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Dmitry Monakhovf31e7e42010-04-28 17:55:08 +04001/*
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
Lukas Czerner5dba3082011-05-06 19:26:27 -060012struct 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)
Dmitry Monakhovf31e7e42010-04-28 17:55:08 +040019{
Lukas Czerner5dba3082011-05-06 19:26:27 -060020 struct bio_batch *bb = bio->bi_private;
21
Lukas Czerner8af19542011-05-06 19:30:01 -060022 if (err && (err != -EOPNOTSUPP))
Lukas Czerner5dba3082011-05-06 19:26:27 -060023 clear_bit(BIO_UPTODATE, &bb->flags);
Lukas Czerner5dba3082011-05-06 19:26:27 -060024 if (atomic_dec_and_test(&bb->done))
25 complete(bb->wait);
Dmitry Monakhovf31e7e42010-04-28 17:55:08 +040026 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);
Christoph Hellwig8c555362010-08-18 05:29:22 -040045 int type = REQ_WRITE | REQ_DISCARD;
Geert Uytterhoeven97597dc2013-11-04 14:00:06 +010046 unsigned int max_discard_sectors, granularity;
47 int alignment;
Lukas Czerner5dba3082011-05-06 19:26:27 -060048 struct bio_batch bb;
Dmitry Monakhovf31e7e42010-04-28 17:55:08 +040049 struct bio *bio;
Dmitry Monakhovf31e7e42010-04-28 17:55:08 +040050 int ret = 0;
Shaohua Li0cfbcaf2012-12-14 11:15:51 +080051 struct blk_plug plug;
Dmitry Monakhovf31e7e42010-04-28 17:55:08 +040052
53 if (!q)
54 return -ENXIO;
55
56 if (!blk_queue_discard(q))
57 return -EOPNOTSUPP;
58
Paolo Bonzinif6ff53d2012-08-02 09:48:49 +020059 /* Zero-sector (unknown) and one-sector granularities are the same. */
60 granularity = max(q->limits.discard_granularity >> 9, 1U);
Geert Uytterhoeven97597dc2013-11-04 14:00:06 +010061 alignment = (bdev_discard_alignment(bdev) >> 9) % granularity;
Paolo Bonzinif6ff53d2012-08-02 09:48:49 +020062
Jens Axboe10d1f9e2010-07-15 10:49:31 -060063 /*
64 * Ensure that max_discard_sectors is of the proper
Paolo Bonzinic6e66632012-08-02 09:48:50 +020065 * granularity, so that requests stay aligned after a split.
Jens Axboe10d1f9e2010-07-15 10:49:31 -060066 */
67 max_discard_sectors = min(q->limits.max_discard_sectors, UINT_MAX >> 9);
Geert Uytterhoeven97597dc2013-11-04 14:00:06 +010068 max_discard_sectors -= max_discard_sectors % granularity;
Jens Axboe4c645002011-07-23 20:34:59 +020069 if (unlikely(!max_discard_sectors)) {
Mike Snitzer0f799602011-07-06 21:30:50 +020070 /* Avoid infinite loop below. Being cautious never hurts. */
71 return -EOPNOTSUPP;
Jens Axboe10d1f9e2010-07-15 10:49:31 -060072 }
73
Christoph Hellwigdd3932e2010-09-16 20:51:46 +020074 if (flags & BLKDEV_DISCARD_SECURE) {
Adrian Hunter8d57a982010-08-11 14:17:49 -070075 if (!blk_queue_secdiscard(q))
76 return -EOPNOTSUPP;
Christoph Hellwig8c555362010-08-18 05:29:22 -040077 type |= REQ_SECURE;
Adrian Hunter8d57a982010-08-11 14:17:49 -070078 }
79
Lukas Czerner5dba3082011-05-06 19:26:27 -060080 atomic_set(&bb.done, 1);
