xref: /linux/block/ioctl.c (revision bb5b94f5bbe75470912b70fb08880fc5273aa62d)
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, fmode_t mode)
85 {
86 	struct block_device *tmp;
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 	if (bdev->bd_disk->open_partitions)
93 		return -EBUSY;
94 
95 	/*
96 	 * Reopen the device to revalidate the driver state and force a
97 	 * partition rescan.
98 	 */
99 	mode &= ~FMODE_EXCL;
100 	set_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state);
101 
102 	tmp = blkdev_get_by_dev(bdev->bd_dev, mode, NULL);
103 	if (IS_ERR(tmp))
104 		return PTR_ERR(tmp);
105 	blkdev_put(tmp, mode);
106 	return 0;
107 }
108 
109 static int blk_ioctl_discard(struct block_device *bdev, fmode_t mode,
110 		unsigned long arg, unsigned long flags)
111 {
112 	uint64_t range[2];
113 	uint64_t start, len;
114 	struct request_queue *q = bdev_get_queue(bdev);
115 	int err;
116 
117 	if (!(mode & FMODE_WRITE))
118 		return -EBADF;
119 
120 	if (!blk_queue_discard(q))
121 		return -EOPNOTSUPP;
122 
123 	if (copy_from_user(range, (void __user *)arg, sizeof(range)))
124 		return -EFAULT;
125 
126 	start = range[0];
127 	len = range[1];
128 
129 	if (start & 511)
130 		return -EINVAL;
131 	if (len & 511)
132 		return -EINVAL;
133 
134 	if (start + len > i_size_read(bdev->bd_inode))
135 		return -EINVAL;
136 
137 	err = truncate_bdev_range(bdev, mode, start, start + len - 1);
138 	if (err)
139 		return err;
140 
141 	return blkdev_issue_discard(bdev, start >> 9, len >> 9,
142 				    GFP_KERNEL, flags);
143 }
144 
145 static int blk_ioctl_zeroout(struct block_device *bdev, fmode_t mode,
146 		unsigned long arg)
147 {
148 	uint64_t range[2];
149 	uint64_t start, end, len;
150 	int err;
151 
152 	if (!(mode & FMODE_WRITE))
153 		return -EBADF;
154 
155 	if (copy_from_user(range, (void __user *)arg, sizeof(range)))
156 		return -EFAULT;
157 
158 	start = range[0];
159 	len = range[1];
160 	end = start + len - 1;
161 
162 	if (start & 511)
163 		return -EINVAL;
164 	if (len & 511)
165 		return -EINVAL;
166 	if (end >= (uint64_t)i_size_read(bdev->bd_inode))
167 		return -EINVAL;
168 	if (end < start)
169 		return -EINVAL;
170 
171 	/* Invalidate the page cache, including dirty pages */
172 	err = truncate_bdev_range(bdev, mode, start, end);
173 	if (err)
174 		return err;
175 
176 	return blkdev_issue_zeroout(bdev, start >> 9, len >> 9, GFP_KERNEL,
177 			BLKDEV_ZERO_NOUNMAP);
178 }
179 
180 static int put_ushort(unsigned short __user *argp, unsigned short val)
181 {
182 	return put_user(val, argp);
183 }
184 
185 static int put_int(int __user *argp, int val)
186 {
187 	return put_user(val, argp);
188 }
189 
190 static int put_uint(unsigned int __user *argp, unsigned int val)
191 {
192 	return put_user(val, argp);
193 }
194 
195 static int put_long(long __user *argp, long val)
196 {
197 	return put_user(val, argp);
198 }
199 
200 static int put_ulong(unsigned long __user *argp, unsigned long val)
201 {
202 	return put_user(val, argp);
203 }
204 
205 static int put_u64(u64 __user *argp, u64 val)
206 {
207 	return put_user(val, argp);
208 }
209 
210 #ifdef CONFIG_COMPAT
211 static int compat_put_long(compat_long_t __user *argp, long val)
212 {
213 	return put_user(val, argp);
214 }
215 
216 static int compat_put_ulong(compat_ulong_t __user *argp, compat_ulong_t val)
217 {
218 	return put_user(val, argp);
219 }
220 #endif
221 
222 #ifdef CONFIG_COMPAT
223 /*
224  * This is the equivalent of compat_ptr_ioctl(), to be used by block
225  * drivers that implement only commands that are completely compatible
226  * between 32-bit and 64-bit user space
227  */
228 int blkdev_compat_ptr_ioctl(struct block_device *bdev, fmode_t mode,
229 			unsigned cmd, unsigned long arg)
230 {
231 	struct gendisk *disk = bdev->bd_disk;
232 
233 	if (disk->fops->ioctl)
234 		return disk->fops->ioctl(bdev, mode, cmd,
