[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))) {
		pr_err_ratelimited("%pg: Error: discard_granularity is 0.\n",
				   bdev);
		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;

	/* make sure that "len << SECTOR_SHIFT" doesn't overflow */
	if (max_sectors > UINT_MAX >> SECTOR_SHIFT)
		max_sectors = UINT_MAX >> SECTOR_SHIFT;
	max_sectors &= ~bs_mask;

	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_SHIFT;

		sector += len;
		nr_sects -= len;
		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))) {
02ff3dd2 CH	51	pr_err_ratelimited("%pg: Error: discard_granularity is 0.\n",
02ff3dd2 CH	52	bdev);
b35fd742 CL	53	return -EOPNOTSUPP;
	54	}
	55
28b2be20 DW	56	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
	57	if ((sector \| nr_sects) & bs_mask)
	58	return -EINVAL;
	59
ba5d7385 ML	60	if (!nr_sects)
ba5d7385 ML	61	return -EINVAL;
a22c4d7e	62
ba5d7385	63	while (nr_sects) {
e3cc28ea CH	64	sector_t req_sects =
e3cc28ea CH	65	min(nr_sects, bio_discard_limit(bdev, sector));
4800bf7b	66
44abff2c	67	bio = blk_next_bio(bio, bdev, 0, REQ_OP_DISCARD, gfp_mask);
4f024f37	68	bio->bi_iter.bi_sector = sector;
4f024f37	69	bio->bi_iter.bi_size = req_sects << 9;
ba5d7385	70	sector += req_sects;
c6e66634	71	nr_sects -= req_sects;
f31e7e40	72
c8123f8c JA	73	/*
	74	* We can loop for a long time in here, if someone does
	75	* full device discards (like mkfs). Be nice and allow
	76	* us to schedule out to avoid softlocking if preempt
	77	* is disabled.
	78	*/
	79	cond_resched();
5dba3089	80	}
38f25255 CH	81
	82	*biop = bio;
	83	return 0;
	84	}
	85	EXPORT_SYMBOL(__blkdev_issue_discard);
	86
	87	/**
	88	* blkdev_issue_discard - queue a discard
	89	* @bdev: blockdev to issue discard for
	90	* @sector: start sector
	91	* @nr_sects: number of sectors to discard
	92	* @gfp_mask: memory allocation flags (for bio_alloc)
38f25255 CH	93	*
	94	* Description:
	95	* Issue a discard request for the sectors in question.
	96	*/
	97	int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
44abff2c	98	sector_t nr_sects, gfp_t gfp_mask)
38f25255	99	{
38f25255 CH	100	struct bio *bio = NULL;
	101	struct blk_plug plug;
	102	int ret;
	103
38f25255	104	blk_start_plug(&plug);
44abff2c	105	ret = __blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask, &bio);
bbd848e0	106	if (!ret && bio) {
4e49ea4a	107	ret = submit_bio_wait(bio);
48920ff2	108	if (ret == -EOPNOTSUPP)
bbd848e0	109	ret = 0;
05bd92dd	110	bio_put(bio);
bbd848e0	111	}
0cfbcafc	112	blk_finish_plug(&plug);
f31e7e40	113
bbd848e0	114	return ret;
f31e7e40 DM	115	}
f31e7e40 DM	116	EXPORT_SYMBOL(blkdev_issue_discard);
3f14d792	117
a6f0788e CK	118	static int __blkdev_issue_write_zeroes(struct block_device *bdev,
a6f0788e CK	119	sector_t sector, sector_t nr_sects, gfp_t gfp_mask,
d928be9f	120	struct bio **biop, unsigned flags)
a6f0788e CK	121	{
	122	struct bio bio = biop;
	123	unsigned int max_write_zeroes_sectors;
a6f0788e	124
a13553c7 ID	125	if (bdev_read_only(bdev))
	126	return -EPERM;
	127
a6f0788e CK	128	/* Ensure that max_write_zeroes_sectors doesn't overflow bi_size */
	129	max_write_zeroes_sectors = bdev_write_zeroes_sectors(bdev);
	130
	131	if (max_write_zeroes_sectors == 0)
	132	return -EOPNOTSUPP;
	133
	134	while (nr_sects) {
0a3140ea	135	bio = blk_next_bio(bio, bdev, 0, REQ_OP_WRITE_ZEROES, gfp_mask);
a6f0788e	136	bio->bi_iter.bi_sector = sector;
d928be9f CH	137	if (flags & BLKDEV_ZERO_NOUNMAP)
d928be9f CH	138	bio->bi_opf \|= REQ_NOUNMAP;
a6f0788e CK	139
	140	if (nr_sects > max_write_zeroes_sectors) {
	141	bio->bi_iter.bi_size = max_write_zeroes_sectors << 9;
	142	nr_sects -= max_write_zeroes_sectors;
	143	sector += max_write_zeroes_sectors;
	144	} else {
	145	bio->bi_iter.bi_size = nr_sects << 9;
	146	nr_sects = 0;
	147	}
	148	cond_resched();
	149	}
	150
	151	*biop = bio;
	152	return 0;
	153	}
	154
615d22a5 DLM	155	/*
	156	* Convert a number of 512B sectors to a number of pages.