81 bb.flags = 1 << BIO_UPTODATE;
82 bb.wait = &wait;
83
Shaohua Li0cfbcaf2012-12-14 11:15:51 +080084 blk_start_plug(&plug);
Lukas Czerner5dba3082011-05-06 19:26:27 -060085 while (nr_sects) {
Paolo Bonzinic6e66632012-08-02 09:48:50 +020086 unsigned int req_sects;
Shaohua Li8dd2cb72012-12-14 11:15:36 +080087 sector_t end_sect, tmp;
Paolo Bonzinic6e66632012-08-02 09:48:50 +020088
Dmitry Monakhovf31e7e42010-04-28 17:55:08 +040089 bio = bio_alloc(gfp_mask, 1);
Christoph Hellwig66ac0282010-06-18 16:59:42 +020090 if (!bio) {
91 ret = -ENOMEM;
92 break;
93 }
94
Paolo Bonzinic6e66632012-08-02 09:48:50 +020095 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;
Shaohua Li8dd2cb72012-12-14 11:15:36 +0800102 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;
Paolo Bonzinic6e66632012-08-02 09:48:50 +0200108 req_sects = end_sect - sector;
109 }
110
Dmitry Monakhovf31e7e42010-04-28 17:55:08 +0400111 bio->bi_sector = sector;
Lukas Czerner5dba3082011-05-06 19:26:27 -0600112 bio->bi_end_io = bio_batch_end_io;
Dmitry Monakhovf31e7e42010-04-28 17:55:08 +0400113 bio->bi_bdev = bdev;
Lukas Czerner5dba3082011-05-06 19:26:27 -0600114 bio->bi_private = &bb;
Dmitry Monakhovf31e7e42010-04-28 17:55:08 +0400115
Paolo Bonzinic6e66632012-08-02 09:48:50 +0200116 bio->bi_size = req_sects << 9;
117 nr_sects -= req_sects;
118 sector = end_sect;
Dmitry Monakhovf31e7e42010-04-28 17:55:08 +0400119
Lukas Czerner5dba3082011-05-06 19:26:27 -0600120 atomic_inc(&bb.done);
Dmitry Monakhovf31e7e42010-04-28 17:55:08 +0400121 submit_bio(type, bio);
Lukas Czerner5dba3082011-05-06 19:26:27 -0600122 }
Shaohua Li0cfbcaf2012-12-14 11:15:51 +0800123 blk_finish_plug(&plug);
Dmitry Monakhovf31e7e42010-04-28 17:55:08 +0400124
Lukas Czerner5dba3082011-05-06 19:26:27 -0600125 /* Wait for bios in-flight */
126 if (!atomic_dec_and_test(&bb.done))
Vladimir Davydov55770222013-02-14 18:19:59 +0400127 wait_for_completion_io(&wait);
Dmitry Monakhovf31e7e42010-04-28 17:55:08 +0400128
Lukas Czerner8af19542011-05-06 19:30:01 -0600129 if (!test_bit(BIO_UPTODATE, &bb.flags))
Lukas Czerner5dba3082011-05-06 19:26:27 -0600130 ret = -EIO;
Christoph Hellwig66ac0282010-06-18 16:59:42 +0200131
Dmitry Monakhovf31e7e42010-04-28 17:55:08 +0400132 return ret;
Dmitry Monakhovf31e7e42010-04-28 17:55:08 +0400133}
134EXPORT_SYMBOL(blkdev_issue_discard);
Dmitry Monakhov3f14d792010-04-28 17:55:09 +0400135
Dmitry Monakhov3f14d792010-04-28 17:55:09 +0400136/**
Martin K. Petersen4363ac72012-09-18 12:19:27 -0400137 * blkdev_issue_write_same - queue a write same operation
138 * @bdev: target blockdev
139 * @sector: start sector
140 * @nr_sects: number of sectors to write
141 * @gfp_mask: memory allocation flags (for bio_alloc)
142 * @page: page containing data to write
143 *
144 * Description:
145 * Issue a write same request for the sectors in question.
