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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
12struct bio_batch {
13 atomic_t done;
14 unsigned long flags;
15 struct completion *wait;
16};
17
18static void bio_batch_end_io(struct bio *bio, int err)
19{
20 struct bio_batch *bb = bio->bi_private;
21
22 if (err && (err != -EOPNOTSUPP))
23 clear_bit(BIO_UPTODATE, &bb->flags);
24 if (atomic_dec_and_test(&bb->done))
25 complete(bb->wait);
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 */
40int 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);
45 int type = REQ_WRITE | REQ_DISCARD;
46 unsigned int max_discard_sectors;
47 struct bio_batch bb;
48 struct bio *bio;
49 int ret = 0;
50
51 if (!q)
52 return -ENXIO;
53
54 if (!blk_queue_discard(q))
55 return -EOPNOTSUPP;
56
57 /*
58 * Ensure that max_discard_sectors is of the proper
59 * granularity
60 */
61 max_discard_sectors = min(q->limits.max_discard_sectors, UINT_MAX >> 9);
62 if (unlikely(!max_discard_sectors)) {
63 /* Avoid infinite loop below. Being cautious never hurts. */
64 return -EOPNOTSUPP;
65 } else if (q->limits.discard_granularity) {
66 unsigned int disc_sects = q->limits.discard_granularity >> 9;
67
68 max_discard_sectors &= ~(disc_sects - 1);
69 }
70
71 if (flags & BLKDEV_DISCARD_SECURE) {
72 if (!blk_queue_secdiscard(q))
73 return -EOPNOTSUPP;
74 type |= REQ_SECURE;
75 }
76
77 atomic_set(&bb.done, 1);
78 bb.flags = 1 << BIO_UPTODATE;
79 bb.wait = &wait;
80
81 while (nr_sects) {
82 bio = bio_alloc(gfp_mask, 1);
83 if (!bio) {
84 ret = -ENOMEM;
85 break;
86 }
87
88 bio->bi_sector = sector;
89 bio->bi_end_io = bio_batch_end_io;
90 bio->bi_bdev = bdev;
91 bio->bi_private = &bb;
92
93 if (nr_sects > max_discard_sectors) {
94 bio->bi_size = max_discard_sectors << 9;
95 nr_sects -= max_discard_sectors;
96 sector += max_discard_sectors;
97 } else {
98 bio->bi_size = nr_sects << 9;
99 nr_sects = 0;
100 }
101
102 atomic_inc(&bb.done);
103 submit_bio(type, bio);
104 }
105
106 /* Wait for bios in-flight */
107 if (!atomic_dec_and_test(&bb.done))
108 wait_for_completion(&wait);
109
110 if (!test_bit(BIO_UPTODATE, &bb.flags))
111 ret = -EIO;
112
113 return ret;
114}
115EXPORT_SYMBOL(blkdev_issue_discard);
116
117/**
118 * blkdev_issue_zeroout - generate number of zero filed write bios
119 * @bdev: blockdev to issue
120 * @sector: start sector
121 * @nr_sects: number of sectors to write
122 * @gfp_mask: memory allocation flags (for bio_alloc)
123 *
124 * Description:
125 * Generate and issue number of bios with zerofiled pages.
126 */
127
128int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
129 sector_t nr_sects, gfp_t gfp_mask)
130{
131 int ret;
132 struct bio *bio;
133 struct bio_batch bb;
134 unsigned int sz;
135 DECLARE_COMPLETION_ONSTACK(wait);
136
137 atomic_set(&bb.done, 1);
138 bb.flags = 1 << BIO_UPTODATE;
139 bb.wait = &wait;
140
141 ret = 0;
142 while (nr_sects != 0) {
143 bio = bio_alloc(gfp_mask,
144 min(nr_sects, (sector_t)BIO_MAX_PAGES));
145 if (!bio) {
146 ret = -ENOMEM;
147 break;
148 }
149
150 bio->bi_sector = sector;
151 bio->bi_bdev = bdev;
152 bio->bi_end_io = bio_batch_end_io;
153 bio->bi_private = &bb;
154
155 while (nr_sects != 0) {
156 sz = min((sector_t) PAGE_SIZE >> 9 , nr_sects);
157 ret = bio_add_page(bio, ZERO_PAGE(0), sz << 9, 0);
158 nr_sects -= ret >> 9;
159 sector += ret >> 9;
160 if (ret < (sz << 9))
161 break;
162 }
163 ret = 0;
164 atomic_inc(&bb.done);
165 submit_bio(WRITE, bio);
166 }
167
168 /* Wait for bios in-flight */
169 if (!atomic_dec_and_test(&bb.done))
170 wait_for_completion(&wait);
171
172 if (!test_bit(BIO_UPTODATE, &bb.flags))
173 /* One of bios in the batch was completed with error.*/
174 ret = -EIO;
175
176 return ret;
177}
