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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 | ||
12 | static void blkdev_discard_end_io(struct bio *bio, int err) | |
13 | { | |
14 | if (err) { | |
15 | if (err == -EOPNOTSUPP) | |
16 | set_bit(BIO_EOPNOTSUPP, &bio->bi_flags); | |
17 | clear_bit(BIO_UPTODATE, &bio->bi_flags); | |
18 | } | |
19 | ||
20 | if (bio->bi_private) | |
21 | complete(bio->bi_private); | |
f31e7e40 DM |
22 | |
23 | bio_put(bio); | |
24 | } | |
25 | ||
26 | /** | |
27 | * blkdev_issue_discard - queue a discard | |
28 | * @bdev: blockdev to issue discard for | |
29 | * @sector: start sector | |
30 | * @nr_sects: number of sectors to discard | |
31 | * @gfp_mask: memory allocation flags (for bio_alloc) | |
32 | * @flags: BLKDEV_IFL_* flags to control behaviour | |
33 | * | |
34 | * Description: | |
35 | * Issue a discard request for the sectors in question. | |
36 | */ | |
37 | int blkdev_issue_discard(struct block_device *bdev, sector_t sector, | |
38 | sector_t nr_sects, gfp_t gfp_mask, unsigned long flags) | |
39 | { | |
40 | DECLARE_COMPLETION_ONSTACK(wait); | |
41 | struct request_queue *q = bdev_get_queue(bdev); | |
42 | int type = flags & BLKDEV_IFL_BARRIER ? | |
43 | DISCARD_BARRIER : DISCARD_NOBARRIER; | |
10d1f9e2 | 44 | unsigned int max_discard_sectors; |
f31e7e40 | 45 | struct bio *bio; |
f31e7e40 DM |
46 | int ret = 0; |
47 | ||
48 | if (!q) | |
49 | return -ENXIO; | |
50 | ||
51 | if (!blk_queue_discard(q)) | |
52 | return -EOPNOTSUPP; | |
53 | ||
10d1f9e2 JA |
54 | /* |
55 | * Ensure that max_discard_sectors is of the proper | |
56 | * granularity | |
57 | */ | |
58 | max_discard_sectors = min(q->limits.max_discard_sectors, UINT_MAX >> 9); | |
59 | if (q->limits.discard_granularity) { | |
60 | unsigned int disc_sects = q->limits.discard_granularity >> 9; | |
61 | ||
62 | max_discard_sectors &= ~(disc_sects - 1); | |
63 | } | |
f31e7e40 | 64 | |
10d1f9e2 | 65 | while (nr_sects && !ret) { |
f31e7e40 | 66 | bio = bio_alloc(gfp_mask, 1); |
66ac0280 CH |
67 | if (!bio) { |
68 | ret = -ENOMEM; | |
69 | break; | |
70 | } | |
71 | ||
f31e7e40 DM |
72 | bio->bi_sector = sector; |
73 | bio->bi_end_io = blkdev_discard_end_io; | |
74 | bio->bi_bdev = bdev; | |
75 | if (flags & BLKDEV_IFL_WAIT) | |
76 | bio->bi_private = &wait; | |
77 | ||
f31e7e40 DM |
78 | if (nr_sects > max_discard_sectors) { |
79 | bio->bi_size = max_discard_sectors << 9; | |
80 | nr_sects -= max_discard_sectors; | |
81 | sector += max_discard_sectors; | |
82 | } else { | |
83 | bio->bi_size = nr_sects << 9; | |
84 | nr_sects = 0; | |
85 | } | |
86 | ||
87 | bio_get(bio); | |
88 | submit_bio(type, bio); | |
89 | ||
90 | if (flags & BLKDEV_IFL_WAIT) | |
91 | wait_for_completion(&wait); | |
92 | ||
93 | if (bio_flagged(bio, BIO_EOPNOTSUPP)) | |
94 | ret = -EOPNOTSUPP; | |
95 | else if (!bio_flagged(bio, BIO_UPTODATE)) | |
96 | ret = -EIO; | |
97 | bio_put(bio); | |
98 | } | |
66ac0280 | 99 | |
f31e7e40 | 100 | return ret; |
f31e7e40 DM |
101 | } |
102 | EXPORT_SYMBOL(blkdev_issue_discard); | |
3f14d792 DM |
103 | |
104 | struct bio_batch | |
105 | { | |
106 | atomic_t done; | |
107 | unsigned long flags; | |
108 | struct completion *wait; | |
109 | bio_end_io_t *end_io; | |
110 | }; | |
111 | ||
112 | static void bio_batch_end_io(struct bio *bio, int err) | |
113 | { | |
114 | struct bio_batch *bb = bio->bi_private; | |
0341aafb | 115 | |
3f14d792 DM |
116 | if (err) { |
117 | if (err == -EOPNOTSUPP) | |
118 | set_bit(BIO_EOPNOTSUPP, &bb->flags); | |
