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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
f31e7e40 DM |
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 | ||
38f25255 | 13 | int __blkdev_issue_discard(struct block_device *bdev, sector_t sector, |
288dab8a | 14 | sector_t nr_sects, gfp_t gfp_mask, int flags, |
469e3216 | 15 | struct bio **biop) |
f31e7e40 | 16 | { |
f31e7e40 | 17 | struct request_queue *q = bdev_get_queue(bdev); |
38f25255 | 18 | struct bio *bio = *biop; |
ef295ecf | 19 | unsigned int op; |
9b15d109 | 20 | sector_t bs_mask, part_offset = 0; |
f31e7e40 | 21 | |
a13553c7 ID |
22 | if (bdev_read_only(bdev)) |
23 | return -EPERM; | |
24 | ||
288dab8a CH |
25 | if (flags & BLKDEV_DISCARD_SECURE) { |
26 | if (!blk_queue_secure_erase(q)) | |
27 | return -EOPNOTSUPP; | |
28 | op = REQ_OP_SECURE_ERASE; | |
29 | } else { | |
30 | if (!blk_queue_discard(q)) | |
31 | return -EOPNOTSUPP; | |
32 | op = REQ_OP_DISCARD; | |
33 | } | |
f31e7e40 | 34 | |
b35fd742 CL |
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]; | |
38 | ||
39 | bdevname(bdev, dev_name); | |
40 | pr_err_ratelimited("%s: Error: discard_granularity is 0.\n", dev_name); | |
41 | return -EOPNOTSUPP; | |
42 | } | |
43 | ||
28b2be20 DW |
44 | bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1; |
45 | if ((sector | nr_sects) & bs_mask) | |
46 | return -EINVAL; | |
47 | ||
ba5d7385 ML |
48 | if (!nr_sects) |
49 | return -EINVAL; | |
a22c4d7e | 50 | |
9b15d109 | 51 | /* In case the discard request is in a partition */ |
fa01b1e9 | 52 | if (bdev_is_partition(bdev)) |
29ff57c6 | 53 | part_offset = bdev->bd_start_sect; |
9b15d109 | 54 | |
ba5d7385 | 55 | while (nr_sects) { |
9b15d109 CL |
56 | sector_t granularity_aligned_lba, req_sects; |
57 | sector_t sector_mapped = sector + part_offset; | |
58 | ||
59 | granularity_aligned_lba = round_up(sector_mapped, | |
60 | q->limits.discard_granularity >> SECTOR_SHIFT); | |
61 | ||
62 | /* | |
63 | * Check whether the discard bio starts at a discard_granularity | |
64 | * aligned LBA, | |
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. | |
72 | */ | |
73 | if (granularity_aligned_lba == sector_mapped) | |
74 | req_sects = min_t(sector_t, nr_sects, | |
75 | bio_aligned_discard_max_sectors(q)); | |
76 | else | |
77 | req_sects = min_t(sector_t, nr_sects, | |
78 | granularity_aligned_lba - sector_mapped); | |
c6e66634 | 79 | |
4800bf7b DC |
80 | WARN_ON_ONCE((req_sects << 9) > UINT_MAX); |
81 | ||
0a3140ea | 82 | bio = blk_next_bio(bio, bdev, 0, op, gfp_mask); |
4f024f37 | 83 | bio->bi_iter.bi_sector = sector; |
4f024f37 | 84 | bio->bi_iter.bi_size = req_sects << 9; |
ba5d7385 | 85 | sector += req_sects; |
c6e66634 | 86 | nr_sects -= req_sects; |
f31e7e40 | 87 | |
c8123f8c JA |
88 | /* |
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 | |
92 | * is disabled. | |
93 | */ | |
94 | cond_resched(); | |
5dba3089 | 95 | } |
38f25255 CH |
96 | |
97 | *biop = bio; | |
98 | return 0; | |
99 | } | |
100 | EXPORT_SYMBOL(__blkdev_issue_discard); | |
101 | ||
102 | /** | |
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) | |
e554911c | 108 | * @flags: BLKDEV_DISCARD_* flags to control behaviour |
38f25255 CH |
109 | * |
110 | * Description: | |
111 | * Issue a discard request for the sectors in question. | |
112 | */ | |
113 | int blkdev_issue_discard(struct block_device *bdev, sector_t sector, | |
114 | sector_t nr_sects, gfp_t gfp_mask, unsigned long flags) | |
115 | { | |
38f25255 CH |
116 | struct bio *bio = NULL; |
117 | struct blk_plug plug; | |
118 | int ret; | |
119 | ||
38f25255 | 120 | blk_start_plug(&plug); |
288dab8a | 121 | ret = __blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask, flags, |
38f25255 | 122 | &bio); |
bbd848e0 | 123 | if (!ret && bio) { |
4e49ea4a | 124 | ret = submit_bio_wait(bio); |
