[linux-block.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 sector_t bio_discard_limit(struct block_device *bdev, sector_t sector)
{
	unsigned int discard_granularity = bdev_discard_granularity(bdev);
	sector_t granularity_aligned_sector;

	if (bdev_is_partition(bdev))
		sector += bdev->bd_start_sect;

	granularity_aligned_sector =
		round_up(sector, discard_granularity >> SECTOR_SHIFT);

	/*
	 * Make sure subsequent bios start aligned to the discard granularity if
	 * it needs to be split.
	 */
	if (granularity_aligned_sector != sector)
		return granularity_aligned_sector - sector;

	/*
	 * Align the bio size to the discard granularity to make splitting the bio
	 * at discard granularity boundaries easier in the driver if needed.
	 */
	return round_down(UINT_MAX, discard_granularity) >> SECTOR_SHIFT;
}

int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
		sector_t nr_sects, gfp_t gfp_mask, struct bio **biop)
{
	struct bio *bio = *biop;
	sector_t bs_mask;

	if (bdev_read_only(bdev))
		return -EPERM;
	if (!bdev_max_discard_sectors(bdev))
		return -EOPNOTSUPP;

	/* In case the discard granularity isn't set by buggy device driver */
	if (WARN_ON_ONCE(!bdev_discard_granularity(bdev))) {
		char dev_name[BDEVNAME_SIZE];

		bdevname(bdev, dev_name);
		pr_err_ratelimited("%s: Error: discard_granularity is 0.\n", dev_name);
		return -EOPNOTSUPP;
	}

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

	if (!nr_sects)
		return -EINVAL;

	while (nr_sects) {
		sector_t req_sects =
			min(nr_sects, bio_discard_limit(bdev, sector));

		bio = blk_next_bio(bio, bdev, 0, REQ_OP_DISCARD, gfp_mask);
		bio->bi_iter.bi_sector = sector;
		bio->bi_iter.bi_size = req_sects << 9;
		sector += req_sects;
		nr_sects -= req_sects;

		/*
		 * 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;
}
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)
 *
 * 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)
{
	struct bio *bio = NULL;
	struct blk_plug plug;
	int ret;

	blk_start_plug(&plug);
	ret = __blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask, &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);

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;

	if (bdev_read_only(bdev))
		return -EPERM;

	/* 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 = blk_next_bio(bio, bdev, 0, REQ_OP_WRITE_ZEROES, gfp_mask);
		bio->bi_iter.bi_sector = sector;
		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_VECS);
}

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 bio *bio = *biop;
	int bi_size = 0;
	unsigned int sz;

	if (bdev_read_only(bdev))
		return -EPERM;

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

		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);

int blkdev_issue_secure_erase(struct block_device *bdev, sector_t sector,
		sector_t nr_sects, gfp_t gfp)
{
	sector_t bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
	unsigned int max_sectors = bdev_max_secure_erase_sectors(bdev);
	struct bio *bio = NULL;
	struct blk_plug plug;
	int ret = 0;

	if (max_sectors == 0)
		return -EOPNOTSUPP;
	if ((sector | nr_sects) & bs_mask)
		return -EINVAL;
	if (bdev_read_only(bdev))
		return -EPERM;

	blk_start_plug(&plug);
	for (;;) {
		unsigned int len = min_t(sector_t, nr_sects, max_sectors);

		bio = blk_next_bio(bio, bdev, 0, REQ_OP_SECURE_ERASE, gfp);
		bio->bi_iter.bi_sector = sector;
		bio->bi_iter.bi_size = len;

		sector += len << SECTOR_SHIFT;
		nr_sects -= len << SECTOR_SHIFT;
		if (!nr_sects) {
			ret = submit_bio_wait(bio);
			bio_put(bio);
			break;
		}
		cond_resched();
	}
	blk_finish_plug(&plug);

