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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); | |
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 = REQ_WRITE | REQ_DISCARD; | |
43 | unsigned int max_discard_sectors; | |
44 | struct bio *bio; | |
45 | int ret = 0; | |
46 | ||
47 | if (!q) | |
48 | return -ENXIO; | |
49 | ||
50 | if (!blk_queue_discard(q)) | |
51 | return -EOPNOTSUPP; | |
52 | ||
53 | /* | |
54 | * Ensure that max_discard_sectors is of the proper | |
55 | * granularity | |
56 | */ | |
57 | max_discard_sectors = min(q->limits.max_discard_sectors, UINT_MAX >> 9); | |
58 | if (q->limits.discard_granularity) { | |
59 | unsigned int disc_sects = q->limits.discard_granularity >> 9; | |
60 | ||
61 | max_discard_sectors &= ~(disc_sects - 1); | |
62 | } | |
63 | ||
64 | if (flags & BLKDEV_DISCARD_SECURE) { | |
65 | if (!blk_queue_secdiscard(q)) | |
66 | return -EOPNOTSUPP; | |
67 | type |= REQ_SECURE; | |
68 | } | |
69 | ||
70 | while (nr_sects && !ret) { | |
71 | bio = bio_alloc(gfp_mask, 1); | |
72 | if (!bio) { | |
73 | ret = -ENOMEM; | |
74 | break; | |
75 | } | |
76 | ||
77 | bio->bi_sector = sector; | |
78 | bio->bi_end_io = blkdev_discard_end_io; | |
79 | bio->bi_bdev = bdev; | |
80 | bio->bi_private = &wait; | |
81 | ||
82 | if (nr_sects > max_discard_sectors) { | |
83 | bio->bi_size = max_discard_sectors << 9; | |
84 | nr_sects -= max_discard_sectors; | |
85 | sector += max_discard_sectors; | |
86 | } else { | |
87 | bio->bi_size = nr_sects << 9; | |
88 | nr_sects = 0; | |
89 | } | |
90 | ||
91 | bio_get(bio); | |
92 | submit_bio(type, bio); | |
93 | ||
94 | wait_for_completion(&wait); | |
95 | ||
96 | if (bio_flagged(bio, BIO_EOPNOTSUPP)) | |
97 | ret = -EOPNOTSUPP; | |
98 | else if (!bio_flagged(bio, BIO_UPTODATE)) | |
99 | ret = -EIO; | |
100 | bio_put(bio); | |
101 | } | |
102 | ||
103 | return ret; | |
104 | } | |
105 | EXPORT_SYMBOL(blkdev_issue_discard); | |
106 | ||
107 | struct bio_batch | |
108 | { | |
109 | atomic_t done; | |
110 | unsigned long flags; | |
111 | struct completion *wait; | |
112 | bio_end_io_t *end_io; | |
113 | }; | |
114 | ||
115 | static void bio_batch_end_io(struct bio *bio, int err) | |
116 | { | |
117 | struct bio_batch *bb = bio->bi_private; | |
118 | ||
119 | if (err) { | |
120 | if (err == -EOPNOTSUPP) | |
121 | set_bit(BIO_EOPNOTSUPP, &bb->flags); | |
122 | else | |
123 | clear_bit(BIO_UPTODATE, &bb->flags); | |
124 | } | |
125 | if (bb) { | |
126 | if (bb->end_io) | |
127 | bb->end_io(bio, err); | |
128 | atomic_inc(&bb->done); | |
129 | complete(bb->wait); | |
130 | } | |
131 | bio_put(bio); | |
132 | } | |
133 | ||
134 | /** | |
135 | * blkdev_issue_zeroout generate number of zero filed write bios | |
136 | * @bdev: blockdev to issue | |
137 | * @sector: start sector | |
138 | * @nr_sects: number of sectors to write | |
139 | * @gfp_mask: memory allocation flags (for bio_alloc) | |
140 | * | |
141 | * Description: | |
142 | * Generate and issue number of bios with zerofiled pages. | |
143 | * Send barrier at the beginning and at the end if requested. This guarantie | |
144 | * correct request ordering. Empty barrier allow us to avoid post queue flush. | |
145 | */ | |
146 | ||
147 | int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, | |
148 | sector_t nr_sects, gfp_t gfp_mask) | |
149 | { | |
150 | int ret; | |
151 | struct bio *bio; | |
152 | struct bio_batch bb; | |
153 | unsigned int sz, issued = 0; | |
154 | DECLARE_COMPLETION_ONSTACK(wait); | |
155 | ||
156 | atomic_set(&bb.done, 0); | |
157 | bb.flags = 1 << BIO_UPTODATE; | |
158 | bb.wait = &wait; | |
159 | bb.end_io = NULL; | |
160 | ||
161 | submit: | |
162 | ret = 0; | |
163 | while (nr_sects != 0) { | |
164 | bio = bio_alloc(gfp_mask, | |
165 | min(nr_sects, (sector_t)BIO_MAX_PAGES)); | |
166 | if (!bio) { | |
167 | ret = -ENOMEM; | |
168 | break; | |
169 | } | |
170 | ||
171 | bio->bi_sector = sector; | |
172 | bio->bi_bdev = bdev; | |
173 | bio->bi_end_io = bio_batch_end_io; | |
174 | bio->bi_private = &bb; | |
175 | ||
176 | while (nr_sects != 0) { | |
177 | sz = min((sector_t) PAGE_SIZE >> 9 , nr_sects); | |
178 | if (sz == 0) | |
179 | /* bio has maximum size possible */ | |
180 | break; | |
181 | ret = bio_add_page(bio, ZERO_PAGE(0), sz << 9, 0); | |
182 | nr_sects -= ret >> 9; | |
183 | sector += ret >> 9; | |
184 | if (ret < (sz << 9)) | |
185 | break; | |
186 | } | |
187 | ret = 0; | |
188 | issued++; | |
189 | submit_bio(WRITE, bio); | |
190 | } | |
191 | ||
192 | /* Wait for bios in-flight */ | |
193 | while (issued != atomic_read(&bb.done)) | |
194 | wait_for_completion(&wait); | |
195 | ||
196 | if (!test_bit(BIO_UPTODATE, &bb.flags)) | |
197 | /* One of bios in the batch was completed with error.*/ | |
198 | ret = -EIO; | |
199 | ||
200 | if (ret) | |
201 | goto out; | |
202 | ||
203 | if (test_bit(BIO_EOPNOTSUPP, &bb.flags)) { | |
204 | ret = -EOPNOTSUPP; | |
205 | goto out; | |
206 | } | |
207 | if (nr_sects != 0) | |
208 | goto submit; | |
209 | out: | |
210 | return ret; | |
211 | } | |
212 | EXPORT_SYMBOL(blkdev_issue_zeroout); |