xref: /linux/block/ioctl.c (revision 6dfafbd0299a60bfb5d5e277fdf100037c7ded07)
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 <linux/pagemap.h>
15 #include <linux/io_uring/cmd.h>
16 #include <linux/blk-integrity.h>
17 #include <uapi/linux/blkdev.h>
18 #include "blk.h"
19 #include "blk-crypto-internal.h"
20 
21 static int blkpg_do_ioctl(struct block_device *bdev,
22 			  struct blkpg_partition __user *upart, int op)
23 {
24 	struct gendisk *disk = bdev->bd_disk;
25 	struct blkpg_partition p;
26 	sector_t start, length, capacity, end;
27 
28 	if (!capable(CAP_SYS_ADMIN))
29 		return -EACCES;
30 	if (copy_from_user(&p, upart, sizeof(struct blkpg_partition)))
31 		return -EFAULT;
32 	if (bdev_is_partition(bdev))
33 		return -EINVAL;
34 
35 	if (p.pno <= 0)
36 		return -EINVAL;
37 
38 	if (op == BLKPG_DEL_PARTITION)
39 		return bdev_del_partition(disk, p.pno);
40 
41 	if (p.start < 0 || p.length <= 0 || LLONG_MAX - p.length < p.start)
42 		return -EINVAL;
43 	/* Check that the partition is aligned to the block size */
44 	if (!IS_ALIGNED(p.start | p.length, bdev_logical_block_size(bdev)))
45 		return -EINVAL;
46 
47 	start = p.start >> SECTOR_SHIFT;
48 	length = p.length >> SECTOR_SHIFT;
49 	capacity = get_capacity(disk);
50 
51 	if (check_add_overflow(start, length, &end))
52 		return -EINVAL;
53 
54 	if (start >= capacity || end > capacity)
55 		return -EINVAL;
56 
57 	switch (op) {
58 	case BLKPG_ADD_PARTITION:
59 		return bdev_add_partition(disk, p.pno, start, length);
60 	case BLKPG_RESIZE_PARTITION:
61 		return bdev_resize_partition(disk, p.pno, start, length);
62 	default:
63 		return -EINVAL;
64 	}
65 }
66 
67 static int blkpg_ioctl(struct block_device *bdev,
68 		       struct blkpg_ioctl_arg __user *arg)
69 {
70 	struct blkpg_partition __user *udata;
71 	int op;
72 
73 	if (get_user(op, &arg->op) || get_user(udata, &arg->data))
74 		return -EFAULT;
75 
76 	return blkpg_do_ioctl(bdev, udata, op);
77 }
78 
79 #ifdef CONFIG_COMPAT
80 struct compat_blkpg_ioctl_arg {
81 	compat_int_t op;
82 	compat_int_t flags;
83 	compat_int_t datalen;
84 	compat_caddr_t data;
85 };
86 
87 static int compat_blkpg_ioctl(struct block_device *bdev,
88 			      struct compat_blkpg_ioctl_arg __user *arg)
89 {
90 	compat_caddr_t udata;
91 	int op;
92 
93 	if (get_user(op, &arg->op) || get_user(udata, &arg->data))
94 		return -EFAULT;
95 
96 	return blkpg_do_ioctl(bdev, compat_ptr(udata), op);
97 }
98 #endif
99 
100 /*
101  * Check that [start, start + len) is a valid range from the block device's
102  * perspective, including verifying that it can be correctly translated into
103  * logical block addresses.
