Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | */ |
Mikulas Patocka | a920f6b | 2009-04-02 19:55:23 +0100 | [diff] [blame] | 19 | |
| 20 | struct 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 Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 30 | struct dm_bio_details { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 31 | struct block_device *bi_bdev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | unsigned long bi_flags; |
Kent Overstreet | 75d5d81 | 2013-08-07 14:24:19 -0700 | [diff] [blame^] | 33 | struct bvec_iter bi_iter; |
Mikulas Patocka | a920f6b | 2009-04-02 19:55:23 +0100 | [diff] [blame] | 34 | struct dm_bio_vec_details bi_io_vec[BIO_MAX_PAGES]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | }; |
| 36 | |
| 37 | static inline void dm_bio_record(struct dm_bio_details *bd, struct bio *bio) |
| 38 | { |
Mikulas Patocka | a920f6b | 2009-04-02 19:55:23 +0100 | [diff] [blame] | 39 | unsigned i; |
| 40 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | bd->bi_bdev = bio->bi_bdev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | bd->bi_flags = bio->bi_flags; |
Kent Overstreet | 75d5d81 | 2013-08-07 14:24:19 -0700 | [diff] [blame^] | 43 | bd->bi_iter = bio->bi_iter; |
Mikulas Patocka | a920f6b | 2009-04-02 19:55:23 +0100 | [diff] [blame] | 44 | |
| 45 | for (i = 0; i < bio->bi_vcnt; i++) { |
| 46 | bd->bi_io_vec[i].bv_len = bio->bi_io_vec[i].bv_len; |
| 47 | bd->bi_io_vec[i].bv_offset = bio->bi_io_vec[i].bv_offset; |
| 48 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 49 | } |
| 50 | |
| 51 | static inline void dm_bio_restore(struct dm_bio_details *bd, struct bio *bio) |
| 52 | { |
Mikulas Patocka | a920f6b | 2009-04-02 19:55:23 +0100 | [diff] [blame] | 53 | unsigned i; |
| 54 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 55 | bio->bi_bdev = bd->bi_bdev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | bio->bi_flags = bd->bi_flags; |
Kent Overstreet | 75d5d81 | 2013-08-07 14:24:19 -0700 | [diff] [blame^] | 57 | bio->bi_iter = bd->bi_iter; |
Mikulas Patocka | a920f6b | 2009-04-02 19:55:23 +0100 | [diff] [blame] | 58 | |
| 59 | for (i = 0; i < bio->bi_vcnt; i++) { |
| 60 | bio->bi_io_vec[i].bv_len = bd->bi_io_vec[i].bv_len; |
| 61 | bio->bi_io_vec[i].bv_offset = bd->bi_io_vec[i].bv_offset; |
| 62 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 63 | } |
| 64 | |
| 65 | #endif |