1 // SPDX-License-Identifier: GPL-2.0 1 // SPDX-License-Identifier: GPL-2.0
2 /* 2 /*
3 * Functions related to generic helpers functi 3 * Functions related to generic helpers functions
4 */ 4 */
5 #include <linux/kernel.h> 5 #include <linux/kernel.h>
6 #include <linux/module.h> 6 #include <linux/module.h>
7 #include <linux/bio.h> 7 #include <linux/bio.h>
8 #include <linux/blkdev.h> 8 #include <linux/blkdev.h>
9 #include <linux/scatterlist.h> 9 #include <linux/scatterlist.h>
10 10
11 #include "blk.h" 11 #include "blk.h"
12 12
13 static sector_t bio_discard_limit(struct block !! 13 struct bio *blk_next_bio(struct bio *bio, unsigned int nr_pages, gfp_t gfp)
14 { 14 {
15 unsigned int discard_granularity = bde !! 15 struct bio *new = bio_alloc(gfp, nr_pages);
16 sector_t granularity_aligned_sector; <<
17 16
18 if (bdev_is_partition(bdev)) !! 17 if (bio) {
19 sector += bdev->bd_start_sect; !! 18 bio_chain(bio, new);
20 !! 19 submit_bio(bio);
21 granularity_aligned_sector = !! 20 }
22 round_up(sector, discard_granu <<
23 21
24 /* !! 22 return new;
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 } 23 }
>> 24 EXPORT_SYMBOL_GPL(blk_next_bio);
37 25
38 struct bio *blk_alloc_discard_bio(struct block !! 26 int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
39 sector_t *sector, sector_t *nr !! 27 sector_t nr_sects, gfp_t gfp_mask, int flags,
>> 28 struct bio **biop)
40 { 29 {
41 sector_t bio_sects = min(*nr_sects, bi !! 30 struct request_queue *q = bdev_get_queue(bdev);
42 struct bio *bio; !! 31 struct bio *bio = *biop;
>> 32 unsigned int op;
>> 33 sector_t bs_mask, part_offset = 0;
43 34
44 if (!bio_sects) !! 35 if (!q)
45 return NULL; !! 36 return -ENXIO;
46 37
47 bio = bio_alloc(bdev, 0, REQ_OP_DISCAR !! 38 if (bdev_read_only(bdev))
48 if (!bio) !! 39 return -EPERM;
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 40
63 int __blkdev_issue_discard(struct block_device !! 41 if (flags & BLKDEV_DISCARD_SECURE) {
64 sector_t nr_sects, gfp_t gfp_m !! 42 if (!blk_queue_secure_erase(q))
65 { !! 43 return -EOPNOTSUPP;
66 struct bio *bio; !! 44 op = REQ_OP_SECURE_ERASE;
>> 45 } else {
>> 46 if (!blk_queue_discard(q))
>> 47 return -EOPNOTSUPP;
>> 48 op = REQ_OP_DISCARD;
>> 49 }
>> 50
>> 51 /* In case the discard granularity isn't set by buggy device driver */
>> 52 if (WARN_ON_ONCE(!q->limits.discard_granularity)) {
>> 53 char dev_name[BDEVNAME_SIZE];
>> 54
>> 55 bdevname(bdev, dev_name);
>> 56 pr_err_ratelimited("%s: Error: discard_granularity is 0.\n", dev_name);
>> 57 return -EOPNOTSUPP;
>> 58 }
>> 59
>> 60 bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
>> 61 if ((sector | nr_sects) & bs_mask)
>> 62 return -EINVAL;
>> 63
>> 64 if (!nr_sects)
>> 65 return -EINVAL;
>> 66
>> 67 /* In case the discard request is in a partition */
>> 68 if (bdev_is_partition(bdev))
>> 69 part_offset = bdev->bd_start_sect;
>> 70
>> 71 while (nr_sects) {
>> 72 sector_t granularity_aligned_lba, req_sects;
>> 73 sector_t sector_mapped = sector + part_offset;
>> 74
>> 75 granularity_aligned_lba = round_up(sector_mapped,
>> 76 q->limits.discard_granularity >> SECTOR_SHIFT);
>> 77
>> 78 /*
>> 79 * Check whether the discard bio starts at a discard_granularity
>> 80 * aligned LBA,
>> 81 * - If no: set (granularity_aligned_lba - sector_mapped) to
>> 82 * bi_size of the first split bio, then the second bio will
>> 83 * start at a discard_granularity aligned LBA on the device.
