xref: /linux/drivers/scsi/sd_zbc.c (revision a1ff5a7d78a036d6c2178ee5acd6ba4946243800)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * SCSI Zoned Block commands
4  *
5  * Copyright (C) 2014-2015 SUSE Linux GmbH
6  * Written by: Hannes Reinecke <hare@suse.de>
7  * Modified by: Damien Le Moal <damien.lemoal@hgst.com>
8  * Modified by: Shaun Tancheff <shaun.tancheff@seagate.com>
9  */
10 
11 #include <linux/blkdev.h>
12 #include <linux/vmalloc.h>
13 #include <linux/sched/mm.h>
14 #include <linux/mutex.h>
15 
16 #include <asm/unaligned.h>
17 
18 #include <scsi/scsi.h>
19 #include <scsi/scsi_cmnd.h>
20 
21 #include "sd.h"
22 
23 #define CREATE_TRACE_POINTS
24 #include "sd_trace.h"
25 
26 /* Whether or not a SCSI zone descriptor describes a gap zone. */
sd_zbc_is_gap_zone(const u8 buf[64])27 static bool sd_zbc_is_gap_zone(const u8 buf[64])
28 {
29 	return (buf[0] & 0xf) == ZBC_ZONE_TYPE_GAP;
30 }
31 
32 /**
33  * sd_zbc_parse_report - Parse a SCSI zone descriptor
34  * @sdkp: SCSI disk pointer.
35  * @buf: SCSI zone descriptor.
36  * @idx: Index of the zone relative to the first zone reported by the current
37  *	sd_zbc_report_zones() call.
38  * @cb: Callback function pointer.
39  * @data: Second argument passed to @cb.
40  *
41  * Return: Value returned by @cb.
42  *
43  * Convert a SCSI zone descriptor into struct blk_zone format. Additionally,
44  * call @cb(blk_zone, @data).
45  */
sd_zbc_parse_report(struct scsi_disk * sdkp,const u8 buf[64],unsigned int idx,report_zones_cb cb,void * data)46 static int sd_zbc_parse_report(struct scsi_disk *sdkp, const u8 buf[64],
47 			       unsigned int idx, report_zones_cb cb, void *data)
48 {
49 	struct scsi_device *sdp = sdkp->device;
50 	struct blk_zone zone = { 0 };
51 	sector_t start_lba, gran;
52 	int ret;
53 
54 	if (WARN_ON_ONCE(sd_zbc_is_gap_zone(buf)))
55 		return -EINVAL;
56 
57 	zone.type = buf[0] & 0x0f;
58 	zone.cond = (buf[1] >> 4) & 0xf;
59 	if (buf[1] & 0x01)
60 		zone.reset = 1;
61 	if (buf[1] & 0x02)
62 		zone.non_seq = 1;
63 
64 	start_lba = get_unaligned_be64(&buf[16]);
65 	zone.start = logical_to_sectors(sdp, start_lba);
66 	zone.capacity = logical_to_sectors(sdp, get_unaligned_be64(&buf[8]));
67 	zone.len = zone.capacity;
68 	if (sdkp->zone_starting_lba_gran) {
69 		gran = logical_to_sectors(sdp, sdkp->zone_starting_lba_gran);
70 		if (zone.len > gran) {
71 			sd_printk(KERN_ERR, sdkp,
72 				  "Invalid zone at LBA %llu with capacity %llu and length %llu; granularity = %llu\n",
73 				  start_lba,
74 				  sectors_to_logical(sdp, zone.capacity),
75 				  sectors_to_logical(sdp, zone.len),
76 				  sectors_to_logical(sdp, gran));
77 			return -EINVAL;
78 		}
79 		/*
80 		 * Use the starting LBA granularity instead of the zone length
81 		 * obtained from the REPORT ZONES command.
