1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Zoned block device handling
4 *
5 * Copyright (c) 2015, Hannes Reinecke
6 * Copyright (c) 2015, SUSE Linux GmbH
7 *
8 * Copyright (c) 2016, Damien Le Moal
9 * Copyright (c) 2016, Western Digital
10 */
11
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/blkdev.h>
15#include <linux/blk-mq.h>
16#include <linux/mm.h>
17#include <linux/vmalloc.h>
18#include <linux/sched/mm.h>
19
20#include "blk.h"
21
22#define ZONE_COND_NAME(name) [BLK_ZONE_COND_##name] = #name
23static const char *const zone_cond_name[] = {
24 ZONE_COND_NAME(NOT_WP),
25 ZONE_COND_NAME(EMPTY),
26 ZONE_COND_NAME(IMP_OPEN),
27 ZONE_COND_NAME(EXP_OPEN),
28 ZONE_COND_NAME(CLOSED),
29 ZONE_COND_NAME(READONLY),
30 ZONE_COND_NAME(FULL),
31 ZONE_COND_NAME(OFFLINE),
32};
33#undef ZONE_COND_NAME
34
35/**
36 * blk_zone_cond_str - Return string XXX in BLK_ZONE_COND_XXX.
37 * @zone_cond: BLK_ZONE_COND_XXX.
38 *
39 * Description: Centralize block layer function to convert BLK_ZONE_COND_XXX
40 * into string format. Useful in the debugging and tracing zone conditions. For
41 * invalid BLK_ZONE_COND_XXX it returns string "UNKNOWN".
42 */
43const char *blk_zone_cond_str(enum blk_zone_cond zone_cond)
44{
45 static const char *zone_cond_str = "UNKNOWN";
46
47 if (zone_cond < ARRAY_SIZE(zone_cond_name) && zone_cond_name[zone_cond])
48 zone_cond_str = zone_cond_name[zone_cond];
49
50 return zone_cond_str;
51}
52EXPORT_SYMBOL_GPL(blk_zone_cond_str);
53
54/*
55 * Return true if a request is a write requests that needs zone write locking.
56 */
57bool blk_req_needs_zone_write_lock(struct request *rq)
58{
59 if (!rq->q->disk->seq_zones_wlock)
60 return false;
61
62 return blk_rq_is_seq_zoned_write(rq);
63}
64EXPORT_SYMBOL_GPL(blk_req_needs_zone_write_lock);
65
66bool blk_req_zone_write_trylock(struct request *rq)
67{
68 unsigned int zno = blk_rq_zone_no(rq);
69
70 if (test_and_set_bit(nr: zno, addr: rq->q->disk->seq_zones_wlock))
71 return false;
72
73 WARN_ON_ONCE(rq->rq_flags & RQF_ZONE_WRITE_LOCKED);
74 rq->rq_flags |= RQF_ZONE_WRITE_LOCKED;
75
76 return true;
77}
78EXPORT_SYMBOL_GPL(blk_req_zone_write_trylock);
79
80void __blk_req_zone_write_lock(struct request *rq)
81{
82 if (WARN_ON_ONCE(test_and_set_bit(blk_rq_zone_no(rq),
83 rq->q->disk->seq_zones_wlock)))
84 return;
85
86 WARN_ON_ONCE(rq->rq_flags & RQF_ZONE_WRITE_LOCKED);
87 rq->rq_flags |= RQF_ZONE_WRITE_LOCKED;
88}
89EXPORT_SYMBOL_GPL(__blk_req_zone_write_lock);
90
91void __blk_req_zone_write_unlock(struct request *rq)
92{
93 rq->rq_flags &= ~RQF_ZONE_WRITE_LOCKED;
94 if (rq->q->disk->seq_zones_wlock)
95 WARN_ON_ONCE(!test_and_clear_bit(blk_rq_zone_no(rq),
96 rq->q->disk->seq_zones_wlock));
97}
98EXPORT_SYMBOL_GPL(__blk_req_zone_write_unlock);
99
100/**
101 * bdev_nr_zones - Get number of zones
102 * @bdev: Target device
103 *
104 * Return the total number of zones of a zoned block device. For a block
105 * device without zone capabilities, the number of zones is always 0.
