linux/drivers/md/dm-bio-record.h
Kent Overstreet 75d5d81565 dm: Use bvec_iter for dm_bio_record()
This patch doesn't itself have any functional changes, but immutable
biovecs are going to add a bi_bvec_done member to bi_iter, which will
need to be saved too here.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: dm-devel@redhat.com
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
2013-11-23 22:33:48 -08:00

66 lines
1.4 KiB
C

/*
* Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved.
*
* This file is released under the GPL.
*/
#ifndef DM_BIO_RECORD_H
#define DM_BIO_RECORD_H
#include <linux/bio.h>
/*
* There are lots of mutable fields in the bio struct that get
* changed by the lower levels of the block layer. Some targets,
* such as multipath, may wish to resubmit a bio on error. The
* functions in this file help the target record and restore the
* original bio state.
*/
struct dm_bio_vec_details {
#if PAGE_SIZE < 65536
__u16 bv_len;
__u16 bv_offset;
#else
unsigned bv_len;
unsigned bv_offset;
#endif
};
struct dm_bio_details {
struct block_device *bi_bdev;
unsigned long bi_flags;
struct bvec_iter bi_iter;
struct dm_bio_vec_details bi_io_vec[BIO_MAX_PAGES];
};
static inline void dm_bio_record(struct dm_bio_details *bd, struct bio *bio)
{
unsigned i;
bd->bi_bdev = bio->bi_bdev;
bd->bi_flags = bio->bi_flags;
bd->bi_iter = bio->bi_iter;
for (i = 0; i < bio->bi_vcnt; i++) {
bd->bi_io_vec[i].bv_len = bio->bi_io_vec[i].bv_len;
bd->bi_io_vec[i].bv_offset = bio->bi_io_vec[i].bv_offset;
}
}
static inline void dm_bio_restore(struct dm_bio_details *bd, struct bio *bio)
{
unsigned i;
bio->bi_bdev = bd->bi_bdev;
bio->bi_flags = bd->bi_flags;
bio->bi_iter = bd->bi_iter;
for (i = 0; i < bio->bi_vcnt; i++) {
bio->bi_io_vec[i].bv_len = bd->bi_io_vec[i].bv_len;
bio->bi_io_vec[i].bv_offset = bd->bi_io_vec[i].bv_offset;
}
}
#endif