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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
Mike Christie4e49ea42016-06-05 14:31:41 -050012static struct bio *next_bio(struct bio *bio, unsigned int nr_pages,
Christoph Hellwig9082e872016-04-16 14:55:27 -040013 gfp_t gfp)
Dmitry Monakhovf31e7e42010-04-28 17:55:08 +040014{
Christoph Hellwig9082e872016-04-16 14:55:27 -040015 struct bio *new = bio_alloc(gfp, nr_pages);
Lukas Czerner5dba3082011-05-06 19:26:27 -060016
Christoph Hellwig9082e872016-04-16 14:55:27 -040017 if (bio) {
18 bio_chain(bio, new);
Mike Christie4e49ea42016-06-05 14:31:41 -050019 submit_bio(bio);
Christoph Hellwig9082e872016-04-16 14:55:27 -040020 }
21
22 return new;
Dmitry Monakhovf31e7e42010-04-28 17:55:08 +040023}
24
Christoph Hellwig38f25252016-04-16 14:55:28 -040025int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
Christoph Hellwig288dab82016-06-09 16:00:36 +020026 sector_t nr_sects, gfp_t gfp_mask, int flags,
Mike Christie469e3212016-06-05 14:31:49 -050027 struct bio **biop)
Dmitry Monakhovf31e7e42010-04-28 17:55:08 +040028{
Dmitry Monakhovf31e7e42010-04-28 17:55:08 +040029 struct request_queue *q = bdev_get_queue(bdev);
Christoph Hellwig38f25252016-04-16 14:55:28 -040030 struct bio *bio = *biop;
Ming Lina22c4d72015-10-22 09:59:42 -070031 unsigned int granularity;
Christoph Hellwig288dab82016-06-09 16:00:36 +020032 enum req_op op;
Ming Lina22c4d72015-10-22 09:59:42 -070033 int alignment;
Dmitry Monakhovf31e7e42010-04-28 17:55:08 +040034
35 if (!q)
36 return -ENXIO;
Christoph Hellwig288dab82016-06-09 16:00:36 +020037
38 if (flags & BLKDEV_DISCARD_SECURE) {
Christoph Hellwige950fdf2016-07-19 11:23:33 +020039 if (flags & BLKDEV_DISCARD_ZERO)
40 return -EOPNOTSUPP;
Christoph Hellwig288dab82016-06-09 16:00:36 +020041 if (!blk_queue_secure_erase(q))
42 return -EOPNOTSUPP;
43 op = REQ_OP_SECURE_ERASE;
44 } else {
45 if (!blk_queue_discard(q))
46 return -EOPNOTSUPP;
Christoph Hellwige950fdf2016-07-19 11:23:33 +020047 if ((flags & BLKDEV_DISCARD_ZERO) &&
48 !q->limits.discard_zeroes_data)
49 return -EOPNOTSUPP;
Christoph Hellwig288dab82016-06-09 16:00:36 +020050 op = REQ_OP_DISCARD;
51 }
Dmitry Monakhovf31e7e42010-04-28 17:55:08 +040052
Ming Lina22c4d72015-10-22 09:59:42 -070053 /* Zero-sector (unknown) and one-sector granularities are the same. */
54 granularity = max(q->limits.discard_granularity >> 9, 1U);
55 alignment = (bdev_discard_alignment(bdev) >> 9) % granularity;
56
Lukas Czerner5dba3082011-05-06 19:26:27 -060057 while (nr_sects) {
Paolo Bonzinic6e66632012-08-02 09:48:50 +020058 unsigned int req_sects;
Ming Lina22c4d72015-10-22 09:59:42 -070059 sector_t end_sect, tmp;
Paolo Bonzinic6e66632012-08-02 09:48:50 +020060
Ming Lina22c4d72015-10-22 09:59:42 -070061 /* Make sure bi_size doesn't overflow */
62 req_sects = min_t(sector_t, nr_sects, UINT_MAX >> 9);
63
Christoph Hellwig9082e872016-04-16 14:55:27 -040064 /**
Ming Lina22c4d72015-10-22 09:59:42 -070065 * If splitting a request, and the next starting sector would be
66 * misaligned, stop the discard at the previous aligned sector.
