xref: /linux/block/ioctl.c (revision 067012974c8ae31a8886046df082aeba93592972)
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 
16 static int blkpg_do_ioctl(struct block_device *bdev,
17 			  struct blkpg_partition __user *upart, int op)
18 {
19 	struct blkpg_partition p;
20 	long long start, length;
21 
22 	if (!capable(CAP_SYS_ADMIN))
23 		return -EACCES;
24 	if (copy_from_user(&p, upart, sizeof(struct blkpg_partition)))
25 		return -EFAULT;
26 	if (bdev_is_partition(bdev))
27 		return -EINVAL;
28 
29 	if (p.pno <= 0)
30 		return -EINVAL;
31 
32 	if (op == BLKPG_DEL_PARTITION)
33 		return bdev_del_partition(bdev, p.pno);
34 
35 	start = p.start >> SECTOR_SHIFT;
36 	length = p.length >> SECTOR_SHIFT;
37 
38 	switch (op) {
39 	case BLKPG_ADD_PARTITION:
40 		/* check if partition is aligned to blocksize */
41 		if (p.start & (bdev_logical_block_size(bdev) - 1))
42 			return -EINVAL;
43 		return bdev_add_partition(bdev, p.pno, start, length);
44 	case BLKPG_RESIZE_PARTITION:
45 		return bdev_resize_partition(bdev, p.pno, start, length);
46 	default:
47 		return -EINVAL;
48 	}
49 }
50 
51 static int blkpg_ioctl(struct block_device *bdev,
52 		       struct blkpg_ioctl_arg __user *arg)
53 {
54 	struct blkpg_partition __user *udata;
55 	int op;
56 
57 	if (get_user(op, &arg->op) || get_user(udata, &arg->data))
58 		return -EFAULT;
59 
60 	return blkpg_do_ioctl(bdev, udata, op);
61 }
62 
63 #ifdef CONFIG_COMPAT
64 struct compat_blkpg_ioctl_arg {
65 	compat_int_t op;
66 	compat_int_t flags;
67 	compat_int_t datalen;
68 	compat_caddr_t data;
69 };
70 
71 static int compat_blkpg_ioctl(struct block_device *bdev,
72 			      struct compat_blkpg_ioctl_arg __user *arg)
73 {
74 	compat_caddr_t udata;
75 	int op;
76 
77 	if (get_user(op, &arg->op) || get_user(udata, &arg->data))
78 		return -EFAULT;
79 
80 	return blkpg_do_ioctl(bdev, compat_ptr(udata), op);
81 }
82 #endif
83 
84 static int blkdev_reread_part(struct block_device *bdev)
85 {
86 	int ret;
87 
88 	if (!disk_part_scan_enabled(bdev->bd_disk) || bdev_is_partition(bdev))
89 		return -EINVAL;
90 	if (!capable(CAP_SYS_ADMIN))
91 		return -EACCES;
92 
93 	mutex_lock(&bdev->bd_mutex);
94 	ret = bdev_disk_changed(bdev, false);
95 	mutex_unlock(&bdev->bd_mutex);
96 
97 	return ret;
98 }
99 
100 static int blk_ioctl_discard(struct block_device *bdev, fmode_t mode,
101 		unsigned long arg, unsigned long flags)
102 {
103 	uint64_t range[2];
104 	uint64_t start, len;
105 	struct request_queue *q = bdev_get_queue(bdev);
106 	int err;
107 
108 	if (!(mode & FMODE_WRITE))
109 		return -EBADF;
110 
111 	if (!blk_queue_discard(q))
112 		return -EOPNOTSUPP;
113 
114 	if (copy_from_user(range, (void __user *)arg, sizeof(range)))
115 		return -EFAULT;
116 
117 	start = range[0];
118 	len = range[1];
119 
120 	if (start & 511)
121 		return -EINVAL;
122 	if (len & 511)
123 		return -EINVAL;
124 
125 	if (start + len > i_size_read(bdev->bd_inode))
126 		return -EINVAL;
127 
128 	err = truncate_bdev_range(bdev, mode, start, start + len - 1);
129 	if (err)
130 		return err;
131 
132 	return blkdev_issue_discard(bdev, start >> 9, len >> 9,
