[PATCH V11 13/19] block: move bounce_clone_bio into bio.c

Ming Lei
2018-11-21T03:28:08Z

We will reuse bounce_clone_bio() for cloning bio in case of
!blk_queue_cluster(q), so move this helper into bio.c and
rename it as bio_clone_bioset().

No function change.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
block/bio.c | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
block/blk.h | 2 ++
block/bounce.c | 70 +---------------------------------------------------------
3 files changed, 72 insertions(+), 69 deletions(-)

diff --git a/block/bio.c b/block/bio.c
index 2680aa42a625..0f1635b9ec50 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -647,6 +647,75 @@ struct bio *bio_clone_fast(struct bio *bio, gfp_t gfp_mask, struct bio_set *bs)
}
EXPORT_SYMBOL(bio_clone_fast);

+/* block core only helper */
+struct bio *bio_clone_bioset(struct bio *bio_src, gfp_t gfp_mask,
+ struct bio_set *bs)
+{
+ struct bvec_iter iter;
+ struct bio_vec bv;
+ struct bio *bio;
+
+ /*
+ * Pre immutable biovecs, __bio_clone() used to just do a memcpy from
+ * bio_src->bi_io_vec to bio->bi_io_vec.
+ *
+ * We can't do that anymore, because:
+ *
+ * - The point of cloning the biovec is to produce a bio with a biovec
+ * the caller can modify: bi_idx and bi_bvec_done should be 0.
+ *
+ * - The original bio could've had more than BIO_MAX_PAGES biovecs; if
+ * we tried to clone the whole thing bio_alloc_bioset() would fail.
+ * But the clone should succeed as long as the number of biovecs we
+ * actually need to allocate is fewer than BIO_MAX_PAGES.
+ *
+ * - Lastly, bi_vcnt should not be looked at or relied upon by code
+ * that does not own the bio - reason being drivers don't use it for
+ * iterating over the biovec anymore, so expecting it to be kept up
+ * to date (i.e. for clones that share the parent biovec) is just
+ * asking for trouble and would force extra work on
+ * __bio_clone_fast() anyways.
+ */
+
+ bio = bio_alloc_bioset(gfp_mask, bio_segments(bio_src), bs);
+ if (!bio)
+ return NULL;
+ bio->bi_disk = bio_src->bi_disk;
+ bio->bi_opf = bio_src->bi_opf;
+ bio->bi_ioprio = bio_src->bi_ioprio;
+ bio->bi_write_hint = bio_src->bi_write_hint;
+ bio->bi_iter.bi_sector = bio_src->bi_iter.bi_sector;
+ bio->bi_iter.bi_size = bio_src->bi_iter.bi_size;
+
+ switch (bio_op(bio)) {
+ case REQ_OP_DISCARD:
+ case REQ_OP_SECURE_ERASE:
+ case REQ_OP_WRITE_ZEROES:
+ break;
+ case REQ_OP_WRITE_SAME:
+ bio->bi_io_vec[bio->bi_vcnt++] = bio_src->bi_io_vec[0];
+ break;
+ default:
+ bio_for_each_segment(bv, bio_src, iter)
+ bio->bi_io_vec[bio->bi_vcnt++] = bv;
+ break;
+ }
+
+ if (bio_integrity(bio_src)) {
+ int ret;
+
+ ret = bio_integrity_clone(bio, bio_src, gfp_mask);
+ if (ret < 0) {
+ bio_put(bio);
+ return NULL;
+ }
+ }
+
+ bio_clone_blkcg_association(bio, bio_src);
+
+ return bio;
+}
+
/**
* bio_add_pc_page - attempt to add page to bio
* @q: the target queue
diff --git a/block/blk.h b/block/blk.h
index 816a9abb87cd..31c0e45aba3a 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -336,6 +336,8 @@ static inline int blk_iolatency_init(struct request_queue *q) { return 0; }

struct bio *blk_next_bio(struct bio *bio, unsigned int nr_pages, gfp_t gfp);

+struct bio *bio_clone_bioset(struct bio *bio_src, gfp_t gfp_mask, struct bio_set *bs);
+
#ifdef CONFIG_BLK_DEV_ZONED
void blk_queue_free_zone_bitmaps(struct request_queue *q);
#else
diff --git a/block/bounce.c b/block/bounce.c
index 7338041e3042..4947c36173b2 100644
--- a/block/bounce.c
+++ b/block/bounce.c
@@ -215,74 +215,6 @@ static void bounce_end_io_read_isa(struct bio *bio)
__bounce_end_io_read(bio, &isa_page_pool);
}

-static struct bio *bounce_clone_bio(struct bio *bio_src, gfp_t gfp_mask,
- struct bio_set *bs)
-{
- struct bvec_iter iter;
- struct bio_vec bv;
- struct bio *bio;
-
- /*
- * Pre immutable biovecs, __bio_clone() used to just do a memcpy from
- * bio_src->bi_io_vec to bio->bi_io_vec.
- *
- * We can't do that anymore, because:
- *
- * - The point of cloning the biovec is to produce a bio with a biovec
- * the caller can modify: bi_idx and bi_bvec_done should be 0.
- *
- * - The original bio could've had more than BIO_MAX_PAGES biovecs; if
- * we tried to clone the whole thing bio_alloc_bioset() would fail.
- * But the clone should succeed as long as the number of biovecs we
- * actually need to allocate is fewer than BIO_MAX_PAGES.
- *
- * - Lastly, bi_vcnt should not be looked at or relied upon by code
- * that does not own the bio - reason being drivers don't use it for
- * iterating over the biovec anymore, so expecting it to be kept up
- * to date (i.e. for clones that share the parent biovec) is just
- * asking for trouble and would force extra work on
- * __bio_clone_fast() anyways.
- */
-
- bio = bio_alloc_bioset(gfp_mask, bio_segments(bio_src), bs);
- if (!bio)
- return NULL;
- bio->bi_disk = bio_src->bi_disk;
- bio->bi_opf = bio_src->bi_opf;
- bio->bi_ioprio = bio_src->bi_ioprio;
- bio->bi_write_hint = bio_src->bi_write_hint;
- bio->bi_iter.bi_sector = bio_src->bi_iter.bi_sector;
- bio->bi_iter.bi_size = bio_src->bi_iter.bi_size;
-
- switch (bio_op(bio)) {
- case REQ_OP_DISCARD:
- case REQ_OP_SECURE_ERASE:
- case REQ_OP_WRITE_ZEROES:
- break;
- case REQ_OP_WRITE_SAME:
- bio->bi_io_vec[bio->bi_vcnt++] = bio_src->bi_io_vec[0];
- break;
- default:
- bio_for_each_segment(bv, bio_src, iter)
- bio->bi_io_vec[bio->bi_vcnt++] = bv;
- break;
- }
-
- if (bio_integrity(bio_src)) {
- int ret;
-
- ret = bio_integrity_clone(bio, bio_src, gfp_mask);
- if (ret < 0) {
- bio_put(bio);
- return NULL;
- }
- }
-
- bio_clone_blkcg_association(bio, bio_src);
-
- return bio;
-}
-
static void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig,
mempool_t *pool)
{
@@ -311,7 +243,7 @@ static void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig,
generic_make_request(*bio_orig);
*bio_orig = bio;
}
- bio = bounce_clone_bio(*bio_orig, GFP_NOIO, passthrough ? NULL :
+ bio = bio_clone_bioset(*bio_orig, GFP_NOIO, passthrough ? NULL :
&bounce_bio_set);

bio_for_each_segment_all(to, bio, i, iter_all) {
--
2.9.5