82 		 */
83 		zone.len = gran;
84 	}
85 	if (zone.cond == ZBC_ZONE_COND_FULL)
86 		zone.wp = zone.start + zone.len;
87 	else
88 		zone.wp = logical_to_sectors(sdp, get_unaligned_be64(&buf[24]));
89 
90 	ret = cb(&zone, idx, data);
91 	if (ret)
92 		return ret;
93 
94 	return 0;
95 }
96 
97 /**
98  * sd_zbc_do_report_zones - Issue a REPORT ZONES scsi command.
99  * @sdkp: The target disk
100  * @buf: vmalloc-ed buffer to use for the reply
101  * @buflen: the buffer size
102  * @lba: Start LBA of the report
103  * @partial: Do partial report
104  *
105  * For internal use during device validation.
106  * Using partial=true can significantly speed up execution of a report zones
107  * command because the disk does not have to count all possible report matching
108  * zones and will only report the count of zones fitting in the command reply
109  * buffer.
110  */
sd_zbc_do_report_zones(struct scsi_disk * sdkp,unsigned char * buf,unsigned int buflen,sector_t lba,bool partial)111 static int sd_zbc_do_report_zones(struct scsi_disk *sdkp, unsigned char *buf,
112 				  unsigned int buflen, sector_t lba,
113 				  bool partial)
114 {
115 	struct scsi_device *sdp = sdkp->device;
116 	const int timeout = sdp->request_queue->rq_timeout;
117 	struct scsi_sense_hdr sshdr;
118 	const struct scsi_exec_args exec_args = {
119 		.sshdr = &sshdr,
120 	};
121 	unsigned char cmd[16];
122 	unsigned int rep_len;
123 	int result;
124 
125 	memset(cmd, 0, 16);
126 	cmd[0] = ZBC_IN;
127 	cmd[1] = ZI_REPORT_ZONES;
128 	put_unaligned_be64(lba, &cmd[2]);
129 	put_unaligned_be32(buflen, &cmd[10]);
130 	if (partial)
131 		cmd[14] = ZBC_REPORT_ZONE_PARTIAL;
132 
133 	result = scsi_execute_cmd(sdp, cmd, REQ_OP_DRV_IN, buf, buflen,
134 				  timeout, SD_MAX_RETRIES, &exec_args);
135 	if (result) {
136 		sd_printk(KERN_ERR, sdkp,
137 			  "REPORT ZONES start lba %llu failed\n", lba);
138 		sd_print_result(sdkp, "REPORT ZONES", result);
139 		if (result > 0 && scsi_sense_valid(&sshdr))
140 			sd_print_sense_hdr(sdkp, &sshdr);
141 		return -EIO;
142 	}
143 
144 	rep_len = get_unaligned_be32(&buf[0]);
145 	if (rep_len < 64) {
146 		sd_printk(KERN_ERR, sdkp,
147 			  "REPORT ZONES report invalid length %u\n",
148 			  rep_len);
149 		return -EIO;
150 	}
151 
152 	return 0;
153 }
154 
155 /**
156  * sd_zbc_alloc_report_buffer() - Allocate a buffer for report zones reply.
157  * @sdkp: The target disk
158  * @nr_zones: Maximum number of zones to report
159  * @buflen: Size of the buffer allocated
160  *
161  * Try to allocate a reply buffer for the number of requested zones.
162  * The size of the buffer allocated may be smaller than requested to
163  * satify the device constraint (max_hw_sectors, max_segments, etc).
164  *
165  * Return the address of the allocated buffer and update @buflen with
166  * the size of the allocated buffer.
167  */
sd_zbc_alloc_report_buffer(struct scsi_disk * sdkp,unsigned int nr_zones,size_t * buflen)168 static void *sd_zbc_alloc_report_buffer(struct scsi_disk *sdkp,
169 					unsigned int nr_zones, size_t *buflen)
170 {
171 	struct request_queue *q = sdkp->disk->queue;
172 	size_t bufsize;
173 	void *buf;
174 
175 	/*
176 	 * Report zone buffer size should be at most 64B times the number of
177 	 * zones requested plus the 64B reply header, but should be aligned
178 	 * to SECTOR_SIZE for ATA devices.
179 	 * Make sure that this size does not exceed the hardware capabilities.
