1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/vmalloc.h>
3 #include <linux/bitmap.h>
6 #define CREATE_TRACE_POINTS
7 #include "null_blk_trace.h"
9 #define MB_TO_SECTS(mb) (((sector_t)mb * SZ_1M) >> SECTOR_SHIFT)
11 static inline unsigned int null_zone_no(struct nullb_device *dev, sector_t sect)
13 return sect >> ilog2(dev->zone_size_sects);
16 int null_init_zoned_dev(struct nullb_device *dev, struct request_queue *q)
18 sector_t dev_capacity_sects, zone_capacity_sects;
22 if (!is_power_of_2(dev->zone_size)) {
23 pr_err("zone_size must be power-of-two\n");
26 if (dev->zone_size > dev->size) {
27 pr_err("Zone size larger than device capacity\n");
31 if (!dev->zone_capacity)
32 dev->zone_capacity = dev->zone_size;
34 if (dev->zone_capacity > dev->zone_size) {
35 pr_err("null_blk: zone capacity (%lu MB) larger than zone size (%lu MB)\n",
36 dev->zone_capacity, dev->zone_size);
40 zone_capacity_sects = MB_TO_SECTS(dev->zone_capacity);
41 dev_capacity_sects = MB_TO_SECTS(dev->size);
42 dev->zone_size_sects = MB_TO_SECTS(dev->zone_size);
43 dev->nr_zones = dev_capacity_sects >> ilog2(dev->zone_size_sects);
44 if (dev_capacity_sects & (dev->zone_size_sects - 1))
47 dev->zones = kvmalloc_array(dev->nr_zones, sizeof(struct blk_zone),
48 GFP_KERNEL | __GFP_ZERO);
53 * With memory backing, the zone_lock spinlock needs to be temporarily
54 * released to avoid scheduling in atomic context. To guarantee zone
55 * information protection, use a bitmap to lock zones with
56 * wait_on_bit_lock_io(). Sleeping on the lock is OK as memory backing
57 * implies that the queue is marked with BLK_MQ_F_BLOCKING.
59 spin_lock_init(&dev->zone_lock);
60 if (dev->memory_backed) {
61 dev->zone_locks = bitmap_zalloc(dev->nr_zones, GFP_KERNEL);
62 if (!dev->zone_locks) {
68 if (dev->zone_nr_conv >= dev->nr_zones) {
69 dev->zone_nr_conv = dev->nr_zones - 1;
70 pr_info("changed the number of conventional zones to %u",
74 /* Max active zones has to be < nbr of seq zones in order to be enforceable */
75 if (dev->zone_max_active >= dev->nr_zones - dev->zone_nr_conv) {
76 dev->zone_max_active = 0;
77 pr_info("zone_max_active limit disabled, limit >= zone count\n");
80 /* Max open zones has to be <= max active zones */
81 if (dev->zone_max_active && dev->zone_max_open > dev->zone_max_active) {
82 dev->zone_max_open = dev->zone_max_active;
83 pr_info("changed the maximum number of open zones to %u\n",
85 } else if (dev->zone_max_open >= dev->nr_zones - dev->zone_nr_conv) {
86 dev->zone_max_open = 0;
87 pr_info("zone_max_open limit disabled, limit >= zone count\n");
90 for (i = 0; i < dev->zone_nr_conv; i++) {
91 struct blk_zone *zone = &dev->zones[i];
94 zone->len = dev->zone_size_sects;
95 zone->capacity = zone->len;
96 zone->wp = zone->start + zone->len;
97 zone->type = BLK_ZONE_TYPE_CONVENTIONAL;
98 zone->cond = BLK_ZONE_COND_NOT_WP;
100 sector += dev->zone_size_sects;
103 for (i = dev->zone_nr_conv; i < dev->nr_zones; i++) {
104 struct blk_zone *zone = &dev->zones[i];
106 zone->start = zone->wp = sector;
107 if (zone->start + dev->zone_size_sects > dev_capacity_sects)
108 zone->len = dev_capacity_sects - zone->start;
110 zone->len = dev->zone_size_sects;
112 min_t(sector_t, zone->len, zone_capacity_sects);
113 zone->type = BLK_ZONE_TYPE_SEQWRITE_REQ;
114 zone->cond = BLK_ZONE_COND_EMPTY;
116 sector += dev->zone_size_sects;
119 q->limits.zoned = BLK_ZONED_HM;
120 blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, q);
121 blk_queue_required_elevator_features(q, ELEVATOR_F_ZBD_SEQ_WRITE);
126 int null_register_zoned_dev(struct nullb *nullb)
128 struct nullb_device *dev = nullb->dev;
129 struct request_queue *q = nullb->q;
131 if (queue_is_mq(q)) {
132 int ret = blk_revalidate_disk_zones(nullb->disk, NULL);
137 blk_queue_chunk_sectors(q, dev->zone_size_sects);
