[linux-2.6-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;
}

struct bio *blk_alloc_discard_bio(struct block_device *bdev,
		sector_t *sector, sector_t *nr_sects, gfp_t gfp_mask)
{
	sector_t bio_sects = min(*nr_sects, bio_discard_limit(bdev, *sector));
	struct bio *bio;

	if (!bio_sects)
		return NULL;

	bio = bio_alloc(bdev, 0, REQ_OP_DISCARD, gfp_mask);
	if (!bio)
		return NULL;
	bio->bi_iter.bi_sector = *sector;
	bio->bi_iter.bi_size = bio_sects << SECTOR_SHIFT;
	*sector += bio_sects;
	*nr_sects -= bio_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();
	return bio;
}

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;

	while ((bio = blk_alloc_discard_bio(bdev, &sector, &nr_sects,
			gfp_mask)))
		*biop = bio_chain_and_submit(*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_sectors;

	if (bdev_read_only(bdev))
		return -EPERM;

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

	if (max_sectors == 0)
		return -EOPNOTSUPP;

	while (nr_sects) {
		unsigned int len = min_t(sector_t, nr_sects, max_sectors);

		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;

		bio->bi_iter.bi_size = len << SECTOR_SHIFT;
		nr_sects -= len;
		sector += len;
		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);
	while (nr_sects) {
		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;
		cond_resched();
	}
	if (bio) {
		ret = submit_bio_wait(bio);
		bio_put(bio);
	}
	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
e8b4869b CH	38	struct bio blk_alloc_discard_bio(struct block_device bdev,
e8b4869b CH	39	sector_t sector, sector_t nr_sects, gfp_t gfp_mask)
f31e7e40	40	{
e8b4869b CH	41	sector_t bio_sects = min(nr_sects, bio_discard_limit(bdev, sector));
e8b4869b CH	42	struct bio *bio;
a22c4d7e	43
e8b4869b CH	44	if (!bio_sects)
e8b4869b CH	45	return NULL;
4800bf7b	46
e8b4869b CH	47	bio = bio_alloc(bdev, 0, REQ_OP_DISCARD, gfp_mask);
	48	if (!bio)
	49	return NULL;
	50	bio->bi_iter.bi_sector = *sector;
	51	bio->bi_iter.bi_size = bio_sects << SECTOR_SHIFT;
	52	*sector += bio_sects;
	53	*nr_sects -= bio_sects;
	54	/*
	55	* We can loop for a long time in here if someone does full device
	56	* discards (like mkfs). Be nice and allow us to schedule out to avoid
	57	* softlocking if preempt is disabled.
	58	*/
	59	cond_resched();
	60	return bio;
	61	}
f31e7e40	62
e8b4869b CH	63	int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
	64	sector_t nr_sects, gfp_t gfp_mask, struct bio **biop)
	65	{
	66	struct bio *bio;
38f25255	67
e8b4869b CH	68	while ((bio = blk_alloc_discard_bio(bdev, &sector, &nr_sects,
	69	gfp_mask)))
	70	biop = bio_chain_and_submit(biop, bio);
38f25255 CH	71	return 0;
	72	}
	73	EXPORT_SYMBOL(__blkdev_issue_discard);
	74
	75	/**
	76	* blkdev_issue_discard - queue a discard
	77	* @bdev: blockdev to issue discard for
	78	* @sector: start sector
	79	* @nr_sects: number of sectors to discard
	80	* @gfp_mask: memory allocation flags (for bio_alloc)
38f25255 CH	81	*
	82	* Description:
	83	* Issue a discard request for the sectors in question.
	84	*/
	85	int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
44abff2c	86	sector_t nr_sects, gfp_t gfp_mask)
38f25255	87	{
38f25255 CH	88	struct bio *bio = NULL;
	89	struct blk_plug plug;
	90	int ret;
	91
38f25255	92	blk_start_plug(&plug);
44abff2c	93	ret = __blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask, &bio);
bbd848e0	94	if (!ret && bio) {
4e49ea4a	95	ret = submit_bio_wait(bio);
48920ff2	96	if (ret == -EOPNOTSUPP)
bbd848e0	97	ret = 0;
05bd92dd	98	bio_put(bio);
bbd848e0	99	}
0cfbcafc	100	blk_finish_plug(&plug);
f31e7e40	101
bbd848e0	102	return ret;
f31e7e40 DM	103	}
f31e7e40 DM	104	EXPORT_SYMBOL(blkdev_issue_discard);
3f14d792	105
a6f0788e CK	106	static int __blkdev_issue_write_zeroes(struct block_device *bdev,
a6f0788e CK	107	sector_t sector, sector_t nr_sects, gfp_t gfp_mask,