235 					 (unsigned long)compat_ptr(arg));
236 
237 	return -ENOIOCTLCMD;
238 }
239 EXPORT_SYMBOL(blkdev_compat_ptr_ioctl);
240 #endif
241 
242 static int blkdev_pr_register(struct block_device *bdev,
243 		struct pr_registration __user *arg)
244 {
245 	const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
246 	struct pr_registration reg;
247 
248 	if (!capable(CAP_SYS_ADMIN))
249 		return -EPERM;
250 	if (!ops || !ops->pr_register)
251 		return -EOPNOTSUPP;
252 	if (copy_from_user(&reg, arg, sizeof(reg)))
253 		return -EFAULT;
254 
255 	if (reg.flags & ~PR_FL_IGNORE_KEY)
256 		return -EOPNOTSUPP;
257 	return ops->pr_register(bdev, reg.old_key, reg.new_key, reg.flags);
258 }
259 
260 static int blkdev_pr_reserve(struct block_device *bdev,
261 		struct pr_reservation __user *arg)
262 {
263 	const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
264 	struct pr_reservation rsv;
265 
266 	if (!capable(CAP_SYS_ADMIN))
267 		return -EPERM;
268 	if (!ops || !ops->pr_reserve)
269 		return -EOPNOTSUPP;
270 	if (copy_from_user(&rsv, arg, sizeof(rsv)))
271 		return -EFAULT;
272 
273 	if (rsv.flags & ~PR_FL_IGNORE_KEY)
274 		return -EOPNOTSUPP;
275 	return ops->pr_reserve(bdev, rsv.key, rsv.type, rsv.flags);
276 }
277 
278 static int blkdev_pr_release(struct block_device *bdev,
279 		struct pr_reservation __user *arg)
280 {
281 	const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
282 	struct pr_reservation rsv;
283 
284 	if (!capable(CAP_SYS_ADMIN))
285 		return -EPERM;
286 	if (!ops || !ops->pr_release)
287 		return -EOPNOTSUPP;
288 	if (copy_from_user(&rsv, arg, sizeof(rsv)))
289 		return -EFAULT;
290 
291 	if (rsv.flags)
292 		return -EOPNOTSUPP;
293 	return ops->pr_release(bdev, rsv.key, rsv.type);
294 }
295 
296 static int blkdev_pr_preempt(struct block_device *bdev,
297 		struct pr_preempt __user *arg, bool abort)
298 {
299 	const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
300 	struct pr_preempt p;
301 
302 	if (!capable(CAP_SYS_ADMIN))
303 		return -EPERM;
304 	if (!ops || !ops->pr_preempt)
305 		return -EOPNOTSUPP;
306 	if (copy_from_user(&p, arg, sizeof(p)))
307 		return -EFAULT;
308 
309 	if (p.flags)
310 		return -EOPNOTSUPP;
311 	return ops->pr_preempt(bdev, p.old_key, p.new_key, p.type, abort);
312 }
313 
314 static int blkdev_pr_clear(struct block_device *bdev,
315 		struct pr_clear __user *arg)
316 {
317 	const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
318 	struct pr_clear c;
319 
320 	if (!capable(CAP_SYS_ADMIN))
321 		return -EPERM;
322 	if (!ops || !ops->pr_clear)
323 		return -EOPNOTSUPP;
324 	if (copy_from_user(&c, arg, sizeof(c)))
325 		return -EFAULT;
326 
327 	if (c.flags)
328 		return -EOPNOTSUPP;
329 	return ops->pr_clear(bdev, c.key);
330 }
331 
332 static int blkdev_flushbuf(struct block_device *bdev, fmode_t mode,
333 		unsigned cmd, unsigned long arg)
334 {
335 	if (!capable(CAP_SYS_ADMIN))
336 		return -EACCES;
337 	fsync_bdev(bdev);
338 	invalidate_bdev(bdev);
339 	return 0;
340 }
341 
342 static int blkdev_roset(struct block_device *bdev, fmode_t mode,
343 		unsigned cmd, unsigned long arg)
344 {
345 	int ret, n;
346 
347 	if (!capable(CAP_SYS_ADMIN))
348 		return -EACCES;
349 
350 	if (get_user(n, (int __user *)arg))
351 		return -EFAULT;
352 	if (bdev->bd_disk->fops->set_read_only) {
353 		ret = bdev->bd_disk->fops->set_read_only(bdev, n);
354 		if (ret)
355 			return ret;
356 	}
357 	bdev->bd_read_only = n;
358 	return 0;
359 }
360 
361 static int blkdev_getgeo(struct block_device *bdev,
362 		struct hd_geometry __user *argp)
363 {
364 	struct gendisk *disk = bdev->bd_disk;
365 	struct hd_geometry geo;
366 	int ret;
367 
368 	if (!argp)
369 		return -EINVAL;
370 	if (!disk->fops->getgeo)
371 		return -ENOTTY;
372 
373 	/*
374 	 * We need to set the startsect first, the driver may
375 	 * want to override it.
