From 5cdf2e3fea5ee37b66842d76a9b06e6dac0b933d Mon Sep 17 00:00:00 2001 From: Dennis Zhou Date: Wed, 5 Dec 2018 12:10:31 -0500 Subject: blkcg: associate blkg when associating a device Previously, blkg association was handled by controller specific code in blk-throttle and blk-iolatency. However, because a blkg represents a relationship between a blkcg and a request_queue, it makes sense to keep the blkg->q and bio->bi_disk->queue consistent. This patch moves association into the bio_set_dev macro(). This should cover the majority of cases where the device is set/changed keeping the two pointers consistent. Fallback code is added to blkcg_bio_issue_check() to catch any missing paths. Signed-off-by: Dennis Zhou Reviewed-by: Josef Bacik Signed-off-by: Jens Axboe --- include/linux/bio.h | 2 ++ include/linux/blk-cgroup.h | 18 ++++++++++-------- 2 files changed, 12 insertions(+), 8 deletions(-) (limited to 'include') diff --git a/include/linux/bio.h b/include/linux/bio.h index 62715a5a4f32..6ee2ea8b378a 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -491,12 +491,14 @@ do { \ bio_clear_flag(bio, BIO_THROTTLED);\ (bio)->bi_disk = (bdev)->bd_disk; \ (bio)->bi_partno = (bdev)->bd_partno; \ + bio_associate_blkg(bio); \ } while (0) #define bio_copy_dev(dst, src) \ do { \ (dst)->bi_disk = (src)->bi_disk; \ (dst)->bi_partno = (src)->bi_partno; \ + bio_clone_blkcg_association(dst, src); \ } while (0) #define bio_dev(bio) \ diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h index c08e96e521ed..f09752968c2a 100644 --- a/include/linux/blk-cgroup.h +++ b/include/linux/blk-cgroup.h @@ -21,6 +21,7 @@ #include #include #include +#include /* percpu_counter batch for blkg_[rw]stats, per-cpu drift doesn't matter */ #define BLKG_STAT_CPU_BATCH (INT_MAX / 2) @@ -802,21 +803,23 @@ static inline bool blk_throtl_bio(struct request_queue *q, struct blkcg_gq *blkg static inline bool blkcg_bio_issue_check(struct request_queue *q, struct bio *bio) { - struct blkcg *blkcg; struct blkcg_gq *blkg; bool throtl = false; - rcu_read_lock(); + if (!bio->bi_blkg) { + char b[BDEVNAME_SIZE]; + + WARN_ONCE(1, + "no blkg associated for bio on block-device: %s\n", + bio_devname(bio, b)); + bio_associate_blkg(bio); + } - /* associate blkcg if bio hasn't attached one */ - bio_associate_blkcg(bio, NULL); - blkcg = bio_blkcg(bio); - blkg = blkg_lookup_create(blkcg, q); + blkg = bio->bi_blkg; throtl = blk_throtl_bio(q, blkg, bio); if (!throtl) { - blkg = blkg ?: q->root_blkg; /* * If the bio is flagged with BIO_QUEUE_ENTERED it means this * is a split bio and we would have already accounted for the @@ -828,7 +831,6 @@ static inline bool blkcg_bio_issue_check(struct request_queue *q, blkg_rwstat_add(&blkg->stat_ios, bio->bi_opf, 1); } - rcu_read_unlock(); return !throtl; } -- cgit v1.2.1