <= lpart->start_sect ||
135 start >= lpart->start_sect + lpart->nr_sects)
136 ) {
137 disk_part_iter_exit(&piter);
138 mutex_unlock(&bdevp->bd_mutex);
139 mutex_unlock(&bdev->bd_mutex);
140 bdput(bdevp);
141 disk_put_part(part);
142 return -EBUSY;
143 }
144 }
145 disk_part_iter_exit(&piter);
146 part_nr_sects_write(part, (sector_t)length);
147 i_size_write(bdevp->bd_inode, p.length);
148 mutex_unlock(&bdevp->bd_mutex);
149 mutex_unlock(&bdev->bd_mutex);
150 bdput(bdevp);
151 disk_put_part(part);
152 return 0;
153 default:
154 return -EINVAL;
155 }
156 }
157
158 /*
159 * This is an exported API for the block driver, and will not
160 * acquire bd_mutex. This API should be used in case that
161 * caller has held bd_mutex already.
162 */
__blkdev_reread_part(struct block_device * bdev)163 int __blkdev_reread_part(struct block_device *bdev)
164 {
165 struct gendisk *disk = bdev->bd_disk;
166
167 if (!disk_part_scan_enabled(disk) || bdev != bdev->bd_contains)
168 return -EINVAL;
169 if (!capable(CAP_SYS_ADMIN))
170 return -EACCES;
171
172 lockdep_assert_held(&bdev->bd_mutex);
173
174 return rescan_partitions(disk, bdev);
175 }
176 EXPORT_SYMBOL(__blkdev_reread_part);
177
178 /*
179 * This is an exported API for the block driver, and will
180 * try to acquire bd_mutex. If bd_mutex has been held already
181 * in current context, please call __blkdev_reread_part().
182 *
183 * Make sure the held locks in current context aren't required
184 * in open()/close() handler and I/O path for avoiding ABBA deadlock:
185 * - bd_mutex is held before calling block driver's open/close
186 * handler
187 * - reading partition table may submit I/O to the block device
188 */
blkdev_reread_part(struct block_device * bdev)189 int blkdev_reread_part(struct block_device *bdev)
190 {
191 int res;
192
193 mutex_lock(&bdev->bd_mutex);
194 res = __blkdev_reread_part(bdev);
195 mutex_unlock(&bdev->bd_mutex);
196
197 return res;
198 }
199 EXPORT_SYMBOL(blkdev_reread_part);
200
blk_ioctl_discard(struct block_device * bdev,fmode_t mode,unsigned long arg,unsigned long flags)201 static int blk_ioctl_discard(struct block_device *bdev, fmode_t mode,
202 unsigned long arg, unsigned long flags)
203 {
204 uint64_t range[2];
205 uint64_t start, len;
206 struct request_queue *q = bdev_get_queue(bdev);
207 struct address_space *mapping = bdev->bd_inode->i_mapping;
208
209
210 if (!(mode & FMODE_WRITE))
211 return -EBADF;
212
213 if (!blk_queue_discard(q))
214 return -EOPNOTSUPP;
215
216 if (copy_from_user(range, (void __user *)arg, sizeof(range)))
217 return -EFAULT;
218
219 start = range[0];
220 len = range[1];
221
222 if (start & 511)
223 return -EINVAL;
224 if (len & 511)
225 return -EINVAL;
226
227 if (start + len > i_size_read(bdev->bd_inode))
228 return -EINVAL;
229 truncate_inode_pages_range(mapping, start, start + len - 1);
230 return blkdev_issue_discard(bdev, start >> 9, len >> 9,
231 GFP_KERNEL, flags);
232 }
233
blk_ioctl_zeroout(struct block_device * bdev,fmode_t mode,unsigned long arg)234 static int blk_ioctl_zeroout(struct block_device *bdev, fmode_t mode,
235 unsigned long arg)
236 {
237 uint64_t range[2];
238 struct address_space *mapping;
239 uint64_t start, end, len;
240
241 if (!(mode & FMODE_WRITE))
242 return -EBADF;
243
244 if (copy_from_user(range, (void __user *)arg, sizeof(range)))
245 return -EFAULT;
246
247 start = range[0];
248 len = range[1];
249 end = start + len - 1;
250
251 if (start & 511)
252 return -EINVAL;
253 if (len & 511)
254 return -EINVAL;
255 if (end >= (uint64_t)i_size_read(bdev->bd_inode))
256 return -EINVAL;
257 if (end < start)
258 return -EINVAL;
259
260 /* Invalidate the page cache, including dirty pages */
261 mapping = bdev->bd_inode->i_mapping;
262 truncate_inode_pages_range(mapping, start, end);
263
264 return blkdev_issue_zeroout(bdev, start >> 9, len >> 9, GFP_KERNEL,
265 BLKDEV_ZERO_NOUNMAP);
266 }
267
put_ushort(unsigned long arg,unsigned short val)268 static int put_ushort(unsigned long arg, unsigned short val)
269 {
270 return put_user(val, (unsigned short __user *)arg);
271 }
272
put_int(unsigned long arg,int val)273 static int put_int(unsigned long arg, int val)
274 {
275 return put_user(val, (int __user *)arg);
276 }
277
put_uint(unsigned long arg,unsigned int val)278 static int put_uint(unsigned long arg, unsigned int val)
279 {
