From 5b83636ae3c3b4f87d02a5929ad4dee831534db0 Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Tue, 4 Sep 2012 15:20:38 -0700 Subject: [PATCH] block: Change bio_split() to respect the current value of bi_idx In the current code bio_split() won't be seeing partially completed bios so this doesn't change any behaviour, but this makes the code a bit clearer as to what bio_split() actually requires. The immediate purpose of the patch is removing unnecessary bi_idx references, but the end goal is to allow partial completed bios to be submitted, which along with immutable biovecs enables effecient bio splitting. Some of the callers were (double) checking that bios could be split, so update their checks too. Signed-off-by: Kent Overstreet CC: Jens Axboe CC: Lars Ellenberg CC: Neil Brown CC: Martin K. Petersen --- drivers/md/raid0.c | 3 +-- drivers/md/raid10.c | 3 +-- fs/bio-integrity.c | 4 ++-- fs/bio.c | 7 +++---- 4 files changed, 7 insertions(+), 10 deletions(-) diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c index 23a38af..fcf65e5 100644 --- a/drivers/md/raid0.c +++ b/drivers/md/raid0.c @@ -527,8 +527,7 @@ static void raid0_make_request(struct mddev *mddev, struct bio *bio) sector_t sector = bio->bi_sector; struct bio_pair *bp; /* Sanity check -- queue functions should prevent this happening */ - if ((bio->bi_vcnt != 1 && bio->bi_vcnt != 0) || - bio->bi_idx != 0) + if (bio_segments(bio) > 1) goto bad_map; /* This is a one page bio that upper layers * refuse to split for us, so we need to split it. diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index 5ee14ab..2e29df9 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -1175,8 +1175,7 @@ static void make_request(struct mddev *mddev, struct bio * bio) || conf->prev.near_copies < conf->prev.raid_disks))) { struct bio_pair *bp; /* Sanity check -- queue functions should prevent this happening */ - if ((bio->bi_vcnt != 1 && bio->bi_vcnt != 0) || - bio->bi_idx != 0) + if (bio_segments(bio) > 1) goto bad_map; /* This is a one page bio that upper layers * refuse to split for us, so we need to split it. diff --git a/fs/bio-integrity.c b/fs/bio-integrity.c index 8c4c604..ca7b02d 100644 --- a/fs/bio-integrity.c +++ b/fs/bio-integrity.c @@ -661,8 +661,8 @@ void bio_integrity_split(struct bio *bio, struct bio_pair *bp, int sectors) bp->bio1.bi_integrity = &bp->bip1; bp->bio2.bi_integrity = &bp->bip2; - bp->iv1 = bip->bip_vec[0]; - bp->iv2 = bip->bip_vec[0]; + bp->iv1 = bip->bip_vec[bip->bip_idx]; + bp->iv2 = bip->bip_vec[bip->bip_idx]; bp->bip1.bip_vec = &bp->iv1; bp->bip2.bip_vec = &bp->iv2; diff --git a/fs/bio.c b/fs/bio.c index 7edc08d..f1b4c16 100644 --- a/fs/bio.c +++ b/fs/bio.c @@ -1620,8 +1620,7 @@ struct bio_pair *bio_split(struct bio *bi, int first_sectors) trace_block_split(bdev_get_queue(bi->bi_bdev), bi, bi->bi_sector + first_sectors); - BUG_ON(bi->bi_vcnt != 1 && bi->bi_vcnt != 0); - BUG_ON(bi->bi_idx != 0); + BUG_ON(bio_segments(bi) > 1); atomic_set(&bp->cnt, 3); bp->error = 0; bp->bio1 = *bi; @@ -1631,8 +1630,8 @@ struct bio_pair *bio_split(struct bio *bi, int first_sectors) bp->bio1.bi_size = first_sectors << 9; if (bi->bi_vcnt != 0) { - bp->bv1 = bi->bi_io_vec[0]; - bp->bv2 = bi->bi_io_vec[0]; + bp->bv1 = *bio_iovec(bi); + bp->bv2 = *bio_iovec(bi); if (bio_is_rw(bi)) { bp->bv2.bv_offset += first_sectors << 9; -- 2.7.4