summaryrefslogtreecommitdiff
path: root/block/blk-zoned.c
blob: 14785011e7984cc0a8799da6df034fd3d514a7bc (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
// SPDX-License-Identifier: GPL-2.0
/*
 * Zoned block device handling
 *
 * Copyright (c) 2015, Hannes Reinecke
 * Copyright (c) 2015, SUSE Linux GmbH
 *
 * Copyright (c) 2016, Damien Le Moal
 * Copyright (c) 2016, Western Digital
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/rbtree.h>
#include <linux/blkdev.h>
#include <linux/blk-mq.h>
#include <linux/mm.h>
#include <linux/vmalloc.h>
#include <linux/sched/mm.h>

#include "blk.h"

static inline sector_t blk_zone_start(struct request_queue *q,
				      sector_t sector)
{
	sector_t zone_mask = blk_queue_zone_sectors(q) - 1;

	return sector & ~zone_mask;
}

/*
 * Return true if a request is a write requests that needs zone write locking.
 */
bool blk_req_needs_zone_write_lock(struct request *rq)
{
	if (!rq->q->seq_zones_wlock)
		return false;

	if (blk_rq_is_passthrough(rq))
		return false;

	switch (req_op(rq)) {
	case REQ_OP_WRITE_ZEROES:
	case REQ_OP_WRITE_SAME:
	case REQ_OP_WRITE:
		return blk_rq_zone_is_seq(rq);
	default:
		return false;
	}
}
EXPORT_SYMBOL_GPL(blk_req_needs_zone_write_lock);

void __blk_req_zone_write_lock(struct request *rq)
{
	if (WARN_ON_ONCE(test_and_set_bit(blk_rq_zone_no(rq),
					  rq->q->seq_zones_wlock)))
		return;

	WARN_ON_ONCE(rq->rq_flags & RQF_ZONE_WRITE_LOCKED);
	rq->rq_flags |= RQF_ZONE_WRITE_LOCKED;
}
EXPORT_SYMBOL_GPL(__blk_req_zone_write_lock);

void __blk_req_zone_write_unlock(struct request *rq)
{
	rq->rq_flags &= ~RQF_ZONE_WRITE_LOCKED;
	if (rq->q->seq_zones_wlock)
		WARN_ON_ONCE(!test_and_clear_bit(blk_rq_zone_no(rq),
						 rq->q->seq_zones_wlock));
}
EXPORT_SYMBOL_GPL(__blk_req_zone_write_unlock);

static inline unsigned int __blkdev_nr_zones(struct request_queue *q,
					     sector_t nr_sectors)
{
	sector_t zone_sectors = blk_queue_zone_sectors(q);

	return (nr_sectors + zone_sectors - 1) >> ilog2(zone_sectors);
}

/**
 * blkdev_nr_zones - Get number of zones
 * @bdev:	Target block device
 *
 * Description:
 *    Return the total number of zones of a zoned block device.
 *    For a regular block device, the number of zones is always 0.
 */
unsigned int blkdev_nr_zones(struct block_device *bdev)
{
	struct request_queue *q = bdev_get_queue(bdev);

	if (!blk_queue_is_zoned(q))
		return 0;

	return __blkdev_nr_zones(q, bdev->bd_part->nr_sects);
}
EXPORT_SYMBOL_GPL(blkdev_nr_zones);

/*
 * Check that a zone report belongs to this partition, and if yes, fix its start
 * sector and write pointer and return true. Return false otherwise.
 */
static bool blkdev_report_zone(struct block_device *bdev, struct blk_zone *rep)
{
	sector_t offset = get_start_sect(bdev);

	if (rep->start < offset)
		return false;

	rep->start -= offset;
	if (rep->start + rep->len > bdev->bd_part->nr_sects)
		return false;

	if (rep->type == BLK_ZONE_TYPE_CONVENTIONAL)
		rep->wp = rep->start + rep->len;
	else
		rep->wp -= offset;
	return true;
}

static int blk_report_zones(struct gendisk *disk, sector_t sector,
			    struct blk_zone *zones, unsigned int *nr_zones)
{
	struct request_queue *q = disk->queue;
	unsigned int z = 0, n, nrz = *nr_zones;
	sector_t capacity = get_capacity(disk);
	int ret;

	while (z < nrz && sector < capacity) {
		n = nrz - z;
		ret = disk->fops->report_zones(disk, sector, &zones[z], &n);
		if (ret)
			return ret;
		if (!n)
			break;
		sector += blk_queue_zone_sectors(q) * n;
		z += n;
	}

