xref: /linux/drivers/md/dm-table.c (revision 9b960d8cd6f712cb2c03e2bdd4d5ca058238037f)
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 && old_argv) {
527 		memcpy(argv, old_argv, *size * sizeof(*argv));
528 		*size = new_size;
529 	}
530 
531 	kfree(old_argv);
532 	return argv;
533 }
534 
535 /*
536  * Destructively splits up the argument list to pass to ctr.
537  */
dm_split_args(int * argc,char *** argvp,char * input)538 int dm_split_args(int *argc, char ***argvp, char *input)
539 {
540 	char *start, *end = input, *out, **argv = NULL;
541 	unsigned int array_size = 0;
542 
543 	*argc = 0;
544 
545 	if (!input) {
546 		*argvp = NULL;
547 		return 0;
548 	}
549 
550 	argv = realloc_argv(&array_size, argv);
551 	if (!argv)
552 		return -ENOMEM;
553 
554 	while (1) {
555 		/* Skip whitespace */
556 		start = skip_spaces(end);
557 
558 		if (!*start)
559 			break;	/* success, we hit the end */
560 
561 		/* 'out' is used to remove any back-quotes */
562 		end = out = start;
563 		while (*end) {
564 			/* Everything apart from '\0' can be quoted */
565 			if (*end == '\\' && *(end + 1)) {
566 				*out++ = *(end + 1);
567 				end += 2;
568 				continue;
569 			}
570 
571 			if (isspace(*end))
572 				break;	/* end of token */
573 
574 			*out++ = *end++;
575 		}
576 
577 		/* have we already filled the array ? */
578 		if ((*argc + 1) > array_size) {
579 			argv = realloc_argv(&array_size, argv);
580 			if (!argv)
581 				return -ENOMEM;
582 		}
583 
584 		/* we know this is whitespace */
585 		if (*end)
586 			end++;
587 
588 		/* terminate the string and put it in the array */
589 		*out = '\0';
590 		argv[*argc] = start;
591 		(*argc)++;
592 	}
593 
594 	*argvp = argv;
595 	return 0;
596 }
597 
dm_set_stacking_limits(struct queue_limits * limits)598 static void dm_set_stacking_limits(struct queue_limits *limits)
599 {
600 	blk_set_stacking_limits(limits);
601 	limits->features |= BLK_FEAT_IO_STAT | BLK_FEAT_NOWAIT | BLK_FEAT_POLL;
602 }
603 
604 /*
605  * Impose necessary and sufficient conditions on a devices's table such
606  * that any incoming bio which respects its logical_block_size can be
607  * processed successfully.  If it falls across the boundary between
608  * two or more targets, the size of each piece it gets split into must
609  * be compatible with the logical_block_size of the target processing it.
610  */
validate_hardware_logical_block_alignment(struct dm_table * t,struct queue_limits * limits)611 static int validate_hardware_logical_block_alignment(struct dm_table *t,
612 						     struct queue_limits *limits)
613 {
614 	/*
615 	 * This function uses arithmetic modulo the logical_block_size
616 	 * (in units of 512-byte sectors).
617 	 */
618 	unsigned short device_logical_block_size_sects =
619 		limits->logical_block_size >> SECTOR_SHIFT;
620 
621 	/*
622 	 * Offset of the start of the next table entry, mod logical_block_size.
623 	 */
624 	unsigned short next_target_start = 0;
625 
626 	/*
627 	 * Given an aligned bio that extends beyond the end of a
628 	 * target, how many sectors must the next target handle?
629 	 */
630 	unsigned short remaining = 0;
631 
632 	struct dm_target *ti;
633 	struct queue_limits ti_limits;
634 	unsigned int i;
635 
636 	/*
637 	 * Check each entry in the table in turn.
638 	 */
639 	for (i = 0; i < t->num_targets; i++) {
640 		ti = dm_table_get_target(t, i);
641 
642 		dm_set_stacking_limits(&ti_limits);
643 
644 		/* combine all target devices' limits */
645 		if (ti->type->iterate_devices)
646 			ti->type->iterate_devices(ti, dm_set_device_limits,
647 						  &ti_limits);
648 
649 		/*
650 		 * If the remaining sectors fall entirely within this
651 		 * table entry are they compatible with its logical_block_size?
652 		 */
653 		if (remaining < ti->len &&
654 		    remaining & ((ti_limits.logical_block_size >>
655 				  SECTOR_SHIFT) - 1))
656 			break;	/* Error */
657 
658 		next_target_start =
659 		    (unsigned short) ((next_target_start + ti->len) &
660 				      (device_logical_block_size_sects - 1));
661 		remaining = next_target_start ?
662 		    device_logical_block_size_sects - next_target_start : 0;
663 	}
664 
665 	if (remaining) {
666 		DMERR("%s: table line %u (start sect %llu len %llu) "
667 		      "not aligned to h/w logical block size %u",
668 		      dm_device_name(t->md), i,
669 		      (unsigned long long) ti->begin,
670 		      (unsigned long long) ti->len,
671 		      limits->logical_block_size);
672 		return -EINVAL;
673 	}
674 
675 	return 0;
676 }
677 
dm_table_add_target(struct dm_table * t,const char * type,sector_t start,sector_t len,char * params)678 int dm_table_add_target(struct dm_table *t, const char *type,
679 			sector_t start, sector_t len, char *params)
680 {
681 	int r = -EINVAL, argc;
682 	char **argv;
683 	struct dm_target *ti;
684 
685 	if (t->singleton) {
686 		DMERR("%s: target type %s must appear alone in table",
687 		      dm_device_name(t->md), t->targets->type->name);
688 		return -EINVAL;
689 	}
690 
691 	BUG_ON(t->num_targets >= t->num_allocated);
692 
693 	ti = t->targets + t->num_targets;
694 	memset(ti, 0, sizeof(*ti));
695 
696 	if (!len) {
697 		DMERR("%s: zero-length target", dm_device_name(t->md));
698 		return -EINVAL;
699 	}
700 
701 	ti->type = dm_get_target_type(type);
702 	if (!ti->type) {
703 		DMERR("%s: %s: unknown target type", dm_device_name(t->md), type);
704 		return -EINVAL;
705 	}
706 
707 	if (dm_target_needs_singleton(ti->type)) {
708 		if (t->num_targets) {
709 			ti->error = "singleton target type must appear alone in table";
710 			goto bad;
711 		}
712 		t->singleton = true;
713 	}
714 
715 	if (dm_target_always_writeable(ti->type) &&
716 	    !(t->mode & BLK_OPEN_WRITE)) {
717 		ti->error = "target type may not be included in a read-only table";
718 		goto bad;
719 	}
720 
721 	if (t->immutable_target_type) {
722 		if (t->immutable_target_type != ti->type) {
723 			ti->error = "immutable target type cannot be mixed with other target types";
724 			goto bad;
725 		}
726 	} else if (dm_target_is_immutable(ti->type)) {
727 		if (t->num_targets) {
728 			ti->error = "immutable target type cannot be mixed with other target types";
729 			goto bad;
730 		}
731 		t->immutable_target_type = ti->type;
732 	}
733 
734 	ti->table = t;
735 	ti->begin = start;
736 	ti->len = len;
737 	ti->error = "Unknown error";
738 
739 	/*
740 	 * Does this target adjoin the previous one ?