119 | else | |
120 | clear_bit(BIO_UPTODATE, &bb->flags); | |
121 | } | |
122 | if (bb) { | |
123 | if (bb->end_io) | |
124 | bb->end_io(bio, err); | |
125 | atomic_inc(&bb->done); | |
126 | complete(bb->wait); | |
127 | } | |
128 | bio_put(bio); | |
129 | } | |
130 | ||
131 | /** | |
132 | * blkdev_issue_zeroout generate number of zero filed write bios | |
133 | * @bdev: blockdev to issue | |
134 | * @sector: start sector | |
135 | * @nr_sects: number of sectors to write | |
136 | * @gfp_mask: memory allocation flags (for bio_alloc) | |
137 | * @flags: BLKDEV_IFL_* flags to control behaviour | |
138 | * | |
139 | * Description: | |
140 | * Generate and issue number of bios with zerofiled pages. | |
141 | * Send barrier at the beginning and at the end if requested. This guarantie | |
142 | * correct request ordering. Empty barrier allow us to avoid post queue flush. | |
143 | */ | |
144 | ||
145 | int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, | |
146 | sector_t nr_sects, gfp_t gfp_mask, unsigned long flags) | |
147 | { | |
18edc8ea | 148 | int ret; |
3f14d792 DM |
149 | struct bio *bio; |
150 | struct bio_batch bb; | |
151 | unsigned int sz, issued = 0; | |
152 | DECLARE_COMPLETION_ONSTACK(wait); | |
153 | ||
154 | atomic_set(&bb.done, 0); | |
155 | bb.flags = 1 << BIO_UPTODATE; | |
156 | bb.wait = &wait; | |
157 | bb.end_io = NULL; | |
158 | ||
159 | if (flags & BLKDEV_IFL_BARRIER) { | |
160 | /* issue async barrier before the data */ | |
161 | ret = blkdev_issue_flush(bdev, gfp_mask, NULL, 0); | |
162 | if (ret) | |
163 | return ret; | |
164 | } | |
165 | submit: | |
18edc8ea | 166 | ret = 0; |
3f14d792 DM |
167 | while (nr_sects != 0) { |
168 | bio = bio_alloc(gfp_mask, | |
169 | min(nr_sects, (sector_t)BIO_MAX_PAGES)); | |
18edc8ea DM |
170 | if (!bio) { |
171 | ret = -ENOMEM; | |
3f14d792 | 172 | break; |
18edc8ea | 173 | } |
3f14d792 DM |
174 | |
175 | bio->bi_sector = sector; | |
176 | bio->bi_bdev = bdev; | |
177 | bio->bi_end_io = bio_batch_end_io; | |
178 | if (flags & BLKDEV_IFL_WAIT) | |
179 | bio->bi_private = &bb; | |
180 | ||
0341aafb JA |
181 | while (nr_sects != 0) { |
182 | sz = min((sector_t) PAGE_SIZE >> 9 , nr_sects); | |
3f14d792 DM |
183 | if (sz == 0) |
184 | /* bio has maximum size possible */ | |
185 | break; | |
186 | ret = bio_add_page(bio, ZERO_PAGE(0), sz << 9, 0); | |
187 | nr_sects -= ret >> 9; | |
188 | sector += ret >> 9; | |
189 | if (ret < (sz << 9)) | |
190 | break; | |
191 | } | |
18edc8ea | 192 | ret = 0; |
3f14d792 DM |
193 | issued++; |
194 | submit_bio(WRITE, bio); | |
195 | } | |
196 | /* | |
197 | * When all data bios are in flight. Send final barrier if requeted. | |
198 | */ | |
199 | if (nr_sects == 0 && flags & BLKDEV_IFL_BARRIER) | |
200 | ret = blkdev_issue_flush(bdev, gfp_mask, NULL, | |
201 | flags & BLKDEV_IFL_WAIT); | |
202 | ||
203 | ||
204 | if (flags & BLKDEV_IFL_WAIT) | |
205 | /* Wait for bios in-flight */ | |
206 | while ( issued != atomic_read(&bb.done)) | |
207 | wait_for_completion(&wait); | |
208 | ||
209 | if (!test_bit(BIO_UPTODATE, &bb.flags)) | |
210 | /* One of bios in the batch was completed with error.*/ | |
211 | ret = -EIO; | |
212 | ||
213 | if (ret) | |
214 | goto out; | |
215 | ||
216 | if (test_bit(BIO_EOPNOTSUPP, &bb.flags)) { | |
217 | ret = -EOPNOTSUPP; | |
218 | goto out; | |
219 | } | |
220 | if (nr_sects != 0) | |
221 | goto submit; | |
222 | out: | |
223 | return ret; | |
224 | } | |
225 | EXPORT_SYMBOL(blkdev_issue_zeroout); |