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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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 */
Mikulas Patockaa920f6b2009-04-02 19:55:23 +010019
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
Linus Torvalds1da177e2005-04-16 15:20:36 -070030struct 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;
Mikulas Patockaa920f6b2009-04-02 19:55:23 +010036 struct dm_bio_vec_details bi_io_vec[BIO_MAX_PAGES];
Linus Torvalds1da177e2005-04-16 15:20:36 -070037};
38
39static inline void dm_bio_record(struct dm_bio_details *bd, struct bio *bio)
40{
Mikulas Patockaa920f6b2009-04-02 19:55:23 +010041 unsigned i;
42
Linus Torvalds1da177e2005-04-16 15:20:36 -070043 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;
Mikulas Patockaa920f6b2009-04-02 19:55:23 +010048
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 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070053}
54
55static inline void dm_bio_restore(struct dm_bio_details *bd, struct bio *bio)
56{
Mikulas Patockaa920f6b2009-04-02 19:55:23 +010057 unsigned i;
58
Linus Torvalds1da177e2005-04-16 15:20:36 -070059 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;
Mikulas Patockaa920f6b2009-04-02 19:55:23 +010064
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 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070069}
70
71#endif