741 	 */
742 	if (!adjoin(t, ti)) {
743 		ti->error = "Gap in table";
744 		goto bad;
745 	}
746 
747 	r = dm_split_args(&argc, &argv, params);
748 	if (r) {
749 		ti->error = "couldn't split parameters";
750 		goto bad;
751 	}
752 
753 	r = ti->type->ctr(ti, argc, argv);
754 	kfree(argv);
755 	if (r)
756 		goto bad;
757 
758 	t->highs[t->num_targets++] = ti->begin + ti->len - 1;
759 
760 	if (!ti->num_discard_bios && ti->discards_supported)
761 		DMWARN("%s: %s: ignoring discards_supported because num_discard_bios is zero.",
762 		       dm_device_name(t->md), type);
763 
764 	if (ti->limit_swap_bios && !static_key_enabled(&swap_bios_enabled.key))
765 		static_branch_enable(&swap_bios_enabled);
766 
767 	if (!ti->flush_bypasses_map)
768 		t->flush_bypasses_map = false;
769 
770 	return 0;
771 
772  bad:
773 	DMERR("%s: %s: %s (%pe)", dm_device_name(t->md), type, ti->error, ERR_PTR(r));
774 	dm_put_target_type(ti->type);
775 	return r;
776 }
777 
778 /*
779  * Target argument parsing helpers.
780  */
validate_next_arg(const struct dm_arg * arg,struct dm_arg_set * arg_set,unsigned int * value,char ** error,unsigned int grouped)781 static int validate_next_arg(const struct dm_arg *arg, struct dm_arg_set *arg_set,
782 			     unsigned int *value, char **error, unsigned int grouped)
783 {
784 	const char *arg_str = dm_shift_arg(arg_set);
785 	char dummy;
786 
787 	if (!arg_str ||
788 	    (sscanf(arg_str, "%u%c", value, &dummy) != 1) ||
789 	    (*value < arg->min) ||
790 	    (*value > arg->max) ||
791 	    (grouped && arg_set->argc < *value)) {
792 		*error = arg->error;
793 		return -EINVAL;
794 	}
795 
796 	return 0;
797 }
798 
dm_read_arg(const struct dm_arg * arg,struct dm_arg_set * arg_set,unsigned int * value,char ** error)799 int dm_read_arg(const struct dm_arg *arg, struct dm_arg_set *arg_set,
800 		unsigned int *value, char **error)
801 {
802 	return validate_next_arg(arg, arg_set, value, error, 0);
803 }
804 EXPORT_SYMBOL(dm_read_arg);
805 
dm_read_arg_group(const struct dm_arg * arg,struct dm_arg_set * arg_set,unsigned int * value,char ** error)806 int dm_read_arg_group(const struct dm_arg *arg, struct dm_arg_set *arg_set,
807 		      unsigned int *value, char **error)
808 {
809 	return validate_next_arg(arg, arg_set, value, error, 1);
810 }
811 EXPORT_SYMBOL(dm_read_arg_group);
812 
dm_shift_arg(struct dm_arg_set * as)813 const char *dm_shift_arg(struct dm_arg_set *as)
814 {
815 	char *r;
816 
817 	if (as->argc) {
818 		as->argc--;
819 		r = *as->argv;
820 		as->argv++;
821 		return r;
822 	}
823 
824 	return NULL;
825 }
826 EXPORT_SYMBOL(dm_shift_arg);
827 
dm_consume_args(struct dm_arg_set * as,unsigned int num_args)828 void dm_consume_args(struct dm_arg_set *as, unsigned int num_args)
829 {
830 	BUG_ON(as->argc < num_args);
831 	as->argc -= num_args;
832 	as->argv += num_args;
833 }
834 EXPORT_SYMBOL(dm_consume_args);
835 
__table_type_bio_based(enum dm_queue_mode table_type)836 static bool __table_type_bio_based(enum dm_queue_mode table_type)
837 {
838 	return (table_type == DM_TYPE_BIO_BASED ||
839 		table_type == DM_TYPE_DAX_BIO_BASED);
840 }
841 
__table_type_request_based(enum dm_queue_mode table_type)842 static bool __table_type_request_based(enum dm_queue_mode table_type)
843 {
844 	return table_type == DM_TYPE_REQUEST_BASED;
845 }
846 
dm_table_set_type(struct dm_table * t,enum dm_queue_mode type)847 void dm_table_set_type(struct dm_table *t, enum dm_queue_mode type)
848 {
849 	t->type = type;
850 }
851 EXPORT_SYMBOL_GPL(dm_table_set_type);
852 
853 /* 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)854 static int device_not_dax_capable(struct dm_target *ti, struct dm_dev *dev,
855 			sector_t start, sector_t len, void *data)
856 {
857 	if (dev->dax_dev)
858 		return false;
859 
860 	DMDEBUG("%pg: error: dax unsupported by block device", dev->bdev);
861 	return true;
862 }
863 
864 /* 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)865 static int device_not_dax_synchronous_capable(struct dm_target *ti, struct dm_dev *dev,
866 					      sector_t start, sector_t len, void *data)
867 {
868 	return !dev->dax_dev || !dax_synchronous(dev->dax_dev);
869 }
870 
dm_table_supports_dax(struct dm_table * t,iterate_devices_callout_fn iterate_fn)871 static bool dm_table_supports_dax(struct dm_table *t,
872 				  iterate_devices_callout_fn iterate_fn)
873 {
874 	/* Ensure that all targets support DAX. */
875 	for (unsigned int i = 0; i < t->num_targets; i++) {
876 		struct dm_target *ti = dm_table_get_target(t, i);
877 
878 		if (!ti->type->direct_access)
879 			return false;
880 
881 		if (dm_target_is_wildcard(ti->type) ||
882 		    !ti->type->iterate_devices ||
883 		    ti->type->iterate_devices(ti, iterate_fn, NULL))
884 			return false;
885 	}
886 
887 	return true;
888 }
889 
device_is_rq_stackable(struct dm_target * ti,struct dm_dev * dev,sector_t start,sector_t len,void * data)890 static int device_is_rq_stackable(struct dm_target *ti, struct dm_dev *dev,
891 				  sector_t start, sector_t len, void *data)
892 {
893 	struct block_device *bdev = dev->bdev;
894 	struct request_queue *q = bdev_get_queue(bdev);
895 
896 	/* request-based cannot stack on partitions! */
897 	if (bdev_is_partition(bdev))
898 		return false;
899 
900 	return queue_is_mq(q);
901 }
902 
dm_table_determine_type(struct dm_table * t)903 static int dm_table_determine_type(struct dm_table *t)
904 {
905 	unsigned int bio_based = 0, request_based = 0, hybrid = 0;
906 	struct dm_target *ti;
907 	struct list_head *devices = dm_table_get_devices(t);
908 	enum dm_queue_mode live_md_type = dm_get_md_type(t->md);
909 
910 	if (t->type != DM_TYPE_NONE) {
911 		/* target already set the table's type */
912 		if (t->type == DM_TYPE_BIO_BASED) {
913 			/* possibly upgrade to a variant of bio-based */
914 			goto verify_bio_based;
915 		}
916 		BUG_ON(t->type == DM_TYPE_DAX_BIO_BASED);
917 		goto verify_rq_based;
918 	}
919 
920 	for (unsigned int i = 0; i < t->num_targets; i++) {
921 		ti = dm_table_get_target(t, i);
922 		if (dm_target_hybrid(ti))
923 			hybrid = 1;
924 		else if (dm_target_request_based(ti))
925 			request_based = 1;
926 		else
927 			bio_based = 1;
928 
929 		if (bio_based && request_based) {
930 			DMERR("Inconsistent table: different target types can't be mixed up");
931 			return -EINVAL;
932 		}
933 	}
934 
935 	if (hybrid && !bio_based && !request_based) {
936 		/*
937 		 * The targets can work either way.