	return ret;
}
EXPORT_SYMBOL(blkdev_issue_secure_erase);
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
e3cc28ea CH	13	static sector_t bio_discard_limit(struct block_device *bdev, sector_t sector)
e3cc28ea CH	14	{
7b47ef52	15	unsigned int discard_granularity = bdev_discard_granularity(bdev);
e3cc28ea CH	16	sector_t granularity_aligned_sector;
	17
	18	if (bdev_is_partition(bdev))
	19	sector += bdev->bd_start_sect;
	20
	21	granularity_aligned_sector =
	22	round_up(sector, discard_granularity >> SECTOR_SHIFT);
	23
	24	/*
	25	* Make sure subsequent bios start aligned to the discard granularity if
	26	* it needs to be split.
	27	*/
	28	if (granularity_aligned_sector != sector)
	29	return granularity_aligned_sector - sector;
	30
	31	/*
	32	* Align the bio size to the discard granularity to make splitting the bio
	33	* at discard granularity boundaries easier in the driver if needed.
	34	*/
	35	return round_down(UINT_MAX, discard_granularity) >> SECTOR_SHIFT;
	36	}
	37
38f25255	38	int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
44abff2c	39	sector_t nr_sects, gfp_t gfp_mask, struct bio **biop)
f31e7e40	40	{
38f25255	41	struct bio bio = biop;
e3cc28ea	42	sector_t bs_mask;
f31e7e40	43
a13553c7 ID	44	if (bdev_read_only(bdev))
a13553c7 ID	45	return -EPERM;
44abff2c CH	46	if (!bdev_max_discard_sectors(bdev))
44abff2c CH	47	return -EOPNOTSUPP;
f31e7e40	48
b35fd742	49	/* In case the discard granularity isn't set by buggy device driver */
7b47ef52	50	if (WARN_ON_ONCE(!bdev_discard_granularity(bdev))) {
b35fd742 CL	51	char dev_name[BDEVNAME_SIZE];
	52
	53	bdevname(bdev, dev_name);
	54	pr_err_ratelimited("%s: Error: discard_granularity is 0.\n", dev_name);
	55	return -EOPNOTSUPP;
	56	}
	57
28b2be20 DW	58	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
	59	if ((sector \| nr_sects) & bs_mask)
	60	return -EINVAL;
	61
ba5d7385 ML	62	if (!nr_sects)
ba5d7385 ML	63	return -EINVAL;
a22c4d7e	64
ba5d7385	65	while (nr_sects) {
e3cc28ea CH	66	sector_t req_sects =
e3cc28ea CH	67	min(nr_sects, bio_discard_limit(bdev, sector));
4800bf7b	68
44abff2c	69	bio = blk_next_bio(bio, bdev, 0, REQ_OP_DISCARD, gfp_mask);
4f024f37	70	bio->bi_iter.bi_sector = sector;
4f024f37	71	bio->bi_iter.bi_size = req_sects << 9;
ba5d7385	72	sector += req_sects;
c6e66634	73	nr_sects -= req_sects;
f31e7e40	74
c8123f8c JA	75	/*
	76	* We can loop for a long time in here, if someone does
	77	* full device discards (like mkfs). Be nice and allow
	78	* us to schedule out to avoid softlocking if preempt
	79	* is disabled.
	80	*/
	81	cond_resched();
5dba3089	82	}
38f25255 CH	83
	84	*biop = bio;
	85	return 0;
	86	}
	87	EXPORT_SYMBOL(__blkdev_issue_discard);
	88
	89	/**
	90	* blkdev_issue_discard - queue a discard
	91	* @bdev: blockdev to issue discard for
	92	* @sector: start sector
	93	* @nr_sects: number of sectors to discard
	94	* @gfp_mask: memory allocation flags (for bio_alloc)
38f25255 CH	95	*
	96	* Description:
	97	* Issue a discard request for the sectors in question.
	98	*/
	99	int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
44abff2c	100	sector_t nr_sects, gfp_t gfp_mask)
38f25255	101	{
38f25255 CH	102	struct bio *bio = NULL;
	103	struct blk_plug plug;
	104	int ret;
	105
38f25255	106	blk_start_plug(&plug);
44abff2c	107	ret = __blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask, &bio);
bbd848e0	108	if (!ret && bio) {
4e49ea4a	109	ret = submit_bio_wait(bio);
48920ff2	110	if (ret == -EOPNOTSUPP)
bbd848e0	111	ret = 0;
05bd92dd	112	bio_put(bio);
bbd848e0	113	}
0cfbcafc	114	blk_finish_plug(&plug);
f31e7e40	115
bbd848e0	116	return ret;
f31e7e40 DM	117	}
f31e7e40 DM	118	EXPORT_SYMBOL(blkdev_issue_discard);
3f14d792	119
a6f0788e CK	120	static int __blkdev_issue_write_zeroes(struct block_device *bdev,