104  */
105 static int blk_validate_byte_range(struct block_device *bdev,
106 				   uint64_t start, uint64_t len)
107 {
108 	unsigned int bs_mask = bdev_logical_block_size(bdev) - 1;
109 	uint64_t end;
110 
111 	if ((start | len) & bs_mask)
112 		return -EINVAL;
113 	if (!len)
114 		return -EINVAL;
115 	if (check_add_overflow(start, len, &end) || end > bdev_nr_bytes(bdev))
116 		return -EINVAL;
117 
118 	return 0;
119 }
120 
121 static int blk_ioctl_discard(struct block_device *bdev, blk_mode_t mode,
122 		unsigned long arg)
123 {
124 	uint64_t range[2], start, len;
125 	struct bio *prev = NULL, *bio;
126 	sector_t sector, nr_sects;
127 	struct blk_plug plug;
128 	int err;
129 
130 	if (copy_from_user(range, (void __user *)arg, sizeof(range)))
131 		return -EFAULT;
132 	start = range[0];
133 	len = range[1];
134 
135 	if (!bdev_max_discard_sectors(bdev))
136 		return -EOPNOTSUPP;
137 
138 	if (!(mode & BLK_OPEN_WRITE))
139 		return -EBADF;
140 	if (bdev_read_only(bdev))
141 		return -EPERM;
142 	err = blk_validate_byte_range(bdev, start, len);
143 	if (err)
144 		return err;
145 
146 	inode_lock(bdev->bd_mapping->host);
147 	filemap_invalidate_lock(bdev->bd_mapping);
148 	err = truncate_bdev_range(bdev, mode, start, start + len - 1);
149 	if (err)
150 		goto fail;
151 
152 	sector = start >> SECTOR_SHIFT;
153 	nr_sects = len >> SECTOR_SHIFT;
154 
155 	blk_start_plug(&plug);
156 	while (1) {
157 		if (fatal_signal_pending(current)) {
158 			if (prev)
159 				bio_await_chain(prev);
160 			err = -EINTR;
161 			goto out_unplug;
162 		}
163 		bio = blk_alloc_discard_bio(bdev, &sector, &nr_sects,
164 				GFP_KERNEL);
165 		if (!bio)
166 			break;
167 		prev = bio_chain_and_submit(prev, bio);
168 	}
169 	if (prev) {
170 		err = submit_bio_wait(prev);
171 		if (err == -EOPNOTSUPP)
172 			err = 0;
173 		bio_put(prev);
174 	}
175 out_unplug:
176 	blk_finish_plug(&plug);
177 fail:
178 	filemap_invalidate_unlock(bdev->bd_mapping);
179 	inode_unlock(bdev->bd_mapping->host);
180 	return err;
181 }
182 
183 static int blk_ioctl_secure_erase(struct block_device *bdev, blk_mode_t mode,
184 		void __user *argp)
185 {
186 	uint64_t start, len, end;
187 	uint64_t range[2];
188 	int err;
189 
190 	if (!(mode & BLK_OPEN_WRITE))
191 		return -EBADF;
192 	if (!bdev_max_secure_erase_sectors(bdev))
193 		return -EOPNOTSUPP;
194 	if (copy_from_user(range, argp, sizeof(range)))
195 		return -EFAULT;
196 
197 	start = range[0];
198 	len = range[1];
199 	if ((start & 511) || (len & 511))
200 		return -EINVAL;
201 	if (check_add_overflow(start, len, &end) ||
202 	    end > bdev_nr_bytes(bdev))
203 		return -EINVAL;
204 
205 	inode_lock(bdev->bd_mapping->host);
206 	filemap_invalidate_lock(bdev->bd_mapping);
207 	err = truncate_bdev_range(bdev, mode, start, end - 1);
208 	if (!err)
209 		err = blkdev_issue_secure_erase(bdev, start >> 9, len >> 9,
210 						GFP_KERNEL);
211 	filemap_invalidate_unlock(bdev->bd_mapping);
212 	inode_unlock(bdev->bd_mapping->host);
213 	return err;
214 }
215 
216 
217 static int blk_ioctl_zeroout(struct block_device *bdev, blk_mode_t mode,
218 		unsigned long arg)
219 {
220 	uint64_t range[2];
221 	uint64_t start, end, len;
222 	int err;
223 
224 	if (!(mode & BLK_OPEN_WRITE))
225 		return -EBADF;
226 
227 	if (copy_from_user(range, (void __user *)arg, sizeof(range)))
228 		return -EFAULT;
229 
230 	start = range[0];
231 	len = range[1];
