1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2001 Sistina Software (UK) Limited.
4  * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
5  *
6  * This file is released under the GPL.
7  */
8 
9 #include "dm-core.h"
10 #include "dm-rq.h"
11 
12 #include <linux/module.h>
13 #include <linux/vmalloc.h>
14 #include <linux/blkdev.h>
15 #include <linux/blk-integrity.h>
16 #include <linux/namei.h>
17 #include <linux/ctype.h>
18 #include <linux/string.h>
19 #include <linux/slab.h>
20 #include <linux/interrupt.h>
21 #include <linux/mutex.h>
22 #include <linux/delay.h>
23 #include <linux/atomic.h>
24 #include <linux/blk-mq.h>
25 #include <linux/mount.h>
26 #include <linux/dax.h>
27 
28 #define DM_MSG_PREFIX "table"
29 
30 #define NODE_SIZE L1_CACHE_BYTES
31 #define KEYS_PER_NODE (NODE_SIZE / sizeof(sector_t))
32 #define CHILDREN_PER_NODE (KEYS_PER_NODE + 1)
33 
34 /*
35  * Similar to ceiling(log_size(n))
36  */
int_log(unsigned int n,unsigned int base)37 static unsigned int int_log(unsigned int n, unsigned int base)
38 {
39 	int result = 0;
40 
41 	while (n > 1) {
42 		n = dm_div_up(n, base);
43 		result++;
44 	}
45 
46 	return result;
47 }
48 
49 /*
50  * Calculate the index of the child node of the n'th node k'th key.
51  */
get_child(unsigned int n,unsigned int k)52 static inline unsigned int get_child(unsigned int n, unsigned int k)
53 {
54 	return (n * CHILDREN_PER_NODE) + k;
55 }
56 
57 /*
58  * Return the n'th node of level l from table t.
59  */
get_node(struct dm_table * t,unsigned int l,unsigned int n)60 static inline sector_t *get_node(struct dm_table *t,
61 				 unsigned int l, unsigned int n)
62 {
63 	return t->index[l] + (n * KEYS_PER_NODE);
64 }
65 
66 /*
67  * Return the highest key that you could lookup from the n'th
68  * node on level l of the btree.
69  */
high(struct dm_table * t,unsigned int l,unsigned int n)70 static sector_t high(struct dm_table *t, unsigned int l, unsigned int n)
71 {
72 	for (; l < t->depth - 1; l++)
73 		n = get_child(n, CHILDREN_PER_NODE - 1);
74 
75 	if (n >= t->counts[l])
76 		return (sector_t) -1;
77 
78 	return get_node(t, l, n)[KEYS_PER_NODE - 1];
79 }
80 
81 /*
82  * Fills in a level of the btree based on the highs of the level
83  * below it.
84  */
setup_btree_index(unsigned int l,struct dm_table * t)85 static int setup_btree_index(unsigned int l, struct dm_table *t)
86 {
87 	unsigned int n, k;
88 	sector_t *node;
89 
90 	for (n = 0U; n < t->counts[l]; n++) {
91 		node = get_node(t, l, n);
92 
93 		for (k = 0U; k < KEYS_PER_NODE; k++)
94 			node[k] = high(t, l + 1, get_child(n, k));
95 	}
96 
97 	return 0;
98 }
99 
100 /*
101  * highs, and targets are managed as dynamic arrays during a
102  * table load.
103  */
alloc_targets(struct dm_table * t,unsigned int num)104 static int alloc_targets(struct dm_table *t, unsigned int num)
105 {
106 	sector_t *n_highs;
107 	struct dm_target *n_targets;
108 
109 	/*
110 	 * Allocate both the target array and offset array at once.
111 	 */
112 	n_highs = kvcalloc(num, sizeof(struct dm_target) + sizeof(sector_t),
113 			   GFP_KERNEL);
114 	if (!n_highs)
115 		return -ENOMEM;
116 
117 	n_targets = (struct dm_target *) (n_highs + num);
118 
119 	memset(n_highs, -1, sizeof(*n_highs) * num);
120 	kvfree(t->highs);
121 
122 	t->num_allocated = num;
123 	t->highs = n_highs;
124 	t->targets = n_targets;
125 
126 	return 0;
127 }
128 
dm_table_create(struct dm_table ** result,blk_mode_t mode,unsigned int num_targets,struct mapped_device * md)129 int dm_table_create(struct dm_table **result, blk_mode_t mode,
130 		    unsigned int num_targets, struct mapped_device *md)
131 {
132 	struct dm_table *t;
133 
134 	if (num_targets > DM_MAX_TARGETS)
135 		return -EOVERFLOW;
136 
137 	t = kzalloc(sizeof(*t), GFP_KERNEL);
138 
139 	if (!t)
140 		return -ENOMEM;
141 
142 	INIT_LIST_HEAD(&t->devices);
143 	init_rwsem(&t->devices_lock);
144 
145 	if (!num_targets)
146 		num_targets = KEYS_PER_NODE;
147 
148 	num_targets = dm_round_up(num_targets, KEYS_PER_NODE);
149 
150 	if (!num_targets) {
151 		kfree(t);
152 		return -EOVERFLOW;
153 	}
154 
155 	if (alloc_targets(t, num_targets)) {
156 		kfree(t);
157 		return -ENOMEM;
158 	}
159 
160 	t->type = DM_TYPE_NONE;
161 	t->mode = mode;
162 	t->md = md;
163 	t->flush_bypasses_map = true;
164 	*result = t;
165 	return 0;
166 }
167 
free_devices(struct list_head * devices,struct mapped_device * md)168 static void free_devices(struct list_head *devices, struct mapped_device *md)
169 {
170 	struct list_head *tmp, *next;
171 
172 	list_for_each_safe(tmp, next, devices) {
173 		struct dm_dev_internal *dd =
174 		    list_entry(tmp, struct dm_dev_internal, list);
175 		DMWARN("%s: dm_table_destroy: dm_put_device call missing for %s",
176 		       dm_device_name(md), dd->dm_dev->name);
177 		dm_put_table_device(md, dd->dm_dev);
178 		kfree(dd);
179 	}
180 }
181 
182 static void dm_table_destroy_crypto_profile(struct dm_table *t);
183 
dm_table_destroy(struct dm_table * t)184 void dm_table_destroy(struct dm_table *t)
185 {
186 	if (!t)
187 		return;
188 
189 	/* free the indexes */
190 	if (t->depth >= 2)
191 		kvfree(t->index[t->depth - 2]);
192 
193 	/* free the targets */
194 	for (unsigned int i = 0; i < t->num_targets; i++) {
195 		struct dm_target *ti = dm_table_get_target(t, i);
196 
197 		if (ti->type->dtr)
198 			ti->type->dtr(ti);
199 
200 		dm_put_target_type(ti->type);
201 	}
202 
203 	kvfree(t->highs);
204 
205 	/* free the device list */
206 	free_devices(&t->devices, t->md);
207 
208 	dm_free_md_mempools(t->mempools);
209 
210 	dm_table_destroy_crypto_profile(t);
211 
212 	kfree(t);
213 }
214 
215 /*
216  * See if we've already got a device in the list.
217  */
find_device(struct list_head * l,dev_t dev)218 static struct dm_dev_internal *find_device(struct list_head *l, dev_t dev)
219 {
220 	struct dm_dev_internal *dd;
221 
222 	list_for_each_entry(dd, l, list)
223 		if (dd->dm_dev->bdev->bd_dev == dev)
224 			return dd;
225 
226 	return NULL;
227 }
228 
229 /*
230  * If possible, this checks an area of a destination device is invalid.
231  */
device_area_is_invalid(struct dm_target * ti,struct dm_dev * dev,sector_t start,sector_t len,void * data)232 static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev,
233 				  sector_t start, sector_t len, void *data)
234 {
235 	struct queue_limits *limits = data;
236 	struct block_device *bdev = dev->bdev;
237 	sector_t dev_size = bdev_nr_sectors(bdev);
238 	unsigned short logical_block_size_sectors =
239 		limits->logical_block_size >> SECTOR_SHIFT;
240 
241 	if (!dev_size)
242 		return 0;
243 
244 	if ((start >= dev_size) || (start + len > dev_size)) {
245 		DMERR("%s: %pg too small for target: start=%llu, len=%llu, dev_size=%llu",
246 		      dm_device_name(ti->table->md), bdev,
247 		      (unsigned long long)start,
248 		      (unsigned long long)len,
249 		      (unsigned long long)dev_size);
250 		return 1;
251 	}
252 
253 	/*
254 	 * If the target is mapped to zoned block device(s), check
255 	 * that the zones are not partially mapped.
256 	 */
257 	if (bdev_is_zoned(bdev)) {
258 		unsigned int zone_sectors = bdev_zone_sectors(bdev);
259 
260 		if (start & (zone_sectors - 1)) {
261 			DMERR("%s: start=%llu not aligned to h/w zone size %u of %pg",
262 			      dm_device_name(ti->table->md),
263 			      (unsigned long long)start,
264 			      zone_sectors, bdev);
265 			return 1;
266 		}
267 
268 		/*
269 		 * Note: The last zone of a zoned block device may be smaller
270 		 * than other zones. So for a target mapping the end of a
271 		 * zoned block device with such a zone, len would not be zone
272 		 * aligned. We do not allow such last smaller zone to be part
273 		 * of the mapping here to ensure that mappings with multiple
274 		 * devices do not end up with a smaller zone in the middle of
275 		 * the sector range.