938 		 * Determine the type from the live device.
939 		 * Default to bio-based if device is new.
940 		 */
941 		if (__table_type_request_based(live_md_type))
942 			request_based = 1;
943 		else
944 			bio_based = 1;
945 	}
946 
947 	if (bio_based) {
948 verify_bio_based:
949 		/* We must use this table as bio-based */
950 		t->type = DM_TYPE_BIO_BASED;
951 		if (dm_table_supports_dax(t, device_not_dax_capable) ||
952 		    (list_empty(devices) && live_md_type == DM_TYPE_DAX_BIO_BASED)) {
953 			t->type = DM_TYPE_DAX_BIO_BASED;
954 		}
955 		return 0;
956 	}
957 
958 	BUG_ON(!request_based); /* No targets in this table */
959 
960 	t->type = DM_TYPE_REQUEST_BASED;
961 
962 verify_rq_based:
963 	/*
964 	 * Request-based dm supports only tables that have a single target now.
965 	 * To support multiple targets, request splitting support is needed,
966 	 * and that needs lots of changes in the block-layer.
967 	 * (e.g. request completion process for partial completion.)
968 	 */
969 	if (t->num_targets > 1) {
970 		DMERR("request-based DM doesn't support multiple targets");
971 		return -EINVAL;
972 	}
973 
974 	if (list_empty(devices)) {
975 		int srcu_idx;
976 		struct dm_table *live_table = dm_get_live_table(t->md, &srcu_idx);
977 
978 		/* inherit live table's type */
979 		if (live_table)
980 			t->type = live_table->type;
981 		dm_put_live_table(t->md, srcu_idx);
982 		return 0;
983 	}
984 
985 	ti = dm_table_get_immutable_target(t);
986 	if (!ti) {
987 		DMERR("table load rejected: immutable target is required");
988 		return -EINVAL;
989 	} else if (ti->max_io_len) {
990 		DMERR("table load rejected: immutable target that splits IO is not supported");
991 		return -EINVAL;
992 	}
993 
994 	/* Non-request-stackable devices can't be used for request-based dm */
995 	if (!ti->type->iterate_devices ||
996 	    !ti->type->iterate_devices(ti, device_is_rq_stackable, NULL)) {
997 		DMERR("table load rejected: including non-request-stackable devices");
998 		return -EINVAL;
999 	}
1000 
1001 	return 0;
1002 }
1003 
dm_table_get_type(struct dm_table * t)1004 enum dm_queue_mode dm_table_get_type(struct dm_table *t)
1005 {
1006 	return t->type;
1007 }
1008 
dm_table_get_immutable_target_type(struct dm_table * t)1009 struct target_type *dm_table_get_immutable_target_type(struct dm_table *t)
1010 {
1011 	return t->immutable_target_type;
1012 }
1013 
dm_table_get_immutable_target(struct dm_table * t)1014 struct dm_target *dm_table_get_immutable_target(struct dm_table *t)
1015 {
1016 	/* Immutable target is implicitly a singleton */
1017 	if (t->num_targets > 1 ||
1018 	    !dm_target_is_immutable(t->targets[0].type))
1019 		return NULL;
1020 
1021 	return t->targets;
1022 }
1023 
dm_table_get_wildcard_target(struct dm_table * t)1024 struct dm_target *dm_table_get_wildcard_target(struct dm_table *t)
1025 {
1026 	for (unsigned int i = 0; i < t->num_targets; i++) {
1027 		struct dm_target *ti = dm_table_get_target(t, i);
1028 
1029 		if (dm_target_is_wildcard(ti->type))
1030 			return ti;
1031 	}
1032 
1033 	return NULL;
1034 }
1035 
dm_table_request_based(struct dm_table * t)1036 bool dm_table_request_based(struct dm_table *t)
1037 {
1038 	return __table_type_request_based(dm_table_get_type(t));
1039 }
1040 
dm_table_alloc_md_mempools(struct dm_table * t,struct mapped_device * md)1041 static int dm_table_alloc_md_mempools(struct dm_table *t, struct mapped_device *md)
1042 {
1043 	enum dm_queue_mode type = dm_table_get_type(t);
1044 	unsigned int per_io_data_size = 0, front_pad, io_front_pad;
1045 	unsigned int min_pool_size = 0, pool_size;
1046 	struct dm_md_mempools *pools;
1047 	unsigned int bioset_flags = 0;
1048 	bool mempool_needs_integrity = t->integrity_supported;
1049 
1050 	if (unlikely(type == DM_TYPE_NONE)) {
1051 		DMERR("no table type is set, can't allocate mempools");
1052 		return -EINVAL;
1053 	}
1054 
1055 	pools = kzalloc_node(sizeof(*pools), GFP_KERNEL, md->numa_node_id);
1056 	if (!pools)
1057 		return -ENOMEM;
1058 
1059 	if (type == DM_TYPE_REQUEST_BASED) {
1060 		pool_size = dm_get_reserved_rq_based_ios();
1061 		front_pad = offsetof(struct dm_rq_clone_bio_info, clone);
1062 		goto init_bs;
1063 	}
1064 
1065 	if (md->queue->limits.features & BLK_FEAT_POLL)
1066 		bioset_flags |= BIOSET_PERCPU_CACHE;
1067 
1068 	for (unsigned int i = 0; i < t->num_targets; i++) {
1069 		struct dm_target *ti = dm_table_get_target(t, i);
1070 
1071 		per_io_data_size = max(per_io_data_size, ti->per_io_data_size);
1072 		min_pool_size = max(min_pool_size, ti->num_flush_bios);
1073 
1074 		mempool_needs_integrity |= ti->mempool_needs_integrity;
1075 	}
1076 	pool_size = max(dm_get_reserved_bio_based_ios(), min_pool_size);
1077 	front_pad = roundup(per_io_data_size,
1078 		__alignof__(struct dm_target_io)) + DM_TARGET_IO_BIO_OFFSET;
1079 
1080 	io_front_pad = roundup(per_io_data_size,
1081 		__alignof__(struct dm_io)) + DM_IO_BIO_OFFSET;
1082 	if (bioset_init(&pools->io_bs, pool_size, io_front_pad, bioset_flags))
1083 		goto out_free_pools;
1084 init_bs:
1085 	if (bioset_init(&pools->bs, pool_size, front_pad, 0))
1086 		goto out_free_pools;
1087 
1088 	t->mempools = pools;
1089 	return 0;
1090 
1091 out_free_pools:
1092 	dm_free_md_mempools(pools);
1093 	return -ENOMEM;
1094 }
1095 
setup_indexes(struct dm_table * t)1096 static int setup_indexes(struct dm_table *t)
1097 {
1098 	int i;
1099 	unsigned int total = 0;
1100 	sector_t *indexes;
1101 
1102 	/* allocate the space for *all* the indexes */
1103 	for (i = t->depth - 2; i >= 0; i--) {
1104 		t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE);
1105 		total += t->counts[i];
1106 	}
1107 
1108 	indexes = kvcalloc(total, NODE_SIZE, GFP_KERNEL);
1109 	if (!indexes)
1110 		return -ENOMEM;
1111 
1112 	/* set up internal nodes, bottom-up */
1113 	for (i = t->depth - 2; i >= 0; i--) {
1114 		t->index[i] = indexes;
1115 		indexes += (KEYS_PER_NODE * t->counts[i]);
1116 		setup_btree_index(i, t);
1117 	}
1118 
1119 	return 0;
1120 }
1121 
1122 /*
1123  * Builds the btree to index the map.
