xref: /openbmc/linux/fs/btrfs/zoned.c (revision a9d85efb)
1 // SPDX-License-Identifier: GPL-2.0
2 
3 #include <linux/bitops.h>
4 #include <linux/slab.h>
5 #include <linux/blkdev.h>
6 #include <linux/sched/mm.h>
7 #include "ctree.h"
8 #include "volumes.h"
9 #include "zoned.h"
10 #include "rcu-string.h"
11 #include "disk-io.h"
12 #include "block-group.h"
13 #include "transaction.h"
14 #include "dev-replace.h"
15 #include "space-info.h"
16 
17 /* Maximum number of zones to report per blkdev_report_zones() call */
18 #define BTRFS_REPORT_NR_ZONES   4096
19 /* Invalid allocation pointer value for missing devices */
20 #define WP_MISSING_DEV ((u64)-1)
21 /* Pseudo write pointer value for conventional zone */
22 #define WP_CONVENTIONAL ((u64)-2)
23 
24 /*
25  * Location of the first zone of superblock logging zone pairs.
26  *
27  * - primary superblock:    0B (zone 0)
28  * - first copy:          512G (zone starting at that offset)
29  * - second copy:           4T (zone starting at that offset)
30  */
31 #define BTRFS_SB_LOG_PRIMARY_OFFSET	(0ULL)
32 #define BTRFS_SB_LOG_FIRST_OFFSET	(512ULL * SZ_1G)
33 #define BTRFS_SB_LOG_SECOND_OFFSET	(4096ULL * SZ_1G)
34 
35 #define BTRFS_SB_LOG_FIRST_SHIFT	const_ilog2(BTRFS_SB_LOG_FIRST_OFFSET)
36 #define BTRFS_SB_LOG_SECOND_SHIFT	const_ilog2(BTRFS_SB_LOG_SECOND_OFFSET)
37 
38 /* Number of superblock log zones */
39 #define BTRFS_NR_SB_LOG_ZONES 2
40 
41 /*
42  * Maximum supported zone size. Currently, SMR disks have a zone size of
43  * 256MiB, and we are expecting ZNS drives to be in the 1-4GiB range. We do not
44  * expect the zone size to become larger than 8GiB in the near future.
45  */
46 #define BTRFS_MAX_ZONE_SIZE		SZ_8G
47 
48 static int copy_zone_info_cb(struct blk_zone *zone, unsigned int idx, void *data)
49 {
50 	struct blk_zone *zones = data;
51 
52 	memcpy(&zones[idx], zone, sizeof(*zone));
53 
54 	return 0;
55 }
56 
57 static int sb_write_pointer(struct block_device *bdev, struct blk_zone *zones,
58 			    u64 *wp_ret)
59 {
60 	bool empty[BTRFS_NR_SB_LOG_ZONES];
61 	bool full[BTRFS_NR_SB_LOG_ZONES];
62 	sector_t sector;
63 
64 	ASSERT(zones[0].type != BLK_ZONE_TYPE_CONVENTIONAL &&
65 	       zones[1].type != BLK_ZONE_TYPE_CONVENTIONAL);
66 
67 	empty[0] = (zones[0].cond == BLK_ZONE_COND_EMPTY);
68 	empty[1] = (zones[1].cond == BLK_ZONE_COND_EMPTY);
69 	full[0] = (zones[0].cond == BLK_ZONE_COND_FULL);
70 	full[1] = (zones[1].cond == BLK_ZONE_COND_FULL);
71 
72 	/*
73 	 * Possible states of log buffer zones
74 	 *
75 	 *           Empty[0]  In use[0]  Full[0]
76 	 * Empty[1]         *          x        0
77 	 * In use[1]        0          x        0
78 	 * Full[1]          1          1        C
79 	 *
80 	 * Log position:
81 	 *   *: Special case, no superblock is written
82 	 *   0: Use write pointer of zones[0]
83 	 *   1: Use write pointer of zones[1]
84 	 *   C: Compare super blocks from zones[0] and zones[1], use the latest
85 	 *      one determined by generation
86 	 *   x: Invalid state
87 	 */
88 
89 	if (empty[0] && empty[1]) {
90 		/* Special case to distinguish no superblock to read */
91 		*wp_ret = zones[0].start << SECTOR_SHIFT;
92 		return -ENOENT;
93 	} else if (full[0] && full[1]) {
94 		/* Compare two super blocks */
95 		struct address_space *mapping = bdev->bd_inode->i_mapping;
96 		struct page *page[BTRFS_NR_SB_LOG_ZONES];
97 		struct btrfs_super_block *super[BTRFS_NR_SB_LOG_ZONES];
98 		int i;
99 
100 		for (i = 0; i < BTRFS_NR_SB_LOG_ZONES; i++) {
101 			u64 bytenr;
102 
103 			bytenr = ((zones[i].start + zones[i].len)
104 				   << SECTOR_SHIFT) - BTRFS_SUPER_INFO_SIZE;
105 
106 			page[i] = read_cache_page_gfp(mapping,
107 					bytenr >> PAGE_SHIFT, GFP_NOFS);
108 			if (IS_ERR(page[i])) {
109 				if (i == 1)
110 					btrfs_release_disk_super(super[0]);
111 				return PTR_ERR(page[i]);
112 			}
113 			super[i] = page_address(page[i]);
114 		}
115 
116 		if (super[0]->generation > super[1]->generation)
117 			sector = zones[1].start;
118 		else
119 			sector = zones[0].start;
120 
121 		for (i = 0; i < BTRFS_NR_SB_LOG_ZONES; i++)
122 			btrfs_release_disk_super(super[i]);
123 	} else if (!full[0] && (empty[1] || full[1])) {
124 		sector = zones[0].wp;
125 	} else if (full[0]) {
126 		sector = zones[1].wp;
127 	} else {
128 		return -EUCLEAN;
129 	}
130 	*wp_ret = sector << SECTOR_SHIFT;
131 	return 0;
132 }
133 
134 /*
135  * Get the first zone number of the superblock mirror
136  */
137 static inline u32 sb_zone_number(int shift, int mirror)
138 {
139 	u64 zone;
140 
141 	ASSERT(mirror < BTRFS_SUPER_MIRROR_MAX);
142 	switch (mirror) {
143 	case 0: zone = 0; break;
144 	case 1: zone = 1ULL << (BTRFS_SB_LOG_FIRST_SHIFT - shift); break;
145 	case 2: zone = 1ULL << (BTRFS_SB_LOG_SECOND_SHIFT - shift); break;
146 	}
147 
148 	ASSERT(zone <= U32_MAX);
149 
150 	return (u32)zone;
151 }
152 
153 static inline sector_t zone_start_sector(u32 zone_number,
154 					 struct block_device *bdev)
155 {
156 	return (sector_t)zone_number << ilog2(bdev_zone_sectors(bdev));
157 }
158 
159 static inline u64 zone_start_physical(u32 zone_number,
160 				      struct btrfs_zoned_device_info *zone_info)
161 {
162 	return (u64)zone_number << zone_info->zone_size_shift;
163 }
164 
165 /*
166  * Emulate blkdev_report_zones() for a non-zoned device. It slices up the block
167  * device into static sized chunks and fake a conventional zone on each of
168  * them.