133 				    GFP_KERNEL, flags);
134 }
135 
136 static int blk_ioctl_zeroout(struct block_device *bdev, fmode_t mode,
137 		unsigned long arg)
138 {
139 	uint64_t range[2];
140 	uint64_t start, end, len;
141 	int err;
142 
143 	if (!(mode & FMODE_WRITE))
144 		return -EBADF;
145 
146 	if (copy_from_user(range, (void __user *)arg, sizeof(range)))
147 		return -EFAULT;
148 
149 	start = range[0];
150 	len = range[1];
151 	end = start + len - 1;
152 
153 	if (start & 511)
154 		return -EINVAL;
155 	if (len & 511)
156 		return -EINVAL;
157 	if (end >= (uint64_t)i_size_read(bdev->bd_inode))
158 		return -EINVAL;
159 	if (end < start)
160 		return -EINVAL;
161 
162 	/* Invalidate the page cache, including dirty pages */
163 	err = truncate_bdev_range(bdev, mode, start, end);
164 	if (err)
165 		return err;
166 
167 	return blkdev_issue_zeroout(bdev, start >> 9, len >> 9, GFP_KERNEL,
168 			BLKDEV_ZERO_NOUNMAP);
169 }
170 
171 static int put_ushort(unsigned short __user *argp, unsigned short val)
172 {
173 	return put_user(val, argp);
174 }
175 
176 static int put_int(int __user *argp, int val)
177 {
178 	return put_user(val, argp);
179 }
180 
181 static int put_uint(unsigned int __user *argp, unsigned int val)
182 {
183 	return put_user(val, argp);
184 }
185 
186 static int put_long(long __user *argp, long val)
187 {
188 	return put_user(val, argp);
189 }
190 
191 static int put_ulong(unsigned long __user *argp, unsigned long val)
192 {
193 	return put_user(val, argp);
194 }
195 
196 static int put_u64(u64 __user *argp, u64 val)
197 {
198 	return put_user(val, argp);
199 }
200 
201 #ifdef CONFIG_COMPAT
202 static int compat_put_long(compat_long_t __user *argp, long val)
203 {
204 	return put_user(val, argp);
205 }
206 
207 static int compat_put_ulong(compat_ulong_t __user *argp, compat_ulong_t val)
208 {
209 	return put_user(val, argp);
210 }
211 #endif
212 
213 #ifdef CONFIG_COMPAT
214 /*
215  * This is the equivalent of compat_ptr_ioctl(), to be used by block
216  * drivers that implement only commands that are completely compatible
217  * between 32-bit and 64-bit user space
218  */
219 int blkdev_compat_ptr_ioctl(struct block_device *bdev, fmode_t mode,
220 			unsigned cmd, unsigned long arg)
221 {
222 	struct gendisk *disk = bdev->bd_disk;
223 
224 	if (disk->fops->ioctl)
225 		return disk->fops->ioctl(bdev, mode, cmd,
226 					 (unsigned long)compat_ptr(arg));
227 
228 	return -ENOIOCTLCMD;
229 }
230 EXPORT_SYMBOL(blkdev_compat_ptr_ioctl);
231 #endif
232 
233 static int blkdev_pr_register(struct block_device *bdev,
234 		struct pr_registration __user *arg)
235 {
236 	const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
237 	struct pr_registration reg;
238 
239 	if (!capable(CAP_SYS_ADMIN))
240 		return -EPERM;
241 	if (!ops || !ops->pr_register)
242 		return -EOPNOTSUPP;
243 	if (copy_from_user(&reg, arg, sizeof(reg)))
244 		return -EFAULT;
245 
246 	if (reg.flags & ~PR_FL_IGNORE_KEY)
247 		return -EOPNOTSUPP;
248 	return ops->pr_register(bdev, reg.old_key, reg.new_key, reg.flags);
249 }
250 
251 static int blkdev_pr_reserve(struct block_device *bdev,
