[linux-2.6-block.git] / drivers / md / dm-stripe.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2001-2003 Sistina Software (UK) Limited.
 *
 * This file is released under the GPL.
 */

#include "dm.h"
#include <linux/device-mapper.h>

#include <linux/module.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <linux/bio.h>
#include <linux/dax.h>
#include <linux/slab.h>
#include <linux/log2.h>

static struct workqueue_struct *dm_stripe_wq;

#define DM_MSG_PREFIX "striped"
#define DM_IO_ERROR_THRESHOLD 15

struct stripe {
	struct dm_dev *dev;
	sector_t physical_start;

	atomic_t error_count;
};

struct stripe_c {
	uint32_t stripes;
	int stripes_shift;

	/* The size of this target / num. stripes */
	sector_t stripe_width;

	uint32_t chunk_size;
	int chunk_size_shift;

	/* Needed for handling events */
	struct dm_target *ti;

	/* Work struct used for triggering events*/
	struct work_struct trigger_event;

	struct stripe stripe[];
};

/*
 * An event is triggered whenever a drive
 * drops out of a stripe volume.
 */
static void trigger_event(struct work_struct *work)
{
	struct stripe_c *sc = container_of(work, struct stripe_c,
					   trigger_event);
	dm_table_event(sc->ti->table);
}

/*
 * Parse a single <dev> <sector> pair
 */
static int get_stripe(struct dm_target *ti, struct stripe_c *sc,
		      unsigned int stripe, char **argv)
{
	unsigned long long start;
	char dummy;
	int ret;

	if (sscanf(argv[1], "%llu%c", &start, &dummy) != 1)
		return -EINVAL;

	ret = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table),
			    &sc->stripe[stripe].dev);
	if (ret)
		return ret;

	sc->stripe[stripe].physical_start = start;

	return 0;
}

/*
 * Construct a striped mapping.
 * <number of stripes> <chunk size> [<dev_path> <offset>]+
 */
static int stripe_ctr(struct dm_target *ti, unsigned int argc, char **argv)
{
	struct stripe_c *sc;
	sector_t width, tmp_len;
	uint32_t stripes;
	uint32_t chunk_size;
	int r;
	unsigned int i;

	if (argc < 2) {
		ti->error = "Not enough arguments";
		return -EINVAL;
	}

	if (kstrtouint(argv[0], 10, &stripes) || !stripes) {
		ti->error = "Invalid stripe count";
		return -EINVAL;
	}

	if (kstrtouint(argv[1], 10, &chunk_size) || !chunk_size) {
		ti->error = "Invalid chunk_size";
		return -EINVAL;
	}

	width = ti->len;
	if (sector_div(width, stripes)) {
		ti->error = "Target length not divisible by number of stripes";
		return -EINVAL;
	}

	tmp_len = width;
	if (sector_div(tmp_len, chunk_size)) {
		ti->error = "Target length not divisible by chunk size";
		return -EINVAL;
	}

	/*
	 * Do we have enough arguments for that many stripes ?
	 */
	if (argc != (2 + 2 * stripes)) {
		ti->error = "Not enough destinations specified";
		return -EINVAL;
	}

	sc = kmalloc(struct_size(sc, stripe, stripes), GFP_KERNEL);
	if (!sc) {
		ti->error = "Memory allocation for striped context failed";
		return -ENOMEM;
	}

	INIT_WORK(&sc->trigger_event, trigger_event);

	/* Set pointer to dm target; used in trigger_event */
	sc->ti = ti;
	sc->stripes = stripes;
	sc->stripe_width = width;

	if (stripes & (stripes - 1))
		sc->stripes_shift = -1;
	else
		sc->stripes_shift = __ffs(stripes);

	r = dm_set_target_max_io_len(ti, chunk_size);
	if (r) {
		kfree(sc);
		return r;
	}

	ti->num_flush_bios = stripes;
	ti->num_discard_bios = stripes;
	ti->num_secure_erase_bios = stripes;
	ti->num_write_zeroes_bios = stripes;

	sc->chunk_size = chunk_size;
	if (chunk_size & (chunk_size - 1))
		sc->chunk_size_shift = -1;
	else
		sc->chunk_size_shift = __ffs(chunk_size);

