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Commit | Line | Data |
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f31e7e40 DM |
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 | ||
5dba3089 LC |
12 | struct bio_batch { |
13 | atomic_t done; | |
4246a0b6 | 14 | int error; |
5dba3089 LC |
15 | struct completion *wait; |
16 | }; | |
17 | ||
4246a0b6 | 18 | static void bio_batch_end_io(struct bio *bio) |
f31e7e40 | 19 | { |
5dba3089 LC |
20 | struct bio_batch *bb = bio->bi_private; |
21 | ||
4246a0b6 CH |
22 | if (bio->bi_error && bio->bi_error != -EOPNOTSUPP) |
23 | bb->error = bio->bi_error; | |
5dba3089 LC |
24 | if (atomic_dec_and_test(&bb->done)) |
25 | complete(bb->wait); | |
f31e7e40 DM |
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 | */ | |
40 | int 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); | |
8c555367 | 45 | int type = REQ_WRITE | REQ_DISCARD; |
97597dc0 GU |
46 | unsigned int max_discard_sectors, granularity; |
47 | int alignment; | |
5dba3089 | 48 | struct bio_batch bb; |
f31e7e40 | 49 | struct bio *bio; |
f31e7e40 | 50 | int ret = 0; |
0cfbcafc | 51 | struct blk_plug plug; |
f31e7e40 DM |
52 | |
53 | if (!q) | |
54 | return -ENXIO; | |
55 | ||
56 | if (!blk_queue_discard(q)) | |
57 | return -EOPNOTSUPP; | |
58 | ||
f6ff53d3 PB |
59 | /* Zero-sector (unknown) and one-sector granularities are the same. */ |
60 | granularity = max(q->limits.discard_granularity >> 9, 1U); | |
97597dc0 | 61 | alignment = (bdev_discard_alignment(bdev) >> 9) % granularity; |
f6ff53d3 | 62 | |
10d1f9e2 JA |
63 | /* |
64 | * Ensure that max_discard_sectors is of the proper | |
c6e66634 | 65 | * granularity, so that requests stay aligned after a split. |
10d1f9e2 JA |
66 | */ |
67 | max_discard_sectors = min(q->limits.max_discard_sectors, UINT_MAX >> 9); | |
97597dc0 | 68 | max_discard_sectors -= max_discard_sectors % granularity; |
4c64500e | 69 | if (unlikely(!max_discard_sectors)) { |
0f799603 MS |
70 | /* Avoid infinite loop below. Being cautious never hurts. */ |
71 | return -EOPNOTSUPP; | |
10d1f9e2 | 72 | } |
f31e7e40 | 73 | |
dd3932ed | 74 | if (flags & BLKDEV_DISCARD_SECURE) { |
8d57a98c AH |
75 | if (!blk_queue_secdiscard(q)) |
76 | return -EOPNOTSUPP; | |
8c555367 | 77 | type |= REQ_SECURE; |
8d57a98c AH |
78 | } |
79 | ||
5dba3089 | 80 | atomic_set(&bb.done, 1); |
4246a0b6 | 81 | bb.error = 0; |
5dba3089 LC |
82 | bb.wait = &wait; |
83 | ||
0cfbcafc | 84 | blk_start_plug(&plug); |
5dba3089 | 85 | while (nr_sects) { |
c6e66634 | 86 | unsigned int req_sects; |
8dd2cb7e | 87 | sector_t end_sect, tmp; |
c6e66634 | 88 | |
f31e7e40 | 89 | bio = bio_alloc(gfp_mask, 1); |
66ac0280 CH |
90 | if (!bio) { |
91 | ret = -ENOMEM; | |
92 | break; | |
93 | } | |
94 | ||
c6e66634 PB |
95 | req_sects = min_t(sector_t, nr_sects, max_discard_sectors); |
96 | ||
97 | /* | |
98 | * If splitting a request, and the next starting sector would be | |
99 | * misaligned, stop the discard at the previous aligned sector. | |
100 | */ | |
101 | end_sect = sector + req_sects; | |
8dd2cb7e SL |
102 | tmp = end_sect; |
103 | if (req_sects < nr_sects && | |
104 | sector_div(tmp, granularity) != alignment) { | |
105 | end_sect = end_sect - alignment; | |
106 | sector_div(end_sect, granularity); | |
107 | end_sect = end_sect * granularity + alignment; | |
c6e66634 PB |
108 | req_sects = end_sect - sector; |
109 | } | |
110 | ||
4f024f37 | 111 | bio->bi_iter.bi_sector = sector; |
5dba3089 | 112 | bio->bi_end_io = bio_batch_end_io; |
f31e7e40 | 113 | bio->bi_bdev = bdev; |
5dba3089 | 114 | bio->bi_private = &bb; |
f31e7e40 | 115 | |
4f024f37 | 116 | bio->bi_iter.bi_size = req_sects << 9; |