252 		struct pr_reservation __user *arg)
253 {
254 	const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
255 	struct pr_reservation rsv;
256 
257 	if (!capable(CAP_SYS_ADMIN))
258 		return -EPERM;
259 	if (!ops || !ops->pr_reserve)
260 		return -EOPNOTSUPP;
261 	if (copy_from_user(&rsv, arg, sizeof(rsv)))
262 		return -EFAULT;
263 
264 	if (rsv.flags & ~PR_FL_IGNORE_KEY)
265 		return -EOPNOTSUPP;
266 	return ops->pr_reserve(bdev, rsv.key, rsv.type, rsv.flags);
267 }
268 
269 static int blkdev_pr_release(struct block_device *bdev,
270 		struct pr_reservation __user *arg)
271 {
272 	const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
273 	struct pr_reservation rsv;
274 
275 	if (!capable(CAP_SYS_ADMIN))
276 		return -EPERM;
277 	if (!ops || !ops->pr_release)
278 		return -EOPNOTSUPP;
279 	if (copy_from_user(&rsv, arg, sizeof(rsv)))
280 		return -EFAULT;
281 
282 	if (rsv.flags)
283 		return -EOPNOTSUPP;
284 	return ops->pr_release(bdev, rsv.key, rsv.type);
285 }
286 
287 static int blkdev_pr_preempt(struct block_device *bdev,
288 		struct pr_preempt __user *arg, bool abort)
289 {
290 	const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
291 	struct pr_preempt p;
292 
293 	if (!capable(CAP_SYS_ADMIN))
294 		return -EPERM;
295 	if (!ops || !ops->pr_preempt)
296 		return -EOPNOTSUPP;
297 	if (copy_from_user(&p, arg, sizeof(p)))
298 		return -EFAULT;
299 
300 	if (p.flags)
301 		return -EOPNOTSUPP;
302 	return ops->pr_preempt(bdev, p.old_key, p.new_key, p.type, abort);
303 }
304 
305 static int blkdev_pr_clear(struct block_device *bdev,
306 		struct pr_clear __user *arg)
307 {
308 	const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
309 	struct pr_clear c;
310 
311 	if (!capable(CAP_SYS_ADMIN))
312 		return -EPERM;
313 	if (!ops || !ops->pr_clear)
314 		return -EOPNOTSUPP;
315 	if (copy_from_user(&c, arg, sizeof(c)))
316 		return -EFAULT;
317 
318 	if (c.flags)
319 		return -EOPNOTSUPP;
320 	return ops->pr_clear(bdev, c.key);
321 }
322 
323 static int blkdev_flushbuf(struct block_device *bdev, fmode_t mode,
324 		unsigned cmd, unsigned long arg)
325 {
326 	if (!capable(CAP_SYS_ADMIN))
327 		return -EACCES;
328 	fsync_bdev(bdev);
329 	invalidate_bdev(bdev);
330 	return 0;
331 }
332 
333 static int blkdev_roset(struct block_device *bdev, fmode_t mode,
334 		unsigned cmd, unsigned long arg)
335 {
336 	int ret, n;
337 
338 	if (!capable(CAP_SYS_ADMIN))
339 		return -EACCES;
340 
341 	if (get_user(n, (int __user *)arg))
342 		return -EFAULT;
343 	if (bdev->bd_disk->fops->set_read_only) {
344 		ret = bdev->bd_disk->fops->set_read_only(bdev, n);
345 		if (ret)
346 			return ret;
347 	}
348 	bdev->bd_read_only = n;
349 	return 0;
350 }
351 
352 static int blkdev_getgeo(struct block_device *bdev,
353 		struct hd_geometry __user *argp)
354 {
355 	struct gendisk *disk = bdev->bd_disk;
356 	struct hd_geometry geo;
357 	int ret;
358 
359 	if (!argp)
360 		return -EINVAL;
361 	if (!disk->fops->getgeo)
362 		return -ENOTTY;
363 
364 	/*
365 	 * We need to set the startsect first, the driver may
366 	 * want to override it.
