forked from luck/tmp_suning_uos_patched
74d46992e0
This way we don't need a block_device structure to submit I/O. The block_device has different life time rules from the gendisk and request_queue and is usually only available when the block device node is open. Other callers need to explicitly create one (e.g. the lightnvm passthrough code, or the new nvme multipathing code). For the actual I/O path all that we need is the gendisk, which exists once per block device. But given that the block layer also does partition remapping we additionally need a partition index, which is used for said remapping in generic_make_request. Note that all the block drivers generally want request_queue or sometimes the gendisk, so this removes a layer of indirection all over the stack. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
44 lines
1012 B
C
44 lines
1012 B
C
/*
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* Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved.
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*
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* This file is released under the GPL.
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*/
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#ifndef DM_BIO_RECORD_H
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#define DM_BIO_RECORD_H
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#include <linux/bio.h>
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/*
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* There are lots of mutable fields in the bio struct that get
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* changed by the lower levels of the block layer. Some targets,
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* such as multipath, may wish to resubmit a bio on error. The
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* functions in this file help the target record and restore the
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* original bio state.
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*/
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struct dm_bio_details {
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struct gendisk *bi_disk;
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u8 bi_partno;
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unsigned long bi_flags;
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struct bvec_iter bi_iter;
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};
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static inline void dm_bio_record(struct dm_bio_details *bd, struct bio *bio)
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{
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bd->bi_disk = bio->bi_disk;
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bd->bi_partno = bio->bi_partno;
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bd->bi_flags = bio->bi_flags;
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bd->bi_iter = bio->bi_iter;
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}
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static inline void dm_bio_restore(struct dm_bio_details *bd, struct bio *bio)
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{
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bio->bi_disk = bd->bi_disk;
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bio->bi_partno = bd->bi_partno;
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bio->bi_flags = bd->bi_flags;
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bio->bi_iter = bd->bi_iter;
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}
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#endif
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