232 	end = start + len - 1;
233 
234 	if (start & 511)
235 		return -EINVAL;
236 	if (len & 511)
237 		return -EINVAL;
238 	if (end >= (uint64_t)bdev_nr_bytes(bdev))
239 		return -EINVAL;
240 	if (end < start)
241 		return -EINVAL;
242 
243 	/* Invalidate the page cache, including dirty pages */
244 	inode_lock(bdev->bd_mapping->host);
245 	filemap_invalidate_lock(bdev->bd_mapping);
246 	err = truncate_bdev_range(bdev, mode, start, end);
247 	if (err)
248 		goto fail;
249 
250 	err = blkdev_issue_zeroout(bdev, start >> 9, len >> 9, GFP_KERNEL,
251 				   BLKDEV_ZERO_NOUNMAP | BLKDEV_ZERO_KILLABLE);
252 
253 fail:
254 	filemap_invalidate_unlock(bdev->bd_mapping);
255 	inode_unlock(bdev->bd_mapping->host);
256 	return err;
257 }
258 
259 static int put_ushort(unsigned short __user *argp, unsigned short val)
260 {
261 	return put_user(val, argp);
262 }
263 
264 static int put_int(int __user *argp, int val)
265 {
266 	return put_user(val, argp);
267 }
268 
269 static int put_uint(unsigned int __user *argp, unsigned int val)
270 {
271 	return put_user(val, argp);
272 }
273 
274 static int put_long(long __user *argp, long val)
275 {
276 	return put_user(val, argp);
277 }
278 
279 static int put_ulong(unsigned long __user *argp, unsigned long val)
280 {
281 	return put_user(val, argp);
282 }
283 
284 static int put_u64(u64 __user *argp, u64 val)
285 {
286 	return put_user(val, argp);
287 }
288 
289 #ifdef CONFIG_COMPAT
290 static int compat_put_long(compat_long_t __user *argp, long val)
291 {
292 	return put_user(val, argp);
293 }
294 
295 static int compat_put_ulong(compat_ulong_t __user *argp, compat_ulong_t val)
296 {
297 	return put_user(val, argp);
298 }
299 #endif
300 
301 #ifdef CONFIG_COMPAT
302 /*
303  * This is the equivalent of compat_ptr_ioctl(), to be used by block
304  * drivers that implement only commands that are completely compatible
305  * between 32-bit and 64-bit user space
306  */
307 int blkdev_compat_ptr_ioctl(struct block_device *bdev, blk_mode_t mode,
308 			unsigned cmd, unsigned long arg)
309 {
310 	struct gendisk *disk = bdev->bd_disk;
311 
312 	if (disk->fops->ioctl)
313 		return disk->fops->ioctl(bdev, mode, cmd,
314 					 (unsigned long)compat_ptr(arg));
315 
316 	return -ENOIOCTLCMD;
317 }
318 EXPORT_SYMBOL(blkdev_compat_ptr_ioctl);
319 #endif
320 
321 static bool blkdev_pr_allowed(struct block_device *bdev, blk_mode_t mode)
322 {
323 	/* no sense to make reservations for partitions */
324 	if (bdev_is_partition(bdev))
325 		return false;
326 
327 	if (capable(CAP_SYS_ADMIN))
328 		return true;
329 	/*
330 	 * Only allow unprivileged reservations if the file descriptor is open
331 	 * for writing.
332 	 */
333 	return mode & BLK_OPEN_WRITE;
334 }
335 
336 static int blkdev_pr_register(struct block_device *bdev, blk_mode_t mode,
337 		struct pr_registration __user *arg)
338 {
339 	const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
340 	struct pr_registration reg;
341 
342 	if (!blkdev_pr_allowed(bdev, mode))
343 		return -EPERM;
344 	if (!ops || !ops->pr_register)
345 		return -EOPNOTSUPP;
346 	if (copy_from_user(&reg, arg, sizeof(reg)))
347 		return -EFAULT;
348 
349 	if (reg.flags & ~PR_FL_IGNORE_KEY)
350 		return -EOPNOTSUPP;
351 	return ops->pr_register(bdev, reg.old_key, reg.new_key, reg.flags);
352 }
353 
354 static int blkdev_pr_reserve(struct block_device *bdev, blk_mode_t mode,
355 		struct pr_reservation __user *arg)
