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