276 		 */
277 		if (len & (zone_sectors - 1)) {
278 			DMERR("%s: len=%llu not aligned to h/w zone size %u of %pg",
279 			      dm_device_name(ti->table->md),
280 			      (unsigned long long)len,
281 			      zone_sectors, bdev);
282 			return 1;
283 		}
284 	}
285 
286 	if (logical_block_size_sectors <= 1)
287 		return 0;
288 
289 	if (start & (logical_block_size_sectors - 1)) {
290 		DMERR("%s: start=%llu not aligned to h/w logical block size %u of %pg",
291 		      dm_device_name(ti->table->md),
292 		      (unsigned long long)start,
293 		      limits->logical_block_size, bdev);
294 		return 1;
295 	}
296 
297 	if (len & (logical_block_size_sectors - 1)) {
298 		DMERR("%s: len=%llu not aligned to h/w logical block size %u of %pg",
299 		      dm_device_name(ti->table->md),
300 		      (unsigned long long)len,
301 		      limits->logical_block_size, bdev);
302 		return 1;
303 	}
304 
305 	return 0;
306 }
307 
308 /*
309  * This upgrades the mode on an already open dm_dev, being
310  * careful to leave things as they were if we fail to reopen the
311  * device and not to touch the existing bdev field in case
312  * it is accessed concurrently.
313  */
upgrade_mode(struct dm_dev_internal * dd,blk_mode_t new_mode,struct mapped_device * md)314 static int upgrade_mode(struct dm_dev_internal *dd, blk_mode_t new_mode,
315 			struct mapped_device *md)
316 {
317 	int r;
318 	struct dm_dev *old_dev, *new_dev;
319 
320 	old_dev = dd->dm_dev;
321 
322 	r = dm_get_table_device(md, dd->dm_dev->bdev->bd_dev,
323 				dd->dm_dev->mode | new_mode, &new_dev);
324 	if (r)
325 		return r;
326 
327 	dd->dm_dev = new_dev;
328 	dm_put_table_device(md, old_dev);
329 
330 	return 0;
331 }
332 
333 /*
334  * Note: the __ref annotation is because this function can call the __init
335  * marked early_lookup_bdev when called during early boot code from dm-init.c.
336  */
dm_devt_from_path(const char * path,dev_t * dev_p)337 int __ref dm_devt_from_path(const char *path, dev_t *dev_p)
338 {
339 	int r;
340 	dev_t dev;
341 	unsigned int major, minor;
342 	char dummy;
343 
344 	if (sscanf(path, "%u:%u%c", &major, &minor, &dummy) == 2) {
345 		/* Extract the major/minor numbers */
346 		dev = MKDEV(major, minor);
347 		if (MAJOR(dev) != major || MINOR(dev) != minor)
348 			return -EOVERFLOW;
349 	} else {
350 		r = lookup_bdev(path, &dev);
351 #ifndef MODULE
352 		if (r && system_state < SYSTEM_RUNNING)
353 			r = early_lookup_bdev(path, &dev);
354 #endif
355 		if (r)
356 			return r;
357 	}
358 	*dev_p = dev;
359 	return 0;
360 }
361 EXPORT_SYMBOL(dm_devt_from_path);
362 
363 /*
364  * Add a device to the list, or just increment the usage count if
365  * it's already present.
366  */
dm_get_device(struct dm_target * ti,const char * path,blk_mode_t mode,struct dm_dev ** result)367 int dm_get_device(struct dm_target *ti, const char *path, blk_mode_t mode,
368 		  struct dm_dev **result)
369 {
370 	int r;
371 	dev_t dev;
372 	struct dm_dev_internal *dd;
373 	struct dm_table *t = ti->table;
374 
375 	BUG_ON(!t);
376 
377 	r = dm_devt_from_path(path, &dev);
378 	if (r)
379 		return r;
380 
381 	if (dev == disk_devt(t->md->disk))
382 		return -EINVAL;
383 
384 	down_write(&t->devices_lock);
385 
386 	dd = find_device(&t->devices, dev);
387 	if (!dd) {
388 		dd = kmalloc(sizeof(*dd), GFP_KERNEL);
389 		if (!dd) {
390 			r = -ENOMEM;
391 			goto unlock_ret_r;
392 		}
393 
394 		r = dm_get_table_device(t->md, dev, mode, &dd->dm_dev);
395 		if (r) {
396 			kfree(dd);
397 			goto unlock_ret_r;
398 		}
399 
400 		refcount_set(&dd->count, 1);
401 		list_add(&dd->list, &t->devices);
402 		goto out;
403 
404 	} else if (dd->dm_dev->mode != (mode | dd->dm_dev->mode)) {
405 		r = upgrade_mode(dd, mode, t->md);
406 		if (r)
407 			goto unlock_ret_r;
408 	}
409 	refcount_inc(&dd->count);
410 out:
411 	up_write(&t->devices_lock);
412 	*result = dd->dm_dev;
413 	return 0;
414 
415 unlock_ret_r:
416 	up_write(&t->devices_lock);
417 	return r;
418 }
419 EXPORT_SYMBOL(dm_get_device);
420 
dm_set_device_limits(struct dm_target * ti,struct dm_dev * dev,sector_t start,sector_t len,void * data)421 static int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
422 				sector_t start, sector_t len, void *data)
423 {
424 	struct queue_limits *limits = data;
425 	struct block_device *bdev = dev->bdev;
426 	struct request_queue *q = bdev_get_queue(bdev);
427 
428 	if (unlikely(!q)) {
429 		DMWARN("%s: Cannot set limits for nonexistent device %pg",
430 		       dm_device_name(ti->table->md), bdev);
431 		return 0;
432 	}
433 
434 	if (blk_stack_limits(limits, &q->limits,
435 			get_start_sect(bdev) + start) < 0)
436 		DMWARN("%s: adding target device %pg caused an alignment inconsistency: "
437 		       "physical_block_size=%u, logical_block_size=%u, "
438 		       "alignment_offset=%u, start=%llu",
439 		       dm_device_name(ti->table->md), bdev,
440 		       q->limits.physical_block_size,
441 		       q->limits.logical_block_size,
442 		       q->limits.alignment_offset,
443 		       (unsigned long long) start << SECTOR_SHIFT);
444 
445 	/*
446 	 * Only stack the integrity profile if the target doesn't have native
447 	 * integrity support.
448 	 */
449 	if (!dm_target_has_integrity(ti->type))
450 		queue_limits_stack_integrity_bdev(limits, bdev);
451 	return 0;
452 }
453 
454 /*
455  * Decrement a device's use count and remove it if necessary.
456  */
dm_put_device(struct dm_target * ti,struct dm_dev * d)457 void dm_put_device(struct dm_target *ti, struct dm_dev *d)
458 {
459 	int found = 0;
460 	struct dm_table *t = ti->table;
461 	struct list_head *devices = &t->devices;
462 	struct dm_dev_internal *dd;
463 
464 	down_write(&t->devices_lock);
465 
466 	list_for_each_entry(dd, devices, list) {
467 		if (dd->dm_dev == d) {
468 			found = 1;
469 			break;
470 		}
471 	}
472 	if (!found) {
473 		DMERR("%s: device %s not in table devices list",
474 		      dm_device_name(t->md), d->name);
475 		goto unlock_ret;
476 	}
477 	if (refcount_dec_and_test(&dd->count)) {
478 		dm_put_table_device(t->md, d);
479 		list_del(&dd->list);
480 		kfree(dd);
481 	}
482 
483 unlock_ret:
484 	up_write(&t->devices_lock);
485 }
486 EXPORT_SYMBOL(dm_put_device);
487 
488 /*
489  * Checks to see if the target joins onto the end of the table.
490  */
adjoin(struct dm_table * t,struct dm_target * ti)491 static int adjoin(struct dm_table *t, struct dm_target *ti)
492 {
493 	struct dm_target *prev;
494 
495 	if (!t->num_targets)
496 		return !ti->begin;
497 
498 	prev = &t->targets[t->num_targets - 1];
499 	return (ti->begin == (prev->begin + prev->len));
500 }
501 
502 /*
503  * Used to dynamically allocate the arg array.
504  *
505  * We do first allocation with GFP_NOIO because dm-mpath and dm-thin must
506  * process messages even if some device is suspended. These messages have a
507  * small fixed number of arguments.
508  *
509  * On the other hand, dm-switch needs to process bulk data using messages and
510  * excessive use of GFP_NOIO could cause trouble.
511  */
realloc_argv(unsigned int * size,char ** old_argv)512 static char **realloc_argv(unsigned int *size, char **old_argv)
513 {
514 	char **argv;
515 	unsigned int new_size;
516 	gfp_t gfp;
517 
518 	if (*size) {
519 		new_size = *size * 2;
520 		gfp = GFP_KERNEL;
521 	} else {
522 		new_size = 8;
523 		gfp = GFP_NOIO;
524 	}
525 	argv = kmalloc_array(new_size, sizeof(*argv), gfp);
526 	if (argv) {
527 		if (old_argv)
528 			memcpy(argv, old_argv, *size * sizeof(*argv));
529 		*size = new_size;
530 	}
531 
532 	kfree(old_argv);
533 	return argv;
534 }
535 
536 /*
537  * Destructively splits up the argument list to pass to ctr.