146 */
147int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
148 sector_t nr_sects, gfp_t gfp_mask,
149 struct page *page)
150{
151 DECLARE_COMPLETION_ONSTACK(wait);
152 struct request_queue *q = bdev_get_queue(bdev);
153 unsigned int max_write_same_sectors;
154 struct bio_batch bb;
155 struct bio *bio;
156 int ret = 0;
157
158 if (!q)
159 return -ENXIO;
160
161 max_write_same_sectors = q->limits.max_write_same_sectors;
162
163 if (max_write_same_sectors == 0)
164 return -EOPNOTSUPP;
165
166 atomic_set(&bb.done, 1);
167 bb.flags = 1 << BIO_UPTODATE;
168 bb.wait = &wait;
169
170 while (nr_sects) {
171 bio = bio_alloc(gfp_mask, 1);
172 if (!bio) {
173 ret = -ENOMEM;
174 break;
175 }
176
177 bio->bi_sector = sector;
178 bio->bi_end_io = bio_batch_end_io;
179 bio->bi_bdev = bdev;
180 bio->bi_private = &bb;
181 bio->bi_vcnt = 1;
182 bio->bi_io_vec->bv_page = page;
183 bio->bi_io_vec->bv_offset = 0;
184 bio->bi_io_vec->bv_len = bdev_logical_block_size(bdev);
185
186 if (nr_sects > max_write_same_sectors) {
187 bio->bi_size = max_write_same_sectors << 9;
188 nr_sects -= max_write_same_sectors;
189 sector += max_write_same_sectors;
190 } else {
191 bio->bi_size = nr_sects << 9;
192 nr_sects = 0;
193 }
194
195 atomic_inc(&bb.done);
196 submit_bio(REQ_WRITE | REQ_WRITE_SAME, bio);
197 }
198
199 /* Wait for bios in-flight */
200 if (!atomic_dec_and_test(&bb.done))
Vladimir Davydov55770222013-02-14 18:19:59 +0400201 wait_for_completion_io(&wait);
Martin K. Petersen4363ac72012-09-18 12:19:27 -0400202
203 if (!test_bit(BIO_UPTODATE, &bb.flags))
204 ret = -ENOTSUPP;
205
206 return ret;
207}
208EXPORT_SYMBOL(blkdev_issue_write_same);
209
210/**
Ben Hutchings291d24f2011-03-01 13:45:24 -0500211 * blkdev_issue_zeroout - generate number of zero filed write bios
Dmitry Monakhov3f14d792010-04-28 17:55:09 +0400212 * @bdev: blockdev to issue
213 * @sector: start sector
214 * @nr_sects: number of sectors to write
215 * @gfp_mask: memory allocation flags (for bio_alloc)
Dmitry Monakhov3f14d792010-04-28 17:55:09 +0400216 *
217 * Description:
218 * Generate and issue number of bios with zerofiled pages.