1124  */
dm_table_build_index(struct dm_table * t)1125 static int dm_table_build_index(struct dm_table *t)
1126 {
1127 	int r = 0;
1128 	unsigned int leaf_nodes;
1129 
1130 	/* how many indexes will the btree have ? */
1131 	leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE);
1132 	t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE);
1133 
1134 	/* leaf layer has already been set up */
1135 	t->counts[t->depth - 1] = leaf_nodes;
1136 	t->index[t->depth - 1] = t->highs;
1137 
1138 	if (t->depth >= 2)
1139 		r = setup_indexes(t);
1140 
1141 	return r;
1142 }
1143 
1144 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
1145 
1146 struct dm_crypto_profile {
1147 	struct blk_crypto_profile profile;
1148 	struct mapped_device *md;
1149 };
1150 
dm_keyslot_evict_callback(struct dm_target * ti,struct dm_dev * dev,sector_t start,sector_t len,void * data)1151 static int dm_keyslot_evict_callback(struct dm_target *ti, struct dm_dev *dev,
1152 				     sector_t start, sector_t len, void *data)
1153 {
1154 	const struct blk_crypto_key *key = data;
1155 
1156 	blk_crypto_evict_key(dev->bdev, key);
1157 	return 0;
1158 }
1159 
1160 /*
1161  * When an inline encryption key is evicted from a device-mapper device, evict
1162  * it from all the underlying devices.
1163  */
dm_keyslot_evict(struct blk_crypto_profile * profile,const struct blk_crypto_key * key,unsigned int slot)1164 static int dm_keyslot_evict(struct blk_crypto_profile *profile,
1165 			    const struct blk_crypto_key *key, unsigned int slot)
1166 {
1167 	struct mapped_device *md =
1168 		container_of(profile, struct dm_crypto_profile, profile)->md;
1169 	struct dm_table *t;
1170 	int srcu_idx;
1171 
1172 	t = dm_get_live_table(md, &srcu_idx);
1173 	if (!t)
1174 		return 0;
1175 
1176 	for (unsigned int i = 0; i < t->num_targets; i++) {
1177 		struct dm_target *ti = dm_table_get_target(t, i);
1178 
1179 		if (!ti->type->iterate_devices)
1180 			continue;
1181 		ti->type->iterate_devices(ti, dm_keyslot_evict_callback,
1182 					  (void *)key);
1183 	}
1184 
1185 	dm_put_live_table(md, srcu_idx);
1186 	return 0;
1187 }
1188 
1189 static int
device_intersect_crypto_capabilities(struct dm_target * ti,struct dm_dev * dev,sector_t start,sector_t len,void * data)1190 device_intersect_crypto_capabilities(struct dm_target *ti, struct dm_dev *dev,
1191 				     sector_t start, sector_t len, void *data)
1192 {
1193 	struct blk_crypto_profile *parent = data;
1194 	struct blk_crypto_profile *child =
1195 		bdev_get_queue(dev->bdev)->crypto_profile;
1196 
1197 	blk_crypto_intersect_capabilities(parent, child);
1198 	return 0;
1199 }
1200 
dm_destroy_crypto_profile(struct blk_crypto_profile * profile)1201 void dm_destroy_crypto_profile(struct blk_crypto_profile *profile)
1202 {
1203 	struct dm_crypto_profile *dmcp = container_of(profile,
1204 						      struct dm_crypto_profile,
1205 						      profile);
1206 
1207 	if (!profile)
1208 		return;
1209 
1210 	blk_crypto_profile_destroy(profile);
1211 	kfree(dmcp);
1212 }
1213 
dm_table_destroy_crypto_profile(struct dm_table * t)1214 static void dm_table_destroy_crypto_profile(struct dm_table *t)
1215 {
1216 	dm_destroy_crypto_profile(t->crypto_profile);
1217 	t->crypto_profile = NULL;
1218 }
1219 
1220 /*
1221  * Constructs and initializes t->crypto_profile with a crypto profile that
1222  * represents the common set of crypto capabilities of the devices described by
1223  * the dm_table.  However, if the constructed crypto profile doesn't support all
1224  * crypto capabilities that are supported by the current mapped_device, it
1225  * returns an error instead, since we don't support removing crypto capabilities
1226  * on table changes.  Finally, if the constructed crypto profile is "empty" (has
1227  * no crypto capabilities at all), it just sets t->crypto_profile to NULL.
1228  */
dm_table_construct_crypto_profile(struct dm_table * t)1229 static int dm_table_construct_crypto_profile(struct dm_table *t)
1230 {
1231 	struct dm_crypto_profile *dmcp;
1232 	struct blk_crypto_profile *profile;
1233 	unsigned int i;
1234 	bool empty_profile = true;
1235 
1236 	dmcp = kmalloc(sizeof(*dmcp), GFP_KERNEL);
1237 	if (!dmcp)
1238 		return -ENOMEM;
1239 	dmcp->md = t->md;
1240 
1241 	profile = &dmcp->profile;
1242 	blk_crypto_profile_init(profile, 0);
1243 	profile->ll_ops.keyslot_evict = dm_keyslot_evict;
1244 	profile->max_dun_bytes_supported = UINT_MAX;
1245 	memset(profile->modes_supported, 0xFF,
1246 	       sizeof(profile->modes_supported));
1247 	profile->key_types_supported = ~0;
1248 
1249 	for (i = 0; i < t->num_targets; i++) {
1250 		struct dm_target *ti = dm_table_get_target(t, i);
1251 
1252 		if (!dm_target_passes_crypto(ti->type)) {
1253 			blk_crypto_intersect_capabilities(profile, NULL);
1254 			break;
1255 		}
1256 		if (!ti->type->iterate_devices)
1257 			continue;
1258 		ti->type->iterate_devices(ti,
1259 					  device_intersect_crypto_capabilities,
1260 					  profile);
1261 	}
1262 
1263 	if (t->md->queue &&
1264 	    !blk_crypto_has_capabilities(profile,
1265 					 t->md->queue->crypto_profile)) {
1266 		DMERR("Inline encryption capabilities of new DM table were more restrictive than the old table's. This is not supported!");
1267 		dm_destroy_crypto_profile(profile);
1268 		return -EINVAL;
1269 	}
1270 
1271 	/*
1272 	 * If the new profile doesn't actually support any crypto capabilities,
1273 	 * we may as well represent it with a NULL profile.
1274 	 */
1275 	for (i = 0; i < ARRAY_SIZE(profile->modes_supported); i++) {
1276 		if (profile->modes_supported[i]) {
1277 			empty_profile = false;
1278 			break;
1279 		}
1280 	}
1281 
1282 	if (empty_profile) {
1283 		dm_destroy_crypto_profile(profile);
1284 		profile = NULL;
1285 	}
1286 
1287 	/*
1288 	 * t->crypto_profile is only set temporarily while the table is being
1289 	 * set up, and it gets set to NULL after the profile has been
1290 	 * transferred to the request_queue.
