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

/*
 * Copyright (C) 2001-2003 Sistina Software (UK) Limited.
 *
 * This file is released under the GPL.
 */

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

#define DM_MSG_PREFIX "linear"

/*
 * Linear: maps a linear range of a device.
 */
struct linear_c {
	struct dm_dev *dev;
	sector_t start;
};

/*
 * Construct a linear mapping: <dev_path> <offset>
 */
static int linear_ctr(struct dm_target *ti, unsigned int argc, char **argv)
{
	struct linear_c *lc;
	unsigned long long tmp;
	char dummy;
	int ret;

	if (argc != 2) {
		ti->error = "Invalid argument count";
		return -EINVAL;
	}

	lc = kmalloc(sizeof(*lc), GFP_KERNEL);
	if (lc == NULL) {
		ti->error = "Cannot allocate linear context";
		return -ENOMEM;
	}

	ret = -EINVAL;
	if (sscanf(argv[1], "%llu%c", &tmp, &dummy) != 1 || tmp != (sector_t)tmp) {
		ti->error = "Invalid device sector";
		goto bad;
	}
	lc->start = tmp;

	ret = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &lc->dev);
	if (ret) {
		ti->error = "Device lookup failed";
		goto bad;
	}

	ti->num_flush_bios = 1;
	ti->num_discard_bios = 1;
	ti->num_secure_erase_bios = 1;
	ti->num_write_same_bios = 1;
	ti->num_write_zeroes_bios = 1;
	ti->private = lc;
	return 0;

      bad:
	kfree(lc);
	return ret;
}

static void linear_dtr(struct dm_target *ti)
{
	struct linear_c *lc = (struct linear_c *) ti->private;

	dm_put_device(ti, lc->dev);
	kfree(lc);
}

static sector_t linear_map_sector(struct dm_target *ti, sector_t bi_sector)
{
	struct linear_c *lc = ti->private;

	return lc->start + dm_target_offset(ti, bi_sector);
}

static void linear_map_bio(struct dm_target *ti, struct bio *bio)
{
	struct linear_c *lc = ti->private;

	bio_set_dev(bio, lc->dev->bdev);
	if (bio_sectors(bio) || bio_op(bio) == REQ_OP_ZONE_RESET)
		bio->bi_iter.bi_sector =
			linear_map_sector(ti, bio->bi_iter.bi_sector);
}

static int linear_map(struct dm_target *ti, struct bio *bio)
{
	linear_map_bio(ti, bio);

	return DM_MAPIO_REMAPPED;
}

static void linear_status(struct dm_target *ti, status_type_t type,
			  unsigned status_flags, char *result, unsigned maxlen)
{
	struct linear_c *lc = (struct linear_c *) ti->private;

	switch (type) {
	case STATUSTYPE_INFO:
		result[0] = '\0';
		break;

	case STATUSTYPE_TABLE:
		snprintf(result, maxlen, "%s %llu", lc->dev->name,
				(unsigned long long)lc->start);
		break;
	}
}

static int linear_prepare_ioctl(struct dm_target *ti, struct block_device **bdev)
{
	struct linear_c *lc = (struct linear_c *) ti->private;
	struct dm_dev *dev = lc->dev;

	*bdev = dev->bdev;

	/*
	 * Only pass ioctls through if the device sizes match exactly.
	 */
	if (lc->start ||
	    ti->len != i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT)
		return 1;
	return 0;
}

#ifdef CONFIG_BLK_DEV_ZONED
static int linear_report_zones(struct dm_target *ti, sector_t sector,
			       struct blk_zone *zones, unsigned int *nr_zones)
{
	struct linear_c *lc = (struct linear_c *) ti->private;
	int ret;

	/* Do report and remap it */
	ret = blkdev_report_zones(lc->dev->bdev, linear_map_sector(ti, sector),
				  zones, nr_zones);
	if (ret != 0)
		return ret;

	if (*nr_zones)
		dm_remap_zone_report(ti, lc->start, zones, nr_zones);
	return 0;
}
#endif

static int linear_iterate_devices(struct dm_target *ti,
				  iterate_devices_callout_fn fn, void *data)
{
	struct linear_c *lc = ti->private;

	return fn(ti, lc->dev, lc->start, ti->len, data);
}

#if IS_ENABLED(CONFIG_DAX_DRIVER)
static long linear_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,
		long nr_pages, void **kaddr, pfn_t *pfn)
{
	long ret;
	struct linear_c *lc = ti->private;
	struct block_device *bdev = lc->dev->bdev;
	struct dax_device *dax_dev = lc->dev->dax_dev;
	sector_t dev_sector, sector = pgoff * PAGE_SECTORS;