	/*
	 * Get the stripe destinations.
	 */
	for (i = 0; i < stripes; i++) {
		argv += 2;

		r = get_stripe(ti, sc, i, argv);
		if (r < 0) {
			ti->error = "Couldn't parse stripe destination";
			while (i--)
				dm_put_device(ti, sc->stripe[i].dev);
			kfree(sc);
			return r;
		}
		atomic_set(&(sc->stripe[i].error_count), 0);
	}

	ti->private = sc;

	return 0;
}

static void stripe_dtr(struct dm_target *ti)
{
	unsigned int i;
	struct stripe_c *sc = ti->private;

	for (i = 0; i < sc->stripes; i++)
		dm_put_device(ti, sc->stripe[i].dev);

	flush_work(&sc->trigger_event);
	kfree(sc);
}

static void stripe_map_sector(struct stripe_c *sc, sector_t sector,
			      uint32_t *stripe, sector_t *result)
{
	sector_t chunk = dm_target_offset(sc->ti, sector);
	sector_t chunk_offset;

	if (sc->chunk_size_shift < 0)
		chunk_offset = sector_div(chunk, sc->chunk_size);
	else {
		chunk_offset = chunk & (sc->chunk_size - 1);
		chunk >>= sc->chunk_size_shift;
	}

	if (sc->stripes_shift < 0)
		*stripe = sector_div(chunk, sc->stripes);
	else {
		*stripe = chunk & (sc->stripes - 1);
		chunk >>= sc->stripes_shift;
	}

	if (sc->chunk_size_shift < 0)
		chunk *= sc->chunk_size;
	else
		chunk <<= sc->chunk_size_shift;

	*result = chunk + chunk_offset;
}

static void stripe_map_range_sector(struct stripe_c *sc, sector_t sector,
				    uint32_t target_stripe, sector_t *result)
{
	uint32_t stripe;

	stripe_map_sector(sc, sector, &stripe, result);
	if (stripe == target_stripe)
		return;

	/* round down */
	sector = *result;
	if (sc->chunk_size_shift < 0)
		*result -= sector_div(sector, sc->chunk_size);
	else
		*result = sector & ~(sector_t)(sc->chunk_size - 1);

	if (target_stripe < stripe)
		*result += sc->chunk_size;		/* next chunk */
}

static int stripe_map_range(struct stripe_c *sc, struct bio *bio,
			    uint32_t target_stripe)
{
	sector_t begin, end;

	stripe_map_range_sector(sc, bio->bi_iter.bi_sector,
				target_stripe, &begin);
	stripe_map_range_sector(sc, bio_end_sector(bio),
				target_stripe, &end);
	if (begin < end) {
		bio_set_dev(bio, sc->stripe[target_stripe].dev->bdev);
		bio->bi_iter.bi_sector = begin +
			sc->stripe[target_stripe].physical_start;
		bio->bi_iter.bi_size = to_bytes(end - begin);
		return DM_MAPIO_REMAPPED;
	}

	/* The range doesn't map to the target stripe */
	bio_endio(bio);
	return DM_MAPIO_SUBMITTED;
}

static int stripe_map(struct dm_target *ti, struct bio *bio)
{
	struct stripe_c *sc = ti->private;
	uint32_t stripe;
	unsigned int target_bio_nr;

	if (bio->bi_opf & REQ_PREFLUSH) {
		target_bio_nr = dm_bio_get_target_bio_nr(bio);
		BUG_ON(target_bio_nr >= sc->stripes);
		bio_set_dev(bio, sc->stripe[target_bio_nr].dev->bdev);
		return DM_MAPIO_REMAPPED;
	}
	if (unlikely(bio_op(bio) == REQ_OP_DISCARD) ||
	    unlikely(bio_op(bio) == REQ_OP_SECURE_ERASE) ||
	    unlikely(bio_op(bio) == REQ_OP_WRITE_ZEROES)) {
		target_bio_nr = dm_bio_get_target_bio_nr(bio);
		BUG_ON(target_bio_nr >= sc->stripes);
		return stripe_map_range(sc, bio, target_bio_nr);
	}

	stripe_map_sector(sc, bio->bi_iter.bi_sector,
			  &stripe, &bio->bi_iter.bi_sector);

	bio->bi_iter.bi_sector += sc->stripe[stripe].physical_start;
	bio_set_dev(bio, sc->stripe[stripe].dev->bdev);

	return DM_MAPIO_REMAPPED;
}

#if IS_ENABLED(CONFIG_FS_DAX)
static struct dax_device *stripe_dax_pgoff(struct dm_target *ti, pgoff_t *pgoff)
{
	struct stripe_c *sc = ti->private;
	struct block_device *bdev;
	sector_t dev_sector;
	uint32_t stripe;

	stripe_map_sector(sc, *pgoff * PAGE_SECTORS, &stripe, &dev_sector);
	dev_sector += sc->stripe[stripe].physical_start;
	bdev = sc->stripe[stripe].dev->bdev;