169  */
170 static int emulate_report_zones(struct btrfs_device *device, u64 pos,
171 				struct blk_zone *zones, unsigned int nr_zones)
172 {
173 	const sector_t zone_sectors = device->fs_info->zone_size >> SECTOR_SHIFT;
174 	sector_t bdev_size = bdev_nr_sectors(device->bdev);
175 	unsigned int i;
176 
177 	pos >>= SECTOR_SHIFT;
178 	for (i = 0; i < nr_zones; i++) {
179 		zones[i].start = i * zone_sectors + pos;
180 		zones[i].len = zone_sectors;
181 		zones[i].capacity = zone_sectors;
182 		zones[i].wp = zones[i].start + zone_sectors;
183 		zones[i].type = BLK_ZONE_TYPE_CONVENTIONAL;
184 		zones[i].cond = BLK_ZONE_COND_NOT_WP;
185 
186 		if (zones[i].wp >= bdev_size) {
187 			i++;
188 			break;
189 		}
190 	}
191 
192 	return i;
193 }
194 
195 static int btrfs_get_dev_zones(struct btrfs_device *device, u64 pos,
196 			       struct blk_zone *zones, unsigned int *nr_zones)
197 {
198 	int ret;
199 
200 	if (!*nr_zones)
201 		return 0;
202 
203 	if (!bdev_is_zoned(device->bdev)) {
204 		ret = emulate_report_zones(device, pos, zones, *nr_zones);
205 		*nr_zones = ret;
206 		return 0;
207 	}
208 
209 	ret = blkdev_report_zones(device->bdev, pos >> SECTOR_SHIFT, *nr_zones,
210 				  copy_zone_info_cb, zones);
211 	if (ret < 0) {
212 		btrfs_err_in_rcu(device->fs_info,
213 				 "zoned: failed to read zone %llu on %s (devid %llu)",
214 				 pos, rcu_str_deref(device->name),
215 				 device->devid);
216 		return ret;
217 	}
218 	*nr_zones = ret;
219 	if (!ret)
220 		return -EIO;
221 
222 	return 0;
223 }
224 
225 /* The emulated zone size is determined from the size of device extent */
226 static int calculate_emulated_zone_size(struct btrfs_fs_info *fs_info)
227 {
228 	struct btrfs_path *path;
229 	struct btrfs_root *root = fs_info->dev_root;
230 	struct btrfs_key key;
231 	struct extent_buffer *leaf;
232 	struct btrfs_dev_extent *dext;
233 	int ret = 0;
234 
235 	key.objectid = 1;
236 	key.type = BTRFS_DEV_EXTENT_KEY;
237 	key.offset = 0;
238 
239 	path = btrfs_alloc_path();
240 	if (!path)
241 		return -ENOMEM;
242 
243 	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
244 	if (ret < 0)
245 		goto out;
246 
247 	if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
248 		ret = btrfs_next_leaf(root, path);
249 		if (ret < 0)
250 			goto out;
251 		/* No dev extents at all? Not good */
252 		if (ret > 0) {
253 			ret = -EUCLEAN;
254 			goto out;
255 		}
256 	}
257 
258 	leaf = path->nodes[0];
259 	dext = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_extent);
260 	fs_info->zone_size = btrfs_dev_extent_length(leaf, dext);
261 	ret = 0;
262 
263 out:
264 	btrfs_free_path(path);
265 
266 	return ret;
267 }
268 
269 int btrfs_get_dev_zone_info_all_devices(struct btrfs_fs_info *fs_info)
270 {
271 	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
272 	struct btrfs_device *device;
273 	int ret = 0;
274 
275 	/* fs_info->zone_size might not set yet. Use the incomapt flag here. */
276 	if (!btrfs_fs_incompat(fs_info, ZONED))
277 		return 0;
278 
279 	mutex_lock(&fs_devices->device_list_mutex);
280 	list_for_each_entry(device, &fs_devices->devices, dev_list) {
281 		/* We can skip reading of zone info for missing devices */
282 		if (!device->bdev)
283 			continue;
284 
285 		ret = btrfs_get_dev_zone_info(device);
286 		if (ret)
287 			break;
288 	}
289 	mutex_unlock(&fs_devices->device_list_mutex);
290 
291 	return ret;
292 }
293 
294 int btrfs_get_dev_zone_info(struct btrfs_device *device)
295 {
296 	struct btrfs_fs_info *fs_info = device->fs_info;
297 	struct btrfs_zoned_device_info *zone_info = NULL;
298 	struct block_device *bdev = device->bdev;
299 	sector_t nr_sectors;
300 	sector_t sector = 0;
301 	struct blk_zone *zones = NULL;
302 	unsigned int i, nreported = 0, nr_zones;
303 	sector_t zone_sectors;
304 	char *model, *emulated;
305 	int ret;
306 
307 	/*
308 	 * Cannot use btrfs_is_zoned here, since fs_info::zone_size might not
309 	 * yet be set.
310 	 */
311 	if (!btrfs_fs_incompat(fs_info, ZONED))
312 		return 0;
313 
314 	if (device->zone_info)
315 		return 0;
316 
317 	zone_info = kzalloc(sizeof(*zone_info), GFP_KERNEL);
318 	if (!zone_info)
319 		return -ENOMEM;
320 
321 	if (!bdev_is_zoned(bdev)) {
322 		if (!fs_info->zone_size) {
323 			ret = calculate_emulated_zone_size(fs_info);
324 			if (ret)
325 				goto out;
326 		}
327 
328 		ASSERT(fs_info->zone_size);
329 		zone_sectors = fs_info->zone_size >> SECTOR_SHIFT;
330 	} else {
331 		zone_sectors = bdev_zone_sectors(bdev);
332 	}
333 
334 	/* Check if it's power of 2 (see is_power_of_2) */
335 	ASSERT(zone_sectors != 0 && (zone_sectors & (zone_sectors - 1)) == 0);
336 	zone_info->zone_size = zone_sectors << SECTOR_SHIFT;
337 
338 	/* We reject devices with a zone size larger than 8GB */
339 	if (zone_info->zone_size > BTRFS_MAX_ZONE_SIZE) {
340 		btrfs_err_in_rcu(fs_info,
341 		"zoned: %s: zone size %llu larger than supported maximum %llu",
342 				 rcu_str_deref(device->name),
343 				 zone_info->zone_size, BTRFS_MAX_ZONE_SIZE);
344 		ret = -EINVAL;
345 		goto out;
346 	}
347 
348 	nr_sectors = bdev_nr_sectors(bdev);
349 	zone_info->zone_size_shift = ilog2(zone_info->zone_size);
350 	zone_info->nr_zones = nr_sectors >> ilog2(zone_sectors);
351 	if (!IS_ALIGNED(nr_sectors, zone_sectors))
352 		zone_info->nr_zones++;
353 
354 	zone_info->seq_zones = bitmap_zalloc(zone_info->nr_zones, GFP_KERNEL);
355 	if (!zone_info->seq_zones) {
356 		ret = -ENOMEM;
357 		goto out;
358 	}
359 
360 	zone_info->empty_zones = bitmap_zalloc(zone_info->nr_zones, GFP_KERNEL);
361 	if (!zone_info->empty_zones) {
362 		ret = -ENOMEM;
363 		goto out;
364 	}
365 
366 	zones = kcalloc(BTRFS_REPORT_NR_ZONES, sizeof(struct blk_zone), GFP_KERNEL);
367 	if (!zones) {
368 		ret = -ENOMEM;
369 		goto out;
370 	}
371 
372 	/* Get zones type */
373 	while (sector < nr_sectors) {
374 		nr_zones = BTRFS_REPORT_NR_ZONES;
375 		ret = btrfs_get_dev_zones(device, sector << SECTOR_SHIFT, zones,
376 					  &nr_zones);
377 		if (ret)
378 			goto out;
379 
380 		for (i = 0; i < nr_zones; i++) {
