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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/rbtree.h>
15#include <linux/blkdev.h>
16#include <linux/blk-mq.h>
17#include <linux/mm.h>
18#include <linux/vmalloc.h>
19#include <linux/sched/mm.h>
20
21#include "blk.h"
22
23static inline sector_t blk_zone_start(struct request_queue *q,
24 sector_t sector)
25{
26 sector_t zone_mask = blk_queue_zone_sectors(q) - 1;
27
28 return sector & ~zone_mask;
29}
30
31/*
32 * Return true if a request is a write requests that needs zone write locking.
33 */
34bool blk_req_needs_zone_write_lock(struct request *rq)
35{
36 if (!rq->q->seq_zones_wlock)
37 return false;
38
39 if (blk_rq_is_passthrough(rq))
40 return false;
41
42 switch (req_op(rq)) {
43 case REQ_OP_WRITE_ZEROES:
44 case REQ_OP_WRITE_SAME:
45 case REQ_OP_WRITE:
46 return blk_rq_zone_is_seq(rq);
47 default:
48 return false;
49 }
50}
51EXPORT_SYMBOL_GPL(blk_req_needs_zone_write_lock);
52
53void __blk_req_zone_write_lock(struct request *rq)
54{
55 if (WARN_ON_ONCE(test_and_set_bit(blk_rq_zone_no(rq),
56 rq->q->seq_zones_wlock)))
57 return;
58
59 WARN_ON_ONCE(rq->rq_flags & RQF_ZONE_WRITE_LOCKED);
60 rq->rq_flags |= RQF_ZONE_WRITE_LOCKED;
61}
62EXPORT_SYMBOL_GPL(__blk_req_zone_write_lock);
63
64void __blk_req_zone_write_unlock(struct request *rq)
65{
66 rq->rq_flags &= ~RQF_ZONE_WRITE_LOCKED;
67 if (rq->q->seq_zones_wlock)
68 WARN_ON_ONCE(!test_and_clear_bit(blk_rq_zone_no(rq),
69 rq->q->seq_zones_wlock));
70}
71EXPORT_SYMBOL_GPL(__blk_req_zone_write_unlock);
72
73static inline unsigned int __blkdev_nr_zones(struct request_queue *q,
74 sector_t nr_sectors)
75{
76 sector_t zone_sectors = blk_queue_zone_sectors(q);
77
78 return (nr_sectors + zone_sectors - 1) >> ilog2(zone_sectors);
79}
80
81/**
82 * blkdev_nr_zones - Get number of zones
83 * @bdev: Target block device
84 *
85 * Description:
86 * Return the total number of zones of a zoned block device.
87 * For a regular block device, the number of zones is always 0.
88 */
89unsigned int blkdev_nr_zones(struct block_device *bdev)
90{
91 struct request_queue *q = bdev_get_queue(bdev);
92
93 if (!blk_queue_is_zoned(q))
94 return 0;
95
96 return __blkdev_nr_zones(q, bdev->bd_part->nr_sects);
97}
98EXPORT_SYMBOL_GPL(blkdev_nr_zones);
99
100/*
101 * Check that a zone report belongs to this partition, and if yes, fix its start
102 * sector and write pointer and return true. Return false otherwise.
103 */
104static bool blkdev_report_zone(struct block_device *bdev, struct blk_zone *rep)
105{
106 sector_t offset = get_start_sect(bdev);
107
108 if (rep->start < offset)
109 return false;
110
111 rep->start -= offset;
112 if (rep->start + rep->len > bdev->bd_part->nr_sects)
113 return false;
114
115 if (rep->type == BLK_ZONE_TYPE_CONVENTIONAL)
116 rep->wp = rep->start + rep->len;
117 else
118 rep->wp -= offset;
119 return true;
120}
121
122static int blk_report_zones(struct gendisk *disk, sector_t sector,
123 struct blk_zone *zones, unsigned int *nr_zones)
124{
125 struct request_queue *q = disk->queue;
126 unsigned int z = 0, n, nrz = *nr_zones;
127 sector_t capacity = get_capacity(disk);
128 int ret;
129
130 while (z < nrz && sector < capacity) {
131 n = nrz - z;
132 ret = disk->fops->report_zones(disk, sector, &zones[z], &n);
133 if (ret)
134 return ret;
135 if (!n)
136 break;
137 sector += blk_queue_zone_sectors(q) * n;
138 z += n;
139 }
140
141 WARN_ON(z > *nr_zones);
142 *nr_zones = z;
143
144 return 0;
145}
146
147/**
148 * blkdev_report_zones - Get zones information
149 * @bdev: Target block device
150 * @sector: Sector from which to report zones
151 * @zones: Array of zone structures where to return the zones information
152 * @nr_zones: Number of zone structures in the zone array
153 *
154 * Description:
155 * Get zone information starting from the zone containing @sector.