	WARN_ON(z > *nr_zones);
	*nr_zones = z;

	return 0;
}

/**
 * blkdev_report_zones - Get zones information
 * @bdev:	Target block device
 * @sector:	Sector from which to report zones
 * @zones:	Array of zone structures where to return the zones information
 * @nr_zones:	Number of zone structures in the zone array
 *
 * Description:
 *    Get zone information starting from the zone containing @sector.
 *    The number of zone information reported may be less than the number
 *    requested by @nr_zones. The number of zones actually reported is
 *    returned in @nr_zones.
 *    The caller must use memalloc_noXX_save/restore() calls to control
 *    memory allocations done within this function (zone array and command
 *    buffer allocation by the device driver).
 */
int blkdev_report_zones(struct block_device *bdev, sector_t sector,
			struct blk_zone *zones, unsigned int *nr_zones)
{
	struct request_queue *q = bdev_get_queue(bdev);
	unsigned int i, nrz;
	int ret;

	if (!blk_queue_is_zoned(q))
		return -EOPNOTSUPP;

	/*
	 * A block device that advertized itself as zoned must have a
	 * report_zones method. If it does not have one defined, the device
	 * driver has a bug. So warn about that.
	 */
	if (WARN_ON_ONCE(!bdev->bd_disk->fops->report_zones))
		return -EOPNOTSUPP;

	if (!*nr_zones || sector >= bdev->bd_part->nr_sects) {
		*nr_zones = 0;
		return 0;
	}

	nrz = min(*nr_zones,
		  __blkdev_nr_zones(q, bdev->bd_part->nr_sects - sector));
	ret = blk_report_zones(bdev->bd_disk, get_start_sect(bdev) + sector,
			       zones, &nrz);
	if (ret)
		return ret;

	for (i = 0; i < nrz; i++) {
		if (!blkdev_report_zone(bdev, zones))
			break;
		zones++;
	}

	*nr_zones = i;

	return 0;
}
EXPORT_SYMBOL_GPL(blkdev_report_zones);

static inline bool blkdev_allow_reset_all_zones(struct block_device *bdev,
						sector_t sector,
						sector_t nr_sectors)
{
	if (!blk_queue_zone_resetall(bdev_get_queue(bdev)))
		return false;

	if (sector || nr_sectors != part_nr_sects_read(bdev->bd_part))
		return false;
	/*
	 * REQ_OP_ZONE_RESET_ALL can be executed only if the block device is
	 * the entire disk, that is, if the blocks device start offset is 0 and
	 * its capacity is the same as the entire disk.
	 */
	return get_start_sect(bdev) == 0 &&
	       part_nr_sects_read(bdev->bd_part) == get_capacity(bdev->bd_disk);
}

/**
 * blkdev_reset_zones - Reset zones write pointer
 * @bdev:	Target block device
 * @sector:	Start sector of the first zone to reset
 * @nr_sectors:	Number of sectors, at least the length of one zone
 * @gfp_mask:	Memory allocation flags (for bio_alloc)
 *
 * Description:
 *    Reset the write pointer of the zones contained in the range
 *    @sector..@sector+@nr_sectors. Specifying the entire disk sector range
 *    is valid, but the specified range should not contain conventional zones.
 */
int blkdev_reset_zones(struct block_device *bdev,
		       sector_t sector, sector_t nr_sectors,
		       gfp_t gfp_mask)
{
	struct request_queue *q = bdev_get_queue(bdev);
	sector_t zone_sectors;
	sector_t end_sector = sector + nr_sectors;
	struct bio *bio = NULL;
	int ret;

	if (!blk_queue_is_zoned(q))
		return -EOPNOTSUPP;

	if (bdev_read_only(bdev))
		return -EPERM;

	if (!nr_sectors || end_sector > bdev->bd_part->nr_sects)
		/* Out of range */
		return -EINVAL;