381 			if (zones[i].type == BLK_ZONE_TYPE_SEQWRITE_REQ)
382 				__set_bit(nreported, zone_info->seq_zones);
383 			if (zones[i].cond == BLK_ZONE_COND_EMPTY)
384 				__set_bit(nreported, zone_info->empty_zones);
385 			nreported++;
386 		}
387 		sector = zones[nr_zones - 1].start + zones[nr_zones - 1].len;
388 	}
389 
390 	if (nreported != zone_info->nr_zones) {
391 		btrfs_err_in_rcu(device->fs_info,
392 				 "inconsistent number of zones on %s (%u/%u)",
393 				 rcu_str_deref(device->name), nreported,
394 				 zone_info->nr_zones);
395 		ret = -EIO;
396 		goto out;
397 	}
398 
399 	/* Validate superblock log */
400 	nr_zones = BTRFS_NR_SB_LOG_ZONES;
401 	for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
402 		u32 sb_zone;
403 		u64 sb_wp;
404 		int sb_pos = BTRFS_NR_SB_LOG_ZONES * i;
405 
406 		sb_zone = sb_zone_number(zone_info->zone_size_shift, i);
407 		if (sb_zone + 1 >= zone_info->nr_zones)
408 			continue;
409 
410 		ret = btrfs_get_dev_zones(device,
411 					  zone_start_physical(sb_zone, zone_info),
412 					  &zone_info->sb_zones[sb_pos],
413 					  &nr_zones);
414 		if (ret)
415 			goto out;
416 
417 		if (nr_zones != BTRFS_NR_SB_LOG_ZONES) {
418 			btrfs_err_in_rcu(device->fs_info,
419 	"zoned: failed to read super block log zone info at devid %llu zone %u",
420 					 device->devid, sb_zone);
421 			ret = -EUCLEAN;
422 			goto out;
423 		}
424 
425 		/*
426 		 * If zones[0] is conventional, always use the beginning of the
427 		 * zone to record superblock. No need to validate in that case.
428 		 */
429 		if (zone_info->sb_zones[BTRFS_NR_SB_LOG_ZONES * i].type ==
430 		    BLK_ZONE_TYPE_CONVENTIONAL)
431 			continue;
432 
433 		ret = sb_write_pointer(device->bdev,
434 				       &zone_info->sb_zones[sb_pos], &sb_wp);
435 		if (ret != -ENOENT && ret) {
436 			btrfs_err_in_rcu(device->fs_info,
437 			"zoned: super block log zone corrupted devid %llu zone %u",
438 					 device->devid, sb_zone);
439 			ret = -EUCLEAN;
440 			goto out;
441 		}
442 	}
443 
444 
445 	kfree(zones);
446 
447 	device->zone_info = zone_info;
448 
449 	switch (bdev_zoned_model(bdev)) {
450 	case BLK_ZONED_HM:
451 		model = "host-managed zoned";
452 		emulated = "";
453 		break;
454 	case BLK_ZONED_HA:
455 		model = "host-aware zoned";
456 		emulated = "";
457 		break;
458 	case BLK_ZONED_NONE:
459 		model = "regular";
460 		emulated = "emulated ";
461 		break;
462 	default:
463 		/* Just in case */
464 		btrfs_err_in_rcu(fs_info, "zoned: unsupported model %d on %s",
465 				 bdev_zoned_model(bdev),
466 				 rcu_str_deref(device->name));
467 		ret = -EOPNOTSUPP;
468 		goto out_free_zone_info;
469 	}
470 
471 	btrfs_info_in_rcu(fs_info,
472 		"%s block device %s, %u %szones of %llu bytes",
473 		model, rcu_str_deref(device->name), zone_info->nr_zones,
474 		emulated, zone_info->zone_size);
475 
476 	return 0;
477 
478 out:
479 	kfree(zones);
480 out_free_zone_info:
481 	bitmap_free(zone_info->empty_zones);
482 	bitmap_free(zone_info->seq_zones);
483 	kfree(zone_info);
484 	device->zone_info = NULL;
485 
486 	return ret;
487 }
488 
489 void btrfs_destroy_dev_zone_info(struct btrfs_device *device)
490 {
491 	struct btrfs_zoned_device_info *zone_info = device->zone_info;
492 
493 	if (!zone_info)
494 		return;
495 
496 	bitmap_free(zone_info->seq_zones);
497 	bitmap_free(zone_info->empty_zones);
498 	kfree(zone_info);
499 	device->zone_info = NULL;
500 }
501 
502 int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
503 		       struct blk_zone *zone)
504 {
505 	unsigned int nr_zones = 1;
506 	int ret;
507 
508 	ret = btrfs_get_dev_zones(device, pos, zone, &nr_zones);
509 	if (ret != 0 || !nr_zones)
510 		return ret ? ret : -EIO;
511 
512 	return 0;
513 }
514 
515 int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info)
516 {
517 	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
518 	struct btrfs_device *device;
519 	u64 zoned_devices = 0;
520 	u64 nr_devices = 0;
521 	u64 zone_size = 0;
522 	const bool incompat_zoned = btrfs_fs_incompat(fs_info, ZONED);
523 	int ret = 0;
524 
525 	/* Count zoned devices */
526 	list_for_each_entry(device, &fs_devices->devices, dev_list) {
527 		enum blk_zoned_model model;
528 
529 		if (!device->bdev)
530 			continue;
531 
532 		model = bdev_zoned_model(device->bdev);
533 		/*
534 		 * A Host-Managed zoned device must be used as a zoned device.
535 		 * A Host-Aware zoned device and a non-zoned devices can be
536 		 * treated as a zoned device, if ZONED flag is enabled in the
537 		 * superblock.
538 		 */
539 		if (model == BLK_ZONED_HM ||
540 		    (model == BLK_ZONED_HA && incompat_zoned) ||
541 		    (model == BLK_ZONED_NONE && incompat_zoned)) {
542 			struct btrfs_zoned_device_info *zone_info =
543 				device->zone_info;
544 
545 			zone_info = device->zone_info;
546 			zoned_devices++;
547 			if (!zone_size) {
548 				zone_size = zone_info->zone_size;
549 			} else if (zone_info->zone_size != zone_size) {
550 				btrfs_err(fs_info,
551 		"zoned: unequal block device zone sizes: have %llu found %llu",
552 					  device->zone_info->zone_size,
553 					  zone_size);
554 				ret = -EINVAL;
555 				goto out;
556 			}
557 		}
558 		nr_devices++;
559 	}
560 
561 	if (!zoned_devices && !incompat_zoned)
562 		goto out;
563 
564 	if (!zoned_devices && incompat_zoned) {
565 		/* No zoned block device found on ZONED filesystem */
566 		btrfs_err(fs_info,
567 			  "zoned: no zoned devices found on a zoned filesystem");
568 		ret = -EINVAL;
569 		goto out;
570 	}
571 
572 	if (zoned_devices && !incompat_zoned) {
573 		btrfs_err(fs_info,
574 			  "zoned: mode not enabled but zoned device found");
575 		ret = -EINVAL;
576 		goto out;
577 	}
578 
579 	if (zoned_devices != nr_devices) {
580 		btrfs_err(fs_info,
581 			  "zoned: cannot mix zoned and regular devices");
582 		ret = -EINVAL;
583 		goto out;
584 	}
585 
586 	/*
587 	 * stripe_size is always aligned to BTRFS_STRIPE_LEN in
588 	 * __btrfs_alloc_chunk(). Since we want stripe_len == zone_size,
589 	 * check the alignment here.