>> 84 * - If yes: use bio_aligned_discard_max_sectors() as the max
>> 85 * possible bi_size of the first split bio. Then when this bio
>> 86 * is split in device drive, the split ones are very probably
>> 87 * to be aligned to discard_granularity of the device's queue.
>> 88 */
>> 89 if (granularity_aligned_lba == sector_mapped)
>> 90 req_sects = min_t(sector_t, nr_sects,
>> 91 bio_aligned_discard_max_sectors(q));
>> 92 else
>> 93 req_sects = min_t(sector_t, nr_sects,
>> 94 granularity_aligned_lba - sector_mapped);
>> 95
>> 96 WARN_ON_ONCE((req_sects << 9) > UINT_MAX);
67 97
68 while ((bio = blk_alloc_discard_bio(bd !! 98 bio = blk_next_bio(bio, 0, gfp_mask);
69 gfp_mask))) !! 99 bio->bi_iter.bi_sector = sector;
70 *biop = bio_chain_and_submit(* !! 100 bio_set_dev(bio, bdev);
>> 101 bio_set_op_attrs(bio, op, 0);
>> 102
>> 103 bio->bi_iter.bi_size = req_sects << 9;
>> 104 sector += req_sects;
>> 105 nr_sects -= req_sects;
>> 106
>> 107 /*
>> 108 * We can loop for a long time in here, if someone does
>> 109 * full device discards (like mkfs). Be nice and allow
>> 110 * us to schedule out to avoid softlocking if preempt
>> 111 * is disabled.
>> 112 */
>> 113 cond_resched();
>> 114 }
>> 115
>> 116 *biop = bio;
71 return 0; 117 return 0;
72 } 118 }
73 EXPORT_SYMBOL(__blkdev_issue_discard); 119 EXPORT_SYMBOL(__blkdev_issue_discard);
74 120
75 /** 121 /**
76 * blkdev_issue_discard - queue a discard 122 * blkdev_issue_discard - queue a discard
77 * @bdev: blockdev to issue discard for 123 * @bdev: blockdev to issue discard for
78 * @sector: start sector 124 * @sector: start sector
79 * @nr_sects: number of sectors to discard 125 * @nr_sects: number of sectors to discard
80 * @gfp_mask: memory allocation flags (for b 126 * @gfp_mask: memory allocation flags (for bio_alloc)
>> 127 * @flags: BLKDEV_DISCARD_* flags to control behaviour
81 * 128 *
82 * Description: 129 * Description:
83 * Issue a discard request for the sectors 130 * Issue a discard request for the sectors in question.
84 */ 131 */
85 int blkdev_issue_discard(struct block_device * 132 int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
86 sector_t nr_sects, gfp_t gfp_m !! 133 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags)
87 { 134 {
88 struct bio *bio = NULL; 135 struct bio *bio = NULL;
89 struct blk_plug plug; 136 struct blk_plug plug;
90 int ret; 137 int ret;
91 138
92 blk_start_plug(&plug); 139 blk_start_plug(&plug);
93 ret = __blkdev_issue_discard(bdev, sec !! 140 ret = __blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask, flags,
>> 141 &bio);
94 if (!ret && bio) { 142 if (!ret && bio) {
95 ret = submit_bio_wait(bio); 143 ret = submit_bio_wait(bio);
96 if (ret == -EOPNOTSUPP) 144 if (ret == -EOPNOTSUPP)
97 ret = 0; 145 ret = 0;
98 bio_put(bio); 146 bio_put(bio);
99 } 147 }
100 blk_finish_plug(&plug); 148 blk_finish_plug(&plug);
101 149
102 return ret; 150 return ret;
103 } 151 }
104 EXPORT_SYMBOL(blkdev_issue_discard); 152 EXPORT_SYMBOL(blkdev_issue_discard);
105 153
106 static sector_t bio_write_zeroes_limit(struct !! 154 /**
107 { !! 155 * __blkdev_issue_write_same - generate number of bios with same page
108 sector_t bs_mask = (bdev_logical_block !! 156 * @bdev: target blockdev
109 !! 157 * @sector: start sector
110 return min(bdev_write_zeroes_sectors(b !! 158 * @nr_sects: number of sectors to write
111 (UINT_MAX >> SECTOR_SHIFT) & ~ !! 159 * @gfp_mask: memory allocation flags (for bio_alloc)
112 } !! 160 * @page: page containing data to write
113 !! 161 * @biop: pointer to anchor bio
114 /* !! 162 *
115 * There is no reliable way for the SCSI subsy !! 163 * Description:
116 * device supports a WRITE SAME operation with !! 164 * Generate and issue number of bios(REQ_OP_WRITE_SAME) with same page.