280 return put_user(val, (unsigned int __user *)arg);
281 }
282
put_long(unsigned long arg,long val)283 static int put_long(unsigned long arg, long val)
284 {
285 return put_user(val, (long __user *)arg);
286 }
287
put_ulong(unsigned long arg,unsigned long val)288 static int put_ulong(unsigned long arg, unsigned long val)
289 {
290 return put_user(val, (unsigned long __user *)arg);
291 }
292
put_u64(unsigned long arg,u64 val)293 static int put_u64(unsigned long arg, u64 val)
294 {
295 return put_user(val, (u64 __user *)arg);
296 }
297
__blkdev_driver_ioctl(struct block_device * bdev,fmode_t mode,unsigned cmd,unsigned long arg)298 int __blkdev_driver_ioctl(struct block_device *bdev, fmode_t mode,
299 unsigned cmd, unsigned long arg)
300 {
301 struct gendisk *disk = bdev->bd_disk;
302
303 if (disk->fops->ioctl)
304 return disk->fops->ioctl(bdev, mode, cmd, arg);
305
306 return -ENOTTY;
307 }
308 /*
309 * For the record: _GPL here is only because somebody decided to slap it
310 * on the previous export. Sheer idiocy, since it wasn't copyrightable
311 * at all and could be open-coded without any exports by anybody who cares.
312 */
313 EXPORT_SYMBOL_GPL(__blkdev_driver_ioctl);
314
blkdev_pr_register(struct block_device * bdev,struct pr_registration __user * arg)315 static int blkdev_pr_register(struct block_device *bdev,
316 struct pr_registration __user *arg)
317 {
318 const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
319 struct pr_registration reg;
320
321 if (!capable(CAP_SYS_ADMIN))
322 return -EPERM;
323 if (!ops || !ops->pr_register)
324 return -EOPNOTSUPP;
325 if (copy_from_user(®, arg, sizeof(reg)))
326 return -EFAULT;
327
328 if (reg.flags & ~PR_FL_IGNORE_KEY)
329 return -EOPNOTSUPP;
330 return ops->pr_register(bdev, reg.old_key, reg.new_key, reg.flags);
331 }
332
blkdev_pr_reserve(struct block_device * bdev,struct pr_reservation __user * arg)333 static int blkdev_pr_reserve(struct block_device *bdev,
334 struct pr_reservation __user *arg)
335 {
336 const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
337 struct pr_reservation rsv;
338
339 if (!capable(CAP_SYS_ADMIN))
340 return -EPERM;
341 if (!ops || !ops->pr_reserve)
342 return -EOPNOTSUPP;
343 if (copy_from_user(&rsv, arg, sizeof(rsv)))
344 return -EFAULT;
345
346 if (rsv.flags & ~PR_FL_IGNORE_KEY)
347 return -EOPNOTSUPP;
348 return ops->pr_reserve(bdev, rsv.key, rsv.type, rsv.flags);
349 }
350
blkdev_pr_release(struct block_device * bdev,struct pr_reservation __user * arg)351 static int blkdev_pr_release(struct block_device *bdev,
352 struct pr_reservation __user *arg)
353 {
354 const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
355 struct pr_reservation rsv;
356
357 if (!capable(CAP_SYS_ADMIN))
358 return -EPERM;
359 if (!ops || !ops->pr_release)
360 return -EOPNOTSUPP;
361 if (copy_from_user(&rsv, arg, sizeof(rsv)))
362 return -EFAULT;
363
364 if (rsv.flags)
365 return -EOPNOTSUPP;
366 return ops->pr_release(bdev, rsv.key, rsv.type);
367 }
368
blkdev_pr_preempt(struct block_device * bdev,struct pr_preempt __user * arg,bool abort)369 static int blkdev_pr_preempt(struct block_device *bdev,
370 struct pr_preempt __user *arg, bool abort)
371 {
372 const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
373 struct pr_preempt p;
374
375 if (!capable(CAP_SYS_ADMIN))
376 return -EPERM;
377 if (!ops || !ops->pr_preempt)
378 return -EOPNOTSUPP;
379 if (copy_from_user(&p, arg, sizeof(p)))
380 return -EFAULT;
381
382 if (p.flags)
383 return -EOPNOTSUPP;
384 return ops->pr_preempt(bdev, p.old_key, p.new_key, p.type, abort);
385 }
386
blkdev_pr_clear(struct block_device * bdev,struct pr_clear __user * arg)387 static int blkdev_pr_clear(struct block_device *bdev,
388 struct pr_clear __user *arg)
389 {
390 const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
391 struct pr_clear c;
392
393 if (!capable(CAP_SYS_ADMIN))
394 return -EPERM;
395 if (!ops || !ops->pr_clear)
396 return -EOPNOTSUPP;
397 if (copy_from_user(&c, arg, sizeof(c)))
398 return -EFAULT;
399
400 if (c.flags)
401 return -EOPNOTSUPP;
402 return ops->pr_clear(bdev, c.key);
403 }
404
405 /*
406 * Is it an unrecognized ioctl? The correct returns are either
407 * ENOTTY (final) or ENOIOCTLCMD ("I don't know this one, try a
408 * fallback"). ENOIOCTLCMD gets turned into ENOTTY by the ioctl
409 * code before returning.