	/* Check alignment (handle eventual smaller last zone) */
	zone_sectors = blk_queue_zone_sectors(q);
	if (sector & (zone_sectors - 1))
		return -EINVAL;

	if ((nr_sectors & (zone_sectors - 1)) &&
	    end_sector != bdev->bd_part->nr_sects)
		return -EINVAL;

	while (sector < end_sector) {
		bio = blk_next_bio(bio, 0, gfp_mask);
		bio_set_dev(bio, bdev);

		/*
		 * Special case for the zone reset operation that reset all
		 * zones, this is useful for applications like mkfs.
		 */
		if (blkdev_allow_reset_all_zones(bdev, sector, nr_sectors)) {
			bio->bi_opf = REQ_OP_ZONE_RESET_ALL;
			break;
		}

		bio->bi_opf = REQ_OP_ZONE_RESET;
		bio->bi_iter.bi_sector = sector;
		sector += zone_sectors;

		/* This may take a while, so be nice to others */
		cond_resched();
	}

	ret = submit_bio_wait(bio);
	bio_put(bio);

	return ret;
}
EXPORT_SYMBOL_GPL(blkdev_reset_zones);

/*
 * BLKREPORTZONE ioctl processing.
 * Called from blkdev_ioctl.
 */
int blkdev_report_zones_ioctl(struct block_device *bdev, fmode_t mode,
			      unsigned int cmd, unsigned long arg)
{
	void __user *argp = (void __user *)arg;
	struct request_queue *q;
	struct blk_zone_report rep;
	struct blk_zone *zones;
	int ret;

	if (!argp)
		return -EINVAL;

	q = bdev_get_queue(bdev);
	if (!q)
		return -ENXIO;

	if (!blk_queue_is_zoned(q))
		return -ENOTTY;

	if (!capable(CAP_SYS_ADMIN))
		return -EACCES;

	if (copy_from_user(&rep, argp, sizeof(struct blk_zone_report)))
		return -EFAULT;

	if (!rep.nr_zones)
		return -EINVAL;

	rep.nr_zones = min(blkdev_nr_zones(bdev), rep.nr_zones);

	zones = kvmalloc_array(rep.nr_zones, sizeof(struct blk_zone),
			       GFP_KERNEL | __GFP_ZERO);
	if (!zones)
		return -ENOMEM;

	ret = blkdev_report_zones(bdev, rep.sector, zones, &rep.nr_zones);
	if (ret)
		goto out;

	if (copy_to_user(argp, &rep, sizeof(struct blk_zone_report))) {
		ret = -EFAULT;
		goto out;
	}

	if (rep.nr_zones) {
		if (copy_to_user(argp + sizeof(struct blk_zone_report), zones,
				 sizeof(struct blk_zone) * rep.nr_zones))
			ret = -EFAULT;
	}

 out:
	kvfree(zones);

	return ret;
}

/*
 * BLKRESETZONE ioctl processing.
 * Called from blkdev_ioctl.
 */
int blkdev_reset_zones_ioctl(struct block_device *bdev, fmode_t mode,
			     unsigned int cmd, unsigned long arg)
{
	void __user *argp = (void __user *)arg;
	struct request_queue *q;
	struct blk_zone_range zrange;

	if (!argp)
		return -EINVAL;

	q = bdev_get_queue(bdev);
	if (!q)
		return -ENXIO;

	if (!blk_queue_is_zoned(q))
		return -ENOTTY;

	if (!capable(CAP_SYS_ADMIN))
		return -EACCES;

	if (!(mode & FMODE_WRITE))
		return -EBADF;

	if (copy_from_user(&zrange, argp, sizeof(struct blk_zone_range)))
		return -EFAULT;

	return blkdev_reset_zones(bdev, zrange.sector, zrange.nr_sectors,
				  GFP_KERNEL);
}

static inline unsigned long *blk_alloc_zone_bitmap(int node,
						   unsigned int nr_zones)
{
	return kcalloc_node(BITS_TO_LONGS(nr_zones), sizeof(unsigned long),
			    GFP_NOIO, node);
}

/*
 * Allocate an array of struct blk_zone to get nr_zones zone information.
 * The allocated array may be smaller than nr_zones.
 */
static struct blk_zone *blk_alloc_zones(unsigned int *nr_zones)
{
	struct blk_zone *zones;
	size_t nrz = min(*nr_zones, BLK_ZONED_REPORT_MAX_ZONES);

