Commit 30c5d345 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

block: do not reassig ->bi_bdev when partition remapping 



There is no good reason to reassign ->bi_bdev when remapping the
partition-relative block number to the device wide one, as all the
information required by the drivers comes from the gendisk anyway.

Keeping the original ->bi_bdev alive will allow to greatly simplify
the partition-away I/O accounting.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Acked-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 2f9f6221

block/blk-core.c

+3 −2
Original line number Diff line number Diff line
@@ -752,7 +752,7 @@ static int blk_partition_remap(struct bio *bio) 
				      bio->bi_iter.bi_sector -

				      p->bd_start_sect);

	}

	bio->bi_bdev = bdev_whole(p);

	bio_set_flag(bio, BIO_REMAPPED);

	return 0;

}
@@ -817,7 +817,8 @@ static noinline_for_stack bool submit_bio_checks(struct bio *bio) 
		goto end_io;

	if (unlikely(bio_check_eod(bio)))

		goto end_io;

	if (bio->bi_bdev->bd_partno && unlikely(blk_partition_remap(bio)))

	if (bio->bi_bdev->bd_partno && !bio_flagged(bio, BIO_REMAPPED) &&

	    unlikely(blk_partition_remap(bio)))

		goto end_io;



	/*

include/linux/bio.h

+2 −0
Original line number Diff line number Diff line
@@ -485,6 +485,7 @@ extern const char *bio_devname(struct bio *bio, char *buffer); 


#define bio_set_dev(bio, bdev) 				\

do {							\

	bio_clear_flag(bio, BIO_REMAPPED);		\

	if ((bio)->bi_bdev != (bdev))			\

		bio_clear_flag(bio, BIO_THROTTLED);	\

	(bio)->bi_bdev = (bdev);			\
@@ -493,6 +494,7 @@ do { \ 


#define bio_copy_dev(dst, src)			\

do {						\

	bio_clear_flag(dst, BIO_REMAPPED);		\

	(dst)->bi_bdev = (src)->bi_bdev;	\

	bio_clone_blkg_association(dst, src);	\

} while (0)

include/linux/blk_types.h

+1 −0
Original line number Diff line number Diff line
@@ -303,6 +303,7 @@ enum { 
				 * of this bio. */

	BIO_CGROUP_ACCT,	/* has been accounted to a cgroup */

	BIO_TRACKED,		/* set if bio goes through the rq_qos path */

	BIO_REMAPPED,

	BIO_FLAG_LAST

};