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 | ||
9082e87b CH |
12 | static struct bio *next_bio(struct bio *bio, int rw, unsigned int nr_pages, |
13 | gfp_t gfp) | |
f31e7e40 | 14 | { |
9082e87b CH |
15 | struct bio *new = bio_alloc(gfp, nr_pages); |
16 | ||
17 | if (bio) { | |
18 | bio_chain(bio, new); | |
19 | submit_bio(rw, bio); | |
20 | } | |
5dba3089 | 21 | |
9082e87b | 22 | return new; |
f31e7e40 DM |
23 | } |
24 | ||
25 | /** | |
26 | * blkdev_issue_discard - queue a discard | |
27 | * @bdev: blockdev to issue discard for | |
28 | * @sector: start sector | |
29 | * @nr_sects: number of sectors to discard | |
30 | * @gfp_mask: memory allocation flags (for bio_alloc) | |
31 | * @flags: BLKDEV_IFL_* flags to control behaviour | |
32 | * | |
33 | * Description: | |
34 | * Issue a discard request for the sectors in question. | |
35 | */ | |
36 | int blkdev_issue_discard(struct block_device *bdev, sector_t sector, | |
37 | sector_t nr_sects, gfp_t gfp_mask, unsigned long flags) | |
38 | { | |
f31e7e40 | 39 | struct request_queue *q = bdev_get_queue(bdev); |
8c555367 | 40 | int type = REQ_WRITE | REQ_DISCARD; |
a22c4d7e ML |
41 | unsigned int granularity; |
42 | int alignment; | |
9082e87b | 43 | struct bio *bio = NULL; |
f31e7e40 | 44 | int ret = 0; |
0cfbcafc | 45 | struct blk_plug plug; |
f31e7e40 DM |
46 | |
47 | if (!q) | |
48 | return -ENXIO; | |
49 | ||
50 | if (!blk_queue_discard(q)) | |
51 | return -EOPNOTSUPP; | |
52 | ||
a22c4d7e ML |
53 | /* Zero-sector (unknown) and one-sector granularities are the same. */ |
54 | granularity = max(q->limits.discard_granularity >> 9, 1U); | |
55 | alignment = (bdev_discard_alignment(bdev) >> 9) % granularity; | |
56 | ||
dd3932ed | 57 | if (flags & BLKDEV_DISCARD_SECURE) { |
8d57a98c AH |
58 | if (!blk_queue_secdiscard(q)) |
59 | return -EOPNOTSUPP; | |
8c555367 | 60 | type |= REQ_SECURE; |
8d57a98c AH |
61 | } |
62 | ||
0cfbcafc | 63 | blk_start_plug(&plug); |
5dba3089 | 64 | while (nr_sects) { |
c6e66634 | 65 | unsigned int req_sects; |
a22c4d7e | 66 | sector_t end_sect, tmp; |
c6e66634 | 67 | |
a22c4d7e ML |
68 | /* Make sure bi_size doesn't overflow */ |
69 | req_sects = min_t(sector_t, nr_sects, UINT_MAX >> 9); | |
70 | ||
9082e87b | 71 | /** |
a22c4d7e ML |
72 | * If splitting a request, and the next starting sector would be |
73 | * misaligned, stop the discard at the previous aligned sector. | |
74 | */ | |
c6e66634 | 75 | end_sect = sector + req_sects; |
a22c4d7e ML |
76 | tmp = end_sect; |
77 | if (req_sects < nr_sects && | |
78 | sector_div(tmp, granularity) != alignment) { | |
79 | end_sect = end_sect - alignment; | |
80 | sector_div(end_sect, granularity); | |
81 | end_sect = end_sect * granularity + alignment; | |
82 | req_sects = end_sect - sector; | |
83 | } | |
c6e66634 | 84 | |
9082e87b | 85 | bio = next_bio(bio, type, 1, gfp_mask); |
4f024f37 | 86 | bio->bi_iter.bi_sector = sector; |
f31e7e40 | 87 | bio->bi_bdev = bdev; |
f31e7e40 | 88 | |
4f024f37 | 89 | bio->bi_iter.bi_size = req_sects << 9; |
c6e66634 PB |
90 | nr_sects -= req_sects; |