178EXPORT_SYMBOL(blkdev_issue_zeroout);
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
12struct bio_batch {
13 atomic_t done;
14 unsigned long flags;
15 struct completion *wait;
16};
17
18static void bio_batch_end_io(struct bio *bio, int err)
19{
20 struct bio_batch *bb = bio->bi_private;
21
22 if (err && (err != -EOPNOTSUPP))
23 clear_bit(BIO_UPTODATE, &bb->flags);
24 if (atomic_dec_and_test(&bb->done))
25 complete(bb->wait);
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 */
40int 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);
45 int type = REQ_WRITE | REQ_DISCARD;
46 unsigned int max_discard_sectors;
47 struct bio_batch bb;
48 struct bio *bio;
49 int ret = 0;
50
51 if (!q)
52 return -ENXIO;
53
54 if (!blk_queue_discard(q))
55 return -EOPNOTSUPP;
56
57 /*
58 * Ensure that max_discard_sectors is of the proper
59 * granularity
60 */
61 max_discard_sectors = min(q->limits.max_discard_sectors, UINT_MAX >> 9);
62 if (unlikely(!max_discard_sectors)) {
63 /* Avoid infinite loop below. Being cautious never hurts. */
64 return -EOPNOTSUPP;
65 } else if (q->limits.discard_granularity) {
66 unsigned int disc_sects = q->limits.discard_granularity >> 9;
67
68 max_discard_sectors &= ~(disc_sects - 1);
69 }
70
71 if (flags & BLKDEV_DISCARD_SECURE) {
72 if (!blk_queue_secdiscard(q))
73 return -EOPNOTSUPP;
74 type |= REQ_SECURE;
75 }
76
77 atomic_set(&bb.done, 1);
78 bb.flags = 1 << BIO_UPTODATE;
79 bb.wait = &wait;
80
81 while (nr_sects) {
82 bio = bio_alloc(gfp_mask, 1);
83 if (!bio) {
84 ret = -ENOMEM;
85 break;
86 }
87
88 bio->bi_sector = sector;
89 bio->bi_end_io = bio_batch_end_io;
90 bio->bi_bdev = bdev;
91 bio->bi_private = &bb;
92
93 if (nr_sects > max_discard_sectors) {
94 bio->bi_size = max_discard_sectors << 9;
95 nr_sects -= max_discard_sectors;
96 sector += max_discard_sectors;
97 } else {
98 bio->bi_size = nr_sects << 9;
99 nr_sects = 0;
100 }
101
102 atomic_inc(&bb.done);
103 submit_bio(type, bio);
104 }
105
106 /* Wait for bios in-flight */
107 if (!atomic_dec_and_test(&bb.done))
108 wait_for_completion(&wait);
109
110 if (!test_bit(BIO_UPTODATE, &bb.flags))
111 ret = -EIO;
112
113 return ret;
114}
115EXPORT_SYMBOL(blkdev_issue_discard);
116
117/**
118 * blkdev_issue_zeroout - generate number of zero filed write bios
119 * @bdev: blockdev to issue
120 * @sector: start sector
121 * @nr_sects: number of sectors to write
122 * @gfp_mask: memory allocation flags (for bio_alloc)
123 *
124 * Description:
125 * Generate and issue number of bios with zerofiled pages.
126 */
127
128int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
129 sector_t nr_sects, gfp_t gfp_mask)
130{
131 int ret;
132 struct bio *bio;
133 struct bio_batch bb;
134 unsigned int sz;
135 DECLARE_COMPLETION_ONSTACK(wait);
136
137 atomic_set(&bb.done, 1);
138 bb.flags = 1 << BIO_UPTODATE;
139 bb.wait = &wait;
140
141 ret = 0;
142 while (nr_sects != 0) {
143 bio = bio_alloc(gfp_mask,
144 min(nr_sects, (sector_t)BIO_MAX_PAGES));
145 if (!bio) {
146 ret = -ENOMEM;
147 break;
148 }
149
150 bio->bi_sector = sector;
151 bio->bi_bdev = bdev;
152 bio->bi_end_io = bio_batch_end_io;
153 bio->bi_private = &bb;
154
155 while (nr_sects != 0) {
156 sz = min((sector_t) PAGE_SIZE >> 9 , nr_sects);
157 ret = bio_add_page(bio, ZERO_PAGE(0), sz << 9, 0);
158 nr_sects -= ret >> 9;
159 sector += ret >> 9;
160 if (ret < (sz << 9))
161 break;
162 }
163 ret = 0;
164 atomic_inc(&bb.done);
165 submit_bio(WRITE, bio);
166 }
167
168 /* Wait for bios in-flight */
169 if (!atomic_dec_and_test(&bb.done))
170 wait_for_completion(&wait);
171
172 if (!test_bit(BIO_UPTODATE, &bb.flags))
173 /* One of bios in the batch was completed with error.*/
174 ret = -EIO;
175
176 return ret;
177}
178EXPORT_SYMBOL(blkdev_issue_zeroout);