356 {
357 	const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
358 	struct pr_reservation rsv;
359 
360 	if (!blkdev_pr_allowed(bdev, mode))
361 		return -EPERM;
362 	if (!ops || !ops->pr_reserve)
363 		return -EOPNOTSUPP;
364 	if (copy_from_user(&rsv, arg, sizeof(rsv)))
365 		return -EFAULT;
366 
367 	if (rsv.flags & ~PR_FL_IGNORE_KEY)
368 		return -EOPNOTSUPP;
369 	return ops->pr_reserve(bdev, rsv.key, rsv.type, rsv.flags);
370 }
371 
372 static int blkdev_pr_release(struct block_device *bdev, blk_mode_t mode,
373 		struct pr_reservation __user *arg)
374 {
375 	const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
376 	struct pr_reservation rsv;
377 
378 	if (!blkdev_pr_allowed(bdev, mode))
379 		return -EPERM;
380 	if (!ops || !ops->pr_release)
381 		return -EOPNOTSUPP;
382 	if (copy_from_user(&rsv, arg, sizeof(rsv)))
383 		return -EFAULT;
384 
385 	if (rsv.flags)
386 		return -EOPNOTSUPP;
387 	return ops->pr_release(bdev, rsv.key, rsv.type);
388 }
389 
390 static int blkdev_pr_preempt(struct block_device *bdev, blk_mode_t mode,
391 		struct pr_preempt __user *arg, bool abort)
392 {
393 	const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
394 	struct pr_preempt p;
395 
396 	if (!blkdev_pr_allowed(bdev, mode))
397 		return -EPERM;
398 	if (!ops || !ops->pr_preempt)
399 		return -EOPNOTSUPP;
400 	if (copy_from_user(&p, arg, sizeof(p)))
401 		return -EFAULT;
402 
403 	if (p.flags)
404 		return -EOPNOTSUPP;
405 	return ops->pr_preempt(bdev, p.old_key, p.new_key, p.type, abort);
406 }
407 
408 static int blkdev_pr_clear(struct block_device *bdev, blk_mode_t mode,
409 		struct pr_clear __user *arg)
410 {
411 	const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
412 	struct pr_clear c;
413 
414 	if (!blkdev_pr_allowed(bdev, mode))
415 		return -EPERM;
416 	if (!ops || !ops->pr_clear)
417 		return -EOPNOTSUPP;
418 	if (copy_from_user(&c, arg, sizeof(c)))
419 		return -EFAULT;
420 
421 	if (c.flags)
422 		return -EOPNOTSUPP;
423 	return ops->pr_clear(bdev, c.key);
424 }
425 
426 static int blkdev_flushbuf(struct block_device *bdev, unsigned cmd,
427 		unsigned long arg)
428 {
429 	if (!capable(CAP_SYS_ADMIN))
430 		return -EACCES;
431 
432 	mutex_lock(&bdev->bd_holder_lock);
433 	if (bdev->bd_holder_ops && bdev->bd_holder_ops->sync)
434 		bdev->bd_holder_ops->sync(bdev);
435 	else {
436 		mutex_unlock(&bdev->bd_holder_lock);
437 		sync_blockdev(bdev);
438 	}
439 
440 	invalidate_bdev(bdev);
441 	return 0;
442 }
443 
444 static int blkdev_roset(struct block_device *bdev, unsigned cmd,
445 		unsigned long arg)
446 {
447 	int ret, n;
448 
449 	if (!capable(CAP_SYS_ADMIN))
450 		return -EACCES;
451 
452 	if (get_user(n, (int __user *)arg))
453 		return -EFAULT;
454 	if (bdev->bd_disk->fops->set_read_only) {
455 		ret = bdev->bd_disk->fops->set_read_only(bdev, n);
456 		if (ret)
457 			return ret;
458 	}
459 	if (n)
460 		bdev_set_flag(bdev, BD_READ_ONLY);
461 	else
462 		bdev_clear_flag(bdev, BD_READ_ONLY);
463 	return 0;
464 }
465 
466 static int blkdev_getgeo(struct block_device *bdev,
467 		struct hd_geometry __user *argp)
468 {
469 	struct gendisk *disk = bdev->bd_disk;
470 	struct hd_geometry geo;
471 	int ret;
472 
473 	if (!argp)
474 		return -EINVAL;
475 	if (!disk->fops->getgeo)
476 		return -ENOTTY;
477 
478 	/*
479 	 * We need to set the startsect first, the driver may
480 	 * want to override it.