91 | sector = end_sect; | |
f31e7e40 | 92 | |
c8123f8c JA |
93 | /* |
94 | * We can loop for a long time in here, if someone does | |
95 | * full device discards (like mkfs). Be nice and allow | |
96 | * us to schedule out to avoid softlocking if preempt | |
97 | * is disabled. | |
98 | */ | |
99 | cond_resched(); | |
5dba3089 | 100 | } |
9082e87b CH |
101 | if (bio) |
102 | ret = submit_bio_wait(type, bio); | |
0cfbcafc | 103 | blk_finish_plug(&plug); |
f31e7e40 | 104 | |
9082e87b | 105 | return ret != -EOPNOTSUPP ? ret : 0; |
f31e7e40 DM |
106 | } |
107 | EXPORT_SYMBOL(blkdev_issue_discard); | |
3f14d792 | 108 | |
4363ac7c MP |
109 | /** |
110 | * blkdev_issue_write_same - queue a write same operation | |
111 | * @bdev: target blockdev | |
112 | * @sector: start sector | |
113 | * @nr_sects: number of sectors to write | |
114 | * @gfp_mask: memory allocation flags (for bio_alloc) | |
115 | * @page: page containing data to write | |
116 | * | |
117 | * Description: | |
118 | * Issue a write same request for the sectors in question. | |
119 | */ | |
120 | int blkdev_issue_write_same(struct block_device *bdev, sector_t sector, | |
121 | sector_t nr_sects, gfp_t gfp_mask, | |
122 | struct page *page) | |
123 | { | |
4363ac7c MP |
124 | struct request_queue *q = bdev_get_queue(bdev); |
125 | unsigned int max_write_same_sectors; | |
9082e87b | 126 | struct bio *bio = NULL; |
4363ac7c MP |
127 | int ret = 0; |
128 | ||
129 | if (!q) | |
130 | return -ENXIO; | |
131 | ||
b49a0871 ML |
132 | /* Ensure that max_write_same_sectors doesn't overflow bi_size */ |
133 | max_write_same_sectors = UINT_MAX >> 9; | |
4363ac7c | 134 | |
4363ac7c | 135 | while (nr_sects) { |
9082e87b | 136 | bio = next_bio(bio, REQ_WRITE | REQ_WRITE_SAME, 1, gfp_mask); |
4f024f37 | 137 | bio->bi_iter.bi_sector = sector; |
4363ac7c | 138 | bio->bi_bdev = bdev; |
4363ac7c MP |
139 | bio->bi_vcnt = 1; |
140 | bio->bi_io_vec->bv_page = page; | |
141 | bio->bi_io_vec->bv_offset = 0; | |
142 | bio->bi_io_vec->bv_len = bdev_logical_block_size(bdev); | |
143 | ||
144 | if (nr_sects > max_write_same_sectors) { | |
4f024f37 | 145 | bio->bi_iter.bi_size = max_write_same_sectors << 9; |
4363ac7c MP |
146 | nr_sects -= max_write_same_sectors; |
147 | sector += max_write_same_sectors; | |
148 | } else { | |
4f024f37 | 149 | bio->bi_iter.bi_size = nr_sects << 9; |
4363ac7c MP |
150 | nr_sects = 0; |
151 | } | |
4363ac7c MP |
152 | } |
153 | ||
9082e87b CH |
154 | if (bio) |
155 | ret = submit_bio_wait(REQ_WRITE | REQ_WRITE_SAME, bio); | |
156 | return ret != -EOPNOTSUPP ? ret : 0; | |
4363ac7c MP |
157 | } |
158 | EXPORT_SYMBOL(blkdev_issue_write_same); | |
159 | ||
3f14d792 | 160 | /** |
291d24f6 | 161 | * blkdev_issue_zeroout - generate number of zero filed write bios |
3f14d792 DM |
162 | * @bdev: blockdev to issue |
163 | * @sector: start sector | |
164 | * @nr_sects: number of sectors to write | |
165 | * @gfp_mask: memory allocation flags (for bio_alloc) | |
3f14d792 DM |
166 | * |
167 | * Description: | |