1291 	 */
1292 	t->crypto_profile = profile;
1293 
1294 	return 0;
1295 }
1296 
dm_update_crypto_profile(struct request_queue * q,struct dm_table * t)1297 static void dm_update_crypto_profile(struct request_queue *q,
1298 				     struct dm_table *t)
1299 {
1300 	if (!t->crypto_profile)
1301 		return;
1302 
1303 	/* Make the crypto profile less restrictive. */
1304 	if (!q->crypto_profile) {
1305 		blk_crypto_register(t->crypto_profile, q);
1306 	} else {
1307 		blk_crypto_update_capabilities(q->crypto_profile,
1308 					       t->crypto_profile);
1309 		dm_destroy_crypto_profile(t->crypto_profile);
1310 	}
1311 	t->crypto_profile = NULL;
1312 }
1313 
1314 #else /* CONFIG_BLK_INLINE_ENCRYPTION */
1315 
dm_table_construct_crypto_profile(struct dm_table * t)1316 static int dm_table_construct_crypto_profile(struct dm_table *t)
1317 {
1318 	return 0;
1319 }
1320 
dm_destroy_crypto_profile(struct blk_crypto_profile * profile)1321 void dm_destroy_crypto_profile(struct blk_crypto_profile *profile)
1322 {
1323 }
1324 
dm_table_destroy_crypto_profile(struct dm_table * t)1325 static void dm_table_destroy_crypto_profile(struct dm_table *t)
1326 {
1327 }
1328 
dm_update_crypto_profile(struct request_queue * q,struct dm_table * t)1329 static void dm_update_crypto_profile(struct request_queue *q,
1330 				     struct dm_table *t)
1331 {
1332 }
1333 
1334 #endif /* !CONFIG_BLK_INLINE_ENCRYPTION */
1335 
1336 /*
1337  * Prepares the table for use by building the indices,
1338  * setting the type, and allocating mempools.
1339  */
dm_table_complete(struct dm_table * t)1340 int dm_table_complete(struct dm_table *t)
1341 {
1342 	int r;
1343 
1344 	r = dm_table_determine_type(t);
1345 	if (r) {
1346 		DMERR("unable to determine table type");
1347 		return r;
1348 	}
1349 
1350 	r = dm_table_build_index(t);
1351 	if (r) {
1352 		DMERR("unable to build btrees");
1353 		return r;
1354 	}
1355 
1356 	r = dm_table_construct_crypto_profile(t);
1357 	if (r) {
1358 		DMERR("could not construct crypto profile.");
1359 		return r;
1360 	}
1361 
1362 	r = dm_table_alloc_md_mempools(t, t->md);
1363 	if (r)
1364 		DMERR("unable to allocate mempools");
1365 
1366 	return r;
1367 }
1368 
1369 static DEFINE_MUTEX(_event_lock);
dm_table_event_callback(struct dm_table * t,void (* fn)(void *),void * context)1370 void dm_table_event_callback(struct dm_table *t,
1371 			     void (*fn)(void *), void *context)
1372 {
1373 	mutex_lock(&_event_lock);
1374 	t->event_fn = fn;
1375 	t->event_context = context;
1376 	mutex_unlock(&_event_lock);
1377 }
1378 
dm_table_event(struct dm_table * t)1379 void dm_table_event(struct dm_table *t)
1380 {
1381 	mutex_lock(&_event_lock);
1382 	if (t->event_fn)
1383 		t->event_fn(t->event_context);
1384 	mutex_unlock(&_event_lock);
1385 }
1386 EXPORT_SYMBOL(dm_table_event);
1387 
dm_table_get_size(struct dm_table * t)1388 inline sector_t dm_table_get_size(struct dm_table *t)
1389 {
1390 	return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0;
1391 }
1392 EXPORT_SYMBOL(dm_table_get_size);
1393 
1394 /*
1395  * Search the btree for the correct target.
1396  *
1397  * Caller should check returned pointer for NULL
1398  * to trap I/O beyond end of device.
1399  */
dm_table_find_target(struct dm_table * t,sector_t sector)1400 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
1401 {
1402 	unsigned int l, n = 0, k = 0;
1403 	sector_t *node;
1404 
1405 	if (unlikely(sector >= dm_table_get_size(t)))
1406 		return NULL;
1407 
1408 	for (l = 0; l < t->depth; l++) {
1409 		n = get_child(n, k);
1410 		node = get_node(t, l, n);
1411 
1412 		for (k = 0; k < KEYS_PER_NODE; k++)
1413 			if (node[k] >= sector)
1414 				break;
1415 	}
1416 
1417 	return &t->targets[(KEYS_PER_NODE * n) + k];
1418 }
1419 
1420 /*
1421  * type->iterate_devices() should be called when the sanity check needs to
1422  * iterate and check all underlying data devices. iterate_devices() will
1423  * iterate all underlying data devices until it encounters a non-zero return
1424  * code, returned by whether the input iterate_devices_callout_fn, or
1425  * iterate_devices() itself internally.
1426  *
1427  * For some target type (e.g. dm-stripe), one call of iterate_devices() may
1428  * iterate multiple underlying devices internally, in which case a non-zero
1429  * return code returned by iterate_devices_callout_fn will stop the iteration
1430  * in advance.
1431  *
1432  * Cases requiring _any_ underlying device supporting some kind of attribute,
1433  * should use the iteration structure like dm_table_any_dev_attr(), or call
1434  * it directly. @func should handle semantics of positive examples, e.g.
1435  * capable of something.
1436  *
1437  * Cases requiring _all_ underlying devices supporting some kind of attribute,
1438  * should use the iteration structure like dm_table_supports_nowait() or
1439  * dm_table_supports_discards(). Or introduce dm_table_all_devs_attr() that
1440  * uses an @anti_func that handle semantics of counter examples, e.g. not
1441  * capable of something. So: return !dm_table_any_dev_attr(t, anti_func, data);
1442  */
dm_table_any_dev_attr(struct dm_table * t,iterate_devices_callout_fn func,void * data)1443 static bool dm_table_any_dev_attr(struct dm_table *t,
1444 				  iterate_devices_callout_fn func, void *data)
1445 {
1446 	for (unsigned int i = 0; i < t->num_targets; i++) {
1447 		struct dm_target *ti = dm_table_get_target(t, i);
1448 
1449 		if (ti->type->iterate_devices &&
1450 		    ti->type->iterate_devices(ti, func, data))
1451 			return true;
1452 	}
1453 
1454 	return false;
1455 }
1456 
count_device(struct dm_target * ti,struct dm_dev * dev,sector_t start,sector_t len,void * data)1457 static int count_device(struct dm_target *ti, struct dm_dev *dev,
1458 			sector_t start, sector_t len, void *data)
1459 {
1460 	unsigned int *num_devices = data;
1461 
1462 	(*num_devices)++;
1463 
1464 	return 0;
1465 }
1466 
1467 /*
1468  * Check whether a table has no data devices attached using each
1469  * target's iterate_devices method.
1470  * Returns false if the result is unknown because a target doesn't
1471  * support iterate_devices.
