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1/*
2 * Functions related to generic helpers functions
3 */
4#include <linux/kernel.h>
5#include <linux/module.h>
6#include <linux/bio.h>
7#include <linux/blkdev.h>
8#include <linux/scatterlist.h>
9
10#include "blk.h"
11
12struct bio_batch {
13 atomic_t done;
14 unsigned long flags;
15 struct completion *wait;
16};
17
18static void bio_batch_end_io(struct bio *bio, int err)
19{
20 struct bio_batch *bb = bio->bi_private;
21
22 if (err && (err != -EOPNOTSUPP))
23 clear_bit(BIO_UPTODATE, &bb->flags);
24 if (atomic_dec_and_test(&bb->done))
25 complete(bb->wait);
26 bio_put(bio);
27}
28
29/**
30 * blkdev_issue_discard - queue a discard
31 * @bdev: blockdev to issue discard for
32 * @sector: start sector
33 * @nr_sects: number of sectors to discard
34 * @gfp_mask: memory allocation flags (for bio_alloc)
35 * @flags: BLKDEV_IFL_* flags to control behaviour
36 *
37 * Description:
38 * Issue a discard request for the sectors in question.
39 */
40int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
41 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags)
42{
43 DECLARE_COMPLETION_ONSTACK(wait);
44 struct request_queue *q = bdev_get_queue(bdev);
45 int type = REQ_WRITE | REQ_DISCARD;
46 unsigned int max_discard_sectors;
47 struct bio_batch bb;
48 struct bio *bio;
49 int ret = 0;
50
51 if (!q)
52 return -ENXIO;
53
54 if (!blk_queue_discard(q))
55 return -EOPNOTSUPP;
56
57 /*
58 * Ensure that max_discard_sectors is of the proper
59 * granularity
60 */
61 max_discard_sectors = min(q->limits.max_discard_sectors, UINT_MAX >> 9);
62 if (unlikely(!max_discard_sectors)) {
63 /* Avoid infinite loop below. Being cautious never hurts. */
64 return -EOPNOTSUPP;
65 } else if (q->limits.discard_granularity) {
66 unsigned int disc_sects = q->limits.discard_granularity >> 9;
67
68 max_discard_sectors &= ~(disc_sects - 1);
69 }
70
71 if (flags & BLKDEV_DISCARD_SECURE) {
72 if (!blk_queue_secdiscard(q))
73 return -EOPNOTSUPP;
74 type |= REQ_SECURE;
75 }
76
77 atomic_set(&bb.done, 1);
78 bb.flags = 1 << BIO_UPTODATE;
79 bb.wait = &wait;
80
81 while (nr_sects) {
82 bio = bio_alloc(gfp_mask, 1);
83 if (!bio) {
84 ret = -ENOMEM;
85 break;
86 }
87
88 bio->bi_sector = sector;
89 bio->bi_end_io = bio_batch_end_io;
90 bio->bi_bdev = bdev;
91 bio->bi_private = &bb;
92
93 if (nr_sects > max_discard_sectors) {
94 bio->bi_size = max_discard_sectors << 9;
95 nr_sects -= max_discard_sectors;
96 sector += max_discard_sectors;
97 } else {
98 bio->bi_size = nr_sects << 9;
99 nr_sects = 0;
100 }
101
102 atomic_inc(&bb.done);
103 submit_bio(type, bio);
104 }
105
106 /* Wait for bios in-flight */
107 if (!atomic_dec_and_test(&bb.done))
108 wait_for_completion(&wait);
109
110 if (!test_bit(BIO_UPTODATE, &bb.flags))
111 ret = -EIO;
112
113 return ret;
114}
115EXPORT_SYMBOL(blkdev_issue_discard);
116
117/**
118 * blkdev_issue_zeroout - generate number of zero filed write bios
119 * @bdev: blockdev to issue
120 * @sector: start sector
121 * @nr_sects: number of sectors to write
122 * @gfp_mask: memory allocation flags (for bio_alloc)
123 *
124 * Description:
125 * Generate and issue number of bios with zerofiled pages.
