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git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blob - block/blk-lib.c
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 struct bio
*next_bio(struct bio
*bio
, unsigned int nr_pages
,
16 struct bio
*new = bio_alloc(gfp
, nr_pages
);
26 int __blkdev_issue_discard(struct block_device
*bdev
, sector_t sector
,
27 sector_t nr_sects
, gfp_t gfp_mask
, int flags
,
30 struct request_queue
*q
= bdev_get_queue(bdev
);
31 struct bio
*bio
= *biop
;
38 if (flags
& BLKDEV_DISCARD_SECURE
) {
39 if (!blk_queue_secure_erase(q
))
41 op
= REQ_OP_SECURE_ERASE
;
43 if (!blk_queue_discard(q
))
48 bs_mask
= (bdev_logical_block_size(bdev
) >> 9) - 1;
49 if ((sector
| nr_sects
) & bs_mask
)
53 unsigned int req_sects
= nr_sects
;
56 req_sects
= min(req_sects
, bio_allowed_max_sectors(q
));
60 end_sect
= sector
+ req_sects
;
62 bio
= next_bio(bio
, 0, gfp_mask
);
63 bio
->bi_iter
.bi_sector
= sector
;
64 bio_set_dev(bio
, bdev
);
65 bio_set_op_attrs(bio
, op
, 0);
67 bio
->bi_iter
.bi_size
= req_sects
<< 9;
68 nr_sects
-= req_sects
;
72 * We can loop for a long time in here, if someone does
73 * full device discards (like mkfs). Be nice and allow
74 * us to schedule out to avoid softlocking if preempt
91 EXPORT_SYMBOL(__blkdev_issue_discard
);
94 * blkdev_issue_discard - queue a discard
95 * @bdev: blockdev to issue discard for
96 * @sector: start sector
97 * @nr_sects: number of sectors to discard
98 * @gfp_mask: memory allocation flags (for bio_alloc)
99 * @flags: BLKDEV_DISCARD_* flags to control behaviour
102 * Issue a discard request for the sectors in question.
104 int blkdev_issue_discard(struct block_device
*bdev
, sector_t sector
,
105 sector_t nr_sects
, gfp_t gfp_mask
, unsigned long flags
)
107 struct bio
*bio
= NULL
;
108 struct blk_plug plug
;
111 blk_start_plug(&plug
);
112 ret
= __blkdev_issue_discard(bdev
, sector
, nr_sects
, gfp_mask
, flags
,
115 ret
= submit_bio_wait(bio
);
116 if (ret
== -EOPNOTSUPP
)
120 blk_finish_plug(&plug
);
124 EXPORT_SYMBOL(blkdev_issue_discard
);
127 * __blkdev_issue_write_same - generate number of bios with same page
128 * @bdev: target blockdev
129 * @sector: start sector
130 * @nr_sects: number of sectors to write
131 * @gfp_mask: memory allocation flags (for bio_alloc)
132 * @page: page containing data to write
133 * @biop: pointer to anchor bio
136 * Generate and issue number of bios(REQ_OP_WRITE_SAME) with same page.
138 static int __blkdev_issue_write_same(struct block_device
*bdev
, sector_t sector
,
139 sector_t nr_sects
, gfp_t gfp_mask
, struct page
*page
,
142 struct request_queue
*q
= bdev_get_queue(bdev
);
143 unsigned int max_write_same_sectors
;
144 struct bio
*bio
= *biop
;
150 bs_mask
= (bdev_logical_block_size(bdev
) >> 9) - 1;
151 if ((sector
| nr_sects
) & bs_mask
)
154 if (!bdev_write_same(bdev
))
157 /* Ensure that max_write_same_sectors doesn't overflow bi_size */
158 max_write_same_sectors
= bio_allowed_max_sectors(q
);
161 bio
= next_bio(bio
, 1, gfp_mask
);
162 bio
->bi_iter
.bi_sector
= sector
;
163 bio_set_dev(bio
, bdev
);
165 bio
->bi_io_vec
->bv_page
= page
;
166 bio
->bi_io_vec
->bv_offset
= 0;
167 bio
->bi_io_vec
->bv_len
= bdev_logical_block_size(bdev
);
168 bio_set_op_attrs(bio
, REQ_OP_WRITE_SAME
, 0);
170 if (nr_sects
> max_write_same_sectors
) {
171 bio
->bi_iter
.bi_size
= max_write_same_sectors
<< 9;
172 nr_sects
-= max_write_same_sectors
;
173 sector
+= max_write_same_sectors
;
175 bio
->bi_iter
.bi_size
= nr_sects
<< 9;
186 * blkdev_issue_write_same - queue a write same operation
187 * @bdev: target blockdev
188 * @sector: start sector
189 * @nr_sects: number of sectors to write
190 * @gfp_mask: memory allocation flags (for bio_alloc)
191 * @page: page containing data
194 * Issue a write same request for the sectors in question.
