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v5.4
  1// SPDX-License-Identifier: GPL-2.0
  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
 13struct bio *blk_next_bio(struct bio *bio, unsigned int nr_pages, gfp_t gfp)
 14{
 15	struct bio *new = bio_alloc(gfp, nr_pages);
 
 16
 17	if (bio) {
 18		bio_chain(bio, new);
 19		submit_bio(bio);
 20	}
 21
 22	return new;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 23}
 24
 25int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 26		sector_t nr_sects, gfp_t gfp_mask, int flags,
 27		struct bio **biop)
 28{
 29	struct request_queue *q = bdev_get_queue(bdev);
 30	struct bio *bio = *biop;
 31	unsigned int op;
 32	sector_t bs_mask;
 33
 34	if (!q)
 35		return -ENXIO;
 36
 37	if (bdev_read_only(bdev))
 38		return -EPERM;
 
 
 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	}
 49
 50	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
 51	if ((sector | nr_sects) & bs_mask)
 52		return -EINVAL;
 53
 54	if (!nr_sects)
 55		return -EINVAL;
 56
 57	while (nr_sects) {
 58		sector_t req_sects = min_t(sector_t, nr_sects,
 59				bio_allowed_max_sectors(q));
 60
 61		WARN_ON_ONCE((req_sects << 9) > UINT_MAX);
 62
 63		bio = blk_next_bio(bio, 0, gfp_mask);
 64		bio->bi_iter.bi_sector = sector;
 65		bio_set_dev(bio, bdev);
 66		bio_set_op_attrs(bio, op, 0);
 67
 68		bio->bi_iter.bi_size = req_sects << 9;
 69		sector += req_sects;
 70		nr_sects -= req_sects;
 71
 72		/*
 73		 * We can loop for a long time in here, if someone does
 74		 * full device discards (like mkfs). Be nice and allow
 75		 * us to schedule out to avoid softlocking if preempt
 76		 * is disabled.
 77		 */
 78		cond_resched();
 79	}
 80
 81	*biop = bio;
 82	return 0;
 83}
 84EXPORT_SYMBOL(__blkdev_issue_discard);
 85
 86/**
 87 * blkdev_issue_discard - queue a discard
 88 * @bdev:	blockdev to issue discard for
 89 * @sector:	start sector
 90 * @nr_sects:	number of sectors to discard
 91 * @gfp_mask:	memory allocation flags (for bio_alloc)
 92 * @flags:	BLKDEV_DISCARD_* flags to control behaviour
 93 *
 94 * Description:
 95 *    Issue a discard request for the sectors in question.
 96 */
 97int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 98		sector_t nr_sects, gfp_t gfp_mask, unsigned long flags)
 99{
100	struct bio *bio = NULL;
101	struct blk_plug plug;
102	int ret;
103
104	blk_start_plug(&plug);
105	ret = __blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask, flags,
106			&bio);
107	if (!ret && bio) {
108		ret = submit_bio_wait(bio);
109		if (ret == -EOPNOTSUPP)
110			ret = 0;
111		bio_put(bio);
112	}
113	blk_finish_plug(&plug);
114
115	return ret;
116}
117EXPORT_SYMBOL(blkdev_issue_discard);
118
119/**
120 * __blkdev_issue_write_same - generate number of bios with same page
121 * @bdev:	target blockdev
122 * @sector:	start sector
123 * @nr_sects:	number of sectors to write
124 * @gfp_mask:	memory allocation flags (for bio_alloc)
125 * @page:	page containing data to write
126 * @biop:	pointer to anchor bio
127 *
