[GitHub/moto-9609/android_kernel_motorola_exynos9610.git] / block / blk-lib.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Functions related to generic helpers functions
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/bio.h>
#include <linux/blkdev.h>
#include <linux/scatterlist.h>

#include "blk.h"

static struct bio *next_bio(struct bio *bio, unsigned int nr_pages,
		gfp_t gfp)
{
	struct bio *new = bio_alloc(gfp, nr_pages);

	if (bio) {
		bio_chain(bio, new);
		submit_bio(bio);
	}

	return new;
}

int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
		sector_t nr_sects, gfp_t gfp_mask, int flags,
		struct bio **biop)
{
	struct request_queue *q = bdev_get_queue(bdev);
	struct bio *bio = *biop;
	unsigned int granularity;
	unsigned int op;
	int alignment;
	sector_t bs_mask;

	if (!q)
		return -ENXIO;

	if (flags & BLKDEV_DISCARD_SECURE) {
		if (!blk_queue_secure_erase(q))
			return -EOPNOTSUPP;
		op = REQ_OP_SECURE_ERASE;
	} else {
		if (!blk_queue_discard(q))
			return -EOPNOTSUPP;
		op = REQ_OP_DISCARD;
	}

	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
	if ((sector | nr_sects) & bs_mask)
		return -EINVAL;

	/* Zero-sector (unknown) and one-sector granularities are the same.  */
	granularity = max(q->limits.discard_granularity >> 9, 1U);
	alignment = (bdev_discard_alignment(bdev) >> 9) % granularity;

	while (nr_sects) {
		unsigned int req_sects;
		sector_t end_sect, tmp;

		/*
		 * Issue in chunks of the user defined max discard setting,
		 * ensuring that bi_size doesn't overflow
		 */
		req_sects = min_t(sector_t, nr_sects,
					q->limits.max_discard_sectors);
		if (!req_sects)
			goto fail;
		if (req_sects > UINT_MAX >> 9)
			req_sects = UINT_MAX >> 9;

		/*
		 * If splitting a request, and the next starting sector would be
		 * misaligned, stop the discard at the previous aligned sector.
		 */
		end_sect = sector + req_sects;
		tmp = end_sect;
		if (req_sects < nr_sects &&
		    sector_div(tmp, granularity) != alignment) {
			end_sect = end_sect - alignment;
			sector_div(end_sect, granularity);
			end_sect = end_sect * granularity + alignment;
			req_sects = end_sect - sector;
		}

		bio = next_bio(bio, 0, gfp_mask);
		bio->bi_iter.bi_sector = sector;
		bio_set_dev(bio, bdev);
		bio_set_op_attrs(bio, op, 0);

		bio->bi_iter.bi_size = req_sects << 9;
		nr_sects -= req_sects;
		sector = end_sect;

		/*
		 * We can loop for a long time in here, if someone does
		 * full device discards (like mkfs). Be nice and allow
		 * us to schedule out to avoid softlocking if preempt
		 * is disabled.
		 */
		cond_resched();
	}

	*biop = bio;
	return 0;

fail:
	if (bio) {
		submit_bio_wait(bio);
		bio_put(bio);
	}
	*biop = NULL;
	return -EOPNOTSUPP;
}
EXPORT_SYMBOL(__blkdev_issue_discard);

/**
 * blkdev_issue_discard - queue a discard
 * @bdev:	blockdev to issue discard for
 * @sector:	start sector
 * @nr_sects:	number of sectors to discard
 * @gfp_mask:	memory allocation flags (for bio_alloc)
 * @flags:	BLKDEV_DISCARD_* flags to control behaviour
 *
 * Description:
 *    Issue a discard request for the sectors in question.
 */
int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
		sector_t nr_sects, gfp_t gfp_mask, unsigned long flags)
{
	struct bio *bio = NULL;
	struct blk_plug plug;
	int ret;

	blk_start_plug(&plug);
	ret = __blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask, flags,
			&bio);
	if (!ret && bio) {
		ret = submit_bio_wait(bio);
		if (ret == -EOPNOTSUPP)
			ret = 0;
		bio_put(bio);
	}
	blk_finish_plug(&plug);

	return ret;
}
EXPORT_SYMBOL(blkdev_issue_discard);