481 	 */
482 	memset(&geo, 0, sizeof(geo));
483 	geo.start = get_start_sect(bdev);
484 	ret = disk->fops->getgeo(disk, &geo);
485 	if (ret)
486 		return ret;
487 	if (copy_to_user(argp, &geo, sizeof(geo)))
488 		return -EFAULT;
489 	return 0;
490 }
491 
492 #ifdef CONFIG_COMPAT
493 struct compat_hd_geometry {
494 	unsigned char heads;
495 	unsigned char sectors;
496 	unsigned short cylinders;
497 	u32 start;
498 };
499 
500 static int compat_hdio_getgeo(struct block_device *bdev,
501 			      struct compat_hd_geometry __user *ugeo)
502 {
503 	struct gendisk *disk = bdev->bd_disk;
504 	struct hd_geometry geo;
505 	int ret;
506 
507 	if (!ugeo)
508 		return -EINVAL;
509 	if (!disk->fops->getgeo)
510 		return -ENOTTY;
511 
512 	memset(&geo, 0, sizeof(geo));
513 	/*
514 	 * We need to set the startsect first, the driver may
515 	 * want to override it.
516 	 */
517 	geo.start = get_start_sect(bdev);
518 	ret = disk->fops->getgeo(disk, &geo);
519 	if (ret)
520 		return ret;
521 
522 	ret = copy_to_user(ugeo, &geo, 4);
523 	ret |= put_user(geo.start, &ugeo->start);
524 	if (ret)
525 		ret = -EFAULT;
526 
527 	return ret;
528 }
529 #endif
530 
531 /* set the logical block size */
532 static int blkdev_bszset(struct file *file, blk_mode_t mode,
533 		int __user *argp)
534 {
535 	// this one might be file_inode(file)->i_rdev - a rare valid
536 	// use of file_inode() for those.
537 	dev_t dev = I_BDEV(file->f_mapping->host)->bd_dev;
538 	struct file *excl_file;
539 	int ret, n;
540 
541 	if (!capable(CAP_SYS_ADMIN))
542 		return -EACCES;
543 	if (!argp)
544 		return -EINVAL;
545 	if (get_user(n, argp))
546 		return -EFAULT;
547 
548 	if (mode & BLK_OPEN_EXCL)
549 		return set_blocksize(file, n);
550 
551 	excl_file = bdev_file_open_by_dev(dev, mode, &dev, NULL);
552 	if (IS_ERR(excl_file))
553 		return -EBUSY;
554 	ret = set_blocksize(excl_file, n);
555 	fput(excl_file);
556 	return ret;
557 }
558 
559 /*
560  * Common commands that are handled the same way on native and compat
561  * user space. Note the separate arg/argp parameters that are needed
562  * to deal with the compat_ptr() conversion.
563  */
564 static int blkdev_common_ioctl(struct block_device *bdev, blk_mode_t mode,
565 			       unsigned int cmd, unsigned long arg,
566 			       void __user *argp)
567 {
568 	unsigned int max_sectors;
569 
570 	switch (cmd) {
571 	case BLKFLSBUF:
572 		return blkdev_flushbuf(bdev, cmd, arg);
573 	case BLKROSET:
574 		return blkdev_roset(bdev, cmd, arg);
575 	case BLKDISCARD:
576 		return blk_ioctl_discard(bdev, mode, arg);
577 	case BLKSECDISCARD:
578 		return blk_ioctl_secure_erase(bdev, mode, argp);
579 	case BLKZEROOUT:
580 		return blk_ioctl_zeroout(bdev, mode, arg);
