Loading...
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 int error;
15 struct completion *wait;
16};
17
18static void bio_batch_end_io(struct bio *bio)
19{
20 struct bio_batch *bb = bio->bi_private;
21
22 if (bio->bi_error && bio->bi_error != -EOPNOTSUPP)
23 bb->error = bio->bi_error;
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 granularity;
47 int alignment;
48 struct bio_batch bb;
49 struct bio *bio;
50 int ret = 0;
51 struct blk_plug plug;
52
53 if (!q)
54 return -ENXIO;
55
56 if (!blk_queue_discard(q))
57 return -EOPNOTSUPP;
58
59 /* Zero-sector (unknown) and one-sector granularities are the same. */
60 granularity = max(q->limits.discard_granularity >> 9, 1U);
61 alignment = (bdev_discard_alignment(bdev) >> 9) % granularity;
62
63 if (flags & BLKDEV_DISCARD_SECURE) {
64 if (!blk_queue_secdiscard(q))
65 return -EOPNOTSUPP;
66 type |= REQ_SECURE;
67 }
68
69 atomic_set(&bb.done, 1);
70 bb.error = 0;
71 bb.wait = &wait;
72
73 blk_start_plug(&plug);
74 while (nr_sects) {
75 unsigned int req_sects;
76 sector_t end_sect, tmp;
77
78 bio = bio_alloc(gfp_mask, 1);
79 if (!bio) {
80 ret = -ENOMEM;
81 break;
82 }
83
84 /* Make sure bi_size doesn't overflow */
85 req_sects = min_t(sector_t, nr_sects, UINT_MAX >> 9);
86
87 /*
88 * If splitting a request, and the next starting sector would be
89 * misaligned, stop the discard at the previous aligned sector.
90 */
91 end_sect = sector + req_sects;
92 tmp = end_sect;
93 if (req_sects < nr_sects &&
94 sector_div(tmp, granularity) != alignment) {
95 end_sect = end_sect - alignment;
96 sector_div(end_sect, granularity);
97 end_sect = end_sect * granularity + alignment;
98 req_sects = end_sect - sector;
99 }
100
101 bio->bi_iter.bi_sector = sector;
102 bio->bi_end_io = bio_batch_end_io;
103 bio->bi_bdev = bdev;
104 bio->bi_private = &bb;
105
106 bio->bi_iter.bi_size = req_sects << 9;
107 nr_sects -= req_sects;
108 sector = end_sect;
109
110 atomic_inc(&bb.done);
111 submit_bio(type, bio);
112
113 /*
114 * We can loop for a long time in here, if someone does
115 * full device discards (like mkfs). Be nice and allow
116 * us to schedule out to avoid softlocking if preempt
117 * is disabled.
118 */
119 cond_resched();
120 }
121 blk_finish_plug(&plug);
122
123 /* Wait for bios in-flight */
124 if (!atomic_dec_and_test(&bb.done))
125 wait_for_completion_io(&wait);
126
127 if (bb.error)
128 return bb.error;
129 return ret;
130}
131EXPORT_SYMBOL(blkdev_issue_discard);
132
133/**
134 * blkdev_issue_write_same - queue a write same operation
135 * @bdev: target blockdev
136 * @sector: start sector
137 * @nr_sects: number of sectors to write
138 * @gfp_mask: memory allocation flags (for bio_alloc)
139 * @page: page containing data to write
140 *
141 * Description:
142 * Issue a write same request for the sectors in question.