	*pgoff = (get_start_sect(bdev) + dev_sector) >> PAGE_SECTORS_SHIFT;
	return sc->stripe[stripe].dev->dax_dev;
}

static long stripe_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,
		long nr_pages, enum dax_access_mode mode, void **kaddr,
		pfn_t *pfn)
{
	struct dax_device *dax_dev = stripe_dax_pgoff(ti, &pgoff);

	return dax_direct_access(dax_dev, pgoff, nr_pages, mode, kaddr, pfn);
}

static int stripe_dax_zero_page_range(struct dm_target *ti, pgoff_t pgoff,
				      size_t nr_pages)
{
	struct dax_device *dax_dev = stripe_dax_pgoff(ti, &pgoff);

	return dax_zero_page_range(dax_dev, pgoff, nr_pages);
}

static size_t stripe_dax_recovery_write(struct dm_target *ti, pgoff_t pgoff,
		void *addr, size_t bytes, struct iov_iter *i)
{
	struct dax_device *dax_dev = stripe_dax_pgoff(ti, &pgoff);

	return dax_recovery_write(dax_dev, pgoff, addr, bytes, i);
}

#else
#define stripe_dax_direct_access NULL
#define stripe_dax_zero_page_range NULL
#define stripe_dax_recovery_write NULL
#endif

/*
 * Stripe status:
 *
 * INFO
 * #stripes [stripe_name <stripe_name>] [group word count]
 * [error count 'A|D' <error count 'A|D'>]
 *
 * TABLE
 * #stripes [stripe chunk size]
 * [stripe_name physical_start <stripe_name physical_start>]
 *
 */

static void stripe_status(struct dm_target *ti, status_type_t type,
			  unsigned int status_flags, char *result, unsigned int maxlen)
{
	struct stripe_c *sc = ti->private;
	unsigned int sz = 0;
	unsigned int i;

	switch (type) {
	case STATUSTYPE_INFO:
		DMEMIT("%d ", sc->stripes);
		for (i = 0; i < sc->stripes; i++)
			DMEMIT("%s ", sc->stripe[i].dev->name);

		DMEMIT("1 ");
		for (i = 0; i < sc->stripes; i++)
			DMEMIT("%c", atomic_read(&(sc->stripe[i].error_count)) ?  'D' : 'A');
		break;

	case STATUSTYPE_TABLE:
		DMEMIT("%d %llu", sc->stripes,
			(unsigned long long)sc->chunk_size);
		for (i = 0; i < sc->stripes; i++)
			DMEMIT(" %s %llu", sc->stripe[i].dev->name,
			    (unsigned long long)sc->stripe[i].physical_start);
		break;

	case STATUSTYPE_IMA:
		DMEMIT_TARGET_NAME_VERSION(ti->type);
		DMEMIT(",stripes=%d,chunk_size=%llu", sc->stripes,
		       (unsigned long long)sc->chunk_size);

		for (i = 0; i < sc->stripes; i++) {
			DMEMIT(",stripe_%d_device_name=%s", i, sc->stripe[i].dev->name);
			DMEMIT(",stripe_%d_physical_start=%llu", i,
			       (unsigned long long)sc->stripe[i].physical_start);
			DMEMIT(",stripe_%d_status=%c", i,
			       atomic_read(&(sc->stripe[i].error_count)) ? 'D' : 'A');
		}
		DMEMIT(";");
		break;
	}
}

static int stripe_end_io(struct dm_target *ti, struct bio *bio,
		blk_status_t *error)
{
	unsigned int i;
	char major_minor[16];
	struct stripe_c *sc = ti->private;

	if (!*error)
		return DM_ENDIO_DONE; /* I/O complete */

	if (bio->bi_opf & REQ_RAHEAD)
		return DM_ENDIO_DONE;

	if (*error == BLK_STS_NOTSUPP)
		return DM_ENDIO_DONE;

	memset(major_minor, 0, sizeof(major_minor));
	sprintf(major_minor, "%d:%d", MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)));

	/*
	 * Test to see which stripe drive triggered the event
	 * and increment error count for all stripes on that device.
	 * If the error count for a given device exceeds the threshold
	 * value we will no longer trigger any further events.
	 */
	for (i = 0; i < sc->stripes; i++)
		if (!strcmp(sc->stripe[i].dev->name, major_minor)) {
			atomic_inc(&(sc->stripe[i].error_count));
			if (atomic_read(&(sc->stripe[i].error_count)) <
			    DM_IO_ERROR_THRESHOLD)
				queue_work(dm_stripe_wq, &sc->trigger_event);
		}

	return DM_ENDIO_DONE;
}

static int stripe_iterate_devices(struct dm_target *ti,
				  iterate_devices_callout_fn fn, void *data)
{
	struct stripe_c *sc = ti->private;
	int ret = 0;
	unsigned int i = 0;

	do {
		ret = fn(ti, sc->stripe[i].dev,
			 sc->stripe[i].physical_start,
			 sc->stripe_width, data);
	} while (!ret && ++i < sc->stripes);

	return ret;
}

static void stripe_io_hints(struct dm_target *ti,
			    struct queue_limits *limits)
{
	struct stripe_c *sc = ti->private;
	unsigned int chunk_size = sc->chunk_size << SECTOR_SHIFT;

	blk_limits_io_min(limits, chunk_size);
	blk_limits_io_opt(limits, chunk_size * sc->stripes);
}

