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 static struct bio *next_bio(struct bio *bio, unsigned int nr_pages,
>> 14 gfp_t gfp)
14 { 15 {
15 unsigned int discard_granularity = bde !! 16 struct bio *new = bio_alloc(gfp, nr_pages);
16 sector_t granularity_aligned_sector; <<
17 17
18 if (bdev_is_partition(bdev)) !! 18 if (bio) {
19 sector += bdev->bd_start_sect; !! 19 bio_chain(bio, new);
20 !! 20 submit_bio(bio);
21 granularity_aligned_sector = !! 21 }
22 round_up(sector, discard_granu <<
23 22
24 /* !! 23 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 } 24 }
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;
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 bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
>> 52 if ((sector | nr_sects) & bs_mask)
>> 53 return -EINVAL;
>> 54
>> 55 if (!nr_sects)
>> 56 return -EINVAL;
67 57
68 while ((bio = blk_alloc_discard_bio(bd !! 58 while (nr_sects) {
69 gfp_mask))) !! 59 sector_t req_sects = min_t(sector_t, nr_sects,
70 *biop = bio_chain_and_submit(* !! 60 bio_allowed_max_sectors(q));
>> 61
>> 62 WARN_ON_ONCE((req_sects << 9) > UINT_MAX);
>> 63
>> 64 bio = next_bio(bio, 0, gfp_mask);
>> 65 bio->bi_iter.bi_sector = sector;
>> 66 bio_set_dev(bio, bdev);
>> 67 bio_set_op_attrs(bio, op, 0);
>> 68
>> 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;
71 return 0; 83 return 0;
72 } 84 }
73 EXPORT_SYMBOL(__blkdev_issue_discard); 85 EXPORT_SYMBOL(__blkdev_issue_discard);
74 86
75 /** 87 /**
76 * blkdev_issue_discard - queue a discard 88 * blkdev_issue_discard - queue a discard
77 * @bdev: blockdev to issue discard for 89 * @bdev: blockdev to issue discard for
78 * @sector: start sector 90 * @sector: start sector
79 * @nr_sects: number of sectors to discard 91 * @nr_sects: number of sectors to discard
80 * @gfp_mask: memory allocation flags (for b 92 * @gfp_mask: memory allocation flags (for bio_alloc)
>> 93 * @flags: BLKDEV_DISCARD_* flags to control behaviour
81 * 94 *
82 * Description: 95 * Description:
83 * Issue a discard request for the sectors 96 * Issue a discard request for the sectors in question.
84 */ 97 */
85 int blkdev_issue_discard(struct block_device * 98 int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
86 sector_t nr_sects, gfp_t gfp_m !! 99 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags)
87 { 100 {
88 struct bio *bio = NULL; 101 struct bio *bio = NULL;
89 struct blk_plug plug; 102 struct blk_plug plug;
90 int ret; 103 int ret;
91 104
92 blk_start_plug(&plug); 105 blk_start_plug(&plug);
93 ret = __blkdev_issue_discard(bdev, sec !! 106 ret = __blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask, flags,
>> 107 &bio);
94 if (!ret && bio) { 108 if (!ret && bio) {
95 ret = submit_bio_wait(bio); 109 ret = submit_bio_wait(bio);
96 if (ret == -EOPNOTSUPP) 110 if (ret == -EOPNOTSUPP)
97 ret = 0; 111 ret = 0;
98 bio_put(bio); 112 bio_put(bio);
99 } 113 }
100 blk_finish_plug(&plug); 114 blk_finish_plug(&plug);
101 115
102 return ret; 116 return ret;
103 } 117 }
104 EXPORT_SYMBOL(blkdev_issue_discard); 118 EXPORT_SYMBOL(blkdev_issue_discard);
105 119
106 static sector_t bio_write_zeroes_limit(struct !! 120 /**
