xref: /linux/block/ioctl.c (revision 4eb7ae7a301d3586c3351e81d5c3cfe2304a1a6a)
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 
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 static int blkdev_reread_part(struct block_device *bdev)
159 {
160 	int ret;
161 
162 	if (!disk_part_scan_enabled(bdev->bd_disk) || bdev != bdev->bd_contains)
163 		return -EINVAL;
164 	if (!capable(CAP_SYS_ADMIN))
165 		return -EACCES;
166 
167 	mutex_lock(&bdev->bd_mutex);
168 	ret = bdev_disk_changed(bdev, false);
169 	mutex_unlock(&bdev->bd_mutex);
170 
171 	return ret;
172 }
173 
174 static int blk_ioctl_discard(struct block_device *bdev, fmode_t mode,
175 		unsigned long arg, unsigned long flags)
176 {
177 	uint64_t range[2];
178 	uint64_t start, len;
179 	struct request_queue *q = bdev_get_queue(bdev);
180 	struct address_space *mapping = bdev->bd_inode->i_mapping;
181 
182 
183 	if (!(mode & FMODE_WRITE))
184 		return -EBADF;
185 
186 	if (!blk_queue_discard(q))
187 		return -EOPNOTSUPP;
188 
189 	if (copy_from_user(range, (void __user *)arg, sizeof(range)))
190 		return -EFAULT;
191 
192 	start = range[0];
193 	len = range[1];
194 
195 	if (start & 511)
196 		return -EINVAL;
197 	if (len & 511)
198 		return -EINVAL;
199 
200 	if (start + len > i_size_read(bdev->bd_inode))
201 		return -EINVAL;
202 	truncate_inode_pages_range(mapping, start, start + len - 1);
203 	return blkdev_issue_discard(bdev, start >> 9, len >> 9,
204 				    GFP_KERNEL, flags);
205 }
206 
207 static int blk_ioctl_zeroout(struct block_device *bdev, fmode_t mode,
208 		unsigned long arg)
209 {
210 	uint64_t range[2];
211 	struct address_space *mapping;
212 	uint64_t start, end, len;
213 
214 	if (!(mode & FMODE_WRITE))
215 		return -EBADF;
216 
217 	if (copy_from_user(range, (void __user *)arg, sizeof(range)))
218 		return -EFAULT;
219 
220 	start = range[0];
221 	len = range[1];
222 	end = start + len - 1;
223 
224 	if (start & 511)
225 		return -EINVAL;
226 	if (len & 511)
227 		return -EINVAL;
228 	if (end >= (uint64_t)i_size_read(bdev->bd_inode))
229 		return -EINVAL;
230 	if (end < start)
231 		return -EINVAL;
232 
233 	/* Invalidate the page cache, including dirty pages */
234 	mapping = bdev->bd_inode->i_mapping;
235 	truncate_inode_pages_range(mapping, start, end);
236 
237 	return blkdev_issue_zeroout(bdev, start >> 9, len >> 9, GFP_KERNEL,
238 			BLKDEV_ZERO_NOUNMAP);
239 }
240 
241 static int put_ushort(unsigned long arg, unsigned short val)
242 {
243 	return put_user(val, (unsigned short __user *)arg);
244 }
245 
246 static int put_int(unsigned long arg, int val)
247 {
248 	return put_user(val, (int __user *)arg);
249 }
250 
251 static int put_uint(unsigned long arg, unsigned int val)
252 {
253 	return put_user(val, (unsigned int __user *)arg);
254 }
255 
256 static int put_long(unsigned long arg, long val)
257 {
258 	return put_user(val, (long __user *)arg);
259 }
260 
261 static int put_ulong(unsigned long arg, unsigned long val)
262 {
263 	return put_user(val, (unsigned long __user *)arg);
264 }
265 
266 static int put_u64(unsigned long arg, u64 val)
267 {
268 	return put_user(val, (u64 __user *)arg);
269 }
270 
271 int __blkdev_driver_ioctl(struct block_device *bdev, fmode_t mode,
272 			unsigned cmd, unsigned long arg)
273 {
274 	struct gendisk *disk = bdev->bd_disk;
275 
276 	if (disk->fops->ioctl)
277 		return disk->fops->ioctl(bdev, mode, cmd, arg);
278 
279 	return -ENOTTY;
280 }
281 /*
282  * For the record: _GPL here is only because somebody decided to slap it
283  * on the previous export.  Sheer idiocy, since it wasn't copyrightable
284  * at all and could be open-coded without any exports by anybody who cares.