static struct target_type stripe_target = {
	.name   = "striped",
	.version = {1, 6, 0},
	.features = DM_TARGET_PASSES_INTEGRITY | DM_TARGET_NOWAIT,
	.module = THIS_MODULE,
	.ctr    = stripe_ctr,
	.dtr    = stripe_dtr,
	.map    = stripe_map,
	.end_io = stripe_end_io,
	.status = stripe_status,
	.iterate_devices = stripe_iterate_devices,
	.io_hints = stripe_io_hints,
	.direct_access = stripe_dax_direct_access,
	.dax_zero_page_range = stripe_dax_zero_page_range,
	.dax_recovery_write = stripe_dax_recovery_write,
};

int __init dm_stripe_init(void)
{
	int r;

	dm_stripe_wq = alloc_workqueue("dm_stripe_wq", 0, 0);
	if (!dm_stripe_wq)
		return -ENOMEM;
	r = dm_register_target(&stripe_target);
	if (r < 0) {
		destroy_workqueue(dm_stripe_wq);
		DMWARN("target registration failed");
	}

	return r;
}

void dm_stripe_exit(void)
{
	dm_unregister_target(&stripe_target);
	destroy_workqueue(dm_stripe_wq);
}
Commit	Line	Data
3bd94003	1	// SPDX-License-Identifier: GPL-2.0-only
1da177e4 LT	2	/*
	3	* Copyright (C) 2001-2003 Sistina Software (UK) Limited.
	4	*
	5	* This file is released under the GPL.
	6	*/
	7
7fff5e8f	8	#include "dm.h"
586e80e6	9	#include <linux/device-mapper.h>
1da177e4 LT	10
	11	#include <linux/module.h>
	12	#include <linux/init.h>
	13	#include <linux/blkdev.h>
	14	#include <linux/bio.h>
817bf402	15	#include <linux/dax.h>
1da177e4	16	#include <linux/slab.h>
6f3c3f0a	17	#include <linux/log2.h>
1da177e4	18
a7e8f7fb TH	19	static struct workqueue_struct *dm_stripe_wq;
a7e8f7fb TH	20
72d94861	21	#define DM_MSG_PREFIX "striped"
a25eb944	22	#define DM_IO_ERROR_THRESHOLD 15
72d94861	23
1da177e4 LT	24	struct stripe {
	25	struct dm_dev *dev;
	26	sector_t physical_start;
a25eb944 BW	27
a25eb944 BW	28	atomic_t error_count;
1da177e4 LT	29	};
	30
	31	struct stripe_c {
	32	uint32_t stripes;
c96053b7	33	int stripes_shift;
1da177e4 LT	34
	35	/* The size of this target / num. stripes */
	36	sector_t stripe_width;
	37
eb850de6	38	uint32_t chunk_size;
33d07c0d	39	int chunk_size_shift;
1da177e4	40
a25eb944 BW	41	/* Needed for handling events */
	42	struct dm_target *ti;
	43
	44	/* Work struct used for triggering events*/
f521f074	45	struct work_struct trigger_event;
a25eb944	46
b18ae8dd	47	struct stripe stripe[];
1da177e4 LT	48	};
1da177e4 LT	49
a25eb944 BW	50	/*
	51	* An event is triggered whenever a drive
	52	* drops out of a stripe volume.
	53	*/
	54	static void trigger_event(struct work_struct *work)
	55	{
f521f074 TH	56	struct stripe_c *sc = container_of(work, struct stripe_c,
f521f074 TH	57	trigger_event);
a25eb944	58	dm_table_event(sc->ti->table);
a25eb944 BW	59	}
a25eb944 BW	60
1da177e4 LT	61	/*
	62	* Parse a single <dev> <sector> pair
	63	*/
	64	static int get_stripe(struct dm_target ti, struct stripe_c sc,
	65	unsigned int stripe, char **argv)
	66	{
4ee218cd	67	unsigned long long start;
31998ef1	68	char dummy;
e80d1c80	69	int ret;
1da177e4	70
31998ef1	71	if (sscanf(argv[1], "%llu%c", &start, &dummy) != 1)
1da177e4 LT	72	return -EINVAL;
1da177e4 LT	73
e80d1c80 VG	74	ret = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table),
	75	&sc->stripe[stripe].dev);
	76	if (ret)
	77	return ret;
1da177e4 LT	78
1da177e4 LT	79	sc->stripe[stripe].physical_start = start;
a25eb944	80
1da177e4 LT	81	return 0;
	82	}
	83
	84	/*
	85	* Construct a striped mapping.
eb850de6	86	* <number of stripes> <chunk size> [<dev_path> <offset>]+
1da177e4 LT	87	*/
	88	static int stripe_ctr(struct dm_target ti, unsigned int argc, char *argv)
	89	{
	90	struct stripe_c *sc;
