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;
23 if (err == -EOPNOTSUPP)
24 set_bit(BIO_EOPNOTSUPP, &bb->flags);
25 clear_bit(BIO_UPTODATE, &bb->flags);
27 if (atomic_dec_and_test(&bb->done))
33 * blkdev_issue_discard - queue a discard
34 * @bdev: blockdev to issue discard for
35 * @sector: start sector
36 * @nr_sects: number of sectors to discard
37 * @gfp_mask: memory allocation flags (for bio_alloc)
38 * @flags: BLKDEV_IFL_* flags to control behaviour
41 * Issue a discard request for the sectors in question.
43 int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
44 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags)
46 DECLARE_COMPLETION_ONSTACK(wait);
47 struct request_queue *q = bdev_get_queue(bdev);
48 int type = REQ_WRITE | REQ_DISCARD;
49 unsigned int max_discard_sectors;
57 if (!blk_queue_discard(q))
61 * Ensure that max_discard_sectors is of the proper
64 max_discard_sectors = min(q->limits.max_discard_sectors, UINT_MAX >> 9);
65 if (q->limits.discard_granularity) {
66 unsigned int disc_sects = q->limits.discard_granularity >> 9;
68 max_discard_sectors &= ~(disc_sects - 1);
71 if (flags & BLKDEV_DISCARD_SECURE) {
72 if (!blk_queue_secdiscard(q))
77 atomic_set(&bb.done, 1);
78 bb.flags = 1 << BIO_UPTODATE;
82 bio = bio_alloc(gfp_mask, 1);
88 bio->bi_sector = sector;
89 bio->bi_end_io = bio_batch_end_io;
91 bio->bi_private = &bb;
93 if (nr_sects > max_discard_sectors) {
94 bio->bi_size = max_discard_sectors << 9;
95 nr_sects -= max_discard_sectors;
96 sector += max_discard_sectors;
98 bio->bi_size = nr_sects << 9;
102 atomic_inc(&bb.done);
103 submit_bio(type, bio);
106 /* Wait for bios in-flight */
107 if (!atomic_dec_and_test(&bb.done))
108 wait_for_completion(&wait);
110 if (test_bit(BIO_EOPNOTSUPP, &bb.flags))
112 else if (!test_bit(BIO_UPTODATE, &bb.flags))
117 EXPORT_SYMBOL(blkdev_issue_discard);
120 * blkdev_issue_zeroout - generate number of zero filed write bios
121 * @bdev: blockdev to issue
122 * @sector: start sector
123 * @nr_sects: number of sectors to write
124 * @gfp_mask: memory allocation flags (for bio_alloc)
127 * Generate and issue number of bios with zerofiled pages.
130 int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
131 sector_t nr_sects, gfp_t gfp_mask)
137 DECLARE_COMPLETION_ONSTACK(wait);
139 atomic_set(&bb.done, 1);
140 bb.flags = 1 << BIO_UPTODATE;
145 while (nr_sects != 0) {
146 bio = bio_alloc(gfp_mask,
147 min(nr_sects, (sector_t)BIO_MAX_PAGES));
153 bio->bi_sector = sector;
155 bio->bi_end_io = bio_batch_end_io;
156 bio->bi_private = &bb;
158 while (nr_sects != 0) {
159 sz = min((sector_t) PAGE_SIZE >> 9 , nr_sects);
161 /* bio has maximum size possible */
163 ret = bio_add_page(bio, ZERO_PAGE(0), sz << 9, 0);
164 nr_sects -= ret >> 9;
170 atomic_inc(&bb.done);
171 submit_bio(WRITE, bio);
174 /* Wait for bios in-flight */
175 if (!atomic_dec_and_test(&bb.done))
176 wait_for_completion(&wait);
178 if (!test_bit(BIO_UPTODATE, &bb.flags))
179 /* One of bios in the batch was completed with error.*/
185 if (test_bit(BIO_EOPNOTSUPP, &bb.flags)) {
194 EXPORT_SYMBOL(blkdev_issue_zeroout);