128 * Description:
129 *  Generate and issue number of bios(REQ_OP_WRITE_SAME) with same page.
130 */
131static int __blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
132		sector_t nr_sects, gfp_t gfp_mask, struct page *page,
133		struct bio **biop)
134{
135	struct request_queue *q = bdev_get_queue(bdev);
136	unsigned int max_write_same_sectors;
137	struct bio *bio = *biop;
138	sector_t bs_mask;
139
140	if (!q)
141		return -ENXIO;
142
143	if (bdev_read_only(bdev))
144		return -EPERM;
145
146	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
147	if ((sector | nr_sects) & bs_mask)
148		return -EINVAL;
149
150	if (!bdev_write_same(bdev))
151		return -EOPNOTSUPP;
152
153	/* Ensure that max_write_same_sectors doesn't overflow bi_size */
154	max_write_same_sectors = bio_allowed_max_sectors(q);
155
156	while (nr_sects) {
157		bio = blk_next_bio(bio, 1, gfp_mask);
158		bio->bi_iter.bi_sector = sector;
159		bio_set_dev(bio, bdev);
160		bio->bi_vcnt = 1;
161		bio->bi_io_vec->bv_page = page;
162		bio->bi_io_vec->bv_offset = 0;
163		bio->bi_io_vec->bv_len = bdev_logical_block_size(bdev);
164		bio_set_op_attrs(bio, REQ_OP_WRITE_SAME, 0);
165
166		if (nr_sects > max_write_same_sectors) {
167			bio->bi_iter.bi_size = max_write_same_sectors << 9;
168			nr_sects -= max_write_same_sectors;
169			sector += max_write_same_sectors;
170		} else {
171			bio->bi_iter.bi_size = nr_sects << 9;
172			nr_sects = 0;
173		}
174		cond_resched();
175	}
176
177	*biop = bio;
178	return 0;
179}
180
181/**
182 * blkdev_issue_write_same - queue a write same operation
183 * @bdev:	target blockdev
184 * @sector:	start sector
185 * @nr_sects:	number of sectors to write
186 * @gfp_mask:	memory allocation flags (for bio_alloc)
187 * @page:	page containing data
188 *
189 * Description:
190 *    Issue a write same request for the sectors in question.
191 */
192int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
193				sector_t nr_sects, gfp_t gfp_mask,
194				struct page *page)
195{
196	struct bio *bio = NULL;
197	struct blk_plug plug;
198	int ret;
199
200	blk_start_plug(&plug);
201	ret = __blkdev_issue_write_same(bdev, sector, nr_sects, gfp_mask, page,
202			&bio);
203	if (ret == 0 && bio) {
204		ret = submit_bio_wait(bio);
205		bio_put(bio);
206	}
207	blk_finish_plug(&plug);
208	return ret;
209}
210EXPORT_SYMBOL(blkdev_issue_write_same);
211
212static int __blkdev_issue_write_zeroes(struct block_device *bdev,
213		sector_t sector, sector_t nr_sects, gfp_t gfp_mask,
214		struct bio **biop, unsigned flags)
215{
216	struct bio *bio = *biop;
217	unsigned int max_write_zeroes_sectors;
218	struct request_queue *q = bdev_get_queue(bdev);
219
220	if (!q)
221		return -ENXIO;
222
223	if (bdev_read_only(bdev))
224		return -EPERM;
225
226	/* Ensure that max_write_zeroes_sectors doesn't overflow bi_size */
227	max_write_zeroes_sectors = bdev_write_zeroes_sectors(bdev);
228
229	if (max_write_zeroes_sectors == 0)
230		return -EOPNOTSUPP;
231
232	while (nr_sects) {
233		bio = blk_next_bio(bio, 0, gfp_mask);
 