d793e684	91	sector_t width, tmp_len;
1da177e4 LT	92	uint32_t stripes;
1da177e4 LT	93	uint32_t chunk_size;
1da177e4 LT	94	int r;
	95	unsigned int i;
	96
	97	if (argc < 2) {
72d94861	98	ti->error = "Not enough arguments";
1da177e4 LT	99	return -EINVAL;
	100	}
	101
1a66a08a	102	if (kstrtouint(argv[0], 10, &stripes) \|\| !stripes) {
72d94861	103	ti->error = "Invalid stripe count";
1da177e4 LT	104	return -EINVAL;
	105	}
	106
8f069b41	107	if (kstrtouint(argv[1], 10, &chunk_size) \|\| !chunk_size) {
eb850de6	108	ti->error = "Invalid chunk_size";
1da177e4 LT	109	return -EINVAL;
	110	}
	111
eb850de6	112	width = ti->len;
d793e684	113	if (sector_div(width, stripes)) {
2e84fecf	114	ti->error = "Target length not divisible by number of stripes";
8ba32fde KC	115	return -EINVAL;
	116	}
	117
d793e684 MS	118	tmp_len = width;
d793e684 MS	119	if (sector_div(tmp_len, chunk_size)) {
2e84fecf	120	ti->error = "Target length not divisible by chunk size";
1da177e4 LT	121	return -EINVAL;
	122	}
	123
	124	/*
	125	* Do we have enough arguments for that many stripes ?
	126	*/
	127	if (argc != (2 + 2 * stripes)) {
2e84fecf	128	ti->error = "Not enough destinations specified";
1da177e4 LT	129	return -EINVAL;
	130	}
	131
8adeac3b	132	sc = kmalloc(struct_size(sc, stripe, stripes), GFP_KERNEL);
1da177e4	133	if (!sc) {
2e84fecf	134	ti->error = "Memory allocation for striped context failed";
1da177e4 LT	135	return -ENOMEM;
	136	}
	137
f521f074	138	INIT_WORK(&sc->trigger_event, trigger_event);
a25eb944 BW	139
	140	/* Set pointer to dm target; used in trigger_event */
	141	sc->ti = ti;
1da177e4 LT	142	sc->stripes = stripes;
1da177e4 LT	143	sc->stripe_width = width;
c96053b7 MP	144
	145	if (stripes & (stripes - 1))
	146	sc->stripes_shift = -1;
1df05483 MP	147	else
1df05483 MP	148	sc->stripes_shift = __ffs(stripes);
c96053b7	149
542f9038	150	r = dm_set_target_max_io_len(ti, chunk_size);
a3f2af25 PK	151	if (r) {
a3f2af25 PK	152	kfree(sc);
542f9038	153	return r;
a3f2af25	154	}
542f9038	155
55a62eef AK	156	ti->num_flush_bios = stripes;
55a62eef AK	157	ti->num_discard_bios = stripes;
00716545	158	ti->num_secure_erase_bios = stripes;
ac62d620	159	ti->num_write_zeroes_bios = stripes;
1da177e4	160
eb850de6	161	sc->chunk_size = chunk_size;
33d07c0d MP	162	if (chunk_size & (chunk_size - 1))
	163	sc->chunk_size_shift = -1;
	164	else
	165	sc->chunk_size_shift = __ffs(chunk_size);
1da177e4 LT	166
	167	/*
	168	* Get the stripe destinations.
	169	*/
	170	for (i = 0; i < stripes; i++) {
	171	argv += 2;
	172
	173	r = get_stripe(ti, sc, i, argv);
	174	if (r < 0) {
72d94861	175	ti->error = "Couldn't parse stripe destination";
1da177e4 LT	176	while (i--)
	177	dm_put_device(ti, sc->stripe[i].dev);
	178	kfree(sc);
	179	return r;
	180	}
a25eb944	181	atomic_set(&(sc->stripe[i].error_count), 0);
1da177e4 LT	182	}
	183
	184	ti->private = sc;
a25eb944	185
1da177e4 LT	186	return 0;
	187	}
	188
	189	static void stripe_dtr(struct dm_target *ti)
	190	{
	191	unsigned int i;
26cb62a2	192	struct stripe_c *sc = ti->private;
1da177e4 LT	193
	194	for (i = 0; i < sc->stripes; i++)
	195	dm_put_device(ti, sc->stripe[i].dev);
	196
43829731	197	flush_work(&sc->trigger_event);
1da177e4 LT	198	kfree(sc);
	199	}
	200
65988525 MP	201	static void stripe_map_sector(struct stripe_c *sc, sector_t sector,
	202	uint32_t stripe, sector_t result)
	203	{
eb850de6	204	sector_t chunk = dm_target_offset(sc->ti, sector);
33d07c0d MP	205	sector_t chunk_offset;
	206
	207	if (sc->chunk_size_shift < 0)