107 { !! 121 * __blkdev_issue_write_same - generate number of bios with same page
108 sector_t bs_mask = (bdev_logical_block !! 122 * @bdev: target blockdev
109 !! 123 * @sector: start sector
110 return min(bdev_write_zeroes_sectors(b !! 124 * @nr_sects: number of sectors to write
111 (UINT_MAX >> SECTOR_SHIFT) & ~ !! 125 * @gfp_mask: memory allocation flags (for bio_alloc)
112 } !! 126 * @page: page containing data to write
113 !! 127 * @biop: pointer to anchor bio
114 /* !! 128 *
115 * There is no reliable way for the SCSI subsy !! 129 * Description:
116 * device supports a WRITE SAME operation with !! 130 * 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 */ 131 */
121 static void __blkdev_issue_write_zeroes(struct !! 132 static int __blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
122 sector_t sector, sector_t nr_s !! 133 sector_t nr_sects, gfp_t gfp_mask, struct page *page,
123 struct bio **biop, unsigned fl !! 134 struct bio **biop)
124 { !! 135 {
>> 136 struct request_queue *q = bdev_get_queue(bdev);
>> 137 unsigned int max_write_same_sectors;
>> 138 struct bio *bio = *biop;
>> 139 sector_t bs_mask;
125 140
126 while (nr_sects) { !! 141 if (!q)
127 unsigned int len = min(nr_sect !! 142 return -ENXIO;
128 struct bio *bio; <<
129 143
130 if ((flags & BLKDEV_ZERO_KILLA !! 144 if (bdev_read_only(bdev))
131 fatal_signal_pending(curre !! 145 return -EPERM;
132 break; <<
133 146
134 bio = bio_alloc(bdev, 0, REQ_O !! 147 bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
135 bio->bi_iter.bi_sector = secto !! 148 if ((sector | nr_sects) & bs_mask)
136 if (flags & BLKDEV_ZERO_NOUNMA !! 149 return -EINVAL;
137 bio->bi_opf |= REQ_NOU !! 150
>> 151 if (!bdev_write_same(bdev))
>> 152 return -EOPNOTSUPP;
138 153
139 bio->bi_iter.bi_size = len << !! 154 /* Ensure that max_write_same_sectors doesn't overflow bi_size */
140 *biop = bio_chain_and_submit(* !! 155 max_write_same_sectors = bio_allowed_max_sectors(q);
141 156
142 nr_sects -= len; !! 157 while (nr_sects) {
143 sector += len; !! 158 bio = next_bio(bio, 1, gfp_mask);
>> 159 bio->bi_iter.bi_sector = sector;
>> 160 bio_set_dev(bio, bdev);
>> 161 bio->bi_vcnt = 1;
>> 162 bio->bi_io_vec->bv_page = page;
>> 163 bio->bi_io_vec->bv_offset = 0;
>> 164 bio->bi_io_vec->bv_len = bdev_logical_block_size(bdev);
>> 165 bio_set_op_attrs(bio, REQ_OP_WRITE_SAME, 0);
>> 166
>> 167 if (nr_sects > max_write_same_sectors) {
>> 168 bio->bi_iter.bi_size = max_write_same_sectors << 9;
>> 169 nr_sects -= max_write_same_sectors;
>> 170 sector += max_write_same_sectors;
>> 171 } else {
>> 172 bio->bi_iter.bi_size = nr_sects << 9;
>> 173 nr_sects = 0;
>> 174 }
144 cond_resched(); 175 cond_resched();
145 } 176 }
>> 177
>> 178 *biop = bio;
>> 179 return 0;
146 } 180 }
147 181
148 static int blkdev_issue_write_zeroes(struct bl !! 182 /**
149 sector_t nr_sects, gfp_t gfp, !! 183 * blkdev_issue_write_same - queue a write same operation
>> 184 * @bdev: target blockdev
>> 185 * @sector: start sector
>> 186 * @nr_sects: number of sectors to write
>> 187 * @gfp_mask: memory allocation flags (for bio_alloc)
>> 188 * @page: page containing data
>> 189 *
>> 190 * Description:
>> 191 * Issue a write same request for the sectors in question.