196 int blkdev_issue_write_same(struct block_device
*bdev
, sector_t sector
,
197 sector_t nr_sects
, gfp_t gfp_mask
,
200 struct bio
*bio
= NULL
;
201 struct blk_plug plug
;
204 blk_start_plug(&plug
);
205 ret
= __blkdev_issue_write_same(bdev
, sector
, nr_sects
, gfp_mask
, page
,
207 if (ret
== 0 && bio
) {
208 ret
= submit_bio_wait(bio
);
211 blk_finish_plug(&plug
);
214 EXPORT_SYMBOL(blkdev_issue_write_same
);
216 static int __blkdev_issue_write_zeroes(struct block_device
*bdev
,
217 sector_t sector
, sector_t nr_sects
, gfp_t gfp_mask
,
218 struct bio
**biop
, unsigned flags
)
220 struct bio
*bio
= *biop
;
221 unsigned int max_write_zeroes_sectors
;
222 struct request_queue
*q
= bdev_get_queue(bdev
);
227 /* Ensure that max_write_zeroes_sectors doesn't overflow bi_size */
228 max_write_zeroes_sectors
= bdev_write_zeroes_sectors(bdev
);
230 if (max_write_zeroes_sectors
== 0)
234 bio
= next_bio(bio
, 0, gfp_mask
);
235 bio
->bi_iter
.bi_sector
= sector
;
236 bio_set_dev(bio
, bdev
);
237 bio
->bi_opf
= REQ_OP_WRITE_ZEROES
;
238 if (flags
& BLKDEV_ZERO_NOUNMAP
)
239 bio
->bi_opf
|= REQ_NOUNMAP
;
241 if (nr_sects
> max_write_zeroes_sectors
) {
242 bio
->bi_iter
.bi_size
= max_write_zeroes_sectors
<< 9;
243 nr_sects
-= max_write_zeroes_sectors
;
244 sector
+= max_write_zeroes_sectors
;
246 bio
->bi_iter
.bi_size
= nr_sects
<< 9;
257 * Convert a number of 512B sectors to a number of pages.
258 * The result is limited to a number of pages that can fit into a BIO.
259 * Also make sure that the result is always at least 1 (page) for the cases
260 * where nr_sects is lower than the number of sectors in a page.