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 */ 165 */
121 static void __blkdev_issue_write_zeroes(struct !! 166 static int __blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
122 sector_t sector, sector_t nr_s !! 167 sector_t nr_sects, gfp_t gfp_mask, struct page *page,
123 struct bio **biop, unsigned fl !! 168 struct bio **biop)
124 { !! 169 {
>> 170 struct request_queue *q = bdev_get_queue(bdev);
>> 171 unsigned int max_write_same_sectors;
>> 172 struct bio *bio = *biop;
>> 173 sector_t bs_mask;
125 174
126 while (nr_sects) { !! 175 if (!q)
127 unsigned int len = min(nr_sect !! 176 return -ENXIO;
128 struct bio *bio; <<
129 177
130 if ((flags & BLKDEV_ZERO_KILLA !! 178 if (bdev_read_only(bdev))
131 fatal_signal_pending(curre !! 179 return -EPERM;
132 break; <<
133 180
134 bio = bio_alloc(bdev, 0, REQ_O !! 181 bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
135 bio->bi_iter.bi_sector = secto !! 182 if ((sector | nr_sects) & bs_mask)
136 if (flags & BLKDEV_ZERO_NOUNMA !! 183 return -EINVAL;
137 bio->bi_opf |= REQ_NOU !! 184
>> 185 if (!bdev_write_same(bdev))
>> 186 return -EOPNOTSUPP;
138 187
139 bio->bi_iter.bi_size = len << !! 188 /* Ensure that max_write_same_sectors doesn't overflow bi_size */
140 *biop = bio_chain_and_submit(* !! 189 max_write_same_sectors = bio_allowed_max_sectors(q);
141 190
142 nr_sects -= len; !! 191 while (nr_sects) {
143 sector += len; !! 192 bio = blk_next_bio(bio, 1, gfp_mask);
>> 193 bio->bi_iter.bi_sector = sector;
>> 194 bio_set_dev(bio, bdev);
>> 195 bio->bi_vcnt = 1;
>> 196 bio->bi_io_vec->bv_page = page;
>> 197 bio->bi_io_vec->bv_offset = 0;
>> 198 bio->bi_io_vec->bv_len = bdev_logical_block_size(bdev);
>> 199 bio_set_op_attrs(bio, REQ_OP_WRITE_SAME, 0);
>> 200
>> 201 if (nr_sects > max_write_same_sectors) {
>> 202 bio->bi_iter.bi_size = max_write_same_sectors << 9;
>> 203 nr_sects -= max_write_same_sectors;
>> 204 sector += max_write_same_sectors;
>> 205 } else {
>> 206 bio->bi_iter.bi_size = nr_sects << 9;
>> 207 nr_sects = 0;
>> 208 }
144 cond_resched(); 209 cond_resched();
145 } 210 }
>> 211
>> 212 *biop = bio;
>> 213 return 0;
146 } 214 }
147 215
148 static int blkdev_issue_write_zeroes(struct bl !! 216 /**
149 sector_t nr_sects, gfp_t gfp, !! 217 * blkdev_issue_write_same - queue a write same operation
>> 218 * @bdev: target blockdev
>> 219 * @sector: start sector
>> 220 * @nr_sects: number of sectors to write
>> 221 * @gfp_mask: memory allocation flags (for bio_alloc)
>> 222 * @page: page containing data
>> 223 *
>> 224 * Description:
>> 225 * Issue a write same request for the sectors in question.