126 */
127
128int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
129 sector_t nr_sects, gfp_t gfp_mask)
130{
131 int ret;
132 struct bio *bio;
133 struct bio_batch bb;
134 unsigned int sz;
135 DECLARE_COMPLETION_ONSTACK(wait);
136
137 atomic_set(&bb.done, 1);
138 bb.flags = 1 << BIO_UPTODATE;
139 bb.wait = &wait;
140
141 ret = 0;
142 while (nr_sects != 0) {
143 bio = bio_alloc(gfp_mask,
144 min(nr_sects, (sector_t)BIO_MAX_PAGES));
145 if (!bio) {
146 ret = -ENOMEM;
147 break;
148 }
149
150 bio->bi_sector = sector;
151 bio->bi_bdev = bdev;
152 bio->bi_end_io = bio_batch_end_io;
153 bio->bi_private = &bb;
154
155 while (nr_sects != 0) {
156 sz = min((sector_t) PAGE_SIZE >> 9 , nr_sects);
157 ret = bio_add_page(bio, ZERO_PAGE(0), sz << 9, 0);
158 nr_sects -= ret >> 9;
159 sector += ret >> 9;
160 if (ret < (sz << 9))
161 break;
162 }
163 ret = 0;
164 atomic_inc(&bb.done);
165 submit_bio(WRITE, bio);
166 }
167
168 /* Wait for bios in-flight */
169 if (!atomic_dec_and_test(&bb.done))
170 wait_for_completion(&wait);
171
172 if (!test_bit(BIO_UPTODATE, &bb.flags))
173 /* One of bios in the batch was completed with error.*/
174 ret = -EIO;
175
176 return ret;
177}
178EXPORT_SYMBOL(blkdev_issue_zeroout);
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Functions related to generic helpers functions
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
13static sector_t bio_discard_limit(struct block_device *bdev, sector_t sector)
14{
15 unsigned int discard_granularity = bdev_discard_granularity(bdev);
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_granularity >> SECTOR_SHIFT);
23
24 /*
25 * Make sure subsequent bios start aligned to the discard granularity if
26 * it needs to be split.
27 */
28 if (granularity_aligned_sector != sector)
29 return granularity_aligned_sector - sector;
30
31 /*
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.
34 */
35 return round_down(UINT_MAX, discard_granularity) >> SECTOR_SHIFT;
36}
37
38int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
39 sector_t nr_sects, gfp_t gfp_mask, struct bio **biop)
40{
41 struct bio *bio = *biop;
42 sector_t bs_mask;
43
44 if (bdev_read_only(bdev))
45 return -EPERM;
46 if (!bdev_max_discard_sectors(bdev))
47 return -EOPNOTSUPP;
48
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",
52 bdev);
53 return -EOPNOTSUPP;
54 }
55
56 bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
57 if ((sector | nr_sects) & bs_mask)
58 return -EINVAL;
59
60 if (!nr_sects)
61 return -EINVAL;
62
63 while (nr_sects) {
64 sector_t req_sects =
65 min(nr_sects, bio_discard_limit(bdev, sector));
66
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;
70 sector += req_sects;
71 nr_sects -= req_sects;
72
73 /*
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
77 * is disabled.
78 */
79 cond_resched();
80 }
81
82 *biop = bio;
83 return 0;
84}
85EXPORT_SYMBOL(__blkdev_issue_discard);
86
87/**
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)
93 *
94 * Description:
95 * Issue a discard request for the sectors in question.
96 */
97int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
98 sector_t nr_sects, gfp_t gfp_mask)
99{
100 struct bio *bio = NULL;
101 struct blk_plug plug;
102 int ret;
103
104 blk_start_plug(&plug);
105 ret = __blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask, &bio);
106 if (!ret && bio) {
107 ret = submit_bio_wait(bio);
108 if (ret == -EOPNOTSUPP)
109 ret = 0;
110 bio_put(bio);
111 }
112 blk_finish_plug(&plug);
113
114 return ret;
115}
116EXPORT_SYMBOL(blkdev_issue_discard);
117
118static 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)
121{
122 struct bio *bio = *biop;
123 unsigned int max_sectors;
124
125 if (bdev_read_only(bdev))
126 return -EPERM;
127
128 /* Ensure that max_sectors doesn't overflow bi_size */
129 max_sectors = bdev_write_zeroes_sectors(bdev);
130
131 if (max_sectors == 0)
132 return -EOPNOTSUPP;
133
134 while (nr_sects) {
135 unsigned int len = min_t(sector_t, nr_sects, max_sectors);
136
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;
141
142 bio->bi_iter.bi_size = len << SECTOR_SHIFT;
143 nr_sects -= len;
144 sector += len;
145 cond_resched();
146 }
147
148 *biop = bio;
149 return 0;
150}
151
152/*
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.
