| Message ID | 20170316161235.27110-9-tom.leiming@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Jens, can you look at this patch? If it's ok, I'd like to route it through md tree. Thanks, Shaohua On Fri, Mar 17, 2017 at 12:12:29AM +0800, Ming Lei wrote: > Turns out we can use bio_copy_data in raid1's write behind, > and we can make alloc_behind_pages() more clean/efficient, > but we need to partial version of bio_copy_data(). > > Signed-off-by: Ming Lei <tom.leiming@gmail.com> > --- > block/bio.c | 60 +++++++++++++++++++++++++++++++++++++++++------------ > include/linux/bio.h | 2 ++ > 2 files changed, 49 insertions(+), 13 deletions(-) > > diff --git a/block/bio.c b/block/bio.c > index e75878f8b14a..1ccff0dace89 100644 > --- a/block/bio.c > +++ b/block/bio.c > @@ -1025,19 +1025,8 @@ int bio_alloc_pages(struct bio *bio, gfp_t gfp_mask) > } > EXPORT_SYMBOL(bio_alloc_pages); > > -/** > - * bio_copy_data - copy contents of data buffers from one chain of bios to > - * another > - * @src: source bio list > - * @dst: destination bio list > - * > - * If @src and @dst are single bios, bi_next must be NULL - otherwise, treats > - * @src and @dst as linked lists of bios. > - * > - * Stops when it reaches the end of either @src or @dst - that is, copies > - * min(src->bi_size, dst->bi_size) bytes (or the equivalent for lists of bios). > - */ > -void bio_copy_data(struct bio *dst, struct bio *src) > +static void __bio_copy_data(struct bio *dst, struct bio *src, > + int offset, int size) > { > struct bvec_iter src_iter, dst_iter; > struct bio_vec src_bv, dst_bv; > @@ -1047,6 +1036,12 @@ void bio_copy_data(struct bio *dst, struct bio *src) > src_iter = src->bi_iter; > dst_iter = dst->bi_iter; > > + /* for supporting partial copy */ > + if (offset || size != src->bi_iter.bi_size) { > + bio_advance_iter(src, &src_iter, offset); > + src_iter.bi_size = size; > + } > + > while (1) { > if (!src_iter.bi_size) { > src = src->bi_next; > @@ -1083,8 +1078,47 @@ void bio_copy_data(struct bio *dst, struct bio *src) > bio_advance_iter(dst, &dst_iter, bytes); > } > } > + > +/** > + * bio_copy_data - copy contents of data buffers from one chain of bios to > + * another > + * @src: source bio list > + * @dst: destination bio list > + * > + * If @src and @dst are single bios, bi_next must be NULL - otherwise, treats > + * @src and @dst as linked lists of bios. > + * > + * Stops when it reaches the end of either @src or @dst - that is, copies > + * min(src->bi_size, dst->bi_size) bytes (or the equivalent for lists of bios). > + */ > +void bio_copy_data(struct bio *dst, struct bio *src) > +{ > + __bio_copy_data(dst, src, 0, src->bi_iter.bi_size); > +} > EXPORT_SYMBOL(bio_copy_data); > > +/** > + * bio_copy_data_partial - copy partial contents of data buffers from one > + * chain of bios to another > + * @dst: destination bio list > + * @src: source bio list > + * @offset: starting copy from the offset > + * @size: how many bytes to copy > + * > + * If @src and @dst are single bios, bi_next must be NULL - otherwise, treats > + * @src and @dst as linked lists of bios. > + * > + * Stops when it reaches the end of either @src or @dst - that is, copies > + * min(src->bi_size, dst->bi_size) bytes (or the equivalent for lists of bios). > + */ > +void bio_copy_data_partial(struct bio *dst, struct bio *src, > + int offset, int size) > +{ > + __bio_copy_data(dst, src, offset, size); > + > +} > +EXPORT_SYMBOL(bio_copy_data_partial); > + > struct bio_map_data { > int is_our_pages; > struct iov_iter iter; > diff --git a/include/linux/bio.h b/include/linux/bio.h > index 8e521194f6fc..42b62a0288b0 100644 > --- a/include/linux/bio.h > +++ b/include/linux/bio.h > @@ -468,6 +468,8 @@ static inline void bio_flush_dcache_pages(struct bio *bi) > #endif > > extern void bio_copy_data(struct bio *dst, struct bio *src); > +extern void bio_copy_data_partial(struct bio *dst, struct bio *src, > + int offset, int size); > extern int bio_alloc_pages(struct bio *bio, gfp_t gfp); > extern void bio_free_pages(struct bio *bio); > > -- > 2.9.3 >
On 03/16/2017 10:12 AM, Ming Lei wrote: > Turns out we can use bio_copy_data in raid1's write behind, > and we can make alloc_behind_pages() more clean/efficient, > but we need to partial version of bio_copy_data(). > > Signed-off-by: Ming Lei <tom.leiming@gmail.com> Reviewed-by: Jens Axboe <axboe@fb.com> Shaohua, feel free to pull this through the md tree, that will be much easier.