48920ff2 | 125 | if (ret == -EOPNOTSUPP) |
bbd848e0 | 126 | ret = 0; |
05bd92dd | 127 | bio_put(bio); |
bbd848e0 | 128 | } |
0cfbcafc | 129 | blk_finish_plug(&plug); |
f31e7e40 | 130 | |
bbd848e0 | 131 | return ret; |
f31e7e40 DM |
132 | } |
133 | EXPORT_SYMBOL(blkdev_issue_discard); | |
3f14d792 | 134 | |
a6f0788e CK |
135 | static int __blkdev_issue_write_zeroes(struct block_device *bdev, |
136 | sector_t sector, sector_t nr_sects, gfp_t gfp_mask, | |
d928be9f | 137 | struct bio **biop, unsigned flags) |
a6f0788e CK |
138 | { |
139 | struct bio *bio = *biop; | |
140 | unsigned int max_write_zeroes_sectors; | |
a6f0788e | 141 | |
a13553c7 ID |
142 | if (bdev_read_only(bdev)) |
143 | return -EPERM; | |
144 | ||
a6f0788e CK |
145 | /* Ensure that max_write_zeroes_sectors doesn't overflow bi_size */ |
146 | max_write_zeroes_sectors = bdev_write_zeroes_sectors(bdev); | |
147 | ||
148 | if (max_write_zeroes_sectors == 0) | |
149 | return -EOPNOTSUPP; | |
150 | ||
151 | while (nr_sects) { | |
0a3140ea | 152 | bio = blk_next_bio(bio, bdev, 0, REQ_OP_WRITE_ZEROES, gfp_mask); |
a6f0788e | 153 | bio->bi_iter.bi_sector = sector; |
d928be9f CH |
154 | if (flags & BLKDEV_ZERO_NOUNMAP) |
155 | bio->bi_opf |= REQ_NOUNMAP; | |
a6f0788e CK |
156 | |
157 | if (nr_sects > max_write_zeroes_sectors) { | |
158 | bio->bi_iter.bi_size = max_write_zeroes_sectors << 9; | |
159 | nr_sects -= max_write_zeroes_sectors; | |
160 | sector += max_write_zeroes_sectors; | |
161 | } else { | |
162 | bio->bi_iter.bi_size = nr_sects << 9; | |
163 | nr_sects = 0; | |
164 | } | |
165 | cond_resched(); | |
166 | } | |
167 | ||
168 | *biop = bio; | |
169 | return 0; | |
170 | } | |
171 | ||
615d22a5 DLM |
172 | /* |
173 | * Convert a number of 512B sectors to a number of pages. | |
174 | * The result is limited to a number of pages that can fit into a BIO. | |
175 | * Also make sure that the result is always at least 1 (page) for the cases | |
176 | * where nr_sects is lower than the number of sectors in a page. | |
177 | */ | |
178 | static unsigned int __blkdev_sectors_to_bio_pages(sector_t nr_sects) | |
179 | { | |
09c2c359 | 180 | sector_t pages = DIV_ROUND_UP_SECTOR_T(nr_sects, PAGE_SIZE / 512); |
615d22a5 | 181 | |
a8affc03 | 182 | return min(pages, (sector_t)BIO_MAX_VECS); |
615d22a5 DLM |
183 | } |
184 | ||
425a4dba ID |
185 | static int __blkdev_issue_zero_pages(struct block_device *bdev, |
186 | sector_t sector, sector_t nr_sects, gfp_t gfp_mask, | |
187 | struct bio **biop) | |
188 | { | |
425a4dba ID |
189 | struct bio *bio = *biop; |
190 | int bi_size = 0; | |
191 | unsigned int sz; | |
192 | ||
a13553c7 ID |
193 | if (bdev_read_only(bdev)) |
194 | return -EPERM; | |
195 | ||
425a4dba | 196 | while (nr_sects != 0) { |
0a3140ea CK |
197 | bio = blk_next_bio(bio, bdev, __blkdev_sectors_to_bio_pages(nr_sects), |
198 | REQ_OP_WRITE, gfp_mask); | |
425a4dba | 199 | bio->bi_iter.bi_sector = sector; |
425a4dba ID |
200 | |
201 | while (nr_sects != 0) { | |
202 | sz = min((sector_t) PAGE_SIZE, nr_sects << 9); | |
203 | bi_size = bio_add_page(bio, ZERO_PAGE(0), sz, 0); | |
204 | nr_sects -= bi_size >> 9; | |
205 | sector += bi_size >> 9; | |
206 | if (bi_size < sz) | |
207 | break; | |
208 | } | |
209 | cond_resched(); | |
210 | } | |
211 | ||
212 | *biop = bio; | |
213 | return 0; | |
214 | } | |
215 | ||
3f14d792 | 216 | /** |
e73c23ff | 217 | * __blkdev_issue_zeroout - generate number of zero filed write bios |
3f14d792 DM |
218 | * @bdev: blockdev to issue |
219 | * @sector: start sector | |
220 | * @nr_sects: number of sectors to write | |
221 | * @gfp_mask: memory allocation flags (for bio_alloc) | |
e73c23ff | 222 | * @biop: pointer to anchor bio |
ee472d83 | 223 | * @flags: controls detailed behavior |
3f14d792 DM |
224 | * |
225 | * Description: | |
ee472d83 CH |