106 */
107unsigned int bdev_nr_zones(struct block_device *bdev)
108{
109 sector_t zone_sectors = bdev_zone_sectors(bdev);
110
111 if (!bdev_is_zoned(bdev))
112 return 0;
113 return (bdev_nr_sectors(bdev) + zone_sectors - 1) >>
114 ilog2(zone_sectors);
115}
116EXPORT_SYMBOL_GPL(bdev_nr_zones);
117
118/**
119 * blkdev_report_zones - Get zones information
120 * @bdev: Target block device
121 * @sector: Sector from which to report zones
122 * @nr_zones: Maximum number of zones to report
123 * @cb: Callback function called for each reported zone
124 * @data: Private data for the callback
125 *
126 * Description:
127 * Get zone information starting from the zone containing @sector for at most
128 * @nr_zones, and call @cb for each zone reported by the device.
129 * To report all zones in a device starting from @sector, the BLK_ALL_ZONES
130 * constant can be passed to @nr_zones.
131 * Returns the number of zones reported by the device, or a negative errno
132 * value in case of failure.
133 *
134 * Note: The caller must use memalloc_noXX_save/restore() calls to control
135 * memory allocations done within this function.
136 */
137int blkdev_report_zones(struct block_device *bdev, sector_t sector,
138 unsigned int nr_zones, report_zones_cb cb, void *data)
139{
140 struct gendisk *disk = bdev->bd_disk;
141 sector_t capacity = get_capacity(disk);
142
143 if (!bdev_is_zoned(bdev) || WARN_ON_ONCE(!disk->fops->report_zones))
144 return -EOPNOTSUPP;
145
146 if (!nr_zones || sector >= capacity)
147 return 0;
148
149 return disk->fops->report_zones(disk, sector, nr_zones, cb, data);
150}
151EXPORT_SYMBOL_GPL(blkdev_report_zones);
152
153static inline unsigned long *blk_alloc_zone_bitmap(int node,
154 unsigned int nr_zones)
155{
156 return kcalloc_node(BITS_TO_LONGS(nr_zones), size: sizeof(unsigned long),
157 GFP_NOIO, node);
158}
159
160static int blk_zone_need_reset_cb(struct blk_zone *zone, unsigned int idx,
161 void *data)
162{
163 /*
164 * For an all-zones reset, ignore conventional, empty, read-only
165 * and offline zones.
166 */
167 switch (zone->cond) {
168 case BLK_ZONE_COND_NOT_WP:
169 case BLK_ZONE_COND_EMPTY:
170 case BLK_ZONE_COND_READONLY:
171 case BLK_ZONE_COND_OFFLINE:
172 return 0;
173 default:
174 set_bit(nr: idx, addr: (unsigned long *)data);
175 return 0;
176 }
177}
178
179static int blkdev_zone_reset_all_emulated(struct block_device *bdev)
180{
181 struct gendisk *disk = bdev->bd_disk;
182 sector_t capacity = bdev_nr_sectors(bdev);
183 sector_t zone_sectors = bdev_zone_sectors(bdev);
184 unsigned long *need_reset;
185 struct bio *bio = NULL;
186 sector_t sector = 0;
187 int ret;
188
189 need_reset = blk_alloc_zone_bitmap(node: disk->queue->node, nr_zones: disk->nr_zones);
190 if (!need_reset)
191 return -ENOMEM;
192
193 ret = disk->fops->report_zones(disk, 0, disk->nr_zones,
194 blk_zone_need_reset_cb, need_reset);
195 if (ret < 0)
196 goto out_free_need_reset;
197
198 ret = 0;
199 while (sector < capacity) {
200 if (!test_bit(disk_zone_no(disk, sector), need_reset)) {
201 sector += zone_sectors;
202 continue;
203 }
204
205 bio = blk_next_bio(bio, bdev, nr_pages: 0, opf: REQ_OP_ZONE_RESET | REQ_SYNC,
206 GFP_KERNEL);
207 bio->bi_iter.bi_sector = sector;
208 sector += zone_sectors;
209