c6e66634 PB |
117 | nr_sects -= req_sects; |
118 | sector = end_sect; | |
f31e7e40 | 119 | |
5dba3089 | 120 | atomic_inc(&bb.done); |
f31e7e40 | 121 | submit_bio(type, bio); |
c8123f8c JA |
122 | |
123 | /* | |
124 | * We can loop for a long time in here, if someone does | |
125 | * full device discards (like mkfs). Be nice and allow | |
126 | * us to schedule out to avoid softlocking if preempt | |
127 | * is disabled. | |
128 | */ | |
129 | cond_resched(); | |
5dba3089 | 130 | } |
0cfbcafc | 131 | blk_finish_plug(&plug); |
f31e7e40 | 132 | |
5dba3089 LC |
133 | /* Wait for bios in-flight */ |
134 | if (!atomic_dec_and_test(&bb.done)) | |
5577022f | 135 | wait_for_completion_io(&wait); |
f31e7e40 | 136 | |
4246a0b6 CH |
137 | if (bb.error) |
138 | return bb.error; | |
f31e7e40 | 139 | return ret; |
f31e7e40 DM |
140 | } |
141 | EXPORT_SYMBOL(blkdev_issue_discard); | |
3f14d792 | 142 | |
4363ac7c MP |
143 | /** |
144 | * blkdev_issue_write_same - queue a write same operation | |
145 | * @bdev: target blockdev | |
146 | * @sector: start sector | |
147 | * @nr_sects: number of sectors to write | |
148 | * @gfp_mask: memory allocation flags (for bio_alloc) | |
149 | * @page: page containing data to write | |
150 | * | |
151 | * Description: | |
152 | * Issue a write same request for the sectors in question. | |
153 | */ | |
154 | int blkdev_issue_write_same(struct block_device *bdev, sector_t sector, | |
155 | sector_t nr_sects, gfp_t gfp_mask, | |
156 | struct page *page) | |
157 | { | |
158 | DECLARE_COMPLETION_ONSTACK(wait); | |
159 | struct request_queue *q = bdev_get_queue(bdev); | |
160 | unsigned int max_write_same_sectors; | |
161 | struct bio_batch bb; | |
162 | struct bio *bio; | |
163 | int ret = 0; | |
164 | ||
165 | if (!q) | |
166 | return -ENXIO; | |
167 | ||
168 | max_write_same_sectors = q->limits.max_write_same_sectors; | |
169 | ||
170 | if (max_write_same_sectors == 0) | |
171 | return -EOPNOTSUPP; | |
172 | ||
173 | atomic_set(&bb.done, 1); | |
4246a0b6 | 174 | bb.error = 0; |
4363ac7c MP |
175 | bb.wait = &wait; |
176 | ||
177 | while (nr_sects) { | |
178 | bio = bio_alloc(gfp_mask, 1); | |
179 | if (!bio) { | |
180 | ret = -ENOMEM; | |
181 | break; | |
182 | } | |
183 | ||
4f024f37 | 184 | bio->bi_iter.bi_sector = sector; |
4363ac7c MP |
185 | bio->bi_end_io = bio_batch_end_io; |
186 | bio->bi_bdev = bdev; | |
187 | bio->bi_private = &bb; | |
188 | bio->bi_vcnt = 1; | |
189 | bio->bi_io_vec->bv_page = page; | |
190 | bio->bi_io_vec->bv_offset = 0; | |
191 | bio->bi_io_vec->bv_len = bdev_logical_block_size(bdev); | |
192 | ||
193 | if (nr_sects > max_write_same_sectors) { | |
4f024f37 | 194 | bio->bi_iter.bi_size = max_write_same_sectors << 9; |
4363ac7c MP |
195 | nr_sects -= max_write_same_sectors; |
196 | sector += max_write_same_sectors; | |
197 | } else { | |
4f024f37 | 198 | bio->bi_iter.bi_size = nr_sects << 9; |
4363ac7c MP |
199 | nr_sects = 0; |
200 | } | |
201 | ||
202 | atomic_inc(&bb.done); | |
203 | submit_bio(REQ_WRITE | REQ_WRITE_SAME, bio); | |
204 | } | |
205 | ||
206 | /* Wait for bios in-flight */ | |
207 | if (!atomic_dec_and_test(&bb.done)) | |
5577022f | 208 | wait_for_completion_io(&wait); |
4363ac7c | 209 | |
4246a0b6 CH |
210 | if (bb.error) |
211 | return bb.error; | |
4363ac7c MP |
212 | return ret; |
213 | } | |
214 | EXPORT_SYMBOL(blkdev_issue_write_same); | |
215 | ||
3f14d792 | 216 | /** |
291d24f6 | 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) | |
3f14d792 DM |
222 | * |
223 | * Description: | |
224 | * Generate and issue number of bios with zerofiled pages. | |
3f14d792 DM |
225 | */ |
226 | ||
35086784 FF |
