Commit fd8f8ede authored by Christoph Hellwig's avatar Christoph Hellwig Committed by David Sterba
Browse files

block: export bio_split_rw 



bio_split_rw can be used by file systems to split and incoming write
bio into multiple bios fitting the hardware limit for use as ZONE_APPEND
bios.  Export it for initial use in btrfs.

Reviewed-by: default avatarJosef Bacik <josef@toxicpanda.com>
Reviewed-by: default avatarChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent c9a43aaf

block/blk-merge.c

+2 −1
Original line number Diff line number Diff line
@@ -276,7 +276,7 @@ static bool bvec_split_segs(const struct queue_limits *lim, 
 * responsible for ensuring that @bs is only destroyed after processing of the

 * split bio has finished.

 */

static struct bio *bio_split_rw(struct bio *bio, const struct queue_limits *lim,

struct bio *bio_split_rw(struct bio *bio, const struct queue_limits *lim,

		unsigned *segs, struct bio_set *bs, unsigned max_bytes)

{

	struct bio_vec bv, bvprv, *bvprvp = NULL;
@@ -336,6 +336,7 @@ static struct bio *bio_split_rw(struct bio *bio, const struct queue_limits *lim, 
	bio_clear_polled(bio);

	return bio_split(bio, bytes >> SECTOR_SHIFT, GFP_NOIO, bs);

}

EXPORT_SYMBOL_GPL(bio_split_rw);



/**

 * __bio_split_to_limits - split a bio to fit the queue limits

include/linux/bio.h

+4 −0
Original line number Diff line number Diff line
@@ -12,6 +12,8 @@ 


#define BIO_MAX_VECS		256U



struct queue_limits;



static inline unsigned int bio_max_segs(unsigned int nr_segs)

{

	return min(nr_segs, BIO_MAX_VECS);
@@ -375,6 +377,8 @@ static inline void bip_set_seed(struct bio_integrity_payload *bip, 
void bio_trim(struct bio *bio, sector_t offset, sector_t size);

extern struct bio *bio_split(struct bio *bio, int sectors,

			     gfp_t gfp, struct bio_set *bs);

struct bio *bio_split_rw(struct bio *bio, const struct queue_limits *lim,

		unsigned *segs, struct bio_set *bs, unsigned max_bytes);



/**

 * bio_next_split - get next @sectors from a bio, splitting if necessary