1472  */
dm_table_has_no_data_devices(struct dm_table * t)1473 bool dm_table_has_no_data_devices(struct dm_table *t)
1474 {
1475 	for (unsigned int i = 0; i < t->num_targets; i++) {
1476 		struct dm_target *ti = dm_table_get_target(t, i);
1477 		unsigned int num_devices = 0;
1478 
1479 		if (!ti->type->iterate_devices)
1480 			return false;
1481 
1482 		ti->type->iterate_devices(ti, count_device, &num_devices);
1483 		if (num_devices)
1484 			return false;
1485 	}
1486 
1487 	return true;
1488 }
1489 
device_not_zoned(struct dm_target * ti,struct dm_dev * dev,sector_t start,sector_t len,void * data)1490 static int device_not_zoned(struct dm_target *ti, struct dm_dev *dev,
1491 			    sector_t start, sector_t len, void *data)
1492 {
1493 	bool *zoned = data;
1494 
1495 	return bdev_is_zoned(dev->bdev) != *zoned;
1496 }
1497 
device_is_zoned_model(struct dm_target * ti,struct dm_dev * dev,sector_t start,sector_t len,void * data)1498 static int device_is_zoned_model(struct dm_target *ti, struct dm_dev *dev,
1499 				 sector_t start, sector_t len, void *data)
1500 {
1501 	return bdev_is_zoned(dev->bdev);
1502 }
1503 
1504 /*
1505  * Check the device zoned model based on the target feature flag. If the target
1506  * has the DM_TARGET_ZONED_HM feature flag set, host-managed zoned devices are
1507  * also accepted but all devices must have the same zoned model. If the target
1508  * has the DM_TARGET_MIXED_ZONED_MODEL feature set, the devices can have any
1509  * zoned model with all zoned devices having the same zone size.
1510  */
dm_table_supports_zoned(struct dm_table * t,bool zoned)1511 static bool dm_table_supports_zoned(struct dm_table *t, bool zoned)
1512 {
1513 	for (unsigned int i = 0; i < t->num_targets; i++) {
1514 		struct dm_target *ti = dm_table_get_target(t, i);
1515 
1516 		/*
1517 		 * For the wildcard target (dm-error), if we do not have a
1518 		 * backing device, we must always return false. If we have a
1519 		 * backing device, the result must depend on checking zoned
1520 		 * model, like for any other target. So for this, check directly
1521 		 * if the target backing device is zoned as we get "false" when
1522 		 * dm-error was set without a backing device.
1523 		 */
1524 		if (dm_target_is_wildcard(ti->type) &&
1525 		    !ti->type->iterate_devices(ti, device_is_zoned_model, NULL))
1526 			return false;
1527 
1528 		if (dm_target_supports_zoned_hm(ti->type)) {
1529 			if (!ti->type->iterate_devices ||
1530 			    ti->type->iterate_devices(ti, device_not_zoned,
1531 						      &zoned))
1532 				return false;
1533 		} else if (!dm_target_supports_mixed_zoned_model(ti->type)) {
1534 			if (zoned)
1535 				return false;
1536 		}
1537 	}
1538 
1539 	return true;
1540 }
1541 
device_not_matches_zone_sectors(struct dm_target * ti,struct dm_dev * dev,sector_t start,sector_t len,void * data)1542 static int device_not_matches_zone_sectors(struct dm_target *ti, struct dm_dev *dev,
1543 					   sector_t start, sector_t len, void *data)
1544 {
1545 	unsigned int *zone_sectors = data;
1546 
1547 	if (!bdev_is_zoned(dev->bdev))
1548 		return 0;
1549 	return bdev_zone_sectors(dev->bdev) != *zone_sectors;
1550 }
1551 
1552 /*
1553  * Check consistency of zoned model and zone sectors across all targets. For
1554  * zone sectors, if the destination device is a zoned block device, it shall
1555  * have the specified zone_sectors.
1556  */
validate_hardware_zoned(struct dm_table * t,bool zoned,unsigned int zone_sectors)1557 static int validate_hardware_zoned(struct dm_table *t, bool zoned,
1558 				   unsigned int zone_sectors)
1559 {
1560 	if (!zoned)
1561 		return 0;
1562 
1563 	if (!dm_table_supports_zoned(t, zoned)) {
1564 		DMERR("%s: zoned model is not consistent across all devices",
1565 		      dm_device_name(t->md));
1566 		return -EINVAL;
1567 	}
1568 
1569 	/* Check zone size validity and compatibility */
1570 	if (!zone_sectors || !is_power_of_2(zone_sectors))
1571 		return -EINVAL;
1572 
1573 	if (dm_table_any_dev_attr(t, device_not_matches_zone_sectors, &zone_sectors)) {
1574 		DMERR("%s: zone sectors is not consistent across all zoned devices",
1575 		      dm_device_name(t->md));
1576 		return -EINVAL;
1577 	}
1578 
1579 	return 0;
1580 }
1581 
1582 /*
1583  * Establish the new table's queue_limits and validate them.
1584  */
dm_calculate_queue_limits(struct dm_table * t,struct queue_limits * limits)1585 int dm_calculate_queue_limits(struct dm_table *t,
1586 			      struct queue_limits *limits)
1587 {
1588 	struct queue_limits ti_limits;
1589 	unsigned int zone_sectors = 0;
1590 	bool zoned = false;
1591 
1592 	dm_set_stacking_limits(limits);
1593 
1594 	t->integrity_supported = true;
1595 	for (unsigned int i = 0; i < t->num_targets; i++) {
1596 		struct dm_target *ti = dm_table_get_target(t, i);
1597 
1598 		if (!dm_target_passes_integrity(ti->type))
1599 			t->integrity_supported = false;
1600 	}
1601 
1602 	for (unsigned int i = 0; i < t->num_targets; i++) {
1603 		struct dm_target *ti = dm_table_get_target(t, i);
1604 
1605 		dm_set_stacking_limits(&ti_limits);
1606 
1607 		if (!ti->type->iterate_devices) {
1608 			/* Set I/O hints portion of queue limits */
1609 			if (ti->type->io_hints)
1610 				ti->type->io_hints(ti, &ti_limits);
1611 			goto combine_limits;
1612 		}
1613 
1614 		/*
1615 		 * Combine queue limits of all the devices this target uses.
1616 		 */
1617 		ti->type->iterate_devices(ti, dm_set_device_limits,
1618 					  &ti_limits);
1619 
1620 		if (!zoned && (ti_limits.features & BLK_FEAT_ZONED)) {
1621 			/*
1622 			 * After stacking all limits, validate all devices
1623 			 * in table support this zoned model and zone sectors.
1624 			 */
1625 			zoned = (ti_limits.features & BLK_FEAT_ZONED);
1626 			zone_sectors = ti_limits.chunk_sectors;
1627 		}
1628 
1629 		/* Set I/O hints portion of queue limits */
1630 		if (ti->type->io_hints)
1631 			ti->type->io_hints(ti, &ti_limits);
1632 
1633 		/*
1634 		 * Check each device area is consistent with the target's
1635 		 * overall queue limits.
1636 		 */
1637 		if (ti->type->iterate_devices(ti, device_area_is_invalid,
1638 					      &ti_limits))
1639 			return -EINVAL;
1640 
1641 combine_limits:
1642 		/*
1643 		 * Merge this target's queue limits into the overall limits
1644 		 * for the table.