538  */
dm_split_args(int * argc,char *** argvp,char * input)539 int dm_split_args(int *argc, char ***argvp, char *input)
540 {
541 	char *start, *end = input, *out, **argv = NULL;
542 	unsigned int array_size = 0;
543 
544 	*argc = 0;
545 
546 	if (!input) {
547 		*argvp = NULL;
548 		return 0;
549 	}
550 
551 	argv = realloc_argv(&array_size, argv);
552 	if (!argv)
553 		return -ENOMEM;
554 
555 	while (1) {
556 		/* Skip whitespace */
557 		start = skip_spaces(end);
558 
559 		if (!*start)
560 			break;	/* success, we hit the end */
561 
562 		/* 'out' is used to remove any back-quotes */
563 		end = out = start;
564 		while (*end) {
565 			/* Everything apart from '\0' can be quoted */
566 			if (*end == '\\' && *(end + 1)) {
567 				*out++ = *(end + 1);
568 				end += 2;
569 				continue;
570 			}
571 
572 			if (isspace(*end))
573 				break;	/* end of token */
574 
575 			*out++ = *end++;
576 		}
577 
578 		/* have we already filled the array ? */
579 		if ((*argc + 1) > array_size) {
580 			argv = realloc_argv(&array_size, argv);
581 			if (!argv)
582 				return -ENOMEM;
583 		}
584 
585 		/* we know this is whitespace */
586 		if (*end)
587 			end++;
588 
589 		/* terminate the string and put it in the array */
590 		*out = '\0';
591 		argv[*argc] = start;
592 		(*argc)++;
593 	}
594 
595 	*argvp = argv;
596 	return 0;
597 }
598 
dm_set_stacking_limits(struct queue_limits * limits)599 static void dm_set_stacking_limits(struct queue_limits *limits)
600 {
601 	blk_set_stacking_limits(limits);
602 	limits->features |= BLK_FEAT_IO_STAT | BLK_FEAT_NOWAIT | BLK_FEAT_POLL;
603 }
604 
605 /*
606  * Impose necessary and sufficient conditions on a devices's table such
607  * that any incoming bio which respects its logical_block_size can be
608  * processed successfully.  If it falls across the boundary between
609  * two or more targets, the size of each piece it gets split into must
610  * be compatible with the logical_block_size of the target processing it.
611  */
validate_hardware_logical_block_alignment(struct dm_table * t,struct queue_limits * limits)612 static int validate_hardware_logical_block_alignment(struct dm_table *t,
613 						     struct queue_limits *limits)
614 {
615 	/*
616 	 * This function uses arithmetic modulo the logical_block_size
617 	 * (in units of 512-byte sectors).
618 	 */
619 	unsigned short device_logical_block_size_sects =
620 		limits->logical_block_size >> SECTOR_SHIFT;
621 
622 	/*
623 	 * Offset of the start of the next table entry, mod logical_block_size.
624 	 */
625 	unsigned short next_target_start = 0;
626 
627 	/*
628 	 * Given an aligned bio that extends beyond the end of a
629 	 * target, how many sectors must the next target handle?
630 	 */
631 	unsigned short remaining = 0;
632 
633 	struct dm_target *ti;
634 	struct queue_limits ti_limits;
635 	unsigned int i;
636 
637 	/*
638 	 * Check each entry in the table in turn.
639 	 */
640 	for (i = 0; i < t->num_targets; i++) {
641 		ti = dm_table_get_target(t, i);
642 
643 		dm_set_stacking_limits(&ti_limits);
644 
645 		/* combine all target devices' limits */
646 		if (ti->type->iterate_devices)
647 			ti->type->iterate_devices(ti, dm_set_device_limits,
648 						  &ti_limits);
649 
650 		/*
651 		 * If the remaining sectors fall entirely within this
652 		 * table entry are they compatible with its logical_block_size?
653 		 */
654 		if (remaining < ti->len &&
655 		    remaining & ((ti_limits.logical_block_size >>
656 				  SECTOR_SHIFT) - 1))
657 			break;	/* Error */
658 
659 		next_target_start =
660 		    (unsigned short) ((next_target_start + ti->len) &
661 				      (device_logical_block_size_sects - 1));
662 		remaining = next_target_start ?
663 		    device_logical_block_size_sects - next_target_start : 0;
664 	}
665 
666 	if (remaining) {
667 		DMERR("%s: table line %u (start sect %llu len %llu) "
668 		      "not aligned to h/w logical block size %u",
669 		      dm_device_name(t->md), i,
670 		      (unsigned long long) ti->begin,
671 		      (unsigned long long) ti->len,
672 		      limits->logical_block_size);
673 		return -EINVAL;
674 	}
675 
676 	return 0;
677 }
678 
dm_table_add_target(struct dm_table * t,const char * type,sector_t start,sector_t len,char * params)679 int dm_table_add_target(struct dm_table *t, const char *type,
680 			sector_t start, sector_t len, char *params)
681 {
682 	int r = -EINVAL, argc;
683 	char **argv;
684 	struct dm_target *ti;
685 
686 	if (t->singleton) {
687 		DMERR("%s: target type %s must appear alone in table",
688 		      dm_device_name(t->md), t->targets->type->name);
689 		return -EINVAL;
690 	}
691 
692 	BUG_ON(t->num_targets >= t->num_allocated);
693 
694 	ti = t->targets + t->num_targets;
695 	memset(ti, 0, sizeof(*ti));
696 
697 	if (!len) {
698 		DMERR("%s: zero-length target", dm_device_name(t->md));
699 		return -EINVAL;
700 	}
701 	if (start + len < start || start + len > LLONG_MAX >> SECTOR_SHIFT) {
702 		DMERR("%s: too large device", dm_device_name(t->md));
703 		return -EINVAL;
704 	}
705 
706 	ti->type = dm_get_target_type(type);
707 	if (!ti->type) {
708 		DMERR("%s: %s: unknown target type", dm_device_name(t->md), type);
709 		return -EINVAL;
710 	}
711 
712 	if (dm_target_needs_singleton(ti->type)) {
713 		if (t->num_targets) {
714 			ti->error = "singleton target type must appear alone in table";
715 			goto bad;
716 		}
717 		t->singleton = true;
718 	}
719 
720 	if (dm_target_always_writeable(ti->type) &&
721 	    !(t->mode & BLK_OPEN_WRITE)) {
722 		ti->error = "target type may not be included in a read-only table";
723 		goto bad;
724 	}
725 
726 	if (t->immutable_target_type) {
727 		if (t->immutable_target_type != ti->type) {
728 			ti->error = "immutable target type cannot be mixed with other target types";
729 			goto bad;
730 		}
731 	} else if (dm_target_is_immutable(ti->type)) {
732 		if (t->num_targets) {
733 			ti->error = "immutable target type cannot be mixed with other target types";
734 			goto bad;
735 		}
736 		t->immutable_target_type = ti->type;
737 	}
738 
739 	ti->table = t;
740 	ti->begin = start;
741 	ti->len = len;
742 	ti->error = "Unknown error";
743 
744 	/*
745 	 * Does this target adjoin the previous one ?
746 	 */
747 	if (!adjoin(t, ti)) {
748 		ti->error = "Gap in table";
749 		goto bad;
750 	}
751 
752 	r = dm_split_args(&argc, &argv, params);
753 	if (r) {
754 		ti->error = "couldn't split parameters";
755 		goto bad;
756 	}
757 
758 	r = ti->type->ctr(ti, argc, argv);
759 	kfree(argv);
760 	if (r)
761 		goto bad;
762 
763 	t->highs[t->num_targets++] = ti->begin + ti->len - 1;
764 
765 	if (!ti->num_discard_bios && ti->discards_supported)
766 		DMWARN("%s: %s: ignoring discards_supported because num_discard_bios is zero.",
767 		       dm_device_name(t->md), type);
768 
769 	if (ti->limit_swap_bios && !static_key_enabled(&swap_bios_enabled.key))
770 		static_branch_enable(&swap_bios_enabled);
771 
772 	if (!ti->flush_bypasses_map)
773 		t->flush_bypasses_map = false;
774 
775 	return 0;
776 
777  bad:
778 	DMERR("%s: %s: %s (%pe)", dm_device_name(t->md), type, ti->error, ERR_PTR(r));
779 	dm_put_target_type(ti->type);
780 	return r;
781 }
782 
783 /*
784  * Target argument parsing helpers.