>> 192 */
>> 193 int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
>> 194 sector_t nr_sects, gfp_t gfp_mask,
>> 195 struct page *page)
150 { 196 {
151 sector_t limit = bio_write_zeroes_limi <<
152 struct bio *bio = NULL; 197 struct bio *bio = NULL;
153 struct blk_plug plug; 198 struct blk_plug plug;
154 int ret = 0; !! 199 int ret;
155 200
156 blk_start_plug(&plug); 201 blk_start_plug(&plug);
157 __blkdev_issue_write_zeroes(bdev, sect !! 202 ret = __blkdev_issue_write_same(bdev, sector, nr_sects, gfp_mask, page,
158 flags, limit); !! 203 &bio);
159 if (bio) { !! 204 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); 205 ret = submit_bio_wait(bio);
167 bio_put(bio); 206 bio_put(bio);
168 } 207 }
169 blk_finish_plug(&plug); 208 blk_finish_plug(&plug);
>> 209 return ret;
>> 210 }
>> 211 EXPORT_SYMBOL(blkdev_issue_write_same);
>> 212
>> 213 static int __blkdev_issue_write_zeroes(struct block_device *bdev,
>> 214 sector_t sector, sector_t nr_sects, gfp_t gfp_mask,
>> 215 struct bio **biop, unsigned flags)
>> 216 {
>> 217 struct bio *bio = *biop;
>> 218 unsigned int max_write_zeroes_sectors;
>> 219 struct request_queue *q = bdev_get_queue(bdev);
>> 220
>> 221 if (!q)
>> 222 return -ENXIO;
>> 223
>> 224 if (bdev_read_only(bdev))
>> 225 return -EPERM;
>> 226
>> 227 /* Ensure that max_write_zeroes_sectors doesn't overflow bi_size */
>> 228 max_write_zeroes_sectors = bdev_write_zeroes_sectors(bdev);
170 229
171 /* !! 230 if (max_write_zeroes_sectors == 0)
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; 231 return -EOPNOTSUPP;
179 return ret; !! 232
>> 233 while (nr_sects) {
>> 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;
>> 240
>> 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;
>> 245 } else {
>> 246 bio->bi_iter.bi_size = nr_sects << 9;
>> 247 nr_sects = 0;
>> 248 }
>> 249 cond_resched();
>> 250 }
>> 251
>> 252 *biop = bio;
>> 253 return 0;
180 } 254 }
181 255
182 /* 256 /*
183 * Convert a number of 512B sectors to a numbe 257 * Convert a number of 512B sectors to a number of pages.
184 * The result is limited to a number of pages 258 * 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 259 * 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 260 * where nr_sects is lower than the number of sectors in a page.
187 */ 261 */
188 static unsigned int __blkdev_sectors_to_bio_pa 262 static unsigned int __blkdev_sectors_to_bio_pages(sector_t nr_sects)
189 { 263 {
190 sector_t pages = DIV_ROUND_UP_SECTOR_T 264 sector_t pages = DIV_ROUND_UP_SECTOR_T(nr_sects, PAGE_SIZE / 512);
191 265
192 return min(pages, (sector_t)BIO_MAX_VE !! 266 return min(pages, (sector_t)BIO_MAX_PAGES);
193 } 267 }
194 268
195 static void __blkdev_issue_zero_pages(struct b !! 269 static int __blkdev_issue_zero_pages(struct block_device *bdev,
196 sector_t sector, sector_t nr_s 270 sector_t sector, sector_t nr_sects, gfp_t gfp_mask,
197 struct bio **biop, unsigned in !! 271 struct bio **biop)
198 { 272 {
199 while (nr_sects) { !! 273 struct request_queue *q = bdev_get_queue(bdev);