67 */
Paolo Bonzinic6e66632012-08-02 09:48:50 +020068 end_sect = sector + req_sects;
Ming Lina22c4d72015-10-22 09:59:42 -070069 tmp = end_sect;
70 if (req_sects < nr_sects &&
71 sector_div(tmp, granularity) != alignment) {
72 end_sect = end_sect - alignment;
73 sector_div(end_sect, granularity);
74 end_sect = end_sect * granularity + alignment;
75 req_sects = end_sect - sector;
76 }
Paolo Bonzinic6e66632012-08-02 09:48:50 +020077
Mike Christie4e49ea42016-06-05 14:31:41 -050078 bio = next_bio(bio, 1, gfp_mask);
Kent Overstreet4f024f32013-10-11 15:44:27 -070079 bio->bi_iter.bi_sector = sector;
Dmitry Monakhovf31e7e42010-04-28 17:55:08 +040080 bio->bi_bdev = bdev;
Christoph Hellwig288dab82016-06-09 16:00:36 +020081 bio_set_op_attrs(bio, op, 0);
Dmitry Monakhovf31e7e42010-04-28 17:55:08 +040082
Kent Overstreet4f024f32013-10-11 15:44:27 -070083 bio->bi_iter.bi_size = req_sects << 9;
Paolo Bonzinic6e66632012-08-02 09:48:50 +020084 nr_sects -= req_sects;
85 sector = end_sect;
Dmitry Monakhovf31e7e42010-04-28 17:55:08 +040086
Jens Axboec8123f82014-02-12 09:34:01 -070087 /*
88 * We can loop for a long time in here, if someone does
89 * full device discards (like mkfs). Be nice and allow
90 * us to schedule out to avoid softlocking if preempt
91 * is disabled.
92 */
93 cond_resched();
Lukas Czerner5dba3082011-05-06 19:26:27 -060094 }
Christoph Hellwig38f25252016-04-16 14:55:28 -040095
96 *biop = bio;
97 return 0;
98}
99EXPORT_SYMBOL(__blkdev_issue_discard);
100
101/**
102 * blkdev_issue_discard - queue a discard
103 * @bdev: blockdev to issue discard for
104 * @sector: start sector
105 * @nr_sects: number of sectors to discard
106 * @gfp_mask: memory allocation flags (for bio_alloc)
107 * @flags: BLKDEV_IFL_* flags to control behaviour
108 *
109 * Description:
110 * Issue a discard request for the sectors in question.
111 */
112int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
113 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags)
114{
Christoph Hellwig38f25252016-04-16 14:55:28 -0400115 struct bio *bio = NULL;
116 struct blk_plug plug;
117 int ret;
118
Christoph Hellwig38f25252016-04-16 14:55:28 -0400119 blk_start_plug(&plug);
Christoph Hellwig288dab82016-06-09 16:00:36 +0200120 ret = __blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask, flags,
Christoph Hellwig38f25252016-04-16 14:55:28 -0400121 &bio);
Mike Snitzerbbd848e0f2016-05-05 11:54:21 -0400122 if (!ret && bio) {
Mike Christie4e49ea42016-06-05 14:31:41 -0500123 ret = submit_bio_wait(bio);
Christoph Hellwige950fdf2016-07-19 11:23:33 +0200124 if (ret == -EOPNOTSUPP && !(flags & BLKDEV_DISCARD_ZERO))
Mike Snitzerbbd848e0f2016-05-05 11:54:21 -0400125 ret = 0;
Shaun Tancheff05bd92d2016-06-07 11:32:13 -0500126 bio_put(bio);
Mike Snitzerbbd848e0f2016-05-05 11:54:21 -0400127 }
Shaohua Li0cfbcaf2012-12-14 11:15:51 +0800128 blk_finish_plug(&plug);
Dmitry Monakhovf31e7e42010-04-28 17:55:08 +0400129
Mike Snitzerbbd848e0f2016-05-05 11:54:21 -0400130 return ret;
Dmitry Monakhovf31e7e42010-04-28 17:55:08 +0400131}
132EXPORT_SYMBOL(blkdev_issue_discard);
Dmitry Monakhov3f14d792010-04-28 17:55:09 +0400133
Dmitry Monakhov3f14d792010-04-28 17:55:09 +0400134/**
Martin K. Petersen4363ac72012-09-18 12:19:27 -0400135 * blkdev_issue_write_same - queue a write same operation
136 * @bdev: target blockdev
137 * @sector: start sector
138 * @nr_sects: number of sectors to write
139 * @gfp_mask: memory allocation flags (for bio_alloc)
140 * @page: page containing data to write
141 *
142 * Description:
143 * Issue a write same request for the sectors in question.