>> 226 */
>> 227 int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
>> 228 sector_t nr_sects, gfp_t gfp_mask,
>> 229 struct page *page)
150 { 230 {
151 sector_t limit = bio_write_zeroes_limi <<
152 struct bio *bio = NULL; 231 struct bio *bio = NULL;
153 struct blk_plug plug; 232 struct blk_plug plug;
154 int ret = 0; !! 233 int ret;
155 234
156 blk_start_plug(&plug); 235 blk_start_plug(&plug);
157 __blkdev_issue_write_zeroes(bdev, sect !! 236 ret = __blkdev_issue_write_same(bdev, sector, nr_sects, gfp_mask, page,
158 flags, limit); !! 237 &bio);
159 if (bio) { !! 238 if (ret == 0 && 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); 239 ret = submit_bio_wait(bio);
167 bio_put(bio); 240 bio_put(bio);
168 } 241 }
169 blk_finish_plug(&plug); 242 blk_finish_plug(&plug);
>> 243 return ret;
>> 244 }
>> 245 EXPORT_SYMBOL(blkdev_issue_write_same);
>> 246
>> 247 static int __blkdev_issue_write_zeroes(struct block_device *bdev,
>> 248 sector_t sector, sector_t nr_sects, gfp_t gfp_mask,
>> 249 struct bio **biop, unsigned flags)
>> 250 {
>> 251 struct bio *bio = *biop;
>> 252 unsigned int max_write_zeroes_sectors;
>> 253 struct request_queue *q = bdev_get_queue(bdev);
>> 254
>> 255 if (!q)
>> 256 return -ENXIO;
170 257
171 /* !! 258 if (bdev_read_only(bdev))
172 * For some devices there is no non-de !! 259 return -EPERM;
173 * WRITE ZEROES is actually supported. !! 260
174 * on an I/O error, in which case we'l !! 261 /* Ensure that max_write_zeroes_sectors doesn't overflow bi_size */
175 * "not supported" here. !! 262 max_write_zeroes_sectors = bdev_write_zeroes_sectors(bdev);
176 */ !! 263
177 if (ret && !bdev_write_zeroes_sectors( !! 264 if (max_write_zeroes_sectors == 0)
178 return -EOPNOTSUPP; 265 return -EOPNOTSUPP;
179 return ret; !! 266
>> 267 while (nr_sects) {
>> 268 bio = blk_next_bio(bio, 0, gfp_mask);
>> 269 bio->bi_iter.bi_sector = sector;
>> 270 bio_set_dev(bio, bdev);
>> 271 bio->bi_opf = REQ_OP_WRITE_ZEROES;
>> 272 if (flags & BLKDEV_ZERO_NOUNMAP)
>> 273 bio->bi_opf |= REQ_NOUNMAP;
>> 274
>> 275 if (nr_sects > max_write_zeroes_sectors) {
>> 276 bio->bi_iter.bi_size = max_write_zeroes_sectors << 9;
>> 277 nr_sects -= max_write_zeroes_sectors;
>> 278 sector += max_write_zeroes_sectors;
>> 279 } else {
>> 280 bio->bi_iter.bi_size = nr_sects << 9;
>> 281 nr_sects = 0;
>> 282 }
>> 283 cond_resched();
>> 284 }
>> 285
>> 286 *biop = bio;
>> 287 return 0;
180 } 288 }
181 289
182 /* 290 /*
183 * Convert a number of 512B sectors to a numbe 291 * Convert a number of 512B sectors to a number of pages.
184 * The result is limited to a number of pages 292 * The result is limited to a number of pages that can fit into a BIO.
185 * Also make sure that the result is always at 293 * Also make sure that the result is always at least 1 (page) for the cases
186 * where nr_sects is lower than the number of 294 * where nr_sects is lower than the number of sectors in a page.
