2 * Functions related to generic helpers functions
4 #include <linux/kernel.h>
5 #include <linux/module.h>
7 #include <linux/blkdev.h>
8 #include <linux/scatterlist.h>
12 static struct bio *next_bio(struct bio *bio, unsigned int nr_pages,
15 struct bio *new = bio_alloc(gfp, nr_pages);
25 int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
26 sector_t nr_sects, gfp_t gfp_mask, int flags,
29 struct request_queue *q = bdev_get_queue(bdev);
30 struct bio *bio = *biop;
31 unsigned int granularity;
39 if (flags & BLKDEV_DISCARD_SECURE) {
40 if (flags & BLKDEV_DISCARD_ZERO)
42 if (!blk_queue_secure_erase(q))
44 op = REQ_OP_SECURE_ERASE;
46 if (!blk_queue_discard(q))
48 if ((flags & BLKDEV_DISCARD_ZERO) &&
49 !q->limits.discard_zeroes_data)
54 bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
55 if ((sector | nr_sects) & bs_mask)
58 /* Zero-sector (unknown) and one-sector granularities are the same. */
59 granularity = max(q->limits.discard_granularity >> 9, 1U);
60 alignment = (bdev_discard_alignment(bdev) >> 9) % granularity;
63 unsigned int req_sects;
64 sector_t end_sect, tmp;
66 /* Make sure bi_size doesn't overflow */
67 req_sects = min_t(sector_t, nr_sects, UINT_MAX >> 9);
70 * If splitting a request, and the next starting sector would be
71 * misaligned, stop the discard at the previous aligned sector.
73 end_sect = sector + req_sects;
75 if (req_sects < nr_sects &&
76 sector_div(tmp, granularity) != alignment) {
77 end_sect = end_sect - alignment;
78 sector_div(end_sect, granularity);
79 end_sect = end_sect * granularity + alignment;
80 req_sects = end_sect - sector;
83 bio = next_bio(bio, 0, gfp_mask);
84 bio->bi_iter.bi_sector = sector;
86 bio_set_op_attrs(bio, op, 0);
88 bio->bi_iter.bi_size = req_sects << 9;
89 nr_sects -= req_sects;
93 * We can loop for a long time in here, if someone does
94 * full device discards (like mkfs). Be nice and allow
95 * us to schedule out to avoid softlocking if preempt
104 EXPORT_SYMBOL(__blkdev_issue_discard);
107 * blkdev_issue_discard - queue a discard
108 * @bdev: blockdev to issue discard for
109 * @sector: start sector
110 * @nr_sects: number of sectors to discard
111 * @gfp_mask: memory allocation flags (for bio_alloc)
112 * @flags: BLKDEV_DISCARD_* flags to control behaviour
115 * Issue a discard request for the sectors in question.
117 int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
118 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags)
120 struct bio *bio = NULL;
121 struct blk_plug plug;
124 blk_start_plug(&plug);
125 ret = __blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask, flags,
128 ret = submit_bio_wait(bio);
129 if (ret == -EOPNOTSUPP && !(flags & BLKDEV_DISCARD_ZERO))
133 blk_finish_plug(&plug);
137 EXPORT_SYMBOL(blkdev_issue_discard);
140 * __blkdev_issue_write_same - generate number of bios with same page
141 * @bdev: target blockdev
142 * @sector: start sector
143 * @nr_sects: number of sectors to write
144 * @gfp_mask: memory allocation flags (for bio_alloc)
145 * @page: page containing data to write
146 * @biop: pointer to anchor bio
149 * Generate and issue number of bios(REQ_OP_WRITE_SAME) with same page.
151 static int __blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
152 sector_t nr_sects, gfp_t gfp_mask, struct page *page,
155 struct request_queue *q = bdev_get_queue(bdev);
156 unsigned int max_write_same_sectors;
157 struct bio *bio = *biop;
163 bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
164 if ((sector | nr_sects) & bs_mask)
167 if (!bdev_write_same(bdev))
170 /* Ensure that max_write_same_sectors doesn't overflow bi_size */
171 max_write_same_sectors = UINT_MAX >> 9;
174 bio = next_bio(bio, 1, gfp_mask);
175 bio->bi_iter.bi_sector = sector;
178 bio->bi_io_vec->bv_page = page;
179 bio->bi_io_vec->bv_offset = 0;
180 bio->bi_io_vec->bv_len = bdev_logical_block_size(bdev);
181 bio_set_op_attrs(bio, REQ_OP_WRITE_SAME, 0);
183 if (nr_sects > max_write_same_sectors) {
184 bio->bi_iter.bi_size = max_write_same_sectors << 9;
185 nr_sects -= max_write_same_sectors;
186 sector += max_write_same_sectors;
188 bio->bi_iter.bi_size = nr_sects << 9;
199 * blkdev_issue_write_same - queue a write same operation
200 * @bdev: target blockdev
201 * @sector: start sector
202 * @nr_sects: number of sectors to write
203 * @gfp_mask: memory allocation flags (for bio_alloc)
204 * @page: page containing data
207 * Issue a write same request for the sectors in question.