	dev_sector = linear_map_sector(ti, sector);
	ret = bdev_dax_pgoff(bdev, dev_sector, nr_pages * PAGE_SIZE, &pgoff);
	if (ret)
		return ret;
	return dax_direct_access(dax_dev, pgoff, nr_pages, kaddr, pfn);
}

static size_t linear_dax_copy_from_iter(struct dm_target *ti, pgoff_t pgoff,
		void *addr, size_t bytes, struct iov_iter *i)
{
	struct linear_c *lc = ti->private;
	struct block_device *bdev = lc->dev->bdev;
	struct dax_device *dax_dev = lc->dev->dax_dev;
	sector_t dev_sector, sector = pgoff * PAGE_SECTORS;

	dev_sector = linear_map_sector(ti, sector);
	if (bdev_dax_pgoff(bdev, dev_sector, ALIGN(bytes, PAGE_SIZE), &pgoff))
		return 0;
	return dax_copy_from_iter(dax_dev, pgoff, addr, bytes, i);
}

static size_t linear_dax_copy_to_iter(struct dm_target *ti, pgoff_t pgoff,
		void *addr, size_t bytes, struct iov_iter *i)
{
	struct linear_c *lc = ti->private;
	struct block_device *bdev = lc->dev->bdev;
	struct dax_device *dax_dev = lc->dev->dax_dev;
	sector_t dev_sector, sector = pgoff * PAGE_SECTORS;

	dev_sector = linear_map_sector(ti, sector);
	if (bdev_dax_pgoff(bdev, dev_sector, ALIGN(bytes, PAGE_SIZE), &pgoff))
		return 0;
	return dax_copy_to_iter(dax_dev, pgoff, addr, bytes, i);
}

#else
#define linear_dax_direct_access NULL
#define linear_dax_copy_from_iter NULL
#define linear_dax_copy_to_iter NULL
#endif

static struct target_type linear_target = {
	.name   = "linear",
	.version = {1, 4, 0},
#ifdef CONFIG_BLK_DEV_ZONED
	.features = DM_TARGET_PASSES_INTEGRITY | DM_TARGET_ZONED_HM,
	.report_zones = linear_report_zones,
#else
	.features = DM_TARGET_PASSES_INTEGRITY,
#endif
	.module = THIS_MODULE,
	.ctr    = linear_ctr,
	.dtr    = linear_dtr,
	.map    = linear_map,
	.status = linear_status,
	.prepare_ioctl = linear_prepare_ioctl,
	.iterate_devices = linear_iterate_devices,
	.direct_access = linear_dax_direct_access,
	.dax_copy_from_iter = linear_dax_copy_from_iter,
	.dax_copy_to_iter = linear_dax_copy_to_iter,
};

int __init dm_linear_init(void)
{
	int r = dm_register_target(&linear_target);

	if (r < 0)
		DMERR("register failed %d", r);