590 	 */
591 	if (!IS_ALIGNED(zone_size, BTRFS_STRIPE_LEN)) {
592 		btrfs_err(fs_info,
593 			  "zoned: zone size %llu not aligned to stripe %u",
594 			  zone_size, BTRFS_STRIPE_LEN);
595 		ret = -EINVAL;
596 		goto out;
597 	}
598 
599 	if (btrfs_fs_incompat(fs_info, MIXED_GROUPS)) {
600 		btrfs_err(fs_info, "zoned: mixed block groups not supported");
601 		ret = -EINVAL;
602 		goto out;
603 	}
604 
605 	fs_info->zone_size = zone_size;
606 	fs_info->fs_devices->chunk_alloc_policy = BTRFS_CHUNK_ALLOC_ZONED;
607 
608 	/*
609 	 * Check mount options here, because we might change fs_info->zoned
610 	 * from fs_info->zone_size.
611 	 */
612 	ret = btrfs_check_mountopts_zoned(fs_info);
613 	if (ret)
614 		goto out;
615 
616 	btrfs_info(fs_info, "zoned mode enabled with zone size %llu", zone_size);
617 out:
618 	return ret;
619 }
620 
621 int btrfs_check_mountopts_zoned(struct btrfs_fs_info *info)
622 {
623 	if (!btrfs_is_zoned(info))
624 		return 0;
625 
626 	/*
627 	 * Space cache writing is not COWed. Disable that to avoid write errors
628 	 * in sequential zones.
629 	 */
630 	if (btrfs_test_opt(info, SPACE_CACHE)) {
631 		btrfs_err(info, "zoned: space cache v1 is not supported");
632 		return -EINVAL;
633 	}
634 
635 	if (btrfs_test_opt(info, NODATACOW)) {
636 		btrfs_err(info, "zoned: NODATACOW not supported");
637 		return -EINVAL;
638 	}
639 
640 	return 0;
641 }
642 
643 static int sb_log_location(struct block_device *bdev, struct blk_zone *zones,
644 			   int rw, u64 *bytenr_ret)
645 {
646 	u64 wp;
647 	int ret;
648 
649 	if (zones[0].type == BLK_ZONE_TYPE_CONVENTIONAL) {
650 		*bytenr_ret = zones[0].start << SECTOR_SHIFT;
651 		return 0;
652 	}
653 
654 	ret = sb_write_pointer(bdev, zones, &wp);
655 	if (ret != -ENOENT && ret < 0)
656 		return ret;
657 
658 	if (rw == WRITE) {
659 		struct blk_zone *reset = NULL;
660 
661 		if (wp == zones[0].start << SECTOR_SHIFT)
662 			reset = &zones[0];
663 		else if (wp == zones[1].start << SECTOR_SHIFT)
664 			reset = &zones[1];
665 
666 		if (reset && reset->cond != BLK_ZONE_COND_EMPTY) {
667 			ASSERT(reset->cond == BLK_ZONE_COND_FULL);
668 
669 			ret = blkdev_zone_mgmt(bdev, REQ_OP_ZONE_RESET,
670 					       reset->start, reset->len,
671 					       GFP_NOFS);
672 			if (ret)
673 				return ret;
674 
675 			reset->cond = BLK_ZONE_COND_EMPTY;
676 			reset->wp = reset->start;
677 		}
678 	} else if (ret != -ENOENT) {
679 		/* For READ, we want the precious one */
680 		if (wp == zones[0].start << SECTOR_SHIFT)
681 			wp = (zones[1].start + zones[1].len) << SECTOR_SHIFT;
682 		wp -= BTRFS_SUPER_INFO_SIZE;
683 	}
684 
685 	*bytenr_ret = wp;
686 	return 0;
687 
688 }
689 
690 int btrfs_sb_log_location_bdev(struct block_device *bdev, int mirror, int rw,
691 			       u64 *bytenr_ret)
692 {
693 	struct blk_zone zones[BTRFS_NR_SB_LOG_ZONES];
694 	sector_t zone_sectors;
695 	u32 sb_zone;
696 	int ret;
697 	u8 zone_sectors_shift;
698 	sector_t nr_sectors;
699 	u32 nr_zones;
700 
701 	if (!bdev_is_zoned(bdev)) {
702 		*bytenr_ret = btrfs_sb_offset(mirror);
703 		return 0;
704 	}
705 
706 	ASSERT(rw == READ || rw == WRITE);
707 
708 	zone_sectors = bdev_zone_sectors(bdev);
709 	if (!is_power_of_2(zone_sectors))
710 		return -EINVAL;
711 	zone_sectors_shift = ilog2(zone_sectors);
712 	nr_sectors = bdev_nr_sectors(bdev);
713 	nr_zones = nr_sectors >> zone_sectors_shift;
714 
715 	sb_zone = sb_zone_number(zone_sectors_shift + SECTOR_SHIFT, mirror);
716 	if (sb_zone + 1 >= nr_zones)
717 		return -ENOENT;
718 
719 	ret = blkdev_report_zones(bdev, zone_start_sector(sb_zone, bdev),
720 				  BTRFS_NR_SB_LOG_ZONES, copy_zone_info_cb,
721 				  zones);
722 	if (ret < 0)
723 		return ret;
724 	if (ret != BTRFS_NR_SB_LOG_ZONES)
725 		return -EIO;
726 
727 	return sb_log_location(bdev, zones, rw, bytenr_ret);
728 }
729 
730 int btrfs_sb_log_location(struct btrfs_device *device, int mirror, int rw,
731 			  u64 *bytenr_ret)
732 {
733 	struct btrfs_zoned_device_info *zinfo = device->zone_info;
734 	u32 zone_num;
735 
736 	/*
737 	 * For a zoned filesystem on a non-zoned block device, use the same
738 	 * super block locations as regular filesystem. Doing so, the super
739 	 * block can always be retrieved and the zoned flag of the volume
740 	 * detected from the super block information.
