diff options
Diffstat (limited to 'block/bio.c')
| -rw-r--r-- | block/bio.c | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/block/bio.c b/block/bio.c index e726c0e280a8..40f690985bfb 100644 --- a/block/bio.c +++ b/block/bio.c @@ -311,6 +311,40 @@ void bio_reset(struct bio *bio, struct block_device *bdev, blk_opf_t opf) } EXPORT_SYMBOL(bio_reset); +/** + * bio_reuse - reuse a bio with the payload left intact + * @bio: bio to reuse + * @opf: operation and flags for the next I/O + * + * Allow reusing an existing bio for another operation with all set up + * fields including the payload, device and end_io handler left intact. + * + * Typically used when @bio is first used to read data which is then written + * to another location without modification. @bio must not be in-flight and + * owned by the caller. Can't be used for cloned bios. + * + * Note: Can't be used when @bio has integrity or blk-crypto contexts for now. + * Feel free to add that support when you need it, though. + */ +void bio_reuse(struct bio *bio, blk_opf_t opf) +{ + unsigned short vcnt = bio->bi_vcnt, i; + bio_end_io_t *end_io = bio->bi_end_io; + void *private = bio->bi_private; + + WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED)); + WARN_ON_ONCE(bio_integrity(bio)); + WARN_ON_ONCE(bio_has_crypt_ctx(bio)); + + bio_reset(bio, bio->bi_bdev, opf); + for (i = 0; i < vcnt; i++) + bio->bi_iter.bi_size += bio->bi_io_vec[i].bv_len; + bio->bi_vcnt = vcnt; + bio->bi_private = private; + bio->bi_end_io = end_io; +} +EXPORT_SYMBOL_GPL(bio_reuse); + static struct bio *__bio_chain_endio(struct bio *bio) { struct bio *parent = bio->bi_private; |