187 */ 295 */
188 static unsigned int __blkdev_sectors_to_bio_pa 296 static unsigned int __blkdev_sectors_to_bio_pages(sector_t nr_sects)
189 { 297 {
190 sector_t pages = DIV_ROUND_UP_SECTOR_T 298 sector_t pages = DIV_ROUND_UP_SECTOR_T(nr_sects, PAGE_SIZE / 512);
191 299
192 return min(pages, (sector_t)BIO_MAX_VE 300 return min(pages, (sector_t)BIO_MAX_VECS);
193 } 301 }
194 302
195 static void __blkdev_issue_zero_pages(struct b !! 303 static int __blkdev_issue_zero_pages(struct block_device *bdev,
196 sector_t sector, sector_t nr_s 304 sector_t sector, sector_t nr_sects, gfp_t gfp_mask,
197 struct bio **biop, unsigned in !! 305 struct bio **biop)
198 { 306 {
199 while (nr_sects) { !! 307 struct request_queue *q = bdev_get_queue(bdev);
200 unsigned int nr_vecs = __blkde !! 308 struct bio *bio = *biop;
201 struct bio *bio; !! 309 int bi_size = 0;
>> 310 unsigned int sz;
202 311
203 bio = bio_alloc(bdev, nr_vecs, !! 312 if (!q)
204 bio->bi_iter.bi_sector = secto !! 313 return -ENXIO;
205 314
206 if ((flags & BLKDEV_ZERO_KILLA !! 315 if (bdev_read_only(bdev))
207 fatal_signal_pending(curre !! 316 return -EPERM;
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; <<
233 317
234 if (flags & BLKDEV_ZERO_NOFALLBACK) !! 318 while (nr_sects != 0) {
235 return -EOPNOTSUPP; !! 319 bio = blk_next_bio(bio, __blkdev_sectors_to_bio_pages(nr_sects),
>> 320 gfp_mask);
>> 321 bio->bi_iter.bi_sector = sector;
>> 322 bio_set_dev(bio, bdev);
>> 323 bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
236 324
237 blk_start_plug(&plug); !! 325 while (nr_sects != 0) {
238 __blkdev_issue_zero_pages(bdev, sector !! 326 sz = min((sector_t) PAGE_SIZE, nr_sects << 9);
239 if (bio) { !! 327 bi_size = bio_add_page(bio, ZERO_PAGE(0), sz, 0);
240 if ((flags & BLKDEV_ZERO_KILLA !! 328 nr_sects -= bi_size >> 9;
241 fatal_signal_pending(curre !! 329 sector += bi_size >> 9;
242 bio_await_chain(bio); !! 330 if (bi_size < sz)
243 blk_finish_plug(&plug) !! 331 break;
244 return -EINTR; <<
245 } 332 }
246 ret = submit_bio_wait(bio); !! 333 cond_resched();
247 bio_put(bio); <<
248 } 334 }
249 blk_finish_plug(&plug); <<
250 335
251 return ret; !! 336 *biop = bio;
>> 337 return 0;
252 } 338 }
253 339
254 /** 340 /**
255 * __blkdev_issue_zeroout - generate number of 341 * __blkdev_issue_zeroout - generate number of zero filed write bios
256 * @bdev: blockdev to issue 342 * @bdev: blockdev to issue
257 * @sector: start sector 343 * @sector: start sector
258 * @nr_sects: number of sectors to write 344 * @nr_sects: number of sectors to write
259 * @gfp_mask: memory allocation flags (for b 345 * @gfp_mask: memory allocation flags (for bio_alloc)
260 * @biop: pointer to anchor bio 346 * @biop: pointer to anchor bio
261 * @flags: controls detailed behavior 347 * @flags: controls detailed behavior
262 * 348 *
263 * Description: 349 * Description:
264 * Zero-fill a block range, either using hard 350 * Zero-fill a block range, either using hardware offload or by explicitly
265 * writing zeroes to the device. 351 * writing zeroes to the device.
266 * 352 *
267 * If a device is using logical block provisi 353 * If a device is using logical block provisioning, the underlying space will
268 * not be released if %flags contains BLKDEV_ 354 * not be released if %flags contains BLKDEV_ZERO_NOUNMAP.
269 * 355 *
270 * If %flags contains BLKDEV_ZERO_NOFALLBACK, 356 * If %flags contains BLKDEV_ZERO_NOFALLBACK, the function will return
271 * -EOPNOTSUPP if no explicit hardware offloa 357 * -EOPNOTSUPP if no explicit hardware offload for zeroing is provided.