	return r;
}

void dm_linear_exit(void)
{
	dm_unregister_target(&linear_target);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Copyright (C) 2001-2003 Sistina Software (UK) Limited.
	3	*
	4	* This file is released under the GPL.
	5	*/
	6
	7	#include "dm.h"
1da177e4 LT	8	#include <linux/module.h>
	9	#include <linux/init.h>
	10	#include <linux/blkdev.h>
	11	#include <linux/bio.h>
817bf402	12	#include <linux/dax.h>
1da177e4	13	#include <linux/slab.h>
586e80e6	14	#include <linux/device-mapper.h>
1da177e4	15
72d94861 AK	16	#define DM_MSG_PREFIX "linear"
72d94861 AK	17
1da177e4 LT	18	/*
	19	* Linear: maps a linear range of a device.
	20	*/
	21	struct linear_c {
	22	struct dm_dev *dev;
	23	sector_t start;
	24	};
	25
	26	/*
	27	* Construct a linear mapping: <dev_path> <offset>
	28	*/
	29	static int linear_ctr(struct dm_target ti, unsigned int argc, char *argv)
	30	{
	31	struct linear_c *lc;
4ee218cd	32	unsigned long long tmp;
31998ef1	33	char dummy;
e80d1c80	34	int ret;
1da177e4 LT	35
1da177e4 LT	36	if (argc != 2) {
72d94861	37	ti->error = "Invalid argument count";
1da177e4 LT	38	return -EINVAL;
	39	}
	40
	41	lc = kmalloc(sizeof(*lc), GFP_KERNEL);
	42	if (lc == NULL) {
00272c85	43	ti->error = "Cannot allocate linear context";
1da177e4 LT	44	return -ENOMEM;
	45	}
	46
e80d1c80	47	ret = -EINVAL;
ef87bfc2	48	if (sscanf(argv[1], "%llu%c", &tmp, &dummy) != 1 \|\| tmp != (sector_t)tmp) {
00272c85	49	ti->error = "Invalid device sector";
1da177e4 LT	50	goto bad;
1da177e4 LT	51	}
4ee218cd	52	lc->start = tmp;
1da177e4	53
e80d1c80 VG	54	ret = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &lc->dev);
e80d1c80 VG	55	if (ret) {
00272c85	56	ti->error = "Device lookup failed";
1da177e4 LT	57	goto bad;
	58	}
	59
55a62eef AK	60	ti->num_flush_bios = 1;
55a62eef AK	61	ti->num_discard_bios = 1;
00716545	62	ti->num_secure_erase_bios = 1;
55a62eef	63	ti->num_write_same_bios = 1;
ac62d620	64	ti->num_write_zeroes_bios = 1;
1da177e4 LT	65	ti->private = lc;
	66	return 0;
	67
	68	bad:
	69	kfree(lc);
e80d1c80	70	return ret;
1da177e4 LT	71	}
	72
	73	static void linear_dtr(struct dm_target *ti)
	74	{
	75	struct linear_c lc = (struct linear_c ) ti->private;
	76
	77	dm_put_device(ti, lc->dev);
	78	kfree(lc);
	79	}
	80
7bc3447b	81	static sector_t linear_map_sector(struct dm_target *ti, sector_t bi_sector)
1da177e4	82	{
7bc3447b MB	83	struct linear_c *lc = ti->private;
7bc3447b MB	84
b441a262	85	return lc->start + dm_target_offset(ti, bi_sector);
7bc3447b MB	86	}
	87
	88	static void linear_map_bio(struct dm_target ti, struct bio bio)
	89	{
	90	struct linear_c *lc = ti->private;
1da177e4	91
74d46992	92	bio_set_dev(bio, lc->dev->bdev);
0be12c1c	93	if (bio_sectors(bio) \|\| bio_op(bio) == REQ_OP_ZONE_RESET)
4f024f37 KO	94	bio->bi_iter.bi_sector =
4f024f37 KO	95	linear_map_sector(ti, bio->bi_iter.bi_sector);
7bc3447b MB	96	}
7bc3447b MB	97
7de3ee57	98	static int linear_map(struct dm_target ti, struct bio bio)
7bc3447b MB	99	{
7bc3447b MB	100	linear_map_bio(ti, bio);
1da177e4	101
d2a7ad29	102	return DM_MAPIO_REMAPPED;
1da177e4 LT	103	}
1da177e4 LT	104
fd7c092e MP	105	static void linear_status(struct dm_target *ti, status_type_t type,
fd7c092e MP	106	unsigned status_flags, char *result, unsigned maxlen)
1da177e4 LT	107	{
	108	struct linear_c lc = (struct linear_c ) ti->private;
	109
	110	switch (type) {
	111	case STATUSTYPE_INFO:
	112	result[0] = '\0';
	113	break;
	114
	115	case STATUSTYPE_TABLE:
4ee218cd AM	116	snprintf(result, maxlen, "%s %llu", lc->dev->name,
4ee218cd AM	117	(unsigned long long)lc->start);
1da177e4 LT	118	break;
1da177e4 LT	119	}
1da177e4 LT	120	}
1da177e4 LT	121
5bd5e8d8	122	static int linear_prepare_ioctl(struct dm_target ti, struct block_device *bdev)
ab17ffa4 MB	123	{
ab17ffa4 MB	124	struct linear_c lc = (struct linear_c ) ti->private;
ec8013be	125	struct dm_dev *dev = lc->dev;
e56f81e0 CH	126
e56f81e0 CH	127	*bdev = dev->bdev;
ec8013be PB	128
	129	/*
	130	* Only pass ioctls through if the device sizes match exactly.
	131	*/
	132	if (lc->start \|\|
	133	ti->len != i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT)
e56f81e0 CH	134	return 1;
