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From: Kent Overstreet <koverstreet@google.com>
To: linux-kernel@vger.kernel.org
Cc: Kent Overstreet <koverstreet@google.com>,
	axboe@kernel.dk, Lars Ellenberg <drbd-dev@lists.linbit.com>,
	Neil Brown <neilb@suse.de>,
	"Martin K. Petersen" <martin.petersen@oracle.com>
Subject: [PATCH 10/27] block: Change bio_split() to respect the current value of bi_idx
Date: Tue, 19 Feb 2013 16:22:24 -0800	[thread overview]
Message-ID: <1361319761-23873-11-git-send-email-koverstreet@google.com> (raw)
In-Reply-To: <1361319761-23873-1-git-send-email-koverstreet@google.com>

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 <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: Lars Ellenberg <drbd-dev@lists.linbit.com>
CC: Neil Brown <neilb@suse.de>
CC: Martin K. Petersen <martin.petersen@oracle.com>
---
 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 1ff39e6..0a07239 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -520,8 +520,7 @@ 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 4c6705f..84cd9d7 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1127,8 +1127,7 @@ 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;
-- 
1.7.12


  parent reply	other threads:[~2013-02-20  0:23 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-02-20  0:22 [PATCH 00/27] Block cleanups - prep work for immutable bio vecs/dio rewrite Kent Overstreet
2013-02-20  0:22 ` [PATCH 01/27] block: Reorder struct bio_set Kent Overstreet
2013-02-20  0:22 ` [PATCH 02/27] block: Avoid deadlocks with bio allocation by stacking drivers Kent Overstreet
2013-02-20  0:22 ` [PATCH 03/27] block: Fix a buffer overrun in bio_integrity_split() Kent Overstreet
2013-02-20  0:22 ` [PATCH 04/27] block: Convert integrity to bvec_alloc_bs() Kent Overstreet
2013-05-09 19:43   ` Bjorn Helgaas
2013-02-20  0:22 ` [PATCH 05/27] block: Add bio_advance() Kent Overstreet
2013-02-20  0:22 ` [PATCH 06/27] block: Refactor blk_update_request() Kent Overstreet
2013-02-20  0:22 ` [PATCH 07/27] md: Convert md_trim_bio() to use bio_advance() Kent Overstreet
2013-02-20  0:22 ` [PATCH 08/27] block: Add bio_end_sector() Kent Overstreet
2013-02-20  0:22 ` [PATCH 09/27] block: Use bio_sectors() more consistently Kent Overstreet
2013-02-20 16:43   ` Ed Cashin
2013-02-20  0:22 ` Kent Overstreet [this message]
2013-02-20  0:22 ` [PATCH 11/27] block: Remove bi_idx references Kent Overstreet
2013-02-20  0:22 ` [PATCH 12/27] block: Remove some unnecessary bi_vcnt usage Kent Overstreet
2013-02-20  0:22 ` [PATCH 13/27] block: Add submit_bio_wait(), remove from md Kent Overstreet
2013-02-20  0:22 ` [PATCH 14/27] raid10: Use bio_reset() Kent Overstreet
2013-02-20  0:22 ` [PATCH 15/27] raid1: use bio_reset() Kent Overstreet
2013-02-20  0:22 ` [PATCH 16/27] raid5: " Kent Overstreet
2013-02-20  0:22 ` [PATCH 17/27] raid1: Refactor narrow_write_error() to not use bi_idx Kent Overstreet
2013-02-20  0:22 ` [PATCH 18/27] block: Add bio_copy_data() Kent Overstreet
2013-02-20  0:22 ` [PATCH 19/27] pktcdvd: use bio_copy_data() Kent Overstreet
2013-02-20  0:22 ` [PATCH 20/27] pktcdvd: Use bio_reset() in disabled code to kill bi_idx usage Kent Overstreet
2013-02-20  0:22 ` [PATCH 21/27] raid1: use bio_copy_data() Kent Overstreet
2013-02-20  0:22 ` [PATCH 22/27] bounce: Refactor __blk_queue_bounce to not use bi_io_vec Kent Overstreet
2013-02-20  0:22 ` [PATCH 23/27] block: Add bio_for_each_segment_all() Kent Overstreet
2013-02-20  0:22 ` [PATCH 24/27] block: Convert some code to bio_for_each_segment_all() Kent Overstreet
2013-02-20  0:22 ` [PATCH 25/27] block: Add bio_alloc_pages() Kent Overstreet
2013-02-20  0:22 ` [PATCH 26/27] block: Add an explicit bio flag for bios that own their bvec Kent Overstreet
2013-03-26 18:11   ` Andrew Morton
2013-03-26 19:42     ` Kent Overstreet
2013-02-20  0:22 ` [PATCH 27/27] bio-integrity: Add explicit field for owner of bip_buf Kent Overstreet

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