diff options
| -rw-r--r-- | block/bio.c | 61 | ||||
| -rw-r--r-- | include/linux/bio.h | 11 |
2 files changed, 57 insertions, 15 deletions
diff --git a/block/bio.c b/block/bio.c index 2b375020fc49..9e2b33ddca0a 100644 --- a/block/bio.c +++ b/block/bio.c @@ -625,21 +625,20 @@ struct bio *bio_clone_fast(struct bio *bio, gfp_t gfp_mask, struct bio_set *bs) } EXPORT_SYMBOL(bio_clone_fast); -/** - * bio_clone_bioset - clone a bio - * @bio_src: bio to clone - * @gfp_mask: allocation priority - * @bs: bio_set to allocate from - * - * Clone bio. Caller will own the returned bio, but not the actual data it - * points to. Reference count of returned bio will be one. - */ -struct bio *bio_clone_bioset(struct bio *bio_src, gfp_t gfp_mask, - struct bio_set *bs) +static struct bio *__bio_clone_bioset(struct bio *bio_src, gfp_t gfp_mask, + struct bio_set *bs, int offset, + int size) { struct bvec_iter iter; struct bio_vec bv; struct bio *bio; + struct bvec_iter iter_src = bio_src->bi_iter; + + /* for supporting partial clone */ + if (offset || size != bio_src->bi_iter.bi_size) { + bio_advance_iter(bio_src, &iter_src, offset); + iter_src.bi_size = size; + } /* * Pre immutable biovecs, __bio_clone() used to just do a memcpy from @@ -663,7 +662,8 @@ struct bio *bio_clone_bioset(struct bio *bio_src, gfp_t gfp_mask, * __bio_clone_fast() anyways. */ - bio = bio_alloc_bioset(gfp_mask, bio_segments(bio_src), bs); + bio = bio_alloc_bioset(gfp_mask, __bio_segments(bio_src, + &iter_src), bs); if (!bio) return NULL; bio->bi_bdev = bio_src->bi_bdev; @@ -680,7 +680,7 @@ struct bio *bio_clone_bioset(struct bio *bio_src, gfp_t gfp_mask, bio->bi_io_vec[bio->bi_vcnt++] = bio_src->bi_io_vec[0]; break; default: - bio_for_each_segment(bv, bio_src, iter) + __bio_for_each_segment(bv, bio_src, iter, iter_src) bio->bi_io_vec[bio->bi_vcnt++] = bv; break; } @@ -699,9 +699,44 @@ struct bio *bio_clone_bioset(struct bio *bio_src, gfp_t gfp_mask, return bio; } + +/** + * bio_clone_bioset - clone a bio + * @bio_src: bio to clone + * @gfp_mask: allocation priority + * @bs: bio_set to allocate from + * + * Clone bio. Caller will own the returned bio, but not the actual data it + * points to. Reference count of returned bio will be one. + */ +struct bio *bio_clone_bioset(struct bio *bio_src, gfp_t gfp_mask, + struct bio_set *bs) +{ + return __bio_clone_bioset(bio_src, gfp_mask, bs, 0, + bio_src->bi_iter.bi_size); +} EXPORT_SYMBOL(bio_clone_bioset); /** + * bio_clone_bioset_partial - clone a partial bio + * @bio_src: bio to clone + * @gfp_mask: allocation priority + * @bs: bio_set to allocate from + * @offset: cloned starting from the offset + * @size: size for the cloned bio + * + * Clone bio. Caller will own the returned bio, but not the actual data it + * points to. Reference count of returned bio will be one. + */ +struct bio *bio_clone_bioset_partial(struct bio *bio_src, gfp_t gfp_mask, + struct bio_set *bs, int offset, + int size) +{ + return __bio_clone_bioset(bio_src, gfp_mask, bs, offset, size); +} +EXPORT_SYMBOL(bio_clone_bioset_partial); + +/** * bio_add_pc_page - attempt to add page to bio * @q: the target queue * @bio: destination bio diff --git a/include/linux/bio.h b/include/linux/bio.h index 7cf8a6c70a3f..8e521194f6fc 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -183,7 +183,7 @@ static inline void bio_advance_iter(struct bio *bio, struct bvec_iter *iter, #define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len) -static inline unsigned bio_segments(struct bio *bio) +static inline unsigned __bio_segments(struct bio *bio, struct bvec_iter *bvec) { unsigned segs = 0; struct bio_vec bv; @@ -205,12 +205,17 @@ static inline unsigned bio_segments(struct bio *bio) break; } - bio_for_each_segment(bv, bio, iter) + __bio_for_each_segment(bv, bio, iter, *bvec) segs++; return segs; } +static inline unsigned bio_segments(struct bio *bio) +{ + return __bio_segments(bio, &bio->bi_iter); +} + /* * get a reference to a bio, so it won't disappear. the intended use is * something like: @@ -384,6 +389,8 @@ extern void bio_put(struct bio *); extern void __bio_clone_fast(struct bio *, struct bio *); extern struct bio *bio_clone_fast(struct bio *, gfp_t, struct bio_set *); extern struct bio *bio_clone_bioset(struct bio *, gfp_t, struct bio_set *bs); +extern struct bio *bio_clone_bioset_partial(struct bio *, gfp_t, + struct bio_set *, int, int); extern struct bio_set *fs_bio_set; |