d928be9f	108	struct bio **biop, unsigned flags)
a6f0788e CK	109	{
a6f0788e CK	110	struct bio bio = biop;
76a27e1b	111	unsigned int max_sectors;
a6f0788e	112
a13553c7 ID	113	if (bdev_read_only(bdev))
	114	return -EPERM;
	115
76a27e1b KB	116	/* Ensure that max_sectors doesn't overflow bi_size */
76a27e1b KB	117	max_sectors = bdev_write_zeroes_sectors(bdev);
a6f0788e	118
76a27e1b	119	if (max_sectors == 0)
a6f0788e CK	120	return -EOPNOTSUPP;
	121
	122	while (nr_sects) {
76a27e1b KB	123	unsigned int len = min_t(sector_t, nr_sects, max_sectors);
76a27e1b KB	124
0a3140ea	125	bio = blk_next_bio(bio, bdev, 0, REQ_OP_WRITE_ZEROES, gfp_mask);
a6f0788e	126	bio->bi_iter.bi_sector = sector;
d928be9f CH	127	if (flags & BLKDEV_ZERO_NOUNMAP)
d928be9f CH	128	bio->bi_opf \|= REQ_NOUNMAP;
a6f0788e	129
76a27e1b KB	130	bio->bi_iter.bi_size = len << SECTOR_SHIFT;
	131	nr_sects -= len;
	132	sector += len;
a6f0788e CK	133	cond_resched();
	134	}
	135
	136	*biop = bio;
	137	return 0;
	138	}
	139
615d22a5 DLM	140	/*
	141	* Convert a number of 512B sectors to a number of pages.
	142	* The result is limited to a number of pages that can fit into a BIO.
	143	* Also make sure that the result is always at least 1 (page) for the cases
	144	* where nr_sects is lower than the number of sectors in a page.
	145	*/
	146	static unsigned int __blkdev_sectors_to_bio_pages(sector_t nr_sects)
	147	{
09c2c359	148	sector_t pages = DIV_ROUND_UP_SECTOR_T(nr_sects, PAGE_SIZE / 512);
615d22a5	149
a8affc03	150	return min(pages, (sector_t)BIO_MAX_VECS);
615d22a5 DLM	151	}
615d22a5 DLM	152
425a4dba ID	153	static int __blkdev_issue_zero_pages(struct block_device *bdev,
	154	sector_t sector, sector_t nr_sects, gfp_t gfp_mask,
	155	struct bio **biop)
	156	{
425a4dba ID	157	struct bio bio = biop;
	158	int bi_size = 0;
	159	unsigned int sz;
	160
a13553c7 ID	161	if (bdev_read_only(bdev))
	162	return -EPERM;
	163
425a4dba	164	while (nr_sects != 0) {
0a3140ea CK	165	bio = blk_next_bio(bio, bdev, __blkdev_sectors_to_bio_pages(nr_sects),
0a3140ea CK	166	REQ_OP_WRITE, gfp_mask);
425a4dba	167	bio->bi_iter.bi_sector = sector;
425a4dba ID	168
	169	while (nr_sects != 0) {
	170	sz = min((sector_t) PAGE_SIZE, nr_sects << 9);
	171	bi_size = bio_add_page(bio, ZERO_PAGE(0), sz, 0);
	172	nr_sects -= bi_size >> 9;
	173	sector += bi_size >> 9;
	174	if (bi_size < sz)
	175	break;
	176	}
	177	cond_resched();
	178	}
	179
	180	*biop = bio;
	181	return 0;
	182	}
	183
3f14d792	184	/**
e73c23ff	185	* __blkdev_issue_zeroout - generate number of zero filed write bios
3f14d792 DM	186	* @bdev: blockdev to issue
	187	* @sector: start sector
	188	* @nr_sects: number of sectors to write
	189	* @gfp_mask: memory allocation flags (for bio_alloc)
e73c23ff	190	* @biop: pointer to anchor bio
ee472d83	191	* @flags: controls detailed behavior
3f14d792 DM	192	*
3f14d792 DM	193	* Description:
ee472d83 CH	194	* Zero-fill a block range, either using hardware offload or by explicitly
	195	* writing zeroes to the device.
	196	*
	197	* If a device is using logical block provisioning, the underlying space will
	198	* not be released if %flags contains BLKDEV_ZERO_NOUNMAP.
cb365b96 CH	199	*
	200	* If %flags contains BLKDEV_ZERO_NOFALLBACK, the function will return
	201	* -EOPNOTSUPP if no explicit hardware offload for zeroing is provided.
3f14d792	202	*/
e73c23ff CK	203	int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
e73c23ff CK	204	sector_t nr_sects, gfp_t gfp_mask, struct bio **biop,
ee472d83	205	unsigned flags)
3f14d792	206	{
18edc8ea	207	int ret;
28b2be20 DW	208	sector_t bs_mask;
	209
	210	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
	211	if ((sector \| nr_sects) & bs_mask)
	212	return -EINVAL;
3f14d792	213
a6f0788e	214	ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects, gfp_mask,
d928be9f	215	biop, flags);