diff --git a/block/bio.c b/block/bio.c index e75878f8b14a..1ccff0dace89 100644 --- a/block/bio.c +++ b/block/bio.c @@ -1025,19 +1025,8 @@ int bio_alloc_pages(struct bio *bio, gfp_t gfp_mask) } EXPORT_SYMBOL(bio_alloc_pages); -/** - * bio_copy_data - copy contents of data buffers from one chain of bios to - * another - * @src: source bio list - * @dst: destination bio list - * - * If @src and @dst are single bios, bi_next must be NULL - otherwise, treats - * @src and @dst as linked lists of bios. - * - * Stops when it reaches the end of either @src or @dst - that is, copies - * min(src->bi_size, dst->bi_size) bytes (or the equivalent for lists of bios). - */ -void bio_copy_data(struct bio *dst, struct bio *src) +static void __bio_copy_data(struct bio *dst, struct bio *src, + int offset, int size) { struct bvec_iter src_iter, dst_iter; struct bio_vec src_bv, dst_bv; @@ -1047,6 +1036,12 @@ void bio_copy_data(struct bio *dst, struct bio *src) src_iter = src->bi_iter; dst_iter = dst->bi_iter; + /* for supporting partial copy */ + if (offset || size != src->bi_iter.bi_size) { + bio_advance_iter(src, &src_iter, offset); + src_iter.bi_size = size; + } + while (1) { if (!src_iter.bi_size) { src = src->bi_next; @@ -1083,8 +1078,47 @@ void bio_copy_data(struct bio *dst, struct bio *src) bio_advance_iter(dst, &dst_iter, bytes); } } + +/** + * bio_copy_data - copy contents of data buffers from one chain of bios to + * another + * @src: source bio list + * @dst: destination bio list + * + * If @src and @dst are single bios, bi_next must be NULL - otherwise, treats + * @src and @dst as linked lists of bios. + * + * Stops when it reaches the end of either @src or @dst - that is, copies + * min(src->bi_size, dst->bi_size) bytes (or the equivalent for lists of bios). + */ +void bio_copy_data(struct bio *dst, struct bio *src) +{ + __bio_copy_data(dst, src, 0, src->bi_iter.bi_size); +} EXPORT_SYMBOL(bio_copy_data); +/** + * bio_copy_data_partial - copy partial contents of data buffers from one + * chain of bios to another + * @dst: destination bio list + * @src: source bio list + * @offset: starting copy from the offset + * @size: how many bytes to copy + * + * If @src and @dst are single bios, bi_next must be NULL - otherwise, treats + * @src and @dst as linked lists of bios. + * + * Stops when it reaches the end of either @src or @dst - that is, copies + * min(src->bi_size, dst->bi_size) bytes (or the equivalent for lists of bios). + */ +void bio_copy_data_partial(struct bio *dst, struct bio *src, + int offset, int size) +{ + __bio_copy_data(dst, src, offset, size); + +} +EXPORT_SYMBOL(bio_copy_data_partial); + struct bio_map_data { int is_our_pages; struct iov_iter iter; diff --git a/include/linux/bio.h b/include/linux/bio.h index 8e521194f6fc..42b62a0288b0 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -468,6 +468,8 @@ static inline void bio_flush_dcache_pages(struct bio *bi) #endif extern void bio_copy_data(struct bio *dst, struct bio *src); +extern void bio_copy_data_partial(struct bio *dst, struct bio *src, + int offset, int size); extern int bio_alloc_pages(struct bio *bio, gfp_t gfp); extern void bio_free_pages(struct bio *bio);
Turns out we can use bio_copy_data in raid1's write behind, and we can make alloc_behind_pages() more clean/efficient, but we need to partial version of bio_copy_data(). Signed-off-by: Ming Lei <tom.leiming@gmail.com> --- block/bio.c | 60 +++++++++++++++++++++++++++++++++++++++++------------ include/linux/bio.h | 2 ++ 2 files changed, 49 insertions(+), 13 deletions(-)