blk-cgroup: remove blkcg_bio_issue_check

blkcg_bio_issue_check is a giant inline function that does three entirely
different things.  Factor out the blk-cgroup related bio initalization
into a new helper, and the open code the sequence in the only caller,
relying on the fact that all the actual functionality is stubbed out for
non-cgroup builds.

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 2 insertions, 54 deletions

diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
index 8ab043c911f2..431b2d18bf40 100644
--- a/include/linux/blk-cgroup.h
+++ b/include/linux/blk-cgroup.h
@@ -517,14 +517,6 @@ static inline void blkg_put(struct blkcg_gq *blkg)
 		if (((d_blkg) = __blkg_lookup(css_to_blkcg(pos_css),	\
 					      (p_blkg)->q, false)))
 
-#ifdef CONFIG_BLK_DEV_THROTTLING
-extern bool blk_throtl_bio(struct request_queue *q, struct blkcg_gq *blkg,
-			   struct bio *bio);
-#else
-static inline bool blk_throtl_bio(struct request_queue *q, struct blkcg_gq *blkg,
-				  struct bio *bio) { return false; }
-#endif
-
 bool __blkcg_punt_bio_submit(struct bio *bio);
 
 static inline bool blkcg_punt_bio_submit(struct bio *bio)
@@ -540,50 +532,6 @@ static inline void blkcg_bio_issue_init(struct bio *bio)
 	bio_issue_init(&bio->bi_issue, bio_sectors(bio));
 }
 
-static inline bool blkcg_bio_issue_check(struct request_queue *q,
-					 struct bio *bio)
-{
-	struct blkcg_gq *blkg = bio->bi_blkg;
-	bool throtl = false;
-
-	throtl = blk_throtl_bio(q, blkg, bio);
-	if (!throtl) {
-		struct blkg_iostat_set *bis;
-		int rwd, cpu;
-
-		if (op_is_discard(bio->bi_opf))
-			rwd = BLKG_IOSTAT_DISCARD;
-		else if (op_is_write(bio->bi_opf))
-			rwd = BLKG_IOSTAT_WRITE;
-		else
-			rwd = BLKG_IOSTAT_READ;
-
-		cpu = get_cpu();
-		bis = per_cpu_ptr(blkg->iostat_cpu, cpu);
-		u64_stats_update_begin(&bis->sync);
-
-		/*
-		 * If the bio is flagged with BIO_CGROUP_ACCT it means this is a
-		 * split bio and we would have already accounted for the size of
-		 * the bio.
-		 */
-		if (!bio_flagged(bio, BIO_CGROUP_ACCT)) {
-			bio_set_flag(bio, BIO_CGROUP_ACCT);
-			bis->cur.bytes[rwd] += bio->bi_iter.bi_size;
-		}
-		bis->cur.ios[rwd]++;
-
-		u64_stats_update_end(&bis->sync);
-		if (cgroup_subsys_on_dfl(io_cgrp_subsys))
-			cgroup_rstat_updated(blkg->blkcg->css.cgroup, cpu);
-		put_cpu();
-	}
-
-	blkcg_bio_issue_init(bio);
-
-	return !throtl;
-}
-
 static inline void blkcg_use_delay(struct blkcg_gq *blkg)
 {
 	if (WARN_ON_ONCE(atomic_read(&blkg->use_delay) < 0))
@@ -657,6 +605,7 @@ static inline void blkcg_clear_delay(struct blkcg_gq *blkg)
 		atomic_dec(&blkg->blkcg->css.cgroup->congestion_count);
 }
 
+void blk_cgroup_bio_start(struct bio *bio);
 void blkcg_add_delay(struct blkcg_gq *blkg, u64 now, u64 delta);
 void blkcg_schedule_throttle(struct request_queue *q, bool use_memdelay);
 void blkcg_maybe_throttle_current(void);
@@ -710,8 +659,7 @@ static inline void blkg_put(struct blkcg_gq *blkg) { }
 
 static inline bool blkcg_punt_bio_submit(struct bio *bio) { return false; }
 static inline void blkcg_bio_issue_init(struct bio *bio) { }
-static inline bool blkcg_bio_issue_check(struct request_queue *q,
-					 struct bio *bio) { return true; }
+static inline void blk_cgroup_bio_start(struct bio *bio) { }
 
 #define blk_queue_for_each_rl(rl, q)	\
 	for ((rl) = &(q)->root_rl; (rl); (rl) = NULL)