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
;
54 if (!blk_queue_discard(q
))
58 * Ensure that max_discard_sectors is of the proper
61 max_discard_sectors
= min(q
->limits
.max_discard_sectors
, UINT_MAX
>> 9);
62 if (unlikely(!max_discard_sectors
)) {
63 /* Avoid infinite loop below. Being cautious never hurts. */
65 } else 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_UPTODATE
, &bb
.flags
))
115 EXPORT_SYMBOL(blkdev_issue_discard
);
118 * blkdev_issue_zeroout - generate number of zero filed write bios
119 * @bdev: blockdev to issue
120 * @sector: start sector
121 * @nr_sects: number of sectors to write
122 * @gfp_mask: memory allocation flags (for bio_alloc)
125 * Generate and issue number of bios with zerofiled pages.
128 int blkdev_issue_zeroout(struct block_device
*bdev
, sector_t sector
,
129 sector_t nr_sects
, gfp_t gfp_mask
)
135 DECLARE_COMPLETION_ONSTACK(wait
);
137 atomic_set(&bb
.done
, 1);
138 bb
.flags
= 1 << BIO_UPTODATE
;
142 while (nr_sects
!= 0) {
143 bio
= bio_alloc(gfp_mask
,
144 min(nr_sects
, (sector_t
)BIO_MAX_PAGES
));
150 bio
->bi_sector
= sector
;
152 bio
->bi_end_io
= bio_batch_end_io
;
153 bio
->bi_private
= &bb
;
155 while (nr_sects
!= 0) {
156 sz
= min((sector_t
) PAGE_SIZE
>> 9 , nr_sects
);
157 ret
= bio_add_page(bio
, ZERO_PAGE(0), sz
<< 9, 0);
158 nr_sects
-= ret
>> 9;
164 atomic_inc(&bb
.done
);
165 submit_bio(WRITE
, bio
);
168 /* Wait for bios in-flight */
169 if (!atomic_dec_and_test(&bb
.done
))
170 wait_for_completion(&wait
);
172 if (!test_bit(BIO_UPTODATE
, &bb
.flags
))
173 /* One of bios in the batch was completed with error.*/
178 EXPORT_SYMBOL(blkdev_issue_zeroout
);
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