210 /* This may take a while, so be nice to others */
211 cond_resched();
212 }
213
214 if (bio) {
215 ret = submit_bio_wait(bio);
216 bio_put(bio);
217 }
218
219out_free_need_reset:
220 kfree(objp: need_reset);
221 return ret;
222}
223
224static int blkdev_zone_reset_all(struct block_device *bdev)
225{
226 struct bio bio;
227
228 bio_init(bio: &bio, bdev, NULL, max_vecs: 0, opf: REQ_OP_ZONE_RESET_ALL | REQ_SYNC);
229 return submit_bio_wait(bio: &bio);
230}
231
232/**
233 * blkdev_zone_mgmt - Execute a zone management operation on a range of zones
234 * @bdev: Target block device
235 * @op: Operation to be performed on the zones
236 * @sector: Start sector of the first zone to operate on
237 * @nr_sectors: Number of sectors, should be at least the length of one zone and
238 * must be zone size aligned.
239 *
240 * Description:
241 * Perform the specified operation on the range of zones specified by
242 * @sector..@sector+@nr_sectors. Specifying the entire disk sector range
243 * is valid, but the specified range should not contain conventional zones.
244 * The operation to execute on each zone can be a zone reset, open, close
245 * or finish request.
246 */
247int blkdev_zone_mgmt(struct block_device *bdev, enum req_op op,
248 sector_t sector, sector_t nr_sectors)
249{
250 struct request_queue *q = bdev_get_queue(bdev);
251 sector_t zone_sectors = bdev_zone_sectors(bdev);
252 sector_t capacity = bdev_nr_sectors(bdev);
253 sector_t end_sector = sector + nr_sectors;
254 struct bio *bio = NULL;
255 int ret = 0;
256
257 if (!bdev_is_zoned(bdev))
258 return -EOPNOTSUPP;
259
260 if (bdev_read_only(bdev))
261 return -EPERM;
262
263 if (!op_is_zone_mgmt(op))
264 return -EOPNOTSUPP;
265
266 if (end_sector <= sector || end_sector > capacity)
267 /* Out of range */
268 return -EINVAL;
269
270 /* Check alignment (handle eventual smaller last zone) */
271 if (!bdev_is_zone_start(bdev, sector))
272 return -EINVAL;
273
274 if (!bdev_is_zone_start(bdev, sector: nr_sectors) && end_sector != capacity)
275 return -EINVAL;
276
277 /*
278 * In the case of a zone reset operation over all zones,
279 * REQ_OP_ZONE_RESET_ALL can be used with devices supporting this
280 * command. For other devices, we emulate this command behavior by
281 * identifying the zones needing a reset.
282 */
283 if (op == REQ_OP_ZONE_RESET && sector == 0 && nr_sectors == capacity) {
284 if (!blk_queue_zone_resetall(q))
285 return blkdev_zone_reset_all_emulated(bdev);
286 return blkdev_zone_reset_all(bdev);
287 }
288
289 while (sector < end_sector) {
290 bio = blk_next_bio(bio, bdev, nr_pages: 0, opf: op | REQ_SYNC, GFP_KERNEL);
291 bio->bi_iter.bi_sector = sector;
292 sector += zone_sectors;
293
294 /* This may take a while, so be nice to others */
295 cond_resched();
296 }
297
298 ret = submit_bio_wait(bio);
299 bio_put(bio);
300
301 return ret;
302}
303EXPORT_SYMBOL_GPL(blkdev_zone_mgmt);
304
305struct zone_report_args {
306 struct blk_zone __user *zones;
307};
308
309static int blkdev_copy_zone_to_user(struct blk_zone *zone, unsigned int idx,
310 void *data)
311{
312 struct zone_report_args *args = data;
313
314 if (copy_to_user(to: &args->zones[idx], from: zone, n: sizeof(struct blk_zone)))
315 return -EFAULT;
316 return 0;
317}
318
319/*
320 * BLKREPORTZONE ioctl processing.