	157	* The result is limited to a number of pages that can fit into a BIO.
	158	* Also make sure that the result is always at least 1 (page) for the cases
	159	* where nr_sects is lower than the number of sectors in a page.
	160	*/
	161	static unsigned int __blkdev_sectors_to_bio_pages(sector_t nr_sects)
	162	{
09c2c359	163	sector_t pages = DIV_ROUND_UP_SECTOR_T(nr_sects, PAGE_SIZE / 512);
615d22a5	164
a8affc03	165	return min(pages, (sector_t)BIO_MAX_VECS);
615d22a5 DLM	166	}
615d22a5 DLM	167
425a4dba ID	168	static int __blkdev_issue_zero_pages(struct block_device *bdev,
	169	sector_t sector, sector_t nr_sects, gfp_t gfp_mask,
	170	struct bio **biop)
	171	{
425a4dba ID	172	struct bio bio = biop;
	173	int bi_size = 0;
	174	unsigned int sz;
	175
a13553c7 ID	176	if (bdev_read_only(bdev))
	177	return -EPERM;
	178
425a4dba	179	while (nr_sects != 0) {
0a3140ea CK	180	bio = blk_next_bio(bio, bdev, __blkdev_sectors_to_bio_pages(nr_sects),
0a3140ea CK	181	REQ_OP_WRITE, gfp_mask);
425a4dba	182	bio->bi_iter.bi_sector = sector;
425a4dba ID	183
	184	while (nr_sects != 0) {
	185	sz = min((sector_t) PAGE_SIZE, nr_sects << 9);
	186	bi_size = bio_add_page(bio, ZERO_PAGE(0), sz, 0);
	187	nr_sects -= bi_size >> 9;
	188	sector += bi_size >> 9;
	189	if (bi_size < sz)
	190	break;
	191	}
	192	cond_resched();
	193	}
	194
	195	*biop = bio;
	196	return 0;
	197	}
	198
3f14d792	199	/**
e73c23ff	200	* __blkdev_issue_zeroout - generate number of zero filed write bios
3f14d792 DM	201	* @bdev: blockdev to issue
	202	* @sector: start sector
	203	* @nr_sects: number of sectors to write
	204	* @gfp_mask: memory allocation flags (for bio_alloc)
e73c23ff	205	* @biop: pointer to anchor bio
ee472d83	206	* @flags: controls detailed behavior
3f14d792 DM	207	*
3f14d792 DM	208	* Description:
ee472d83 CH	209	* Zero-fill a block range, either using hardware offload or by explicitly
	210	* writing zeroes to the device.
	211	*
	212	* If a device is using logical block provisioning, the underlying space will
	213	* not be released if %flags contains BLKDEV_ZERO_NOUNMAP.
cb365b96 CH	214	*
	215	* If %flags contains BLKDEV_ZERO_NOFALLBACK, the function will return
	216	* -EOPNOTSUPP if no explicit hardware offload for zeroing is provided.
3f14d792	217	*/
e73c23ff CK	218	int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
e73c23ff CK	219	sector_t nr_sects, gfp_t gfp_mask, struct bio **biop,
ee472d83	220	unsigned flags)
3f14d792	221	{
18edc8ea	222	int ret;
28b2be20 DW	223	sector_t bs_mask;
	224
	225	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
	226	if ((sector \| nr_sects) & bs_mask)
	227	return -EINVAL;
3f14d792	228
a6f0788e	229	ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects, gfp_mask,
d928be9f	230	biop, flags);
cb365b96	231	if (ret != -EOPNOTSUPP \|\| (flags & BLKDEV_ZERO_NOFALLBACK))
425a4dba	232	return ret;
3f14d792	233
425a4dba ID	234	return __blkdev_issue_zero_pages(bdev, sector, nr_sects, gfp_mask,
425a4dba ID	235	biop);
3f14d792	236	}
e73c23ff	237	EXPORT_SYMBOL(__blkdev_issue_zeroout);
579e8f3c MP	238
	239	/**
	240	* blkdev_issue_zeroout - zero-fill a block range
	241	* @bdev: blockdev to write
	242	* @sector: start sector
	243	* @nr_sects: number of sectors to write
	244	* @gfp_mask: memory allocation flags (for bio_alloc)
ee472d83	245	* @flags: controls detailed behavior
579e8f3c MP	246	*
579e8f3c MP	247	* Description:
ee472d83 CH	248	* Zero-fill a block range, either using hardware offload or by explicitly
	249	* writing zeroes to the device. See __blkdev_issue_zeroout() for the
	250	* valid values for %flags.