138 q->nr_zones = blkdev_nr_zones(nullb->disk);
141 blk_queue_max_zone_append_sectors(q, dev->zone_size_sects);
142 blk_queue_max_open_zones(q, dev->zone_max_open);
143 blk_queue_max_active_zones(q, dev->zone_max_active);
148 void null_free_zoned_dev(struct nullb_device *dev)
150 bitmap_free(dev->zone_locks);
155 static inline void null_lock_zone(struct nullb_device *dev, unsigned int zno)
157 if (dev->memory_backed)
158 wait_on_bit_lock_io(dev->zone_locks, zno, TASK_UNINTERRUPTIBLE);
159 spin_lock_irq(&dev->zone_lock);
162 static inline void null_unlock_zone(struct nullb_device *dev, unsigned int zno)
164 spin_unlock_irq(&dev->zone_lock);
166 if (dev->memory_backed)
167 clear_and_wake_up_bit(zno, dev->zone_locks);
170 int null_report_zones(struct gendisk *disk, sector_t sector,
171 unsigned int nr_zones, report_zones_cb cb, void *data)
173 struct nullb *nullb = disk->private_data;
174 struct nullb_device *dev = nullb->dev;
175 unsigned int first_zone, i, zno;
176 struct blk_zone zone;
179 first_zone = null_zone_no(dev, sector);
180 if (first_zone >= dev->nr_zones)
183 nr_zones = min(nr_zones, dev->nr_zones - first_zone);
184 trace_nullb_report_zones(nullb, nr_zones);
187 for (i = 0; i < nr_zones; i++, zno++) {
189 * Stacked DM target drivers will remap the zone information by
190 * modifying the zone information passed to the report callback.
191 * So use a local copy to avoid corruption of the device zone
194 null_lock_zone(dev, zno);
195 memcpy(&zone, &dev->zones[zno], sizeof(struct blk_zone));
196 null_unlock_zone(dev, zno);
198 error = cb(&zone, i, data);
207 * This is called in the case of memory backing from null_process_cmd()
208 * with the target zone already locked.
210 size_t null_zone_valid_read_len(struct nullb *nullb,
211 sector_t sector, unsigned int len)
213 struct nullb_device *dev = nullb->dev;
214 struct blk_zone *zone = &dev->zones[null_zone_no(dev, sector)];
215 unsigned int nr_sectors = len >> SECTOR_SHIFT;
217 /* Read must be below the write pointer position */
218 if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL ||
219 sector + nr_sectors <= zone->wp)
222 if (sector > zone->wp)
225 return (zone->wp - sector) << SECTOR_SHIFT;
228 static blk_status_t null_close_zone(struct nullb_device *dev, struct blk_zone *zone)
230 if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
231 return BLK_STS_IOERR;
233 switch (zone->cond) {
234 case BLK_ZONE_COND_CLOSED:
235 /* close operation on closed is not an error */
237 case BLK_ZONE_COND_IMP_OPEN:
238 dev->nr_zones_imp_open--;
240 case BLK_ZONE_COND_EXP_OPEN:
241 dev->nr_zones_exp_open--;
243 case BLK_ZONE_COND_EMPTY:
244 case BLK_ZONE_COND_FULL:
246 return BLK_STS_IOERR;
249 if (zone->wp == zone->start) {
250 zone->cond = BLK_ZONE_COND_EMPTY;
252 zone->cond = BLK_ZONE_COND_CLOSED;
253 dev->nr_zones_closed++;
259 static void null_close_first_imp_zone(struct nullb_device *dev)
263 for (i = dev->zone_nr_conv; i < dev->nr_zones; i++) {
264 if (dev->zones[i].cond == BLK_ZONE_COND_IMP_OPEN) {
265 null_close_zone(dev, &dev->zones[i]);
271 static blk_status_t null_check_active(struct nullb_device *dev)
273 if (!dev->zone_max_active)
276 if (dev->nr_zones_exp_open + dev->nr_zones_imp_open +
277 dev->nr_zones_closed < dev->zone_max_active)
280 return BLK_STS_ZONE_ACTIVE_RESOURCE;
283 static blk_status_t null_check_open(struct nullb_device *dev)
285 if (!dev->zone_max_open)
288 if (dev->nr_zones_exp_open + dev->nr_zones_imp_open < dev->zone_max_open)
291 if (dev->nr_zones_imp_open) {
292 if (null_check_active(dev) == BLK_STS_OK) {
293 null_close_first_imp_zone(dev);
298 return BLK_STS_ZONE_OPEN_RESOURCE;
302 * This function matches the manage open zone resources function in the ZBC standard,
303 * with the addition of max active zones support (added in the ZNS standard).