227 | static int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, |
228 | sector_t nr_sects, gfp_t gfp_mask) | |
3f14d792 | 229 | { |
18edc8ea | 230 | int ret; |
3f14d792 DM |
231 | struct bio *bio; |
232 | struct bio_batch bb; | |
0aeea189 | 233 | unsigned int sz; |
3f14d792 DM |
234 | DECLARE_COMPLETION_ONSTACK(wait); |
235 | ||
0aeea189 | 236 | atomic_set(&bb.done, 1); |
4246a0b6 | 237 | bb.error = 0; |
3f14d792 | 238 | bb.wait = &wait; |
3f14d792 | 239 | |
18edc8ea | 240 | ret = 0; |
3f14d792 DM |
241 | while (nr_sects != 0) { |
242 | bio = bio_alloc(gfp_mask, | |
243 | min(nr_sects, (sector_t)BIO_MAX_PAGES)); | |
18edc8ea DM |
244 | if (!bio) { |
245 | ret = -ENOMEM; | |
3f14d792 | 246 | break; |
18edc8ea | 247 | } |
3f14d792 | 248 | |
4f024f37 | 249 | bio->bi_iter.bi_sector = sector; |
3f14d792 DM |
250 | bio->bi_bdev = bdev; |
251 | bio->bi_end_io = bio_batch_end_io; | |
dd3932ed | 252 | bio->bi_private = &bb; |
3f14d792 | 253 | |
0341aafb JA |
254 | while (nr_sects != 0) { |
255 | sz = min((sector_t) PAGE_SIZE >> 9 , nr_sects); | |
3f14d792 DM |
256 | ret = bio_add_page(bio, ZERO_PAGE(0), sz << 9, 0); |
257 | nr_sects -= ret >> 9; | |
258 | sector += ret >> 9; | |
259 | if (ret < (sz << 9)) | |
260 | break; | |
261 | } | |
18edc8ea | 262 | ret = 0; |
0aeea189 | 263 | atomic_inc(&bb.done); |
3f14d792 DM |
264 | submit_bio(WRITE, bio); |
265 | } | |
3f14d792 | 266 | |
dd3932ed | 267 | /* Wait for bios in-flight */ |
0aeea189 | 268 | if (!atomic_dec_and_test(&bb.done)) |
5577022f | 269 | wait_for_completion_io(&wait); |
3f14d792 | 270 | |
4246a0b6 CH |
271 | if (bb.error) |
272 | return bb.error; | |
3f14d792 DM |
273 | return ret; |
274 | } | |
579e8f3c MP |
275 | |
276 | /** | |
277 | * blkdev_issue_zeroout - zero-fill a block range | |
278 | * @bdev: blockdev to write | |
279 | * @sector: start sector | |
280 | * @nr_sects: number of sectors to write | |
281 | * @gfp_mask: memory allocation flags (for bio_alloc) | |
d93ba7a5 | 282 | * @discard: whether to discard the block range |
579e8f3c MP |
283 | * |
284 | * Description: | |
d93ba7a5 MP |
285 | * Zero-fill a block range. If the discard flag is set and the block |
286 | * device guarantees that subsequent READ operations to the block range | |
287 | * in question will return zeroes, the blocks will be discarded. Should | |
288 | * the discard request fail, if the discard flag is not set, or if | |
289 | * discard_zeroes_data is not supported, this function will resort to | |
290 | * zeroing the blocks manually, thus provisioning (allocating, | |
291 | * anchoring) them. If the block device supports the WRITE SAME command | |
292 | * blkdev_issue_zeroout() will use it to optimize the process of | |
293 | * clearing the block range. Otherwise the zeroing will be performed | |
294 | * using regular WRITE calls. | |
579e8f3c MP |
295 | */ |
296 | ||
297 | int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, | |
d93ba7a5 | 298 | sector_t nr_sects, gfp_t gfp_mask, bool discard) |
579e8f3c | 299 | { |
d93ba7a5 | 300 | struct request_queue *q = bdev_get_queue(bdev); |
d93ba7a5 | 301 | |
9f9ee1f2 MP |
302 | if (discard && blk_queue_discard(q) && q->limits.discard_zeroes_data && |
303 | blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask, 0) == 0) | |
304 | return 0; | |
d93ba7a5 | 305 | |
9f9ee1f2 MP |
306 | if (bdev_write_same(bdev) && |
307 | blkdev_issue_write_same(bdev, sector, nr_sects, gfp_mask, | |
308 | ZERO_PAGE(0)) == 0) | |
309 | return 0; | |
579e8f3c MP |
310 | |
311 | return __blkdev_issue_zeroout(bdev, sector, nr_sects, gfp_mask); | |
312 | } | |
3f14d792 | 313 | EXPORT_SYMBOL(blkdev_issue_zeroout); |