/**
 * __blkdev_issue_write_same - generate number of bios with same page
 * @bdev:	target blockdev
 * @sector:	start sector
 * @nr_sects:	number of sectors to write
 * @gfp_mask:	memory allocation flags (for bio_alloc)
 * @page:	page containing data to write
 * @biop:	pointer to anchor bio
 *
 * Description:
 *  Generate and issue number of bios(REQ_OP_WRITE_SAME) with same page.
 */
static int __blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
		sector_t nr_sects, gfp_t gfp_mask, struct page *page,
		struct bio **biop)
{
	struct request_queue *q = bdev_get_queue(bdev);
	unsigned int max_write_same_sectors;
	struct bio *bio = *biop;
	sector_t bs_mask;

	if (!q)
		return -ENXIO;

	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
	if ((sector | nr_sects) & bs_mask)
		return -EINVAL;

	if (!bdev_write_same(bdev))
		return -EOPNOTSUPP;

	/* Ensure that max_write_same_sectors doesn't overflow bi_size */
	max_write_same_sectors = UINT_MAX >> 9;

	while (nr_sects) {
		bio = next_bio(bio, 1, gfp_mask);
		bio->bi_iter.bi_sector = sector;
		bio_set_dev(bio, bdev);
		bio->bi_vcnt = 1;
		bio->bi_io_vec->bv_page = page;
		bio->bi_io_vec->bv_offset = 0;
		bio->bi_io_vec->bv_len = bdev_logical_block_size(bdev);
		bio_set_op_attrs(bio, REQ_OP_WRITE_SAME, 0);

		if (nr_sects > max_write_same_sectors) {
			bio->bi_iter.bi_size = max_write_same_sectors << 9;
			nr_sects -= max_write_same_sectors;
			sector += max_write_same_sectors;
		} else {
			bio->bi_iter.bi_size = nr_sects << 9;
			nr_sects = 0;
		}
		cond_resched();
	}

	*biop = bio;
	return 0;
}

/**
 * blkdev_issue_write_same - queue a write same operation
 * @bdev:	target blockdev
 * @sector:	start sector
 * @nr_sects:	number of sectors to write
 * @gfp_mask:	memory allocation flags (for bio_alloc)
 * @page:	page containing data
 *
 * Description:
 *    Issue a write same request for the sectors in question.
 */
int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
				sector_t nr_sects, gfp_t gfp_mask,
				struct page *page)
{
	struct bio *bio = NULL;
	struct blk_plug plug;
	int ret;

	blk_start_plug(&plug);
	ret = __blkdev_issue_write_same(bdev, sector, nr_sects, gfp_mask, page,
			&bio);
	if (ret == 0 && bio) {
		ret = submit_bio_wait(bio);
		bio_put(bio);
	}
	blk_finish_plug(&plug);
	return ret;
}
EXPORT_SYMBOL(blkdev_issue_write_same);

static int __blkdev_issue_write_zeroes(struct block_device *bdev,
		sector_t sector, sector_t nr_sects, gfp_t gfp_mask,
		struct bio **biop, unsigned flags)
{
	struct bio *bio = *biop;
	unsigned int max_write_zeroes_sectors;
	struct request_queue *q = bdev_get_queue(bdev);

	if (!q)
		return -ENXIO;

	/* Ensure that max_write_zeroes_sectors doesn't overflow bi_size */
	max_write_zeroes_sectors = bdev_write_zeroes_sectors(bdev);

	if (max_write_zeroes_sectors == 0)
		return -EOPNOTSUPP;

	while (nr_sects) {
		bio = next_bio(bio, 0, gfp_mask);
		bio->bi_iter.bi_sector = sector;
		bio_set_dev(bio, bdev);
		bio->bi_opf = REQ_OP_WRITE_ZEROES;
		if (flags & BLKDEV_ZERO_NOUNMAP)
			bio->bi_opf |= REQ_NOUNMAP;

		if (nr_sects > max_write_zeroes_sectors) {
			bio->bi_iter.bi_size = max_write_zeroes_sectors << 9;
			nr_sects -= max_write_zeroes_sectors;
			sector += max_write_zeroes_sectors;
		} else {
			bio->bi_iter.bi_size = nr_sects << 9;
			nr_sects = 0;
		}
		cond_resched();
	}