321 * Called from blkdev_ioctl.
322 */
323int blkdev_report_zones_ioctl(struct block_device *bdev, unsigned int cmd,
324 unsigned long arg)
325{
326 void __user *argp = (void __user *)arg;
327 struct zone_report_args args;
328 struct blk_zone_report rep;
329 int ret;
330
331 if (!argp)
332 return -EINVAL;
333
334 if (!bdev_is_zoned(bdev))
335 return -ENOTTY;
336
337 if (copy_from_user(to: &rep, from: argp, n: sizeof(struct blk_zone_report)))
338 return -EFAULT;
339
340 if (!rep.nr_zones)
341 return -EINVAL;
342
343 args.zones = argp + sizeof(struct blk_zone_report);
344 ret = blkdev_report_zones(bdev, rep.sector, rep.nr_zones,
345 blkdev_copy_zone_to_user, &args);
346 if (ret < 0)
347 return ret;
348
349 rep.nr_zones = ret;
350 rep.flags = BLK_ZONE_REP_CAPACITY;
351 if (copy_to_user(to: argp, from: &rep, n: sizeof(struct blk_zone_report)))
352 return -EFAULT;
353 return 0;
354}
355
356static int blkdev_truncate_zone_range(struct block_device *bdev,
357 blk_mode_t mode, const struct blk_zone_range *zrange)
358{
359 loff_t start, end;
360
361 if (zrange->sector + zrange->nr_sectors <= zrange->sector ||
362 zrange->sector + zrange->nr_sectors > get_capacity(disk: bdev->bd_disk))
363 /* Out of range */
364 return -EINVAL;
365
366 start = zrange->sector << SECTOR_SHIFT;
367 end = ((zrange->sector + zrange->nr_sectors) << SECTOR_SHIFT) - 1;
368
369 return truncate_bdev_range(bdev, mode, lstart: start, lend: end);
370}
371
372/*
373 * BLKRESETZONE, BLKOPENZONE, BLKCLOSEZONE and BLKFINISHZONE ioctl processing.
374 * Called from blkdev_ioctl.
375 */
376int blkdev_zone_mgmt_ioctl(struct block_device *bdev, blk_mode_t mode,
377 unsigned int cmd, unsigned long arg)
378{
379 void __user *argp = (void __user *)arg;
380 struct blk_zone_range zrange;
381 enum req_op op;
382 int ret;
383
384 if (!argp)
385 return -EINVAL;
386
387 if (!bdev_is_zoned(bdev))
388 return -ENOTTY;
389
390 if (!(mode & BLK_OPEN_WRITE))
391 return -EBADF;
392
393 if (copy_from_user(to: &zrange, from: argp, n: sizeof(struct blk_zone_range)))
394 return -EFAULT;
395
396 switch (cmd) {
397 case BLKRESETZONE:
398 op = REQ_OP_ZONE_RESET;
399
400 /* Invalidate the page cache, including dirty pages. */
401 filemap_invalidate_lock(mapping: bdev->bd_inode->i_mapping);
402 ret = blkdev_truncate_zone_range(bdev, mode, zrange: &zrange);
403 if (ret)
404 goto fail;
405 break;
406 case BLKOPENZONE:
407 op = REQ_OP_ZONE_OPEN;
408 break;
409 case BLKCLOSEZONE:
410 op = REQ_OP_ZONE_CLOSE;
411 break;
412 case BLKFINISHZONE:
413 op = REQ_OP_ZONE_FINISH;
414 break;
415 default:
416 return -ENOTTY;
417 }
418
419 ret = blkdev_zone_mgmt(bdev, op, zrange.sector, zrange.nr_sectors);
420
421fail:
422 if (cmd == BLKRESETZONE)
423 filemap_invalidate_unlock(mapping: bdev->bd_inode->i_mapping);
424
425 return ret;
426}
427
428void disk_free_zone_bitmaps(struct gendisk *disk)
429{
430 kfree(objp: disk->conv_zones_bitmap);
431 disk->conv_zones_bitmap = NULL;
432 kfree(objp: disk->seq_zones_wlock);
433 disk->seq_zones_wlock = NULL;
434}
435
436struct blk_revalidate_zone_args {
437 struct gendisk *disk;
438 unsigned long *conv_zones_bitmap;
439 unsigned long *seq_zones_wlock;
440 unsigned int nr_zones;
441 sector_t sector;
442};
443
444/*
445 * Helper function to check the validity of zones of a zoned block device.