143 */
144int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
145 sector_t nr_sects, gfp_t gfp_mask,
146 struct page *page)
147{
148 DECLARE_COMPLETION_ONSTACK(wait);
149 struct request_queue *q = bdev_get_queue(bdev);
150 unsigned int max_write_same_sectors;
151 struct bio_batch bb;
152 struct bio *bio;
153 int ret = 0;
154
155 if (!q)
156 return -ENXIO;
157
158 /* Ensure that max_write_same_sectors doesn't overflow bi_size */
159 max_write_same_sectors = UINT_MAX >> 9;
160
161 atomic_set(&bb.done, 1);
162 bb.error = 0;
163 bb.wait = &wait;
164
165 while (nr_sects) {
166 bio = bio_alloc(gfp_mask, 1);
167 if (!bio) {
168 ret = -ENOMEM;
169 break;
170 }
171
172 bio->bi_iter.bi_sector = sector;
173 bio->bi_end_io = bio_batch_end_io;
174 bio->bi_bdev = bdev;
175 bio->bi_private = &bb;
176 bio->bi_vcnt = 1;
177 bio->bi_io_vec->bv_page = page;
178 bio->bi_io_vec->bv_offset = 0;
179 bio->bi_io_vec->bv_len = bdev_logical_block_size(bdev);
180
181 if (nr_sects > max_write_same_sectors) {
182 bio->bi_iter.bi_size = max_write_same_sectors << 9;
183 nr_sects -= max_write_same_sectors;
184 sector += max_write_same_sectors;
185 } else {
186 bio->bi_iter.bi_size = nr_sects << 9;
187 nr_sects = 0;
188 }
189
190 atomic_inc(&bb.done);
191 submit_bio(REQ_WRITE | REQ_WRITE_SAME, bio);
192 }
193
194 /* Wait for bios in-flight */
195 if (!atomic_dec_and_test(&bb.done))
196 wait_for_completion_io(&wait);
197
198 if (bb.error)
199 return bb.error;
200 return ret;
201}
202EXPORT_SYMBOL(blkdev_issue_write_same);
203
204/**
205 * blkdev_issue_zeroout - generate number of zero filed write bios
206 * @bdev: blockdev to issue
207 * @sector: start sector
208 * @nr_sects: number of sectors to write
209 * @gfp_mask: memory allocation flags (for bio_alloc)
210 *
211 * Description:
212 * Generate and issue number of bios with zerofiled pages.
213 */
214
215static int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
216 sector_t nr_sects, gfp_t gfp_mask)
217{
218 int ret;
219 struct bio *bio;
220 struct bio_batch bb;
221 unsigned int sz;
222 DECLARE_COMPLETION_ONSTACK(wait);
223
224 atomic_set(&bb.done, 1);
225 bb.error = 0;
226 bb.wait = &wait;
227
228 ret = 0;
229 while (nr_sects != 0) {
230 bio = bio_alloc(gfp_mask,
231 min(nr_sects, (sector_t)BIO_MAX_PAGES));
232 if (!bio) {
233 ret = -ENOMEM;
234 break;
235 }
236
237 bio->bi_iter.bi_sector = sector;
238 bio->bi_bdev = bdev;
239 bio->bi_end_io = bio_batch_end_io;
240 bio->bi_private = &bb;
241
242 while (nr_sects != 0) {
243 sz = min((sector_t) PAGE_SIZE >> 9 , nr_sects);
244 ret = bio_add_page(bio, ZERO_PAGE(0), sz << 9, 0);
245 nr_sects -= ret >> 9;
246 sector += ret >> 9;
247 if (ret < (sz << 9))
248 break;
249 }
250 ret = 0;
251 atomic_inc(&bb.done);
252 submit_bio(WRITE, bio);
253 }
254
255 /* Wait for bios in-flight */
256 if (!atomic_dec_and_test(&bb.done))
257 wait_for_completion_io(&wait);
258
259 if (bb.error)
260 return bb.error;
261 return ret;
262}
263
264/**
265 * blkdev_issue_zeroout - zero-fill a block range
266 * @bdev: blockdev to write
267 * @sector: start sector
268 * @nr_sects: number of sectors to write
269 * @gfp_mask: memory allocation flags (for bio_alloc)
270 * @discard: whether to discard the block range
271 *
272 * Description:
273 * Zero-fill a block range. If the discard flag is set and the block
274 * device guarantees that subsequent READ operations to the block range
275 * in question will return zeroes, the blocks will be discarded. Should
276 * the discard request fail, if the discard flag is not set, or if
277 * discard_zeroes_data is not supported, this function will resort to
278 * zeroing the blocks manually, thus provisioning (allocating,
279 * anchoring) them. If the block device supports the WRITE SAME command
280 * blkdev_issue_zeroout() will use it to optimize the process of
281 * clearing the block range. Otherwise the zeroing will be performed
282 * using regular WRITE calls.