581 	case BLKGETDISKSEQ:
582 		return put_u64(argp, bdev->bd_disk->diskseq);
583 	case BLKREPORTZONE:
584 	case BLKREPORTZONEV2:
585 		return blkdev_report_zones_ioctl(bdev, cmd, arg);
586 	case BLKRESETZONE:
587 	case BLKOPENZONE:
588 	case BLKCLOSEZONE:
589 	case BLKFINISHZONE:
590 		return blkdev_zone_mgmt_ioctl(bdev, mode, cmd, arg);
591 	case BLKGETZONESZ:
592 		return put_uint(argp, bdev_zone_sectors(bdev));
593 	case BLKGETNRZONES:
594 		return put_uint(argp, bdev_nr_zones(bdev));
595 	case BLKROGET:
596 		return put_int(argp, bdev_read_only(bdev) != 0);
597 	case BLKSSZGET: /* get block device logical block size */
598 		return put_int(argp, bdev_logical_block_size(bdev));
599 	case BLKPBSZGET: /* get block device physical block size */
600 		return put_uint(argp, bdev_physical_block_size(bdev));
601 	case BLKIOMIN:
602 		return put_uint(argp, bdev_io_min(bdev));
603 	case BLKIOOPT:
604 		return put_uint(argp, bdev_io_opt(bdev));
605 	case BLKALIGNOFF:
606 		return put_int(argp, bdev_alignment_offset(bdev));
607 	case BLKDISCARDZEROES:
608 		return put_uint(argp, 0);
609 	case BLKSECTGET:
610 		max_sectors = min_t(unsigned int, USHRT_MAX,
611 				    queue_max_sectors(bdev_get_queue(bdev)));
612 		return put_ushort(argp, max_sectors);
613 	case BLKROTATIONAL:
614 		return put_ushort(argp, !bdev_nonrot(bdev));
615 	case BLKRASET:
616 	case BLKFRASET:
617 		if(!capable(CAP_SYS_ADMIN))
618 			return -EACCES;
619 		bdev->bd_disk->bdi->ra_pages = (arg * 512) / PAGE_SIZE;
620 		return 0;
621 	case BLKRRPART:
622 		if (!capable(CAP_SYS_ADMIN))
623 			return -EACCES;
624 		if (bdev_is_partition(bdev))
625 			return -EINVAL;
626 		return disk_scan_partitions(bdev->bd_disk,
627 				mode | BLK_OPEN_STRICT_SCAN);
628 	case BLKTRACESTART:
629 	case BLKTRACESTOP:
630 	case BLKTRACETEARDOWN:
631 		return blk_trace_ioctl(bdev, cmd, argp);
632 	case BLKCRYPTOIMPORTKEY:
633 	case BLKCRYPTOGENERATEKEY:
634 	case BLKCRYPTOPREPAREKEY:
635 		return blk_crypto_ioctl(bdev, cmd, argp);
636 	case IOC_PR_REGISTER:
637 		return blkdev_pr_register(bdev, mode, argp);
638 	case IOC_PR_RESERVE:
639 		return blkdev_pr_reserve(bdev, mode, argp);
640 	case IOC_PR_RELEASE:
641 		return blkdev_pr_release(bdev, mode, argp);
642 	case IOC_PR_PREEMPT:
643 		return blkdev_pr_preempt(bdev, mode, argp, false);
644 	case IOC_PR_PREEMPT_ABORT:
645 		return blkdev_pr_preempt(bdev, mode, argp, true);
646 	case IOC_PR_CLEAR:
647 		return blkdev_pr_clear(bdev, mode, argp);
648 	default:
649 		return blk_get_meta_cap(bdev, cmd, argp);
650 	}
651 }
652 
653 /*
654  * Always keep this in sync with compat_blkdev_ioctl()
655  * to handle all incompatible commands in both functions.
