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>
12 static void blkdev_discard_end_io(struct bio *bio, int err)
15 if (err == -EOPNOTSUPP)
16 set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
17 clear_bit(BIO_UPTODATE, &bio->bi_flags);
21 complete(bio->bi_private);
27 * blkdev_issue_discard - queue a discard
28 * @bdev: blockdev to issue discard for
29 * @sector: start sector
30 * @nr_sects: number of sectors to discard
31 * @gfp_mask: memory allocation flags (for bio_alloc)
32 * @flags: BLKDEV_IFL_* flags to control behaviour
35 * Issue a discard request for the sectors in question.
37 int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
38 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags)
40 DECLARE_COMPLETION_ONSTACK(wait);
41 struct request_queue *q = bdev_get_queue(bdev);
42 int type = flags & BLKDEV_IFL_BARRIER ?
43 DISCARD_BARRIER : DISCARD_NOBARRIER;
44 unsigned int max_discard_sectors;
51 if (!blk_queue_discard(q))
55 * Ensure that max_discard_sectors is of the proper
58 max_discard_sectors = min(q->limits.max_discard_sectors, UINT_MAX >> 9);
59 if (q->limits.discard_granularity) {
60 unsigned int disc_sects = q->limits.discard_granularity >> 9;
62 max_discard_sectors &= ~(disc_sects - 1);
65 while (nr_sects && !ret) {
66 bio = bio_alloc(gfp_mask, 1);
72 bio->bi_sector = sector;
73 bio->bi_end_io = blkdev_discard_end_io;
75 if (flags & BLKDEV_IFL_WAIT)
76 bio->bi_private = &wait;
78 if (nr_sects > max_discard_sectors) {
79 bio->bi_size = max_discard_sectors << 9;
80 nr_sects -= max_discard_sectors;
81 sector += max_discard_sectors;
83 bio->bi_size = nr_sects << 9;
88 submit_bio(type, bio);
90 if (flags & BLKDEV_IFL_WAIT)
91 wait_for_completion(&wait);
93 if (bio_flagged(bio, BIO_EOPNOTSUPP))
95 else if (!bio_flagged(bio, BIO_UPTODATE))
102 EXPORT_SYMBOL(blkdev_issue_discard);
108 struct completion *wait;
109 bio_end_io_t *end_io;
112 static void bio_batch_end_io(struct bio *bio, int err)
114 struct bio_batch *bb = bio->bi_private;
117 if (err == -EOPNOTSUPP)
118 set_bit(BIO_EOPNOTSUPP, &bb->flags);
120 clear_bit(BIO_UPTODATE, &bb->flags);
124 bb->end_io(bio, err);
125 atomic_inc(&bb->done);
132 * blkdev_issue_zeroout generate number of zero filed write bios
133 * @bdev: blockdev to issue
134 * @sector: start sector
135 * @nr_sects: number of sectors to write
136 * @gfp_mask: memory allocation flags (for bio_alloc)
137 * @flags: BLKDEV_IFL_* flags to control behaviour
140 * Generate and issue number of bios with zerofiled pages.
141 * Send barrier at the beginning and at the end if requested. This guarantie
142 * correct request ordering. Empty barrier allow us to avoid post queue flush.
145 int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
146 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags)
151 unsigned int sz, issued = 0;
152 DECLARE_COMPLETION_ONSTACK(wait);
154 atomic_set(&bb.done, 0);
155 bb.flags = 1 << BIO_UPTODATE;
159 if (flags & BLKDEV_IFL_BARRIER) {
160 /* issue async barrier before the data */
161 ret = blkdev_issue_flush(bdev, gfp_mask, NULL, 0);
167 while (nr_sects != 0) {
168 bio = bio_alloc(gfp_mask,
169 min(nr_sects, (sector_t)BIO_MAX_PAGES));
175 bio->bi_sector = sector;
177 bio->bi_end_io = bio_batch_end_io;
178 if (flags & BLKDEV_IFL_WAIT)
179 bio->bi_private = &bb;
181 while (nr_sects != 0) {
182 sz = min((sector_t) PAGE_SIZE >> 9 , nr_sects);
184 /* bio has maximum size possible */
186 ret = bio_add_page(bio, ZERO_PAGE(0), sz << 9, 0);
187 nr_sects -= ret >> 9;
194 submit_bio(WRITE, bio);
197 * When all data bios are in flight. Send final barrier if requeted.
199 if (nr_sects == 0 && flags & BLKDEV_IFL_BARRIER)
200 ret = blkdev_issue_flush(bdev, gfp_mask, NULL,
201 flags & BLKDEV_IFL_WAIT);
204 if (flags & BLKDEV_IFL_WAIT)
205 /* Wait for bios in-flight */
206 while ( issued != atomic_read(&bb.done))
207 wait_for_completion(&wait);
209 if (!test_bit(BIO_UPTODATE, &bb.flags))
210 /* One of bios in the batch was completed with error.*/
216 if (test_bit(BIO_EOPNOTSUPP, &bb.flags)) {
225 EXPORT_SYMBOL(blkdev_issue_zeroout);