785  */
validate_next_arg(const struct dm_arg * arg,struct dm_arg_set * arg_set,unsigned int * value,char ** error,unsigned int grouped)786 static int validate_next_arg(const struct dm_arg *arg, struct dm_arg_set *arg_set,
787 			     unsigned int *value, char **error, unsigned int grouped)
788 {
789 	const char *arg_str = dm_shift_arg(arg_set);
790 	char dummy;
791 
792 	if (!arg_str ||
793 	    (sscanf(arg_str, "%u%c", value, &dummy) != 1) ||
794 	    (*value < arg->min) ||
795 	    (*value > arg->max) ||
796 	    (grouped && arg_set->argc < *value)) {
797 		*error = arg->error;
798 		return -EINVAL;
799 	}
800 
801 	return 0;
802 }
803 
dm_read_arg(const struct dm_arg * arg,struct dm_arg_set * arg_set,unsigned int * value,char ** error)804 int dm_read_arg(const struct dm_arg *arg, struct dm_arg_set *arg_set,
805 		unsigned int *value, char **error)
806 {
807 	return validate_next_arg(arg, arg_set, value, error, 0);
808 }
809 EXPORT_SYMBOL(dm_read_arg);
810 
dm_read_arg_group(const struct dm_arg * arg,struct dm_arg_set * arg_set,unsigned int * value,char ** error)811 int dm_read_arg_group(const struct dm_arg *arg, struct dm_arg_set *arg_set,
812 		      unsigned int *value, char **error)
813 {
814 	return validate_next_arg(arg, arg_set, value, error, 1);
815 }
816 EXPORT_SYMBOL(dm_read_arg_group);
817 
dm_shift_arg(struct dm_arg_set * as)818 const char *dm_shift_arg(struct dm_arg_set *as)
819 {
820 	char *r;
821 
822 	if (as->argc) {
823 		as->argc--;
824 		r = *as->argv;
825 		as->argv++;
826 		return r;
827 	}
828 
829 	return NULL;
830 }
831 EXPORT_SYMBOL(dm_shift_arg);
832 
dm_consume_args(struct dm_arg_set * as,unsigned int num_args)833 void dm_consume_args(struct dm_arg_set *as, unsigned int num_args)
834 {
835 	BUG_ON(as->argc < num_args);
836 	as->argc -= num_args;
837 	as->argv += num_args;
838 }
839 EXPORT_SYMBOL(dm_consume_args);
840 
__table_type_bio_based(enum dm_queue_mode table_type)841 static bool __table_type_bio_based(enum dm_queue_mode table_type)
842 {
843 	return (table_type == DM_TYPE_BIO_BASED ||
844 		table_type == DM_TYPE_DAX_BIO_BASED);
845 }
846 
__table_type_request_based(enum dm_queue_mode table_type)847 static bool __table_type_request_based(enum dm_queue_mode table_type)
848 {
849 	return table_type == DM_TYPE_REQUEST_BASED;
850 }
851 
dm_table_set_type(struct dm_table * t,enum dm_queue_mode type)852 void dm_table_set_type(struct dm_table *t, enum dm_queue_mode type)
853 {
854 	t->type = type;
855 }
856 EXPORT_SYMBOL_GPL(dm_table_set_type);
857 
858 /* validate the dax capability of the target device span */
device_not_dax_capable(struct dm_target * ti,struct dm_dev * dev,sector_t start,sector_t len,void * data)859 static int device_not_dax_capable(struct dm_target *ti, struct dm_dev *dev,
860 			sector_t start, sector_t len, void *data)
861 {
862 	if (dev->dax_dev)
863 		return false;
864 
865 	DMDEBUG("%pg: error: dax unsupported by block device", dev->bdev);
866 	return true;
867 }
868 
869 /* Check devices support synchronous DAX */
device_not_dax_synchronous_capable(struct dm_target * ti,struct dm_dev * dev,sector_t start,sector_t len,void * data)870 static int device_not_dax_synchronous_capable(struct dm_target *ti, struct dm_dev *dev,
871 					      sector_t start, sector_t len, void *data)
872 {
873 	return !dev->dax_dev || !dax_synchronous(dev->dax_dev);
874 }
875 
dm_table_supports_dax(struct dm_table * t,iterate_devices_callout_fn iterate_fn)876 static bool dm_table_supports_dax(struct dm_table *t,
877 				  iterate_devices_callout_fn iterate_fn)
878 {
879 	/* Ensure that all targets support DAX. */
880 	for (unsigned int i = 0; i < t->num_targets; i++) {
881 		struct dm_target *ti = dm_table_get_target(t, i);
882 
883 		if (!ti->type->direct_access)
884 			return false;
885 
886 		if (dm_target_is_wildcard(ti->type) ||
887 		    !ti->type->iterate_devices ||
888 		    ti->type->iterate_devices(ti, iterate_fn, NULL))
889 			return false;
890 	}
891 
892 	return true;
893 }
894 
device_is_rq_stackable(struct dm_target * ti,struct dm_dev * dev,sector_t start,sector_t len,void * data)895 static int device_is_rq_stackable(struct dm_target *ti, struct dm_dev *dev,
896 				  sector_t start, sector_t len, void *data)
897 {
898 	struct block_device *bdev = dev->bdev;
899 	struct request_queue *q = bdev_get_queue(bdev);
900 
901 	/* request-based cannot stack on partitions! */
902 	if (bdev_is_partition(bdev))
903 		return false;
904 
905 	return queue_is_mq(q);
906 }
907 
dm_table_determine_type(struct dm_table * t)908 static int dm_table_determine_type(struct dm_table *t)
909 {
910 	unsigned int bio_based = 0, request_based = 0, hybrid = 0;
911 	struct dm_target *ti;
912 	struct list_head *devices = dm_table_get_devices(t);
913 	enum dm_queue_mode live_md_type = dm_get_md_type(t->md);
914 
915 	if (t->type != DM_TYPE_NONE) {
916 		/* target already set the table's type */
917 		if (t->type == DM_TYPE_BIO_BASED) {
918 			/* possibly upgrade to a variant of bio-based */
919 			goto verify_bio_based;
920 		}
921 		BUG_ON(t->type == DM_TYPE_DAX_BIO_BASED);
922 		goto verify_rq_based;
923 	}
924 
925 	for (unsigned int i = 0; i < t->num_targets; i++) {
926 		ti = dm_table_get_target(t, i);
927 		if (dm_target_hybrid(ti))
928 			hybrid = 1;
929 		else if (dm_target_request_based(ti))
930 			request_based = 1;
931 		else
932 			bio_based = 1;
933 
934 		if (bio_based && request_based) {
935 			DMERR("Inconsistent table: different target types can't be mixed up");
936 			return -EINVAL;
937 		}
938 	}
939 
940 	if (hybrid && !bio_based && !request_based) {
941 		/*
942 		 * The targets can work either way.
943 		 * Determine the type from the live device.
944 		 * Default to bio-based if device is new.
945 		 */
946 		if (__table_type_request_based(live_md_type))
947 			request_based = 1;
948 		else
949 			bio_based = 1;
950 	}
951 
952 	if (bio_based) {
953 verify_bio_based:
954 		/* We must use this table as bio-based */
955 		t->type = DM_TYPE_BIO_BASED;
956 		if (dm_table_supports_dax(t, device_not_dax_capable) ||
957 		    (list_empty(devices) && live_md_type == DM_TYPE_DAX_BIO_BASED)) {
958 			t->type = DM_TYPE_DAX_BIO_BASED;
959 		}
960 		return 0;
961 	}
962 
963 	BUG_ON(!request_based); /* No targets in this table */
964 
965 	t->type = DM_TYPE_REQUEST_BASED;
966 
967 verify_rq_based:
968 	/*
969 	 * Request-based dm supports only tables that have a single target now.
970 	 * To support multiple targets, request splitting support is needed,
971 	 * and that needs lots of changes in the block-layer.
972 	 * (e.g. request completion process for partial completion.)
973 	 */
974 	if (t->num_targets > 1) {
975 		DMERR("request-based DM doesn't support multiple targets");
976 		return -EINVAL;
977 	}
978 
979 	if (list_empty(devices)) {
980 		int srcu_idx;
981 		struct dm_table *live_table = dm_get_live_table(t->md, &srcu_idx);
982 
983 		/* inherit live table's type */
984 		if (live_table)
985 			t->type = live_table->type;
986 		dm_put_live_table(t->md, srcu_idx);
987 		return 0;
988 	}
989 
990 	ti = dm_table_get_immutable_target(t);
991 	if (!ti) {
992 		DMERR("table load rejected: immutable target is required");
993 		return -EINVAL;
994 	} else if (ti->max_io_len) {
995 		DMERR("table load rejected: immutable target that splits IO is not supported");
996 		return -EINVAL;
997 	}
998 
999 	/* Non-request-stackable devices can't be used for request-based dm */
1000 	if (!ti->type->iterate_devices ||
1001 	    !ti->type->iterate_devices(ti, device_is_rq_stackable, NULL)) {
1002 		DMERR("table load rejected: including non-request-stackable devices");
1003 		return -EINVAL;
1004 	}
1005 
1006 	return 0;
1007 }
1008 
dm_table_get_type(struct dm_table * t)1009 enum dm_queue_mode dm_table_get_type(struct dm_table *t)
1010 {
1011 	return t->type;
1012 }
1013 
dm_table_get_immutable_target_type(struct dm_table * t)1014 struct target_type *dm_table_get_immutable_target_type(struct dm_table *t)
1015 {
1016 	return t->immutable_target_type;
1017 }
1018 
dm_table_get_immutable_target(struct dm_table * t)1019 struct dm_target *dm_table_get_immutable_target(struct dm_table *t)
1020 {
1021 	/* Immutable target is implicitly a singleton */
1022 	if (t->num_targets > 1 ||
1023 	    !dm_target_is_immutable(t->targets[0].type))
1024 		return NULL;
1025 
1026 	return t->targets;
1027 }
1028 
dm_table_get_wildcard_target(struct dm_table * t)1029 struct dm_target *dm_table_get_wildcard_target(struct dm_table *t)
1030 {
1031 	for (unsigned int i = 0; i < t->num_targets; i++) {
1032 		struct dm_target *ti = dm_table_get_target(t, i);
1033 
1034 		if (dm_target_is_wildcard(ti->type))
1035 			return ti;
1036 	}
1037 
1038 	return NULL;
1039 }
1040 
dm_table_request_based(struct dm_table * t)1041 bool dm_table_request_based(struct dm_table *t)
1042 {
1043 	return __table_type_request_based(dm_table_get_type(t));
1044 }
1045 
dm_table_alloc_md_mempools(struct dm_table * t,struct mapped_device * md)1046 static int dm_table_alloc_md_mempools(struct dm_table *t, struct mapped_device *md)
1047 {
1048 	enum dm_queue_mode type = dm_table_get_type(t);
1049 	unsigned int per_io_data_size = 0, front_pad, io_front_pad;
1050 	unsigned int min_pool_size = 0, pool_size;
1051 	struct dm_md_mempools *pools;
1052 	unsigned int bioset_flags = 0;
1053 
1054 	if (unlikely(type == DM_TYPE_NONE)) {
1055 		DMERR("no table type is set, can't allocate mempools");
1056 		return -EINVAL;
1057 	}
1058 
1059 	pools = kzalloc_node(sizeof(*pools), GFP_KERNEL, md->numa_node_id);
1060 	if (!pools)
1061 		return -ENOMEM;
1062 
1063 	if (type == DM_TYPE_REQUEST_BASED) {
1064 		pool_size = dm_get_reserved_rq_based_ios();
1065 		front_pad = offsetof(struct dm_rq_clone_bio_info, clone);
1066 		goto init_bs;
1067 	}
1068 
1069 	if (md->queue->limits.features & BLK_FEAT_POLL)
1070 		bioset_flags |= BIOSET_PERCPU_CACHE;
1071 
1072 	for (unsigned int i = 0; i < t->num_targets; i++) {
1073 		struct dm_target *ti = dm_table_get_target(t, i);
1074 
1075 		per_io_data_size = max(per_io_data_size, ti->per_io_data_size);
1076 		min_pool_size = max(min_pool_size, ti->num_flush_bios);
1077 	}
1078 	pool_size = max(dm_get_reserved_bio_based_ios(), min_pool_size);
1079 	front_pad = roundup(per_io_data_size,
1080 		__alignof__(struct dm_target_io)) + DM_TARGET_IO_BIO_OFFSET;
1081 
1082 	io_front_pad = roundup(per_io_data_size,
1083 		__alignof__(struct dm_io)) + DM_IO_BIO_OFFSET;
1084 	if (bioset_init(&pools->io_bs, pool_size, io_front_pad, bioset_flags))
1085 		goto out_free_pools;
1086 init_bs:
1087 	if (bioset_init(&pools->bs, pool_size, front_pad, 0))
1088 		goto out_free_pools;
1089 
1090 	t->mempools = pools;
1091 	return 0;
1092 
1093 out_free_pools:
1094 	dm_free_md_mempools(pools);
1095 	return -ENOMEM;
1096 }
1097 
setup_indexes(struct dm_table * t)1098 static int setup_indexes(struct dm_table *t)
1099 {
1100 	int i;
1101 	unsigned int total = 0;
1102 	sector_t *indexes;
1103 
1104 	/* allocate the space for *all* the indexes */
1105 	for (i = t->depth - 2; i >= 0; i--) {
1106 		t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE);
1107 		total += t->counts[i];
1108 	}
1109 
1110 	indexes = kvcalloc(total, NODE_SIZE, GFP_KERNEL);
1111 	if (!indexes)
1112 		return -ENOMEM;
1113 
1114 	/* set up internal nodes, bottom-up */
1115 	for (i = t->depth - 2; i >= 0; i--) {
1116 		t->index[i] = indexes;
1117 		indexes += (KEYS_PER_NODE * t->counts[i]);
1118 		setup_btree_index(i, t);
1119 	}
1120 
1121 	return 0;
1122 }
1123 
1124 /*
1125  * Builds the btree to index the map.