446 */
447static int blk_revalidate_zone_cb(struct blk_zone *zone, unsigned int idx,
448 void *data)
449{
450 struct blk_revalidate_zone_args *args = data;
451 struct gendisk *disk = args->disk;
452 struct request_queue *q = disk->queue;
453 sector_t capacity = get_capacity(disk);
454 sector_t zone_sectors = q->limits.chunk_sectors;
455
456 /* Check for bad zones and holes in the zone report */
457 if (zone->start != args->sector) {
458 pr_warn("%s: Zone gap at sectors %llu..%llu\n",
459 disk->disk_name, args->sector, zone->start);
460 return -ENODEV;
461 }
462
463 if (zone->start >= capacity || !zone->len) {
464 pr_warn("%s: Invalid zone start %llu, length %llu\n",
465 disk->disk_name, zone->start, zone->len);
466 return -ENODEV;
467 }
468
469 /*
470 * All zones must have the same size, with the exception on an eventual
471 * smaller last zone.
472 */
473 if (zone->start + zone->len < capacity) {
474 if (zone->len != zone_sectors) {
475 pr_warn("%s: Invalid zoned device with non constant zone size\n",
476 disk->disk_name);
477 return -ENODEV;
478 }
479 } else if (zone->len > zone_sectors) {
480 pr_warn("%s: Invalid zoned device with larger last zone size\n",
481 disk->disk_name);
482 return -ENODEV;
483 }
484
485 /* Check zone type */
486 switch (zone->type) {
487 case BLK_ZONE_TYPE_CONVENTIONAL:
488 if (!args->conv_zones_bitmap) {
489 args->conv_zones_bitmap =
490 blk_alloc_zone_bitmap(node: q->node, nr_zones: args->nr_zones);
491 if (!args->conv_zones_bitmap)
492 return -ENOMEM;
493 }
494 set_bit(nr: idx, addr: args->conv_zones_bitmap);
495 break;
496 case BLK_ZONE_TYPE_SEQWRITE_REQ:
497 if (!args->seq_zones_wlock) {
498 args->seq_zones_wlock =
499 blk_alloc_zone_bitmap(node: q->node, nr_zones: args->nr_zones);
500 if (!args->seq_zones_wlock)
501 return -ENOMEM;
502 }
503 break;
504 case BLK_ZONE_TYPE_SEQWRITE_PREF:
505 default:
506 pr_warn("%s: Invalid zone type 0x%x at sectors %llu\n",
507 disk->disk_name, (int)zone->type, zone->start);
508 return -ENODEV;
509 }
510
511 args->sector += zone->len;
512 return 0;
513}
514
515/**
516 * blk_revalidate_disk_zones - (re)allocate and initialize zone bitmaps
517 * @disk: Target disk
518 * @update_driver_data: Callback to update driver data on the frozen disk
519 *
520 * Helper function for low-level device drivers to check and (re) allocate and
521 * initialize a disk request queue zone bitmaps. This functions should normally
522 * be called within the disk ->revalidate method for blk-mq based drivers.