656  *
657  * New commands must be compatible and go into blkdev_common_ioctl
658  */
659 long blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg)
660 {
661 	struct block_device *bdev = I_BDEV(file->f_mapping->host);
662 	void __user *argp = (void __user *)arg;
663 	blk_mode_t mode = file_to_blk_mode(file);
664 	int ret;
665 
666 	switch (cmd) {
667 	/* These need separate implementations for the data structure */
668 	case HDIO_GETGEO:
669 		return blkdev_getgeo(bdev, argp);
670 	case BLKPG:
671 		return blkpg_ioctl(bdev, argp);
672 
673 	/* Compat mode returns 32-bit data instead of 'long' */
674 	case BLKRAGET:
675 	case BLKFRAGET:
676 		if (!argp)
677 			return -EINVAL;
678 		return put_long(argp,
679 			(bdev->bd_disk->bdi->ra_pages * PAGE_SIZE) / 512);
680 	case BLKGETSIZE:
681 		if (bdev_nr_sectors(bdev) > ~0UL)
682 			return -EFBIG;
683 		return put_ulong(argp, bdev_nr_sectors(bdev));
684 
685 	/* The data is compatible, but the command number is different */
686 	case BLKBSZGET: /* get block device soft block size (cf. BLKSSZGET) */
687 		return put_int(argp, block_size(bdev));
688 	case BLKBSZSET:
689 		return blkdev_bszset(file, mode, argp);
690 	case BLKGETSIZE64:
691 		return put_u64(argp, bdev_nr_bytes(bdev));
692 
693 	/* Incompatible alignment on i386 */
694 	case BLKTRACESETUP:
695 	case BLKTRACESETUP2:
696 		return blk_trace_ioctl(bdev, cmd, argp);
697 	default:
698 		break;
699 	}
700 
701 	ret = blkdev_common_ioctl(bdev, mode, cmd, arg, argp);
702 	if (ret != -ENOIOCTLCMD)
703 		return ret;
704 
705 	if (!bdev->bd_disk->fops->ioctl)
706 		return -ENOTTY;
707 	return bdev->bd_disk->fops->ioctl(bdev, mode, cmd, arg);
708 }
709 
710 #ifdef CONFIG_COMPAT
711 
712 #define BLKBSZGET_32		_IOR(0x12, 112, int)
713 #define BLKBSZSET_32		_IOW(0x12, 113, int)
714 #define BLKGETSIZE64_32		_IOR(0x12, 114, int)
715 
716 /* Most of the generic ioctls are handled in the normal fallback path.
717    This assumes the blkdev's low level compat_ioctl always returns
718    ENOIOCTLCMD for unknown ioctls. */
719 long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg)
720 {
721 	int ret;
722 	void __user *argp = compat_ptr(arg);
723 	struct block_device *bdev = I_BDEV(file->f_mapping->host);
724 	struct gendisk *disk = bdev->bd_disk;
725 	blk_mode_t mode = file_to_blk_mode(file);
726 
727 	switch (cmd) {
728 	/* These need separate implementations for the data structure */
729 	case HDIO_GETGEO:
730 		return compat_hdio_getgeo(bdev, argp);
731 	case BLKPG:
732 		return compat_blkpg_ioctl(bdev, argp);
733 
734 	/* Compat mode returns 32-bit data instead of 'long' */
735 	case BLKRAGET:
736 	case BLKFRAGET:
737 		if (!argp)
738 			return -EINVAL;
739 		return compat_put_long(argp,
740 			(bdev->bd_disk->bdi->ra_pages * PAGE_SIZE) / 512);
741 	case BLKGETSIZE:
742 		if (bdev_nr_sectors(bdev) > ~(compat_ulong_t)0)
743 			return -EFBIG;
744 		return compat_put_ulong(argp, bdev_nr_sectors(bdev));
745 
746 	/* The data is compatible, but the command number is different */
747 	case BLKBSZGET_32: /* get the logical block size (cf. BLKSSZGET) */
748 		return put_int(argp, bdev_logical_block_size(bdev));
749 	case BLKBSZSET_32:
750 		return blkdev_bszset(file, mode, argp);
751 	case BLKGETSIZE64_32:
752 		return put_u64(argp, bdev_nr_bytes(bdev));
753 
754 	/* Incompatible alignment on i386 */
755 	case BLKTRACESETUP32:
756 		return blk_trace_ioctl(bdev, cmd, argp);
757 	default:
758 		break;
759 	}
760 
761 	ret = blkdev_common_ioctl(bdev, mode, cmd, arg, argp);