367 	 */
368 	memset(&geo, 0, sizeof(geo));
369 	geo.start = get_start_sect(bdev);
370 	ret = disk->fops->getgeo(bdev, &geo);
371 	if (ret)
372 		return ret;
373 	if (copy_to_user(argp, &geo, sizeof(geo)))
374 		return -EFAULT;
375 	return 0;
376 }
377 
378 #ifdef CONFIG_COMPAT
379 struct compat_hd_geometry {
380 	unsigned char heads;
381 	unsigned char sectors;
382 	unsigned short cylinders;
383 	u32 start;
384 };
385 
386 static int compat_hdio_getgeo(struct block_device *bdev,
387 			      struct compat_hd_geometry __user *ugeo)
388 {
389 	struct gendisk *disk = bdev->bd_disk;
390 	struct hd_geometry geo;
391 	int ret;
392 
393 	if (!ugeo)
394 		return -EINVAL;
395 	if (!disk->fops->getgeo)
396 		return -ENOTTY;
397 
398 	memset(&geo, 0, sizeof(geo));
399 	/*
400 	 * We need to set the startsect first, the driver may
401 	 * want to override it.
402 	 */
403 	geo.start = get_start_sect(bdev);
404 	ret = disk->fops->getgeo(bdev, &geo);
405 	if (ret)
406 		return ret;
407 
408 	ret = copy_to_user(ugeo, &geo, 4);
409 	ret |= put_user(geo.start, &ugeo->start);
410 	if (ret)
411 		ret = -EFAULT;
412 
413 	return ret;
414 }
415 #endif
416 
417 /* set the logical block size */
418 static int blkdev_bszset(struct block_device *bdev, fmode_t mode,
419 		int __user *argp)
420 {
421 	int ret, n;
422 
423 	if (!capable(CAP_SYS_ADMIN))
424 		return -EACCES;
425 	if (!argp)
426 		return -EINVAL;
427 	if (get_user(n, argp))
428 		return -EFAULT;
429 
430 	if (mode & FMODE_EXCL)
431 		return set_blocksize(bdev, n);
432 
433 	if (IS_ERR(blkdev_get_by_dev(bdev->bd_dev, mode | FMODE_EXCL, &bdev)))
434 		return -EBUSY;
435 	ret = set_blocksize(bdev, n);
436 	blkdev_put(bdev, mode | FMODE_EXCL);
437 
438 	return ret;
439 }
440 
441 /*
442  * Common commands that are handled the same way on native and compat
443  * user space. Note the separate arg/argp parameters that are needed
444  * to deal with the compat_ptr() conversion.