168 | * Generate and issue number of bios with zerofiled pages. | |
3f14d792 DM |
169 | */ |
170 | ||
35086784 FF |
171 | static int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, |
172 | sector_t nr_sects, gfp_t gfp_mask) | |
3f14d792 | 173 | { |
18edc8ea | 174 | int ret; |
9082e87b | 175 | struct bio *bio = NULL; |
0aeea189 | 176 | unsigned int sz; |
3f14d792 | 177 | |
3f14d792 | 178 | while (nr_sects != 0) { |
9082e87b CH |
179 | bio = next_bio(bio, WRITE, |
180 | min(nr_sects, (sector_t)BIO_MAX_PAGES), | |
181 | gfp_mask); | |
4f024f37 | 182 | bio->bi_iter.bi_sector = sector; |
3f14d792 | 183 | bio->bi_bdev = bdev; |
3f14d792 | 184 | |
0341aafb JA |
185 | while (nr_sects != 0) { |
186 | sz = min((sector_t) PAGE_SIZE >> 9 , nr_sects); | |
3f14d792 DM |
187 | ret = bio_add_page(bio, ZERO_PAGE(0), sz << 9, 0); |
188 | nr_sects -= ret >> 9; | |
189 | sector += ret >> 9; | |
190 | if (ret < (sz << 9)) | |
191 | break; | |
192 | } | |
3f14d792 | 193 | } |
3f14d792 | 194 | |
9082e87b CH |
195 | if (bio) |
196 | return submit_bio_wait(WRITE, bio); | |
197 | return 0; | |
3f14d792 | 198 | } |
579e8f3c MP |
199 | |
200 | /** | |
201 | * blkdev_issue_zeroout - zero-fill a block range | |
202 | * @bdev: blockdev to write | |
203 | * @sector: start sector | |
204 | * @nr_sects: number of sectors to write | |
205 | * @gfp_mask: memory allocation flags (for bio_alloc) | |
d93ba7a5 | 206 | * @discard: whether to discard the block range |
579e8f3c MP |
207 | * |
208 | * Description: | |
d93ba7a5 MP |
209 | * Zero-fill a block range. If the discard flag is set and the block |
210 | * device guarantees that subsequent READ operations to the block range | |
211 | * in question will return zeroes, the blocks will be discarded. Should | |
212 | * the discard request fail, if the discard flag is not set, or if | |
213 | * discard_zeroes_data is not supported, this function will resort to | |
214 | * zeroing the blocks manually, thus provisioning (allocating, | |
215 | * anchoring) them. If the block device supports the WRITE SAME command | |
216 | * blkdev_issue_zeroout() will use it to optimize the process of | |
217 | * clearing the block range. Otherwise the zeroing will be performed | |
218 | * using regular WRITE calls. | |
579e8f3c MP |
219 | */ |
220 | ||
221 | int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, | |
d93ba7a5 | 222 | sector_t nr_sects, gfp_t gfp_mask, bool discard) |
579e8f3c | 223 | { |
d93ba7a5 | 224 | struct request_queue *q = bdev_get_queue(bdev); |
d93ba7a5 | 225 | |
9f9ee1f2 MP |
226 | if (discard && blk_queue_discard(q) && q->limits.discard_zeroes_data && |
227 | blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask, 0) == 0) | |
228 | return 0; | |
d93ba7a5 | 229 | |
9f9ee1f2 MP |
230 | if (bdev_write_same(bdev) && |
231 | blkdev_issue_write_same(bdev, sector, nr_sects, gfp_mask, | |
232 | ZERO_PAGE(0)) == 0) | |
233 | return 0; | |
579e8f3c MP |
234 | |
235 | return __blkdev_issue_zeroout(bdev, sector, nr_sects, gfp_mask); | |
236 | } | |
3f14d792 | 237 | EXPORT_SYMBOL(blkdev_issue_zeroout); |