180 	 * Furthermore, since the report zone command cannot be split, make
181 	 * sure that the allocated buffer can always be mapped by limiting the
182 	 * number of pages allocated to the HBA max segments limit.
183 	 */
184 	nr_zones = min(nr_zones, sdkp->zone_info.nr_zones);
185 	bufsize = roundup((nr_zones + 1) * 64, SECTOR_SIZE);
186 	bufsize = min_t(size_t, bufsize,
187 			queue_max_hw_sectors(q) << SECTOR_SHIFT);
188 	bufsize = min_t(size_t, bufsize, queue_max_segments(q) << PAGE_SHIFT);
189 
190 	while (bufsize >= SECTOR_SIZE) {
191 		buf = __vmalloc(bufsize,
192 				GFP_KERNEL | __GFP_ZERO | __GFP_NORETRY);
193 		if (buf) {
194 			*buflen = bufsize;
195 			return buf;
196 		}
197 		bufsize = rounddown(bufsize >> 1, SECTOR_SIZE);
198 	}
199 
200 	return NULL;
201 }
202 
203 /**
204  * sd_zbc_zone_sectors - Get the device zone size in number of 512B sectors.
205  * @sdkp: The target disk
206  */
sd_zbc_zone_sectors(struct scsi_disk * sdkp)207 static inline sector_t sd_zbc_zone_sectors(struct scsi_disk *sdkp)
208 {
209 	return logical_to_sectors(sdkp->device, sdkp->zone_info.zone_blocks);
210 }
211 
212 /**
213  * sd_zbc_report_zones - SCSI .report_zones() callback.
214  * @disk: Disk to report zones for.
215  * @sector: Start sector.
216  * @nr_zones: Maximum number of zones to report.
217  * @cb: Callback function called to report zone information.
218  * @data: Second argument passed to @cb.
219  *
220  * Called by the block layer to iterate over zone information. See also the
221  * disk->fops->report_zones() calls in block/blk-zoned.c.
222  */
sd_zbc_report_zones(struct gendisk * disk,sector_t sector,unsigned int nr_zones,report_zones_cb cb,void * data)223 int sd_zbc_report_zones(struct gendisk *disk, sector_t sector,
224 			unsigned int nr_zones, report_zones_cb cb, void *data)
225 {
226 	struct scsi_disk *sdkp = scsi_disk(disk);
227 	sector_t lba = sectors_to_logical(sdkp->device, sector);
228 	unsigned int nr, i;
229 	unsigned char *buf;
230 	u64 zone_length, start_lba;
231 	size_t offset, buflen = 0;
232 	int zone_idx = 0;
233 	int ret;
234 
235 	if (sdkp->device->type != TYPE_ZBC)
236 		/* Not a zoned device */
237 		return -EOPNOTSUPP;
238 
239 	if (!sdkp->capacity)
240 		/* Device gone or invalid */
241 		return -ENODEV;
242 
243 	buf = sd_zbc_alloc_report_buffer(sdkp, nr_zones, &buflen);
244 	if (!buf)
245 		return -ENOMEM;
246 
247 	while (zone_idx < nr_zones && lba < sdkp->capacity) {
248 		ret = sd_zbc_do_report_zones(sdkp, buf, buflen, lba, true);
249 		if (ret)
250 			goto out;
251 
252 		offset = 0;
253 		nr = min(nr_zones, get_unaligned_be32(&buf[0]) / 64);
254 		if (!nr)
255 			break;
256 
257 		for (i = 0; i < nr && zone_idx < nr_zones; i++) {
258 			offset += 64;
259 			start_lba = get_unaligned_be64(&buf[offset + 16]);
260 			zone_length = get_unaligned_be64(&buf[offset + 8]);
261 			if ((zone_idx == 0 &&
262 			    (lba < start_lba ||
263 			     lba >= start_lba + zone_length)) ||
264 			    (zone_idx > 0 && start_lba != lba) ||