305 * The function determines if a zone can transition to implicit open or explicit open,
306 * while maintaining the max open zone (and max active zone) limit(s). It may close an
307 * implicit open zone in order to make additional zone resources available.
309 * ZBC states that an implicit open zone shall be closed only if there is not
310 * room within the open limit. However, with the addition of an active limit,
311 * it is not certain that closing an implicit open zone will allow a new zone
312 * to be opened, since we might already be at the active limit capacity.
314 static blk_status_t null_check_zone_resources(struct nullb_device *dev, struct blk_zone *zone)
318 switch (zone->cond) {
319 case BLK_ZONE_COND_EMPTY:
320 ret = null_check_active(dev);
321 if (ret != BLK_STS_OK)
324 case BLK_ZONE_COND_CLOSED:
325 return null_check_open(dev);
327 /* Should never be called for other states */
329 return BLK_STS_IOERR;
333 static blk_status_t null_zone_write(struct nullb_cmd *cmd, sector_t sector,
334 unsigned int nr_sectors, bool append)
336 struct nullb_device *dev = cmd->nq->dev;
337 unsigned int zno = null_zone_no(dev, sector);
338 struct blk_zone *zone = &dev->zones[zno];
341 trace_nullb_zone_op(cmd, zno, zone->cond);
343 if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL) {
345 return BLK_STS_IOERR;
346 return null_process_cmd(cmd, REQ_OP_WRITE, sector, nr_sectors);
349 null_lock_zone(dev, zno);
351 switch (zone->cond) {
352 case BLK_ZONE_COND_FULL:
353 /* Cannot write to a full zone */
356 case BLK_ZONE_COND_EMPTY:
357 case BLK_ZONE_COND_CLOSED:
358 ret = null_check_zone_resources(dev, zone);
359 if (ret != BLK_STS_OK)
362 case BLK_ZONE_COND_IMP_OPEN:
363 case BLK_ZONE_COND_EXP_OPEN:
366 /* Invalid zone condition */
372 * Regular writes must be at the write pointer position.
373 * Zone append writes are automatically issued at the write
374 * pointer and the position returned using the request or BIO
380 cmd->bio->bi_iter.bi_sector = sector;
382 cmd->rq->__sector = sector;
383 } else if (sector != zone->wp) {
388 if (zone->wp + nr_sectors > zone->start + zone->capacity) {
393 if (zone->cond == BLK_ZONE_COND_CLOSED) {
394 dev->nr_zones_closed--;
395 dev->nr_zones_imp_open++;
396 } else if (zone->cond == BLK_ZONE_COND_EMPTY) {
397 dev->nr_zones_imp_open++;
399 if (zone->cond != BLK_ZONE_COND_EXP_OPEN)
400 zone->cond = BLK_ZONE_COND_IMP_OPEN;
403 * Memory backing allocation may sleep: release the zone_lock spinlock
404 * to avoid scheduling in atomic context. Zone operation atomicity is
405 * still guaranteed through the zone_locks bitmap.