	/*
	 * GFP_KERNEL here is meaningless as the caller task context has
	 * the PF_MEMALLOC_NOIO flag set in blk_revalidate_disk_zones()
	 * with memalloc_noio_save().
	 */
	zones = kvcalloc(nrz, sizeof(struct blk_zone), GFP_KERNEL);
	if (!zones) {
		*nr_zones = 0;
		return NULL;
	}

	*nr_zones = nrz;

	return zones;
}

void blk_queue_free_zone_bitmaps(struct request_queue *q)
{
	kfree(q->seq_zones_bitmap);
	q->seq_zones_bitmap = NULL;
	kfree(q->seq_zones_wlock);
	q->seq_zones_wlock = NULL;
}

/**
 * blk_revalidate_disk_zones - (re)allocate and initialize zone bitmaps
 * @disk:	Target disk
 *
 * Helper function for low-level device drivers to (re) allocate and initialize
 * a disk request queue zone bitmaps. This functions should normally be called
 * within the disk ->revalidate method. For BIO based queues, no zone bitmap
 * is allocated.
 */
int blk_revalidate_disk_zones(struct gendisk *disk)
{
	struct request_queue *q = disk->queue;
	unsigned int nr_zones = __blkdev_nr_zones(q, get_capacity(disk));
	unsigned long *seq_zones_wlock = NULL, *seq_zones_bitmap = NULL;
	unsigned int i, rep_nr_zones = 0, z = 0, nrz;
	struct blk_zone *zones = NULL;
	unsigned int noio_flag;
	sector_t sector = 0;
	int ret = 0;

	/*
	 * BIO based queues do not use a scheduler so only q->nr_zones
	 * needs to be updated so that the sysfs exposed value is correct.
	 */
	if (!queue_is_mq(q)) {
		q->nr_zones = nr_zones;
		return 0;
	}

	/*
	 * Ensure that all memory allocations in this context are done as
	 * if GFP_NOIO was specified.
	 */
	noio_flag = memalloc_noio_save();

	if (!blk_queue_is_zoned(q) || !nr_zones) {
		nr_zones = 0;
		goto update;
	}

	/* Allocate bitmaps */
	ret = -ENOMEM;
	seq_zones_wlock = blk_alloc_zone_bitmap(q->node, nr_zones);
	if (!seq_zones_wlock)
		goto out;
	seq_zones_bitmap = blk_alloc_zone_bitmap(q->node, nr_zones);
	if (!seq_zones_bitmap)
		goto out;

	/* Get zone information and initialize seq_zones_bitmap */
	rep_nr_zones = nr_zones;
	zones = blk_alloc_zones(&rep_nr_zones);
	if (!zones)
		goto out;

	while (z < nr_zones) {
		nrz = min(nr_zones - z, rep_nr_zones);
		ret = blk_report_zones(disk, sector, zones, &nrz);
		if (ret)
			goto out;
		if (!nrz)
			break;
		for (i = 0; i < nrz; i++) {
			if (zones[i].type != BLK_ZONE_TYPE_CONVENTIONAL)
				set_bit(z, seq_zones_bitmap);
			z++;
		}
		sector += nrz * blk_queue_zone_sectors(q);
	}

	if (WARN_ON(z != nr_zones)) {
		ret = -EIO;
		goto out;
	}

update:
	/*
	 * Install the new bitmaps, making sure the queue is stopped and
	 * all I/Os are completed (i.e. a scheduler is not referencing the
	 * bitmaps).
	 */
	blk_mq_freeze_queue(q);
	q->nr_zones = nr_zones;
	swap(q->seq_zones_wlock, seq_zones_wlock);
	swap(q->seq_zones_bitmap, seq_zones_bitmap);
	blk_mq_unfreeze_queue(q);

out:
	memalloc_noio_restore(noio_flag);

	kvfree(zones);
	kfree(seq_zones_wlock);
	kfree(seq_zones_bitmap);

	if (ret) {
		pr_warn("%s: failed to revalidate zones\n", disk->disk_name);
		blk_mq_freeze_queue(q);
		blk_queue_free_zone_bitmaps(q);
		blk_mq_unfreeze_queue(q);
	}

	return ret;
}
EXPORT_SYMBOL_GPL(blk_revalidate_disk_zones);