376 	 */
377 	memset(&geo, 0, sizeof(geo));
378 	geo.start = get_start_sect(bdev);
379 	ret = disk->fops->getgeo(bdev, &geo);
380 	if (ret)
381 		return ret;
382 	if (copy_to_user(argp, &geo, sizeof(geo)))
383 		return -EFAULT;
384 	return 0;
385 }
386 
387 #ifdef CONFIG_COMPAT
388 struct compat_hd_geometry {
389 	unsigned char heads;
390 	unsigned char sectors;
391 	unsigned short cylinders;
392 	u32 start;
393 };
394 
395 static int compat_hdio_getgeo(struct block_device *bdev,
396 			      struct compat_hd_geometry __user *ugeo)
397 {
398 	struct gendisk *disk = bdev->bd_disk;
399 	struct hd_geometry geo;
400 	int ret;
401 
402 	if (!ugeo)
403 		return -EINVAL;
404 	if (!disk->fops->getgeo)
405 		return -ENOTTY;
406 
407 	memset(&geo, 0, sizeof(geo));
408 	/*
409 	 * We need to set the startsect first, the driver may
410 	 * want to override it.
411 	 */
412 	geo.start = get_start_sect(bdev);
413 	ret = disk->fops->getgeo(bdev, &geo);
414 	if (ret)
415 		return ret;
416 
417 	ret = copy_to_user(ugeo, &geo, 4);
418 	ret |= put_user(geo.start, &ugeo->start);
419 	if (ret)
420 		ret = -EFAULT;
421 
422 	return ret;
423 }
424 #endif
425 
426 /* set the logical block size */
427 static int blkdev_bszset(struct block_device *bdev, fmode_t mode,
428 		int __user *argp)
429 {
430 	int ret, n;
431 
432 	if (!capable(CAP_SYS_ADMIN))
433 		return -EACCES;
434 	if (!argp)
435 		return -EINVAL;
436 	if (get_user(n, argp))
437 		return -EFAULT;
438 
439 	if (mode & FMODE_EXCL)
440 		return set_blocksize(bdev, n);
441 
442 	if (IS_ERR(blkdev_get_by_dev(bdev->bd_dev, mode | FMODE_EXCL, &bdev)))
443 		return -EBUSY;
444 	ret = set_blocksize(bdev, n);
445 	blkdev_put(bdev, mode | FMODE_EXCL);
446 
447 	return ret;
448 }
449 
450 /*
451  * Common commands that are handled the same way on native and compat
452  * user space. Note the separate arg/argp parameters that are needed
453  * to deal with the compat_ptr() conversion.