 
234		bio->bi_iter.bi_sector = sector;
235		bio_set_dev(bio, bdev);
236		bio->bi_opf = REQ_OP_WRITE_ZEROES;
237		if (flags & BLKDEV_ZERO_NOUNMAP)
238			bio->bi_opf |= REQ_NOUNMAP;
239
240		if (nr_sects > max_write_zeroes_sectors) {
241			bio->bi_iter.bi_size = max_write_zeroes_sectors << 9;
242			nr_sects -= max_write_zeroes_sectors;
243			sector += max_write_zeroes_sectors;
244		} else {
245			bio->bi_iter.bi_size = nr_sects << 9;
246			nr_sects = 0;
247		}
248		cond_resched();
249	}
250
251	*biop = bio;
252	return 0;
253}
254
255/*
256 * Convert a number of 512B sectors to a number of pages.
257 * The result is limited to a number of pages that can fit into a BIO.
258 * Also make sure that the result is always at least 1 (page) for the cases
259 * where nr_sects is lower than the number of sectors in a page.
260 */
261static unsigned int __blkdev_sectors_to_bio_pages(sector_t nr_sects)
262{
263	sector_t pages = DIV_ROUND_UP_SECTOR_T(nr_sects, PAGE_SIZE / 512);
264
265	return min(pages, (sector_t)BIO_MAX_PAGES);
266}
267
268static int __blkdev_issue_zero_pages(struct block_device *bdev,
269		sector_t sector, sector_t nr_sects, gfp_t gfp_mask,
270		struct bio **biop)
271{
272	struct request_queue *q = bdev_get_queue(bdev);
273	struct bio *bio = *biop;
274	int bi_size = 0;
275	unsigned int sz;
276
277	if (!q)
278		return -ENXIO;
279
280	if (bdev_read_only(bdev))
281		return -EPERM;
282
283	while (nr_sects != 0) {
284		bio = blk_next_bio(bio, __blkdev_sectors_to_bio_pages(nr_sects),
285				   gfp_mask);
286		bio->bi_iter.bi_sector = sector;
287		bio_set_dev(bio, bdev);
288		bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
289
290		while (nr_sects != 0) {
291			sz = min((sector_t) PAGE_SIZE, nr_sects << 9);
292			bi_size = bio_add_page(bio, ZERO_PAGE(0), sz, 0);
293			nr_sects -= bi_size >> 9;
294			sector += bi_size >> 9;
295			if (bi_size < sz)
296				break;
297		}
298		cond_resched();
299	}
300
301	*biop = bio;
302	return 0;
303}
304
305/**
306 * __blkdev_issue_zeroout - generate number of zero filed write bios
307 * @bdev:	blockdev to issue
308 * @sector:	start sector
309 * @nr_sects:	number of sectors to write
310 * @gfp_mask:	memory allocation flags (for bio_alloc)
311 * @biop:	pointer to anchor bio
312 * @flags:	controls detailed behavior
313 *
314 * Description:
315 *  Zero-fill a block range, either using hardware offload or by explicitly
316 *  writing zeroes to the device.
317 *
318 *  If a device is using logical block provisioning, the underlying space will
319 *  not be released if %flags contains BLKDEV_ZERO_NOUNMAP.
320 *
321 *  If %flags contains BLKDEV_ZERO_NOFALLBACK, the function will return
322 *  -EOPNOTSUPP if no explicit hardware offload for zeroing is provided.
323 */
324int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
325		sector_t nr_sects, gfp_t gfp_mask, struct bio **biop,
326		unsigned flags)
327{
328	int ret;
329	sector_t bs_mask;
330
331	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
332	if ((sector | nr_sects) & bs_mask)
333		return -EINVAL;
334
335	ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects, gfp_mask,
336			biop, flags);
337	if (ret != -EOPNOTSUPP || (flags & BLKDEV_ZERO_NOFALLBACK))
338		return ret;
339
340	return __blkdev_issue_zero_pages(bdev, sector, nr_sects, gfp_mask,
341					 biop);
342}
343EXPORT_SYMBOL(__blkdev_issue_zeroout);
344
345/**
346 * blkdev_issue_zeroout - zero-fill a block range
347 * @bdev:	blockdev to write
348 * @sector:	start sector
349 * @nr_sects:	number of sectors to write
350 * @gfp_mask:	memory allocation flags (for bio_alloc)
351 * @flags:	controls detailed behavior
352 *
353 * Description:
354 *  Zero-fill a block range, either using hardware offload or by explicitly
355 *  writing zeroes to the device.  See __blkdev_issue_zeroout() for the
356 *  valid values for %flags.
357 */
358int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
359		sector_t nr_sects, gfp_t gfp_mask, unsigned flags)
360{
361	int ret = 0;
362	sector_t bs_mask;
363	struct bio *bio;
364	struct blk_plug plug;
365	bool try_write_zeroes = !!bdev_write_zeroes_sectors(bdev);
366
367	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
368	if ((sector | nr_sects) & bs_mask)
369		return -EINVAL;
370
371retry:
372	bio = NULL;
373	blk_start_plug(&plug);
374	if (try_write_zeroes) {
375		ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects,
376						  gfp_mask, &bio, flags);
377	} else if (!(flags & BLKDEV_ZERO_NOFALLBACK)) {
378		ret = __blkdev_issue_zero_pages(bdev, sector, nr_sects,
379						gfp_mask, &bio);
380	} else {
381		/* No zeroing offload support */
382		ret = -EOPNOTSUPP;
383	}
384	if (ret == 0 && bio) {
385		ret = submit_bio_wait(bio);
386		bio_put(bio);
387	}
388	blk_finish_plug(&plug);
389	if (ret && try_write_zeroes) {
390		if (!(flags & BLKDEV_ZERO_NOFALLBACK)) {
391			try_write_zeroes = false;
392			goto retry;
393		}
394		if (!bdev_write_zeroes_sectors(bdev)) {
395			/*
396			 * Zeroing offload support was indicated, but the
397			 * device reported ILLEGAL REQUEST (for some devices
398			 * there is no non-destructive way to verify whether
399			 * WRITE ZEROES is actually supported).
400			 */
401			ret = -EOPNOTSUPP;
402		}
403	}
404
405	return ret;
406}
407EXPORT_SYMBOL(blkdev_issue_zeroout);
v6.9.4
  1// SPDX-License-Identifier: GPL-2.0
  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
 13static sector_t bio_discard_limit(struct block_device *bdev, sector_t sector)
 14{
 15	unsigned int discard_granularity = bdev_discard_granularity(bdev);
 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
 38int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 39		sector_t nr_sects, gfp_t gfp_mask, struct bio **biop)
 