a6f0788e CK	121	sector_t sector, sector_t nr_sects, gfp_t gfp_mask,
d928be9f	122	struct bio **biop, unsigned flags)
a6f0788e CK	123	{
	124	struct bio bio = biop;
	125	unsigned int max_write_zeroes_sectors;
a6f0788e	126
a13553c7 ID	127	if (bdev_read_only(bdev))
	128	return -EPERM;
	129
a6f0788e CK	130	/* Ensure that max_write_zeroes_sectors doesn't overflow bi_size */
	131	max_write_zeroes_sectors = bdev_write_zeroes_sectors(bdev);
	132
	133	if (max_write_zeroes_sectors == 0)
	134	return -EOPNOTSUPP;
	135
	136	while (nr_sects) {
0a3140ea	137	bio = blk_next_bio(bio, bdev, 0, REQ_OP_WRITE_ZEROES, gfp_mask);
a6f0788e	138	bio->bi_iter.bi_sector = sector;
d928be9f CH	139	if (flags & BLKDEV_ZERO_NOUNMAP)
d928be9f CH	140	bio->bi_opf \|= REQ_NOUNMAP;
a6f0788e CK	141
	142	if (nr_sects > max_write_zeroes_sectors) {
	143	bio->bi_iter.bi_size = max_write_zeroes_sectors << 9;
	144	nr_sects -= max_write_zeroes_sectors;
	145	sector += max_write_zeroes_sectors;
	146	} else {
	147	bio->bi_iter.bi_size = nr_sects << 9;
	148	nr_sects = 0;
	149	}
	150	cond_resched();
	151	}
	152
	153	*biop = bio;
	154	return 0;
	155	}
	156
615d22a5 DLM	157	/*
	158	* Convert a number of 512B sectors to a number of pages.
	159	* The result is limited to a number of pages that can fit into a BIO.
	160	* Also make sure that the result is always at least 1 (page) for the cases
	161	* where nr_sects is lower than the number of sectors in a page.
	162	*/
	163	static unsigned int __blkdev_sectors_to_bio_pages(sector_t nr_sects)
	164	{
09c2c359	165	sector_t pages = DIV_ROUND_UP_SECTOR_T(nr_sects, PAGE_SIZE / 512);
615d22a5	166
a8affc03	167	return min(pages, (sector_t)BIO_MAX_VECS);
615d22a5 DLM	168	}
615d22a5 DLM	169
425a4dba ID	170	static int __blkdev_issue_zero_pages(struct block_device *bdev,
	171	sector_t sector, sector_t nr_sects, gfp_t gfp_mask,
	172	struct bio **biop)
	173	{
425a4dba ID	174	struct bio bio = biop;
	175	int bi_size = 0;
	176	unsigned int sz;
	177
a13553c7 ID	178	if (bdev_read_only(bdev))
	179	return -EPERM;
	180
425a4dba	181	while (nr_sects != 0) {
0a3140ea CK	182	bio = blk_next_bio(bio, bdev, __blkdev_sectors_to_bio_pages(nr_sects),
0a3140ea CK	183	REQ_OP_WRITE, gfp_mask);
425a4dba	184	bio->bi_iter.bi_sector = sector;
425a4dba ID	185
	186	while (nr_sects != 0) {
	187	sz = min((sector_t) PAGE_SIZE, nr_sects << 9);
	188	bi_size = bio_add_page(bio, ZERO_PAGE(0), sz, 0);
	189	nr_sects -= bi_size >> 9;
	190	sector += bi_size >> 9;
	191	if (bi_size < sz)
	192	break;
	193	}
	194	cond_resched();
	195	}
	196
	197	*biop = bio;
	198	return 0;
	199	}
	200
3f14d792	201	/**
e73c23ff	202	* __blkdev_issue_zeroout - generate number of zero filed write bios
3f14d792 DM	203	* @bdev: blockdev to issue
	204	* @sector: start sector
	205	* @nr_sects: number of sectors to write
	206	* @gfp_mask: memory allocation flags (for bio_alloc)
e73c23ff	207	* @biop: pointer to anchor bio
ee472d83	208	* @flags: controls detailed behavior
3f14d792 DM	209	*
3f14d792 DM	210	* Description:
ee472d83 CH	211	* Zero-fill a block range, either using hardware offload or by explicitly
	212	* writing zeroes to the device.
	213	*
	214	* If a device is using logical block provisioning, the underlying space will
	215	* not be released if %flags contains BLKDEV_ZERO_NOUNMAP.
cb365b96 CH	216	*
	217	* If %flags contains BLKDEV_ZERO_NOFALLBACK, the function will return
	218	* -EOPNOTSUPP if no explicit hardware offload for zeroing is provided.
3f14d792	219	*/
e73c23ff CK	220	int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
e73c23ff CK	221	sector_t nr_sects, gfp_t gfp_mask, struct bio **biop,
ee472d83	222	unsigned flags)
3f14d792	223	{
18edc8ea	224	int ret;
28b2be20 DW	225	sector_t bs_mask;
	226