200 unsigned int nr_vecs = __blkde !! 274 struct bio *bio = *biop;
201 struct bio *bio; !! 275 int bi_size = 0;
202 !! 276 unsigned int sz;
203 bio = bio_alloc(bdev, nr_vecs, <<
204 bio->bi_iter.bi_sector = secto <<
205 277
206 if ((flags & BLKDEV_ZERO_KILLA !! 278 if (!q)
207 fatal_signal_pending(curre !! 279 return -ENXIO;
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 } <<
226 280
227 static int blkdev_issue_zero_pages(struct bloc !! 281 if (bdev_read_only(bdev))
228 sector_t nr_sects, gfp_t gfp, !! 282 return -EPERM;
229 { <<
230 struct bio *bio = NULL; <<
231 struct blk_plug plug; <<
232 int ret = 0; <<
233 283
234 if (flags & BLKDEV_ZERO_NOFALLBACK) !! 284 while (nr_sects != 0) {
235 return -EOPNOTSUPP; !! 285 bio = next_bio(bio, __blkdev_sectors_to_bio_pages(nr_sects),
>> 286 gfp_mask);
>> 287 bio->bi_iter.bi_sector = sector;
>> 288 bio_set_dev(bio, bdev);
>> 289 bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
236 290
237 blk_start_plug(&plug); !! 291 while (nr_sects != 0) {
238 __blkdev_issue_zero_pages(bdev, sector !! 292 sz = min((sector_t) PAGE_SIZE, nr_sects << 9);
239 if (bio) { !! 293 bi_size = bio_add_page(bio, ZERO_PAGE(0), sz, 0);
240 if ((flags & BLKDEV_ZERO_KILLA !! 294 nr_sects -= bi_size >> 9;
241 fatal_signal_pending(curre !! 295 sector += bi_size >> 9;
242 bio_await_chain(bio); !! 296 if (bi_size < sz)
243 blk_finish_plug(&plug) !! 297 break;
244 return -EINTR; <<
245 } 298 }
246 ret = submit_bio_wait(bio); !! 299 cond_resched();
247 bio_put(bio); <<
248 } 300 }
249 blk_finish_plug(&plug); <<
250 301
251 return ret; !! 302 *biop = bio;
>> 303 return 0;
252 } 304 }
253 305
254 /** 306 /**
255 * __blkdev_issue_zeroout - generate number of 307 * __blkdev_issue_zeroout - generate number of zero filed write bios
256 * @bdev: blockdev to issue 308 * @bdev: blockdev to issue
257 * @sector: start sector 309 * @sector: start sector
258 * @nr_sects: number of sectors to write 310 * @nr_sects: number of sectors to write
259 * @gfp_mask: memory allocation flags (for b 311 * @gfp_mask: memory allocation flags (for bio_alloc)
260 * @biop: pointer to anchor bio 312 * @biop: pointer to anchor bio
261 * @flags: controls detailed behavior 313 * @flags: controls detailed behavior
262 * 314 *
263 * Description: 315 * Description:
264 * Zero-fill a block range, either using hard 316 * Zero-fill a block range, either using hardware offload or by explicitly
265 * writing zeroes to the device. 317 * writing zeroes to the device.
266 * 318 *
267 * If a device is using logical block provisi 319 * If a device is using logical block provisioning, the underlying space will
268 * not be released if %flags contains BLKDEV_ 320 * not be released if %flags contains BLKDEV_ZERO_NOUNMAP.
269 * 321 *
270 * If %flags contains BLKDEV_ZERO_NOFALLBACK, 322 * If %flags contains BLKDEV_ZERO_NOFALLBACK, the function will return
271 * -EOPNOTSUPP if no explicit hardware offloa 323 * -EOPNOTSUPP if no explicit hardware offload for zeroing is provided.