 40{
 
 41	struct bio *bio = *biop;
 
 42	sector_t bs_mask;
 43
 
 
 
 44	if (bdev_read_only(bdev))
 45		return -EPERM;
 46	if (!bdev_max_discard_sectors(bdev))
 47		return -EOPNOTSUPP;
 48
 49	/* In case the discard granularity isn't set by buggy device driver */
 50	if (WARN_ON_ONCE(!bdev_discard_granularity(bdev))) {
 51		pr_err_ratelimited("%pg: Error: discard_granularity is 0.\n",
 52				   bdev);
 53		return -EOPNOTSUPP;
 
 
 
 54	}
 55
 56	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
 57	if ((sector | nr_sects) & bs_mask)
 58		return -EINVAL;
 59
 60	if (!nr_sects)
 61		return -EINVAL;
 62
 63	while (nr_sects) {
 64		sector_t req_sects =
 65			min(nr_sects, bio_discard_limit(bdev, sector));
 
 
 66
 67		bio = blk_next_bio(bio, bdev, 0, REQ_OP_DISCARD, gfp_mask);
 68		bio->bi_iter.bi_sector = sector;
 
 
 
 69		bio->bi_iter.bi_size = req_sects << 9;
 70		sector += req_sects;
 71		nr_sects -= req_sects;
 72
 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();
 80	}
 81
 82	*biop = bio;
 83	return 0;
 84}
 85EXPORT_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)
 
 93 *
 94 * Description:
 95 *    Issue a discard request for the sectors in question.
 96 */
 97int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 98		sector_t nr_sects, gfp_t gfp_mask)
 99{
100	struct bio *bio = NULL;
101	struct blk_plug plug;
102	int ret;
103
104	blk_start_plug(&plug);
105	ret = __blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask, &bio);
 