283 */
284
285int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
286 sector_t nr_sects, gfp_t gfp_mask, bool discard)
287{
288 struct request_queue *q = bdev_get_queue(bdev);
289
290 if (discard && blk_queue_discard(q) && q->limits.discard_zeroes_data &&
291 blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask, 0) == 0)
292 return 0;
293
294 if (bdev_write_same(bdev) &&
295 blkdev_issue_write_same(bdev, sector, nr_sects, gfp_mask,
296 ZERO_PAGE(0)) == 0)
297 return 0;
298
299 return __blkdev_issue_zeroout(bdev, sector, nr_sects, gfp_mask);
300}
301EXPORT_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, granularity;
47 int alignment;
48 struct bio_batch bb;
49 struct bio *bio;
50 int ret = 0;
51 struct blk_plug plug;
52
53 if (!q)
54 return -ENXIO;
55
56 if (!blk_queue_discard(q))
57 return -EOPNOTSUPP;
58
59 /* Zero-sector (unknown) and one-sector granularities are the same. */
60 granularity = max(q->limits.discard_granularity >> 9, 1U);
61 alignment = (bdev_discard_alignment(bdev) >> 9) % granularity;
62
63 /*
64 * Ensure that max_discard_sectors is of the proper
65 * granularity, so that requests stay aligned after a split.
66 */
67 max_discard_sectors = min(q->limits.max_discard_sectors, UINT_MAX >> 9);
68 max_discard_sectors -= max_discard_sectors % granularity;
69 if (unlikely(!max_discard_sectors)) {
70 /* Avoid infinite loop below. Being cautious never hurts. */
71 return -EOPNOTSUPP;
72 }
73
74 if (flags & BLKDEV_DISCARD_SECURE) {
75 if (!blk_queue_secdiscard(q))
76 return -EOPNOTSUPP;
77 type |= REQ_SECURE;
78 }
79
80 atomic_set(&bb.done, 1);
81 bb.flags = 1 << BIO_UPTODATE;
82 bb.wait = &wait;
83
84 blk_start_plug(&plug);
85 while (nr_sects) {
86 unsigned int req_sects;
87 sector_t end_sect, tmp;
88
89 bio = bio_alloc(gfp_mask, 1);
90 if (!bio) {
91 ret = -ENOMEM;
92 break;
93 }
94
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;
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;
108 req_sects = end_sect - sector;
109 }
110
111 bio->bi_iter.bi_sector = sector;
112 bio->bi_end_io = bio_batch_end_io;
113 bio->bi_bdev = bdev;
114 bio->bi_private = &bb;
115
116 bio->bi_iter.bi_size = req_sects << 9;
117 nr_sects -= req_sects;
118 sector = end_sect;
119
120 atomic_inc(&bb.done);
121 submit_bio(type, bio);
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();
130 }
131 blk_finish_plug(&plug);
132
133 /* Wait for bios in-flight */
134 if (!atomic_dec_and_test(&bb.done))
135 wait_for_completion_io(&wait);
136
137 if (!test_bit(BIO_UPTODATE, &bb.flags))
138 ret = -EIO;
139
140 return ret;
141}
142EXPORT_SYMBOL(blkdev_issue_discard);
143
144/**
145 * blkdev_issue_write_same - queue a write same operation
146 * @bdev: target blockdev
147 * @sector: start sector
148 * @nr_sects: number of sectors to write
149 * @gfp_mask: memory allocation flags (for bio_alloc)
150 * @page: page containing data to write
151 *
152 * Description:
153 * Issue a write same request for the sectors in question.