226 | * Zero-fill a block range, either using hardware offload or by explicitly |
227 | * writing zeroes to the device. | |
228 | * | |
229 | * If a device is using logical block provisioning, the underlying space will | |
230 | * not be released if %flags contains BLKDEV_ZERO_NOUNMAP. | |
cb365b96 CH |
231 | * |
232 | * If %flags contains BLKDEV_ZERO_NOFALLBACK, the function will return | |
233 | * -EOPNOTSUPP if no explicit hardware offload for zeroing is provided. | |
3f14d792 | 234 | */ |
e73c23ff CK |
235 | int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, |
236 | sector_t nr_sects, gfp_t gfp_mask, struct bio **biop, | |
ee472d83 | 237 | unsigned flags) |
3f14d792 | 238 | { |
18edc8ea | 239 | int ret; |
28b2be20 DW |
240 | sector_t bs_mask; |
241 | ||
242 | bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1; | |
243 | if ((sector | nr_sects) & bs_mask) | |
244 | return -EINVAL; | |
3f14d792 | 245 | |
a6f0788e | 246 | ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects, gfp_mask, |
d928be9f | 247 | biop, flags); |
cb365b96 | 248 | if (ret != -EOPNOTSUPP || (flags & BLKDEV_ZERO_NOFALLBACK)) |
425a4dba | 249 | return ret; |
3f14d792 | 250 | |
425a4dba ID |
251 | return __blkdev_issue_zero_pages(bdev, sector, nr_sects, gfp_mask, |
252 | biop); | |
3f14d792 | 253 | } |
e73c23ff | 254 | EXPORT_SYMBOL(__blkdev_issue_zeroout); |
579e8f3c MP |
255 | |
256 | /** | |
257 | * blkdev_issue_zeroout - zero-fill a block range | |
258 | * @bdev: blockdev to write | |
259 | * @sector: start sector | |
260 | * @nr_sects: number of sectors to write | |
261 | * @gfp_mask: memory allocation flags (for bio_alloc) | |
ee472d83 | 262 | * @flags: controls detailed behavior |
579e8f3c MP |
263 | * |
264 | * Description: | |
ee472d83 CH |
265 | * Zero-fill a block range, either using hardware offload or by explicitly |
266 | * writing zeroes to the device. See __blkdev_issue_zeroout() for the | |
267 | * valid values for %flags. | |
579e8f3c | 268 | */ |
579e8f3c | 269 | int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, |
ee472d83 | 270 | sector_t nr_sects, gfp_t gfp_mask, unsigned flags) |
579e8f3c | 271 | { |
d5ce4c31 ID |
272 | int ret = 0; |
273 | sector_t bs_mask; | |
274 | struct bio *bio; | |
e73c23ff | 275 | struct blk_plug plug; |
d5ce4c31 | 276 | bool try_write_zeroes = !!bdev_write_zeroes_sectors(bdev); |
d93ba7a5 | 277 | |
d5ce4c31 ID |
278 | bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1; |
279 | if ((sector | nr_sects) & bs_mask) | |
280 | return -EINVAL; | |
281 | ||
282 | retry: | |
283 | bio = NULL; | |
e73c23ff | 284 | blk_start_plug(&plug); |
d5ce4c31 ID |
285 | if (try_write_zeroes) { |
286 | ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects, | |
287 | gfp_mask, &bio, flags); | |
288 | } else if (!(flags & BLKDEV_ZERO_NOFALLBACK)) { | |
289 | ret = __blkdev_issue_zero_pages(bdev, sector, nr_sects, | |
290 | gfp_mask, &bio); | |
291 | } else { | |
292 | /* No zeroing offload support */ | |
293 | ret = -EOPNOTSUPP; | |
294 | } | |
e73c23ff CK |
295 | if (ret == 0 && bio) { |
296 | ret = submit_bio_wait(bio); | |
297 | bio_put(bio); | |
298 | } | |
299 | blk_finish_plug(&plug); | |
d5ce4c31 ID |
300 | if (ret && try_write_zeroes) { |
301 | if (!(flags & BLKDEV_ZERO_NOFALLBACK)) { | |
302 | try_write_zeroes = false; | |
303 | goto retry; | |
304 | } | |
305 | if (!bdev_write_zeroes_sectors(bdev)) { | |
306 | /* | |
307 | * Zeroing offload support was indicated, but the | |
308 | * device reported ILLEGAL REQUEST (for some devices | |
309 | * there is no non-destructive way to verify whether | |
310 | * WRITE ZEROES is actually supported). | |
311 | */ | |
312 | ret = -EOPNOTSUPP; | |
313 | } | |
314 | } | |
579e8f3c | 315 | |
e73c23ff | 316 | return ret; |
579e8f3c | 317 | } |
3f14d792 | 318 | EXPORT_SYMBOL(blkdev_issue_zeroout); |