1 // SPDX-License-Identifier: GPL-2.0
3 * Functions related to generic helpers functions
5 #include <linux/kernel.h>
6 #include <linux/module.h>
8 #include <linux/blkdev.h>
9 #include <linux/scatterlist.h>
13 static sector_t bio_discard_limit(struct block_device *bdev, sector_t sector)
15 unsigned int discard_granularity = bdev_discard_granularity(bdev);
16 sector_t granularity_aligned_sector;
18 if (bdev_is_partition(bdev))
19 sector += bdev->bd_start_sect;
21 granularity_aligned_sector =
22 round_up(sector, discard_granularity >> SECTOR_SHIFT);
25 * Make sure subsequent bios start aligned to the discard granularity if
26 * it needs to be split.
28 if (granularity_aligned_sector != sector)
29 return granularity_aligned_sector - sector;
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.
35 return round_down(UINT_MAX, discard_granularity) >> SECTOR_SHIFT;
38 int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
39 sector_t nr_sects, gfp_t gfp_mask, struct bio **biop)
41 struct bio *bio = *biop;
44 if (bdev_read_only(bdev))
46 if (!bdev_max_discard_sectors(bdev))
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",
56 bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
57 if ((sector | nr_sects) & bs_mask)
65 min(nr_sects, bio_discard_limit(bdev, sector));
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;
71 nr_sects -= req_sects;
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
85 EXPORT_SYMBOL(__blkdev_issue_discard);
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)
95 * Issue a discard request for the sectors in question.
97 int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
98 sector_t nr_sects, gfp_t gfp_mask)
100 struct bio *bio = NULL;
101 struct blk_plug plug;
104 blk_start_plug(&plug);
105 ret = __blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask, &bio);
107 ret = submit_bio_wait(bio);
108 if (ret == -EOPNOTSUPP)
112 blk_finish_plug(&plug);
116 EXPORT_SYMBOL(blkdev_issue_discard);
118 static 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)
122 struct bio *bio = *biop;
123 unsigned int max_sectors;
125 if (bdev_read_only(bdev))
128 /* Ensure that max_sectors doesn't overflow bi_size */
129 max_sectors = bdev_write_zeroes_sectors(bdev);
131 if (max_sectors == 0)
135 unsigned int len = min_t(sector_t, nr_sects, max_sectors);
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;
142 bio->bi_iter.bi_size = len << SECTOR_SHIFT;
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.
158 static unsigned int __blkdev_sectors_to_bio_pages(sector_t nr_sects)
160 sector_t pages = DIV_ROUND_UP_SECTOR_T(nr_sects, PAGE_SIZE / 512);
162 return min(pages, (sector_t)BIO_MAX_VECS);
165 static int __blkdev_issue_zero_pages(struct block_device *bdev,
166 sector_t sector, sector_t nr_sects, gfp_t gfp_mask,
169 struct bio *bio = *biop;
173 if (bdev_read_only(bdev))
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;
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;
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
206 * Zero-fill a block range, either using hardware offload or by explicitly
207 * writing zeroes to the device.
209 * If a device is using logical block provisioning, the underlying space will
210 * not be released if %flags contains BLKDEV_ZERO_NOUNMAP.
212 * If %flags contains BLKDEV_ZERO_NOFALLBACK, the function will return
213 * -EOPNOTSUPP if no explicit hardware offload for zeroing is provided.
215 int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
216 sector_t nr_sects, gfp_t gfp_mask, struct bio **biop,
222 bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
223 if ((sector | nr_sects) & bs_mask)
226 ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects, gfp_mask,
228 if (ret != -EOPNOTSUPP || (flags & BLKDEV_ZERO_NOFALLBACK))
231 return __blkdev_issue_zero_pages(bdev, sector, nr_sects, gfp_mask,
234 EXPORT_SYMBOL(__blkdev_issue_zeroout);
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
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.
249 int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
250 sector_t nr_sects, gfp_t gfp_mask, unsigned flags)
255 struct blk_plug plug;
256 bool try_write_zeroes = !!bdev_write_zeroes_sectors(bdev);
258 bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
259 if ((sector | nr_sects) & bs_mask)
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,
272 /* No zeroing offload support */
275 if (ret == 0 && bio) {
276 ret = submit_bio_wait(bio);
279 blk_finish_plug(&plug);
280 if (ret && try_write_zeroes) {
281 if (!(flags & BLKDEV_ZERO_NOFALLBACK)) {
282 try_write_zeroes = false;
285 if (!bdev_write_zeroes_sectors(bdev)) {
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).
298 EXPORT_SYMBOL(blkdev_issue_zeroout);
300 int blkdev_issue_secure_erase(struct block_device *bdev, sector_t sector,
301 sector_t nr_sects, gfp_t gfp)
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;
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;
314 if (max_sectors == 0)
316 if ((sector | nr_sects) & bs_mask)
318 if (bdev_read_only(bdev))
321 blk_start_plug(&plug);
323 unsigned int len = min_t(sector_t, nr_sects, max_sectors);
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;
334 ret = submit_bio_wait(bio);
337 blk_finish_plug(&plug);
341 EXPORT_SYMBOL(blkdev_issue_secure_erase);