410 *
411 * Confused drivers sometimes return EINVAL, which is wrong. It
412 * means "I understood the ioctl command, but the parameters to
413 * it were wrong".
414 *
415 * We should aim to just fix the broken drivers, the EINVAL case
416 * should go away.
417 */
is_unrecognized_ioctl(int ret)418 static inline int is_unrecognized_ioctl(int ret)
419 {
420 return ret == -EINVAL ||
421 ret == -ENOTTY ||
422 ret == -ENOIOCTLCMD;
423 }
424
blkdev_flushbuf(struct block_device * bdev,fmode_t mode,unsigned cmd,unsigned long arg)425 static int blkdev_flushbuf(struct block_device *bdev, fmode_t mode,
426 unsigned cmd, unsigned long arg)
427 {
428 int ret;
429
430 if (!capable(CAP_SYS_ADMIN))
431 return -EACCES;
432
433 ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
434 if (!is_unrecognized_ioctl(ret))
435 return ret;
436
437 fsync_bdev(bdev);
438 invalidate_bdev(bdev);
439 return 0;
440 }
441
blkdev_roset(struct block_device * bdev,fmode_t mode,unsigned cmd,unsigned long arg)442 static int blkdev_roset(struct block_device *bdev, fmode_t mode,
443 unsigned cmd, unsigned long arg)
444 {
445 int ret, n;
446
447 if (!capable(CAP_SYS_ADMIN))
448 return -EACCES;
449
450 ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
451 if (!is_unrecognized_ioctl(ret))
452 return ret;
453 if (get_user(n, (int __user *)arg))
454 return -EFAULT;
455 set_device_ro(bdev, n);
456 return 0;
457 }
458
blkdev_getgeo(struct block_device * bdev,struct hd_geometry __user * argp)459 static int blkdev_getgeo(struct block_device *bdev,
460 struct hd_geometry __user *argp)
461 {
462 struct gendisk *disk = bdev->bd_disk;
463 struct hd_geometry geo;
464 int ret;
465
466 if (!argp)
467 return -EINVAL;
468 if (!disk->fops->getgeo)
469 return -ENOTTY;
470
471 /*
472 * We need to set the startsect first, the driver may
473 * want to override it.