	*biop = bio;
	return 0;
}

/*
 * Convert a number of 512B sectors to a number of pages.
 * The result is limited to a number of pages that can fit into a BIO.
 * Also make sure that the result is always at least 1 (page) for the cases
 * where nr_sects is lower than the number of sectors in a page.
 */
static unsigned int __blkdev_sectors_to_bio_pages(sector_t nr_sects)
{
	sector_t pages = DIV_ROUND_UP_SECTOR_T(nr_sects, PAGE_SIZE / 512);

	return min(pages, (sector_t)BIO_MAX_PAGES);
}

static int __blkdev_issue_zero_pages(struct block_device *bdev,
		sector_t sector, sector_t nr_sects, gfp_t gfp_mask,
		struct bio **biop)
{
	struct request_queue *q = bdev_get_queue(bdev);
	struct bio *bio = *biop;
	int bi_size = 0;
	unsigned int sz;

	if (!q)
		return -ENXIO;

	while (nr_sects != 0) {
		bio = next_bio(bio, __blkdev_sectors_to_bio_pages(nr_sects),
			       gfp_mask);
		bio->bi_iter.bi_sector = sector;
		bio_set_dev(bio, bdev);
		bio_set_op_attrs(bio, REQ_OP_WRITE, 0);

		while (nr_sects != 0) {
			sz = min((sector_t) PAGE_SIZE, nr_sects << 9);
			bi_size = bio_add_page(bio, ZERO_PAGE(0), sz, 0);
			nr_sects -= bi_size >> 9;
			sector += bi_size >> 9;
			if (bi_size < sz)
				break;
		}
		cond_resched();
	}

	*biop = bio;
	return 0;
}

/**
 * __blkdev_issue_zeroout - generate number of zero filed write bios
 * @bdev:	blockdev to issue
 * @sector:	start sector
 * @nr_sects:	number of sectors to write
 * @gfp_mask:	memory allocation flags (for bio_alloc)
 * @biop:	pointer to anchor bio
 * @flags:	controls detailed behavior
 *
 * Description:
 *  Zero-fill a block range, either using hardware offload or by explicitly
 *  writing zeroes to the device.
 *
 *  If a device is using logical block provisioning, the underlying space will
 *  not be released if %flags contains BLKDEV_ZERO_NOUNMAP.
 *
 *  If %flags contains BLKDEV_ZERO_NOFALLBACK, the function will return
 *  -EOPNOTSUPP if no explicit hardware offload for zeroing is provided.
 */
int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
		sector_t nr_sects, gfp_t gfp_mask, struct bio **biop,
		unsigned flags)
{
	int ret;
	sector_t bs_mask;

	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
	if ((sector | nr_sects) & bs_mask)
		return -EINVAL;

	ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects, gfp_mask,
			biop, flags);
	if (ret != -EOPNOTSUPP || (flags & BLKDEV_ZERO_NOFALLBACK))
		return ret;

	return __blkdev_issue_zero_pages(bdev, sector, nr_sects, gfp_mask,
					 biop);
}
EXPORT_SYMBOL(__blkdev_issue_zeroout);

/**
 * blkdev_issue_zeroout - zero-fill a block range
 * @bdev:	blockdev to write
 * @sector:	start sector
 * @nr_sects:	number of sectors to write
 * @gfp_mask:	memory allocation flags (for bio_alloc)
 * @flags:	controls detailed behavior
 *
 * Description:
 *  Zero-fill a block range, either using hardware offload or by explicitly
 *  writing zeroes to the device.  See __blkdev_issue_zeroout() for the
 *  valid values for %flags.
 */
int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
		sector_t nr_sects, gfp_t gfp_mask, unsigned flags)
{
	int ret = 0;
	sector_t bs_mask;
	struct bio *bio;
	struct blk_plug plug;
	bool try_write_zeroes = !!bdev_write_zeroes_sectors(bdev);