265 			    start_lba + zone_length < start_lba) {
266 				sd_printk(KERN_ERR, sdkp,
267 					  "Zone %d at LBA %llu is invalid: %llu + %llu\n",
268 					  zone_idx, lba, start_lba, zone_length);
269 				ret = -EINVAL;
270 				goto out;
271 			}
272 			lba = start_lba + zone_length;
273 			if (sd_zbc_is_gap_zone(&buf[offset])) {
274 				if (sdkp->zone_starting_lba_gran)
275 					continue;
276 				sd_printk(KERN_ERR, sdkp,
277 					  "Gap zone without constant LBA offsets\n");
278 				ret = -EINVAL;
279 				goto out;
280 			}
281 
282 			ret = sd_zbc_parse_report(sdkp, buf + offset, zone_idx,
283 						  cb, data);
284 			if (ret)
285 				goto out;
286 
287 			zone_idx++;
288 		}
289 	}
290 
291 	ret = zone_idx;
292 out:
293 	kvfree(buf);
294 	return ret;
295 }
296 
sd_zbc_cmnd_checks(struct scsi_cmnd * cmd)297 static blk_status_t sd_zbc_cmnd_checks(struct scsi_cmnd *cmd)
298 {
299 	struct request *rq = scsi_cmd_to_rq(cmd);
300 	struct scsi_disk *sdkp = scsi_disk(rq->q->disk);
301 	sector_t sector = blk_rq_pos(rq);
302 
303 	if (sdkp->device->type != TYPE_ZBC)
304 		/* Not a zoned device */
305 		return BLK_STS_IOERR;
306 
307 	if (sdkp->device->changed)
308 		return BLK_STS_IOERR;
309 
310 	if (sector & (sd_zbc_zone_sectors(sdkp) - 1))
311 		/* Unaligned request */
312 		return BLK_STS_IOERR;
313 
314 	return BLK_STS_OK;
315 }
316 
317 /**
318  * sd_zbc_setup_zone_mgmt_cmnd - Prepare a zone ZBC_OUT command. The operations
319  *			can be RESET WRITE POINTER, OPEN, CLOSE or FINISH.
320  * @cmd: the command to setup
321  * @op: Operation to be performed
322  * @all: All zones control
323  *
324  * Called from sd_init_command() for REQ_OP_ZONE_RESET, REQ_OP_ZONE_RESET_ALL,
325  * REQ_OP_ZONE_OPEN, REQ_OP_ZONE_CLOSE or REQ_OP_ZONE_FINISH requests.
326  */
sd_zbc_setup_zone_mgmt_cmnd(struct scsi_cmnd * cmd,unsigned char op,bool all)327 blk_status_t sd_zbc_setup_zone_mgmt_cmnd(struct scsi_cmnd *cmd,
328 					 unsigned char op, bool all)
329 {
330 	struct request *rq = scsi_cmd_to_rq(cmd);
331 	sector_t sector = blk_rq_pos(rq);
332 	struct scsi_disk *sdkp = scsi_disk(rq->q->disk);
333 	sector_t block = sectors_to_logical(sdkp->device, sector);
334 	blk_status_t ret;
335 
336 	ret = sd_zbc_cmnd_checks(cmd);
337 	if (ret != BLK_STS_OK)
338 		return ret;
339 
340 	cmd->cmd_len = 16;
341 	memset(cmd->cmnd, 0, cmd->cmd_len);
342 	cmd->cmnd[0] = ZBC_OUT;
343 	cmd->cmnd[1] = op;
344 	if (all)
345 		cmd->cmnd[14] = 0x1;
346 	else
347 		put_unaligned_be64(block, &cmd->cmnd[2]);
348 
349 	rq->timeout = SD_TIMEOUT;
350 	cmd->sc_data_direction = DMA_NONE;
351 	cmd->transfersize = 0;
352 	cmd->allowed = 0;
353 
354 	return BLK_STS_OK;
355 }
356 
357 /**
358  * sd_zbc_complete - ZBC command post processing.
359  * @cmd: Completed command
360  * @good_bytes: Command reply bytes
361  * @sshdr: command sense header
362  *
363  * Called from sd_done() to handle zone commands errors and updates to the
364  * device queue zone write pointer offset cahce.