e56f81e0 CH	135	return 0;
ab17ffa4 MB	136	}
ab17ffa4 MB	137
e76239a3 CH	138	#ifdef CONFIG_BLK_DEV_ZONED
e76239a3 CH	139	static int linear_report_zones(struct dm_target *ti, sector_t sector,
bd976e52	140	struct blk_zone zones, unsigned int nr_zones)
e76239a3 CH	141	{
	142	struct linear_c lc = (struct linear_c ) ti->private;
	143	int ret;
	144
	145	/* Do report and remap it */
	146	ret = blkdev_report_zones(lc->dev->bdev, linear_map_sector(ti, sector),
bd976e52	147	zones, nr_zones);
e76239a3 CH	148	if (ret != 0)
	149	return ret;
	150
	151	if (*nr_zones)
	152	dm_remap_zone_report(ti, lc->start, zones, nr_zones);
	153	return 0;
	154	}
	155	#endif
	156
af4874e0 MS	157	static int linear_iterate_devices(struct dm_target *ti,
	158	iterate_devices_callout_fn fn, void *data)
	159	{
	160	struct linear_c *lc = ti->private;
	161
5dea271b	162	return fn(ti, lc->dev, lc->start, ti->len, data);
af4874e0 MS	163	}
af4874e0 MS	164
976431b0	165	#if IS_ENABLED(CONFIG_DAX_DRIVER)
817bf402 DW	166	static long linear_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,
817bf402 DW	167	long nr_pages, void *kaddr, pfn_t pfn)
84b22f83	168	{
817bf402	169	long ret;
84b22f83 TK	170	struct linear_c *lc = ti->private;
84b22f83 TK	171	struct block_device *bdev = lc->dev->bdev;
817bf402 DW	172	struct dax_device *dax_dev = lc->dev->dax_dev;
	173	sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
	174
	175	dev_sector = linear_map_sector(ti, sector);
	176	ret = bdev_dax_pgoff(bdev, dev_sector, nr_pages * PAGE_SIZE, &pgoff);
	177	if (ret)
	178	return ret;
	179	return dax_direct_access(dax_dev, pgoff, nr_pages, kaddr, pfn);
84b22f83 TK	180	}
84b22f83 TK	181
7e026c8c DW	182	static size_t linear_dax_copy_from_iter(struct dm_target *ti, pgoff_t pgoff,
	183	void addr, size_t bytes, struct iov_iter i)
	184	{
	185	struct linear_c *lc = ti->private;
	186	struct block_device *bdev = lc->dev->bdev;
	187	struct dax_device *dax_dev = lc->dev->dax_dev;
	188	sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
	189
	190	dev_sector = linear_map_sector(ti, sector);
	191	if (bdev_dax_pgoff(bdev, dev_sector, ALIGN(bytes, PAGE_SIZE), &pgoff))
	192	return 0;
	193	return dax_copy_from_iter(dax_dev, pgoff, addr, bytes, i);
	194	}
	195
b3a9a0c3 DW	196	static size_t linear_dax_copy_to_iter(struct dm_target *ti, pgoff_t pgoff,
	197	void addr, size_t bytes, struct iov_iter i)
	198	{
	199	struct linear_c *lc = ti->private;
	200	struct block_device *bdev = lc->dev->bdev;
	201	struct dax_device *dax_dev = lc->dev->dax_dev;
	202	sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
	203
	204	dev_sector = linear_map_sector(ti, sector);
	205	if (bdev_dax_pgoff(bdev, dev_sector, ALIGN(bytes, PAGE_SIZE), &pgoff))
	206	return 0;
	207	return dax_copy_to_iter(dax_dev, pgoff, addr, bytes, i);
	208	}
	209
976431b0 DW	210	#else
	211	#define linear_dax_direct_access NULL
	212	#define linear_dax_copy_from_iter NULL
b3a9a0c3	213	#define linear_dax_copy_to_iter NULL
976431b0 DW	214	#endif
976431b0 DW	215
1da177e4 LT	216	static struct target_type linear_target = {
1da177e4 LT	217	.name = "linear",
0be12c1c	218	.version = {1, 4, 0},
118aa47c	219	#ifdef CONFIG_BLK_DEV_ZONED
0be12c1c	220	.features = DM_TARGET_PASSES_INTEGRITY \| DM_TARGET_ZONED_HM,
e76239a3	221	.report_zones = linear_report_zones,
beb9caac MS	222	#else
	223	.features = DM_TARGET_PASSES_INTEGRITY,
	224	#endif
1da177e4 LT	225	.module = THIS_MODULE,
	226	.ctr = linear_ctr,
	227	.dtr = linear_dtr,
	228	.map = linear_map,
	229	.status = linear_status,
e56f81e0	230	.prepare_ioctl = linear_prepare_ioctl,
af4874e0	231	.iterate_devices = linear_iterate_devices,
817bf402	232	.direct_access = linear_dax_direct_access,
7e026c8c	233	.dax_copy_from_iter = linear_dax_copy_from_iter,
b3a9a0c3	234	.dax_copy_to_iter = linear_dax_copy_to_iter,
1da177e4 LT	235	};
	236
	237	int __init dm_linear_init(void)
	238	{
	239	int r = dm_register_target(&linear_target);
	240
	241	if (r < 0)
72d94861	242	DMERR("register failed %d", r);
1da177e4 LT	243
	244	return r;
	245	}
	246
	247	void dm_linear_exit(void)
	248	{
10d3bd09	249	dm_unregister_target(&linear_target);
1da177e4	250	}