272 */ 358 */
273 int __blkdev_issue_zeroout(struct block_device 359 int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
274 sector_t nr_sects, gfp_t gfp_m 360 sector_t nr_sects, gfp_t gfp_mask, struct bio **biop,
275 unsigned flags) 361 unsigned flags)
276 { 362 {
277 sector_t limit = bio_write_zeroes_limi !! 363 int ret;
>> 364 sector_t bs_mask;
278 365
279 if (bdev_read_only(bdev)) !! 366 bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
280 return -EPERM; !! 367 if ((sector | nr_sects) & bs_mask)
>> 368 return -EINVAL;
281 369
282 if (limit) { !! 370 ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects, gfp_mask,
283 __blkdev_issue_write_zeroes(bd !! 371 biop, flags);
284 gfp_mask, biop !! 372 if (ret != -EOPNOTSUPP || (flags & BLKDEV_ZERO_NOFALLBACK))
285 } else { !! 373 return ret;
286 if (flags & BLKDEV_ZERO_NOFALL !! 374
287 return -EOPNOTSUPP; !! 375 return __blkdev_issue_zero_pages(bdev, sector, nr_sects, gfp_mask,
288 __blkdev_issue_zero_pages(bdev !! 376 biop);
289 biop, flags); <<
290 } <<
291 return 0; <<
292 } 377 }
293 EXPORT_SYMBOL(__blkdev_issue_zeroout); 378 EXPORT_SYMBOL(__blkdev_issue_zeroout);
294 379
295 /** 380 /**
296 * blkdev_issue_zeroout - zero-fill a block ra 381 * blkdev_issue_zeroout - zero-fill a block range
297 * @bdev: blockdev to write 382 * @bdev: blockdev to write
298 * @sector: start sector 383 * @sector: start sector
299 * @nr_sects: number of sectors to write 384 * @nr_sects: number of sectors to write
300 * @gfp_mask: memory allocation flags (for b 385 * @gfp_mask: memory allocation flags (for bio_alloc)
301 * @flags: controls detailed behavior 386 * @flags: controls detailed behavior
302 * 387 *
303 * Description: 388 * Description:
304 * Zero-fill a block range, either using hard 389 * Zero-fill a block range, either using hardware offload or by explicitly
305 * writing zeroes to the device. See __blkde 390 * writing zeroes to the device. See __blkdev_issue_zeroout() for the
306 * valid values for %flags. 391 * valid values for %flags.
307 */ 392 */
308 int blkdev_issue_zeroout(struct block_device * 393 int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
309 sector_t nr_sects, gfp_t gfp_m 394 sector_t nr_sects, gfp_t gfp_mask, unsigned flags)
310 { 395 {
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; 396 int ret = 0;
>> 397 sector_t bs_mask;
>> 398 struct bio *bio;
>> 399 struct blk_plug plug;
>> 400 bool try_write_zeroes = !!bdev_write_zeroes_sectors(bdev);
337 401
338 /* make sure that "len << SECTOR_SHIFT !! 402 bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
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) 403 if ((sector | nr_sects) & bs_mask)
346 return -EINVAL; 404 return -EINVAL;
347 if (bdev_read_only(bdev)) <<
348 return -EPERM; <<
349 405
>> 406 retry:
>> 407 bio = NULL;
350 blk_start_plug(&plug); 408 blk_start_plug(&plug);
351 while (nr_sects) { !! 409 if (try_write_zeroes) {
352 unsigned int len = min_t(secto !! 410 ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects,
353 !! 411 gfp_mask, &bio, flags);
354 bio = blk_next_bio(bio, bdev, !! 412 } else if (!(flags & BLKDEV_ZERO_NOFALLBACK)) {
355 bio->bi_iter.bi_sector = secto !! 413 ret = __blkdev_issue_zero_pages(bdev, sector, nr_sects,
356 bio->bi_iter.bi_size = len << !! 414 gfp_mask, &bio);
357 !! 415 } else {
358 sector += len; !! 416 /* No zeroing offload support */
359 nr_sects -= len; !! 417 ret = -EOPNOTSUPP;
360 cond_resched(); <<
361 } 418 }
362 if (bio) { !! 419 if (ret == 0 && bio) {
363 ret = submit_bio_wait(bio); 420 ret = submit_bio_wait(bio);
364 bio_put(bio); 421 bio_put(bio);
365 } 422 }
366 blk_finish_plug(&plug); 423 blk_finish_plug(&plug);
>> 424 if (ret && try_write_zeroes) {
>> 425 if (!(flags & BLKDEV_ZERO_NOFALLBACK)) {
>> 426 try_write_zeroes = false;
>> 427 goto retry;
>> 428 }
>> 429 if (!bdev_write_zeroes_sectors(bdev)) {
>> 430 /*
>> 431 * Zeroing offload support was indicated, but the
>> 432 * device reported ILLEGAL REQUEST (for some devices
>> 433 * there is no non-destructive way to verify whether
>> 434 * WRITE ZEROES is actually supported).
>> 435 */
>> 436 ret = -EOPNOTSUPP;
>> 437 }
>> 438 }
367 439
368 return ret; 440 return ret;
369 } 441 }
370 EXPORT_SYMBOL(blkdev_issue_secure_erase); !! 442 EXPORT_SYMBOL(blkdev_issue_zeroout);
371 443
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