474 */
475 memset(&geo, 0, sizeof(geo));
476 geo.start = get_start_sect(bdev);
477 ret = disk->fops->getgeo(bdev, &geo);
478 if (ret)
479 return ret;
480 if (copy_to_user(argp, &geo, sizeof(geo)))
481 return -EFAULT;
482 return 0;
483 }
484
485 /* set the logical block size */
blkdev_bszset(struct block_device * bdev,fmode_t mode,int __user * argp)486 static int blkdev_bszset(struct block_device *bdev, fmode_t mode,
487 int __user *argp)
488 {
489 int ret, n;
490
491 if (!capable(CAP_SYS_ADMIN))
492 return -EACCES;
493 if (!argp)
494 return -EINVAL;
495 if (get_user(n, argp))
496 return -EFAULT;
497
498 if (!(mode & FMODE_EXCL)) {
499 bdgrab(bdev);
500 if (blkdev_get(bdev, mode | FMODE_EXCL, &bdev) < 0)
501 return -EBUSY;
502 }
503
504 ret = set_blocksize(bdev, n);
505 if (!(mode & FMODE_EXCL))
506 blkdev_put(bdev, mode | FMODE_EXCL);
507 return ret;
508 }
509
510 /*
511 * always keep this in sync with compat_blkdev_ioctl()
512 */
blkdev_ioctl(struct block_device * bdev,fmode_t mode,unsigned cmd,unsigned long arg)513 int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
514 unsigned long arg)
515 {
516 void __user *argp = (void __user *)arg;
517 loff_t size;
518 unsigned int max_sectors;
519
520 switch (cmd) {
521 case BLKFLSBUF:
522 return blkdev_flushbuf(bdev, mode, cmd, arg);
523 case BLKROSET:
524 return blkdev_roset(bdev, mode, cmd, arg);
525 case BLKDISCARD:
526 return blk_ioctl_discard(bdev, mode, arg, 0);
527 case BLKSECDISCARD:
528 return blk_ioctl_discard(bdev, mode, arg,
529 BLKDEV_DISCARD_SECURE);
530 case BLKZEROOUT:
531 return blk_ioctl_zeroout(bdev, mode, arg);
532 case BLKREPORTZONE:
533 return blkdev_report_zones_ioctl(bdev, mode, cmd, arg);
534 case BLKRESETZONE:
535 return blkdev_reset_zones_ioctl(bdev, mode, cmd, arg);
536 case BLKGETZONESZ:
537 return put_uint(arg, bdev_zone_sectors(bdev));
538 case BLKGETNRZONES:
539 return put_uint(arg, blkdev_nr_zones(bdev));
540 case HDIO_GETGEO:
541 return blkdev_getgeo(bdev, argp);
542 case BLKRAGET:
543 case BLKFRAGET:
544 if (!arg)
545 return -EINVAL;
546 return put_long(arg, (bdev->bd_bdi->ra_pages*PAGE_SIZE) / 512);
547 case BLKROGET:
548 return put_int(arg, bdev_read_only(bdev) != 0);
549 case BLKBSZGET: /* get block device soft block size (cf. BLKSSZGET) */
550 return put_int(arg, block_size(bdev));
551 case BLKSSZGET: /* get block device logical block size */
552 return put_int(arg, bdev_logical_block_size(bdev));
553 case BLKPBSZGET: /* get block device physical block size */
554 return put_uint(arg, bdev_physical_block_size(bdev));
555 case BLKIOMIN:
556 return put_uint(arg, bdev_io_min(bdev));
557 case BLKIOOPT:
558 return put_uint(arg, bdev_io_opt(bdev));
559 case BLKALIGNOFF:
560 return put_int(arg, bdev_alignment_offset(bdev));
561 case BLKDISCARDZEROES:
562 return put_uint(arg, 0);
563 case BLKSECTGET:
564 max_sectors = min_t(unsigned int, USHRT_MAX,
565 queue_max_sectors(bdev_get_queue(bdev)));
566 return put_ushort(arg, max_sectors);
567 case BLKROTATIONAL:
568 return put_ushort(arg, !blk_queue_nonrot(bdev_get_queue(bdev)));
569 case BLKRASET:
570 case BLKFRASET:
571 if(!capable(CAP_SYS_ADMIN))
572 return -EACCES;
573 bdev->bd_bdi->ra_pages = (arg * 512) / PAGE_SIZE;
574 return 0;
575 case BLKBSZSET:
576 return blkdev_bszset(bdev, mode, argp);
577 case BLKPG:
578 return blkpg_ioctl(bdev, argp);
579 case BLKRRPART:
580 return blkdev_reread_part(bdev);
581 case BLKGETSIZE:
582 size = i_size_read(bdev->bd_inode);
583 if ((size >> 9) > ~0UL)
584 return -EFBIG;
585 return put_ulong(arg, size >> 9);
586 case BLKGETSIZE64:
587 return put_u64(arg, i_size_read(bdev->bd_inode));
588 case BLKTRACESTART:
589 case BLKTRACESTOP:
590 case BLKTRACESETUP:
591 case BLKTRACETEARDOWN:
592 return blk_trace_ioctl(bdev, cmd, argp);
593 case IOC_PR_REGISTER:
594 return blkdev_pr_register(bdev, argp);
595 case IOC_PR_RESERVE:
596 return blkdev_pr_reserve(bdev, argp);
597 case IOC_PR_RELEASE:
598 return blkdev_pr_release(bdev, argp);
599 case IOC_PR_PREEMPT:
600 return blkdev_pr_preempt(bdev, argp, false);
601 case IOC_PR_PREEMPT_ABORT:
602 return blkdev_pr_preempt(bdev, argp, true);
603 case IOC_PR_CLEAR:
604 return blkdev_pr_clear(bdev, argp);
605 default:
606 return __blkdev_driver_ioctl(bdev, mode, cmd, arg);
607 }
608 }
609 EXPORT_SYMBOL_GPL(blkdev_ioctl);
610