523 * Before calling this function, the device driver must already have set the
524 * device zone size (chunk_sector limit) and the max zone append limit.
525 * For BIO based drivers, this function cannot be used. BIO based device drivers
526 * only need to set disk->nr_zones so that the sysfs exposed value is correct.
527 * If the @update_driver_data callback function is not NULL, the callback is
528 * executed with the device request queue frozen after all zones have been
529 * checked.
530 */
531int blk_revalidate_disk_zones(struct gendisk *disk,
532 void (*update_driver_data)(struct gendisk *disk))
533{
534 struct request_queue *q = disk->queue;
535 sector_t zone_sectors = q->limits.chunk_sectors;
536 sector_t capacity = get_capacity(disk);
537 struct blk_revalidate_zone_args args = { };
538 unsigned int noio_flag;
539 int ret;
540
541 if (WARN_ON_ONCE(!blk_queue_is_zoned(q)))
542 return -EIO;
543 if (WARN_ON_ONCE(!queue_is_mq(q)))
544 return -EIO;
545
546 if (!capacity)
547 return -ENODEV;
548
549 /*
550 * Checks that the device driver indicated a valid zone size and that
551 * the max zone append limit is set.
552 */
553 if (!zone_sectors || !is_power_of_2(n: zone_sectors)) {
554 pr_warn("%s: Invalid non power of two zone size (%llu)\n",
555 disk->disk_name, zone_sectors);
556 return -ENODEV;
557 }
558
559 if (!q->limits.max_zone_append_sectors) {
560 pr_warn("%s: Invalid 0 maximum zone append limit\n",
561 disk->disk_name);
562 return -ENODEV;
563 }
564
565 /*
566 * Ensure that all memory allocations in this context are done as if
567 * GFP_NOIO was specified.
568 */
569 args.disk = disk;
570 args.nr_zones = (capacity + zone_sectors - 1) >> ilog2(zone_sectors);
571 noio_flag = memalloc_noio_save();
572 ret = disk->fops->report_zones(disk, 0, UINT_MAX,
573 blk_revalidate_zone_cb, &args);
574 if (!ret) {
575 pr_warn("%s: No zones reported\n", disk->disk_name);
576 ret = -ENODEV;
577 }
578 memalloc_noio_restore(flags: noio_flag);
579
580 /*
581 * If zones where reported, make sure that the entire disk capacity
582 * has been checked.
583 */
584 if (ret > 0 && args.sector != capacity) {
585 pr_warn("%s: Missing zones from sector %llu\n",
586 disk->disk_name, args.sector);
587 ret = -ENODEV;
588 }
589
590 /*
591 * Install the new bitmaps and update nr_zones only once the queue is
592 * stopped and all I/Os are completed (i.e. a scheduler is not
593 * referencing the bitmaps).
594 */
595 blk_mq_freeze_queue(q);
596 if (ret > 0) {
597 disk->nr_zones = args.nr_zones;
598 swap(disk->seq_zones_wlock, args.seq_zones_wlock);
599 swap(disk->conv_zones_bitmap, args.conv_zones_bitmap);
600 if (update_driver_data)
601 update_driver_data(disk);
602 ret = 0;
603 } else {
604 pr_warn("%s: failed to revalidate zones\n", disk->disk_name);
605 disk_free_zone_bitmaps(disk);
606 }
607 blk_mq_unfreeze_queue(q);
608
609 kfree(objp: args.seq_zones_wlock);
610 kfree(objp: args.conv_zones_bitmap);
611 return ret;
612}
613EXPORT_SYMBOL_GPL(blk_revalidate_disk_zones);
614

source code of linux/block/blk-zoned.c