285  */
286 EXPORT_SYMBOL_GPL(__blkdev_driver_ioctl);
287 
288 static int blkdev_pr_register(struct block_device *bdev,
289 		struct pr_registration __user *arg)
290 {
291 	const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
292 	struct pr_registration reg;
293 
294 	if (!capable(CAP_SYS_ADMIN))
295 		return -EPERM;
296 	if (!ops || !ops->pr_register)
297 		return -EOPNOTSUPP;
298 	if (copy_from_user(&reg, arg, sizeof(reg)))
299 		return -EFAULT;
300 
301 	if (reg.flags & ~PR_FL_IGNORE_KEY)
302 		return -EOPNOTSUPP;
303 	return ops->pr_register(bdev, reg.old_key, reg.new_key, reg.flags);
304 }
305 
306 static int blkdev_pr_reserve(struct block_device *bdev,
307 		struct pr_reservation __user *arg)
308 {
309 	const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
310 	struct pr_reservation rsv;
311 
312 	if (!capable(CAP_SYS_ADMIN))
313 		return -EPERM;
314 	if (!ops || !ops->pr_reserve)
315 		return -EOPNOTSUPP;
316 	if (copy_from_user(&rsv, arg, sizeof(rsv)))
317 		return -EFAULT;
318 
319 	if (rsv.flags & ~PR_FL_IGNORE_KEY)
320 		return -EOPNOTSUPP;
321 	return ops->pr_reserve(bdev, rsv.key, rsv.type, rsv.flags);
322 }
323 
324 static int blkdev_pr_release(struct block_device *bdev,
325 		struct pr_reservation __user *arg)
326 {
327 	const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
328 	struct pr_reservation rsv;
329 
330 	if (!capable(CAP_SYS_ADMIN))
331 		return -EPERM;
332 	if (!ops || !ops->pr_release)
333 		return -EOPNOTSUPP;
334 	if (copy_from_user(&rsv, arg, sizeof(rsv)))
335 		return -EFAULT;
336 
337 	if (rsv.flags)
338 		return -EOPNOTSUPP;
339 	return ops->pr_release(bdev, rsv.key, rsv.type);
340 }
341 
342 static int blkdev_pr_preempt(struct block_device *bdev,
343 		struct pr_preempt __user *arg, bool abort)
344 {
345 	const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
346 	struct pr_preempt p;
347 
348 	if (!capable(CAP_SYS_ADMIN))
349 		return -EPERM;
350 	if (!ops || !ops->pr_preempt)
351 		return -EOPNOTSUPP;
352 	if (copy_from_user(&p, arg, sizeof(p)))
353 		return -EFAULT;
354 
355 	if (p.flags)
356 		return -EOPNOTSUPP;
357 	return ops->pr_preempt(bdev, p.old_key, p.new_key, p.type, abort);
358 }
359 
360 static int blkdev_pr_clear(struct block_device *bdev,
361 		struct pr_clear __user *arg)
362 {
363 	const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
364 	struct pr_clear c;
365 
366 	if (!capable(CAP_SYS_ADMIN))
367 		return -EPERM;
368 	if (!ops || !ops->pr_clear)
369 		return -EOPNOTSUPP;
370 	if (copy_from_user(&c, arg, sizeof(c)))
371 		return -EFAULT;
372 
373 	if (c.flags)
374 		return -EOPNOTSUPP;
375 	return ops->pr_clear(bdev, c.key);
376 }
377 
378 /*
379  * Is it an unrecognized ioctl? The correct returns are either
380  * ENOTTY (final) or ENOIOCTLCMD ("I don't know this one, try a
381  * fallback"). ENOIOCTLCMD gets turned into ENOTTY by the ioctl
382  * code before returning.