cb365b96	216	if (ret != -EOPNOTSUPP \|\| (flags & BLKDEV_ZERO_NOFALLBACK))
425a4dba	217	return ret;
3f14d792	218
425a4dba ID	219	return __blkdev_issue_zero_pages(bdev, sector, nr_sects, gfp_mask,
425a4dba ID	220	biop);
3f14d792	221	}
e73c23ff	222	EXPORT_SYMBOL(__blkdev_issue_zeroout);
579e8f3c MP	223
	224	/**
	225	* blkdev_issue_zeroout - zero-fill a block range
	226	* @bdev: blockdev to write
	227	* @sector: start sector
	228	* @nr_sects: number of sectors to write
	229	* @gfp_mask: memory allocation flags (for bio_alloc)
ee472d83	230	* @flags: controls detailed behavior
579e8f3c MP	231	*
579e8f3c MP	232	* Description:
ee472d83 CH	233	* Zero-fill a block range, either using hardware offload or by explicitly
	234	* writing zeroes to the device. See __blkdev_issue_zeroout() for the
	235	* valid values for %flags.
579e8f3c	236	*/
579e8f3c	237	int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
ee472d83	238	sector_t nr_sects, gfp_t gfp_mask, unsigned flags)
579e8f3c	239	{
d5ce4c31 ID	240	int ret = 0;
	241	sector_t bs_mask;
	242	struct bio *bio;
e73c23ff	243	struct blk_plug plug;
d5ce4c31	244	bool try_write_zeroes = !!bdev_write_zeroes_sectors(bdev);
d93ba7a5	245
d5ce4c31 ID	246	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
	247	if ((sector \| nr_sects) & bs_mask)
	248	return -EINVAL;
	249
	250	retry:
	251	bio = NULL;
e73c23ff	252	blk_start_plug(&plug);
d5ce4c31 ID	253	if (try_write_zeroes) {
	254	ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects,
	255	gfp_mask, &bio, flags);
	256	} else if (!(flags & BLKDEV_ZERO_NOFALLBACK)) {
	257	ret = __blkdev_issue_zero_pages(bdev, sector, nr_sects,
	258	gfp_mask, &bio);
	259	} else {
	260	/* No zeroing offload support */
	261	ret = -EOPNOTSUPP;
	262	}
e73c23ff CK	263	if (ret == 0 && bio) {
	264	ret = submit_bio_wait(bio);
	265	bio_put(bio);
	266	}
	267	blk_finish_plug(&plug);
bf5e3a30	268	if (ret && try_write_zeroes) {
d5ce4c31 ID	269	if (!(flags & BLKDEV_ZERO_NOFALLBACK)) {
	270	try_write_zeroes = false;
	271	goto retry;
	272	}
	273	if (!bdev_write_zeroes_sectors(bdev)) {
	274	/*
	275	* Zeroing offload support was indicated, but the
	276	* device reported ILLEGAL REQUEST (for some devices
	277	* there is no non-destructive way to verify whether
	278	* WRITE ZEROES is actually supported).
	279	*/
	280	ret = -EOPNOTSUPP;
	281	}
	282	}
579e8f3c	283
e73c23ff	284	return ret;
579e8f3c	285	}
3f14d792	286	EXPORT_SYMBOL(blkdev_issue_zeroout);
44abff2c CH	287
	288	int blkdev_issue_secure_erase(struct block_device *bdev, sector_t sector,
	289	sector_t nr_sects, gfp_t gfp)
	290	{
	291	sector_t bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
	292	unsigned int max_sectors = bdev_max_secure_erase_sectors(bdev);
	293	struct bio *bio = NULL;
	294	struct blk_plug plug;
	295	int ret = 0;
	296
c4fa3684 MP	297	/* make sure that "len << SECTOR_SHIFT" doesn't overflow */
	298	if (max_sectors > UINT_MAX >> SECTOR_SHIFT)
	299	max_sectors = UINT_MAX >> SECTOR_SHIFT;
	300	max_sectors &= ~bs_mask;
	301
44abff2c CH	302	if (max_sectors == 0)
	303	return -EOPNOTSUPP;
	304	if ((sector \| nr_sects) & bs_mask)
	305	return -EINVAL;
	306	if (bdev_read_only(bdev))
	307	return -EPERM;
	308
	309	blk_start_plug(&plug);
5affe497	310	while (nr_sects) {
44abff2c CH	311	unsigned int len = min_t(sector_t, nr_sects, max_sectors);
	312
	313	bio = blk_next_bio(bio, bdev, 0, REQ_OP_SECURE_ERASE, gfp);
	314	bio->bi_iter.bi_sector = sector;
c4fa3684	315	bio->bi_iter.bi_size = len << SECTOR_SHIFT;
44abff2c	316
c4fa3684 MP	317	sector += len;
c4fa3684 MP	318	nr_sects -= len;
44abff2c CH	319	cond_resched();
44abff2c CH	320	}
5affe497 KB	321	if (bio) {
	322	ret = submit_bio_wait(bio);
	323	bio_put(bio);
	324	}
44abff2c CH	325	blk_finish_plug(&plug);
	326
	327	return ret;
	328	}
	329	EXPORT_SYMBOL(blkdev_issue_secure_erase);