144 */
145int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
146 sector_t nr_sects, gfp_t gfp_mask,
147 struct page *page)
148{
Martin K. Petersen4363ac72012-09-18 12:19:27 -0400149 struct request_queue *q = bdev_get_queue(bdev);
150 unsigned int max_write_same_sectors;
Christoph Hellwig9082e872016-04-16 14:55:27 -0400151 struct bio *bio = NULL;
Martin K. Petersen4363ac72012-09-18 12:19:27 -0400152 int ret = 0;
153
154 if (!q)
155 return -ENXIO;
156
Ming Linb49a0872015-05-22 00:46:56 -0700157 /* Ensure that max_write_same_sectors doesn't overflow bi_size */
158 max_write_same_sectors = UINT_MAX >> 9;
Martin K. Petersen4363ac72012-09-18 12:19:27 -0400159
Martin K. Petersen4363ac72012-09-18 12:19:27 -0400160 while (nr_sects) {
Mike Christie4e49ea42016-06-05 14:31:41 -0500161 bio = next_bio(bio, 1, gfp_mask);
Kent Overstreet4f024f32013-10-11 15:44:27 -0700162 bio->bi_iter.bi_sector = sector;
Martin K. Petersen4363ac72012-09-18 12:19:27 -0400163 bio->bi_bdev = bdev;
Martin K. Petersen4363ac72012-09-18 12:19:27 -0400164 bio->bi_vcnt = 1;
165 bio->bi_io_vec->bv_page = page;
166 bio->bi_io_vec->bv_offset = 0;
167 bio->bi_io_vec->bv_len = bdev_logical_block_size(bdev);
Mike Christie95fe6c12016-06-05 14:31:48 -0500168 bio_set_op_attrs(bio, REQ_OP_WRITE_SAME, 0);
Martin K. Petersen4363ac72012-09-18 12:19:27 -0400169
170 if (nr_sects > max_write_same_sectors) {
Kent Overstreet4f024f32013-10-11 15:44:27 -0700171 bio->bi_iter.bi_size = max_write_same_sectors << 9;
Martin K. Petersen4363ac72012-09-18 12:19:27 -0400172 nr_sects -= max_write_same_sectors;
173 sector += max_write_same_sectors;
174 } else {
Kent Overstreet4f024f32013-10-11 15:44:27 -0700175 bio->bi_iter.bi_size = nr_sects << 9;
Martin K. Petersen4363ac72012-09-18 12:19:27 -0400176 nr_sects = 0;
177 }
Martin K. Petersen4363ac72012-09-18 12:19:27 -0400178 }
179
Shaun Tancheff05bd92d2016-06-07 11:32:13 -0500180 if (bio) {
Mike Christie4e49ea42016-06-05 14:31:41 -0500181 ret = submit_bio_wait(bio);
Shaun Tancheff05bd92d2016-06-07 11:32:13 -0500182 bio_put(bio);
183 }
Christoph Hellwig3f40bf22016-07-19 11:23:34 +0200184 return ret;
Martin K. Petersen4363ac72012-09-18 12:19:27 -0400185}
186EXPORT_SYMBOL(blkdev_issue_write_same);
187
188/**
Ben Hutchings291d24f2011-03-01 13:45:24 -0500189 * blkdev_issue_zeroout - generate number of zero filed write bios
Dmitry Monakhov3f14d792010-04-28 17:55:09 +0400190 * @bdev: blockdev to issue
191 * @sector: start sector
192 * @nr_sects: number of sectors to write
193 * @gfp_mask: memory allocation flags (for bio_alloc)
Dmitry Monakhov3f14d792010-04-28 17:55:09 +0400194 *
195 * Description:
196 * Generate and issue number of bios with zerofiled pages.