Dmitry Monakhov3f14d792010-04-28 17:55:09 +0400219 */
220
Martin K. Petersen579e8f32012-09-18 12:19:28 -0400221int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
Christoph Hellwigdd3932e2010-09-16 20:51:46 +0200222 sector_t nr_sects, gfp_t gfp_mask)
Dmitry Monakhov3f14d792010-04-28 17:55:09 +0400223{
Dmitry Monakhov18edc8e2010-08-06 13:23:25 +0200224 int ret;
Dmitry Monakhov3f14d792010-04-28 17:55:09 +0400225 struct bio *bio;
226 struct bio_batch bb;
Lukas Czerner0aeea182011-03-11 10:23:53 +0100227 unsigned int sz;
Dmitry Monakhov3f14d792010-04-28 17:55:09 +0400228 DECLARE_COMPLETION_ONSTACK(wait);
229
Lukas Czerner0aeea182011-03-11 10:23:53 +0100230 atomic_set(&bb.done, 1);
Dmitry Monakhov3f14d792010-04-28 17:55:09 +0400231 bb.flags = 1 << BIO_UPTODATE;
232 bb.wait = &wait;
Dmitry Monakhov3f14d792010-04-28 17:55:09 +0400233
Dmitry Monakhov18edc8e2010-08-06 13:23:25 +0200234 ret = 0;
Dmitry Monakhov3f14d792010-04-28 17:55:09 +0400235 while (nr_sects != 0) {
236 bio = bio_alloc(gfp_mask,
237 min(nr_sects, (sector_t)BIO_MAX_PAGES));
Dmitry Monakhov18edc8e2010-08-06 13:23:25 +0200238 if (!bio) {
239 ret = -ENOMEM;
Dmitry Monakhov3f14d792010-04-28 17:55:09 +0400240 break;
Dmitry Monakhov18edc8e2010-08-06 13:23:25 +0200241 }
Dmitry Monakhov3f14d792010-04-28 17:55:09 +0400242
243 bio->bi_sector = sector;
244 bio->bi_bdev = bdev;
245 bio->bi_end_io = bio_batch_end_io;
Christoph Hellwigdd3932e2010-09-16 20:51:46 +0200246 bio->bi_private = &bb;
Dmitry Monakhov3f14d792010-04-28 17:55:09 +0400247
Jens Axboe0341aaf2010-04-29 09:28:21 +0200248 while (nr_sects != 0) {
249 sz = min((sector_t) PAGE_SIZE >> 9 , nr_sects);
Dmitry Monakhov3f14d792010-04-28 17:55:09 +0400250 ret = bio_add_page(bio, ZERO_PAGE(0), sz << 9, 0);
251 nr_sects -= ret >> 9;
252 sector += ret >> 9;
253 if (ret < (sz << 9))
254 break;
255 }
Dmitry Monakhov18edc8e2010-08-06 13:23:25 +0200256 ret = 0;
Lukas Czerner0aeea182011-03-11 10:23:53 +0100257 atomic_inc(&bb.done);
Dmitry Monakhov3f14d792010-04-28 17:55:09 +0400258 submit_bio(WRITE, bio);
259 }
Dmitry Monakhov3f14d792010-04-28 17:55:09 +0400260
Christoph Hellwigdd3932e2010-09-16 20:51:46 +0200261 /* Wait for bios in-flight */
Lukas Czerner0aeea182011-03-11 10:23:53 +0100262 if (!atomic_dec_and_test(&bb.done))
Vladimir Davydov55770222013-02-14 18:19:59 +0400263 wait_for_completion_io(&wait);
Dmitry Monakhov3f14d792010-04-28 17:55:09 +0400264
265 if (!test_bit(BIO_UPTODATE, &bb.flags))
266 /* One of bios in the batch was completed with error.*/
267 ret = -EIO;
268
Dmitry Monakhov3f14d792010-04-28 17:55:09 +0400269 return ret;
270}
Martin K. Petersen579e8f32012-09-18 12:19:28 -0400271
272/**
273 * blkdev_issue_zeroout - zero-fill a block range
274 * @bdev: blockdev to write
275 * @sector: start sector
276 * @nr_sects: number of sectors to write
277 * @gfp_mask: memory allocation flags (for bio_alloc)
278 *
279 * Description:
280 * Generate and issue number of bios with zerofiled pages.
281 */
282
283int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
284 sector_t nr_sects, gfp_t gfp_mask)
285{
286 if (bdev_write_same(bdev)) {
287 unsigned char bdn[BDEVNAME_SIZE];
288
289 if (!blkdev_issue_write_same(bdev, sector, nr_sects, gfp_mask,
290 ZERO_PAGE(0)))
291 return 0;
292
293 bdevname(bdev, bdn);
294 pr_err("%s: WRITE SAME failed. Manually zeroing.\n", bdn);
295 }
296
297 return __blkdev_issue_zeroout(bdev, sector, nr_sects, gfp_mask);
298}
Dmitry Monakhov3f14d792010-04-28 17:55:09 +0400299EXPORT_SYMBOL(blkdev_issue_zeroout);