Root/drivers/md/dm-bio-record.h

1/*
2 * Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved.
3 *
4 * This file is released under the GPL.
5 */
6
7#ifndef DM_BIO_RECORD_H
8#define DM_BIO_RECORD_H
9
10#include <linux/bio.h>
11
12/*
13 * There are lots of mutable fields in the bio struct that get
14 * changed by the lower levels of the block layer. Some targets,
15 * such as multipath, may wish to resubmit a bio on error. The
16 * functions in this file help the target record and restore the
17 * original bio state.
18 */
19
20struct dm_bio_vec_details {
21#if PAGE_SIZE < 65536
22    __u16 bv_len;
23    __u16 bv_offset;
24#else
25    unsigned bv_len;
26    unsigned bv_offset;
27#endif
28};
29
30struct dm_bio_details {
31    sector_t bi_sector;
32    struct block_device *bi_bdev;
33    unsigned int bi_size;
34    unsigned short bi_idx;
35    unsigned long bi_flags;
36    struct dm_bio_vec_details bi_io_vec[BIO_MAX_PAGES];
37};
38
39static inline void dm_bio_record(struct dm_bio_details *bd, struct bio *bio)
40{
41    unsigned i;
42
43    bd->bi_sector = bio->bi_sector;
44    bd->bi_bdev = bio->bi_bdev;
45    bd->bi_size = bio->bi_size;
46    bd->bi_idx = bio->bi_idx;
47    bd->bi_flags = bio->bi_flags;
48
49    for (i = 0; i < bio->bi_vcnt; i++) {
50        bd->bi_io_vec[i].bv_len = bio->bi_io_vec[i].bv_len;
51        bd->bi_io_vec[i].bv_offset = bio->bi_io_vec[i].bv_offset;
52    }
53}
54
55static inline void dm_bio_restore(struct dm_bio_details *bd, struct bio *bio)
56{
57    unsigned i;
58
59    bio->bi_sector = bd->bi_sector;
60    bio->bi_bdev = bd->bi_bdev;
61    bio->bi_size = bd->bi_size;
62    bio->bi_idx = bd->bi_idx;
63    bio->bi_flags = bd->bi_flags;
64
65    for (i = 0; i < bio->bi_vcnt; i++) {
66        bio->bi_io_vec[i].bv_len = bd->bi_io_vec[i].bv_len;
67        bio->bi_io_vec[i].bv_offset = bd->bi_io_vec[i].bv_offset;
68    }
69}
70
71#endif
72

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