[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;
}

static void await_bio_endio(struct bio *bio)
{
	complete(bio->bi_private);
	bio_put(bio);
}

/*
 * await_bio_chain - ends @bio and waits for every chained bio to complete
 */
static void await_bio_chain(struct bio *bio)
{
	DECLARE_COMPLETION_ONSTACK_MAP(done,
			bio->bi_bdev->bd_disk->lockdep_map);

	bio->bi_private = &done;
	bio->bi_end_io = await_bio_endio;
	bio_endio(bio);
	blk_wait_io(&done);
}

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();
		if (fatal_signal_pending(current)) {
			await_bio_chain(bio);
			return -EINTR;
		}
	}

	*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();
		if (fatal_signal_pending(current)) {
			await_bio_chain(bio);
			return -EINTR;
		}
	}

	*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();
		if (fatal_signal_pending(current)) {
			await_bio_chain(bio);
			return -EINTR;
		}
	}

	*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 && ret != -EINTR && 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 (fatal_signal_pending(current)) {
			await_bio_chain(bio);
			ret = -EINTR;
			bio = NULL;
			break;
		}
	}
	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
8a08c5fd KB	38	static void await_bio_endio(struct bio *bio)
	39	{
	40	complete(bio->bi_private);
	41	bio_put(bio);
	42	}
	43
	44	/*
	45	* await_bio_chain - ends @bio and waits for every chained bio to complete
	46	*/
	47	static void await_bio_chain(struct bio *bio)
	48	{
	49	DECLARE_COMPLETION_ONSTACK_MAP(done,
	50	bio->bi_bdev->bd_disk->lockdep_map);
	51
	52	bio->bi_private = &done;
	53	bio->bi_end_io = await_bio_endio;
	54	bio_endio(bio);
	55	blk_wait_io(&done);
	56	}
	57
38f25255	58	int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
44abff2c	59	sector_t nr_sects, gfp_t gfp_mask, struct bio **biop)
f31e7e40	60	{
38f25255	61	struct bio bio = biop;
e3cc28ea	62	sector_t bs_mask;
f31e7e40	63
a13553c7 ID	64	if (bdev_read_only(bdev))
a13553c7 ID	65	return -EPERM;
44abff2c CH	66	if (!bdev_max_discard_sectors(bdev))
44abff2c CH	67	return -EOPNOTSUPP;
f31e7e40	68
b35fd742	69	/* In case the discard granularity isn't set by buggy device driver */
7b47ef52	70	if (WARN_ON_ONCE(!bdev_discard_granularity(bdev))) {
02ff3dd2 CH	71	pr_err_ratelimited("%pg: Error: discard_granularity is 0.\n",
02ff3dd2 CH	72	bdev);
b35fd742 CL	73	return -EOPNOTSUPP;
	74	}
	75
28b2be20 DW	76	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
	77	if ((sector \| nr_sects) & bs_mask)
	78	return -EINVAL;
	79
ba5d7385 ML	80	if (!nr_sects)
ba5d7385 ML	81	return -EINVAL;
a22c4d7e	82
ba5d7385	83	while (nr_sects) {
e3cc28ea CH	84	sector_t req_sects =
e3cc28ea CH	85	min(nr_sects, bio_discard_limit(bdev, sector));
4800bf7b	86
44abff2c	87	bio = blk_next_bio(bio, bdev, 0, REQ_OP_DISCARD, gfp_mask);
4f024f37	88	bio->bi_iter.bi_sector = sector;
4f024f37	89	bio->bi_iter.bi_size = req_sects << 9;
ba5d7385	90	sector += req_sects;
c6e66634	91	nr_sects -= req_sects;
f31e7e40	92
c8123f8c JA	93	/*
	94	* We can loop for a long time in here, if someone does
	95	* full device discards (like mkfs). Be nice and allow
	96	* us to schedule out to avoid softlocking if preempt