741 	 */
742 	if (!bdev_is_zoned(device->bdev)) {
743 		*bytenr_ret = btrfs_sb_offset(mirror);
744 		return 0;
745 	}
746 
747 	zone_num = sb_zone_number(zinfo->zone_size_shift, mirror);
748 	if (zone_num + 1 >= zinfo->nr_zones)
749 		return -ENOENT;
750 
751 	return sb_log_location(device->bdev,
752 			       &zinfo->sb_zones[BTRFS_NR_SB_LOG_ZONES * mirror],
753 			       rw, bytenr_ret);
754 }
755 
756 static inline bool is_sb_log_zone(struct btrfs_zoned_device_info *zinfo,
757 				  int mirror)
758 {
759 	u32 zone_num;
760 
761 	if (!zinfo)
762 		return false;
763 
764 	zone_num = sb_zone_number(zinfo->zone_size_shift, mirror);
765 	if (zone_num + 1 >= zinfo->nr_zones)
766 		return false;
767 
768 	if (!test_bit(zone_num, zinfo->seq_zones))
769 		return false;
770 
771 	return true;
772 }
773 
774 void btrfs_advance_sb_log(struct btrfs_device *device, int mirror)
775 {
776 	struct btrfs_zoned_device_info *zinfo = device->zone_info;
777 	struct blk_zone *zone;
778 
779 	if (!is_sb_log_zone(zinfo, mirror))
780 		return;
781 
782 	zone = &zinfo->sb_zones[BTRFS_NR_SB_LOG_ZONES * mirror];
783 	if (zone->cond != BLK_ZONE_COND_FULL) {
784 		if (zone->cond == BLK_ZONE_COND_EMPTY)
785 			zone->cond = BLK_ZONE_COND_IMP_OPEN;
786 
787 		zone->wp += (BTRFS_SUPER_INFO_SIZE >> SECTOR_SHIFT);
788 
789 		if (zone->wp == zone->start + zone->len)
790 			zone->cond = BLK_ZONE_COND_FULL;
791 
792 		return;
793 	}
794 
795 	zone++;
796 	ASSERT(zone->cond != BLK_ZONE_COND_FULL);
797 	if (zone->cond == BLK_ZONE_COND_EMPTY)
798 		zone->cond = BLK_ZONE_COND_IMP_OPEN;
799 
800 	zone->wp += (BTRFS_SUPER_INFO_SIZE >> SECTOR_SHIFT);
801 
802 	if (zone->wp == zone->start + zone->len)
803 		zone->cond = BLK_ZONE_COND_FULL;
804 }
805 
806 int btrfs_reset_sb_log_zones(struct block_device *bdev, int mirror)
807 {
808 	sector_t zone_sectors;
809 	sector_t nr_sectors;
810 	u8 zone_sectors_shift;
811 	u32 sb_zone;
812 	u32 nr_zones;
813 
814 	zone_sectors = bdev_zone_sectors(bdev);
815 	zone_sectors_shift = ilog2(zone_sectors);
816 	nr_sectors = bdev_nr_sectors(bdev);
817 	nr_zones = nr_sectors >> zone_sectors_shift;
818 
819 	sb_zone = sb_zone_number(zone_sectors_shift + SECTOR_SHIFT, mirror);
820 	if (sb_zone + 1 >= nr_zones)
821 		return -ENOENT;
822 
823 	return blkdev_zone_mgmt(bdev, REQ_OP_ZONE_RESET,
824 				zone_start_sector(sb_zone, bdev),
825 				zone_sectors * BTRFS_NR_SB_LOG_ZONES, GFP_NOFS);
826 }
827 
828 /**
829  * btrfs_find_allocatable_zones - find allocatable zones within a given region
830  *
831  * @device:	the device to allocate a region on
832  * @hole_start: the position of the hole to allocate the region
833  * @num_bytes:	size of wanted region
834  * @hole_end:	the end of the hole
835  * @return:	position of allocatable zones
836  *
837  * Allocatable region should not contain any superblock locations.
838  */
839 u64 btrfs_find_allocatable_zones(struct btrfs_device *device, u64 hole_start,
840 				 u64 hole_end, u64 num_bytes)
841 {
842 	struct btrfs_zoned_device_info *zinfo = device->zone_info;
843 	const u8 shift = zinfo->zone_size_shift;
844 	u64 nzones = num_bytes >> shift;
845 	u64 pos = hole_start;
846 	u64 begin, end;
847 	bool have_sb;
848 	int i;
849 
850 	ASSERT(IS_ALIGNED(hole_start, zinfo->zone_size));
851 	ASSERT(IS_ALIGNED(num_bytes, zinfo->zone_size));
852 
853 	while (pos < hole_end) {
854 		begin = pos >> shift;
855 		end = begin + nzones;
856 
857 		if (end > zinfo->nr_zones)
858 			return hole_end;
859 
860 		/* Check if zones in the region are all empty */
861 		if (btrfs_dev_is_sequential(device, pos) &&
862 		    find_next_zero_bit(zinfo->empty_zones, end, begin) != end) {
863 			pos += zinfo->zone_size;
864 			continue;
865 		}
866 
867 		have_sb = false;
868 		for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
869 			u32 sb_zone;
870 			u64 sb_pos;
871 
872 			sb_zone = sb_zone_number(shift, i);
873 			if (!(end <= sb_zone ||
874 			      sb_zone + BTRFS_NR_SB_LOG_ZONES <= begin)) {
875 				have_sb = true;
876 				pos = zone_start_physical(
877 					sb_zone + BTRFS_NR_SB_LOG_ZONES, zinfo);
878 				break;
879 			}
880 
881 			/* We also need to exclude regular superblock positions */
882 			sb_pos = btrfs_sb_offset(i);
883 			if (!(pos + num_bytes <= sb_pos ||
884 			      sb_pos + BTRFS_SUPER_INFO_SIZE <= pos)) {
885 				have_sb = true;
886 				pos = ALIGN(sb_pos + BTRFS_SUPER_INFO_SIZE,
887 					    zinfo->zone_size);
888 				break;
889 			}
890 		}
891 		if (!have_sb)
892 			break;
893 	}
894 
895 	return pos;
896 }
897 
898 int btrfs_reset_device_zone(struct btrfs_device *device, u64 physical,
899 			    u64 length, u64 *bytes)
900 {
901 	int ret;
902 
903 	*bytes = 0;
904 	ret = blkdev_zone_mgmt(device->bdev, REQ_OP_ZONE_RESET,
905 			       physical >> SECTOR_SHIFT, length >> SECTOR_SHIFT,
906 			       GFP_NOFS);
907 	if (ret)
908 		return ret;
909 
910 	*bytes = length;
911 	while (length) {
912 		btrfs_dev_set_zone_empty(device, physical);
913 		physical += device->zone_info->zone_size;
914 		length -= device->zone_info->zone_size;
915 	}
916 
917 	return 0;
918 }
919 
920 int btrfs_ensure_empty_zones(struct btrfs_device *device, u64 start, u64 size)
921 {
922 	struct btrfs_zoned_device_info *zinfo = device->zone_info;
923 	const u8 shift = zinfo->zone_size_shift;
924 	unsigned long begin = start >> shift;
925 	unsigned long end = (start + size) >> shift;
926 	u64 pos;
927 	int ret;
928 
929 	ASSERT(IS_ALIGNED(start, zinfo->zone_size));
930 	ASSERT(IS_ALIGNED(size, zinfo->zone_size));
931 
932 	if (end > zinfo->nr_zones)
933 		return -ERANGE;
934 
935 	/* All the zones are conventional */
936 	if (find_next_bit(zinfo->seq_zones, begin, end) == end)
937 		return 0;
938 
939 	/* All the zones are sequential and empty */
940 	if (find_next_zero_bit(zinfo->seq_zones, begin, end) == end &&
941 	    find_next_zero_bit(zinfo->empty_zones, begin, end) == end)
942 		return 0;
943 
944 	for (pos = start; pos < start + size; pos += zinfo->zone_size) {
945 		u64 reset_bytes;
946 
947 		if (!btrfs_dev_is_sequential(device, pos) ||
948 		    btrfs_dev_is_empty_zone(device, pos))
949 			continue;
950 
951 		/* Free regions should be empty */
952 		btrfs_warn_in_rcu(
953 			device->fs_info,
954 		"zoned: resetting device %s (devid %llu) zone %llu for allocation",
955 			rcu_str_deref(device->name), device->devid, pos >> shift);
956 		WARN_ON_ONCE(1);
957 
958 		ret = btrfs_reset_device_zone(device, pos, zinfo->zone_size,
959 					      &reset_bytes);
960 		if (ret)
961 			return ret;
962 	}
963 
964 	return 0;
965 }
966 
967 /*
968  * Calculate an allocation pointer from the extent allocation information
969  * for a block group consist of conventional zones. It is pointed to the
970  * end of the highest addressed extent in the block group as an allocation
971  * offset.