445  */
446 static int blkdev_common_ioctl(struct block_device *bdev, fmode_t mode,
447 				unsigned cmd, unsigned long arg, void __user *argp)
448 {
449 	unsigned int max_sectors;
450 
451 	switch (cmd) {
452 	case BLKFLSBUF:
453 		return blkdev_flushbuf(bdev, mode, cmd, arg);
454 	case BLKROSET:
455 		return blkdev_roset(bdev, mode, cmd, arg);
456 	case BLKDISCARD:
457 		return blk_ioctl_discard(bdev, mode, arg, 0);
458 	case BLKSECDISCARD:
459 		return blk_ioctl_discard(bdev, mode, arg,
460 				BLKDEV_DISCARD_SECURE);
461 	case BLKZEROOUT:
462 		return blk_ioctl_zeroout(bdev, mode, arg);
463 	case BLKREPORTZONE:
464 		return blkdev_report_zones_ioctl(bdev, mode, cmd, arg);
465 	case BLKRESETZONE:
466 	case BLKOPENZONE:
467 	case BLKCLOSEZONE:
468 	case BLKFINISHZONE:
469 		return blkdev_zone_mgmt_ioctl(bdev, mode, cmd, arg);
470 	case BLKGETZONESZ:
471 		return put_uint(argp, bdev_zone_sectors(bdev));
472 	case BLKGETNRZONES:
473 		return put_uint(argp, blkdev_nr_zones(bdev->bd_disk));
474 	case BLKROGET:
475 		return put_int(argp, bdev_read_only(bdev) != 0);
476 	case BLKSSZGET: /* get block device logical block size */
477 		return put_int(argp, bdev_logical_block_size(bdev));
478 	case BLKPBSZGET: /* get block device physical block size */
479 		return put_uint(argp, bdev_physical_block_size(bdev));
480 	case BLKIOMIN:
481 		return put_uint(argp, bdev_io_min(bdev));
482 	case BLKIOOPT:
483 		return put_uint(argp, bdev_io_opt(bdev));
484 	case BLKALIGNOFF:
485 		return put_int(argp, bdev_alignment_offset(bdev));
486 	case BLKDISCARDZEROES:
487 		return put_uint(argp, 0);
488 	case BLKSECTGET:
489 		max_sectors = min_t(unsigned int, USHRT_MAX,
490 				    queue_max_sectors(bdev_get_queue(bdev)));
491 		return put_ushort(argp, max_sectors);
492 	case BLKROTATIONAL:
493 		return put_ushort(argp, !blk_queue_nonrot(bdev_get_queue(bdev)));
494 	case BLKRASET:
495 	case BLKFRASET:
496 		if(!capable(CAP_SYS_ADMIN))
497 			return -EACCES;
498 		bdev->bd_bdi->ra_pages = (arg * 512) / PAGE_SIZE;
499 		return 0;
500 	case BLKRRPART:
501 		return blkdev_reread_part(bdev);
502 	case BLKTRACESTART:
503 	case BLKTRACESTOP:
504 	case BLKTRACETEARDOWN:
505 		return blk_trace_ioctl(bdev, cmd, argp);
506 	case IOC_PR_REGISTER:
507 		return blkdev_pr_register(bdev, argp);
508 	case IOC_PR_RESERVE:
509 		return blkdev_pr_reserve(bdev, argp);
510 	case IOC_PR_RELEASE:
511 		return blkdev_pr_release(bdev, argp);
512 	case IOC_PR_PREEMPT:
513 		return blkdev_pr_preempt(bdev, argp, false);
514 	case IOC_PR_PREEMPT_ABORT:
515 		return blkdev_pr_preempt(bdev, argp, true);
516 	case IOC_PR_CLEAR:
517 		return blkdev_pr_clear(bdev, argp);
518 	default:
519 		return -ENOIOCTLCMD;
520 	}
521 }
522 
523 /*
524  * Always keep this in sync with compat_blkdev_ioctl()
525  * to handle all incompatible commands in both functions.
