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
 23#define ZONE_COND_NAME(name) [BLK_ZONE_COND_##name] = #name
 24static const char *const zone_cond_name[] = {
 25	ZONE_COND_NAME(NOT_WP),
 26	ZONE_COND_NAME(EMPTY),
 27	ZONE_COND_NAME(IMP_OPEN),
 28	ZONE_COND_NAME(EXP_OPEN),
 29	ZONE_COND_NAME(CLOSED),
 30	ZONE_COND_NAME(READONLY),
 31	ZONE_COND_NAME(FULL),
 32	ZONE_COND_NAME(OFFLINE),
 33};
 34#undef ZONE_COND_NAME
 35
 36/**
 37 * blk_zone_cond_str - Return string XXX in BLK_ZONE_COND_XXX.
 38 * @zone_cond: BLK_ZONE_COND_XXX.
 39 *
 40 * Description: Centralize block layer function to convert BLK_ZONE_COND_XXX
 41 * into string format. Useful in the debugging and tracing zone conditions. For
 42 * invalid BLK_ZONE_COND_XXX it returns string "UNKNOWN".
 43 */
 44const char *blk_zone_cond_str(enum blk_zone_cond zone_cond)
 45{
 46	static const char *zone_cond_str = "UNKNOWN";
 47
 48	if (zone_cond < ARRAY_SIZE(zone_cond_name) && zone_cond_name[zone_cond])
 49		zone_cond_str = zone_cond_name[zone_cond];
 50
 51	return zone_cond_str;
 52}
 53EXPORT_SYMBOL_GPL(blk_zone_cond_str);
 54
 55static inline sector_t blk_zone_start(struct request_queue *q,
 56				      sector_t sector)
 57{
 58	sector_t zone_mask = blk_queue_zone_sectors(q) - 1;
 59
 60	return sector & ~zone_mask;
 61}
 62
 63/*
 64 * Return true if a request is a write requests that needs zone write locking.
 65 */
 66bool blk_req_needs_zone_write_lock(struct request *rq)
 67{
 68	if (!rq->q->seq_zones_wlock)
 69		return false;
 70
 71	if (blk_rq_is_passthrough(rq))
 72		return false;
 73
 74	switch (req_op(rq)) {
 75	case REQ_OP_WRITE_ZEROES:
 76	case REQ_OP_WRITE_SAME:
 77	case REQ_OP_WRITE:
 78		return blk_rq_zone_is_seq(rq);
 79	default:
 80		return false;
 81	}
 82}
 83EXPORT_SYMBOL_GPL(blk_req_needs_zone_write_lock);
 84
 85bool blk_req_zone_write_trylock(struct request *rq)
 86{
 87	unsigned int zno = blk_rq_zone_no(rq);
 88
 89	if (test_and_set_bit(zno, rq->q->seq_zones_wlock))
 90		return false;
 91
 92	WARN_ON_ONCE(rq->rq_flags & RQF_ZONE_WRITE_LOCKED);
 93	rq->rq_flags |= RQF_ZONE_WRITE_LOCKED;
 94
 95	return true;
 96}
 97EXPORT_SYMBOL_GPL(blk_req_zone_write_trylock);
 98
 99void __blk_req_zone_write_lock(struct request *rq)
100{
101	if (WARN_ON_ONCE(test_and_set_bit(blk_rq_zone_no(rq),
102					  rq->q->seq_zones_wlock)))
103		return;
104
105	WARN_ON_ONCE(rq->rq_flags & RQF_ZONE_WRITE_LOCKED);
106	rq->rq_flags |= RQF_ZONE_WRITE_LOCKED;
107}
108EXPORT_SYMBOL_GPL(__blk_req_zone_write_lock);
109
110void __blk_req_zone_write_unlock(struct request *rq)
111{
112	rq->rq_flags &= ~RQF_ZONE_WRITE_LOCKED;
113	if (rq->q->seq_zones_wlock)
114		WARN_ON_ONCE(!test_and_clear_bit(blk_rq_zone_no(rq),
115						 rq->q->seq_zones_wlock));
116}
117EXPORT_SYMBOL_GPL(__blk_req_zone_write_unlock);
118
119/**
120 * blkdev_nr_zones - Get number of zones
121 * @disk:	Target gendisk
122 *
123 * Return the total number of zones of a zoned block device.  For a block
124 * device without zone capabilities, the number of zones is always 0.