972  */
973 static int calculate_alloc_pointer(struct btrfs_block_group *cache,
974 				   u64 *offset_ret)
975 {
976 	struct btrfs_fs_info *fs_info = cache->fs_info;
977 	struct btrfs_root *root = fs_info->extent_root;
978 	struct btrfs_path *path;
979 	struct btrfs_key key;
980 	struct btrfs_key found_key;
981 	int ret;
982 	u64 length;
983 
984 	path = btrfs_alloc_path();
985 	if (!path)
986 		return -ENOMEM;
987 
988 	key.objectid = cache->start + cache->length;
989 	key.type = 0;
990 	key.offset = 0;
991 
992 	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
993 	/* We should not find the exact match */
994 	if (!ret)
995 		ret = -EUCLEAN;
996 	if (ret < 0)
997 		goto out;
998 
999 	ret = btrfs_previous_extent_item(root, path, cache->start);
1000 	if (ret) {
1001 		if (ret == 1) {
1002 			ret = 0;
1003 			*offset_ret = 0;
1004 		}
1005 		goto out;
1006 	}
1007 
1008 	btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
1009 
1010 	if (found_key.type == BTRFS_EXTENT_ITEM_KEY)
1011 		length = found_key.offset;
1012 	else
1013 		length = fs_info->nodesize;
1014 
1015 	if (!(found_key.objectid >= cache->start &&
1016 	       found_key.objectid + length <= cache->start + cache->length)) {
1017 		ret = -EUCLEAN;
1018 		goto out;
1019 	}
1020 	*offset_ret = found_key.objectid + length - cache->start;
1021 	ret = 0;
1022 
1023 out:
1024 	btrfs_free_path(path);
1025 	return ret;
1026 }
1027 
1028 int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache, bool new)
1029 {
1030 	struct btrfs_fs_info *fs_info = cache->fs_info;
1031 	struct extent_map_tree *em_tree = &fs_info->mapping_tree;
1032 	struct extent_map *em;
1033 	struct map_lookup *map;
1034 	struct btrfs_device *device;
1035 	u64 logical = cache->start;
1036 	u64 length = cache->length;
1037 	u64 physical = 0;
1038 	int ret;
1039 	int i;
1040 	unsigned int nofs_flag;
1041 	u64 *alloc_offsets = NULL;
1042 	u64 last_alloc = 0;
1043 	u32 num_sequential = 0, num_conventional = 0;
1044 
1045 	if (!btrfs_is_zoned(fs_info))
1046 		return 0;
1047 
1048 	/* Sanity check */
1049 	if (!IS_ALIGNED(length, fs_info->zone_size)) {
1050 		btrfs_err(fs_info,
1051 		"zoned: block group %llu len %llu unaligned to zone size %llu",
1052 			  logical, length, fs_info->zone_size);
1053 		return -EIO;
1054 	}
1055 
1056 	/* Get the chunk mapping */
1057 	read_lock(&em_tree->lock);
1058 	em = lookup_extent_mapping(em_tree, logical, length);
1059 	read_unlock(&em_tree->lock);
1060 
1061 	if (!em)
1062 		return -EINVAL;
1063 
1064 	map = em->map_lookup;
1065 
1066 	alloc_offsets = kcalloc(map->num_stripes, sizeof(*alloc_offsets), GFP_NOFS);
1067 	if (!alloc_offsets) {
1068 		free_extent_map(em);
1069 		return -ENOMEM;
1070 	}
1071 
1072 	for (i = 0; i < map->num_stripes; i++) {
1073 		bool is_sequential;
1074 		struct blk_zone zone;
1075 		struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
1076 		int dev_replace_is_ongoing = 0;
1077 
1078 		device = map->stripes[i].dev;
1079 		physical = map->stripes[i].physical;
1080 
1081 		if (device->bdev == NULL) {
1082 			alloc_offsets[i] = WP_MISSING_DEV;
1083 			continue;
1084 		}
1085 
1086 		is_sequential = btrfs_dev_is_sequential(device, physical);
1087 		if (is_sequential)
1088 			num_sequential++;
1089 		else
1090 			num_conventional++;
1091 
1092 		if (!is_sequential) {
1093 			alloc_offsets[i] = WP_CONVENTIONAL;
1094 			continue;
1095 		}
1096 
1097 		/*
1098 		 * This zone will be used for allocation, so mark this zone
1099 		 * non-empty.
1100 		 */
1101 		btrfs_dev_clear_zone_empty(device, physical);
1102 
1103 		down_read(&dev_replace->rwsem);
1104 		dev_replace_is_ongoing = btrfs_dev_replace_is_ongoing(dev_replace);
1105 		if (dev_replace_is_ongoing && dev_replace->tgtdev != NULL)
1106 			btrfs_dev_clear_zone_empty(dev_replace->tgtdev, physical);
1107 		up_read(&dev_replace->rwsem);
1108 
1109 		/*
1110 		 * The group is mapped to a sequential zone. Get the zone write
1111 		 * pointer to determine the allocation offset within the zone.
1112 		 */
1113 		WARN_ON(!IS_ALIGNED(physical, fs_info->zone_size));
1114 		nofs_flag = memalloc_nofs_save();
1115 		ret = btrfs_get_dev_zone(device, physical, &zone);
1116 		memalloc_nofs_restore(nofs_flag);
1117 		if (ret == -EIO || ret == -EOPNOTSUPP) {
1118 			ret = 0;
1119 			alloc_offsets[i] = WP_MISSING_DEV;
1120 			continue;
1121 		} else if (ret) {
1122 			goto out;
1123 		}
1124 
1125 		if (zone.type == BLK_ZONE_TYPE_CONVENTIONAL) {
1126 			btrfs_err_in_rcu(fs_info,
1127 	"zoned: unexpected conventional zone %llu on device %s (devid %llu)",
1128 				zone.start << SECTOR_SHIFT,
1129 				rcu_str_deref(device->name), device->devid);
1130 			ret = -EIO;
1131 			goto out;
1132 		}
1133 
1134 		switch (zone.cond) {
1135 		case BLK_ZONE_COND_OFFLINE:
1136 		case BLK_ZONE_COND_READONLY:
1137 			btrfs_err(fs_info,
1138 		"zoned: offline/readonly zone %llu on device %s (devid %llu)",
1139 				  physical >> device->zone_info->zone_size_shift,
1140 				  rcu_str_deref(device->name), device->devid);
1141 			alloc_offsets[i] = WP_MISSING_DEV;
1142 			break;
1143 		case BLK_ZONE_COND_EMPTY:
1144 			alloc_offsets[i] = 0;
1145 			break;
1146 		case BLK_ZONE_COND_FULL:
1147 			alloc_offsets[i] = fs_info->zone_size;
1148 			break;
1149 		default:
1150 			/* Partially used zone */
1151 			alloc_offsets[i] =
1152 					((zone.wp - zone.start) << SECTOR_SHIFT);
1153 			break;
1154 		}
1155 	}
1156 
1157 	if (num_sequential > 0)
1158 		cache->seq_zone = true;
1159 
1160 	if (num_conventional > 0) {
1161 		/*
1162 		 * Avoid calling calculate_alloc_pointer() for new BG. It
1163 		 * is no use for new BG. It must be always 0.
