diff options
author | Dennis Zhou <dennis@kernel.org> | 2018-12-05 12:10:31 -0500 |
---|---|---|
committer | Jens Axboe <axboe@kernel.dk> | 2018-12-07 22:26:37 -0700 |
commit | 5cdf2e3fea5ee37b66842d76a9b06e6dac0b933d (patch) | |
tree | b460ef1ba02562982e2f000e704ce7214be4d5f3 | |
parent | 892ad71f622bbf39c6de321d5ca9b0fdec237c24 (diff) |
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 <dennis@kernel.org>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r-- | block/bio.c | 1 | ||||
-rw-r--r-- | block/blk-iolatency.c | 4 | ||||
-rw-r--r-- | block/blk-throttle.c | 1 | ||||
-rw-r--r-- | include/linux/bio.h | 2 | ||||
-rw-r--r-- | include/linux/blk-cgroup.h | 18 |
5 files changed, 14 insertions, 12 deletions
diff --git a/block/bio.c b/block/bio.c index 41ebb3f8e2fc..1e852ab904aa 100644 --- a/block/bio.c +++ b/block/bio.c @@ -2074,6 +2074,7 @@ void bio_associate_blkg(struct bio *bio) rcu_read_unlock(); } +EXPORT_SYMBOL_GPL(bio_associate_blkg); /** * bio_disassociate_task - undo bio_associate_current() diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c index cdbd10564e66..e6b47c255521 100644 --- a/block/blk-iolatency.c +++ b/block/blk-iolatency.c @@ -472,14 +472,12 @@ static void check_scale_change(struct iolatency_grp *iolat) static void blkcg_iolatency_throttle(struct rq_qos *rqos, struct bio *bio) { struct blk_iolatency *blkiolat = BLKIOLATENCY(rqos); - struct blkcg_gq *blkg; + struct blkcg_gq *blkg = bio->bi_blkg; bool issue_as_root = bio_issue_as_root_blkg(bio); if (!blk_iolatency_enabled(blkiolat)) return; - bio_associate_blkg(bio); - blkg = bio->bi_blkg; bio_issue_init(&bio->bi_issue, bio_sectors(bio)); while (blkg && blkg->parent) { diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 228c3a007ebc..1c6529df2002 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -2118,7 +2118,6 @@ static inline void throtl_update_latency_buckets(struct throtl_data *td) static void blk_throtl_assoc_bio(struct bio *bio) { #ifdef CONFIG_BLK_DEV_THROTTLING_LOW - bio_associate_blkg(bio); bio_issue_init(&bio->bi_issue, bio_sectors(bio)); #endif } 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 <linux/blkdev.h> #include <linux/atomic.h> #include <linux/kthread.h> +#include <linux/fs.h> /* 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; } |