[PATCH V10 02/19] block: introduce bio_for_each_bvec()
From: Ming Lei <hidden>
Date: 2018-11-15 08:52:49
Also in:
dm-devel, linux-bcache, linux-block, linux-btrfs, linux-ext4, linux-fsdevel, linux-mm, linux-xfs, lkml
Subsystem:
block layer, the rest · Maintainers:
Jens Axboe, Linus Torvalds
This helper is used for iterating over multi-page bvec for bio split & merge code. Cc: Dave Chinner <redacted> Cc: Kent Overstreet <redacted> Cc: Mike Snitzer <redacted> Cc: dm-devel@redhat.com Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Cc: Shaohua Li <shli@kernel.org> Cc: linux-raid@vger.kernel.org Cc: linux-erofs@lists.ozlabs.org Cc: David Sterba <dsterba@suse.com> Cc: linux-btrfs@vger.kernel.org Cc: Darrick J. Wong <redacted> Cc: linux-xfs@vger.kernel.org Cc: Gao Xiang <redacted> Cc: Christoph Hellwig <hch@lst.de> Cc: Theodore Ts'o <tytso@mit.edu> Cc: linux-ext4@vger.kernel.org Cc: Coly Li <redacted> Cc: linux-bcache@vger.kernel.org Cc: Boaz Harrosh <redacted> Cc: Bob Peterson <redacted> Cc: cluster-devel@redhat.com Signed-off-by: Ming Lei <redacted> --- include/linux/bio.h | 34 +++++++++++++++++++++++++++++++--- include/linux/bvec.h | 36 ++++++++++++++++++++++++++++++++---- 2 files changed, 63 insertions(+), 7 deletions(-)
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 056fb627edb3..1f0dcf109841 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h@@ -76,6 +76,9 @@ #define bio_data_dir(bio) \ (op_is_write(bio_op(bio)) ? WRITE : READ) +#define bio_iter_mp_iovec(bio, iter) \ + mp_bvec_iter_bvec((bio)->bi_io_vec, (iter)) + /* * Check whether this bio carries any data or not. A NULL bio is allowed. */
@@ -135,18 +138,33 @@ static inline bool bio_full(struct bio *bio) #define bio_for_each_segment_all(bvl, bio, i) \ for (i = 0, bvl = (bio)->bi_io_vec; i < (bio)->bi_vcnt; i++, bvl++) -static inline void bio_advance_iter(struct bio *bio, struct bvec_iter *iter, - unsigned bytes) +static inline void __bio_advance_iter(struct bio *bio, struct bvec_iter *iter, + unsigned bytes, bool mp) { iter->bi_sector += bytes >> 9; if (bio_no_advance_iter(bio)) iter->bi_size -= bytes; else - bvec_iter_advance(bio->bi_io_vec, iter, bytes); + if (!mp) + bvec_iter_advance(bio->bi_io_vec, iter, bytes); + else + mp_bvec_iter_advance(bio->bi_io_vec, iter, bytes); /* TODO: It is reasonable to complete bio with error here. */ } +static inline void bio_advance_iter(struct bio *bio, struct bvec_iter *iter, + unsigned bytes) +{ + __bio_advance_iter(bio, iter, bytes, false); +} + +static inline void bio_advance_mp_iter(struct bio *bio, struct bvec_iter *iter, + unsigned bytes) +{ + __bio_advance_iter(bio, iter, bytes, true); +} + #define __bio_for_each_segment(bvl, bio, iter, start) \ for (iter = (start); \ (iter).bi_size && \
@@ -156,6 +174,16 @@ static inline void bio_advance_iter(struct bio *bio, struct bvec_iter *iter, #define bio_for_each_segment(bvl, bio, iter) \ __bio_for_each_segment(bvl, bio, iter, (bio)->bi_iter) +#define __bio_for_each_bvec(bvl, bio, iter, start) \ + for (iter = (start); \ + (iter).bi_size && \ + ((bvl = bio_iter_mp_iovec((bio), (iter))), 1); \ + bio_advance_mp_iter((bio), &(iter), (bvl).bv_len)) + +/* returns one real segment(multipage bvec) each time */ +#define bio_for_each_bvec(bvl, bio, iter) \ + __bio_for_each_bvec(bvl, bio, iter, (bio)->bi_iter) + #define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len) static inline unsigned bio_segments(struct bio *bio)
diff --git a/include/linux/bvec.h b/include/linux/bvec.h
index 8ef904a50577..3d61352cd8cf 100644
--- a/include/linux/bvec.h
+++ b/include/linux/bvec.h@@ -124,8 +124,16 @@ struct bvec_iter { .bv_offset = bvec_iter_offset((bvec), (iter)), \ }) -static inline bool bvec_iter_advance(const struct bio_vec *bv, - struct bvec_iter *iter, unsigned bytes) +#define mp_bvec_iter_bvec(bvec, iter) \ +((struct bio_vec) { \ + .bv_page = mp_bvec_iter_page((bvec), (iter)), \ + .bv_len = mp_bvec_iter_len((bvec), (iter)), \ + .bv_offset = mp_bvec_iter_offset((bvec), (iter)), \ +}) + +static inline bool __bvec_iter_advance(const struct bio_vec *bv, + struct bvec_iter *iter, + unsigned bytes, bool mp) { if (WARN_ONCE(bytes > iter->bi_size, "Attempted to advance past end of bvec iter\n")) {
@@ -134,8 +142,14 @@ static inline bool bvec_iter_advance(const struct bio_vec *bv, } while (bytes) { - unsigned iter_len = bvec_iter_len(bv, *iter); - unsigned len = min(bytes, iter_len); + unsigned len; + + if (mp) + len = mp_bvec_iter_len(bv, *iter); + else + len = bvec_iter_len(bv, *iter); + + len = min(bytes, len); bytes -= len; iter->bi_size -= len;
@@ -173,6 +187,20 @@ static inline bool bvec_iter_rewind(const struct bio_vec *bv, return true; } +static inline bool bvec_iter_advance(const struct bio_vec *bv, + struct bvec_iter *iter, + unsigned bytes) +{ + return __bvec_iter_advance(bv, iter, bytes, false); +} + +static inline bool mp_bvec_iter_advance(const struct bio_vec *bv, + struct bvec_iter *iter, + unsigned bytes) +{ + return __bvec_iter_advance(bv, iter, bytes, true); +} + #define for_each_bvec(bvl, bio_vec, iter, start) \ for (iter = (start); \ (iter).bi_size && \
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2.9.5