1126  */
dm_table_build_index(struct dm_table * t)1127 static int dm_table_build_index(struct dm_table *t)
1128 {
1129 	int r = 0;
1130 	unsigned int leaf_nodes;
1131 
1132 	/* how many indexes will the btree have ? */
1133 	leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE);
1134 	t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE);
1135 
1136 	/* leaf layer has already been set up */
1137 	t->counts[t->depth - 1] = leaf_nodes;
1138 	t->index[t->depth - 1] = t->highs;
1139 
1140 	if (t->depth >= 2)
1141 		r = setup_indexes(t);
1142 
1143 	return r;
1144 }
1145 
1146 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
1147 
1148 struct dm_crypto_profile {
1149 	struct blk_crypto_profile profile;
1150 	struct mapped_device *md;
1151 };
1152 
dm_keyslot_evict_callback(struct dm_target * ti,struct dm_dev * dev,sector_t start,sector_t len,void * data)1153 static int dm_keyslot_evict_callback(struct dm_target *ti, struct dm_dev *dev,
1154 				     sector_t start, sector_t len, void *data)
1155 {
1156 	const struct blk_crypto_key *key = data;
1157 
1158 	blk_crypto_evict_key(dev->bdev, key);
1159 	return 0;
1160 }
1161 
1162 /*
1163  * When an inline encryption key is evicted from a device-mapper device, evict
1164  * it from all the underlying devices.
1165  */
dm_keyslot_evict(struct blk_crypto_profile * profile,const struct blk_crypto_key * key,unsigned int slot)1166 static int dm_keyslot_evict(struct blk_crypto_profile *profile,
1167 			    const struct blk_crypto_key *key, unsigned int slot)
1168 {
1169 	struct mapped_device *md =
1170 		container_of(profile, struct dm_crypto_profile, profile)->md;
1171 	struct dm_table *t;
1172 	int srcu_idx;
1173 
1174 	t = dm_get_live_table(md, &srcu_idx);
1175 	if (!t)
1176 		goto put_live_table;
1177 
1178 	for (unsigned int i = 0; i < t->num_targets; i++) {
1179 		struct dm_target *ti = dm_table_get_target(t, i);
1180 
1181 		if (!ti->type->iterate_devices)
1182 			continue;
1183 		ti->type->iterate_devices(ti, dm_keyslot_evict_callback,
1184 					  (void *)key);
1185 	}
1186 
1187 put_live_table:
1188 	dm_put_live_table(md, srcu_idx);
1189 	return 0;
1190 }
1191 
1192 static int
device_intersect_crypto_capabilities(struct dm_target * ti,struct dm_dev * dev,sector_t start,sector_t len,void * data)1193 device_intersect_crypto_capabilities(struct dm_target *ti, struct dm_dev *dev,
1194 				     sector_t start, sector_t len, void *data)
1195 {
1196 	struct blk_crypto_profile *parent = data;
1197 	struct blk_crypto_profile *child =
1198 		bdev_get_queue(dev->bdev)->crypto_profile;
1199 
1200 	blk_crypto_intersect_capabilities(parent, child);
1201 	return 0;
1202 }
1203 
dm_destroy_crypto_profile(struct blk_crypto_profile * profile)1204 void dm_destroy_crypto_profile(struct blk_crypto_profile *profile)
1205 {
1206 	struct dm_crypto_profile *dmcp = container_of(profile,
1207 						      struct dm_crypto_profile,
1208 						      profile);
1209 
1210 	if (!profile)
1211 		return;
1212 
1213 	blk_crypto_profile_destroy(profile);
1214 	kfree(dmcp);
1215 }
1216 
dm_table_destroy_crypto_profile(struct dm_table * t)1217 static void dm_table_destroy_crypto_profile(struct dm_table *t)
1218 {
1219 	dm_destroy_crypto_profile(t->crypto_profile);
1220 	t->crypto_profile = NULL;
1221 }
1222 
1223 /*
1224  * Constructs and initializes t->crypto_profile with a crypto profile that
1225  * represents the common set of crypto capabilities of the devices described by
1226  * the dm_table.  However, if the constructed crypto profile doesn't support all
1227  * crypto capabilities that are supported by the current mapped_device, it
1228  * returns an error instead, since we don't support removing crypto capabilities
1229  * on table changes.  Finally, if the constructed crypto profile is "empty" (has
1230  * no crypto capabilities at all), it just sets t->crypto_profile to NULL.
1231  */
dm_table_construct_crypto_profile(struct dm_table * t)1232 static int dm_table_construct_crypto_profile(struct dm_table *t)
1233 {
1234 	struct dm_crypto_profile *dmcp;
1235 	struct blk_crypto_profile *profile;
1236 	unsigned int i;
1237 	bool empty_profile = true;
1238 
1239 	dmcp = kmalloc(sizeof(*dmcp), GFP_KERNEL);
1240 	if (!dmcp)
1241 		return -ENOMEM;
1242 	dmcp->md = t->md;
1243 
1244 	profile = &dmcp->profile;
1245 	blk_crypto_profile_init(profile, 0);
1246 	profile->ll_ops.keyslot_evict = dm_keyslot_evict;
1247 	profile->max_dun_bytes_supported = UINT_MAX;
1248 	memset(profile->modes_supported, 0xFF,
1249 	       sizeof(profile->modes_supported));
1250 	profile->key_types_supported = ~0;
1251 
1252 	for (i = 0; i < t->num_targets; i++) {
1253 		struct dm_target *ti = dm_table_get_target(t, i);
1254 
1255 		if (!dm_target_passes_crypto(ti->type)) {
1256 			blk_crypto_intersect_capabilities(profile, NULL);
1257 			break;
1258 		}
1259 		if (!ti->type->iterate_devices)
1260 			continue;
1261 		ti->type->iterate_devices(ti,
1262 					  device_intersect_crypto_capabilities,
1263 					  profile);
1264 	}
1265 
1266 	if (t->md->queue &&
1267 	    !blk_crypto_has_capabilities(profile,
1268 					 t->md->queue->crypto_profile)) {
1269 		DMERR("Inline encryption capabilities of new DM table were more restrictive than the old table's. This is not supported!");
1270 		dm_destroy_crypto_profile(profile);
1271 		return -EINVAL;
1272 	}
1273 
1274 	/*
1275 	 * If the new profile doesn't actually support any crypto capabilities,
1276 	 * we may as well represent it with a NULL profile.
1277 	 */
1278 	for (i = 0; i < ARRAY_SIZE(profile->modes_supported); i++) {
1279 		if (profile->modes_supported[i]) {
1280 			empty_profile = false;
1281 			break;
1282 		}
1283 	}
1284 
1285 	if (empty_profile) {
1286 		dm_destroy_crypto_profile(profile);
1287 		profile = NULL;
1288 	}
1289 
1290 	/*
1291 	 * t->crypto_profile is only set temporarily while the table is being
1292 	 * set up, and it gets set to NULL after the profile has been
1293 	 * transferred to the request_queue.