	208	chunk_offset = sector_div(chunk, sc->chunk_size);
	209	else {
	210	chunk_offset = chunk & (sc->chunk_size - 1);
	211	chunk >>= sc->chunk_size_shift;
	212	}
65988525	213
c96053b7 MP	214	if (sc->stripes_shift < 0)
	215	*stripe = sector_div(chunk, sc->stripes);
	216	else {
1df05483	217	*stripe = chunk & (sc->stripes - 1);
c96053b7 MP	218	chunk >>= sc->stripes_shift;
	219	}
	220
33d07c0d MP	221	if (sc->chunk_size_shift < 0)
	222	chunk *= sc->chunk_size;
	223	else
	224	chunk <<= sc->chunk_size_shift;
	225
	226	*result = chunk + chunk_offset;
65988525 MP	227	}
65988525 MP	228
7b76ec11 MP	229	static void stripe_map_range_sector(struct stripe_c *sc, sector_t sector,
	230	uint32_t target_stripe, sector_t *result)
	231	{
	232	uint32_t stripe;
	233
	234	stripe_map_sector(sc, sector, &stripe, result);
	235	if (stripe == target_stripe)
	236	return;
eb850de6 MS	237
	238	/* round down */
	239	sector = *result;
33d07c0d MP	240	if (sc->chunk_size_shift < 0)
	241	*result -= sector_div(sector, sc->chunk_size);
	242	else
	243	*result = sector & ~(sector_t)(sc->chunk_size - 1);
eb850de6	244
7b76ec11	245	if (target_stripe < stripe)
eb850de6	246	result += sc->chunk_size; / next chunk */
7b76ec11 MP	247	}
7b76ec11 MP	248
45e621d4 MS	249	static int stripe_map_range(struct stripe_c sc, struct bio bio,
45e621d4 MS	250	uint32_t target_stripe)
7b76ec11 MP	251	{
	252	sector_t begin, end;
	253
4f024f37 KO	254	stripe_map_range_sector(sc, bio->bi_iter.bi_sector,
4f024f37 KO	255	target_stripe, &begin);
f73a1c7d	256	stripe_map_range_sector(sc, bio_end_sector(bio),
7b76ec11 MP	257	target_stripe, &end);
7b76ec11 MP	258	if (begin < end) {
74d46992	259	bio_set_dev(bio, sc->stripe[target_stripe].dev->bdev);
4f024f37 KO	260	bio->bi_iter.bi_sector = begin +
	261	sc->stripe[target_stripe].physical_start;
	262	bio->bi_iter.bi_size = to_bytes(end - begin);
7b76ec11	263	return DM_MAPIO_REMAPPED;
7b76ec11	264	}
1c3fe2fa HM	265
	266	/* The range doesn't map to the target stripe */
	267	bio_endio(bio);
	268	return DM_MAPIO_SUBMITTED;
7b76ec11 MP	269	}
7b76ec11 MP	270
7de3ee57	271	static int stripe_map(struct dm_target ti, struct bio bio)
1da177e4	272	{
65988525	273	struct stripe_c *sc = ti->private;
374bf7e7	274	uint32_t stripe;
86a3238c	275	unsigned int target_bio_nr;
1da177e4	276
1eff9d32	277	if (bio->bi_opf & REQ_PREFLUSH) {
55a62eef AK	278	target_bio_nr = dm_bio_get_target_bio_nr(bio);
55a62eef AK	279	BUG_ON(target_bio_nr >= sc->stripes);
74d46992	280	bio_set_dev(bio, sc->stripe[target_bio_nr].dev->bdev);
374bf7e7 MP	281	return DM_MAPIO_REMAPPED;
374bf7e7 MP	282	}
e6047149	283	if (unlikely(bio_op(bio) == REQ_OP_DISCARD) \|\|
00716545	284	unlikely(bio_op(bio) == REQ_OP_SECURE_ERASE) \|\|
a773187e	285	unlikely(bio_op(bio) == REQ_OP_WRITE_ZEROES)) {
55a62eef AK	286	target_bio_nr = dm_bio_get_target_bio_nr(bio);
	287	BUG_ON(target_bio_nr >= sc->stripes);
	288	return stripe_map_range(sc, bio, target_bio_nr);
7b76ec11	289	}
374bf7e7	290
4f024f37 KO	291	stripe_map_sector(sc, bio->bi_iter.bi_sector,
4f024f37 KO	292	&stripe, &bio->bi_iter.bi_sector);
1da177e4	293
4f024f37	294	bio->bi_iter.bi_sector += sc->stripe[stripe].physical_start;
74d46992	295	bio_set_dev(bio, sc->stripe[stripe].dev->bdev);
65988525	296
d2a7ad29	297	return DM_MAPIO_REMAPPED;
1da177e4 LT	298	}
1da177e4 LT	299
5d2a228b	300	#if IS_ENABLED(CONFIG_FS_DAX)
2a68553e	301	static struct dax_device stripe_dax_pgoff(struct dm_target ti, pgoff_t *pgoff)
beec25b4 TK	302	{
beec25b4 TK	303	struct stripe_c *sc = ti->private;
beec25b4	304	struct block_device *bdev;