	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
	if ((sector | nr_sects) & bs_mask)
		return -EINVAL;

retry:
	bio = NULL;
	blk_start_plug(&plug);
	if (try_write_zeroes) {
		ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects,
						  gfp_mask, &bio, flags);
	} else if (!(flags & BLKDEV_ZERO_NOFALLBACK)) {
		ret = __blkdev_issue_zero_pages(bdev, sector, nr_sects,
						gfp_mask, &bio);
	} else {
		/* No zeroing offload support */
		ret = -EOPNOTSUPP;
	}
	if (ret == 0 && bio) {
		ret = submit_bio_wait(bio);
		bio_put(bio);
	}
	blk_finish_plug(&plug);
	if (ret && try_write_zeroes) {
		if (!(flags & BLKDEV_ZERO_NOFALLBACK)) {
			try_write_zeroes = false;
			goto retry;
		}
		if (!bdev_write_zeroes_sectors(bdev)) {
			/*
			 * Zeroing offload support was indicated, but the
			 * device reported ILLEGAL REQUEST (for some devices
			 * there is no non-destructive way to verify whether
			 * WRITE ZEROES is actually supported).
			 */
			ret = -EOPNOTSUPP;
		}
	}

	return ret;
}
EXPORT_SYMBOL(blkdev_issue_zeroout);
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
f31e7e40 DM	2	/*
	3	* Functions related to generic helpers functions
	4	*/
	5	#include <linux/kernel.h>
	6	#include <linux/module.h>
	7	#include <linux/bio.h>
	8	#include <linux/blkdev.h>
	9	#include <linux/scatterlist.h>
	10
	11	#include "blk.h"
	12
4e49ea4a	13	static struct bio next_bio(struct bio bio, unsigned int nr_pages,
9082e87b	14	gfp_t gfp)
f31e7e40	15	{
9082e87b CH	16	struct bio *new = bio_alloc(gfp, nr_pages);
	17
	18	if (bio) {
	19	bio_chain(bio, new);
4e49ea4a	20	submit_bio(bio);
9082e87b	21	}
5dba3089	22
9082e87b	23	return new;
f31e7e40 DM	24	}
f31e7e40 DM	25
38f25255	26	int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
288dab8a	27	sector_t nr_sects, gfp_t gfp_mask, int flags,
469e3216	28	struct bio **biop)
f31e7e40	29	{
f31e7e40	30	struct request_queue *q = bdev_get_queue(bdev);
38f25255	31	struct bio bio = biop;
a22c4d7e	32	unsigned int granularity;
ef295ecf	33	unsigned int op;
a22c4d7e	34	int alignment;
28b2be20	35	sector_t bs_mask;
f31e7e40 DM	36
	37	if (!q)
	38	return -ENXIO;
288dab8a CH	39
	40	if (flags & BLKDEV_DISCARD_SECURE) {
	41	if (!blk_queue_secure_erase(q))
	42	return -EOPNOTSUPP;
	43	op = REQ_OP_SECURE_ERASE;
	44	} else {
	45	if (!blk_queue_discard(q))
	46	return -EOPNOTSUPP;
	47	op = REQ_OP_DISCARD;
	48	}
f31e7e40	49
28b2be20 DW	50	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
	51	if ((sector \| nr_sects) & bs_mask)
	52	return -EINVAL;
	53
a22c4d7e ML	54	/* Zero-sector (unknown) and one-sector granularities are the same. */
	55	granularity = max(q->limits.discard_granularity >> 9, 1U);
	56	alignment = (bdev_discard_alignment(bdev) >> 9) % granularity;
	57
5dba3089	58	while (nr_sects) {
c6e66634	59	unsigned int req_sects;
a22c4d7e	60	sector_t end_sect, tmp;
c6e66634	61
1e9290ca JA	62	/*
	63	* Issue in chunks of the user defined max discard setting,
	64	* ensuring that bi_size doesn't overflow
	65	*/
	66	req_sects = min_t(sector_t, nr_sects,
	67	q->limits.max_discard_sectors);
