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