762 	if (ret == -ENOIOCTLCMD && disk->fops->compat_ioctl)
763 		ret = disk->fops->compat_ioctl(bdev, mode, cmd, arg);
764 
765 	return ret;
766 }
767 #endif
768 
769 struct blk_iou_cmd {
770 	int res;
771 	bool nowait;
772 };
773 
774 static void blk_cmd_complete(struct io_tw_req tw_req, io_tw_token_t tw)
775 {
776 	struct io_uring_cmd *cmd = io_uring_cmd_from_tw(tw_req);
777 	struct blk_iou_cmd *bic = io_uring_cmd_to_pdu(cmd, struct blk_iou_cmd);
778 
779 	if (bic->res == -EAGAIN && bic->nowait)
780 		io_uring_cmd_issue_blocking(cmd);
781 	else
782 		io_uring_cmd_done(cmd, bic->res,
783 				  IO_URING_CMD_TASK_WORK_ISSUE_FLAGS);
784 }
785 
786 static void bio_cmd_bio_end_io(struct bio *bio)
787 {
788 	struct io_uring_cmd *cmd = bio->bi_private;
789 	struct blk_iou_cmd *bic = io_uring_cmd_to_pdu(cmd, struct blk_iou_cmd);
790 
791 	if (unlikely(bio->bi_status) && !bic->res)
792 		bic->res = blk_status_to_errno(bio->bi_status);
793 
794 	io_uring_cmd_do_in_task_lazy(cmd, blk_cmd_complete);
795 	bio_put(bio);
796 }
797 
798 static int blkdev_cmd_discard(struct io_uring_cmd *cmd,
799 			      struct block_device *bdev,
800 			      uint64_t start, uint64_t len, bool nowait)
801 {
802 	struct blk_iou_cmd *bic = io_uring_cmd_to_pdu(cmd, struct blk_iou_cmd);
803 	gfp_t gfp = nowait ? GFP_NOWAIT : GFP_KERNEL;
804 	sector_t sector = start >> SECTOR_SHIFT;
805 	sector_t nr_sects = len >> SECTOR_SHIFT;
806 	struct bio *prev = NULL, *bio;
807 	int err;
808 
809 	if (!bdev_max_discard_sectors(bdev))
810 		return -EOPNOTSUPP;
811 	if (!(file_to_blk_mode(cmd->file) & BLK_OPEN_WRITE))
812 		return -EBADF;
813 	if (bdev_read_only(bdev))
814 		return -EPERM;
815 	err = blk_validate_byte_range(bdev, start, len);
816 	if (err)
817 		return err;
818 
819 	err = filemap_invalidate_pages(bdev->bd_mapping, start,
820 					start + len - 1, nowait);
821 	if (err)
822 		return err;
823 
824 	while (true) {
825 		bio = blk_alloc_discard_bio(bdev, &sector, &nr_sects, gfp);
826 		if (!bio)
827 			break;
828 		if (nowait) {
829 			/*
830 			 * Don't allow multi-bio non-blocking submissions as
831 			 * subsequent bios may fail but we won't get a direct
832 			 * indication of that. Normally, the caller should
833 			 * retry from a blocking context.
834 			 */
835 			if (unlikely(nr_sects)) {
836 				bio_put(bio);
837 				return -EAGAIN;
838 			}
839 			bio->bi_opf |= REQ_NOWAIT;
840 		}
841 
842 		prev = bio_chain_and_submit(prev, bio);
843 	}
844 	if (unlikely(!prev))
845 		return -EAGAIN;
846 	if (unlikely(nr_sects))
847 		bic->res = -EAGAIN;
848 
849 	prev->bi_private = cmd;
850 	prev->bi_end_io = bio_cmd_bio_end_io;
851 	submit_bio(prev);
852 	return -EIOCBQUEUED;
853 }
854 
855 int blkdev_uring_cmd(struct io_uring_cmd *cmd, unsigned int issue_flags)
856 {
857 	struct block_device *bdev = I_BDEV(cmd->file->f_mapping->host);
858 	struct blk_iou_cmd *bic = io_uring_cmd_to_pdu(cmd, struct blk_iou_cmd);
859 	const struct io_uring_sqe *sqe = cmd->sqe;
860 	u32 cmd_op = cmd->cmd_op;
861 	uint64_t start, len;
862 
863 	if (unlikely(sqe->ioprio || sqe->__pad1 || sqe->len ||
864 		     sqe->rw_flags || sqe->file_index))
865 		return -EINVAL;
866 
867 	bic->res = 0;
868 	bic->nowait = issue_flags & IO_URING_F_NONBLOCK;
869 
870 	start = READ_ONCE(sqe->addr);
871 	len = READ_ONCE(sqe->addr3);
872 
873 	switch (cmd_op) {
874 	case BLOCK_URING_CMD_DISCARD:
875 		return blkdev_cmd_discard(cmd, bdev, start, len, bic->nowait);
876 	}
877 	return -EINVAL;
878 }
879