1164 		 *
1165 		 * Also, we have a lock chain of extent buffer lock ->
1166 		 * chunk mutex.  For new BG, this function is called from
1167 		 * btrfs_make_block_group() which is already taking the
1168 		 * chunk mutex. Thus, we cannot call
1169 		 * calculate_alloc_pointer() which takes extent buffer
1170 		 * locks to avoid deadlock.
1171 		 */
1172 		if (new) {
1173 			cache->alloc_offset = 0;
1174 			goto out;
1175 		}
1176 		ret = calculate_alloc_pointer(cache, &last_alloc);
1177 		if (ret || map->num_stripes == num_conventional) {
1178 			if (!ret)
1179 				cache->alloc_offset = last_alloc;
1180 			else
1181 				btrfs_err(fs_info,
1182 			"zoned: failed to determine allocation offset of bg %llu",
1183 					  cache->start);
1184 			goto out;
1185 		}
1186 	}
1187 
1188 	switch (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
1189 	case 0: /* single */
1190 		if (alloc_offsets[0] == WP_MISSING_DEV) {
1191 			btrfs_err(fs_info,
1192 			"zoned: cannot recover write pointer for zone %llu",
1193 				physical);
1194 			ret = -EIO;
1195 			goto out;
1196 		}
1197 		cache->alloc_offset = alloc_offsets[0];
1198 		break;
1199 	case BTRFS_BLOCK_GROUP_DUP:
1200 	case BTRFS_BLOCK_GROUP_RAID1:
1201 	case BTRFS_BLOCK_GROUP_RAID0:
1202 	case BTRFS_BLOCK_GROUP_RAID10:
1203 	case BTRFS_BLOCK_GROUP_RAID5:
1204 	case BTRFS_BLOCK_GROUP_RAID6:
1205 		/* non-single profiles are not supported yet */
1206 	default:
1207 		btrfs_err(fs_info, "zoned: profile %s not yet supported",
1208 			  btrfs_bg_type_to_raid_name(map->type));
1209 		ret = -EINVAL;
1210 		goto out;
1211 	}
1212 
1213 out:
1214 	if (cache->alloc_offset > fs_info->zone_size) {
1215 		btrfs_err(fs_info,
1216 			"zoned: invalid write pointer %llu in block group %llu",
1217 			cache->alloc_offset, cache->start);
1218 		ret = -EIO;
1219 	}
1220 
1221 	/* An extent is allocated after the write pointer */
1222 	if (!ret && num_conventional && last_alloc > cache->alloc_offset) {
1223 		btrfs_err(fs_info,
1224 			  "zoned: got wrong write pointer in BG %llu: %llu > %llu",
1225 			  logical, last_alloc, cache->alloc_offset);
1226 		ret = -EIO;
1227 	}
1228 
1229 	if (!ret)
1230 		cache->meta_write_pointer = cache->alloc_offset + cache->start;
1231 
1232 	kfree(alloc_offsets);
1233 	free_extent_map(em);
1234 
1235 	return ret;
1236 }
1237 
1238 void btrfs_calc_zone_unusable(struct btrfs_block_group *cache)
1239 {
1240 	u64 unusable, free;
1241 
1242 	if (!btrfs_is_zoned(cache->fs_info))
1243 		return;
1244 
1245 	WARN_ON(cache->bytes_super != 0);
1246 	unusable = cache->alloc_offset - cache->used;
1247 	free = cache->length - cache->alloc_offset;
1248 
1249 	/* We only need ->free_space in ALLOC_SEQ block groups */
1250 	cache->last_byte_to_unpin = (u64)-1;
1251 	cache->cached = BTRFS_CACHE_FINISHED;
1252 	cache->free_space_ctl->free_space = free;
1253 	cache->zone_unusable = unusable;
1254 
1255 	/* Should not have any excluded extents. Just in case, though */
1256 	btrfs_free_excluded_extents(cache);
1257 }
1258 
1259 void btrfs_redirty_list_add(struct btrfs_transaction *trans,
1260 			    struct extent_buffer *eb)
1261 {
1262 	struct btrfs_fs_info *fs_info = eb->fs_info;
1263 
1264 	if (!btrfs_is_zoned(fs_info) ||
1265 	    btrfs_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN) ||
1266 	    !list_empty(&eb->release_list))
1267 		return;
1268 
1269 	set_extent_buffer_dirty(eb);
1270 	set_extent_bits_nowait(&trans->dirty_pages, eb->start,
1271 			       eb->start + eb->len - 1, EXTENT_DIRTY);
1272 	memzero_extent_buffer(eb, 0, eb->len);
1273 	set_bit(EXTENT_BUFFER_NO_CHECK, &eb->bflags);
1274 
1275 	spin_lock(&trans->releasing_ebs_lock);
1276 	list_add_tail(&eb->release_list, &trans->releasing_ebs);
1277 	spin_unlock(&trans->releasing_ebs_lock);
1278 	atomic_inc(&eb->refs);
1279 }
1280 
1281 void btrfs_free_redirty_list(struct btrfs_transaction *trans)
1282 {
1283 	spin_lock(&trans->releasing_ebs_lock);
1284 	while (!list_empty(&trans->releasing_ebs)) {
1285 		struct extent_buffer *eb;
1286 
1287 		eb = list_first_entry(&trans->releasing_ebs,
1288 				      struct extent_buffer, release_list);
1289 		list_del_init(&eb->release_list);
1290 		free_extent_buffer(eb);
1291 	}
1292 	spin_unlock(&trans->releasing_ebs_lock);
1293 }
1294 
1295 bool btrfs_use_zone_append(struct btrfs_inode *inode, u64 start)
1296 {
1297 	struct btrfs_fs_info *fs_info = inode->root->fs_info;
1298 	struct btrfs_block_group *cache;
1299 	bool ret = false;
1300 
1301 	if (!btrfs_is_zoned(fs_info))
1302 		return false;
1303 
1304 	if (!is_data_inode(&inode->vfs_inode))
1305 		return false;
1306 
1307 	cache = btrfs_lookup_block_group(fs_info, start);
1308 	ASSERT(cache);
1309 	if (!cache)
1310 		return false;
1311 
1312 	ret = cache->seq_zone;
1313 	btrfs_put_block_group(cache);
1314 
1315 	return ret;
1316 }
1317 
1318 void btrfs_record_physical_zoned(struct inode *inode, u64 file_offset,
1319 				 struct bio *bio)
1320 {
1321 	struct btrfs_ordered_extent *ordered;
1322 	const u64 physical = bio->bi_iter.bi_sector << SECTOR_SHIFT;
1323 
1324 	if (bio_op(bio) != REQ_OP_ZONE_APPEND)
1325 		return;
1326 
1327 	ordered = btrfs_lookup_ordered_extent(BTRFS_I(inode), file_offset);
1328 	if (WARN_ON(!ordered))
1329 		return;
1330 
1331 	ordered->physical = physical;
1332 	ordered->bdev = bio->bi_bdev;
1333 
1334 	btrfs_put_ordered_extent(ordered);
1335 }
1336 
1337 void btrfs_rewrite_logical_zoned(struct btrfs_ordered_extent *ordered)
1338 {
1339 	struct btrfs_inode *inode = BTRFS_I(ordered->inode);
