aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorDmitry Monakhov2010-04-28 08:55:08 -0500
committerJens Axboe2010-04-28 12:47:36 -0500
commitf31e7e4022841c43c53b847b86b1bf97a08b2c94 (patch)
tree738821236a4e84f790d597bb2cc04bd812668b6a /block/blk-lib.c
parentf17e232e9237c231daf9f0f4b177c61218bcb2e4 (diff)
downloadkernel-common-f31e7e4022841c43c53b847b86b1bf97a08b2c94.tar.gz
kernel-common-f31e7e4022841c43c53b847b86b1bf97a08b2c94.tar.xz
kernel-common-f31e7e4022841c43c53b847b86b1bf97a08b2c94.zip
blkdev: move blkdev_issue helper functions to separate file
Move blkdev_issue_discard from blk-barrier.c because it is not barrier related. Later the file will be populated by other helpers. Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'block/blk-lib.c')
-rw-r--r--block/blk-lib.c114
1 files changed, 114 insertions, 0 deletions
diff --git a/block/blk-lib.c b/block/blk-lib.c
new file mode 100644
index 00000000000..0dc438812d8
--- /dev/null
+++ b/block/blk-lib.c
@@ -0,0 +1,114 @@
1/*
2 * Functions related to generic helpers functions
3 */
4#include <linux/kernel.h>
5#include <linux/module.h>
6#include <linux/bio.h>
7#include <linux/blkdev.h>
8#include <linux/scatterlist.h>
9
10#include "blk.h"
11
12static void blkdev_discard_end_io(struct bio *bio, int err)
13{
14 if (err) {
15 if (err == -EOPNOTSUPP)
16 set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
17 clear_bit(BIO_UPTODATE, &bio->bi_flags);
18 }
19
20 if (bio->bi_private)
21 complete(bio->bi_private);
22 __free_page(bio_page(bio));
23
24 bio_put(bio);
25}
26
27/**
28 * blkdev_issue_discard - queue a discard
29 * @bdev: blockdev to issue discard for
30 * @sector: start sector
31 * @nr_sects: number of sectors to discard
32 * @gfp_mask: memory allocation flags (for bio_alloc)
33 * @flags: BLKDEV_IFL_* flags to control behaviour
34 *
35 * Description:
36 * Issue a discard request for the sectors in question.
37 */
38int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
39 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags)
40{
41 DECLARE_COMPLETION_ONSTACK(wait);
42 struct request_queue *q = bdev_get_queue(bdev);
43 int type = flags & BLKDEV_IFL_BARRIER ?
44 DISCARD_BARRIER : DISCARD_NOBARRIER;
45 struct bio *bio;
46 struct page *page;
47 int ret = 0;
48
49 if (!q)
50 return -ENXIO;
51
52 if (!blk_queue_discard(q))
53 return -EOPNOTSUPP;
54
55 while (nr_sects && !ret) {
56 unsigned int sector_size = q->limits.logical_block_size;
57 unsigned int max_discard_sectors =
58 min(q->limits.max_discard_sectors, UINT_MAX >> 9);
59
60 bio = bio_alloc(gfp_mask, 1);
61 if (!bio)
62 goto out;
63 bio->bi_sector = sector;
64 bio->bi_end_io = blkdev_discard_end_io;
65 bio->bi_bdev = bdev;
66 if (flags & BLKDEV_IFL_WAIT)
67 bio->bi_private = &wait;
68
69 /*
70 * Add a zeroed one-sector payload as that's what
71 * our current implementations need. If we'll ever need
72 * more the interface will need revisiting.
73 */
74 page = alloc_page(gfp_mask | __GFP_ZERO);
75 if (!page)
76 goto out_free_bio;
77 if (bio_add_pc_page(q, bio, page, sector_size, 0) < sector_size)
78 goto out_free_page;
79
80 /*
81 * And override the bio size - the way discard works we
82 * touch many more blocks on disk than the actual payload
83 * length.
84 */
85 if (nr_sects > max_discard_sectors) {
86 bio->bi_size = max_discard_sectors << 9;
87 nr_sects -= max_discard_sectors;
88 sector += max_discard_sectors;
89 } else {
90 bio->bi_size = nr_sects << 9;
91 nr_sects = 0;
92 }
93
94 bio_get(bio);
95 submit_bio(type, bio);
96
97 if (flags & BLKDEV_IFL_WAIT)
98 wait_for_completion(&wait);
99
100 if (bio_flagged(bio, BIO_EOPNOTSUPP))
101 ret = -EOPNOTSUPP;
102 else if (!bio_flagged(bio, BIO_UPTODATE))
103 ret = -EIO;
104 bio_put(bio);
105 }
106 return ret;
107out_free_page:
108 __free_page(page);
109out_free_bio:
110 bio_put(bio);
111out:
112 return -ENOMEM;
113}
114EXPORT_SYMBOL(blkdev_issue_discard);