365  */
sd_zbc_complete(struct scsi_cmnd * cmd,unsigned int good_bytes,struct scsi_sense_hdr * sshdr)366 unsigned int sd_zbc_complete(struct scsi_cmnd *cmd, unsigned int good_bytes,
367 		     struct scsi_sense_hdr *sshdr)
368 {
369 	int result = cmd->result;
370 	struct request *rq = scsi_cmd_to_rq(cmd);
371 
372 	if (op_is_zone_mgmt(req_op(rq)) &&
373 	    result &&
374 	    sshdr->sense_key == ILLEGAL_REQUEST &&
375 	    sshdr->asc == 0x24) {
376 		/*
377 		 * INVALID FIELD IN CDB error: a zone management command was
378 		 * attempted on a conventional zone. Nothing to worry about,
379 		 * so be quiet about the error.
380 		 */
381 		rq->rq_flags |= RQF_QUIET;
382 	}
383 
384 	return good_bytes;
385 }
386 
387 /**
388  * sd_zbc_check_zoned_characteristics - Check zoned block device characteristics
389  * @sdkp: Target disk
390  * @buf: Buffer where to store the VPD page data
391  *
392  * Read VPD page B6, get information and check that reads are unconstrained.
393  */
sd_zbc_check_zoned_characteristics(struct scsi_disk * sdkp,unsigned char * buf)394 static int sd_zbc_check_zoned_characteristics(struct scsi_disk *sdkp,
395 					      unsigned char *buf)
396 {
397 	u64 zone_starting_lba_gran;
398 
399 	if (scsi_get_vpd_page(sdkp->device, 0xb6, buf, 64)) {
400 		sd_printk(KERN_NOTICE, sdkp,
401 			  "Read zoned characteristics VPD page failed\n");
402 		return -ENODEV;
403 	}
404 
405 	if (sdkp->device->type != TYPE_ZBC) {
406 		/* Host-aware */
407 		sdkp->urswrz = 1;
408 		sdkp->zones_optimal_open = get_unaligned_be32(&buf[8]);
409 		sdkp->zones_optimal_nonseq = get_unaligned_be32(&buf[12]);
410 		sdkp->zones_max_open = 0;
411 		return 0;
412 	}
413 
414 	/* Host-managed */
415 	sdkp->urswrz = buf[4] & 1;
416 	sdkp->zones_optimal_open = 0;
417 	sdkp->zones_optimal_nonseq = 0;
418 	sdkp->zones_max_open = get_unaligned_be32(&buf[16]);
419 	/* Check zone alignment method */
420 	switch (buf[23] & 0xf) {
421 	case 0:
422 	case ZBC_CONSTANT_ZONE_LENGTH:
423 		/* Use zone length */
424 		break;
425 	case ZBC_CONSTANT_ZONE_START_OFFSET:
426 		zone_starting_lba_gran = get_unaligned_be64(&buf[24]);
427 		if (zone_starting_lba_gran == 0 ||
428 		    !is_power_of_2(zone_starting_lba_gran) ||
429 		    logical_to_sectors(sdkp->device, zone_starting_lba_gran) >
430 		    UINT_MAX) {
431 			sd_printk(KERN_ERR, sdkp,
432 				  "Invalid zone starting LBA granularity %llu\n",
433 				  zone_starting_lba_gran);
434 			return -ENODEV;
435 		}
436 		sdkp->zone_starting_lba_gran = zone_starting_lba_gran;
437 		break;
438 	default:
439 		sd_printk(KERN_ERR, sdkp, "Invalid zone alignment method\n");
440 		return -ENODEV;
441 	}
442 
443 	/*
444 	 * Check for unconstrained reads: host-managed devices with
445 	 * constrained reads (drives failing read after write pointer)
446 	 * are not supported.