156 * The number of zone information reported may be less than the number
157 * requested by @nr_zones. The number of zones actually reported is
158 * returned in @nr_zones.
159 * The caller must use memalloc_noXX_save/restore() calls to control
160 * memory allocations done within this function (zone array and command
161 * buffer allocation by the device driver).
162 */
163int blkdev_report_zones(struct block_device *bdev, sector_t sector,
164 struct blk_zone *zones, unsigned int *nr_zones)
165{
166 struct request_queue *q = bdev_get_queue(bdev);
167 unsigned int i, nrz;
168 int ret;
169
170 if (!blk_queue_is_zoned(q))
171 return -EOPNOTSUPP;
172
173 /*
174 * A block device that advertized itself as zoned must have a
175 * report_zones method. If it does not have one defined, the device
176 * driver has a bug. So warn about that.
177 */
178 if (WARN_ON_ONCE(!bdev->bd_disk->fops->report_zones))
179 return -EOPNOTSUPP;
180
181 if (!*nr_zones || sector >= bdev->bd_part->nr_sects) {
182 *nr_zones = 0;
183 return 0;
184 }
185
186 nrz = min(*nr_zones,
187 __blkdev_nr_zones(q, bdev->bd_part->nr_sects - sector));
188 ret = blk_report_zones(bdev->bd_disk, get_start_sect(bdev) + sector,
189 zones, &nrz);
190 if (ret)
191 return ret;
192
193 for (i = 0; i < nrz; i++) {
194 if (!blkdev_report_zone(bdev, zones))
195 break;
196 zones++;
197 }
198
199 *nr_zones = i;
200
201 return 0;
202}
203EXPORT_SYMBOL_GPL(blkdev_report_zones);
204
205/*
206 * Special case of zone reset operation to reset all zones in one command,
207 * useful for applications like mkfs.
208 */
209static int __blkdev_reset_all_zones(struct block_device *bdev, gfp_t gfp_mask)
210{
211 struct bio *bio = bio_alloc(gfp_mask, 0);
212 int ret;
213
214 /* across the zones operations, don't need any sectors */
215 bio_set_dev(bio, bdev);
216 bio_set_op_attrs(bio, REQ_OP_ZONE_RESET_ALL, 0);
217
218 ret = submit_bio_wait(bio);
219 bio_put(bio);
220
221 return ret;
222}
223
224static inline bool blkdev_allow_reset_all_zones(struct block_device *bdev,
225 sector_t nr_sectors)
226{
227 if (!blk_queue_zone_resetall(bdev_get_queue(bdev)))
228 return false;
229
230 if (nr_sectors != part_nr_sects_read(bdev->bd_part))
231 return false;
232 /*
233 * REQ_OP_ZONE_RESET_ALL can be executed only if the block device is
234 * the entire disk, that is, if the blocks device start offset is 0 and
235 * its capacity is the same as the entire disk.
236 */
237 return get_start_sect(bdev) == 0 &&
238 part_nr_sects_read(bdev->bd_part) == get_capacity(bdev->bd_disk);
239}
240
241/**
242 * blkdev_reset_zones - Reset zones write pointer
243 * @bdev: Target block device
244 * @sector: Start sector of the first zone to reset
245 * @nr_sectors: Number of sectors, at least the length of one zone
246 * @gfp_mask: Memory allocation flags (for bio_alloc)
247 *
248 * Description:
249 * Reset the write pointer of the zones contained in the range
250 * @sector..@sector+@nr_sectors. Specifying the entire disk sector range
251 * is valid, but the specified range should not contain conventional zones.