1294 	 */
1295 	t->crypto_profile = profile;
1296 
1297 	return 0;
1298 }
1299 
dm_update_crypto_profile(struct request_queue * q,struct dm_table * t)1300 static void dm_update_crypto_profile(struct request_queue *q,
1301 				     struct dm_table *t)
1302 {
1303 	if (!t->crypto_profile)
1304 		return;
1305 
1306 	/* Make the crypto profile less restrictive. */
1307 	if (!q->crypto_profile) {
1308 		blk_crypto_register(t->crypto_profile, q);
1309 	} else {
1310 		blk_crypto_update_capabilities(q->crypto_profile,
1311 					       t->crypto_profile);
1312 		dm_destroy_crypto_profile(t->crypto_profile);
1313 	}
1314 	t->crypto_profile = NULL;
1315 }
1316 
1317 #else /* CONFIG_BLK_INLINE_ENCRYPTION */
1318 
dm_table_construct_crypto_profile(struct dm_table * t)1319 static int dm_table_construct_crypto_profile(struct dm_table *t)
1320 {
1321 	return 0;
1322 }
1323 
dm_destroy_crypto_profile(struct blk_crypto_profile * profile)1324 void dm_destroy_crypto_profile(struct blk_crypto_profile *profile)
1325 {
1326 }
1327 
dm_table_destroy_crypto_profile(struct dm_table * t)1328 static void dm_table_destroy_crypto_profile(struct dm_table *t)
1329 {
1330 }
1331 
dm_update_crypto_profile(struct request_queue * q,struct dm_table * t)1332 static void dm_update_crypto_profile(struct request_queue *q,
1333 				     struct dm_table *t)
1334 {
1335 }
1336 
1337 #endif /* !CONFIG_BLK_INLINE_ENCRYPTION */
1338 
1339 /*
1340  * Prepares the table for use by building the indices,
1341  * setting the type, and allocating mempools.
1342  */
dm_table_complete(struct dm_table * t)1343 int dm_table_complete(struct dm_table *t)
1344 {
1345 	int r;
1346 
1347 	r = dm_table_determine_type(t);
1348 	if (r) {
1349 		DMERR("unable to determine table type");
1350 		return r;
1351 	}
1352 
1353 	r = dm_table_build_index(t);
1354 	if (r) {
1355 		DMERR("unable to build btrees");
1356 		return r;
1357 	}
1358 
1359 	r = dm_table_construct_crypto_profile(t);
1360 	if (r) {
1361 		DMERR("could not construct crypto profile.");
1362 		return r;
1363 	}
1364 
1365 	r = dm_table_alloc_md_mempools(t, t->md);
1366 	if (r)
1367 		DMERR("unable to allocate mempools");
1368 
1369 	return r;
1370 }
1371 
1372 static DEFINE_MUTEX(_event_lock);
dm_table_event_callback(struct dm_table * t,void (* fn)(void *),void * context)1373 void dm_table_event_callback(struct dm_table *t,
1374 			     void (*fn)(void *), void *context)
1375 {
1376 	mutex_lock(&_event_lock);
1377 	t->event_fn = fn;
1378 	t->event_context = context;
1379 	mutex_unlock(&_event_lock);
1380 }
1381 
dm_table_event(struct dm_table * t)1382 void dm_table_event(struct dm_table *t)
1383 {
1384 	mutex_lock(&_event_lock);
1385 	if (t->event_fn)
1386 		t->event_fn(t->event_context);
1387 	mutex_unlock(&_event_lock);
1388 }
1389 EXPORT_SYMBOL(dm_table_event);
1390 
dm_table_get_size(struct dm_table * t)1391 inline sector_t dm_table_get_size(struct dm_table *t)
1392 {
1393 	return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0;
1394 }
1395 EXPORT_SYMBOL(dm_table_get_size);
1396 
1397 /*
1398  * Search the btree for the correct target.
1399  *
1400  * Caller should check returned pointer for NULL
1401  * to trap I/O beyond end of device.
1402  */
dm_table_find_target(struct dm_table * t,sector_t sector)1403 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
1404 {
1405 	unsigned int l, n = 0, k = 0;
1406 	sector_t *node;
1407 
1408 	if (unlikely(sector >= dm_table_get_size(t)))
1409 		return NULL;
1410 
1411 	for (l = 0; l < t->depth; l++) {
1412 		n = get_child(n, k);
1413 		node = get_node(t, l, n);
1414 
1415 		for (k = 0; k < KEYS_PER_NODE; k++)
1416 			if (node[k] >= sector)
1417 				break;
1418 	}
1419 
1420 	return &t->targets[(KEYS_PER_NODE * n) + k];
1421 }
1422 
1423 /*
1424  * type->iterate_devices() should be called when the sanity check needs to
1425  * iterate and check all underlying data devices. iterate_devices() will
1426  * iterate all underlying data devices until it encounters a non-zero return
1427  * code, returned by whether the input iterate_devices_callout_fn, or
1428  * iterate_devices() itself internally.
1429  *
1430  * For some target type (e.g. dm-stripe), one call of iterate_devices() may
1431  * iterate multiple underlying devices internally, in which case a non-zero
1432  * return code returned by iterate_devices_callout_fn will stop the iteration
1433  * in advance.
1434  *
1435  * Cases requiring _any_ underlying device supporting some kind of attribute,
1436  * should use the iteration structure like dm_table_any_dev_attr(), or call
1437  * it directly. @func should handle semantics of positive examples, e.g.
1438  * capable of something.
1439  *
1440  * Cases requiring _all_ underlying devices supporting some kind of attribute,
1441  * should use the iteration structure like dm_table_supports_nowait() or
1442  * dm_table_supports_discards(). Or introduce dm_table_all_devs_attr() that
1443  * uses an @anti_func that handle semantics of counter examples, e.g. not
1444  * capable of something. So: return !dm_table_any_dev_attr(t, anti_func, data);
1445  */
dm_table_any_dev_attr(struct dm_table * t,iterate_devices_callout_fn func,void * data)1446 static bool dm_table_any_dev_attr(struct dm_table *t,
1447 				  iterate_devices_callout_fn func, void *data)
1448 {
1449 	for (unsigned int i = 0; i < t->num_targets; i++) {
1450 		struct dm_target *ti = dm_table_get_target(t, i);
1451 
1452 		if (ti->type->iterate_devices &&
1453 		    ti->type->iterate_devices(ti, func, data))
1454 			return true;
1455 	}
1456 
1457 	return false;
1458 }
1459 
count_device(struct dm_target * ti,struct dm_dev * dev,sector_t start,sector_t len,void * data)1460 static int count_device(struct dm_target *ti, struct dm_dev *dev,
1461 			sector_t start, sector_t len, void *data)
1462 {
1463 	unsigned int *num_devices = data;
1464 
1465 	(*num_devices)++;
1466 
1467 	return 0;
1468 }
1469 
1470 /*
1471  * Check whether a table has no data devices attached using each
1472  * target's iterate_devices method.
1473  * Returns false if the result is unknown because a target doesn't
1474  * support iterate_devices.
1475  */
dm_table_has_no_data_devices(struct dm_table * t)1476 bool dm_table_has_no_data_devices(struct dm_table *t)
1477 {
1478 	for (unsigned int i = 0; i < t->num_targets; i++) {
1479 		struct dm_target *ti = dm_table_get_target(t, i);
1480 		unsigned int num_devices = 0;
1481 
1482 		if (!ti->type->iterate_devices)
1483 			return false;
1484 
1485 		ti->type->iterate_devices(ti, count_device, &num_devices);
1486 		if (num_devices)
1487 			return false;
1488 	}
1489 
1490 	return true;
1491 }
1492 
device_not_zoned(struct dm_target * ti,struct dm_dev * dev,sector_t start,sector_t len,void * data)1493 static int device_not_zoned(struct dm_target *ti, struct dm_dev *dev,
1494 			    sector_t start, sector_t len, void *data)
1495 {
1496 	bool *zoned = data;
1497 
1498 	return bdev_is_zoned(dev->bdev) != *zoned;
1499 }
1500 
device_is_zoned_model(struct dm_target * ti,struct dm_dev * dev,sector_t start,sector_t len,void * data)1501 static int device_is_zoned_model(struct dm_target *ti, struct dm_dev *dev,
1502 				 sector_t start, sector_t len, void *data)
1503 {
1504 	return bdev_is_zoned(dev->bdev);
1505 }
1506 
1507 /*
1508  * Check the device zoned model based on the target feature flag. If the target
1509  * has the DM_TARGET_ZONED_HM feature flag set, host-managed zoned devices are
1510  * also accepted but all devices must have the same zoned model. If the target
1511  * has the DM_TARGET_MIXED_ZONED_MODEL feature set, the devices can have any
1512  * zoned model with all zoned devices having the same zone size.
1513  */
dm_table_supports_zoned(struct dm_table * t,bool zoned)1514 static bool dm_table_supports_zoned(struct dm_table *t, bool zoned)
1515 {
1516 	for (unsigned int i = 0; i < t->num_targets; i++) {
1517 		struct dm_target *ti = dm_table_get_target(t, i);
1518 
1519 		/*
1520 		 * For the wildcard target (dm-error), if we do not have a
1521 		 * backing device, we must always return false. If we have a
1522 		 * backing device, the result must depend on checking zoned
1523 		 * model, like for any other target. So for this, check directly
1524 		 * if the target backing device is zoned as we get "false" when
1525 		 * dm-error was set without a backing device.
