From 674b93bd23a2d0fecb1862af72f7d8ac7ec7d6b4 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sun, 24 Jan 2021 11:02:36 +0100 Subject: [PATCH] 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: Christoph Hellwig Acked-by: Tejun Heo Signed-off-by: Jens Axboe --- block/blk-core.c | 5 +++-- include/linux/bio.h | 2 ++ include/linux/blk_types.h | 1 + 3 files changed, 6 insertions(+), 2 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 64f69022de962..1c1b97a82caa2 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -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; /* diff --git a/include/linux/bio.h b/include/linux/bio.h index 12af7aa5db377..2f1155eabaff2 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -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) diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index 8ebd8be3e0508..1bc6f6a01070f 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -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 }; -- 2.39.5