07eae146 MP	68	if (!req_sects)
07eae146 MP	69	goto fail;
1e9290ca JA	70	if (req_sects > UINT_MAX >> 9)
1e9290ca JA	71	req_sects = UINT_MAX >> 9;
a22c4d7e	72
1e9290ca	73	/*
a22c4d7e ML	74	* If splitting a request, and the next starting sector would be
	75	* misaligned, stop the discard at the previous aligned sector.
	76	*/
c6e66634	77	end_sect = sector + req_sects;
a22c4d7e ML	78	tmp = end_sect;
	79	if (req_sects < nr_sects &&
	80	sector_div(tmp, granularity) != alignment) {
	81	end_sect = end_sect - alignment;
	82	sector_div(end_sect, granularity);
	83	end_sect = end_sect * granularity + alignment;
	84	req_sects = end_sect - sector;
	85	}
c6e66634	86
f9d03f96	87	bio = next_bio(bio, 0, gfp_mask);
4f024f37	88	bio->bi_iter.bi_sector = sector;
74d46992	89	bio_set_dev(bio, bdev);
288dab8a	90	bio_set_op_attrs(bio, op, 0);
f31e7e40	91
4f024f37	92	bio->bi_iter.bi_size = req_sects << 9;
c6e66634 PB	93	nr_sects -= req_sects;
c6e66634 PB	94	sector = end_sect;
f31e7e40	95
c8123f8c JA	96	/*
	97	* We can loop for a long time in here, if someone does
	98	* full device discards (like mkfs). Be nice and allow
	99	* us to schedule out to avoid softlocking if preempt
	100	* is disabled.
	101	*/
	102	cond_resched();
5dba3089	103	}
38f25255 CH	104
	105	*biop = bio;
	106	return 0;
07eae146 MP	107
	108	fail:
	109	if (bio) {
	110	submit_bio_wait(bio);
	111	bio_put(bio);
	112	}
	113	*biop = NULL;
	114	return -EOPNOTSUPP;
38f25255 CH	115	}
	116	EXPORT_SYMBOL(__blkdev_issue_discard);
	117
	118	/**
	119	* blkdev_issue_discard - queue a discard
	120	* @bdev: blockdev to issue discard for
	121	* @sector: start sector
	122	* @nr_sects: number of sectors to discard
	123	* @gfp_mask: memory allocation flags (for bio_alloc)
e554911c	124	* @flags: BLKDEV_DISCARD_* flags to control behaviour
38f25255 CH	125	*
	126	* Description:
	127	* Issue a discard request for the sectors in question.
	128	*/
	129	int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
	130	sector_t nr_sects, gfp_t gfp_mask, unsigned long flags)
	131	{
38f25255 CH	132	struct bio *bio = NULL;
	133	struct blk_plug plug;
	134	int ret;
	135
38f25255	136	blk_start_plug(&plug);
288dab8a	137	ret = __blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask, flags,
38f25255	138	&bio);
bbd848e0	139	if (!ret && bio) {
4e49ea4a	140	ret = submit_bio_wait(bio);
48920ff2	141	if (ret == -EOPNOTSUPP)
bbd848e0	142	ret = 0;
05bd92dd	143	bio_put(bio);
bbd848e0	144	}
0cfbcafc	145	blk_finish_plug(&plug);
f31e7e40	146
bbd848e0	147	return ret;
f31e7e40 DM	148	}
f31e7e40 DM	149	EXPORT_SYMBOL(blkdev_issue_discard);
3f14d792	150
4363ac7c	151	/**
e73c23ff	152	* __blkdev_issue_write_same - generate number of bios with same page
4363ac7c MP	153	* @bdev: target blockdev
	154	* @sector: start sector
	155	* @nr_sects: number of sectors to write
	156	* @gfp_mask: memory allocation flags (for bio_alloc)
	157	* @page: page containing data to write
e73c23ff	158	* @biop: pointer to anchor bio
4363ac7c MP	159	*
4363ac7c MP	160	* Description:
e73c23ff	161	* Generate and issue number of bios(REQ_OP_WRITE_SAME) with same page.
