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 int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
14 sector_t nr_sects, gfp_t gfp_mask, int flags,
17 struct request_queue *q = bdev_get_queue(bdev);
18 struct bio *bio = *biop;
20 sector_t bs_mask, part_offset = 0;
22 if (bdev_read_only(bdev))
25 if (flags & BLKDEV_DISCARD_SECURE) {
26 if (!blk_queue_secure_erase(q))
28 op = REQ_OP_SECURE_ERASE;
30 if (!blk_queue_discard(q))
35 /* In case the discard granularity isn't set by buggy device driver */
36 if (WARN_ON_ONCE(!q->limits.discard_granularity)) {
37 char dev_name[BDEVNAME_SIZE];
39 bdevname(bdev, dev_name);
40 pr_err_ratelimited("%s: Error: discard_granularity is 0.\n", dev_name);
44 bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
45 if ((sector | nr_sects) & bs_mask)
51 /* In case the discard request is in a partition */
52 if (bdev_is_partition(bdev))
53 part_offset = bdev->bd_start_sect;
56 sector_t granularity_aligned_lba, req_sects;
57 sector_t sector_mapped = sector + part_offset;
59 granularity_aligned_lba = round_up(sector_mapped,
60 q->limits.discard_granularity >> SECTOR_SHIFT);
63 * Check whether the discard bio starts at a discard_granularity
65 * - If no: set (granularity_aligned_lba - sector_mapped) to
66 * bi_size of the first split bio, then the second bio will
67 * start at a discard_granularity aligned LBA on the device.
68 * - If yes: use bio_aligned_discard_max_sectors() as the max
69 * possible bi_size of the first split bio. Then when this bio
70 * is split in device drive, the split ones are very probably
71 * to be aligned to discard_granularity of the device's queue.
73 if (granularity_aligned_lba == sector_mapped)
74 req_sects = min_t(sector_t, nr_sects,
75 bio_aligned_discard_max_sectors(q));
77 req_sects = min_t(sector_t, nr_sects,
78 granularity_aligned_lba - sector_mapped);
80 WARN_ON_ONCE((req_sects << 9) > UINT_MAX);
82 bio = blk_next_bio(bio, bdev, 0, op, gfp_mask);
83 bio->bi_iter.bi_sector = sector;
84 bio->bi_iter.bi_size = req_sects << 9;
86 nr_sects -= req_sects;
89 * We can loop for a long time in here, if someone does
90 * full device discards (like mkfs). Be nice and allow
91 * us to schedule out to avoid softlocking if preempt
100 EXPORT_SYMBOL(__blkdev_issue_discard);
103 * blkdev_issue_discard - queue a discard
104 * @bdev: blockdev to issue discard for
105 * @sector: start sector
106 * @nr_sects: number of sectors to discard
107 * @gfp_mask: memory allocation flags (for bio_alloc)
108 * @flags: BLKDEV_DISCARD_* flags to control behaviour
111 * Issue a discard request for the sectors in question.
113 int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
114 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags)
116 struct bio *bio = NULL;
117 struct blk_plug plug;
120 blk_start_plug(&plug);
121 ret = __blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask, flags,
124 ret = submit_bio_wait(bio);
125 if (ret == -EOPNOTSUPP)
129 blk_finish_plug(&plug);
133 EXPORT_SYMBOL(blkdev_issue_discard);
136 * __blkdev_issue_write_same - generate number of bios with same page
137 * @bdev: target blockdev
138 * @sector: start sector
139 * @nr_sects: number of sectors to write
140 * @gfp_mask: memory allocation flags (for bio_alloc)
141 * @page: page containing data to write
142 * @biop: pointer to anchor bio
145 * Generate and issue number of bios(REQ_OP_WRITE_SAME) with same page.
147 static int __blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
148 sector_t nr_sects, gfp_t gfp_mask, struct page *page,
151 struct request_queue *q = bdev_get_queue(bdev);
152 unsigned int max_write_same_sectors;
153 struct bio *bio = *biop;
156 if (bdev_read_only(bdev))
159 bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
160 if ((sector | nr_sects) & bs_mask)
163 if (!bdev_write_same(bdev))
166 /* Ensure that max_write_same_sectors doesn't overflow bi_size */
167 max_write_same_sectors = bio_allowed_max_sectors(q);
170 bio = blk_next_bio(bio, bdev, 1, REQ_OP_WRITE_SAME, gfp_mask);
171 bio->bi_iter.bi_sector = sector;
173 bio->bi_io_vec->bv_page = page;
174 bio->bi_io_vec->bv_offset = 0;
175 bio->bi_io_vec->bv_len = bdev_logical_block_size(bdev);
177 if (nr_sects > max_write_same_sectors) {
178 bio->bi_iter.bi_size = max_write_same_sectors << 9;
179 nr_sects -= max_write_same_sectors;
180 sector += max_write_same_sectors;
182 bio->bi_iter.bi_size = nr_sects << 9;
193 * blkdev_issue_write_same - queue a write same operation
194 * @bdev: target blockdev
195 * @sector: start sector
196 * @nr_sects: number of sectors to write
197 * @gfp_mask: memory allocation flags (for bio_alloc)
198 * @page: page containing data
201 * Issue a write same request for the sectors in question.