262 static unsigned int __blkdev_sectors_to_bio_pages(sector_t nr_sects
)
264 sector_t pages
= DIV_ROUND_UP_SECTOR_T(nr_sects
, PAGE_SIZE
/ 512);
266 return min(pages
, (sector_t
)BIO_MAX_PAGES
);
269 static int __blkdev_issue_zero_pages(struct block_device
*bdev
,
270 sector_t sector
, sector_t nr_sects
, gfp_t gfp_mask
,
273 struct request_queue
*q
= bdev_get_queue(bdev
);
274 struct bio
*bio
= *biop
;
281 while (nr_sects
!= 0) {
282 bio
= next_bio(bio
, __blkdev_sectors_to_bio_pages(nr_sects
),
284 bio
->bi_iter
.bi_sector
= sector
;
285 bio_set_dev(bio
, bdev
);
286 bio_set_op_attrs(bio
, REQ_OP_WRITE
, 0);
288 while (nr_sects
!= 0) {
289 sz
= min((sector_t
) PAGE_SIZE
, nr_sects
<< 9);
290 bi_size
= bio_add_page(bio
, ZERO_PAGE(0), sz
, 0);
291 nr_sects
-= bi_size
>> 9;
292 sector
+= bi_size
>> 9;
304 * __blkdev_issue_zeroout - generate number of zero filed write bios
305 * @bdev: blockdev to issue
306 * @sector: start sector
307 * @nr_sects: number of sectors to write
308 * @gfp_mask: memory allocation flags (for bio_alloc)
309 * @biop: pointer to anchor bio
310 * @flags: controls detailed behavior
313 * Zero-fill a block range, either using hardware offload or by explicitly
314 * writing zeroes to the device.
316 * If a device is using logical block provisioning, the underlying space will
317 * not be released if %flags contains BLKDEV_ZERO_NOUNMAP.
319 * If %flags contains BLKDEV_ZERO_NOFALLBACK, the function will return
320 * -EOPNOTSUPP if no explicit hardware offload for zeroing is provided.
322 int __blkdev_issue_zeroout(struct block_device
*bdev
, sector_t sector
,
323 sector_t nr_sects
, gfp_t gfp_mask
, struct bio
**biop
,
329 bs_mask
= (bdev_logical_block_size(bdev
) >> 9) - 1;
330 if ((sector
| nr_sects
) & bs_mask
)
333 ret
= __blkdev_issue_write_zeroes(bdev
, sector
, nr_sects
, gfp_mask
,
335 if (ret
!= -EOPNOTSUPP
|| (flags
& BLKDEV_ZERO_NOFALLBACK
))
338 return __blkdev_issue_zero_pages(bdev
, sector
, nr_sects
, gfp_mask
,
341 EXPORT_SYMBOL(__blkdev_issue_zeroout
);
344 * blkdev_issue_zeroout - zero-fill a block range
345 * @bdev: blockdev to write
346 * @sector: start sector
347 * @nr_sects: number of sectors to write
348 * @gfp_mask: memory allocation flags (for bio_alloc)
349 * @flags: controls detailed behavior
352 * Zero-fill a block range, either using hardware offload or by explicitly
353 * writing zeroes to the device. See __blkdev_issue_zeroout() for the
354 * valid values for %flags.
356 int blkdev_issue_zeroout(struct block_device
*bdev
, sector_t sector
,
357 sector_t nr_sects
, gfp_t gfp_mask
, unsigned flags
)
362 struct blk_plug plug
;
363 bool try_write_zeroes
= !!bdev_write_zeroes_sectors(bdev
);
365 bs_mask
= (bdev_logical_block_size(bdev
) >> 9) - 1;
366 if ((sector
| nr_sects
) & bs_mask
)
371 blk_start_plug(&plug
);
372 if (try_write_zeroes
) {
373 ret
= __blkdev_issue_write_zeroes(bdev
, sector
, nr_sects
,
374 gfp_mask
, &bio
, flags
);
375 } else if (!(flags
& BLKDEV_ZERO_NOFALLBACK
)) {
376 ret
= __blkdev_issue_zero_pages(bdev
, sector
, nr_sects
,
379 /* No zeroing offload support */
382 if (ret
== 0 && bio
) {
383 ret
= submit_bio_wait(bio
);
386 blk_finish_plug(&plug
);
387 if (ret
&& try_write_zeroes
) {
388 if (!(flags
& BLKDEV_ZERO_NOFALLBACK
)) {
389 try_write_zeroes
= false;
392 if (!bdev_write_zeroes_sectors(bdev
)) {
394 * Zeroing offload support was indicated, but the
395 * device reported ILLEGAL REQUEST (for some devices
396 * there is no non-destructive way to verify whether
397 * WRITE ZEROES is actually supported).
405 EXPORT_SYMBOL(blkdev_issue_zeroout
);