125 */
126unsigned int blkdev_nr_zones(struct gendisk *disk)
127{
128	sector_t zone_sectors = blk_queue_zone_sectors(disk->queue);
129
130	if (!blk_queue_is_zoned(disk->queue))
131		return 0;
132	return (get_capacity(disk) + zone_sectors - 1) >> ilog2(zone_sectors);
133}
134EXPORT_SYMBOL_GPL(blkdev_nr_zones);
135
136/**
137 * blkdev_report_zones - Get zones information
138 * @bdev:	Target block device
139 * @sector:	Sector from which to report zones
140 * @nr_zones:	Maximum number of zones to report
141 * @cb:		Callback function called for each reported zone
142 * @data:	Private data for the callback
143 *
144 * Description:
145 *    Get zone information starting from the zone containing @sector for at most
146 *    @nr_zones, and call @cb for each zone reported by the device.
147 *    To report all zones in a device starting from @sector, the BLK_ALL_ZONES
148 *    constant can be passed to @nr_zones.
149 *    Returns the number of zones reported by the device, or a negative errno
150 *    value in case of failure.
151 *
152 *    Note: The caller must use memalloc_noXX_save/restore() calls to control
153 *    memory allocations done within this function.
154 */
155int blkdev_report_zones(struct block_device *bdev, sector_t sector,
156			unsigned int nr_zones, report_zones_cb cb, void *data)
157{
158	struct gendisk *disk = bdev->bd_disk;
159	sector_t capacity = get_capacity(disk);
160
161	if (!blk_queue_is_zoned(bdev_get_queue(bdev)) ||
162	    WARN_ON_ONCE(!disk->fops->report_zones))
163		return -EOPNOTSUPP;
164
165	if (!nr_zones || sector >= capacity)
166		return 0;
167
168	return disk->fops->report_zones(disk, sector, nr_zones, cb, data);
169}
170EXPORT_SYMBOL_GPL(blkdev_report_zones);
171
172static inline bool blkdev_allow_reset_all_zones(struct block_device *bdev,
173						sector_t sector,
174						sector_t nr_sectors)
175{
176	if (!blk_queue_zone_resetall(bdev_get_queue(bdev)))
177		return false;
178
179	/*
180	 * REQ_OP_ZONE_RESET_ALL can be executed only if the number of sectors
181	 * of the applicable zone range is the entire disk.
182	 */
183	return !sector && nr_sectors == get_capacity(bdev->bd_disk);
184}
185
186/**
187 * blkdev_zone_mgmt - Execute a zone management operation on a range of zones
188 * @bdev:	Target block device
189 * @op:		Operation to be performed on the zones
190 * @sector:	Start sector of the first zone to operate on
191 * @nr_sectors:	Number of sectors, should be at least the length of one zone and
192 *		must be zone size aligned.
193 * @gfp_mask:	Memory allocation flags (for bio_alloc)
194 *
195 * Description:
196 *    Perform the specified operation on the range of zones specified by
197 *    @sector..@sector+@nr_sectors. Specifying the entire disk sector range
198 *    is valid, but the specified range should not contain conventional zones.
199 *    The operation to execute on each zone can be a zone reset, open, close
200 *    or finish request.