2a68553e	305	sector_t dev_sector;
817bf402	306	uint32_t stripe;
beec25b4	307
2a68553e	308	stripe_map_sector(sc, pgoff PAGE_SECTORS, &stripe, &dev_sector);
817bf402	309	dev_sector += sc->stripe[stripe].physical_start;
beec25b4 TK	310	bdev = sc->stripe[stripe].dev->bdev;
beec25b4 TK	311
2a68553e CH	312	*pgoff = (get_start_sect(bdev) + dev_sector) >> PAGE_SECTORS_SHIFT;
	313	return sc->stripe[stripe].dev->dax_dev;
	314	}
	315
	316	static long stripe_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,
e511c4a3 JC	317	long nr_pages, enum dax_access_mode mode, void **kaddr,
e511c4a3 JC	318	pfn_t *pfn)
2a68553e CH	319	{
	320	struct dax_device *dax_dev = stripe_dax_pgoff(ti, &pgoff);
	321
e511c4a3	322	return dax_direct_access(dax_dev, pgoff, nr_pages, mode, kaddr, pfn);
beec25b4 TK	323	}
beec25b4 TK	324
cdf6cdcd VG	325	static int stripe_dax_zero_page_range(struct dm_target *ti, pgoff_t pgoff,
	326	size_t nr_pages)
	327	{
2a68553e	328	struct dax_device *dax_dev = stripe_dax_pgoff(ti, &pgoff);
cdf6cdcd	329
cdf6cdcd VG	330	return dax_zero_page_range(dax_dev, pgoff, nr_pages);
	331	}
	332
047218ec JC	333	static size_t stripe_dax_recovery_write(struct dm_target *ti, pgoff_t pgoff,
	334	void addr, size_t bytes, struct iov_iter i)
	335	{
	336	struct dax_device *dax_dev = stripe_dax_pgoff(ti, &pgoff);
	337
	338	return dax_recovery_write(dax_dev, pgoff, addr, bytes, i);
	339	}
	340
976431b0 DW	341	#else
976431b0 DW	342	#define stripe_dax_direct_access NULL
cdf6cdcd	343	#define stripe_dax_zero_page_range NULL
047218ec	344	#define stripe_dax_recovery_write NULL
976431b0 DW	345	#endif
976431b0 DW	346
4f7f5c67 BW	347	/*
	348	* Stripe status:
	349	*
	350	* INFO
	351	* #stripes [stripe_name <stripe_name>] [group word count]
	352	* [error count 'A\|D' <error count 'A\|D'>]
	353	*
	354	* TABLE
	355	* #stripes [stripe chunk size]
	356	* [stripe_name physical_start <stripe_name physical_start>]
	357	*
	358	*/
	359
fd7c092e	360	static void stripe_status(struct dm_target *ti, status_type_t type,
86a3238c	361	unsigned int status_flags, char *result, unsigned int maxlen)
1da177e4	362	{
26cb62a2	363	struct stripe_c *sc = ti->private;
1da177e4 LT	364	unsigned int sz = 0;
	365	unsigned int i;
	366
	367	switch (type) {
	368	case STATUSTYPE_INFO:
4f7f5c67	369	DMEMIT("%d ", sc->stripes);
2d0f25cb	370	for (i = 0; i < sc->stripes; i++)
4f7f5c67	371	DMEMIT("%s ", sc->stripe[i].dev->name);
2d0f25cb	372
706dd22f	373	DMEMIT("1 ");
2d0f25cb HM	374	for (i = 0; i < sc->stripes; i++)
2d0f25cb HM	375	DMEMIT("%c", atomic_read(&(sc->stripe[i].error_count)) ? 'D' : 'A');
1da177e4 LT	376	break;
	377
	378	case STATUSTYPE_TABLE:
4ee218cd	379	DMEMIT("%d %llu", sc->stripes,
eb850de6	380	(unsigned long long)sc->chunk_size);
1da177e4	381	for (i = 0; i < sc->stripes; i++)
4ee218cd AM	382	DMEMIT(" %s %llu", sc->stripe[i].dev->name,
4ee218cd AM	383	(unsigned long long)sc->stripe[i].physical_start);
1da177e4	384	break;
8ec45662 TS	385
	386	case STATUSTYPE_IMA:
	387	DMEMIT_TARGET_NAME_VERSION(ti->type);
	388	DMEMIT(",stripes=%d,chunk_size=%llu", sc->stripes,
	389	(unsigned long long)sc->chunk_size);
	390
	391	for (i = 0; i < sc->stripes; i++) {
	392	DMEMIT(",stripe_%d_device_name=%s", i, sc->stripe[i].dev->name);
	393	DMEMIT(",stripe_%d_physical_start=%llu", i,
	394	(unsigned long long)sc->stripe[i].physical_start);
	395	DMEMIT(",stripe_%d_status=%c", i,
	396	atomic_read(&(sc->stripe[i].error_count)) ? 'D' : 'A');
	397	}
	398	DMEMIT(";");
	399	break;
1da177e4	400	}