252 */
253int blkdev_reset_zones(struct block_device *bdev,
254 sector_t sector, sector_t nr_sectors,
255 gfp_t gfp_mask)
256{
257 struct request_queue *q = bdev_get_queue(bdev);
258 sector_t zone_sectors;
259 sector_t end_sector = sector + nr_sectors;
260 struct bio *bio = NULL;
261 struct blk_plug plug;
262 int ret;
263
264 if (!blk_queue_is_zoned(q))
265 return -EOPNOTSUPP;
266
267 if (bdev_read_only(bdev))
268 return -EPERM;
269
270 if (!nr_sectors || end_sector > bdev->bd_part->nr_sects)
271 /* Out of range */
272 return -EINVAL;
273
274 if (blkdev_allow_reset_all_zones(bdev, nr_sectors))
275 return __blkdev_reset_all_zones(bdev, gfp_mask);
276
277 /* Check alignment (handle eventual smaller last zone) */
278 zone_sectors = blk_queue_zone_sectors(q);
279 if (sector & (zone_sectors - 1))
280 return -EINVAL;
281
282 if ((nr_sectors & (zone_sectors - 1)) &&
283 end_sector != bdev->bd_part->nr_sects)
284 return -EINVAL;
285
286 blk_start_plug(&plug);
287 while (sector < end_sector) {
288
289 bio = blk_next_bio(bio, 0, gfp_mask);
290 bio->bi_iter.bi_sector = sector;
291 bio_set_dev(bio, bdev);
292 bio_set_op_attrs(bio, REQ_OP_ZONE_RESET, 0);
293
294 sector += zone_sectors;
295
296 /* This may take a while, so be nice to others */
297 cond_resched();
298
299 }
300
301 ret = submit_bio_wait(bio);
302 bio_put(bio);
303
304 blk_finish_plug(&plug);
305
306 return ret;
307}
308EXPORT_SYMBOL_GPL(blkdev_reset_zones);
309
310/*
311 * BLKREPORTZONE ioctl processing.
312 * Called from blkdev_ioctl.
313 */
314int blkdev_report_zones_ioctl(struct block_device *bdev, fmode_t mode,
315 unsigned int cmd, unsigned long arg)
316{
317 void __user *argp = (void __user *)arg;
318 struct request_queue *q;
319 struct blk_zone_report rep;
320 struct blk_zone *zones;
321 int ret;
322
323 if (!argp)
324 return -EINVAL;
325
326 q = bdev_get_queue(bdev);
327 if (!q)
328 return -ENXIO;
329
330 if (!blk_queue_is_zoned(q))
331 return -ENOTTY;
332
333 if (!capable(CAP_SYS_ADMIN))
334 return -EACCES;
335
336 if (copy_from_user(&rep, argp, sizeof(struct blk_zone_report)))
337 return -EFAULT;
338
339 if (!rep.nr_zones)
340 return -EINVAL;
341
342 rep.nr_zones = min(blkdev_nr_zones(bdev), rep.nr_zones);
343
344 zones = kvmalloc_array(rep.nr_zones, sizeof(struct blk_zone),
345 GFP_KERNEL | __GFP_ZERO);
346 if (!zones)
347 return -ENOMEM;
348
349 ret = blkdev_report_zones(bdev, rep.sector, zones, &rep.nr_zones);
350 if (ret)
351 goto out;
352
353 if (copy_to_user(argp, &rep, sizeof(struct blk_zone_report))) {
354 ret = -EFAULT;
355 goto out;
356 }
357
358 if (rep.nr_zones) {
359 if (copy_to_user(argp + sizeof(struct blk_zone_report), zones,
360 sizeof(struct blk_zone) * rep.nr_zones))
361 ret = -EFAULT;
362 }
363
364 out:
365 kvfree(zones);
366
367 return ret;
368}
369
370/*
371 * BLKRESETZONE ioctl processing.
372 * Called from blkdev_ioctl.
373 */
374int blkdev_reset_zones_ioctl(struct block_device *bdev, fmode_t mode,
375 unsigned int cmd, unsigned long arg)
376{
377 void __user *argp = (void __user *)arg;
378 struct request_queue *q;
379 struct blk_zone_range zrange;
380
381 if (!argp)
382 return -EINVAL;
383
384 q = bdev_get_queue(bdev);
385 if (!q)
386 return -ENXIO;
387
388 if (!blk_queue_is_zoned(q))
389 return -ENOTTY;
390
391 if (!capable(CAP_SYS_ADMIN))
392 return -EACCES;
393
394 if (!(mode & FMODE_WRITE))
395 return -EBADF;
396
397 if (copy_from_user(&zrange, argp, sizeof(struct blk_zone_range)))
398 return -EFAULT;
399
400 return blkdev_reset_zones(bdev, zrange.sector, zrange.nr_sectors,
401 GFP_KERNEL);
402}
403
404static inline unsigned long *blk_alloc_zone_bitmap(int node,
405 unsigned int nr_zones)
406{
407 return kcalloc_node(BITS_TO_LONGS(nr_zones), sizeof(unsigned long),
408 GFP_NOIO, node);
409}
410
411/*
412 * Allocate an array of struct blk_zone to get nr_zones zone information.
413 * The allocated array may be smaller than nr_zones.