579e8f3c	251	*/
579e8f3c	252	int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
ee472d83	253	sector_t nr_sects, gfp_t gfp_mask, unsigned flags)
579e8f3c	254	{
d5ce4c31 ID	255	int ret = 0;
	256	sector_t bs_mask;
	257	struct bio *bio;
e73c23ff	258	struct blk_plug plug;
d5ce4c31	259	bool try_write_zeroes = !!bdev_write_zeroes_sectors(bdev);
d93ba7a5	260
d5ce4c31 ID	261	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
	262	if ((sector \| nr_sects) & bs_mask)
	263	return -EINVAL;
	264
	265	retry:
	266	bio = NULL;
e73c23ff	267	blk_start_plug(&plug);
d5ce4c31 ID	268	if (try_write_zeroes) {
	269	ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects,
	270	gfp_mask, &bio, flags);
	271	} else if (!(flags & BLKDEV_ZERO_NOFALLBACK)) {
	272	ret = __blkdev_issue_zero_pages(bdev, sector, nr_sects,
	273	gfp_mask, &bio);
	274	} else {
	275	/* No zeroing offload support */
	276	ret = -EOPNOTSUPP;
	277	}
e73c23ff CK	278	if (ret == 0 && bio) {
	279	ret = submit_bio_wait(bio);
	280	bio_put(bio);
	281	}
	282	blk_finish_plug(&plug);
d5ce4c31 ID	283	if (ret && try_write_zeroes) {
	284	if (!(flags & BLKDEV_ZERO_NOFALLBACK)) {
	285	try_write_zeroes = false;
	286	goto retry;
	287	}
	288	if (!bdev_write_zeroes_sectors(bdev)) {
	289	/*
	290	* Zeroing offload support was indicated, but the
	291	* device reported ILLEGAL REQUEST (for some devices
	292	* there is no non-destructive way to verify whether
	293	* WRITE ZEROES is actually supported).
	294	*/
	295	ret = -EOPNOTSUPP;
	296	}
	297	}
579e8f3c	298
e73c23ff	299	return ret;
579e8f3c	300	}
3f14d792	301	EXPORT_SYMBOL(blkdev_issue_zeroout);
44abff2c CH	302
	303	int blkdev_issue_secure_erase(struct block_device *bdev, sector_t sector,
	304	sector_t nr_sects, gfp_t gfp)
	305	{
	306	sector_t bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
	307	unsigned int max_sectors = bdev_max_secure_erase_sectors(bdev);
	308	struct bio *bio = NULL;
	309	struct blk_plug plug;
	310	int ret = 0;
	311
c4fa3684 MP	312	/* make sure that "len << SECTOR_SHIFT" doesn't overflow */
	313	if (max_sectors > UINT_MAX >> SECTOR_SHIFT)
	314	max_sectors = UINT_MAX >> SECTOR_SHIFT;
	315	max_sectors &= ~bs_mask;
	316
44abff2c CH	317	if (max_sectors == 0)
	318	return -EOPNOTSUPP;
	319	if ((sector \| nr_sects) & bs_mask)
	320	return -EINVAL;
	321	if (bdev_read_only(bdev))
	322	return -EPERM;
	323
	324	blk_start_plug(&plug);
	325	for (;;) {
	326	unsigned int len = min_t(sector_t, nr_sects, max_sectors);
	327
	328	bio = blk_next_bio(bio, bdev, 0, REQ_OP_SECURE_ERASE, gfp);
	329	bio->bi_iter.bi_sector = sector;
c4fa3684	330	bio->bi_iter.bi_size = len << SECTOR_SHIFT;
44abff2c	331
c4fa3684 MP	332	sector += len;
c4fa3684 MP	333	nr_sects -= len;
44abff2c CH	334	if (!nr_sects) {
	335	ret = submit_bio_wait(bio);
	336	bio_put(bio);
	337	break;
	338	}
	339	cond_resched();
	340	}
	341	blk_finish_plug(&plug);
	342
	343	return ret;
	344	}
	345	EXPORT_SYMBOL(blkdev_issue_secure_erase);