272 */ 324 */
273 int __blkdev_issue_zeroout(struct block_device 325 int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
274 sector_t nr_sects, gfp_t gfp_m 326 sector_t nr_sects, gfp_t gfp_mask, struct bio **biop,
275 unsigned flags) 327 unsigned flags)
276 { 328 {
277 sector_t limit = bio_write_zeroes_limi !! 329 int ret;
>> 330 sector_t bs_mask;
278 331
279 if (bdev_read_only(bdev)) !! 332 bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
280 return -EPERM; !! 333 if ((sector | nr_sects) & bs_mask)
>> 334 return -EINVAL;
281 335
282 if (limit) { !! 336 ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects, gfp_mask,
283 __blkdev_issue_write_zeroes(bd !! 337 biop, flags);
284 gfp_mask, biop !! 338 if (ret != -EOPNOTSUPP || (flags & BLKDEV_ZERO_NOFALLBACK))
285 } else { !! 339 return ret;
286 if (flags & BLKDEV_ZERO_NOFALL !! 340
287 return -EOPNOTSUPP; !! 341 return __blkdev_issue_zero_pages(bdev, sector, nr_sects, gfp_mask,
288 __blkdev_issue_zero_pages(bdev !! 342 biop);
289 biop, flags); <<
290 } <<
291 return 0; <<
292 } 343 }
293 EXPORT_SYMBOL(__blkdev_issue_zeroout); 344 EXPORT_SYMBOL(__blkdev_issue_zeroout);
294 345
295 /** 346 /**
296 * blkdev_issue_zeroout - zero-fill a block ra 347 * blkdev_issue_zeroout - zero-fill a block range
297 * @bdev: blockdev to write 348 * @bdev: blockdev to write
298 * @sector: start sector 349 * @sector: start sector
299 * @nr_sects: number of sectors to write 350 * @nr_sects: number of sectors to write
300 * @gfp_mask: memory allocation flags (for b 351 * @gfp_mask: memory allocation flags (for bio_alloc)
301 * @flags: controls detailed behavior 352 * @flags: controls detailed behavior
302 * 353 *
303 * Description: 354 * Description:
304 * Zero-fill a block range, either using hard 355 * Zero-fill a block range, either using hardware offload or by explicitly
305 * writing zeroes to the device. See __blkde 356 * writing zeroes to the device. See __blkdev_issue_zeroout() for the
306 * valid values for %flags. 357 * valid values for %flags.
307 */ 358 */
308 int blkdev_issue_zeroout(struct block_device * 359 int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
309 sector_t nr_sects, gfp_t gfp_m 360 sector_t nr_sects, gfp_t gfp_mask, unsigned flags)
310 { 361 {
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; 362 int ret = 0;
>> 363 sector_t bs_mask;
>> 364 struct bio *bio;
>> 365 struct blk_plug plug;
>> 366 bool try_write_zeroes = !!bdev_write_zeroes_sectors(bdev);
337 367
338 /* make sure that "len << SECTOR_SHIFT !! 368 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) 369 if ((sector | nr_sects) & bs_mask)
346 return -EINVAL; 370 return -EINVAL;
347 if (bdev_read_only(bdev)) <<
348 return -EPERM; <<
349 371
>> 372 retry:
>> 373 bio = NULL;
350 blk_start_plug(&plug); 374 blk_start_plug(&plug);
351 while (nr_sects) { !! 375 if (try_write_zeroes) {
352 unsigned int len = min_t(secto !! 376 ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects,
353 !! 377 gfp_mask, &bio, flags);
354 bio = blk_next_bio(bio, bdev, !! 378 } else if (!(flags & BLKDEV_ZERO_NOFALLBACK)) {
355 bio->bi_iter.bi_sector = secto !! 379 ret = __blkdev_issue_zero_pages(bdev, sector, nr_sects,
356 bio->bi_iter.bi_size = len << !! 380 gfp_mask, &bio);
357 !! 381 } else {
358 sector += len; !! 382 /* No zeroing offload support */
359 nr_sects -= len; !! 383 ret = -EOPNOTSUPP;
360 cond_resched(); <<
361 } 384 }
362 if (bio) { !! 385 if (ret == 0 && bio) {
363 ret = submit_bio_wait(bio); 386 ret = submit_bio_wait(bio);
364 bio_put(bio); 387 bio_put(bio);
365 } 388 }
366 blk_finish_plug(&plug); 389 blk_finish_plug(&plug);
>> 390 if (ret && try_write_zeroes) {
>> 391 if (!(flags & BLKDEV_ZERO_NOFALLBACK)) {
>> 392 try_write_zeroes = false;
>> 393 goto retry;
>> 394 }
>> 395 if (!bdev_write_zeroes_sectors(bdev)) {
>> 396 /*
>> 397 * Zeroing offload support was indicated, but the
>> 398 * device reported ILLEGAL REQUEST (for some devices
>> 399 * there is no non-destructive way to verify whether
>> 400 * WRITE ZEROES is actually supported).
>> 401 */
>> 402 ret = -EOPNOTSUPP;
>> 403 }
>> 404 }
367 405
368 return ret; 406 return ret;
369 } 407 }
370 EXPORT_SYMBOL(blkdev_issue_secure_erase); !! 408 EXPORT_SYMBOL(blkdev_issue_zeroout);
371 409
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.