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 unsigned int max_discard_sectors;
47 unsigned int granularity;
55 if (!blk_queue_discard(q))
58 /* Zero-sector (unknown) and one-sector granularities are the same. */
59 granularity = max(q->limits.discard_granularity >> 9, 1U);
62 * Ensure that max_discard_sectors is of the proper
65 max_discard_sectors = min(q->limits.max_discard_sectors, UINT_MAX >> 9);
66 max_discard_sectors = round_down(max_discard_sectors, granularity);
67 if (unlikely(!max_discard_sectors)) {
68 /* Avoid infinite loop below. Being cautious never hurts. */
72 if (flags & BLKDEV_DISCARD_SECURE) {
73 if (!blk_queue_secdiscard(q))
78 atomic_set(&bb.done, 1);
79 bb.flags = 1 << BIO_UPTODATE;
83 bio = bio_alloc(gfp_mask, 1);
89 bio->bi_sector = sector;
90 bio->bi_end_io = bio_batch_end_io;
92 bio->bi_private = &bb;
94 if (nr_sects > max_discard_sectors) {
95 bio->bi_size = max_discard_sectors << 9;
96 nr_sects -= max_discard_sectors;
97 sector += max_discard_sectors;
99 bio->bi_size = nr_sects << 9;
103 atomic_inc(&bb.done);
104 submit_bio(type, bio);
107 /* Wait for bios in-flight */
108 if (!atomic_dec_and_test(&bb.done))
109 wait_for_completion(&wait);
111 if (!test_bit(BIO_UPTODATE, &bb.flags))
116 EXPORT_SYMBOL(blkdev_issue_discard);
119 * blkdev_issue_zeroout - generate number of zero filed write bios
120 * @bdev: blockdev to issue
121 * @sector: start sector
122 * @nr_sects: number of sectors to write
123 * @gfp_mask: memory allocation flags (for bio_alloc)
126 * Generate and issue number of bios with zerofiled pages.
129 int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
130 sector_t nr_sects, gfp_t gfp_mask)
136 DECLARE_COMPLETION_ONSTACK(wait);
138 atomic_set(&bb.done, 1);
139 bb.flags = 1 << BIO_UPTODATE;
143 while (nr_sects != 0) {
144 bio = bio_alloc(gfp_mask,
145 min(nr_sects, (sector_t)BIO_MAX_PAGES));
151 bio->bi_sector = sector;
153 bio->bi_end_io = bio_batch_end_io;
154 bio->bi_private = &bb;
156 while (nr_sects != 0) {
157 sz = min((sector_t) PAGE_SIZE >> 9 , nr_sects);
158 ret = bio_add_page(bio, ZERO_PAGE(0), sz << 9, 0);
159 nr_sects -= ret >> 9;
165 atomic_inc(&bb.done);
166 submit_bio(WRITE, bio);
169 /* Wait for bios in-flight */
170 if (!atomic_dec_and_test(&bb.done))
171 wait_for_completion(&wait);
173 if (!test_bit(BIO_UPTODATE, &bb.flags))
174 /* One of bios in the batch was completed with error.*/
179 EXPORT_SYMBOL(blkdev_issue_zeroout);