From: Yu Kuai <yukuai3@xxxxxxxxxx>
No functional changes are intended, some drivers like mdraid will split
bio by internal processing, prepare to unify bio split codes.
Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
---
block/blk-merge.c | 60 +++++++++++++++++++++++++++++----------------
include/linux/bio.h | 2 ++
2 files changed, 41 insertions(+), 21 deletions(-)
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 70d704615be5..c45d5e43e172 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -104,35 +104,49 @@ static unsigned int bio_allowed_max_sectors(const struct queue_limits *lim)
return round_down(UINT_MAX, lim->logical_block_size) >> SECTOR_SHIFT;
}
-static struct bio *bio_submit_split(struct bio *bio, int split_sectors)
+/**
+ * bio_submit_split - Submit a bio, splitting it at a designated sector
+ * @bio: the original bio to be submitted and split
+ * @split_sectors: the sector count (from the start of @bio) at which to split
+ * @bs: the bio set used for allocating the new split bio
+ *
+ * The original bio is modified to contain the remaining sectors and submitted.
+ * The caller is responsible for submitting the returned bio.
+ *
+ * If succeed, the newly allocated bio representing the initial part will be
+ * returned, on failure NULL will be returned and original bio will fail.
+ */
+struct bio *bio_submit_split(struct bio *bio, int split_sectors,
+ struct bio_set *bs)
{
+ struct bio *split;
+
if (unlikely(split_sectors < 0))
goto error;
- if (split_sectors) {
- struct bio *split;
+ if (!split_sectors)
+ return bio;
- split = bio_split(bio, split_sectors, GFP_NOIO,
- &bio->bi_bdev->bd_disk->bio_split);
- if (IS_ERR(split)) {
- split_sectors = PTR_ERR(split);
- goto error;
- }
- split->bi_opf |= REQ_NOMERGE;
- blkcg_bio_issue_init(split);
- bio_chain(split, bio);
- trace_block_split(split, bio->bi_iter.bi_sector);
- WARN_ON_ONCE(bio_zone_write_plugging(bio));
- submit_bio_noacct(bio);
- return split;
+ split = bio_split(bio, split_sectors, GFP_NOIO, bs);
+ if (IS_ERR(split)) {
+ split_sectors = PTR_ERR(split);
+ goto error;
}
- return bio;
+ split->bi_opf |= REQ_NOMERGE;
+ blkcg_bio_issue_init(split);
+ bio_chain(split, bio);
+ trace_block_split(split, bio->bi_iter.bi_sector);
+ WARN_ON_ONCE(bio_zone_write_plugging(bio));
+ submit_bio_noacct(bio);
+ return split;
+
error:
bio->bi_status = errno_to_blk_status(split_sectors);
bio_endio(bio);
return NULL;
}
+EXPORT_SYMBOL_GPL(bio_submit_split);
struct bio *bio_split_discard(struct bio *bio, const struct queue_limits *lim,
unsigned *nsegs)
@@ -167,7 +181,8 @@ struct bio *bio_split_discard(struct bio *bio, const struct queue_limits *lim,
if (split_sectors > tmp)
split_sectors -= tmp;
- return bio_submit_split(bio, split_sectors);
+ return bio_submit_split(bio, split_sectors,
+ &bio->bi_bdev->bd_disk->bio_split);
}
static inline unsigned int blk_boundary_sectors(const struct queue_limits *lim,
@@ -357,7 +372,8 @@ struct bio *bio_split_rw(struct bio *bio, const struct queue_limits *lim,
{
return bio_submit_split(bio,
bio_split_rw_at(bio, lim, nr_segs,
- get_max_io_size(bio, lim) << SECTOR_SHIFT));
+ get_max_io_size(bio, lim) << SECTOR_SHIFT),
+ &bio->bi_bdev->bd_disk->bio_split);
}
/*
@@ -376,7 +392,8 @@ struct bio *bio_split_zone_append(struct bio *bio,
lim->max_zone_append_sectors << SECTOR_SHIFT);
if (WARN_ON_ONCE(split_sectors > 0))
split_sectors = -EINVAL;
- return bio_submit_split(bio, split_sectors);
+ return bio_submit_split(bio, split_sectors,
+ &bio->bi_bdev->bd_disk->bio_split);
}
struct bio *bio_split_write_zeroes(struct bio *bio,
@@ -396,7 +413,8 @@ struct bio *bio_split_write_zeroes(struct bio *bio,
return bio;
if (bio_sectors(bio) <= max_sectors)
return bio;
- return bio_submit_split(bio, max_sectors);
+ return bio_submit_split(bio, max_sectors,
+ &bio->bi_bdev->bd_disk->bio_split);
}
/**
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 46ffac5caab7..2233261be5e8 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -324,6 +324,8 @@ extern struct bio *bio_split(struct bio *bio, int sectors,
gfp_t gfp, struct bio_set *bs);
int bio_split_rw_at(struct bio *bio, const struct queue_limits *lim,
unsigned *segs, unsigned max_bytes);
+struct bio *bio_submit_split(struct bio *bio, int split_sectors,
+ struct bio_set *bs);
/**
* bio_next_split - get next @sectors from a bio, splitting if necessary
--
2.39.2