Dmitry Monakhov3f14d792010-04-28 17:55:09 +0400197 */
198
Fabian Frederick35086782014-05-26 22:19:14 +0200199static int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
200 sector_t nr_sects, gfp_t gfp_mask)
Dmitry Monakhov3f14d792010-04-28 17:55:09 +0400201{
Dmitry Monakhov18edc8e2010-08-06 13:23:25 +0200202 int ret;
Christoph Hellwig9082e872016-04-16 14:55:27 -0400203 struct bio *bio = NULL;
Lukas Czerner0aeea182011-03-11 10:23:53 +0100204 unsigned int sz;
Dmitry Monakhov3f14d792010-04-28 17:55:09 +0400205
Dmitry Monakhov3f14d792010-04-28 17:55:09 +0400206 while (nr_sects != 0) {
Mike Christie4e49ea42016-06-05 14:31:41 -0500207 bio = next_bio(bio, min(nr_sects, (sector_t)BIO_MAX_PAGES),
Christoph Hellwig9082e872016-04-16 14:55:27 -0400208 gfp_mask);
Kent Overstreet4f024f32013-10-11 15:44:27 -0700209 bio->bi_iter.bi_sector = sector;
Dmitry Monakhov3f14d792010-04-28 17:55:09 +0400210 bio->bi_bdev = bdev;
Mike Christie95fe6c12016-06-05 14:31:48 -0500211 bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
Dmitry Monakhov3f14d792010-04-28 17:55:09 +0400212
Jens Axboe0341aaf2010-04-29 09:28:21 +0200213 while (nr_sects != 0) {
214 sz = min((sector_t) PAGE_SIZE >> 9 , nr_sects);
Dmitry Monakhov3f14d792010-04-28 17:55:09 +0400215 ret = bio_add_page(bio, ZERO_PAGE(0), sz << 9, 0);
216 nr_sects -= ret >> 9;
217 sector += ret >> 9;
218 if (ret < (sz << 9))
219 break;
220 }
Dmitry Monakhov3f14d792010-04-28 17:55:09 +0400221 }
Dmitry Monakhov3f14d792010-04-28 17:55:09 +0400222
Shaun Tancheff05bd92d2016-06-07 11:32:13 -0500223 if (bio) {
Linus Torvaldsd05d7f42016-07-26 15:03:07 -0700224 ret = submit_bio_wait(bio);
Shaun Tancheff05bd92d2016-06-07 11:32:13 -0500225 bio_put(bio);
226 return ret;
227 }
Christoph Hellwig9082e872016-04-16 14:55:27 -0400228 return 0;
Dmitry Monakhov3f14d792010-04-28 17:55:09 +0400229}
Martin K. Petersen579e8f32012-09-18 12:19:28 -0400230
231/**
232 * blkdev_issue_zeroout - zero-fill a block range
233 * @bdev: blockdev to write
234 * @sector: start sector
235 * @nr_sects: number of sectors to write
236 * @gfp_mask: memory allocation flags (for bio_alloc)
Martin K. Petersend93ba7a2015-01-20 20:06:30 -0500237 * @discard: whether to discard the block range
Martin K. Petersen579e8f32012-09-18 12:19:28 -0400238 *
239 * Description:
Martin K. Petersend93ba7a2015-01-20 20:06:30 -0500240 * Zero-fill a block range. If the discard flag is set and the block
241 * device guarantees that subsequent READ operations to the block range
242 * in question will return zeroes, the blocks will be discarded. Should
243 * the discard request fail, if the discard flag is not set, or if
244 * discard_zeroes_data is not supported, this function will resort to
245 * zeroing the blocks manually, thus provisioning (allocating,
246 * anchoring) them. If the block device supports the WRITE SAME command
247 * blkdev_issue_zeroout() will use it to optimize the process of
248 * clearing the block range. Otherwise the zeroing will be performed
249 * using regular WRITE calls.
Martin K. Petersen579e8f32012-09-18 12:19:28 -0400250 */
251
252int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
Martin K. Petersend93ba7a2015-01-20 20:06:30 -0500253 sector_t nr_sects, gfp_t gfp_mask, bool discard)
Martin K. Petersen579e8f32012-09-18 12:19:28 -0400254{
Christoph Hellwige950fdf2016-07-19 11:23:33 +0200255 if (discard) {
256 if (!blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask,
257 BLKDEV_DISCARD_ZERO))
258 return 0;
259 }
Martin K. Petersend93ba7a2015-01-20 20:06:30 -0500260
Martin K. Petersen9f9ee1f2015-02-05 10:14:54 -0700261 if (bdev_write_same(bdev) &&
262 blkdev_issue_write_same(bdev, sector, nr_sects, gfp_mask,
263 ZERO_PAGE(0)) == 0)
264 return 0;
Martin K. Petersen579e8f32012-09-18 12:19:28 -0400265
266 return __blkdev_issue_zeroout(bdev, sector, nr_sects, gfp_mask);
267}
Dmitry Monakhov3f14d792010-04-28 17:55:09 +0400268EXPORT_SYMBOL(blkdev_issue_zeroout);