414 */
415static struct blk_zone *blk_alloc_zones(unsigned int *nr_zones)
416{
417 struct blk_zone *zones;
418 size_t nrz = min(*nr_zones, BLK_ZONED_REPORT_MAX_ZONES);
419
420 /*
421 * GFP_KERNEL here is meaningless as the caller task context has
422 * the PF_MEMALLOC_NOIO flag set in blk_revalidate_disk_zones()
423 * with memalloc_noio_save().
424 */
425 zones = kvcalloc(nrz, sizeof(struct blk_zone), GFP_KERNEL);
426 if (!zones) {
427 *nr_zones = 0;
428 return NULL;
429 }
430
431 *nr_zones = nrz;
432
433 return zones;
434}
435
436void blk_queue_free_zone_bitmaps(struct request_queue *q)
437{
438 kfree(q->seq_zones_bitmap);
439 q->seq_zones_bitmap = NULL;
440 kfree(q->seq_zones_wlock);
441 q->seq_zones_wlock = NULL;
442}
443
444/**
445 * blk_revalidate_disk_zones - (re)allocate and initialize zone bitmaps
446 * @disk: Target disk
447 *
448 * Helper function for low-level device drivers to (re) allocate and initialize
449 * a disk request queue zone bitmaps. This functions should normally be called
450 * within the disk ->revalidate method. For BIO based queues, no zone bitmap
451 * is allocated.
452 */
453int blk_revalidate_disk_zones(struct gendisk *disk)
454{
455 struct request_queue *q = disk->queue;
456 unsigned int nr_zones = __blkdev_nr_zones(q, get_capacity(disk));
457 unsigned long *seq_zones_wlock = NULL, *seq_zones_bitmap = NULL;
458 unsigned int i, rep_nr_zones = 0, z = 0, nrz;
459 struct blk_zone *zones = NULL;
460 unsigned int noio_flag;
461 sector_t sector = 0;
462 int ret = 0;
463
464 /*
465 * BIO based queues do not use a scheduler so only q->nr_zones
466 * needs to be updated so that the sysfs exposed value is correct.
467 */
468 if (!queue_is_mq(q)) {
469 q->nr_zones = nr_zones;
470 return 0;
471 }
472
473 /*
474 * Ensure that all memory allocations in this context are done as
475 * if GFP_NOIO was specified.
476 */
477 noio_flag = memalloc_noio_save();
478
479 if (!blk_queue_is_zoned(q) || !nr_zones) {
480 nr_zones = 0;
481 goto update;
482 }
483
484 /* Allocate bitmaps */
485 ret = -ENOMEM;
486 seq_zones_wlock = blk_alloc_zone_bitmap(q->node, nr_zones);
487 if (!seq_zones_wlock)
488 goto out;
489 seq_zones_bitmap = blk_alloc_zone_bitmap(q->node, nr_zones);
490 if (!seq_zones_bitmap)
491 goto out;
492
493 /* Get zone information and initialize seq_zones_bitmap */
494 rep_nr_zones = nr_zones;
495 zones = blk_alloc_zones(&rep_nr_zones);
496 if (!zones)
497 goto out;
498
499 while (z < nr_zones) {
500 nrz = min(nr_zones - z, rep_nr_zones);
501 ret = blk_report_zones(disk, sector, zones, &nrz);
502 if (ret)
503 goto out;
504 if (!nrz)
505 break;
506 for (i = 0; i < nrz; i++) {
507 if (zones[i].type != BLK_ZONE_TYPE_CONVENTIONAL)
508 set_bit(z, seq_zones_bitmap);
509 z++;
510 }
511 sector += nrz * blk_queue_zone_sectors(q);
512 }
513
514 if (WARN_ON(z != nr_zones)) {
515 ret = -EIO;
516 goto out;
517 }
518
519update:
520 /*
521 * Install the new bitmaps, making sure the queue is stopped and
522 * all I/Os are completed (i.e. a scheduler is not referencing the
523 * bitmaps).
524 */
525 blk_mq_freeze_queue(q);
526 q->nr_zones = nr_zones;
527 swap(q->seq_zones_wlock, seq_zones_wlock);
528 swap(q->seq_zones_bitmap, seq_zones_bitmap);
529 blk_mq_unfreeze_queue(q);
530
531out:
532 memalloc_noio_restore(noio_flag);
533
534 kvfree(zones);
535 kfree(seq_zones_wlock);
536 kfree(seq_zones_bitmap);
537
538 if (ret) {
539 pr_warn("%s: failed to revalidate zones\n", disk->disk_name);
540 blk_mq_freeze_queue(q);
541 blk_queue_free_zone_bitmaps(q);
542 blk_mq_unfreeze_queue(q);
543 }
544
545 return ret;
546}
547EXPORT_SYMBOL_GPL(blk_revalidate_disk_zones);
548