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
;
50 if (!blk_queue_discard(q
))
53 while (nr_sects
&& !ret
) {
54 unsigned int max_discard_sectors
=
55 min(q
->limits
.max_discard_sectors
, UINT_MAX
>> 9);
57 bio
= bio_alloc(gfp_mask
, 1);
63 bio
->bi_sector
= sector
;
64 bio
->bi_end_io
= blkdev_discard_end_io
;
66 if (flags
& BLKDEV_IFL_WAIT
)
67 bio
->bi_private
= &wait
;
69 if (nr_sects
> max_discard_sectors
) {
70 bio
->bi_size
= max_discard_sectors
<< 9;
71 nr_sects
-= max_discard_sectors
;
72 sector
+= max_discard_sectors
;
74 bio
->bi_size
= nr_sects
<< 9;
79 submit_bio(type
, bio
);
81 if (flags
& BLKDEV_IFL_WAIT
)
82 wait_for_completion(&wait
);
84 if (bio_flagged(bio
, BIO_EOPNOTSUPP
))
86 else if (!bio_flagged(bio
, BIO_UPTODATE
))
93 EXPORT_SYMBOL(blkdev_issue_discard
);
99 struct completion
*wait
;
100 bio_end_io_t
*end_io
;
103 static void bio_batch_end_io(struct bio
*bio
, int err
)
105 struct bio_batch
*bb
= bio
->bi_private
;
108 if (err
== -EOPNOTSUPP
)
109 set_bit(BIO_EOPNOTSUPP
, &bb
->flags
);
111 clear_bit(BIO_UPTODATE
, &bb
->flags
);
115 bb
->end_io(bio
, err
);
116 atomic_inc(&bb
->done
);
123 * blkdev_issue_zeroout generate number of zero filed write bios
124 * @bdev: blockdev to issue
125 * @sector: start sector
126 * @nr_sects: number of sectors to write
127 * @gfp_mask: memory allocation flags (for bio_alloc)
128 * @flags: BLKDEV_IFL_* flags to control behaviour
131 * Generate and issue number of bios with zerofiled pages.
132 * Send barrier at the beginning and at the end if requested. This guarantie
133 * correct request ordering. Empty barrier allow us to avoid post queue flush.
136 int blkdev_issue_zeroout(struct block_device
*bdev
, sector_t sector
,
137 sector_t nr_sects
, gfp_t gfp_mask
, unsigned long flags
)
142 unsigned int sz
, issued
= 0;
143 DECLARE_COMPLETION_ONSTACK(wait
);
145 atomic_set(&bb
.done
, 0);
146 bb
.flags
= 1 << BIO_UPTODATE
;
150 if (flags
& BLKDEV_IFL_BARRIER
) {
151 /* issue async barrier before the data */
152 ret
= blkdev_issue_flush(bdev
, gfp_mask
, NULL
, 0);
157 while (nr_sects
!= 0) {
158 bio
= bio_alloc(gfp_mask
,
159 min(nr_sects
, (sector_t
)BIO_MAX_PAGES
));
163 bio
->bi_sector
= sector
;
165 bio
->bi_end_io
= bio_batch_end_io
;
166 if (flags
& BLKDEV_IFL_WAIT
)
167 bio
->bi_private
= &bb
;
169 while (nr_sects
!= 0) {
170 sz
= min((sector_t
) PAGE_SIZE
>> 9 , nr_sects
);
172 /* bio has maximum size possible */
174 ret
= bio_add_page(bio
, ZERO_PAGE(0), sz
<< 9, 0);
175 nr_sects
-= ret
>> 9;
181 submit_bio(WRITE
, bio
);
184 * When all data bios are in flight. Send final barrier if requeted.
186 if (nr_sects
== 0 && flags
& BLKDEV_IFL_BARRIER
)
187 ret
= blkdev_issue_flush(bdev
, gfp_mask
, NULL
,
188 flags
& BLKDEV_IFL_WAIT
);
191 if (flags
& BLKDEV_IFL_WAIT
)
192 /* Wait for bios in-flight */
193 while ( issued
!= atomic_read(&bb
.done
))
194 wait_for_completion(&wait
);
196 if (!test_bit(BIO_UPTODATE
, &bb
.flags
))
197 /* One of bios in the batch was completed with error.*/
203 if (test_bit(BIO_EOPNOTSUPP
, &bb
.flags
)) {
212 EXPORT_SYMBOL(blkdev_issue_zeroout
);
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