2 * Functions related to generic helpers functions
4 #include <linux/kernel.h>
5 #include <linux/module.h>
7 #include <linux/blkdev.h>
8 #include <linux/scatterlist.h>
15 struct completion *wait;
18 static void bio_batch_end_io(struct bio *bio, int err)
20 struct bio_batch *bb = bio->bi_private;
22 if (err && (err != -EOPNOTSUPP))
23 clear_bit(BIO_UPTODATE, &bb->flags);
24 if (atomic_dec_and_test(&bb->done))
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
38 * Issue a discard request for the sectors in question.
40 int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
41 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags)
43 DECLARE_COMPLETION_ONSTACK(wait);
44 struct request_queue *q = bdev_get_queue(bdev);
45 int type = REQ_WRITE | REQ_DISCARD;
46 sector_t max_discard_sectors;
47 sector_t granularity, alignment;
56 if (!blk_queue_discard(q))
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;
62 alignment = sector_div(alignment, granularity);
65 * Ensure that max_discard_sectors is of the proper
66 * granularity, so that requests stay aligned after a split.
68 max_discard_sectors = min(q->limits.max_discard_sectors, UINT_MAX >> 9);
69 sector_div(max_discard_sectors, granularity);
70 max_discard_sectors *= granularity;
71 if (unlikely(!max_discard_sectors)) {
72 /* Avoid infinite loop below. Being cautious never hurts. */
76 if (flags & BLKDEV_DISCARD_SECURE) {
77 if (!blk_queue_secdiscard(q))
82 atomic_set(&bb.done, 1);
83 bb.flags = 1 << BIO_UPTODATE;
86 blk_start_plug(&plug);
88 unsigned int req_sects;
89 sector_t end_sect, tmp;
91 bio = bio_alloc(gfp_mask, 1);
97 req_sects = min_t(sector_t, nr_sects, max_discard_sectors);
100 * If splitting a request, and the next starting sector would be
101 * misaligned, stop the discard at the previous aligned sector.
103 end_sect = sector + req_sects;
105 if (req_sects < nr_sects &&
106 sector_div(tmp, granularity) != alignment) {
107 end_sect = end_sect - alignment;
108 sector_div(end_sect, granularity);
109 end_sect = end_sect * granularity + alignment;
110 req_sects = end_sect - sector;
113 bio->bi_sector = sector;
114 bio->bi_end_io = bio_batch_end_io;
116 bio->bi_private = &bb;
118 bio->bi_size = req_sects << 9;
119 nr_sects -= req_sects;
122 atomic_inc(&bb.done);
123 submit_bio(type, bio);
126 * We can loop for a long time in here, if someone does
127 * full device discards (like mkfs). Be nice and allow
128 * us to schedule out to avoid softlocking if preempt
133 blk_finish_plug(&plug);
135 /* Wait for bios in-flight */
136 if (!atomic_dec_and_test(&bb.done))
137 wait_for_completion_io(&wait);
139 if (!test_bit(BIO_UPTODATE, &bb.flags))
144 EXPORT_SYMBOL(blkdev_issue_discard);
147 * blkdev_issue_write_same - queue a write same operation
148 * @bdev: target blockdev
149 * @sector: start sector
150 * @nr_sects: number of sectors to write
151 * @gfp_mask: memory allocation flags (for bio_alloc)
152 * @page: page containing data to write
155 * Issue a write same request for the sectors in question.
157 int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
158 sector_t nr_sects, gfp_t gfp_mask,
161 DECLARE_COMPLETION_ONSTACK(wait);
162 struct request_queue *q = bdev_get_queue(bdev);
163 unsigned int max_write_same_sectors;
171 max_write_same_sectors = q->limits.max_write_same_sectors;
173 if (max_write_same_sectors == 0)
176 atomic_set(&bb.done, 1);
177 bb.flags = 1 << BIO_UPTODATE;
181 bio = bio_alloc(gfp_mask, 1);
187 bio->bi_sector = sector;
188 bio->bi_end_io = bio_batch_end_io;
190 bio->bi_private = &bb;
192 bio->bi_io_vec->bv_page = page;
193 bio->bi_io_vec->bv_offset = 0;
194 bio->bi_io_vec->bv_len = bdev_logical_block_size(bdev);
196 if (nr_sects > max_write_same_sectors) {
197 bio->bi_size = max_write_same_sectors << 9;
198 nr_sects -= max_write_same_sectors;
199 sector += max_write_same_sectors;
201 bio->bi_size = nr_sects << 9;
205 atomic_inc(&bb.done);
206 submit_bio(REQ_WRITE | REQ_WRITE_SAME, bio);
209 /* Wait for bios in-flight */
210 if (!atomic_dec_and_test(&bb.done))
211 wait_for_completion_io(&wait);
213 if (!test_bit(BIO_UPTODATE, &bb.flags))
218 EXPORT_SYMBOL(blkdev_issue_write_same);
221 * blkdev_issue_zeroout - generate number of zero filed write bios
222 * @bdev: blockdev to issue
223 * @sector: start sector
224 * @nr_sects: number of sectors to write
225 * @gfp_mask: memory allocation flags (for bio_alloc)
228 * Generate and issue number of bios with zerofiled pages.
231 int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
232 sector_t nr_sects, gfp_t gfp_mask)
238 DECLARE_COMPLETION_ONSTACK(wait);
240 atomic_set(&bb.done, 1);
241 bb.flags = 1 << BIO_UPTODATE;
245 while (nr_sects != 0) {
246 bio = bio_alloc(gfp_mask,
247 min(nr_sects, (sector_t)BIO_MAX_PAGES));
253 bio->bi_sector = sector;
255 bio->bi_end_io = bio_batch_end_io;
256 bio->bi_private = &bb;
258 while (nr_sects != 0) {
259 sz = min((sector_t) PAGE_SIZE >> 9 , nr_sects);
260 ret = bio_add_page(bio, ZERO_PAGE(0), sz << 9, 0);
261 nr_sects -= ret >> 9;
267 atomic_inc(&bb.done);
268 submit_bio(WRITE, bio);
271 /* Wait for bios in-flight */
272 if (!atomic_dec_and_test(&bb.done))
273 wait_for_completion_io(&wait);
275 if (!test_bit(BIO_UPTODATE, &bb.flags))
276 /* One of bios in the batch was completed with error.*/
283 * blkdev_issue_zeroout - zero-fill a block range
284 * @bdev: blockdev to write
285 * @sector: start sector
286 * @nr_sects: number of sectors to write
287 * @gfp_mask: memory allocation flags (for bio_alloc)
290 * Generate and issue number of bios with zerofiled pages.
293 int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
294 sector_t nr_sects, gfp_t gfp_mask)
296 if (bdev_write_same(bdev)) {
297 unsigned char bdn[BDEVNAME_SIZE];
299 if (!blkdev_issue_write_same(bdev, sector, nr_sects, gfp_mask,
304 pr_err("%s: WRITE SAME failed. Manually zeroing.\n", bdn);
307 return __blkdev_issue_zeroout(bdev, sector, nr_sects, gfp_mask);
309 EXPORT_SYMBOL(blkdev_issue_zeroout);