1645 		 */
1646 		if (blk_stack_limits(limits, &ti_limits, 0) < 0)
1647 			DMWARN("%s: adding target device (start sect %llu len %llu) "
1648 			       "caused an alignment inconsistency",
1649 			       dm_device_name(t->md),
1650 			       (unsigned long long) ti->begin,
1651 			       (unsigned long long) ti->len);
1652 
1653 		if (t->integrity_supported ||
1654 		    dm_target_has_integrity(ti->type)) {
1655 			if (!queue_limits_stack_integrity(limits, &ti_limits)) {
1656 				DMWARN("%s: adding target device (start sect %llu len %llu) "
1657 				       "disabled integrity support due to incompatibility",
1658 				       dm_device_name(t->md),
1659 				       (unsigned long long) ti->begin,
1660 				       (unsigned long long) ti->len);
1661 				t->integrity_supported = false;
1662 			}
1663 		}
1664 	}
1665 
1666 	/*
1667 	 * Verify that the zoned model and zone sectors, as determined before
1668 	 * any .io_hints override, are the same across all devices in the table.
1669 	 * - this is especially relevant if .io_hints is emulating a disk-managed
1670 	 *   zoned model on host-managed zoned block devices.
1671 	 * BUT...
1672 	 */
1673 	if (limits->features & BLK_FEAT_ZONED) {
1674 		/*
1675 		 * ...IF the above limits stacking determined a zoned model
1676 		 * validate that all of the table's devices conform to it.
1677 		 */
1678 		zoned = limits->features & BLK_FEAT_ZONED;
1679 		zone_sectors = limits->chunk_sectors;
1680 	}
1681 	if (validate_hardware_zoned(t, zoned, zone_sectors))
1682 		return -EINVAL;
1683 
1684 	return validate_hardware_logical_block_alignment(t, limits);
1685 }
1686 
1687 /*
1688  * Check if a target requires flush support even if none of the underlying
1689  * devices need it (e.g. to persist target-specific metadata).
1690  */
dm_table_supports_flush(struct dm_table * t)1691 static bool dm_table_supports_flush(struct dm_table *t)
1692 {
1693 	for (unsigned int i = 0; i < t->num_targets; i++) {
1694 		struct dm_target *ti = dm_table_get_target(t, i);
1695 
1696 		if (ti->num_flush_bios && ti->flush_supported)
1697 			return true;
1698 	}
1699 
1700 	return false;
1701 }
1702 
device_dax_write_cache_enabled(struct dm_target * ti,struct dm_dev * dev,sector_t start,sector_t len,void * data)1703 static int device_dax_write_cache_enabled(struct dm_target *ti,
1704 					  struct dm_dev *dev, sector_t start,
1705 					  sector_t len, void *data)
1706 {
1707 	struct dax_device *dax_dev = dev->dax_dev;
1708 
1709 	if (!dax_dev)
1710 		return false;
1711 
1712 	if (dax_write_cache_enabled(dax_dev))
1713 		return true;
1714 	return false;
1715 }
1716 
device_not_write_zeroes_capable(struct dm_target * ti,struct dm_dev * dev,sector_t start,sector_t len,void * data)1717 static int device_not_write_zeroes_capable(struct dm_target *ti, struct dm_dev *dev,
1718 					   sector_t start, sector_t len, void *data)
1719 {
1720 	struct request_queue *q = bdev_get_queue(dev->bdev);
1721 
1722 	return !q->limits.max_write_zeroes_sectors;
1723 }
1724 
dm_table_supports_write_zeroes(struct dm_table * t)1725 static bool dm_table_supports_write_zeroes(struct dm_table *t)
1726 {
1727 	for (unsigned int i = 0; i < t->num_targets; i++) {
1728 		struct dm_target *ti = dm_table_get_target(t, i);
1729 
1730 		if (!ti->num_write_zeroes_bios)
1731 			return false;
1732 
1733 		if (!ti->type->iterate_devices ||
1734 		    ti->type->iterate_devices(ti, device_not_write_zeroes_capable, NULL))
1735 			return false;
1736 	}
1737 
1738 	return true;
1739 }
1740 
dm_table_supports_nowait(struct dm_table * t)1741 static bool dm_table_supports_nowait(struct dm_table *t)
1742 {
1743 	for (unsigned int i = 0; i < t->num_targets; i++) {
1744 		struct dm_target *ti = dm_table_get_target(t, i);
1745 
1746 		if (!dm_target_supports_nowait(ti->type))
1747 			return false;
1748 	}
1749 
1750 	return true;
1751 }
1752 
device_not_discard_capable(struct dm_target * ti,struct dm_dev * dev,sector_t start,sector_t len,void * data)1753 static int device_not_discard_capable(struct dm_target *ti, struct dm_dev *dev,
1754 				      sector_t start, sector_t len, void *data)
1755 {
1756 	return !bdev_max_discard_sectors(dev->bdev);
1757 }
1758 
dm_table_supports_discards(struct dm_table * t)1759 static bool dm_table_supports_discards(struct dm_table *t)
1760 {
1761 	for (unsigned int i = 0; i < t->num_targets; i++) {
1762 		struct dm_target *ti = dm_table_get_target(t, i);
1763 
1764 		if (!ti->num_discard_bios)
1765 			return false;
1766 
1767 		/*
1768 		 * Either the target provides discard support (as implied by setting
1769 		 * 'discards_supported') or it relies on _all_ data devices having
1770 		 * discard support.
1771 		 */
1772 		if (!ti->discards_supported &&
1773 		    (!ti->type->iterate_devices ||
1774 		     ti->type->iterate_devices(ti, device_not_discard_capable, NULL)))
1775 			return false;
1776 	}
1777 
1778 	return true;
1779 }
1780 
device_not_secure_erase_capable(struct dm_target * ti,struct dm_dev * dev,sector_t start,sector_t len,void * data)1781 static int device_not_secure_erase_capable(struct dm_target *ti,
1782 					   struct dm_dev *dev, sector_t start,
1783 					   sector_t len, void *data)
1784 {
1785 	return !bdev_max_secure_erase_sectors(dev->bdev);
1786 }
1787 
dm_table_supports_secure_erase(struct dm_table * t)1788 static bool dm_table_supports_secure_erase(struct dm_table *t)
1789 {
1790 	for (unsigned int i = 0; i < t->num_targets; i++) {
1791 		struct dm_target *ti = dm_table_get_target(t, i);
1792 
1793 		if (!ti->num_secure_erase_bios)
1794 			return false;
1795 
1796 		if (!ti->type->iterate_devices ||
1797 		    ti->type->iterate_devices(ti, device_not_secure_erase_capable, NULL))
1798 			return false;
1799 	}
1800 
1801 	return true;
1802 }
1803 
device_not_atomic_write_capable(struct dm_target * ti,struct dm_dev * dev,sector_t start,sector_t len,void * data)1804 static int device_not_atomic_write_capable(struct dm_target *ti,
1805 			struct dm_dev *dev, sector_t start,
1806 			sector_t len, void *data)
1807 {
1808 	return !bdev_can_atomic_write(dev->bdev);
1809 }
1810 
dm_table_supports_atomic_writes(struct dm_table * t)1811 static bool dm_table_supports_atomic_writes(struct dm_table *t)
1812 {
1813 	for (unsigned int i = 0; i < t->num_targets; i++) {
1814 		struct dm_target *ti = dm_table_get_target(t, i);
1815 
1816 		if (!dm_target_supports_atomic_writes(ti->type))
1817 			return false;
1818 
1819 		if (!ti->type->iterate_devices)
1820 			return false;
1821 
1822 		if (ti->type->iterate_devices(ti,
1823 			device_not_atomic_write_capable, NULL)) {
1824 			return false;
1825 		}
1826 	}
1827 	return true;
1828 }
1829 
dm_table_set_restrictions(struct dm_table * t,struct request_queue * q,struct queue_limits * limits)1830 int dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
1831 			      struct queue_limits *limits)
1832 {
1833 	int r;
1834 
1835 	if (!dm_table_supports_nowait(t))
1836 		limits->features &= ~BLK_FEAT_NOWAIT;
1837 
1838 	/*
1839 	 * The current polling impementation does not support request based
1840 	 * stacking.