201 */
202int blkdev_zone_mgmt(struct block_device *bdev, enum req_opf op,
203		     sector_t sector, sector_t nr_sectors,
204		     gfp_t gfp_mask)
205{
206	struct request_queue *q = bdev_get_queue(bdev);
207	sector_t zone_sectors = blk_queue_zone_sectors(q);
208	sector_t capacity = get_capacity(bdev->bd_disk);
209	sector_t end_sector = sector + nr_sectors;
210	struct bio *bio = NULL;
211	int ret;
212
213	if (!blk_queue_is_zoned(q))
214		return -EOPNOTSUPP;
215
216	if (bdev_read_only(bdev))
217		return -EPERM;
218
219	if (!op_is_zone_mgmt(op))
220		return -EOPNOTSUPP;
221
222	if (end_sector <= sector || end_sector > capacity)
223		/* Out of range */
224		return -EINVAL;
225
226	/* Check alignment (handle eventual smaller last zone) */
227	if (sector & (zone_sectors - 1))
228		return -EINVAL;
229
230	if ((nr_sectors & (zone_sectors - 1)) && end_sector != capacity)
231		return -EINVAL;
232
233	while (sector < end_sector) {
234		bio = blk_next_bio(bio, 0, gfp_mask);
235		bio_set_dev(bio, bdev);
236
237		/*
238		 * Special case for the zone reset operation that reset all
239		 * zones, this is useful for applications like mkfs.
240		 */
241		if (op == REQ_OP_ZONE_RESET &&
242		    blkdev_allow_reset_all_zones(bdev, sector, nr_sectors)) {
243			bio->bi_opf = REQ_OP_ZONE_RESET_ALL;
244			break;
245		}
246
247		bio->bi_opf = op | REQ_SYNC;
248		bio->bi_iter.bi_sector = sector;
249		sector += zone_sectors;
250
251		/* This may take a while, so be nice to others */
252		cond_resched();
253	}
254
255	ret = submit_bio_wait(bio);
256	bio_put(bio);
257
258	return ret;
259}
260EXPORT_SYMBOL_GPL(blkdev_zone_mgmt);
261
262struct zone_report_args {
263	struct blk_zone __user *zones;
264};
265
266static int blkdev_copy_zone_to_user(struct blk_zone *zone, unsigned int idx,
267				    void *data)
268{
269	struct zone_report_args *args = data;
270
271	if (copy_to_user(&args->zones[idx], zone, sizeof(struct blk_zone)))
272		return -EFAULT;
273	return 0;
274}
275
276/*
277 * BLKREPORTZONE ioctl processing.
278 * Called from blkdev_ioctl.
279 */
280int blkdev_report_zones_ioctl(struct block_device *bdev, fmode_t mode,
281			      unsigned int cmd, unsigned long arg)
282{
283	void __user *argp = (void __user *)arg;
284	struct zone_report_args args;
285	struct request_queue *q;
286	struct blk_zone_report rep;
287	int ret;
288
289	if (!argp)
290		return -EINVAL;
291
292	q = bdev_get_queue(bdev);
293	if (!q)
294		return -ENXIO;
295
296	if (!blk_queue_is_zoned(q))
297		return -ENOTTY;
298
299	if (!capable(CAP_SYS_ADMIN))
300		return -EACCES;
301
302	if (copy_from_user(&rep, argp, sizeof(struct blk_zone_report)))
303		return -EFAULT;
304
305	if (!rep.nr_zones)
306		return -EINVAL;
307
308	args.zones = argp + sizeof(struct blk_zone_report);
309	ret = blkdev_report_zones(bdev, rep.sector, rep.nr_zones,
310				  blkdev_copy_zone_to_user, &args);
311	if (ret < 0)
312		return ret;
313
314	rep.nr_zones = ret;
315	rep.flags = BLK_ZONE_REP_CAPACITY;
316	if (copy_to_user(argp, &rep, sizeof(struct blk_zone_report)))
317		return -EFAULT;
318	return 0;
319}
320
321/*
322 * BLKRESETZONE, BLKOPENZONE, BLKCLOSEZONE and BLKFINISHZONE ioctl processing.
323 * Called from blkdev_ioctl.
