From 210f7cdcf088c304ee0533ffd33d6f71a8821862 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Wed, 15 Mar 2017 14:05:14 +1100 Subject: percpu-refcount: support synchronous switch to atomic mode. percpu_ref_switch_to_atomic_sync() schedules the switch to atomic mode, then waits for it to complete. Also export percpu_ref_switch_to_* so they can be used from modules. This will be used in md/raid to count the number of pending write requests to an array. We occasionally need to check if the count is zero, but most often we don't care. We always want updates to the counter to be fast, as in some cases we count every 4K page. Signed-off-by: NeilBrown Acked-by: Tejun Heo Signed-off-by: Shaohua Li --- include/linux/percpu-refcount.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/percpu-refcount.h b/include/linux/percpu-refcount.h index 3a481a49546e..c13dceb87b60 100644 --- a/include/linux/percpu-refcount.h +++ b/include/linux/percpu-refcount.h @@ -99,6 +99,7 @@ int __must_check percpu_ref_init(struct percpu_ref *ref, void percpu_ref_exit(struct percpu_ref *ref); void percpu_ref_switch_to_atomic(struct percpu_ref *ref, percpu_ref_func_t *confirm_switch); +void percpu_ref_switch_to_atomic_sync(struct percpu_ref *ref); void percpu_ref_switch_to_percpu(struct percpu_ref *ref); void percpu_ref_kill_and_confirm(struct percpu_ref *ref, percpu_ref_func_t *confirm_kill); -- cgit v1.2.3-71-gd317 From 6f8802852f7e58a12177a86179803b9efaad98e2 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Fri, 17 Mar 2017 00:12:29 +0800 Subject: block: introduce bio_copy_data_partial 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 Reviewed-by: Jens Axboe Signed-off-by: Shaohua Li --- block/bio.c | 60 +++++++++++++++++++++++++++++++++++++++++------------ include/linux/bio.h | 2 ++ 2 files changed, 49 insertions(+), 13 deletions(-) (limited to 'include/linux') 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); -- cgit v1.2.3-71-gd317 From f45958756fef552436e4a63029a168495920026e Mon Sep 17 00:00:00 2001 From: Shaohua Li Date: Fri, 24 Mar 2017 10:34:43 -0700 Subject: block: remove bio_clone_bioset_partial() commit c18a1e0(block: introduce bio_clone_bioset_partial()) introduced bio_clone_bioset_partial() for raid1 write behind IO. Now the write behind is rewritten by Ming. We don't need the API any more, so revert the commit. Cc: Christoph Hellwig Reviewed-by: Jens Axboe Reviewed-by: Ming Lei Signed-off-by: Shaohua Li --- block/bio.c | 61 ++++++++++++----------------------------------------- include/linux/bio.h | 11 ++-------- 2 files changed, 15 insertions(+), 57 deletions(-) (limited to 'include/linux') diff --git a/block/bio.c b/block/bio.c index 1ccff0dace89..036435995c55 100644 --- a/block/bio.c +++ b/block/bio.c @@ -631,20 +631,21 @@ struct bio *bio_clone_fast(struct bio *bio, gfp_t gfp_mask, struct bio_set *bs) } EXPORT_SYMBOL(bio_clone_fast); -static struct bio *__bio_clone_bioset(struct bio *bio_src, gfp_t gfp_mask, - struct bio_set *bs, int offset, - int size) +/** + * 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) { 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 @@ -668,8 +669,7 @@ static 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, - &iter_src), bs); + bio = bio_alloc_bioset(gfp_mask, bio_segments(bio_src), bs); if (!bio) return NULL; bio->bi_bdev = bio_src->bi_bdev; @@ -686,7 +686,7 @@ static 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, iter_src) + bio_for_each_segment(bv, bio_src, iter) bio->bi_io_vec[bio->bi_vcnt++] = bv; break; } @@ -705,43 +705,8 @@ static 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 diff --git a/include/linux/bio.h b/include/linux/bio.h index 42b62a0288b0..fafef6343d1b 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, struct bvec_iter *bvec) +static inline unsigned bio_segments(struct bio *bio) { unsigned segs = 0; struct bio_vec bv; @@ -205,17 +205,12 @@ static inline unsigned __bio_segments(struct bio *bio, struct bvec_iter *bvec) break; } - __bio_for_each_segment(bv, bio, iter, *bvec) + bio_for_each_segment(bv, bio, iter) 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: @@ -389,8 +384,6 @@ 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; -- cgit v1.2.3-71-gd317 From 50512625da06c41517cb596f51b923ce15f401a4 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Wed, 5 Apr 2017 14:05:50 +1000 Subject: Revert "block: introduce bio_copy_data_partial" This reverts commit 6f8802852f7e58a12177a86179803b9efaad98e2. bio_copy_data_partial() is no longer needed. Signed-off-by: NeilBrown Signed-off-by: Shaohua Li --- block/bio.c | 60 ++++++++++++----------------------------------------- include/linux/bio.h | 2 -- 2 files changed, 13 insertions(+), 49 deletions(-) (limited to 'include/linux') diff --git a/block/bio.c b/block/bio.c index 036435995c55..12c2837c4277 100644 --- a/block/bio.c +++ b/block/bio.c @@ -990,8 +990,19 @@ int bio_alloc_pages(struct bio *bio, gfp_t gfp_mask) } EXPORT_SYMBOL(bio_alloc_pages); -static void __bio_copy_data(struct bio *dst, struct bio *src, - int offset, int size) +/** + * 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) { struct bvec_iter src_iter, dst_iter; struct bio_vec src_bv, dst_bv; @@ -1001,12 +1012,6 @@ static 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; @@ -1043,47 +1048,8 @@ static 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 fafef6343d1b..7cf8a6c70a3f 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -461,8 +461,6 @@ 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); -- cgit v1.2.3-71-gd317