1340 	struct btrfs_fs_info *fs_info = inode->root->fs_info;
1341 	struct extent_map_tree *em_tree;
1342 	struct extent_map *em;
1343 	struct btrfs_ordered_sum *sum;
1344 	u64 orig_logical = ordered->disk_bytenr;
1345 	u64 *logical = NULL;
1346 	int nr, stripe_len;
1347 
1348 	/* Zoned devices should not have partitions. So, we can assume it is 0 */
1349 	ASSERT(!bdev_is_partition(ordered->bdev));
1350 	if (WARN_ON(!ordered->bdev))
1351 		return;
1352 
1353 	if (WARN_ON(btrfs_rmap_block(fs_info, orig_logical, ordered->bdev,
1354 				     ordered->physical, &logical, &nr,
1355 				     &stripe_len)))
1356 		goto out;
1357 
1358 	WARN_ON(nr != 1);
1359 
1360 	if (orig_logical == *logical)
1361 		goto out;
1362 
1363 	ordered->disk_bytenr = *logical;
1364 
1365 	em_tree = &inode->extent_tree;
1366 	write_lock(&em_tree->lock);
1367 	em = search_extent_mapping(em_tree, ordered->file_offset,
1368 				   ordered->num_bytes);
1369 	em->block_start = *logical;
1370 	free_extent_map(em);
1371 	write_unlock(&em_tree->lock);
1372 
1373 	list_for_each_entry(sum, &ordered->list, list) {
1374 		if (*logical < orig_logical)
1375 			sum->bytenr -= orig_logical - *logical;
1376 		else
1377 			sum->bytenr += *logical - orig_logical;
1378 	}
1379 
1380 out:
1381 	kfree(logical);
1382 }
1383 
1384 bool btrfs_check_meta_write_pointer(struct btrfs_fs_info *fs_info,
1385 				    struct extent_buffer *eb,
1386 				    struct btrfs_block_group **cache_ret)
1387 {
1388 	struct btrfs_block_group *cache;
1389 	bool ret = true;
1390 
1391 	if (!btrfs_is_zoned(fs_info))
1392 		return true;
1393 
1394 	cache = *cache_ret;
1395 
1396 	if (cache && (eb->start < cache->start ||
1397 		      cache->start + cache->length <= eb->start)) {
1398 		btrfs_put_block_group(cache);
1399 		cache = NULL;
1400 		*cache_ret = NULL;
1401 	}
1402 
1403 	if (!cache)
1404 		cache = btrfs_lookup_block_group(fs_info, eb->start);
1405 
1406 	if (cache) {
1407 		if (cache->meta_write_pointer != eb->start) {
1408 			btrfs_put_block_group(cache);
1409 			cache = NULL;
1410 			ret = false;
1411 		} else {
1412 			cache->meta_write_pointer = eb->start + eb->len;
1413 		}
1414 
1415 		*cache_ret = cache;
1416 	}
1417 
1418 	return ret;
1419 }
1420 
1421 void btrfs_revert_meta_write_pointer(struct btrfs_block_group *cache,
1422 				     struct extent_buffer *eb)
1423 {
1424 	if (!btrfs_is_zoned(eb->fs_info) || !cache)
1425 		return;
1426 
1427 	ASSERT(cache->meta_write_pointer == eb->start + eb->len);
1428 	cache->meta_write_pointer = eb->start;
1429 }
1430 
1431 int btrfs_zoned_issue_zeroout(struct btrfs_device *device, u64 physical, u64 length)
1432 {
1433 	if (!btrfs_dev_is_sequential(device, physical))
1434 		return -EOPNOTSUPP;
1435 
1436 	return blkdev_issue_zeroout(device->bdev, physical >> SECTOR_SHIFT,
1437 				    length >> SECTOR_SHIFT, GFP_NOFS, 0);
1438 }
1439 
1440 static int read_zone_info(struct btrfs_fs_info *fs_info, u64 logical,
1441 			  struct blk_zone *zone)
1442 {
1443 	struct btrfs_bio *bbio = NULL;
1444 	u64 mapped_length = PAGE_SIZE;
1445 	unsigned int nofs_flag;
1446 	int nmirrors;
1447 	int i, ret;
1448 
1449 	ret = btrfs_map_sblock(fs_info, BTRFS_MAP_GET_READ_MIRRORS, logical,
1450 			       &mapped_length, &bbio);
1451 	if (ret || !bbio || mapped_length < PAGE_SIZE) {
1452 		btrfs_put_bbio(bbio);
1453 		return -EIO;
1454 	}
1455 
1456 	if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK)
1457 		return -EINVAL;
1458 
1459 	nofs_flag = memalloc_nofs_save();
1460 	nmirrors = (int)bbio->num_stripes;
1461 	for (i = 0; i < nmirrors; i++) {
1462 		u64 physical = bbio->stripes[i].physical;
1463 		struct btrfs_device *dev = bbio->stripes[i].dev;
1464 
1465 		/* Missing device */
1466 		if (!dev->bdev)
1467 			continue;
1468 
1469 		ret = btrfs_get_dev_zone(dev, physical, zone);
1470 		/* Failing device */
1471 		if (ret == -EIO || ret == -EOPNOTSUPP)
1472 			continue;
1473 		break;
1474 	}
1475 	memalloc_nofs_restore(nofs_flag);
1476 
1477 	return ret;
1478 }
1479 
1480 /*
1481  * Synchronize write pointer in a zone at @physical_start on @tgt_dev, by
1482  * filling zeros between @physical_pos to a write pointer of dev-replace
1483  * source device.
1484  */
1485 int btrfs_sync_zone_write_pointer(struct btrfs_device *tgt_dev, u64 logical,
1486 				    u64 physical_start, u64 physical_pos)
1487 {
1488 	struct btrfs_fs_info *fs_info = tgt_dev->fs_info;
1489 	struct blk_zone zone;
1490 	u64 length;
1491 	u64 wp;
1492 	int ret;
1493 
1494 	if (!btrfs_dev_is_sequential(tgt_dev, physical_pos))
1495 		return 0;
1496 
1497 	ret = read_zone_info(fs_info, logical, &zone);
1498 	if (ret)
1499 		return ret;
1500 
1501 	wp = physical_start + ((zone.wp - zone.start) << SECTOR_SHIFT);
1502 
1503 	if (physical_pos == wp)
1504 		return 0;
1505 
1506 	if (physical_pos > wp)
1507 		return -EUCLEAN;
1508 
1509 	length = wp - physical_pos;
1510 	return btrfs_zoned_issue_zeroout(tgt_dev, physical_pos, length);
1511 }
1512 
1513 struct btrfs_device *btrfs_zoned_get_device(struct btrfs_fs_info *fs_info,
1514 					    u64 logical, u64 length)
1515 {
1516 	struct btrfs_device *device;
1517 	struct extent_map *em;
1518 	struct map_lookup *map;
1519 
1520 	em = btrfs_get_chunk_map(fs_info, logical, length);
1521 	if (IS_ERR(em))
1522 		return ERR_CAST(em);
1523 
1524 	map = em->map_lookup;
1525 	/* We only support single profile for now */
1526 	ASSERT(map->num_stripes == 1);
1527 	device = map->stripes[0].dev;
1528 
1529 	free_extent_map(em);
1530 
1531 	return device;
1532 }
1533