454  */
455 static int blkdev_common_ioctl(struct block_device *bdev, fmode_t mode,
456 				unsigned cmd, unsigned long arg, void __user *argp)
457 {
458 	unsigned int max_sectors;
459 
460 	switch (cmd) {
461 	case BLKFLSBUF:
462 		return blkdev_flushbuf(bdev, mode, cmd, arg);
463 	case BLKROSET:
464 		return blkdev_roset(bdev, mode, cmd, arg);
465 	case BLKDISCARD:
466 		return blk_ioctl_discard(bdev, mode, arg, 0);
467 	case BLKSECDISCARD:
468 		return blk_ioctl_discard(bdev, mode, arg,
469 				BLKDEV_DISCARD_SECURE);
470 	case BLKZEROOUT:
471 		return blk_ioctl_zeroout(bdev, mode, arg);
472 	case BLKREPORTZONE:
473 		return blkdev_report_zones_ioctl(bdev, mode, cmd, arg);
474 	case BLKRESETZONE:
475 	case BLKOPENZONE:
476 	case BLKCLOSEZONE:
477 	case BLKFINISHZONE:
478 		return blkdev_zone_mgmt_ioctl(bdev, mode, cmd, arg);
479 	case BLKGETZONESZ:
480 		return put_uint(argp, bdev_zone_sectors(bdev));
481 	case BLKGETNRZONES:
482 		return put_uint(argp, blkdev_nr_zones(bdev->bd_disk));
483 	case BLKROGET:
484 		return put_int(argp, bdev_read_only(bdev) != 0);
485 	case BLKSSZGET: /* get block device logical block size */
486 		return put_int(argp, bdev_logical_block_size(bdev));
487 	case BLKPBSZGET: /* get block device physical block size */
488 		return put_uint(argp, bdev_physical_block_size(bdev));
489 	case BLKIOMIN:
490 		return put_uint(argp, bdev_io_min(bdev));
491 	case BLKIOOPT:
492 		return put_uint(argp, bdev_io_opt(bdev));
493 	case BLKALIGNOFF:
494 		return put_int(argp, bdev_alignment_offset(bdev));
495 	case BLKDISCARDZEROES:
496 		return put_uint(argp, 0);
497 	case BLKSECTGET:
498 		max_sectors = min_t(unsigned int, USHRT_MAX,
499 				    queue_max_sectors(bdev_get_queue(bdev)));
500 		return put_ushort(argp, max_sectors);
501 	case BLKROTATIONAL:
502 		return put_ushort(argp, !blk_queue_nonrot(bdev_get_queue(bdev)));
503 	case BLKRASET:
504 	case BLKFRASET:
505 		if(!capable(CAP_SYS_ADMIN))
506 			return -EACCES;
507 		bdev->bd_bdi->ra_pages = (arg * 512) / PAGE_SIZE;
508 		return 0;
509 	case BLKRRPART:
510 		return blkdev_reread_part(bdev, mode);
511 	case BLKTRACESTART:
512 	case BLKTRACESTOP:
513 	case BLKTRACETEARDOWN:
514 		return blk_trace_ioctl(bdev, cmd, argp);
515 	case IOC_PR_REGISTER:
516 		return blkdev_pr_register(bdev, argp);
517 	case IOC_PR_RESERVE:
518 		return blkdev_pr_reserve(bdev, argp);
519 	case IOC_PR_RELEASE:
520 		return blkdev_pr_release(bdev, argp);
521 	case IOC_PR_PREEMPT:
522 		return blkdev_pr_preempt(bdev, argp, false);
523 	case IOC_PR_PREEMPT_ABORT:
524 		return blkdev_pr_preempt(bdev, argp, true);
525 	case IOC_PR_CLEAR:
526 		return blkdev_pr_clear(bdev, argp);
527 	default:
528 		return -ENOIOCTLCMD;
529 	}
530 }
531 
532 /*
533  * Always keep this in sync with compat_blkdev_ioctl()
534  * to handle all incompatible commands in both functions.