383  *
384  * Confused drivers sometimes return EINVAL, which is wrong. It
385  * means "I understood the ioctl command, but the parameters to
386  * it were wrong".
387  *
388  * We should aim to just fix the broken drivers, the EINVAL case
389  * should go away.
390  */
391 static inline int is_unrecognized_ioctl(int ret)
392 {
393 	return	ret == -EINVAL ||
394 		ret == -ENOTTY ||
395 		ret == -ENOIOCTLCMD;
396 }
397 
398 static int blkdev_flushbuf(struct block_device *bdev, fmode_t mode,
399 		unsigned cmd, unsigned long arg)
400 {
401 	int ret;
402 
403 	if (!capable(CAP_SYS_ADMIN))
404 		return -EACCES;
405 
406 	ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
407 	if (!is_unrecognized_ioctl(ret))
408 		return ret;
409 
410 	fsync_bdev(bdev);
411 	invalidate_bdev(bdev);
412 	return 0;
413 }
414 
415 static int blkdev_roset(struct block_device *bdev, fmode_t mode,
416 		unsigned cmd, unsigned long arg)
417 {
418 	int ret, n;
419 
420 	if (!capable(CAP_SYS_ADMIN))
421 		return -EACCES;
422 
423 	ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
424 	if (!is_unrecognized_ioctl(ret))
425 		return ret;
426 	if (get_user(n, (int __user *)arg))
427 		return -EFAULT;
428 	set_device_ro(bdev, n);
429 	return 0;
430 }
431 
432 static int blkdev_getgeo(struct block_device *bdev,
433 		struct hd_geometry __user *argp)
434 {
435 	struct gendisk *disk = bdev->bd_disk;
436 	struct hd_geometry geo;
437 	int ret;
438 
439 	if (!argp)
440 		return -EINVAL;
441 	if (!disk->fops->getgeo)
442 		return -ENOTTY;
443 
444 	/*
445 	 * We need to set the startsect first, the driver may
446 	 * want to override it.
447 	 */
448 	memset(&geo, 0, sizeof(geo));
449 	geo.start = get_start_sect(bdev);
450 	ret = disk->fops->getgeo(bdev, &geo);
451 	if (ret)
452 		return ret;
453 	if (copy_to_user(argp, &geo, sizeof(geo)))
454 		return -EFAULT;
455 	return 0;
456 }
457 
458 /* set the logical block size */
459 static int blkdev_bszset(struct block_device *bdev, fmode_t mode,
460 		int __user *argp)
461 {
462 	int ret, n;
463 
464 	if (!capable(CAP_SYS_ADMIN))
465 		return -EACCES;
466 	if (!argp)
467 		return -EINVAL;
468 	if (get_user(n, argp))
469 		return -EFAULT;
470 
471 	if (!(mode & FMODE_EXCL)) {
472 		bdgrab(bdev);
473 		if (blkdev_get(bdev, mode | FMODE_EXCL, &bdev) < 0)
474 			return -EBUSY;
475 	}
476 
477 	ret = set_blocksize(bdev, n);
478 	if (!(mode & FMODE_EXCL))
479 		blkdev_put(bdev, mode | FMODE_EXCL);
480 	return ret;
481 }
482 
483 /*
484  * always keep this in sync with compat_blkdev_ioctl()
485  */
486 int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
487 			unsigned long arg)
488 {
489 	void __user *argp = (void __user *)arg;
490 	loff_t size;
491 	unsigned int max_sectors;
492 
493 	switch (cmd) {
494 	case BLKFLSBUF:
495 		return blkdev_flushbuf(bdev, mode, cmd, arg);
496 	case BLKROSET:
497 		return blkdev_roset(bdev, mode, cmd, arg);
498 	case BLKDISCARD:
499 		return blk_ioctl_discard(bdev, mode, arg, 0);
500 	case BLKSECDISCARD:
501 		return blk_ioctl_discard(bdev, mode, arg,
502 				BLKDEV_DISCARD_SECURE);
503 	case BLKZEROOUT:
504 		return blk_ioctl_zeroout(bdev, mode, arg);
505 	case BLKREPORTZONE:
506 		return blkdev_report_zones_ioctl(bdev, mode, cmd, arg);
507 	case BLKRESETZONE:
508 	case BLKOPENZONE:
509 	case BLKCLOSEZONE:
510 	case BLKFINISHZONE:
511 		return blkdev_zone_mgmt_ioctl(bdev, mode, cmd, arg);
512 	case BLKGETZONESZ:
513 		return put_uint(arg, bdev_zone_sectors(bdev));
514 	case BLKGETNRZONES:
515 		return put_uint(arg, blkdev_nr_zones(bdev->bd_disk));
516 	case HDIO_GETGEO:
517 		return blkdev_getgeo(bdev, argp);
518 	case BLKRAGET:
519 	case BLKFRAGET:
520 		if (!arg)
521 			return -EINVAL;
522 		return put_long(arg, (bdev->bd_bdi->ra_pages*PAGE_SIZE) / 512);
523 	case BLKROGET:
524 		return put_int(arg, bdev_read_only(bdev) != 0);
525 	case BLKBSZGET: /* get block device soft block size (cf. BLKSSZGET) */
526 		return put_int(arg, block_size(bdev));
527 	case BLKSSZGET: /* get block device logical block size */
528 		return put_int(arg, bdev_logical_block_size(bdev));
529 	case BLKPBSZGET: /* get block device physical block size */
530 		return put_uint(arg, bdev_physical_block_size(bdev));
531 	case BLKIOMIN:
532 		return put_uint(arg, bdev_io_min(bdev));
533 	case BLKIOOPT:
534 		return put_uint(arg, bdev_io_opt(bdev));
535 	case BLKALIGNOFF:
536 		return put_int(arg, bdev_alignment_offset(bdev));
537 	case BLKDISCARDZEROES:
538 		return put_uint(arg, 0);
539 	case BLKSECTGET:
540 		max_sectors = min_t(unsigned int, USHRT_MAX,
541 				    queue_max_sectors(bdev_get_queue(bdev)));
542 		return put_ushort(arg, max_sectors);
543 	case BLKROTATIONAL:
544 		return put_ushort(arg, !blk_queue_nonrot(bdev_get_queue(bdev)));
545 	case BLKRASET:
546 	case BLKFRASET:
547 		if(!capable(CAP_SYS_ADMIN))
548 			return -EACCES;
549 		bdev->bd_bdi->ra_pages = (arg * 512) / PAGE_SIZE;
550 		return 0;
551 	case BLKBSZSET:
552 		return blkdev_bszset(bdev, mode, argp);
553 	case BLKPG:
554 		return blkpg_ioctl(bdev, argp);
555 	case BLKRRPART:
556 		return blkdev_reread_part(bdev);
557 	case BLKGETSIZE:
558 		size = i_size_read(bdev->bd_inode);
559 		if ((size >> 9) > ~0UL)
560 			return -EFBIG;
561 		return put_ulong(arg, size >> 9);
562 	case BLKGETSIZE64:
563 		return put_u64(arg, i_size_read(bdev->bd_inode));
564 	case BLKTRACESTART:
565 	case BLKTRACESTOP:
566 	case BLKTRACESETUP:
567 	case BLKTRACETEARDOWN:
568 		return blk_trace_ioctl(bdev, cmd, argp);
569 	case IOC_PR_REGISTER:
570 		return blkdev_pr_register(bdev, argp);
571 	case IOC_PR_RESERVE:
572 		return blkdev_pr_reserve(bdev, argp);
573 	case IOC_PR_RELEASE:
574 		return blkdev_pr_release(bdev, argp);
575 	case IOC_PR_PREEMPT:
576 		return blkdev_pr_preempt(bdev, argp, false);
577 	case IOC_PR_PREEMPT_ABORT:
578 		return blkdev_pr_preempt(bdev, argp, true);
579 	case IOC_PR_CLEAR:
580 		return blkdev_pr_clear(bdev, argp);
581 	default:
582 		return __blkdev_driver_ioctl(bdev, mode, cmd, arg);
583 	}
584 }
585 EXPORT_SYMBOL_GPL(blkdev_ioctl);
586