106	if (!ret && bio) {
107		ret = submit_bio_wait(bio);
108		if (ret == -EOPNOTSUPP)
109			ret = 0;
110		bio_put(bio);
111	}
112	blk_finish_plug(&plug);
113
114	return ret;
115}
116EXPORT_SYMBOL(blkdev_issue_discard);
117
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
118static int __blkdev_issue_write_zeroes(struct block_device *bdev,
119		sector_t sector, sector_t nr_sects, gfp_t gfp_mask,
120		struct bio **biop, unsigned flags)
121{
122	struct bio *bio = *biop;
123	unsigned int max_sectors;
 
 
 
 
124
125	if (bdev_read_only(bdev))
126		return -EPERM;
127
128	/* Ensure that max_sectors doesn't overflow bi_size */
129	max_sectors = bdev_write_zeroes_sectors(bdev);
130
131	if (max_sectors == 0)
132		return -EOPNOTSUPP;
133
134	while (nr_sects) {
135		unsigned int len = min_t(sector_t, nr_sects, max_sectors);
136
137		bio = blk_next_bio(bio, bdev, 0, REQ_OP_WRITE_ZEROES, gfp_mask);
138		bio->bi_iter.bi_sector = sector;
 
 
139		if (flags & BLKDEV_ZERO_NOUNMAP)
140			bio->bi_opf |= REQ_NOUNMAP;
141
142		bio->bi_iter.bi_size = len << SECTOR_SHIFT;
143		nr_sects -= len;
144		sector += len;
 
 
 
 
 
145		cond_resched();
146	}
147
148	*biop = bio;
149	return 0;
150}
151
152/*
153 * Convert a number of 512B sectors to a number of pages.
154 * The result is limited to a number of pages that can fit into a BIO.
155 * Also make sure that the result is always at least 1 (page) for the cases
156 * where nr_sects is lower than the number of sectors in a page.
157 */
158static unsigned int __blkdev_sectors_to_bio_pages(sector_t nr_sects)
159{
160	sector_t pages = DIV_ROUND_UP_SECTOR_T(nr_sects, PAGE_SIZE / 512);
161
162	return min(pages, (sector_t)BIO_MAX_VECS);
163}
164
165static int __blkdev_issue_zero_pages(struct block_device *bdev,
166		sector_t sector, sector_t nr_sects, gfp_t gfp_mask,
167		struct bio **biop)
168{
 
169	struct bio *bio = *biop;
170	int bi_size = 0;
171	unsigned int sz;
172
 
 
 
173	if (bdev_read_only(bdev))
174		return -EPERM;
175
176	while (nr_sects != 0) {
177		bio = blk_next_bio(bio, bdev, __blkdev_sectors_to_bio_pages(nr_sects),
178				   REQ_OP_WRITE, gfp_mask);
179		bio->bi_iter.bi_sector = sector;
 