1526 		 */
1527 		if (dm_target_is_wildcard(ti->type) &&
1528 		    !ti->type->iterate_devices(ti, device_is_zoned_model, NULL))
1529 			return false;
1530 
1531 		if (dm_target_supports_zoned_hm(ti->type)) {
1532 			if (!ti->type->iterate_devices ||
1533 			    ti->type->iterate_devices(ti, device_not_zoned,
1534 						      &zoned))
1535 				return false;
1536 		} else if (!dm_target_supports_mixed_zoned_model(ti->type)) {
1537 			if (zoned)
1538 				return false;
1539 		}
1540 	}
1541 
1542 	return true;
1543 }
1544 
device_not_matches_zone_sectors(struct dm_target * ti,struct dm_dev * dev,sector_t start,sector_t len,void * data)1545 static int device_not_matches_zone_sectors(struct dm_target *ti, struct dm_dev *dev,
1546 					   sector_t start, sector_t len, void *data)
1547 {
1548 	unsigned int *zone_sectors = data;
1549 
1550 	if (!bdev_is_zoned(dev->bdev))
1551 		return 0;
1552 	return bdev_zone_sectors(dev->bdev) != *zone_sectors;
1553 }
1554 
1555 /*
1556  * Check consistency of zoned model and zone sectors across all targets. For
1557  * zone sectors, if the destination device is a zoned block device, it shall
1558  * have the specified zone_sectors.
1559  */
validate_hardware_zoned(struct dm_table * t,bool zoned,unsigned int zone_sectors)1560 static int validate_hardware_zoned(struct dm_table *t, bool zoned,
1561 				   unsigned int zone_sectors)
1562 {
1563 	if (!zoned)
1564 		return 0;
1565 
1566 	if (!dm_table_supports_zoned(t, zoned)) {
1567 		DMERR("%s: zoned model is not consistent across all devices",
1568 		      dm_device_name(t->md));
1569 		return -EINVAL;
1570 	}
1571 
1572 	/* Check zone size validity and compatibility */
1573 	if (!zone_sectors || !is_power_of_2(zone_sectors))
1574 		return -EINVAL;
1575 
1576 	if (dm_table_any_dev_attr(t, device_not_matches_zone_sectors, &zone_sectors)) {
1577 		DMERR("%s: zone sectors is not consistent across all zoned devices",
1578 		      dm_device_name(t->md));
1579 		return -EINVAL;
1580 	}
1581 
1582 	return 0;
1583 }
1584 
1585 /*
1586  * Establish the new table's queue_limits and validate them.
1587  */
dm_calculate_queue_limits(struct dm_table * t,struct queue_limits * limits)1588 int dm_calculate_queue_limits(struct dm_table *t,
1589 			      struct queue_limits *limits)
1590 {
1591 	struct queue_limits ti_limits;
1592 	unsigned int zone_sectors = 0;
1593 	bool zoned = false;
1594 
1595 	dm_set_stacking_limits(limits);
1596 
1597 	t->integrity_supported = true;
1598 	for (unsigned int i = 0; i < t->num_targets; i++) {
1599 		struct dm_target *ti = dm_table_get_target(t, i);
1600 
1601 		if (!dm_target_passes_integrity(ti->type))
1602 			t->integrity_supported = false;
1603 	}
1604 
1605 	for (unsigned int i = 0; i < t->num_targets; i++) {
1606 		struct dm_target *ti = dm_table_get_target(t, i);
1607 
1608 		dm_set_stacking_limits(&ti_limits);
1609 
1610 		if (!ti->type->iterate_devices) {
1611 			/* Set I/O hints portion of queue limits */
1612 			if (ti->type->io_hints)
1613 				ti->type->io_hints(ti, &ti_limits);
1614 			goto combine_limits;
1615 		}
1616 
1617 		/*
1618 		 * Combine queue limits of all the devices this target uses.
1619 		 */
1620 		ti->type->iterate_devices(ti, dm_set_device_limits,
1621 					  &ti_limits);
1622 
1623 		if (!zoned && (ti_limits.features & BLK_FEAT_ZONED)) {
1624 			/*
1625 			 * After stacking all limits, validate all devices
1626 			 * in table support this zoned model and zone sectors.
1627 			 */
1628 			zoned = (ti_limits.features & BLK_FEAT_ZONED);
1629 			zone_sectors = ti_limits.chunk_sectors;
1630 		}
1631 
1632 		/* Set I/O hints portion of queue limits */
1633 		if (ti->type->io_hints)
1634 			ti->type->io_hints(ti, &ti_limits);
1635 
1636 		/*
1637 		 * Check each device area is consistent with the target's
1638 		 * overall queue limits.
1639 		 */
1640 		if (ti->type->iterate_devices(ti, device_area_is_invalid,
1641 					      &ti_limits))
1642 			return -EINVAL;
1643 
1644 combine_limits:
1645 		/*
1646 		 * Merge this target's queue limits into the overall limits
1647 		 * for the table.
1648 		 */
1649 		if (blk_stack_limits(limits, &ti_limits, 0) < 0)
1650 			DMWARN("%s: adding target device (start sect %llu len %llu) "
1651 			       "caused an alignment inconsistency",
1652 			       dm_device_name(t->md),
1653 			       (unsigned long long) ti->begin,
1654 			       (unsigned long long) ti->len);
1655 
1656 		if (t->integrity_supported ||
1657 		    dm_target_has_integrity(ti->type)) {
1658 			if (!queue_limits_stack_integrity(limits, &ti_limits)) {
1659 				DMWARN("%s: adding target device (start sect %llu len %llu) "
1660 				       "disabled integrity support due to incompatibility",
1661 				       dm_device_name(t->md),
1662 				       (unsigned long long) ti->begin,
1663 				       (unsigned long long) ti->len);
1664 				t->integrity_supported = false;
1665 			}
1666 		}
1667 	}
1668 
1669 	/*
1670 	 * Verify that the zoned model and zone sectors, as determined before
1671 	 * any .io_hints override, are the same across all devices in the table.
1672 	 * - this is especially relevant if .io_hints is emulating a disk-managed
1673 	 *   zoned model on host-managed zoned block devices.
1674 	 * BUT...
1675 	 */
1676 	if (limits->features & BLK_FEAT_ZONED) {
1677 		/*
1678 		 * ...IF the above limits stacking determined a zoned model
1679 		 * validate that all of the table's devices conform to it.
1680 		 */
1681 		zoned = limits->features & BLK_FEAT_ZONED;
1682 		zone_sectors = limits->chunk_sectors;
1683 	}
1684 	if (validate_hardware_zoned(t, zoned, zone_sectors))
1685 		return -EINVAL;
1686 
1687 	return validate_hardware_logical_block_alignment(t, limits);
1688 }
1689 
1690 /*
1691  * Check if a target requires flush support even if none of the underlying
1692  * devices need it (e.g. to persist target-specific metadata).
1693  */
dm_table_supports_flush(struct dm_table * t)1694 static bool dm_table_supports_flush(struct dm_table *t)
1695 {
1696 	for (unsigned int i = 0; i < t->num_targets; i++) {
1697 		struct dm_target *ti = dm_table_get_target(t, i);
1698 
1699 		if (ti->num_flush_bios && ti->flush_supported)
1700 			return true;
1701 	}
1702 
1703 	return false;
1704 }
1705 
device_dax_write_cache_enabled(struct dm_target * ti,struct dm_dev * dev,sector_t start,sector_t len,void * data)1706 static int device_dax_write_cache_enabled(struct dm_target *ti,
1707 					  struct dm_dev *dev, sector_t start,
1708 					  sector_t len, void *data)
1709 {
1710 	struct dax_device *dax_dev = dev->dax_dev;
1711 
1712 	if (!dax_dev)
1713 		return false;
1714 
1715 	if (dax_write_cache_enabled(dax_dev))
1716 		return true;
1717 	return false;
1718 }
1719 
device_not_write_zeroes_capable(struct dm_target * ti,struct dm_dev * dev,sector_t start,sector_t len,void * data)1720 static int device_not_write_zeroes_capable(struct dm_target *ti, struct dm_dev *dev,
1721 					   sector_t start, sector_t len, void *data)
1722 {
1723 	struct request_queue *q = bdev_get_queue(dev->bdev);
1724 
1725 	return !q->limits.max_write_zeroes_sectors;
1726 }
1727 
dm_table_supports_write_zeroes(struct dm_table * t)1728 static bool dm_table_supports_write_zeroes(struct dm_table *t)
1729 {
1730 	for (unsigned int i = 0; i < t->num_targets; i++) {
1731 		struct dm_target *ti = dm_table_get_target(t, i);
1732 
1733 		if (!ti->num_write_zeroes_bios)
1734 			return false;
1735 
1736 		if (!ti->type->iterate_devices ||
1737 		    ti->type->iterate_devices(ti, device_not_write_zeroes_capable, NULL))
1738 			return false;
1739 	}
1740 
1741 	return true;
1742 }
1743 
dm_table_supports_nowait(struct dm_table * t)1744 static bool dm_table_supports_nowait(struct dm_table *t)
1745 {
1746 	for (unsigned int i = 0; i < t->num_targets; i++) {
1747 		struct dm_target *ti = dm_table_get_target(t, i);
1748 
1749 		if (!dm_target_supports_nowait(ti->type))
1750 			return false;
1751 	}
1752 
1753 	return true;
1754 }
1755 
device_not_discard_capable(struct dm_target * ti,struct dm_dev * dev,sector_t start,sector_t len,void * data)1756 static int device_not_discard_capable(struct dm_target *ti, struct dm_dev *dev,
1757 				      sector_t start, sector_t len, void *data)
1758 {
1759 	return !bdev_max_discard_sectors(dev->bdev);
1760 }
1761 
dm_table_supports_discards(struct dm_table * t)1762 static bool dm_table_supports_discards(struct dm_table *t)
1763 {
1764 	for (unsigned int i = 0; i < t->num_targets; i++) {
1765 		struct dm_target *ti = dm_table_get_target(t, i);
1766 
1767 		if (!ti->num_discard_bios)
1768 			return false;
1769 
1770 		/*
1771 		 * Either the target provides discard support (as implied by setting
1772 		 * 'discards_supported') or it relies on _all_ data devices having
1773 		 * discard support.