1841 	 */
1842 	if (!__table_type_bio_based(t->type))
1843 		limits->features &= ~BLK_FEAT_POLL;
1844 
1845 	if (!dm_table_supports_discards(t)) {
1846 		limits->max_hw_discard_sectors = 0;
1847 		limits->discard_granularity = 0;
1848 		limits->discard_alignment = 0;
1849 	}
1850 
1851 	if (!dm_table_supports_write_zeroes(t))
1852 		limits->max_write_zeroes_sectors = 0;
1853 
1854 	if (!dm_table_supports_secure_erase(t))
1855 		limits->max_secure_erase_sectors = 0;
1856 
1857 	if (dm_table_supports_flush(t))
1858 		limits->features |= BLK_FEAT_WRITE_CACHE | BLK_FEAT_FUA;
1859 
1860 	if (dm_table_supports_dax(t, device_not_dax_capable)) {
1861 		limits->features |= BLK_FEAT_DAX;
1862 		if (dm_table_supports_dax(t, device_not_dax_synchronous_capable))
1863 			set_dax_synchronous(t->md->dax_dev);
1864 	} else
1865 		limits->features &= ~BLK_FEAT_DAX;
1866 
1867 	if (dm_table_any_dev_attr(t, device_dax_write_cache_enabled, NULL))
1868 		dax_write_cache(t->md->dax_dev, true);
1869 
1870 	/* For a zoned table, setup the zone related queue attributes. */
1871 	if (IS_ENABLED(CONFIG_BLK_DEV_ZONED) &&
1872 	    (limits->features & BLK_FEAT_ZONED)) {
1873 		r = dm_set_zones_restrictions(t, q, limits);
1874 		if (r)
1875 			return r;
1876 	}
1877 
1878 	if (dm_table_supports_atomic_writes(t))
1879 		limits->features |= BLK_FEAT_ATOMIC_WRITES;
1880 
1881 	r = queue_limits_set(q, limits);
1882 	if (r)
1883 		return r;
1884 
1885 	/*
1886 	 * Now that the limits are set, check the zones mapped by the table
1887 	 * and setup the resources for zone append emulation if necessary.
1888 	 */
1889 	if (IS_ENABLED(CONFIG_BLK_DEV_ZONED) &&
1890 	    (limits->features & BLK_FEAT_ZONED)) {
1891 		r = dm_revalidate_zones(t, q);
1892 		if (r)
1893 			return r;
1894 	}
1895 
1896 	dm_update_crypto_profile(q, t);
1897 	return 0;
1898 }
1899 
dm_table_get_devices(struct dm_table * t)1900 struct list_head *dm_table_get_devices(struct dm_table *t)
1901 {
1902 	return &t->devices;
1903 }
1904 
dm_table_get_mode(struct dm_table * t)1905 blk_mode_t dm_table_get_mode(struct dm_table *t)
1906 {
1907 	return t->mode;
1908 }
1909 EXPORT_SYMBOL(dm_table_get_mode);
1910 
1911 enum suspend_mode {
1912 	PRESUSPEND,
1913 	PRESUSPEND_UNDO,
1914 	POSTSUSPEND,
1915 };
1916 
suspend_targets(struct dm_table * t,enum suspend_mode mode)1917 static void suspend_targets(struct dm_table *t, enum suspend_mode mode)
1918 {
1919 	lockdep_assert_held(&t->md->suspend_lock);
1920 
1921 	for (unsigned int i = 0; i < t->num_targets; i++) {
1922 		struct dm_target *ti = dm_table_get_target(t, i);
1923 
1924 		switch (mode) {
1925 		case PRESUSPEND:
1926 			if (ti->type->presuspend)
1927 				ti->type->presuspend(ti);
1928 			break;
1929 		case PRESUSPEND_UNDO:
1930 			if (ti->type->presuspend_undo)
1931 				ti->type->presuspend_undo(ti);
1932 			break;
1933 		case POSTSUSPEND:
1934 			if (ti->type->postsuspend)
1935 				ti->type->postsuspend(ti);
1936 			break;
1937 		}
1938 	}
1939 }
1940 
dm_table_presuspend_targets(struct dm_table * t)1941 void dm_table_presuspend_targets(struct dm_table *t)
1942 {
1943 	if (!t)
1944 		return;
1945 
1946 	suspend_targets(t, PRESUSPEND);
1947 }
1948 
dm_table_presuspend_undo_targets(struct dm_table * t)1949 void dm_table_presuspend_undo_targets(struct dm_table *t)
1950 {
1951 	if (!t)
1952 		return;
1953 
1954 	suspend_targets(t, PRESUSPEND_UNDO);
1955 }
1956 
dm_table_postsuspend_targets(struct dm_table * t)1957 void dm_table_postsuspend_targets(struct dm_table *t)
1958 {
1959 	if (!t)
1960 		return;
1961 
1962 	suspend_targets(t, POSTSUSPEND);
1963 }
1964 
dm_table_resume_targets(struct dm_table * t)1965 int dm_table_resume_targets(struct dm_table *t)
1966 {
1967 	unsigned int i;
1968 	int r = 0;
1969 
1970 	lockdep_assert_held(&t->md->suspend_lock);
1971 
1972 	for (i = 0; i < t->num_targets; i++) {
1973 		struct dm_target *ti = dm_table_get_target(t, i);
1974 
1975 		if (!ti->type->preresume)
1976 			continue;
1977 
1978 		r = ti->type->preresume(ti);
1979 		if (r) {
1980 			DMERR("%s: %s: preresume failed, error = %d",
1981 			      dm_device_name(t->md), ti->type->name, r);
1982 			return r;
1983 		}
1984 	}
1985 
1986 	for (i = 0; i < t->num_targets; i++) {
1987 		struct dm_target *ti = dm_table_get_target(t, i);
1988 
1989 		if (ti->type->resume)
1990 			ti->type->resume(ti);
1991 	}
1992 
1993 	return 0;
1994 }
1995 
dm_table_get_md(struct dm_table * t)1996 struct mapped_device *dm_table_get_md(struct dm_table *t)
1997 {
1998 	return t->md;
1999 }
2000 EXPORT_SYMBOL(dm_table_get_md);
2001 
dm_table_device_name(struct dm_table * t)2002 const char *dm_table_device_name(struct dm_table *t)
2003 {
2004 	return dm_device_name(t->md);
2005 }
2006 EXPORT_SYMBOL_GPL(dm_table_device_name);
2007 
dm_table_run_md_queue_async(struct dm_table * t)2008 void dm_table_run_md_queue_async(struct dm_table *t)
2009 {
2010 	if (!dm_table_request_based(t))
2011 		return;
2012 
2013 	if (t->md->queue)
2014 		blk_mq_run_hw_queues(t->md->queue, true);
2015 }
2016 EXPORT_SYMBOL(dm_table_run_md_queue_async);
2017 
2018