447 	 */
448 	if (!sdkp->urswrz) {
449 		if (sdkp->first_scan)
450 			sd_printk(KERN_NOTICE, sdkp,
451 			  "constrained reads devices are not supported\n");
452 		return -ENODEV;
453 	}
454 
455 	return 0;
456 }
457 
458 /**
459  * sd_zbc_check_capacity - Check the device capacity
460  * @sdkp: Target disk
461  * @buf: command buffer
462  * @zblocks: zone size in logical blocks
463  *
464  * Get the device zone size and check that the device capacity as reported
465  * by READ CAPACITY matches the max_lba value (plus one) of the report zones
466  * command reply for devices with RC_BASIS == 0.
467  *
468  * Returns 0 upon success or an error code upon failure.
469  */
sd_zbc_check_capacity(struct scsi_disk * sdkp,unsigned char * buf,u32 * zblocks)470 static int sd_zbc_check_capacity(struct scsi_disk *sdkp, unsigned char *buf,
471 				 u32 *zblocks)
472 {
473 	u64 zone_blocks;
474 	sector_t max_lba;
475 	unsigned char *rec;
476 	int ret;
477 
478 	/* Do a report zone to get max_lba and the size of the first zone */
479 	ret = sd_zbc_do_report_zones(sdkp, buf, SD_BUF_SIZE, 0, false);
480 	if (ret)
481 		return ret;
482 
483 	if (sdkp->rc_basis == 0) {
484 		/* The max_lba field is the capacity of this device */
485 		max_lba = get_unaligned_be64(&buf[8]);
486 		if (sdkp->capacity != max_lba + 1) {
487 			if (sdkp->first_scan)
488 				sd_printk(KERN_WARNING, sdkp,
489 					"Changing capacity from %llu to max LBA+1 %llu\n",
490 					(unsigned long long)sdkp->capacity,
491 					(unsigned long long)max_lba + 1);
492 			sdkp->capacity = max_lba + 1;
493 		}
494 	}
495 
496 	if (sdkp->zone_starting_lba_gran == 0) {
497 		/* Get the size of the first reported zone */
498 		rec = buf + 64;
499 		zone_blocks = get_unaligned_be64(&rec[8]);
500 		if (logical_to_sectors(sdkp->device, zone_blocks) > UINT_MAX) {
501 			if (sdkp->first_scan)
502 				sd_printk(KERN_NOTICE, sdkp,
503 					  "Zone size too large\n");
504 			return -EFBIG;
505 		}
506 	} else {
507 		zone_blocks = sdkp->zone_starting_lba_gran;
508 	}
509 
510 	if (!is_power_of_2(zone_blocks)) {
511 		sd_printk(KERN_ERR, sdkp,
512 			  "Zone size %llu is not a power of two.\n",
513 			  zone_blocks);
514 		return -EINVAL;
515 	}
516 
517 	*zblocks = zone_blocks;
518 
519 	return 0;
520 }
521 
sd_zbc_print_zones(struct scsi_disk * sdkp)522 static void sd_zbc_print_zones(struct scsi_disk *sdkp)
523 {
524 	if (sdkp->device->type != TYPE_ZBC || !sdkp->capacity)
525 		return;
526 
527 	if (sdkp->capacity & (sdkp->zone_info.zone_blocks - 1))
528 		sd_printk(KERN_NOTICE, sdkp,
529 			  "%u zones of %u logical blocks + 1 runt zone\n",
530 			  sdkp->zone_info.nr_zones - 1,
531 			  sdkp->zone_info.zone_blocks);
532 	else
533 		sd_printk(KERN_NOTICE, sdkp,
534 			  "%u zones of %u logical blocks\n",
535 			  sdkp->zone_info.nr_zones,
536 			  sdkp->zone_info.zone_blocks);
537 }
538 
539 /*
540  * Call blk_revalidate_disk_zones() if any of the zoned disk properties have
541  * changed that make it necessary to call that function. Called by
542  * sd_revalidate_disk() after the gendisk capacity has been set.