203 int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
204 sector_t nr_sects, gfp_t gfp_mask,
207 struct bio *bio = NULL;
208 struct blk_plug plug;
211 blk_start_plug(&plug);
212 ret = __blkdev_issue_write_same(bdev, sector, nr_sects, gfp_mask, page,
214 if (ret == 0 && bio) {
215 ret = submit_bio_wait(bio);
218 blk_finish_plug(&plug);
221 EXPORT_SYMBOL(blkdev_issue_write_same);
223 static int __blkdev_issue_write_zeroes(struct block_device *bdev,
224 sector_t sector, sector_t nr_sects, gfp_t gfp_mask,
225 struct bio **biop, unsigned flags)
227 struct bio *bio = *biop;
228 unsigned int max_write_zeroes_sectors;
230 if (bdev_read_only(bdev))
233 /* Ensure that max_write_zeroes_sectors doesn't overflow bi_size */
234 max_write_zeroes_sectors = bdev_write_zeroes_sectors(bdev);
236 if (max_write_zeroes_sectors == 0)
240 bio = blk_next_bio(bio, bdev, 0, REQ_OP_WRITE_ZEROES, gfp_mask);
241 bio->bi_iter.bi_sector = sector;
242 if (flags & BLKDEV_ZERO_NOUNMAP)
243 bio->bi_opf |= REQ_NOUNMAP;
245 if (nr_sects > max_write_zeroes_sectors) {
246 bio->bi_iter.bi_size = max_write_zeroes_sectors << 9;
247 nr_sects -= max_write_zeroes_sectors;
248 sector += max_write_zeroes_sectors;
250 bio->bi_iter.bi_size = nr_sects << 9;
261 * Convert a number of 512B sectors to a number of pages.
262 * The result is limited to a number of pages that can fit into a BIO.
263 * Also make sure that the result is always at least 1 (page) for the cases
264 * where nr_sects is lower than the number of sectors in a page.
266 static unsigned int __blkdev_sectors_to_bio_pages(sector_t nr_sects)
268 sector_t pages = DIV_ROUND_UP_SECTOR_T(nr_sects, PAGE_SIZE / 512);
270 return min(pages, (sector_t)BIO_MAX_VECS);
273 static int __blkdev_issue_zero_pages(struct block_device *bdev,
274 sector_t sector, sector_t nr_sects, gfp_t gfp_mask,
277 struct bio *bio = *biop;
281 if (bdev_read_only(bdev))
284 while (nr_sects != 0) {
285 bio = blk_next_bio(bio, bdev, __blkdev_sectors_to_bio_pages(nr_sects),
286 REQ_OP_WRITE, gfp_mask);
287 bio->bi_iter.bi_sector = sector;
289 while (nr_sects != 0) {
290 sz = min((sector_t) PAGE_SIZE, nr_sects << 9);
291 bi_size = bio_add_page(bio, ZERO_PAGE(0), sz, 0);
292 nr_sects -= bi_size >> 9;
293 sector += bi_size >> 9;
305 * __blkdev_issue_zeroout - generate number of zero filed write bios
306 * @bdev: blockdev to issue
307 * @sector: start sector
308 * @nr_sects: number of sectors to write
309 * @gfp_mask: memory allocation flags (for bio_alloc)
310 * @biop: pointer to anchor bio
311 * @flags: controls detailed behavior
314 * Zero-fill a block range, either using hardware offload or by explicitly
315 * writing zeroes to the device.
317 * If a device is using logical block provisioning, the underlying space will
318 * not be released if %flags contains BLKDEV_ZERO_NOUNMAP.
320 * If %flags contains BLKDEV_ZERO_NOFALLBACK, the function will return
321 * -EOPNOTSUPP if no explicit hardware offload for zeroing is provided.
323 int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
324 sector_t nr_sects, gfp_t gfp_mask, struct bio **biop,
330 bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
331 if ((sector | nr_sects) & bs_mask)
334 ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects, gfp_mask,
336 if (ret != -EOPNOTSUPP || (flags & BLKDEV_ZERO_NOFALLBACK))
339 return __blkdev_issue_zero_pages(bdev, sector, nr_sects, gfp_mask,
342 EXPORT_SYMBOL(__blkdev_issue_zeroout);
345 * blkdev_issue_zeroout - zero-fill a block range
346 * @bdev: blockdev to write
347 * @sector: start sector
348 * @nr_sects: number of sectors to write
349 * @gfp_mask: memory allocation flags (for bio_alloc)
350 * @flags: controls detailed behavior
353 * Zero-fill a block range, either using hardware offload or by explicitly
354 * writing zeroes to the device. See __blkdev_issue_zeroout() for the
355 * valid values for %flags.
357 int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
358 sector_t nr_sects, gfp_t gfp_mask, unsigned flags)
363 struct blk_plug plug;
364 bool try_write_zeroes = !!bdev_write_zeroes_sectors(bdev);
366 bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
367 if ((sector | nr_sects) & bs_mask)
372 blk_start_plug(&plug);
373 if (try_write_zeroes) {
374 ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects,
375 gfp_mask, &bio, flags);
376 } else if (!(flags & BLKDEV_ZERO_NOFALLBACK)) {
377 ret = __blkdev_issue_zero_pages(bdev, sector, nr_sects,
380 /* No zeroing offload support */
383 if (ret == 0 && bio) {
384 ret = submit_bio_wait(bio);
387 blk_finish_plug(&plug);
388 if (ret && try_write_zeroes) {
389 if (!(flags & BLKDEV_ZERO_NOFALLBACK)) {
390 try_write_zeroes = false;
393 if (!bdev_write_zeroes_sectors(bdev)) {
395 * Zeroing offload support was indicated, but the
396 * device reported ILLEGAL REQUEST (for some devices
397 * there is no non-destructive way to verify whether
398 * WRITE ZEROES is actually supported).
406 EXPORT_SYMBOL(blkdev_issue_zeroout);