	227	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
	228	if ((sector \| nr_sects) & bs_mask)
	229	return -EINVAL;
3f14d792	230
a6f0788e	231	ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects, gfp_mask,
d928be9f	232	biop, flags);
cb365b96	233	if (ret != -EOPNOTSUPP \|\| (flags & BLKDEV_ZERO_NOFALLBACK))
425a4dba	234	return ret;
3f14d792	235
425a4dba ID	236	return __blkdev_issue_zero_pages(bdev, sector, nr_sects, gfp_mask,
425a4dba ID	237	biop);
3f14d792	238	}
e73c23ff	239	EXPORT_SYMBOL(__blkdev_issue_zeroout);
579e8f3c MP	240
	241	/**
	242	* blkdev_issue_zeroout - zero-fill a block range
	243	* @bdev: blockdev to write
	244	* @sector: start sector
	245	* @nr_sects: number of sectors to write
	246	* @gfp_mask: memory allocation flags (for bio_alloc)
ee472d83	247	* @flags: controls detailed behavior
579e8f3c MP	248	*
579e8f3c MP	249	* Description:
ee472d83 CH	250	* Zero-fill a block range, either using hardware offload or by explicitly
	251	* writing zeroes to the device. See __blkdev_issue_zeroout() for the
	252	* valid values for %flags.
579e8f3c	253	*/
579e8f3c	254	int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
ee472d83	255	sector_t nr_sects, gfp_t gfp_mask, unsigned flags)
579e8f3c	256	{
d5ce4c31 ID	257	int ret = 0;
	258	sector_t bs_mask;
	259	struct bio *bio;
e73c23ff	260	struct blk_plug plug;
d5ce4c31	261	bool try_write_zeroes = !!bdev_write_zeroes_sectors(bdev);
d93ba7a5	262
d5ce4c31 ID	263	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
	264	if ((sector \| nr_sects) & bs_mask)
	265	return -EINVAL;
	266
	267	retry:
	268	bio = NULL;
e73c23ff	269	blk_start_plug(&plug);
d5ce4c31 ID	270	if (try_write_zeroes) {
	271	ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects,
	272	gfp_mask, &bio, flags);
	273	} else if (!(flags & BLKDEV_ZERO_NOFALLBACK)) {
	274	ret = __blkdev_issue_zero_pages(bdev, sector, nr_sects,
	275	gfp_mask, &bio);
	276	} else {
	277	/* No zeroing offload support */
	278	ret = -EOPNOTSUPP;
	279	}
e73c23ff CK	280	if (ret == 0 && bio) {
	281	ret = submit_bio_wait(bio);
	282	bio_put(bio);
	283	}
	284	blk_finish_plug(&plug);
d5ce4c31 ID	285	if (ret && try_write_zeroes) {
	286	if (!(flags & BLKDEV_ZERO_NOFALLBACK)) {
	287	try_write_zeroes = false;
	288	goto retry;
	289	}
	290	if (!bdev_write_zeroes_sectors(bdev)) {
	291	/*
	292	* Zeroing offload support was indicated, but the
	293	* device reported ILLEGAL REQUEST (for some devices
	294	* there is no non-destructive way to verify whether
	295	* WRITE ZEROES is actually supported).
	296	*/
	297	ret = -EOPNOTSUPP;
	298	}
	299	}
579e8f3c	300
e73c23ff	301	return ret;
579e8f3c	302	}
3f14d792	303	EXPORT_SYMBOL(blkdev_issue_zeroout);
44abff2c CH	304
	305	int blkdev_issue_secure_erase(struct block_device *bdev, sector_t sector,
	306	sector_t nr_sects, gfp_t gfp)
	307	{
	308	sector_t bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
	309	unsigned int max_sectors = bdev_max_secure_erase_sectors(bdev);
	310	struct bio *bio = NULL;
	311	struct blk_plug plug;
	312	int ret = 0;
	313
	314	if (max_sectors == 0)
	315	return -EOPNOTSUPP;
	316	if ((sector \| nr_sects) & bs_mask)
	317	return -EINVAL;
	318	if (bdev_read_only(bdev))
	319	return -EPERM;
	320
	321	blk_start_plug(&plug);
	322	for (;;) {
	323	unsigned int len = min_t(sector_t, nr_sects, max_sectors);
	324
	325	bio = blk_next_bio(bio, bdev, 0, REQ_OP_SECURE_ERASE, gfp);
	326	bio->bi_iter.bi_sector = sector;
	327	bio->bi_iter.bi_size = len;
	328
	329	sector += len << SECTOR_SHIFT;
	330	nr_sects -= len << SECTOR_SHIFT;
	331	if (!nr_sects) {
	332	ret = submit_bio_wait(bio);
	333	bio_put(bio);
	334	break;
	335	}
	336	cond_resched();
	337	}
	338	blk_finish_plug(&plug);
	339
	340	return ret;
	341	}
	342	EXPORT_SYMBOL(blkdev_issue_secure_erase);