1774 		 */
1775 		if (!ti->discards_supported &&
1776 		    (!ti->type->iterate_devices ||
1777 		     ti->type->iterate_devices(ti, device_not_discard_capable, NULL)))
1778 			return false;
1779 	}
1780 
1781 	return true;
1782 }
1783 
device_not_secure_erase_capable(struct dm_target * ti,struct dm_dev * dev,sector_t start,sector_t len,void * data)1784 static int device_not_secure_erase_capable(struct dm_target *ti,
1785 					   struct dm_dev *dev, sector_t start,
1786 					   sector_t len, void *data)
1787 {
1788 	return !bdev_max_secure_erase_sectors(dev->bdev);
1789 }
1790 
dm_table_supports_secure_erase(struct dm_table * t)1791 static bool dm_table_supports_secure_erase(struct dm_table *t)
1792 {
1793 	for (unsigned int i = 0; i < t->num_targets; i++) {
1794 		struct dm_target *ti = dm_table_get_target(t, i);
1795 
1796 		if (!ti->num_secure_erase_bios)
1797 			return false;
1798 
1799 		if (!ti->type->iterate_devices ||
1800 		    ti->type->iterate_devices(ti, device_not_secure_erase_capable, NULL))
1801 			return false;
1802 	}
1803 
1804 	return true;
1805 }
1806 
device_not_atomic_write_capable(struct dm_target * ti,struct dm_dev * dev,sector_t start,sector_t len,void * data)1807 static int device_not_atomic_write_capable(struct dm_target *ti,
1808 			struct dm_dev *dev, sector_t start,
1809 			sector_t len, void *data)
1810 {
1811 	return !bdev_can_atomic_write(dev->bdev);
1812 }
1813 
dm_table_supports_atomic_writes(struct dm_table * t)1814 static bool dm_table_supports_atomic_writes(struct dm_table *t)
1815 {
1816 	for (unsigned int i = 0; i < t->num_targets; i++) {
1817 		struct dm_target *ti = dm_table_get_target(t, i);
1818 
1819 		if (!dm_target_supports_atomic_writes(ti->type))
1820 			return false;
1821 
1822 		if (!ti->type->iterate_devices)
1823 			return false;
1824 
1825 		if (ti->type->iterate_devices(ti,
1826 			device_not_atomic_write_capable, NULL)) {
1827 			return false;
1828 		}
1829 	}
1830 	return true;
1831 }
1832 
dm_table_set_restrictions(struct dm_table * t,struct request_queue * q,struct queue_limits * limits)1833 int dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
1834 			      struct queue_limits *limits)
1835 {
1836 	int r;
1837 
1838 	if (!dm_table_supports_nowait(t))
1839 		limits->features &= ~BLK_FEAT_NOWAIT;
1840 
1841 	/*
1842 	 * The current polling impementation does not support request based
1843 	 * stacking.
1844 	 */
1845 	if (!__table_type_bio_based(t->type))
1846 		limits->features &= ~BLK_FEAT_POLL;
1847 
1848 	if (!dm_table_supports_discards(t)) {
1849 		limits->max_hw_discard_sectors = 0;
1850 		limits->discard_granularity = 0;
1851 		limits->discard_alignment = 0;
1852 	}
1853 
1854 	if (!dm_table_supports_write_zeroes(t))
1855 		limits->max_write_zeroes_sectors = 0;
1856 
1857 	if (!dm_table_supports_secure_erase(t))
1858 		limits->max_secure_erase_sectors = 0;
1859 
1860 	if (dm_table_supports_flush(t))
1861 		limits->features |= BLK_FEAT_WRITE_CACHE | BLK_FEAT_FUA;
1862 
1863 	if (dm_table_supports_dax(t, device_not_dax_capable)) {
1864 		limits->features |= BLK_FEAT_DAX;
1865 		if (dm_table_supports_dax(t, device_not_dax_synchronous_capable))
1866 			set_dax_synchronous(t->md->dax_dev);
1867 	} else
1868 		limits->features &= ~BLK_FEAT_DAX;
1869 
1870 	if (dm_table_any_dev_attr(t, device_dax_write_cache_enabled, NULL))
1871 		dax_write_cache(t->md->dax_dev, true);
1872 
1873 	/* For a zoned table, setup the zone related queue attributes. */
1874 	if (IS_ENABLED(CONFIG_BLK_DEV_ZONED) &&
1875 	    (limits->features & BLK_FEAT_ZONED)) {
1876 		r = dm_set_zones_restrictions(t, q, limits);
1877 		if (r)
1878 			return r;
1879 	}
1880 
1881 	if (dm_table_supports_atomic_writes(t))
1882 		limits->features |= BLK_FEAT_ATOMIC_WRITES;
1883 
1884 	r = queue_limits_set(q, limits);
1885 	if (r)
1886 		return r;
1887 
1888 	/*
1889 	 * Now that the limits are set, check the zones mapped by the table
1890 	 * and setup the resources for zone append emulation if necessary.
1891 	 */
1892 	if (IS_ENABLED(CONFIG_BLK_DEV_ZONED) &&
1893 	    (limits->features & BLK_FEAT_ZONED)) {
1894 		r = dm_revalidate_zones(t, q);
1895 		if (r)
1896 			return r;
1897 	}
1898 
1899 	dm_update_crypto_profile(q, t);
1900 	return 0;
1901 }
1902 
dm_table_get_devices(struct dm_table * t)1903 struct list_head *dm_table_get_devices(struct dm_table *t)
1904 {
1905 	return &t->devices;
1906 }
1907 
dm_table_get_mode(struct dm_table * t)1908 blk_mode_t dm_table_get_mode(struct dm_table *t)
1909 {
1910 	return t->mode;
1911 }
1912 EXPORT_SYMBOL(dm_table_get_mode);
1913 
1914 enum suspend_mode {
1915 	PRESUSPEND,
1916 	PRESUSPEND_UNDO,
1917 	POSTSUSPEND,
1918 };
1919 
suspend_targets(struct dm_table * t,enum suspend_mode mode)1920 static void suspend_targets(struct dm_table *t, enum suspend_mode mode)
1921 {
1922 	lockdep_assert_held(&t->md->suspend_lock);
1923 
1924 	for (unsigned int i = 0; i < t->num_targets; i++) {
1925 		struct dm_target *ti = dm_table_get_target(t, i);
1926 
1927 		switch (mode) {
1928 		case PRESUSPEND:
1929 			if (ti->type->presuspend)
1930 				ti->type->presuspend(ti);
1931 			break;
1932 		case PRESUSPEND_UNDO:
1933 			if (ti->type->presuspend_undo)
1934 				ti->type->presuspend_undo(ti);
1935 			break;
1936 		case POSTSUSPEND:
1937 			if (ti->type->postsuspend)
1938 				ti->type->postsuspend(ti);
1939 			break;
1940 		}
1941 	}
1942 }
1943 
dm_table_presuspend_targets(struct dm_table * t)1944 void dm_table_presuspend_targets(struct dm_table *t)
1945 {
1946 	if (!t)
1947 		return;
1948 
1949 	suspend_targets(t, PRESUSPEND);
1950 }
1951 
dm_table_presuspend_undo_targets(struct dm_table * t)1952 void dm_table_presuspend_undo_targets(struct dm_table *t)
1953 {
1954 	if (!t)
1955 		return;
1956 
1957 	suspend_targets(t, PRESUSPEND_UNDO);
1958 }
1959 
dm_table_postsuspend_targets(struct dm_table * t)1960 void dm_table_postsuspend_targets(struct dm_table *t)
1961 {
1962 	if (!t)
1963 		return;
1964 
1965 	suspend_targets(t, POSTSUSPEND);
1966 }
1967 
dm_table_resume_targets(struct dm_table * t)1968 int dm_table_resume_targets(struct dm_table *t)
1969 {
1970 	unsigned int i;
1971 	int r = 0;
1972 
1973 	lockdep_assert_held(&t->md->suspend_lock);
1974 
1975 	for (i = 0; i < t->num_targets; i++) {
1976 		struct dm_target *ti = dm_table_get_target(t, i);
1977 
1978 		if (!ti->type->preresume)
1979 			continue;
1980 
1981 		r = ti->type->preresume(ti);
1982 		if (r) {
1983 			DMERR("%s: %s: preresume failed, error = %d",
1984 			      dm_device_name(t->md), ti->type->name, r);
1985 			return r;
1986 		}
1987 	}
1988 
1989 	for (i = 0; i < t->num_targets; i++) {
1990 		struct dm_target *ti = dm_table_get_target(t, i);
1991 
1992 		if (ti->type->resume)
1993 			ti->type->resume(ti);
1994 	}
1995 
1996 	return 0;
1997 }
1998 
dm_table_get_md(struct dm_table * t)1999 struct mapped_device *dm_table_get_md(struct dm_table *t)
2000 {
2001 	return t->md;
2002 }
2003 EXPORT_SYMBOL(dm_table_get_md);
2004 
dm_table_device_name(struct dm_table * t)2005 const char *dm_table_device_name(struct dm_table *t)
2006 {
2007 	return dm_device_name(t->md);
2008 }
2009 EXPORT_SYMBOL_GPL(dm_table_device_name);
2010 
dm_table_run_md_queue_async(struct dm_table * t)2011 void dm_table_run_md_queue_async(struct dm_table *t)
2012 {
2013 	if (!dm_table_request_based(t))
2014 		return;
2015 
2016 	if (t->md->queue)
2017 		blk_mq_run_hw_queues(t->md->queue, true);
2018 }
2019 EXPORT_SYMBOL(dm_table_run_md_queue_async);
2020 
2021