[PATCH 08/12] blkcg: remove bio->bi_css and instead use bio->bi_blkg
From: Dennis Zhou <hidden>
Date: 2018-09-06 21:11:11
Also in:
cgroups, lkml
Subsystem:
block layer, control group - block io controller (blkio), software raid (multiple disks) support, the rest, tracing · Maintainers:
Jens Axboe, Tejun Heo, Josef Bacik, Song Liu, Yu Kuai, Linus Torvalds, Steven Rostedt, Masami Hiramatsu
From: "Dennis Zhou (Facebook)" <redacted> Prior patches ensured that all bios are now associated with some blkg. This now makes bio->bi_css unnecessary as blkg maintains a reference to the blkcg already. This patch removes the field bi_css and transfers corresponding uses to access via bi_blkg. Signed-off-by: Dennis Zhou <redacted> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Acked-by: Tejun Heo <tj@kernel.org> --- block/bio.c | 56 ++++++++------------------------------ block/bounce.c | 2 +- drivers/block/loop.c | 5 ++-- drivers/md/raid0.c | 2 +- include/linux/bio.h | 9 ++---- include/linux/blk-cgroup.h | 8 +++--- include/linux/blk_types.h | 1 - kernel/trace/blktrace.c | 4 +-- 8 files changed, 25 insertions(+), 62 deletions(-)
diff --git a/block/bio.c b/block/bio.c
index 6c69c35db8c7..eb744991d2b1 100644
--- a/block/bio.c
+++ b/block/bio.c@@ -609,7 +609,7 @@ void __bio_clone_fast(struct bio *bio, struct bio *bio_src) bio->bi_iter = bio_src->bi_iter; bio->bi_io_vec = bio_src->bi_io_vec; - bio_clone_blkcg_association(bio, bio_src); + bio_clone_blkg_association(bio, bio_src); blkcg_bio_issue_init(bio); }
@@ -1958,34 +1958,6 @@ EXPORT_SYMBOL(bioset_init_from_src); #ifdef CONFIG_BLK_CGROUP -/** - * bio_associate_blkcg - associate a bio with the specified blkcg - * @bio: target bio - * @blkcg_css: css of the blkcg to associate - * - * Associate @bio with the blkcg specified by @blkcg_css. Block layer will - * treat @bio as if it were issued by a task which belongs to the blkcg. - * - * This function takes an extra reference of @blkcg_css which will be put - * when @bio is released. The caller must own @bio and is responsible for - * synchronizing calls to this function. If @blkcg_css is NULL, a call to - * blkcg_get_css finds the current css from the kthread or task. - */ -int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css) -{ - if (unlikely(bio->bi_css)) - return -EBUSY; - - if (blkcg_css) - css_get(blkcg_css); - else - blkcg_css = blkcg_get_css(); - - bio->bi_css = blkcg_css; - return 0; -} -EXPORT_SYMBOL_GPL(bio_associate_blkcg); - /** * bio_associate_blkg - associate a bio with the specified blkg * @bio: target bio
@@ -2030,7 +2002,6 @@ int bio_associate_blkg_from_css(struct bio *bio, struct cgroup_subsys_state *css) { css_get(css); - bio->bi_css = css; return __bio_associate_blkg_from_css(bio, css); } EXPORT_SYMBOL_GPL(bio_associate_blkg_from_css);
@@ -2051,12 +2022,11 @@ int bio_associate_blkg_from_page(struct bio *bio, struct page *page) { struct cgroup_subsys_state *css; - if (unlikely(bio->bi_css)) + if (unlikely(bio->bi_blkg)) return -EBUSY; if (!page->mem_cgroup) return 0; css = cgroup_get_e_css(page->mem_cgroup->css.cgroup, &io_cgrp_subsys); - bio->bi_css = css; return __bio_associate_blkg_from_css(bio, css); }
@@ -2082,8 +2052,7 @@ int bio_associate_create_blkg(struct request_queue *q, struct bio *bio) rcu_read_lock(); - bio_associate_blkcg(bio, NULL); - blkcg = bio_blkcg(bio); + blkcg = css_to_blkcg(blkcg_get_css()); if (!blkcg->css.parent) { ret = bio_associate_blkg(bio, q->root_blkg);
@@ -2107,30 +2076,27 @@ void bio_disassociate_task(struct bio *bio) put_io_context(bio->bi_ioc); bio->bi_ioc = NULL; } - if (bio->bi_css) { - css_put(bio->bi_css); - bio->bi_css = NULL; - } if (bio->bi_blkg) { + /* a ref is always taken on css */ + css_put(&bio_blkcg(bio)->css); blkg_put(bio->bi_blkg); bio->bi_blkg = NULL; } } /** - * bio_clone_blkcg_association - clone blkcg association from src to dst bio + * bio_clone_blkg_association - clone blkg association from src to dst bio * @dst: destination bio * @src: source bio */ -void bio_clone_blkcg_association(struct bio *dst, struct bio *src) +void bio_clone_blkg_association(struct bio *dst, struct bio *src) { - if (src->bi_css) - WARN_ON(bio_associate_blkcg(dst, src->bi_css)); - - if (src->bi_blkg) + if (src->bi_blkg) { + css_get(&bio_blkcg(src)->css); bio_associate_blkg(dst, src->bi_blkg); + } } -EXPORT_SYMBOL_GPL(bio_clone_blkcg_association); +EXPORT_SYMBOL_GPL(bio_clone_blkg_association); #endif /* CONFIG_BLK_CGROUP */ static void __init biovec_init_slabs(void)