157 */
158static unsigned int __blkdev_sectors_to_bio_pages(sector_t nr_sects)
159{
160 sector_t pages = DIV_ROUND_UP_SECTOR_T(nr_sects, PAGE_SIZE / 512);
161
162 return min(pages, (sector_t)BIO_MAX_VECS);
163}
164
165static int __blkdev_issue_zero_pages(struct block_device *bdev,
166 sector_t sector, sector_t nr_sects, gfp_t gfp_mask,
167 struct bio **biop)
168{
169 struct bio *bio = *biop;
170 int bi_size = 0;
171 unsigned int sz;
172
173 if (bdev_read_only(bdev))
174 return -EPERM;
175
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;
180
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;
186 if (bi_size < sz)
187 break;
188 }
189 cond_resched();
190 }
191
192 *biop = bio;
193 return 0;
194}
195
196/**
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
204 *
205 * Description:
206 * Zero-fill a block range, either using hardware offload or by explicitly
207 * writing zeroes to the device.
208 *
209 * If a device is using logical block provisioning, the underlying space will
210 * not be released if %flags contains BLKDEV_ZERO_NOUNMAP.
211 *
212 * If %flags contains BLKDEV_ZERO_NOFALLBACK, the function will return
213 * -EOPNOTSUPP if no explicit hardware offload for zeroing is provided.
214 */
215int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
216 sector_t nr_sects, gfp_t gfp_mask, struct bio **biop,
217 unsigned flags)
218{
219 int ret;
220 sector_t bs_mask;
221
222 bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
223 if ((sector | nr_sects) & bs_mask)
224 return -EINVAL;
225
226 ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects, gfp_mask,
227 biop, flags);
228 if (ret != -EOPNOTSUPP || (flags & BLKDEV_ZERO_NOFALLBACK))
229 return ret;
230
231 return __blkdev_issue_zero_pages(bdev, sector, nr_sects, gfp_mask,
232 biop);
233}
234EXPORT_SYMBOL(__blkdev_issue_zeroout);
235
236/**
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
243 *
244 * Description:
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.
248 */
249int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
250 sector_t nr_sects, gfp_t gfp_mask, unsigned flags)
251{
252 int ret = 0;
253 sector_t bs_mask;
254 struct bio *bio;
255 struct blk_plug plug;
256 bool try_write_zeroes = !!bdev_write_zeroes_sectors(bdev);
257
258 bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
259 if ((sector | nr_sects) & bs_mask)
260 return -EINVAL;
261
262retry:
263 bio = NULL;
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,
270 gfp_mask, &bio);
271 } else {
272 /* No zeroing offload support */
273 ret = -EOPNOTSUPP;
274 }
275 if (ret == 0 && bio) {
276 ret = submit_bio_wait(bio);
277 bio_put(bio);
278 }
279 blk_finish_plug(&plug);
280 if (ret && try_write_zeroes) {
281 if (!(flags & BLKDEV_ZERO_NOFALLBACK)) {
282 try_write_zeroes = false;
283 goto retry;
284 }
285 if (!bdev_write_zeroes_sectors(bdev)) {
286 /*
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).
291 */
292 ret = -EOPNOTSUPP;
293 }
294 }
295
296 return ret;
297}
298EXPORT_SYMBOL(blkdev_issue_zeroout);
299
300int blkdev_issue_secure_erase(struct block_device *bdev, sector_t sector,
301 sector_t nr_sects, gfp_t gfp)
302{
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;
307 int ret = 0;
308
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;
313
314 if (max_sectors == 0)
315 return -EOPNOTSUPP;
316 if ((sector | nr_sects) & bs_mask)
317 return -EINVAL;
318 if (bdev_read_only(bdev))
319 return -EPERM;
320
321 blk_start_plug(&plug);
322 while (nr_sects) {
323 unsigned int len = min_t(sector_t, nr_sects, max_sectors);
324
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;
328
329 sector += len;
330 nr_sects -= len;
331 cond_resched();
332 }
333 if (bio) {
334 ret = submit_bio_wait(bio);
335 bio_put(bio);
336 }
337 blk_finish_plug(&plug);
338
339 return ret;
340}
341EXPORT_SYMBOL(blkdev_issue_secure_erase);