	97	* is disabled.
	98	*/
	99	cond_resched();
8a08c5fd KB	100	if (fatal_signal_pending(current)) {
	101	await_bio_chain(bio);
	102	return -EINTR;
	103	}
5dba3089	104	}
38f25255 CH	105
	106	*biop = bio;
	107	return 0;
	108	}
	109	EXPORT_SYMBOL(__blkdev_issue_discard);
	110
	111	/**
	112	* blkdev_issue_discard - queue a discard
	113	* @bdev: blockdev to issue discard for
	114	* @sector: start sector
	115	* @nr_sects: number of sectors to discard
	116	* @gfp_mask: memory allocation flags (for bio_alloc)
38f25255 CH	117	*
	118	* Description:
	119	* Issue a discard request for the sectors in question.
	120	*/
	121	int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
44abff2c	122	sector_t nr_sects, gfp_t gfp_mask)
38f25255	123	{
38f25255 CH	124	struct bio *bio = NULL;
	125	struct blk_plug plug;
	126	int ret;
	127
38f25255	128	blk_start_plug(&plug);
44abff2c	129	ret = __blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask, &bio);
bbd848e0	130	if (!ret && bio) {
4e49ea4a	131	ret = submit_bio_wait(bio);
48920ff2	132	if (ret == -EOPNOTSUPP)
bbd848e0	133	ret = 0;
05bd92dd	134	bio_put(bio);
bbd848e0	135	}
0cfbcafc	136	blk_finish_plug(&plug);
f31e7e40	137
bbd848e0	138	return ret;
f31e7e40 DM	139	}
f31e7e40 DM	140	EXPORT_SYMBOL(blkdev_issue_discard);
3f14d792	141
a6f0788e CK	142	static int __blkdev_issue_write_zeroes(struct block_device *bdev,
a6f0788e CK	143	sector_t sector, sector_t nr_sects, gfp_t gfp_mask,
d928be9f	144	struct bio **biop, unsigned flags)
a6f0788e CK	145	{
a6f0788e CK	146	struct bio bio = biop;
76a27e1b	147	unsigned int max_sectors;
a6f0788e	148
a13553c7 ID	149	if (bdev_read_only(bdev))
	150	return -EPERM;
	151
76a27e1b KB	152	/* Ensure that max_sectors doesn't overflow bi_size */
76a27e1b KB	153	max_sectors = bdev_write_zeroes_sectors(bdev);
a6f0788e	154
76a27e1b	155	if (max_sectors == 0)
a6f0788e CK	156	return -EOPNOTSUPP;
	157
	158	while (nr_sects) {
76a27e1b KB	159	unsigned int len = min_t(sector_t, nr_sects, max_sectors);
76a27e1b KB	160
0a3140ea	161	bio = blk_next_bio(bio, bdev, 0, REQ_OP_WRITE_ZEROES, gfp_mask);
a6f0788e	162	bio->bi_iter.bi_sector = sector;
d928be9f CH	163	if (flags & BLKDEV_ZERO_NOUNMAP)
d928be9f CH	164	bio->bi_opf \|= REQ_NOUNMAP;
a6f0788e	165
76a27e1b KB	166	bio->bi_iter.bi_size = len << SECTOR_SHIFT;
	167	nr_sects -= len;
	168	sector += len;
a6f0788e	169	cond_resched();
8a08c5fd KB	170	if (fatal_signal_pending(current)) {
	171	await_bio_chain(bio);
	172	return -EINTR;
	173	}
a6f0788e CK	174	}
	175
	176	*biop = bio;
	177	return 0;
	178	}
	179
615d22a5 DLM	180	/*
	181	* Convert a number of 512B sectors to a number of pages.
	182	* The result is limited to a number of pages that can fit into a BIO.
	183	* Also make sure that the result is always at least 1 (page) for the cases
	184	* where nr_sects is lower than the number of sectors in a page.
	185	*/
	186	static unsigned int __blkdev_sectors_to_bio_pages(sector_t nr_sects)
	187	{
09c2c359	188	sector_t pages = DIV_ROUND_UP_SECTOR_T(nr_sects, PAGE_SIZE / 512);
615d22a5	189
a8affc03	190	return min(pages, (sector_t)BIO_MAX_VECS);
615d22a5 DLM	191	}
615d22a5 DLM	192