324 */
325int blkdev_zone_mgmt_ioctl(struct block_device *bdev, fmode_t mode,
326			   unsigned int cmd, unsigned long arg)
327{
328	void __user *argp = (void __user *)arg;
329	struct request_queue *q;
330	struct blk_zone_range zrange;
331	enum req_opf op;
332
333	if (!argp)
334		return -EINVAL;
335
336	q = bdev_get_queue(bdev);
337	if (!q)
338		return -ENXIO;
339
340	if (!blk_queue_is_zoned(q))
341		return -ENOTTY;
342
343	if (!capable(CAP_SYS_ADMIN))
344		return -EACCES;
345
346	if (!(mode & FMODE_WRITE))
347		return -EBADF;
348
349	if (copy_from_user(&zrange, argp, sizeof(struct blk_zone_range)))
350		return -EFAULT;
351
352	switch (cmd) {
353	case BLKRESETZONE:
354		op = REQ_OP_ZONE_RESET;
355		break;
356	case BLKOPENZONE:
357		op = REQ_OP_ZONE_OPEN;
358		break;
359	case BLKCLOSEZONE:
360		op = REQ_OP_ZONE_CLOSE;
361		break;
362	case BLKFINISHZONE:
363		op = REQ_OP_ZONE_FINISH;
364		break;
365	default:
366		return -ENOTTY;
367	}
368
369	return blkdev_zone_mgmt(bdev, op, zrange.sector, zrange.nr_sectors,
370				GFP_KERNEL);
371}
372
373static inline unsigned long *blk_alloc_zone_bitmap(int node,
374						   unsigned int nr_zones)
375{
376	return kcalloc_node(BITS_TO_LONGS(nr_zones), sizeof(unsigned long),
377			    GFP_NOIO, node);
378}
379
380void blk_queue_free_zone_bitmaps(struct request_queue *q)
381{
382	kfree(q->conv_zones_bitmap);
383	q->conv_zones_bitmap = NULL;
384	kfree(q->seq_zones_wlock);
385	q->seq_zones_wlock = NULL;
386}
387
388struct blk_revalidate_zone_args {
389	struct gendisk	*disk;
390	unsigned long	*conv_zones_bitmap;
391	unsigned long	*seq_zones_wlock;
392	unsigned int	nr_zones;
393	sector_t	zone_sectors;
394	sector_t	sector;
395};
396
397/*
398 * Helper function to check the validity of zones of a zoned block device.
399 */
400static int blk_revalidate_zone_cb(struct blk_zone *zone, unsigned int idx,
401				  void *data)
402{
403	struct blk_revalidate_zone_args *args = data;
404	struct gendisk *disk = args->disk;
405	struct request_queue *q = disk->queue;
406	sector_t capacity = get_capacity(disk);
407
408	/*
409	 * All zones must have the same size, with the exception on an eventual
410	 * smaller last zone.