154 */
155int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
156 sector_t nr_sects, gfp_t gfp_mask,
157 struct page *page)
158{
159 DECLARE_COMPLETION_ONSTACK(wait);
160 struct request_queue *q = bdev_get_queue(bdev);
161 unsigned int max_write_same_sectors;
162 struct bio_batch bb;
163 struct bio *bio;
164 int ret = 0;
165
166 if (!q)
167 return -ENXIO;
168
169 max_write_same_sectors = q->limits.max_write_same_sectors;
170
171 if (max_write_same_sectors == 0)
172 return -EOPNOTSUPP;
173
174 atomic_set(&bb.done, 1);
175 bb.flags = 1 << BIO_UPTODATE;
176 bb.wait = &wait;
177
178 while (nr_sects) {
179 bio = bio_alloc(gfp_mask, 1);
180 if (!bio) {
181 ret = -ENOMEM;
182 break;
183 }
184
185 bio->bi_iter.bi_sector = sector;
186 bio->bi_end_io = bio_batch_end_io;
187 bio->bi_bdev = bdev;
188 bio->bi_private = &bb;
189 bio->bi_vcnt = 1;
190 bio->bi_io_vec->bv_page = page;
191 bio->bi_io_vec->bv_offset = 0;
192 bio->bi_io_vec->bv_len = bdev_logical_block_size(bdev);
193
194 if (nr_sects > max_write_same_sectors) {
195 bio->bi_iter.bi_size = max_write_same_sectors << 9;
196 nr_sects -= max_write_same_sectors;
197 sector += max_write_same_sectors;
198 } else {
199 bio->bi_iter.bi_size = nr_sects << 9;
200 nr_sects = 0;
201 }
202
203 atomic_inc(&bb.done);
204 submit_bio(REQ_WRITE | REQ_WRITE_SAME, bio);
205 }
206
207 /* Wait for bios in-flight */
208 if (!atomic_dec_and_test(&bb.done))
209 wait_for_completion_io(&wait);
210
211 if (!test_bit(BIO_UPTODATE, &bb.flags))
212 ret = -ENOTSUPP;
213
214 return ret;
215}
216EXPORT_SYMBOL(blkdev_issue_write_same);
217
218/**
219 * blkdev_issue_zeroout - generate number of zero filed write bios
220 * @bdev: blockdev to issue
221 * @sector: start sector
222 * @nr_sects: number of sectors to write
223 * @gfp_mask: memory allocation flags (for bio_alloc)
224 *
225 * Description:
226 * Generate and issue number of bios with zerofiled pages.
227 */
228
229int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
230 sector_t nr_sects, gfp_t gfp_mask)
231{
232 int ret;
233 struct bio *bio;
234 struct bio_batch bb;
235 unsigned int sz;
236 DECLARE_COMPLETION_ONSTACK(wait);
237
238 atomic_set(&bb.done, 1);
239 bb.flags = 1 << BIO_UPTODATE;
240 bb.wait = &wait;
241
242 ret = 0;
243 while (nr_sects != 0) {
244 bio = bio_alloc(gfp_mask,
245 min(nr_sects, (sector_t)BIO_MAX_PAGES));
246 if (!bio) {
247 ret = -ENOMEM;
248 break;
249 }
250
251 bio->bi_iter.bi_sector = sector;
252 bio->bi_bdev = bdev;
253 bio->bi_end_io = bio_batch_end_io;
254 bio->bi_private = &bb;
255
256 while (nr_sects != 0) {
257 sz = min((sector_t) PAGE_SIZE >> 9 , nr_sects);
258 ret = bio_add_page(bio, ZERO_PAGE(0), sz << 9, 0);
259 nr_sects -= ret >> 9;
260 sector += ret >> 9;
261 if (ret < (sz << 9))
262 break;
263 }
264 ret = 0;
265 atomic_inc(&bb.done);
266 submit_bio(WRITE, bio);
267 }
268
269 /* Wait for bios in-flight */
270 if (!atomic_dec_and_test(&bb.done))
271 wait_for_completion_io(&wait);
272
273 if (!test_bit(BIO_UPTODATE, &bb.flags))
274 /* One of bios in the batch was completed with error.*/
275 ret = -EIO;
276
277 return ret;
278}
279
280/**
281 * blkdev_issue_zeroout - zero-fill a block range
282 * @bdev: blockdev to write
283 * @sector: start sector
284 * @nr_sects: number of sectors to write
285 * @gfp_mask: memory allocation flags (for bio_alloc)
286 *
287 * Description:
288 * Generate and issue number of bios with zerofiled pages.
289 */
290
291int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
292 sector_t nr_sects, gfp_t gfp_mask)
293{
294 if (bdev_write_same(bdev)) {
295 unsigned char bdn[BDEVNAME_SIZE];
296
297 if (!blkdev_issue_write_same(bdev, sector, nr_sects, gfp_mask,
298 ZERO_PAGE(0)))
299 return 0;
300
301 bdevname(bdev, bdn);
302 pr_err("%s: WRITE SAME failed. Manually zeroing.\n", bdn);
303 }
304
305 return __blkdev_issue_zeroout(bdev, sector, nr_sects, gfp_mask);
306}
307EXPORT_SYMBOL(blkdev_issue_zeroout);