425a4dba ID	193	static int __blkdev_issue_zero_pages(struct block_device *bdev,
	194	sector_t sector, sector_t nr_sects, gfp_t gfp_mask,
	195	struct bio **biop)
	196	{
425a4dba ID	197	struct bio bio = biop;
	198	int bi_size = 0;
	199	unsigned int sz;
	200
a13553c7 ID	201	if (bdev_read_only(bdev))
	202	return -EPERM;
	203
425a4dba	204	while (nr_sects != 0) {
0a3140ea CK	205	bio = blk_next_bio(bio, bdev, __blkdev_sectors_to_bio_pages(nr_sects),
0a3140ea CK	206	REQ_OP_WRITE, gfp_mask);
425a4dba	207	bio->bi_iter.bi_sector = sector;
425a4dba ID	208
	209	while (nr_sects != 0) {
	210	sz = min((sector_t) PAGE_SIZE, nr_sects << 9);
	211	bi_size = bio_add_page(bio, ZERO_PAGE(0), sz, 0);
	212	nr_sects -= bi_size >> 9;
	213	sector += bi_size >> 9;
	214	if (bi_size < sz)
	215	break;
	216	}
	217	cond_resched();
8a08c5fd KB	218	if (fatal_signal_pending(current)) {
	219	await_bio_chain(bio);
	220	return -EINTR;
	221	}
425a4dba ID	222	}
	223
	224	*biop = bio;
	225	return 0;
	226	}
	227
3f14d792	228	/**
e73c23ff	229	* __blkdev_issue_zeroout - generate number of zero filed write bios
3f14d792 DM	230	* @bdev: blockdev to issue
	231	* @sector: start sector
	232	* @nr_sects: number of sectors to write
	233	* @gfp_mask: memory allocation flags (for bio_alloc)
e73c23ff	234	* @biop: pointer to anchor bio
ee472d83	235	* @flags: controls detailed behavior
3f14d792 DM	236	*
3f14d792 DM	237	* Description:
ee472d83 CH	238	* Zero-fill a block range, either using hardware offload or by explicitly
	239	* writing zeroes to the device.
	240	*
	241	* If a device is using logical block provisioning, the underlying space will
	242	* not be released if %flags contains BLKDEV_ZERO_NOUNMAP.
cb365b96 CH	243	*
	244	* If %flags contains BLKDEV_ZERO_NOFALLBACK, the function will return
	245	* -EOPNOTSUPP if no explicit hardware offload for zeroing is provided.
3f14d792	246	*/
e73c23ff CK	247	int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
e73c23ff CK	248	sector_t nr_sects, gfp_t gfp_mask, struct bio **biop,
ee472d83	249	unsigned flags)
3f14d792	250	{
18edc8ea	251	int ret;
28b2be20 DW	252	sector_t bs_mask;
	253
	254	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
	255	if ((sector \| nr_sects) & bs_mask)
	256	return -EINVAL;
3f14d792	257
a6f0788e	258	ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects, gfp_mask,
d928be9f	259	biop, flags);
cb365b96	260	if (ret != -EOPNOTSUPP \|\| (flags & BLKDEV_ZERO_NOFALLBACK))
425a4dba	261	return ret;
3f14d792	262
425a4dba ID	263	return __blkdev_issue_zero_pages(bdev, sector, nr_sects, gfp_mask,
425a4dba ID	264	biop);
3f14d792	265	}
e73c23ff	266	EXPORT_SYMBOL(__blkdev_issue_zeroout);
579e8f3c MP	267
	268	/**
	269	* blkdev_issue_zeroout - zero-fill a block range
	270	* @bdev: blockdev to write
	271	* @sector: start sector
	272	* @nr_sects: number of sectors to write
	273	* @gfp_mask: memory allocation flags (for bio_alloc)
ee472d83	274	* @flags: controls detailed behavior
579e8f3c MP	275	*
579e8f3c MP	276	* Description:
ee472d83 CH	277	* Zero-fill a block range, either using hardware offload or by explicitly
	278	* writing zeroes to the device. See __blkdev_issue_zeroout() for the