535  *
536  * New commands must be compatible and go into blkdev_common_ioctl
537  */
538 int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
539 			unsigned long arg)
540 {
541 	int ret;
542 	loff_t size;
543 	void __user *argp = (void __user *)arg;
544 
545 	switch (cmd) {
546 	/* These need separate implementations for the data structure */
547 	case HDIO_GETGEO:
548 		return blkdev_getgeo(bdev, argp);
549 	case BLKPG:
550 		return blkpg_ioctl(bdev, argp);
551 
552 	/* Compat mode returns 32-bit data instead of 'long' */
553 	case BLKRAGET:
554 	case BLKFRAGET:
555 		if (!argp)
556 			return -EINVAL;
557 		return put_long(argp, (bdev->bd_bdi->ra_pages*PAGE_SIZE) / 512);
558 	case BLKGETSIZE:
559 		size = i_size_read(bdev->bd_inode);
560 		if ((size >> 9) > ~0UL)
561 			return -EFBIG;
562 		return put_ulong(argp, size >> 9);
563 
564 	/* The data is compatible, but the command number is different */
565 	case BLKBSZGET: /* get block device soft block size (cf. BLKSSZGET) */
566 		return put_int(argp, block_size(bdev));
567 	case BLKBSZSET:
568 		return blkdev_bszset(bdev, mode, argp);
569 	case BLKGETSIZE64:
570 		return put_u64(argp, i_size_read(bdev->bd_inode));
571 
572 	/* Incompatible alignment on i386 */
573 	case BLKTRACESETUP:
574 		return blk_trace_ioctl(bdev, cmd, argp);
575 	default:
576 		break;
577 	}
578 
579 	ret = blkdev_common_ioctl(bdev, mode, cmd, arg, argp);
580 	if (ret != -ENOIOCTLCMD)
581 		return ret;
582 
583 	if (!bdev->bd_disk->fops->ioctl)
584 		return -ENOTTY;
585 	return bdev->bd_disk->fops->ioctl(bdev, mode, cmd, arg);
586 }
587 EXPORT_SYMBOL_GPL(blkdev_ioctl); /* for /dev/raw */
588 
589 #ifdef CONFIG_COMPAT
590 
591 #define BLKBSZGET_32		_IOR(0x12, 112, int)
592 #define BLKBSZSET_32		_IOW(0x12, 113, int)
593 #define BLKGETSIZE64_32		_IOR(0x12, 114, int)
594 
595 /* Most of the generic ioctls are handled in the normal fallback path.
596    This assumes the blkdev's low level compat_ioctl always returns
597    ENOIOCTLCMD for unknown ioctls. */
598 long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg)
599 {
600 	int ret;
601 	void __user *argp = compat_ptr(arg);
602 	struct block_device *bdev = I_BDEV(file->f_mapping->host);
603 	struct gendisk *disk = bdev->bd_disk;
604 	fmode_t mode = file->f_mode;
605 	loff_t size;
606 
607 	/*
608 	 * O_NDELAY can be altered using fcntl(.., F_SETFL, ..), so we have
609 	 * to updated it before every ioctl.
610 	 */
611 	if (file->f_flags & O_NDELAY)
612 		mode |= FMODE_NDELAY;
613 	else
614 		mode &= ~FMODE_NDELAY;
615 
616 	switch (cmd) {
617 	/* These need separate implementations for the data structure */
618 	case HDIO_GETGEO:
619 		return compat_hdio_getgeo(bdev, argp);
620 	case BLKPG:
621 		return compat_blkpg_ioctl(bdev, argp);
622 
623 	/* Compat mode returns 32-bit data instead of 'long' */
624 	case BLKRAGET:
625 	case BLKFRAGET:
626 		if (!argp)
627 			return -EINVAL;
628 		return compat_put_long(argp,
629 			       (bdev->bd_bdi->ra_pages * PAGE_SIZE) / 512);
630 	case BLKGETSIZE:
631 		size = i_size_read(bdev->bd_inode);
632 		if ((size >> 9) > ~0UL)
633 			return -EFBIG;
634 		return compat_put_ulong(argp, size >> 9);
635 
636 	/* The data is compatible, but the command number is different */
637 	case BLKBSZGET_32: /* get the logical block size (cf. BLKSSZGET) */
638 		return put_int(argp, bdev_logical_block_size(bdev));
639 	case BLKBSZSET_32:
640 		return blkdev_bszset(bdev, mode, argp);
641 	case BLKGETSIZE64_32:
642 		return put_u64(argp, i_size_read(bdev->bd_inode));
643 
644 	/* Incompatible alignment on i386 */
645 	case BLKTRACESETUP32:
646 		return blk_trace_ioctl(bdev, cmd, argp);
647 	default:
648 		break;
649 	}
650 
651 	ret = blkdev_common_ioctl(bdev, mode, cmd, arg, argp);
652 	if (ret == -ENOIOCTLCMD && disk->fops->compat_ioctl)
653 		ret = disk->fops->compat_ioctl(bdev, mode, cmd, arg);
654 
655 	return ret;
656 }
657 #endif
658