407 if (dev->memory_backed)
408 spin_unlock_irq(&dev->zone_lock);
409 ret = null_process_cmd(cmd, REQ_OP_WRITE, sector, nr_sectors);
410 if (dev->memory_backed)
411 spin_lock_irq(&dev->zone_lock);
413 if (ret != BLK_STS_OK)
416 zone->wp += nr_sectors;
417 if (zone->wp == zone->start + zone->capacity) {
418 if (zone->cond == BLK_ZONE_COND_EXP_OPEN)
419 dev->nr_zones_exp_open--;
420 else if (zone->cond == BLK_ZONE_COND_IMP_OPEN)
421 dev->nr_zones_imp_open--;
422 zone->cond = BLK_ZONE_COND_FULL;
427 null_unlock_zone(dev, zno);
432 static blk_status_t null_open_zone(struct nullb_device *dev, struct blk_zone *zone)
436 if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
437 return BLK_STS_IOERR;
439 switch (zone->cond) {
440 case BLK_ZONE_COND_EXP_OPEN:
441 /* open operation on exp open is not an error */
443 case BLK_ZONE_COND_EMPTY:
444 ret = null_check_zone_resources(dev, zone);
445 if (ret != BLK_STS_OK)
448 case BLK_ZONE_COND_IMP_OPEN:
449 dev->nr_zones_imp_open--;
451 case BLK_ZONE_COND_CLOSED:
452 ret = null_check_zone_resources(dev, zone);
453 if (ret != BLK_STS_OK)
455 dev->nr_zones_closed--;
457 case BLK_ZONE_COND_FULL:
459 return BLK_STS_IOERR;
462 zone->cond = BLK_ZONE_COND_EXP_OPEN;
463 dev->nr_zones_exp_open++;
468 static blk_status_t null_finish_zone(struct nullb_device *dev, struct blk_zone *zone)
472 if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
473 return BLK_STS_IOERR;
475 switch (zone->cond) {
476 case BLK_ZONE_COND_FULL:
477 /* finish operation on full is not an error */
479 case BLK_ZONE_COND_EMPTY:
480 ret = null_check_zone_resources(dev, zone);
481 if (ret != BLK_STS_OK)
484 case BLK_ZONE_COND_IMP_OPEN:
485 dev->nr_zones_imp_open--;
487 case BLK_ZONE_COND_EXP_OPEN:
488 dev->nr_zones_exp_open--;
490 case BLK_ZONE_COND_CLOSED:
491 ret = null_check_zone_resources(dev, zone);
492 if (ret != BLK_STS_OK)
494 dev->nr_zones_closed--;
497 return BLK_STS_IOERR;
500 zone->cond = BLK_ZONE_COND_FULL;
501 zone->wp = zone->start + zone->len;
506 static blk_status_t null_reset_zone(struct nullb_device *dev, struct blk_zone *zone)
508 if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
509 return BLK_STS_IOERR;
511 switch (zone->cond) {
512 case BLK_ZONE_COND_EMPTY:
513 /* reset operation on empty is not an error */
515 case BLK_ZONE_COND_IMP_OPEN:
516 dev->nr_zones_imp_open--;
518 case BLK_ZONE_COND_EXP_OPEN:
519 dev->nr_zones_exp_open--;
521 case BLK_ZONE_COND_CLOSED:
522 dev->nr_zones_closed--;
524 case BLK_ZONE_COND_FULL:
527 return BLK_STS_IOERR;
530 zone->cond = BLK_ZONE_COND_EMPTY;
531 zone->wp = zone->start;
536 static blk_status_t null_zone_mgmt(struct nullb_cmd *cmd, enum req_opf op,
539 struct nullb_device *dev = cmd->nq->dev;
540 unsigned int zone_no;
541 struct blk_zone *zone;
545 if (op == REQ_OP_ZONE_RESET_ALL) {
546 for (i = dev->zone_nr_conv; i < dev->nr_zones; i++) {
547 null_lock_zone(dev, i);
548 zone = &dev->zones[i];
549 if (zone->cond != BLK_ZONE_COND_EMPTY) {
550 null_reset_zone(dev, zone);
551 trace_nullb_zone_op(cmd, i, zone->cond);
553 null_unlock_zone(dev, i);
558 zone_no = null_zone_no(dev, sector);
559 zone = &dev->zones[zone_no];
561 null_lock_zone(dev, zone_no);
564 case REQ_OP_ZONE_RESET:
565 ret = null_reset_zone(dev, zone);
567 case REQ_OP_ZONE_OPEN:
568 ret = null_open_zone(dev, zone);
570 case REQ_OP_ZONE_CLOSE:
571 ret = null_close_zone(dev, zone);
573 case REQ_OP_ZONE_FINISH:
574 ret = null_finish_zone(dev, zone);
577 ret = BLK_STS_NOTSUPP;
581 if (ret == BLK_STS_OK)
582 trace_nullb_zone_op(cmd, zone_no, zone->cond);
584 null_unlock_zone(dev, zone_no);
589 blk_status_t null_process_zoned_cmd(struct nullb_cmd *cmd, enum req_opf op,
590 sector_t sector, sector_t nr_sectors)
592 struct nullb_device *dev = cmd->nq->dev;
593 unsigned int zno = null_zone_no(dev, sector);
598 sts = null_zone_write(cmd, sector, nr_sectors, false);
600 case REQ_OP_ZONE_APPEND:
601 sts = null_zone_write(cmd, sector, nr_sectors, true);
603 case REQ_OP_ZONE_RESET:
604 case REQ_OP_ZONE_RESET_ALL:
605 case REQ_OP_ZONE_OPEN:
606 case REQ_OP_ZONE_CLOSE:
607 case REQ_OP_ZONE_FINISH:
608 sts = null_zone_mgmt(cmd, op, sector);
611 null_lock_zone(dev, zno);
612 sts = null_process_cmd(cmd, op, sector, nr_sectors);
613 null_unlock_zone(dev, zno);