1da177e4 LT	401	}
1da177e4 LT	402
4e4cbee9 CH	403	static int stripe_end_io(struct dm_target ti, struct bio bio,
4e4cbee9 CH	404	blk_status_t *error)
a25eb944	405	{
86a3238c	406	unsigned int i;
a25eb944 BW	407	char major_minor[16];
	408	struct stripe_c *sc = ti->private;
	409
1be56909 CH	410	if (!*error)
1be56909 CH	411	return DM_ENDIO_DONE; /* I/O complete */
a25eb944	412
9966afaf	413	if (bio->bi_opf & REQ_RAHEAD)
1be56909	414	return DM_ENDIO_DONE;
a25eb944	415
4e4cbee9	416	if (*error == BLK_STS_NOTSUPP)
1be56909	417	return DM_ENDIO_DONE;
a25eb944 BW	418
a25eb944 BW	419	memset(major_minor, 0, sizeof(major_minor));
74d46992	420	sprintf(major_minor, "%d:%d", MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)));
a25eb944 BW	421
	422	/*
	423	* Test to see which stripe drive triggered the event
	424	* and increment error count for all stripes on that device.
	425	* If the error count for a given device exceeds the threshold
	426	* value we will no longer trigger any further events.
	427	*/
	428	for (i = 0; i < sc->stripes; i++)
	429	if (!strcmp(sc->stripe[i].dev->name, major_minor)) {
	430	atomic_inc(&(sc->stripe[i].error_count));
	431	if (atomic_read(&(sc->stripe[i].error_count)) <
	432	DM_IO_ERROR_THRESHOLD)
a7e8f7fb	433	queue_work(dm_stripe_wq, &sc->trigger_event);
a25eb944 BW	434	}
a25eb944 BW	435
1be56909	436	return DM_ENDIO_DONE;
a25eb944 BW	437	}
a25eb944 BW	438
af4874e0 MS	439	static int stripe_iterate_devices(struct dm_target *ti,
	440	iterate_devices_callout_fn fn, void *data)
	441	{
	442	struct stripe_c *sc = ti->private;
	443	int ret = 0;
86a3238c	444	unsigned int i = 0;
af4874e0	445
5dea271b	446	do {
af4874e0	447	ret = fn(ti, sc->stripe[i].dev,
5dea271b MS	448	sc->stripe[i].physical_start,
	449	sc->stripe_width, data);
	450	} while (!ret && ++i < sc->stripes);
af4874e0 MS	451
	452	return ret;
	453	}
	454
40bea431 MS	455	static void stripe_io_hints(struct dm_target *ti,
	456	struct queue_limits *limits)
	457	{
	458	struct stripe_c *sc = ti->private;
86a3238c	459	unsigned int chunk_size = sc->chunk_size << SECTOR_SHIFT;
40bea431 MS	460
40bea431 MS	461	blk_limits_io_min(limits, chunk_size);
3c5820c7	462	blk_limits_io_opt(limits, chunk_size * sc->stripes);
40bea431 MS	463	}
40bea431 MS	464
1da177e4 LT	465	static struct target_type stripe_target = {
1da177e4 LT	466	.name = "striped",
beec25b4	467	.version = {1, 6, 0},
410fe220	468	.features = DM_TARGET_PASSES_INTEGRITY \| DM_TARGET_NOWAIT,
1da177e4 LT	469	.module = THIS_MODULE,
	470	.ctr = stripe_ctr,
	471	.dtr = stripe_dtr,
	472	.map = stripe_map,
a25eb944	473	.end_io = stripe_end_io,
1da177e4	474	.status = stripe_status,
af4874e0	475	.iterate_devices = stripe_iterate_devices,
40bea431	476	.io_hints = stripe_io_hints,
817bf402	477	.direct_access = stripe_dax_direct_access,
cdf6cdcd	478	.dax_zero_page_range = stripe_dax_zero_page_range,
047218ec	479	.dax_recovery_write = stripe_dax_recovery_write,
1da177e4 LT	480	};
	481
	482	int __init dm_stripe_init(void)
	483	{
	484	int r;
	485
a7e8f7fb TH	486	dm_stripe_wq = alloc_workqueue("dm_stripe_wq", 0, 0);
	487	if (!dm_stripe_wq)
	488	return -ENOMEM;
1da177e4	489	r = dm_register_target(&stripe_target);
a7e8f7fb TH	490	if (r < 0) {
a7e8f7fb TH	491	destroy_workqueue(dm_stripe_wq);
72d94861	492	DMWARN("target registration failed");
a7e8f7fb	493	}
1da177e4 LT	494
	495	return r;
	496	}
	497
	498	void dm_stripe_exit(void)
	499	{
10d3bd09	500	dm_unregister_target(&stripe_target);
a7e8f7fb	501	destroy_workqueue(dm_stripe_wq);
1da177e4	502	}