block: Do not call sector_div() with a 64-bit divisor
[platform/adaptation/renesas_rcar/renesas_kernel.git] / block / blk-lib.c
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 struct bio_batch {
13         atomic_t                done;
14         unsigned long           flags;
15         struct completion       *wait;
16 };
17
18 static 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  */
40 int 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_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_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         blk_finish_plug(&plug);
124
125         /* Wait for bios in-flight */
126         if (!atomic_dec_and_test(&bb.done))
127                 wait_for_completion_io(&wait);
128
129         if (!test_bit(BIO_UPTODATE, &bb.flags))
130                 ret = -EIO;
131
132         return ret;
133 }
134 EXPORT_SYMBOL(blkdev_issue_discard);
135
136 /**
137  * 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  */
147 int 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))
201                 wait_for_completion_io(&wait);
202
203         if (!test_bit(BIO_UPTODATE, &bb.flags))
204                 ret = -ENOTSUPP;
205
206         return ret;
207 }
208 EXPORT_SYMBOL(blkdev_issue_write_same);
209
210 /**
211  * blkdev_issue_zeroout - generate number of zero filed write bios
212  * @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)
216  *
217  * Description:
218  *  Generate and issue number of bios with zerofiled pages.
219  */
220
221 int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
222                         sector_t nr_sects, gfp_t gfp_mask)
223 {
224         int ret;
225         struct bio *bio;
226         struct bio_batch bb;
227         unsigned int sz;
228         DECLARE_COMPLETION_ONSTACK(wait);
229
230         atomic_set(&bb.done, 1);
231         bb.flags = 1 << BIO_UPTODATE;
232         bb.wait = &wait;
233
234         ret = 0;
235         while (nr_sects != 0) {
236                 bio = bio_alloc(gfp_mask,
237                                 min(nr_sects, (sector_t)BIO_MAX_PAGES));
238                 if (!bio) {
239                         ret = -ENOMEM;
240                         break;
241                 }
242
243                 bio->bi_sector = sector;
244                 bio->bi_bdev   = bdev;
245                 bio->bi_end_io = bio_batch_end_io;
246                 bio->bi_private = &bb;
247
248                 while (nr_sects != 0) {
249                         sz = min((sector_t) PAGE_SIZE >> 9 , nr_sects);
250                         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                 }
256                 ret = 0;
257                 atomic_inc(&bb.done);
258                 submit_bio(WRITE, bio);
259         }
260
261         /* Wait for bios in-flight */
262         if (!atomic_dec_and_test(&bb.done))
263                 wait_for_completion_io(&wait);
264
265         if (!test_bit(BIO_UPTODATE, &bb.flags))
266                 /* One of bios in the batch was completed with error.*/
267                 ret = -EIO;
268
269         return ret;
270 }
271
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
283 int 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 }
299 EXPORT_SYMBOL(blkdev_issue_zeroout);