411	 */
412	if (zone->start == 0) {
413		if (zone->len == 0 || !is_power_of_2(zone->len)) {
414			pr_warn("%s: Invalid zoned device with non power of two zone size (%llu)\n",
415				disk->disk_name, zone->len);
416			return -ENODEV;
417		}
418
419		args->zone_sectors = zone->len;
420		args->nr_zones = (capacity + zone->len - 1) >> ilog2(zone->len);
421	} else if (zone->start + args->zone_sectors < capacity) {
422		if (zone->len != args->zone_sectors) {
423			pr_warn("%s: Invalid zoned device with non constant zone size\n",
424				disk->disk_name);
425			return -ENODEV;
426		}
427	} else {
428		if (zone->len > args->zone_sectors) {
429			pr_warn("%s: Invalid zoned device with larger last zone size\n",
430				disk->disk_name);
431			return -ENODEV;
432		}
433	}
434
435	/* Check for holes in the zone report */
436	if (zone->start != args->sector) {
437		pr_warn("%s: Zone gap at sectors %llu..%llu\n",
438			disk->disk_name, args->sector, zone->start);
439		return -ENODEV;
440	}
441
442	/* Check zone type */
443	switch (zone->type) {
444	case BLK_ZONE_TYPE_CONVENTIONAL:
445		if (!args->conv_zones_bitmap) {
446			args->conv_zones_bitmap =
447				blk_alloc_zone_bitmap(q->node, args->nr_zones);
448			if (!args->conv_zones_bitmap)
449				return -ENOMEM;
450		}
451		set_bit(idx, args->conv_zones_bitmap);
452		break;
453	case BLK_ZONE_TYPE_SEQWRITE_REQ:
454	case BLK_ZONE_TYPE_SEQWRITE_PREF:
455		if (!args->seq_zones_wlock) {
456			args->seq_zones_wlock =
457				blk_alloc_zone_bitmap(q->node, args->nr_zones);
458			if (!args->seq_zones_wlock)
459				return -ENOMEM;
460		}
461		break;
462	default:
463		pr_warn("%s: Invalid zone type 0x%x at sectors %llu\n",
464			disk->disk_name, (int)zone->type, zone->start);
465		return -ENODEV;
466	}
467
468	args->sector += zone->len;
469	return 0;
470}
471
472/**
473 * blk_revalidate_disk_zones - (re)allocate and initialize zone bitmaps
474 * @disk:	Target disk
475 * @update_driver_data:	Callback to update driver data on the frozen disk
476 *
477 * Helper function for low-level device drivers to (re) allocate and initialize
478 * a disk request queue zone bitmaps. This functions should normally be called
479 * within the disk ->revalidate method for blk-mq based drivers.  For BIO based
480 * drivers only q->nr_zones needs to be updated so that the sysfs exposed value
481 * is correct.
482 * If the @update_driver_data callback function is not NULL, the callback is
483 * executed with the device request queue frozen after all zones have been
484 * checked.
485 */
486int blk_revalidate_disk_zones(struct gendisk *disk,
487			      void (*update_driver_data)(struct gendisk *disk))
488{
489	struct request_queue *q = disk->queue;
490	struct blk_revalidate_zone_args args = {
491		.disk		= disk,
492	};
493	unsigned int noio_flag;
494	int ret;
495
496	if (WARN_ON_ONCE(!blk_queue_is_zoned(q)))
497		return -EIO;
498	if (WARN_ON_ONCE(!queue_is_mq(q)))
499		return -EIO;
500
501	if (!get_capacity(disk))
502		return -EIO;
503
504	/*
505	 * Ensure that all memory allocations in this context are done as if
506	 * GFP_NOIO was specified.
507	 */
508	noio_flag = memalloc_noio_save();
509	ret = disk->fops->report_zones(disk, 0, UINT_MAX,
510				       blk_revalidate_zone_cb, &args);
511	memalloc_noio_restore(noio_flag);
512
513	/*
514	 * Install the new bitmaps and update nr_zones only once the queue is
515	 * stopped and all I/Os are completed (i.e. a scheduler is not
516	 * referencing the bitmaps).
517	 */
518	blk_mq_freeze_queue(q);
519	if (ret >= 0) {
520		blk_queue_chunk_sectors(q, args.zone_sectors);
521		q->nr_zones = args.nr_zones;
522		swap(q->seq_zones_wlock, args.seq_zones_wlock);
523		swap(q->conv_zones_bitmap, args.conv_zones_bitmap);
524		if (update_driver_data)
525			update_driver_data(disk);
526		ret = 0;
527	} else {
528		pr_warn("%s: failed to revalidate zones\n", disk->disk_name);
529		blk_queue_free_zone_bitmaps(q);
530	}
531	blk_mq_unfreeze_queue(q);
532
533	kfree(args.seq_zones_wlock);
534	kfree(args.conv_zones_bitmap);
535	return ret;
536}
537EXPORT_SYMBOL_GPL(blk_revalidate_disk_zones);