543  */
sd_zbc_revalidate_zones(struct scsi_disk * sdkp)544 int sd_zbc_revalidate_zones(struct scsi_disk *sdkp)
545 {
546 	struct gendisk *disk = sdkp->disk;
547 	struct request_queue *q = disk->queue;
548 	u32 zone_blocks = sdkp->early_zone_info.zone_blocks;
549 	unsigned int nr_zones = sdkp->early_zone_info.nr_zones;
550 	unsigned int flags;
551 	int ret;
552 
553 	/*
554 	 * There is nothing to do for regular disks, including host-aware disks
555 	 * that have partitions.
556 	 */
557 	if (!blk_queue_is_zoned(q))
558 		return 0;
559 
560 	if (sdkp->zone_info.zone_blocks == zone_blocks &&
561 	    sdkp->zone_info.nr_zones == nr_zones &&
562 	    disk->nr_zones == nr_zones)
563 		return 0;
564 
565 	sdkp->zone_info.zone_blocks = zone_blocks;
566 	sdkp->zone_info.nr_zones = nr_zones;
567 
568 	flags = memalloc_noio_save();
569 	ret = blk_revalidate_disk_zones(disk);
570 	memalloc_noio_restore(flags);
571 	if (ret) {
572 		sdkp->zone_info = (struct zoned_disk_info){ };
573 		sdkp->capacity = 0;
574 		return ret;
575 	}
576 
577 	sd_zbc_print_zones(sdkp);
578 
579 	return 0;
580 }
581 
582 /**
583  * sd_zbc_read_zones - Read zone information and update the request queue
584  * @sdkp: SCSI disk pointer.
585  * @lim: queue limits to read into
586  * @buf: 512 byte buffer used for storing SCSI command output.
587  *
588  * Read zone information and update the request queue zone characteristics and
589  * also the zoned device information in *sdkp. Called by sd_revalidate_disk()
590  * before the gendisk capacity has been set.
591  */
sd_zbc_read_zones(struct scsi_disk * sdkp,struct queue_limits * lim,u8 buf[SD_BUF_SIZE])592 int sd_zbc_read_zones(struct scsi_disk *sdkp, struct queue_limits *lim,
593 		u8 buf[SD_BUF_SIZE])
594 {
595 	unsigned int nr_zones;
596 	u32 zone_blocks = 0;
597 	int ret;
598 
599 	if (sdkp->device->type != TYPE_ZBC)
600 		return 0;
601 
602 	lim->features |= BLK_FEAT_ZONED;
603 
604 	/*
605 	 * Per ZBC and ZAC specifications, writes in sequential write required
606 	 * zones of host-managed devices must be aligned to the device physical
607 	 * block size.
608 	 */
609 	lim->zone_write_granularity = sdkp->physical_block_size;
610 
611 	/* READ16/WRITE16/SYNC16 is mandatory for ZBC devices */
612 	sdkp->device->use_16_for_rw = 1;
613 	sdkp->device->use_10_for_rw = 0;
614 	sdkp->device->use_16_for_sync = 1;
615 
616 	/* Check zoned block device characteristics (unconstrained reads) */
617 	ret = sd_zbc_check_zoned_characteristics(sdkp, buf);
618 	if (ret)
619 		goto err;
620 
621 	/* Check the device capacity reported by report zones */
622 	ret = sd_zbc_check_capacity(sdkp, buf, &zone_blocks);
623 	if (ret != 0)
624 		goto err;
625 
626 	nr_zones = round_up(sdkp->capacity, zone_blocks) >> ilog2(zone_blocks);
627 	sdkp->early_zone_info.nr_zones = nr_zones;
628 	sdkp->early_zone_info.zone_blocks = zone_blocks;
629 
630 	/* The drive satisfies the kernel restrictions: set it up */
631 	if (sdkp->zones_max_open == U32_MAX)
632 		lim->max_open_zones = 0;
633 	else
634 		lim->max_open_zones = sdkp->zones_max_open;
635 	lim->max_active_zones = 0;
636 	lim->chunk_sectors = logical_to_sectors(sdkp->device, zone_blocks);
637 	/* Enable block layer zone append emulation */
638 	lim->max_zone_append_sectors = 0;
639 
640 	return 0;
641 
642 err:
643 	sdkp->capacity = 0;
644 
645 	return ret;
646 }
647