diff --git a/block/bounce.c b/block/bounce.c
index 7a08703b1204..b30071ac4ec6 100644
--- a/block/bounce.c
+++ b/block/bounce.c@@ -257,7 +257,7 @@ static struct bio *bounce_clone_bio(struct bio *bio_src, gfp_t gfp_mask, } } - bio_clone_blkcg_association(bio, bio_src); + bio_clone_blkg_association(bio, bio_src); blkcg_bio_issue_init(bio);
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index ea9debf59b22..abad6d15f956 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c@@ -77,6 +77,7 @@ #include <linux/falloc.h> #include <linux/uio.h> #include <linux/ioprio.h> +#include <linux/blk-cgroup.h> #include "loop.h"
@@ -1760,8 +1761,8 @@ static blk_status_t loop_queue_rq(struct blk_mq_hw_ctx *hctx, /* always use the first bio's css */ #ifdef CONFIG_BLK_CGROUP - if (cmd->use_aio && rq->bio && rq->bio->bi_css) { - cmd->css = rq->bio->bi_css; + if (cmd->use_aio && rq->bio && rq->bio->bi_blkg) { + cmd->css = &bio_blkcg(rq->bio)->css; css_get(cmd->css); } else #endif
diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index ac1cffd2a09b..f3fb5bb8c82a 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c@@ -542,7 +542,7 @@ static void raid0_handle_discard(struct mddev *mddev, struct bio *bio) !discard_bio) continue; bio_chain(discard_bio, bio); - bio_clone_blkcg_association(discard_bio, bio); + bio_clone_blkg_association(discard_bio, bio); if (mddev->gendisk) trace_block_bio_remap(bdev_get_queue(rdev->bdev), discard_bio, disk_devt(mddev->gendisk),
diff --git a/include/linux/bio.h b/include/linux/bio.h
index bd8e67c01aa1..8cb818af09f7 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h@@ -554,24 +554,21 @@ static inline int bio_associate_blkg_from_page(struct bio *bio, #endif #ifdef CONFIG_BLK_CGROUP -int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css); int bio_associate_blkg(struct bio *bio, struct blkcg_gq *blkg); int bio_associate_blkg_from_css(struct bio *bio, struct cgroup_subsys_state *css); int bio_associate_create_blkg(struct request_queue *q, struct bio *bio); void bio_disassociate_task(struct bio *bio); -void bio_clone_blkcg_association(struct bio *dst, struct bio *src); +void bio_clone_blkg_association(struct bio *dst, struct bio *src); #else /* CONFIG_BLK_CGROUP */ -static inline int bio_associate_blkcg(struct bio *bio, - struct cgroup_subsys_state *blkcg_css) { return 0; } static inline int bio_associate_blkg_from_css(struct bio *bio, struct cgroup_subsys_state *css) { return 0; } static inline int bio_associate_create_blkg(struct request_queue *q, struct bio *bio) { return 0; } static inline void bio_disassociate_task(struct bio *bio) { } -static inline void bio_clone_blkcg_association(struct bio *dst, - struct bio *src) { } +static inline void bio_clone_blkg_association(struct bio *dst, + struct bio *src) { } #endif /* CONFIG_BLK_CGROUP */ #ifdef CONFIG_HIGHMEM
diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
index a6b6e741a75e..c41cfcc2b4d8 100644
--- a/include/linux/blk-cgroup.h
+++ b/include/linux/blk-cgroup.h@@ -308,8 +308,8 @@ static inline struct blkcg *css_to_blkcg(struct cgroup_subsys_state *css) */ static inline struct blkcg *__bio_blkcg(struct bio *bio) { - if (bio && bio->bi_css) - return css_to_blkcg(bio->bi_css); + if (bio && bio->bi_blkg) + return bio->bi_blkg->blkcg; return css_to_blkcg(blkcg_css()); }
@@ -323,8 +323,8 @@ static inline struct blkcg *__bio_blkcg(struct bio *bio) */ static inline struct blkcg *bio_blkcg(struct bio *bio) { - if (bio && bio->bi_css) - return css_to_blkcg(bio->bi_css); + if (bio && bio->bi_blkg) + return bio->bi_blkg->blkcg; return NULL; }
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index f6dfb30737d8..9578c7ab1eb6 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h@@ -178,7 +178,6 @@ struct bio { * release. Read comment on top of bio_associate_current(). */ struct io_context *bi_ioc; - struct cgroup_subsys_state *bi_css; struct blkcg_gq *bi_blkg; struct bio_issue bi_issue; #endif
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 2868d85f1fb1..fac0ddf8a8e2 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c@@ -764,9 +764,9 @@ blk_trace_bio_get_cgid(struct request_queue *q, struct bio *bio) if (!bt || !(blk_tracer_flags.val & TRACE_BLK_OPT_CGROUP)) return NULL; - if (!bio->bi_css) + if (!bio->bi_blkg) return NULL; - return cgroup_get_kernfs_id(bio->bi_css->cgroup); + return cgroup_get_kernfs_id(bio_blkcg(bio)->css.cgroup); } #else static union kernfs_node_id *
--
2.17.1