209 int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
210 sector_t nr_sects, gfp_t gfp_mask,
213 struct bio *bio = NULL;
214 struct blk_plug plug;
217 blk_start_plug(&plug);
218 ret = __blkdev_issue_write_same(bdev, sector, nr_sects, gfp_mask, page,
220 if (ret == 0 && bio) {
221 ret = submit_bio_wait(bio);
224 blk_finish_plug(&plug);
227 EXPORT_SYMBOL(blkdev_issue_write_same);
229 static int __blkdev_issue_write_zeroes(struct block_device *bdev,
230 sector_t sector, sector_t nr_sects, gfp_t gfp_mask,
231 struct bio **biop, unsigned flags)
233 struct bio *bio = *biop;
234 unsigned int max_write_zeroes_sectors;
235 struct request_queue *q = bdev_get_queue(bdev);
240 /* Ensure that max_write_zeroes_sectors doesn't overflow bi_size */
241 max_write_zeroes_sectors = bdev_write_zeroes_sectors(bdev);
243 if (max_write_zeroes_sectors == 0)
247 bio = next_bio(bio, 0, gfp_mask);
248 bio->bi_iter.bi_sector = sector;
250 bio->bi_opf = REQ_OP_WRITE_ZEROES;
251 if (flags & BLKDEV_ZERO_NOUNMAP)
252 bio->bi_opf |= REQ_NOUNMAP;
254 if (nr_sects > max_write_zeroes_sectors) {
255 bio->bi_iter.bi_size = max_write_zeroes_sectors << 9;
256 nr_sects -= max_write_zeroes_sectors;
257 sector += max_write_zeroes_sectors;
259 bio->bi_iter.bi_size = nr_sects << 9;
270 * __blkdev_issue_zeroout - generate number of zero filed write bios
271 * @bdev: blockdev to issue
272 * @sector: start sector
273 * @nr_sects: number of sectors to write
274 * @gfp_mask: memory allocation flags (for bio_alloc)
275 * @biop: pointer to anchor bio
276 * @flags: controls detailed behavior
279 * Zero-fill a block range, either using hardware offload or by explicitly
280 * writing zeroes to the device.
282 * If a device is using logical block provisioning, the underlying space will
283 * not be released if %flags contains BLKDEV_ZERO_NOUNMAP.
285 * If %flags contains BLKDEV_ZERO_NOFALLBACK, the function will return
286 * -EOPNOTSUPP if no explicit hardware offload for zeroing is provided.
288 int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
289 sector_t nr_sects, gfp_t gfp_mask, struct bio **biop,
294 struct bio *bio = *biop;
298 bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
299 if ((sector | nr_sects) & bs_mask)
302 ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects, gfp_mask,
304 if (ret != -EOPNOTSUPP || (flags & BLKDEV_ZERO_NOFALLBACK))
308 while (nr_sects != 0) {
309 bio = next_bio(bio, min(nr_sects, (sector_t)BIO_MAX_PAGES),
311 bio->bi_iter.bi_sector = sector;
313 bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
315 while (nr_sects != 0) {
316 sz = min((sector_t) PAGE_SIZE >> 9 , nr_sects);
317 bi_size = bio_add_page(bio, ZERO_PAGE(0), sz << 9, 0);
318 nr_sects -= bi_size >> 9;
319 sector += bi_size >> 9;
320 if (bi_size < (sz << 9))
330 EXPORT_SYMBOL(__blkdev_issue_zeroout);
333 * blkdev_issue_zeroout - zero-fill a block range
334 * @bdev: blockdev to write
335 * @sector: start sector
336 * @nr_sects: number of sectors to write
337 * @gfp_mask: memory allocation flags (for bio_alloc)
338 * @flags: controls detailed behavior
341 * Zero-fill a block range, either using hardware offload or by explicitly
342 * writing zeroes to the device. See __blkdev_issue_zeroout() for the
343 * valid values for %flags.
345 int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
346 sector_t nr_sects, gfp_t gfp_mask, unsigned flags)
349 struct bio *bio = NULL;
350 struct blk_plug plug;
352 if (!(flags & BLKDEV_ZERO_NOUNMAP)) {
353 if (!blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask,
354 BLKDEV_DISCARD_ZERO))
358 blk_start_plug(&plug);
359 ret = __blkdev_issue_zeroout(bdev, sector, nr_sects, gfp_mask,
361 if (ret == 0 && bio) {
362 ret = submit_bio_wait(bio);
365 blk_finish_plug(&plug);
369 EXPORT_SYMBOL(blkdev_issue_zeroout);