526  *
527  * New commands must be compatible and go into blkdev_common_ioctl
528  */
529 int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
530 			unsigned long arg)
531 {
532 	int ret;
533 	loff_t size;
534 	void __user *argp = (void __user *)arg;
535 
536 	switch (cmd) {
537 	/* These need separate implementations for the data structure */
538 	case HDIO_GETGEO:
539 		return blkdev_getgeo(bdev, argp);
540 	case BLKPG:
541 		return blkpg_ioctl(bdev, argp);
542 
543 	/* Compat mode returns 32-bit data instead of 'long' */
544 	case BLKRAGET:
545 	case BLKFRAGET:
546 		if (!argp)
547 			return -EINVAL;
548 		return put_long(argp, (bdev->bd_bdi->ra_pages*PAGE_SIZE) / 512);
549 	case BLKGETSIZE:
550 		size = i_size_read(bdev->bd_inode);
551 		if ((size >> 9) > ~0UL)
552 			return -EFBIG;
553 		return put_ulong(argp, size >> 9);
554 
555 	/* The data is compatible, but the command number is different */
556 	case BLKBSZGET: /* get block device soft block size (cf. BLKSSZGET) */
557 		return put_int(argp, block_size(bdev));
558 	case BLKBSZSET:
559 		return blkdev_bszset(bdev, mode, argp);
560 	case BLKGETSIZE64:
561 		return put_u64(argp, i_size_read(bdev->bd_inode));
562 
563 	/* Incompatible alignment on i386 */
564 	case BLKTRACESETUP:
565 		return blk_trace_ioctl(bdev, cmd, argp);
566 	default:
567 		break;
568 	}
569 
570 	ret = blkdev_common_ioctl(bdev, mode, cmd, arg, argp);
571 	if (ret != -ENOIOCTLCMD)
572 		return ret;
573 
574 	if (!bdev->bd_disk->fops->ioctl)
575 		return -ENOTTY;
576 	return bdev->bd_disk->fops->ioctl(bdev, mode, cmd, arg);
577 }
578 EXPORT_SYMBOL_GPL(blkdev_ioctl); /* for /dev/raw */
579 
580 #ifdef CONFIG_COMPAT
581 
582 #define BLKBSZGET_32		_IOR(0x12, 112, int)
583 #define BLKBSZSET_32		_IOW(0x12, 113, int)
584 #define BLKGETSIZE64_32		_IOR(0x12, 114, int)
585 
586 /* Most of the generic ioctls are handled in the normal fallback path.
587    This assumes the blkdev's low level compat_ioctl always returns
588    ENOIOCTLCMD for unknown ioctls. */
589 long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg)
590 {
591 	int ret;
592 	void __user *argp = compat_ptr(arg);
593 	struct block_device *bdev = I_BDEV(file->f_mapping->host);
594 	struct gendisk *disk = bdev->bd_disk;
595 	fmode_t mode = file->f_mode;
596 	loff_t size;
597 
598 	/*
599 	 * O_NDELAY can be altered using fcntl(.., F_SETFL, ..), so we have
600 	 * to updated it before every ioctl.
601 	 */
602 	if (file->f_flags & O_NDELAY)
603 		mode |= FMODE_NDELAY;
604 	else
605 		mode &= ~FMODE_NDELAY;
606 
607 	switch (cmd) {
608 	/* These need separate implementations for the data structure */
609 	case HDIO_GETGEO:
610 		return compat_hdio_getgeo(bdev, argp);
611 	case BLKPG:
612 		return compat_blkpg_ioctl(bdev, argp);
613 
614 	/* Compat mode returns 32-bit data instead of 'long' */
615 	case BLKRAGET:
616 	case BLKFRAGET:
617 		if (!argp)
618 			return -EINVAL;
619 		return compat_put_long(argp,
620 			       (bdev->bd_bdi->ra_pages * PAGE_SIZE) / 512);
621 	case BLKGETSIZE:
622 		size = i_size_read(bdev->bd_inode);
623 		if ((size >> 9) > ~0UL)
624 			return -EFBIG;
625 		return compat_put_ulong(argp, size >> 9);
626 
627 	/* The data is compatible, but the command number is different */
628 	case BLKBSZGET_32: /* get the logical block size (cf. BLKSSZGET) */
629 		return put_int(argp, bdev_logical_block_size(bdev));
630 	case BLKBSZSET_32:
631 		return blkdev_bszset(bdev, mode, argp);
632 	case BLKGETSIZE64_32:
633 		return put_u64(argp, i_size_read(bdev->bd_inode));
634 
635 	/* Incompatible alignment on i386 */
636 	case BLKTRACESETUP32:
637 		return blk_trace_ioctl(bdev, cmd, argp);
638 	default:
639 		break;
640 	}
641 
642 	ret = blkdev_common_ioctl(bdev, mode, cmd, arg, argp);
643 	if (ret == -ENOIOCTLCMD && disk->fops->compat_ioctl)
644 		ret = disk->fops->compat_ioctl(bdev, mode, cmd, arg);
645 
646 	return ret;
647 }
648 #endif
649