From: Alasdair G Kergon Simple functions to record and restore bio state so we can resubmit a bio that returned an error. DM multipath (following shortly) uses this. This patch has it private to device-mapper: is it any use elsewhere? Signed-Off-By: Alasdair G Kergon Signed-off-by: Andrew Morton --- 25-akpm/drivers/md/dm-bio-record.h | 45 +++++++++++++++++++++++++++++++++++++ 1 files changed, 45 insertions(+) diff -puN /dev/null drivers/md/dm-bio-record.h --- /dev/null Thu Apr 11 07:25:15 2002 +++ 25-akpm/drivers/md/dm-bio-record.h Wed Feb 9 14:25:12 2005 @@ -0,0 +1,45 @@ +/* + * 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 + +/* + * 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_details { + sector_t bi_sector; + struct block_device *bi_bdev; + unsigned int bi_size; + unsigned short bi_idx; + unsigned long bi_flags; +}; + +static inline void dm_bio_record(struct dm_bio_details *bd, struct bio *bio) +{ + bd->bi_sector = bio->bi_sector; + bd->bi_bdev = bio->bi_bdev; + bd->bi_size = bio->bi_size; + bd->bi_idx = bio->bi_idx; + bd->bi_flags = bio->bi_flags; +} + +static inline void dm_bio_restore(struct dm_bio_details *bd, struct bio *bio) +{ + bio->bi_sector = bd->bi_sector; + bio->bi_bdev = bd->bi_bdev; + bio->bi_size = bd->bi_size; + bio->bi_idx = bd->bi_idx; + bio->bi_flags = bd->bi_flags; +} + +#endif _