1 // SPDX-License-Identifier: GPL-2.0 1
2 /*
3 * Functions related to generic helpers functi
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
13 static sector_t bio_discard_limit(struct block
14 {
15 unsigned int discard_granularity = bde
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_granu
23
24 /*
25 * Make sure subsequent bios start ali
26 * it needs to be split.
27 */
28 if (granularity_aligned_sector != sect
29 return granularity_aligned_sec
30
31 /*
32 * Align the bio size to the discard g
33 * at discard granularity boundaries e
34 */
35 return round_down(UINT_MAX, discard_gr
36 }
37
38 struct bio *blk_alloc_discard_bio(struct block
39 sector_t *sector, sector_t *nr
40 {
41 sector_t bio_sects = min(*nr_sects, bi
42 struct bio *bio;
43
44 if (!bio_sects)
45 return NULL;
46
47 bio = bio_alloc(bdev, 0, REQ_OP_DISCAR
48 if (!bio)
49 return NULL;
50 bio->bi_iter.bi_sector = *sector;
51 bio->bi_iter.bi_size = bio_sects << SE
52 *sector += bio_sects;
53 *nr_sects -= bio_sects;
54 /*
55 * We can loop for a long time in here
56 * discards (like mkfs). Be nice and
57 * softlocking if preempt is disabled.
58 */
59 cond_resched();
60 return bio;
61 }
62
63 int __blkdev_issue_discard(struct block_device
64 sector_t nr_sects, gfp_t gfp_m
65 {
66 struct bio *bio;
67
68 while ((bio = blk_alloc_discard_bio(bd
69 gfp_mask)))
70 *biop = bio_chain_and_submit(*
71 return 0;
72 }
73 EXPORT_SYMBOL(__blkdev_issue_discard);
74
75 /**
76 * blkdev_issue_discard - queue a discard
77 * @bdev: blockdev to issue discard for
78 * @sector: start sector
79 * @nr_sects: number of sectors to discard
80 * @gfp_mask: memory allocation flags (for b
81 *
82 * Description:
83 * Issue a discard request for the sectors
84 */
85 int blkdev_issue_discard(struct block_device *
86 sector_t nr_sects, gfp_t gfp_m
87 {
88 struct bio *bio = NULL;
89 struct blk_plug plug;
90 int ret;
91
92 blk_start_plug(&plug);
93 ret = __blkdev_issue_discard(bdev, sec
94 if (!ret && bio) {
95 ret = submit_bio_wait(bio);
96 if (ret == -EOPNOTSUPP)
97 ret = 0;
98 bio_put(bio);
99 }
100 blk_finish_plug(&plug);
101
102 return ret;
103 }
104 EXPORT_SYMBOL(blkdev_issue_discard);
105
106 static sector_t bio_write_zeroes_limit(struct
107 {
108 sector_t bs_mask = (bdev_logical_block
109
110 return min(bdev_write_zeroes_sectors(b
111 (UINT_MAX >> SECTOR_SHIFT) & ~
112 }
113
114 /*
115 * There is no reliable way for the SCSI subsy
116 * device supports a WRITE SAME operation with
117 * to media. As a result, write_zeroes is enab
118 * disabled if a zeroing operation subsequentl
119 * queue limit is likely to change at runtime.
120 */
121 static void __blkdev_issue_write_zeroes(struct
122 sector_t sector, sector_t nr_s
123 struct bio **biop, unsigned fl
124 {
125
126 while (nr_sects) {
127 unsigned int len = min(nr_sect
128 struct bio *bio;
129
130 if ((flags & BLKDEV_ZERO_KILLA
131 fatal_signal_pending(curre
132 break;
133
134 bio = bio_alloc(bdev, 0, REQ_O
135 bio->bi_iter.bi_sector = secto
136 if (flags & BLKDEV_ZERO_NOUNMA
137 bio->bi_opf |= REQ_NOU
138
139 bio->bi_iter.bi_size = len <<
140 *biop = bio_chain_and_submit(*
141
142 nr_sects -= len;
143 sector += len;
144 cond_resched();
145 }
146 }
147
148 static int blkdev_issue_write_zeroes(struct bl
149 sector_t nr_sects, gfp_t gfp,
150 {
151 sector_t limit = bio_write_zeroes_limi
152 struct bio *bio = NULL;
153 struct blk_plug plug;
154 int ret = 0;
155
156 blk_start_plug(&plug);
157 __blkdev_issue_write_zeroes(bdev, sect
158 flags, limit);
159 if (bio) {
160 if ((flags & BLKDEV_ZERO_KILLA
161 fatal_signal_pending(curre
162 bio_await_chain(bio);
163 blk_finish_plug(&plug)
164 return -EINTR;
165 }
166 ret = submit_bio_wait(bio);
167 bio_put(bio);
168 }
169 blk_finish_plug(&plug);
170
171 /*
172 * For some devices there is no non-de
173 * WRITE ZEROES is actually supported.
174 * on an I/O error, in which case we'l
175 * "not supported" here.
