summaryrefslogtreecommitdiff
path: root/include/linux/blk-cgroup.h
diff options
context:
space:
mode:
authorDennis Zhou <dennis@kernel.org>2018-12-05 20:10:31 +0300
committerJens Axboe <axboe@kernel.dk>2018-12-08 08:26:37 +0300
commit5cdf2e3fea5ee37b66842d76a9b06e6dac0b933d (patch)
treeb460ef1ba02562982e2f000e704ce7214be4d5f3 /include/linux/blk-cgroup.h
parent892ad71f622bbf39c6de321d5ca9b0fdec237c24 (diff)
downloadlinux-5cdf2e3fea5ee37b66842d76a9b06e6dac0b933d.tar.xz
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>
Diffstat (limited to 'include/linux/blk-cgroup.h')
-rw-r--r--include/linux/blk-cgroup.h18
1 files changed, 10 insertions, 8 deletions
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;
}