	279	* valid values for %flags.
579e8f3c	280	*/
579e8f3c	281	int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
ee472d83	282	sector_t nr_sects, gfp_t gfp_mask, unsigned flags)
579e8f3c	283	{
d5ce4c31 ID	284	int ret = 0;
	285	sector_t bs_mask;
	286	struct bio *bio;
e73c23ff	287	struct blk_plug plug;
d5ce4c31	288	bool try_write_zeroes = !!bdev_write_zeroes_sectors(bdev);
d93ba7a5	289
d5ce4c31 ID	290	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
	291	if ((sector \| nr_sects) & bs_mask)
	292	return -EINVAL;
	293
	294	retry:
	295	bio = NULL;
e73c23ff	296	blk_start_plug(&plug);
d5ce4c31 ID	297	if (try_write_zeroes) {
	298	ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects,
	299	gfp_mask, &bio, flags);
	300	} else if (!(flags & BLKDEV_ZERO_NOFALLBACK)) {
	301	ret = __blkdev_issue_zero_pages(bdev, sector, nr_sects,
	302	gfp_mask, &bio);
	303	} else {
	304	/* No zeroing offload support */
	305	ret = -EOPNOTSUPP;
	306	}
e73c23ff CK	307	if (ret == 0 && bio) {
	308	ret = submit_bio_wait(bio);
	309	bio_put(bio);
	310	}
	311	blk_finish_plug(&plug);
8a08c5fd	312	if (ret && ret != -EINTR && try_write_zeroes) {
d5ce4c31 ID	313	if (!(flags & BLKDEV_ZERO_NOFALLBACK)) {
	314	try_write_zeroes = false;
	315	goto retry;
	316	}
	317	if (!bdev_write_zeroes_sectors(bdev)) {
	318	/*
	319	* Zeroing offload support was indicated, but the
	320	* device reported ILLEGAL REQUEST (for some devices
	321	* there is no non-destructive way to verify whether
	322	* WRITE ZEROES is actually supported).
	323	*/
	324	ret = -EOPNOTSUPP;
	325	}
	326	}
579e8f3c	327
e73c23ff	328	return ret;
579e8f3c	329	}
3f14d792	330	EXPORT_SYMBOL(blkdev_issue_zeroout);
44abff2c CH	331
	332	int blkdev_issue_secure_erase(struct block_device *bdev, sector_t sector,
	333	sector_t nr_sects, gfp_t gfp)
	334	{
	335	sector_t bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
	336	unsigned int max_sectors = bdev_max_secure_erase_sectors(bdev);
	337	struct bio *bio = NULL;
	338	struct blk_plug plug;
	339	int ret = 0;
	340
c4fa3684 MP	341	/* make sure that "len << SECTOR_SHIFT" doesn't overflow */
	342	if (max_sectors > UINT_MAX >> SECTOR_SHIFT)
	343	max_sectors = UINT_MAX >> SECTOR_SHIFT;
	344	max_sectors &= ~bs_mask;
	345
44abff2c CH	346	if (max_sectors == 0)
	347	return -EOPNOTSUPP;
	348	if ((sector \| nr_sects) & bs_mask)
	349	return -EINVAL;
	350	if (bdev_read_only(bdev))
	351	return -EPERM;
	352
	353	blk_start_plug(&plug);
5affe497	354	while (nr_sects) {
44abff2c CH	355	unsigned int len = min_t(sector_t, nr_sects, max_sectors);
	356
	357	bio = blk_next_bio(bio, bdev, 0, REQ_OP_SECURE_ERASE, gfp);
	358	bio->bi_iter.bi_sector = sector;
c4fa3684	359	bio->bi_iter.bi_size = len << SECTOR_SHIFT;
44abff2c	360
c4fa3684 MP	361	sector += len;
c4fa3684 MP	362	nr_sects -= len;
44abff2c	363	cond_resched();
8a08c5fd KB	364	if (fatal_signal_pending(current)) {
	365	await_bio_chain(bio);
	366	ret = -EINTR;
	367	bio = NULL;
	368	break;
	369	}
44abff2c	370	}
5affe497 KB	371	if (bio) {
	372	ret = submit_bio_wait(bio);
	373	bio_put(bio);
	374	}
44abff2c CH	375	blk_finish_plug(&plug);
	376
	377	return ret;
	378	}
	379	EXPORT_SYMBOL(blkdev_issue_secure_erase);