176 */
177 if (ret && !bdev_write_zeroes_sectors(
178 return -EOPNOTSUPP;
179 return ret;
180 }
181
182 /*
183 * Convert a number of 512B sectors to a numbe
184 * The result is limited to a number of pages
185 * Also make sure that the result is always at
186 * where nr_sects is lower than the number of
187 */
188 static unsigned int __blkdev_sectors_to_bio_pa
189 {
190 sector_t pages = DIV_ROUND_UP_SECTOR_T
191
192 return min(pages, (sector_t)BIO_MAX_VE
193 }
194
195 static void __blkdev_issue_zero_pages(struct b
196 sector_t sector, sector_t nr_s
197 struct bio **biop, unsigned in
198 {
199 while (nr_sects) {
200 unsigned int nr_vecs = __blkde
201 struct bio *bio;
202
203 bio = bio_alloc(bdev, nr_vecs,
204 bio->bi_iter.bi_sector = secto
205
206 if ((flags & BLKDEV_ZERO_KILLA
207 fatal_signal_pending(curre
208 break;
209
210 do {
211 unsigned int len, adde
212
213 len = min_t(sector_t,
214 PAGE_SIZE, nr_
215 added = bio_add_page(b
216 if (added < len)
217 break;
218 nr_sects -= added >> S
219 sector += added >> SEC
220 } while (nr_sects);
221
222 *biop = bio_chain_and_submit(*
223 cond_resched();
224 }
225 }
226
227 static int blkdev_issue_zero_pages(struct bloc
228 sector_t nr_sects, gfp_t gfp,
229 {
230 struct bio *bio = NULL;
231 struct blk_plug plug;
232 int ret = 0;
233
234 if (flags & BLKDEV_ZERO_NOFALLBACK)
235 return -EOPNOTSUPP;
236
237 blk_start_plug(&plug);
238 __blkdev_issue_zero_pages(bdev, sector
239 if (bio) {
240 if ((flags & BLKDEV_ZERO_KILLA
241 fatal_signal_pending(curre
242 bio_await_chain(bio);
243 blk_finish_plug(&plug)
244 return -EINTR;
245 }
246 ret = submit_bio_wait(bio);
247 bio_put(bio);
248 }
249 blk_finish_plug(&plug);
250
251 return ret;
252 }
253
254 /**
255 * __blkdev_issue_zeroout - generate number of
256 * @bdev: blockdev to issue
257 * @sector: start sector
258 * @nr_sects: number of sectors to write
259 * @gfp_mask: memory allocation flags (for b
260 * @biop: pointer to anchor bio
261 * @flags: controls detailed behavior
262 *
263 * Description:
264 * Zero-fill a block range, either using hard
265 * writing zeroes to the device.
266 *
267 * If a device is using logical block provisi
268 * not be released if %flags contains BLKDEV_
269 *
270 * If %flags contains BLKDEV_ZERO_NOFALLBACK,
271 * -EOPNOTSUPP if no explicit hardware offloa
272 */
273 int __blkdev_issue_zeroout(struct block_device
274 sector_t nr_sects, gfp_t gfp_m
275 unsigned flags)
276 {
277 sector_t limit = bio_write_zeroes_limi
278
279 if (bdev_read_only(bdev))
280 return -EPERM;
281
282 if (limit) {
283 __blkdev_issue_write_zeroes(bd
284 gfp_mask, biop
285 } else {
286 if (flags & BLKDEV_ZERO_NOFALL
287 return -EOPNOTSUPP;
288 __blkdev_issue_zero_pages(bdev
289 biop, flags);
290 }
291 return 0;
292 }
293 EXPORT_SYMBOL(__blkdev_issue_zeroout);
294
295 /**
296 * blkdev_issue_zeroout - zero-fill a block ra
297 * @bdev: blockdev to write
298 * @sector: start sector
299 * @nr_sects: number of sectors to write
300 * @gfp_mask: memory allocation flags (for b
301 * @flags: controls detailed behavior
302 *
303 * Description:
304 * Zero-fill a block range, either using hard
305 * writing zeroes to the device. See __blkde
306 * valid values for %flags.
307 */
308 int blkdev_issue_zeroout(struct block_device *
309 sector_t nr_sects, gfp_t gfp_m
310 {
311 int ret;
312
313 if ((sector | nr_sects) & ((bdev_logic
314 return -EINVAL;
315 if (bdev_read_only(bdev))
316 return -EPERM;
317
318 if (bdev_write_zeroes_sectors(bdev)) {
319 ret = blkdev_issue_write_zeroe
320 gfp_mask, flag
321 if (ret != -EOPNOTSUPP)
322 return ret;
323 }
324
325 return blkdev_issue_zero_pages(bdev, s
326 }
327 EXPORT_SYMBOL(blkdev_issue_zeroout);
328
329 int blkdev_issue_secure_erase(struct block_dev
330 sector_t nr_sects, gfp_t gfp)
331 {
332 sector_t bs_mask = (bdev_logical_block
333 unsigned int max_sectors = bdev_max_se
334 struct bio *bio = NULL;
335 struct blk_plug plug;
336 int ret = 0;
337
338 /* make sure that "len << SECTOR_SHIFT
339 if (max_sectors > UINT_MAX >> SECTOR_S
340 max_sectors = UINT_MAX >> SECT
341 max_sectors &= ~bs_mask;
342
343 if (max_sectors == 0)
344 return -EOPNOTSUPP;
345 if ((sector | nr_sects) & bs_mask)
346 return -EINVAL;
347 if (bdev_read_only(bdev))
348 return -EPERM;
349
350 blk_start_plug(&plug);
351 while (nr_sects) {
352 unsigned int len = min_t(secto
353
354 bio = blk_next_bio(bio, bdev,
355 bio->bi_iter.bi_sector = secto
356 bio->bi_iter.bi_size = len <<
357
358 sector += len;
359 nr_sects -= len;
360 cond_resched();
361 }
362 if (bio) {
363 ret = submit_bio_wait(bio);
364 bio_put(bio);
365 }
366 blk_finish_plug(&plug);
367
368 return ret;
369 }
370 EXPORT_SYMBOL(blkdev_issue_secure_erase);
371
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.