 
180
181		while (nr_sects != 0) {
182			sz = min((sector_t) PAGE_SIZE, nr_sects << 9);
183			bi_size = bio_add_page(bio, ZERO_PAGE(0), sz, 0);
184			nr_sects -= bi_size >> 9;
185			sector += bi_size >> 9;
186			if (bi_size < sz)
187				break;
188		}
189		cond_resched();
190	}
191
192	*biop = bio;
193	return 0;
194}
195
196/**
197 * __blkdev_issue_zeroout - generate number of zero filed write bios
198 * @bdev:	blockdev to issue
199 * @sector:	start sector
200 * @nr_sects:	number of sectors to write
201 * @gfp_mask:	memory allocation flags (for bio_alloc)
202 * @biop:	pointer to anchor bio
203 * @flags:	controls detailed behavior
204 *
205 * Description:
206 *  Zero-fill a block range, either using hardware offload or by explicitly
207 *  writing zeroes to the device.
208 *
209 *  If a device is using logical block provisioning, the underlying space will
210 *  not be released if %flags contains BLKDEV_ZERO_NOUNMAP.
211 *
212 *  If %flags contains BLKDEV_ZERO_NOFALLBACK, the function will return
213 *  -EOPNOTSUPP if no explicit hardware offload for zeroing is provided.
214 */
215int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
216		sector_t nr_sects, gfp_t gfp_mask, struct bio **biop,
217		unsigned flags)
218{
219	int ret;
220	sector_t bs_mask;
221
222	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
223	if ((sector | nr_sects) & bs_mask)
224		return -EINVAL;
225
226	ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects, gfp_mask,
227			biop, flags);
228	if (ret != -EOPNOTSUPP || (flags & BLKDEV_ZERO_NOFALLBACK))
229		return ret;
230
231	return __blkdev_issue_zero_pages(bdev, sector, nr_sects, gfp_mask,
232					 biop);
233}
234EXPORT_SYMBOL(__blkdev_issue_zeroout);
235
236/**
237 * blkdev_issue_zeroout - zero-fill a block range
238 * @bdev:	blockdev to write
239 * @sector:	start sector
240 * @nr_sects:	number of sectors to write
241 * @gfp_mask:	memory allocation flags (for bio_alloc)
242 * @flags:	controls detailed behavior
243 *
244 * Description:
245 *  Zero-fill a block range, either using hardware offload or by explicitly
246 *  writing zeroes to the device.  See __blkdev_issue_zeroout() for the
247 *  valid values for %flags.
248 */
249int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
250		sector_t nr_sects, gfp_t gfp_mask, unsigned flags)
251{
252	int ret = 0;
253	sector_t bs_mask;
254	struct bio *bio;
255	struct blk_plug plug;
256	bool try_write_zeroes = !!bdev_write_zeroes_sectors(bdev);
257
258	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
259	if ((sector | nr_sects) & bs_mask)
260		return -EINVAL;
261
262retry:
263	bio = NULL;
264	blk_start_plug(&plug);
265	if (try_write_zeroes) {
266		ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects,
267						  gfp_mask, &bio, flags);
268	} else if (!(flags & BLKDEV_ZERO_NOFALLBACK)) {
269		ret = __blkdev_issue_zero_pages(bdev, sector, nr_sects,
270						gfp_mask, &bio);
271	} else {
272		/* No zeroing offload support */
273		ret = -EOPNOTSUPP;
274	}
275	if (ret == 0 && bio) {
276		ret = submit_bio_wait(bio);
277		bio_put(bio);
278	}
279	blk_finish_plug(&plug);
280	if (ret && try_write_zeroes) {
281		if (!(flags & BLKDEV_ZERO_NOFALLBACK)) {
282			try_write_zeroes = false;
283			goto retry;
284		}
285		if (!bdev_write_zeroes_sectors(bdev)) {
286			/*
287			 * Zeroing offload support was indicated, but the
288			 * device reported ILLEGAL REQUEST (for some devices
289			 * there is no non-destructive way to verify whether
290			 * WRITE ZEROES is actually supported).
291			 */
292			ret = -EOPNOTSUPP;
293		}
294	}
295
296	return ret;
297}
298EXPORT_SYMBOL(blkdev_issue_zeroout);
299
300int blkdev_issue_secure_erase(struct block_device *bdev, sector_t sector,
301		sector_t nr_sects, gfp_t gfp)
302{
303	sector_t bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
304	unsigned int max_sectors = bdev_max_secure_erase_sectors(bdev);
305	struct bio *bio = NULL;
306	struct blk_plug plug;
307	int ret = 0;
308
309	/* make sure that "len << SECTOR_SHIFT" doesn't overflow */
310	if (max_sectors > UINT_MAX >> SECTOR_SHIFT)
311		max_sectors = UINT_MAX >> SECTOR_SHIFT;
312	max_sectors &= ~bs_mask;
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	while (nr_sects) {
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 << SECTOR_SHIFT;
328
329		sector += len;
330		nr_sects -= len;
331		cond_resched();
332	}
333	if (bio) {
334		ret = submit_bio_wait(bio);
335		bio_put(bio);
336	}
337	blk_finish_plug(&plug);
338
339	return ret;
340}
341EXPORT_SYMBOL(blkdev_issue_secure_erase);