4363ac7c	162	*/
e73c23ff CK	163	static int __blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
	164	sector_t nr_sects, gfp_t gfp_mask, struct page *page,
	165	struct bio **biop)
4363ac7c	166	{
4363ac7c MP	167	struct request_queue *q = bdev_get_queue(bdev);
4363ac7c MP	168	unsigned int max_write_same_sectors;
e73c23ff	169	struct bio bio = biop;
28b2be20	170	sector_t bs_mask;
4363ac7c MP	171
	172	if (!q)
	173	return -ENXIO;
	174
28b2be20 DW	175	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
	176	if ((sector \| nr_sects) & bs_mask)
	177	return -EINVAL;
	178
e73c23ff CK	179	if (!bdev_write_same(bdev))
	180	return -EOPNOTSUPP;
	181
b49a0871 ML	182	/* Ensure that max_write_same_sectors doesn't overflow bi_size */
b49a0871 ML	183	max_write_same_sectors = UINT_MAX >> 9;
4363ac7c	184
4363ac7c	185	while (nr_sects) {
4e49ea4a	186	bio = next_bio(bio, 1, gfp_mask);
4f024f37	187	bio->bi_iter.bi_sector = sector;
74d46992	188	bio_set_dev(bio, bdev);
4363ac7c MP	189	bio->bi_vcnt = 1;
	190	bio->bi_io_vec->bv_page = page;
	191	bio->bi_io_vec->bv_offset = 0;
	192	bio->bi_io_vec->bv_len = bdev_logical_block_size(bdev);
95fe6c1a	193	bio_set_op_attrs(bio, REQ_OP_WRITE_SAME, 0);
4363ac7c MP	194
4363ac7c MP	195	if (nr_sects > max_write_same_sectors) {
4f024f37	196	bio->bi_iter.bi_size = max_write_same_sectors << 9;
4363ac7c MP	197	nr_sects -= max_write_same_sectors;
	198	sector += max_write_same_sectors;
	199	} else {
4f024f37	200	bio->bi_iter.bi_size = nr_sects << 9;
4363ac7c MP	201	nr_sects = 0;
4363ac7c MP	202	}
e73c23ff	203	cond_resched();
4363ac7c MP	204	}
4363ac7c MP	205
e73c23ff CK	206	*biop = bio;
	207	return 0;
	208	}
	209
	210	/**
	211	* blkdev_issue_write_same - queue a write same operation
	212	* @bdev: target blockdev
	213	* @sector: start sector
	214	* @nr_sects: number of sectors to write
	215	* @gfp_mask: memory allocation flags (for bio_alloc)
	216	* @page: page containing data
	217	*
	218	* Description:
	219	* Issue a write same request for the sectors in question.
	220	*/
	221	int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
	222	sector_t nr_sects, gfp_t gfp_mask,
	223	struct page *page)
	224	{
	225	struct bio *bio = NULL;
	226	struct blk_plug plug;
	227	int ret;
	228
	229	blk_start_plug(&plug);
	230	ret = __blkdev_issue_write_same(bdev, sector, nr_sects, gfp_mask, page,
	231	&bio);
	232	if (ret == 0 && bio) {
4e49ea4a	233	ret = submit_bio_wait(bio);
05bd92dd ST	234	bio_put(bio);
05bd92dd ST	235	}
e73c23ff	236	blk_finish_plug(&plug);
3f40bf2c	237	return ret;
4363ac7c MP	238	}
	239	EXPORT_SYMBOL(blkdev_issue_write_same);
	240
a6f0788e CK	241	static int __blkdev_issue_write_zeroes(struct block_device *bdev,
a6f0788e CK	242	sector_t sector, sector_t nr_sects, gfp_t gfp_mask,
d928be9f	243	struct bio **biop, unsigned flags)
a6f0788e CK	244	{
	245	struct bio bio = biop;
	246	unsigned int max_write_zeroes_sectors;
	247	struct request_queue *q = bdev_get_queue(bdev);
	248
	249	if (!q)
	250	return -ENXIO;
	251
	252	/* Ensure that max_write_zeroes_sectors doesn't overflow bi_size */
	253	max_write_zeroes_sectors = bdev_write_zeroes_sectors(bdev);
	254
	255	if (max_write_zeroes_sectors == 0)
	256	return -EOPNOTSUPP;
	257
	258	while (nr_sects) {
	259	bio = next_bio(bio, 0, gfp_mask);
	260	bio->bi_iter.bi_sector = sector;
74d46992	261	bio_set_dev(bio, bdev);
d928be9f CH	262	bio->bi_opf = REQ_OP_WRITE_ZEROES;
	263	if (flags & BLKDEV_ZERO_NOUNMAP)
	264	bio->bi_opf \|= REQ_NOUNMAP;
a6f0788e CK	265
	266	if (nr_sects > max_write_zeroes_sectors) {
	267	bio->bi_iter.bi_size = max_write_zeroes_sectors << 9;
	268	nr_sects -= max_write_zeroes_sectors;
	269	sector += max_write_zeroes_sectors;
	270	} else {
	271	bio->bi_iter.bi_size = nr_sects << 9;
	272	nr_sects = 0;
	273	}
	274	cond_resched();
	275	}
	276
	277	*biop = bio;
	278	return 0;
	279	}
	280
615d22a5 DLM	281	/*
	282	* Convert a number of 512B sectors to a number of pages.
	283	* The result is limited to a number of pages that can fit into a BIO.
	284	* Also make sure that the result is always at least 1 (page) for the cases
	285	* where nr_sects is lower than the number of sectors in a page.
	286	*/
	287	static unsigned int __blkdev_sectors_to_bio_pages(sector_t nr_sects)
	288	{
09c2c359	289	sector_t pages = DIV_ROUND_UP_SECTOR_T(nr_sects, PAGE_SIZE / 512);
615d22a5	290
09c2c359	291	return min(pages, (sector_t)BIO_MAX_PAGES);
615d22a5 DLM	292	}
615d22a5 DLM	293
3e3f1310 ID	294	static int __blkdev_issue_zero_pages(struct block_device *bdev,
	295	sector_t sector, sector_t nr_sects, gfp_t gfp_mask,
	296	struct bio **biop)
	297	{
	298	struct request_queue *q = bdev_get_queue(bdev);
	299	struct bio bio = biop;
	300	int bi_size = 0;
	301	unsigned int sz;
	302
	303	if (!q)
	304	return -ENXIO;
	305
	306	while (nr_sects != 0) {
	307	bio = next_bio(bio, __blkdev_sectors_to_bio_pages(nr_sects),
	308	gfp_mask);
	309	bio->bi_iter.bi_sector = sector;
	310	bio_set_dev(bio, bdev);
	311	bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
	312
	313	while (nr_sects != 0) {
	314	sz = min((sector_t) PAGE_SIZE, nr_sects << 9);
	315	bi_size = bio_add_page(bio, ZERO_PAGE(0), sz, 0);
	316	nr_sects -= bi_size >> 9;
	317	sector += bi_size >> 9;
	318	if (bi_size < sz)
	319	break;
	320	}
	321	cond_resched();
	322	}
	323
	324	*biop = bio;
	325	return 0;
	326	}
	327
3f14d792	328	/**
e73c23ff	329	* __blkdev_issue_zeroout - generate number of zero filed write bios
3f14d792 DM	330	* @bdev: blockdev to issue
	331	* @sector: start sector
	332	* @nr_sects: number of sectors to write
	333	* @gfp_mask: memory allocation flags (for bio_alloc)
e73c23ff	334	* @biop: pointer to anchor bio
ee472d83	335	* @flags: controls detailed behavior
3f14d792 DM	336	*
3f14d792 DM	337	* Description:
ee472d83 CH	338	* Zero-fill a block range, either using hardware offload or by explicitly
	339	* writing zeroes to the device.
	340	*
	341	* If a device is using logical block provisioning, the underlying space will
	342	* not be released if %flags contains BLKDEV_ZERO_NOUNMAP.
cb365b96 CH	343	*
	344	* If %flags contains BLKDEV_ZERO_NOFALLBACK, the function will return
	345	* -EOPNOTSUPP if no explicit hardware offload for zeroing is provided.
3f14d792	346	*/
e73c23ff CK	347	int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
e73c23ff CK	348	sector_t nr_sects, gfp_t gfp_mask, struct bio **biop,
ee472d83	349	unsigned flags)
3f14d792	350	{
18edc8ea	351	int ret;
28b2be20 DW	352	sector_t bs_mask;
	353
	354	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
	355	if ((sector \| nr_sects) & bs_mask)
	356	return -EINVAL;
3f14d792	357
a6f0788e	358	ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects, gfp_mask,
d928be9f	359	biop, flags);
cb365b96	360	if (ret != -EOPNOTSUPP \|\| (flags & BLKDEV_ZERO_NOFALLBACK))
3e3f1310	361	return ret;
3f14d792	362
3e3f1310 ID	363	return __blkdev_issue_zero_pages(bdev, sector, nr_sects, gfp_mask,
3e3f1310 ID	364	biop);
3f14d792	365	}
e73c23ff	366	EXPORT_SYMBOL(__blkdev_issue_zeroout);
579e8f3c MP	367
	368	/**
	369	* blkdev_issue_zeroout - zero-fill a block range
	370	* @bdev: blockdev to write
	371	* @sector: start sector
	372	* @nr_sects: number of sectors to write
	373	* @gfp_mask: memory allocation flags (for bio_alloc)
ee472d83	374	* @flags: controls detailed behavior
579e8f3c MP	375	*
579e8f3c MP	376	* Description:
ee472d83 CH	377	* Zero-fill a block range, either using hardware offload or by explicitly
	378	* writing zeroes to the device. See __blkdev_issue_zeroout() for the
	379	* valid values for %flags.
579e8f3c	380	*/
579e8f3c	381	int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
ee472d83	382	sector_t nr_sects, gfp_t gfp_mask, unsigned flags)
579e8f3c	383	{
c894755d ID	384	int ret = 0;
	385	sector_t bs_mask;
	386	struct bio *bio;
e73c23ff	387	struct blk_plug plug;
c894755d	388	bool try_write_zeroes = !!bdev_write_zeroes_sectors(bdev);
d93ba7a5	389
c894755d ID	390	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
	391	if ((sector \| nr_sects) & bs_mask)
	392	return -EINVAL;
	393
	394	retry:
	395	bio = NULL;
e73c23ff	396	blk_start_plug(&plug);
c894755d ID	397	if (try_write_zeroes) {
	398	ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects,
	399	gfp_mask, &bio, flags);
	400	} else if (!(flags & BLKDEV_ZERO_NOFALLBACK)) {
	401	ret = __blkdev_issue_zero_pages(bdev, sector, nr_sects,
	402	gfp_mask, &bio);
	403	} else {
	404	/* No zeroing offload support */
	405	ret = -EOPNOTSUPP;
	406	}
e73c23ff CK	407	if (ret == 0 && bio) {
	408	ret = submit_bio_wait(bio);
	409	bio_put(bio);
	410	}
	411	blk_finish_plug(&plug);
c894755d ID	412	if (ret && try_write_zeroes) {
	413	if (!(flags & BLKDEV_ZERO_NOFALLBACK)) {
	414	try_write_zeroes = false;
	415	goto retry;
	416	}
	417	if (!bdev_write_zeroes_sectors(bdev)) {
	418	/*
	419	* Zeroing offload support was indicated, but the
	420	* device reported ILLEGAL REQUEST (for some devices
	421	* there is no non-destructive way to verify whether
	422	* WRITE ZEROES is actually supported).
	423	*/
	424	ret = -EOPNOTSUPP;
	425	}
	426	}
579e8f3c	427
e73c23ff	428	return ret;
579e8f3c	429	}
3f14d792	430	EXPORT_SYMBOL(blkdev_issue_zeroout);