summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorBart Van Assche <bart.vanassche@wdc.com>2018-08-10 23:28:07 +0300
committerJens Axboe <axboe@kernel.dk>2018-08-12 00:41:25 +0300
commitb86d865cb1cae1e61527ea0b8977078bbf694328 (patch)
treee78dcb385ae1f412bea1930a77171a5a39ab1f50
parent46451874c7c9afaa4e014aea0f0970f886444e0d (diff)
downloadlinux-b86d865cb1cae1e61527ea0b8977078bbf694328.tar.xz
blkcg: Make blkg_root_lookup() work for queues in bypass mode
For legacy queues the only call of blkg_root_lookup() happens after bypass mode has been enabled. Since blkg_lookup() returns NULL for queues in bypass mode, modify the blkg_root_lookup() such that it no longer depends on bypass mode. Rename the function into blk_queue_root_blkg() as suggested by Tejun. Suggested-by: Tejun Heo <tj@kernel.org> Fixes: 6bad9b210a22 ("blkcg: Introduce blkg_root_lookup()") Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r--block/blk-sysfs.c2
-rw-r--r--include/linux/blk-cgroup.h15
2 files changed, 6 insertions, 11 deletions
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 380bc284ced1..bb109bb0a055 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -813,7 +813,7 @@ static void __blk_release_queue(struct work_struct *work)
blk_exit_queue(q);
}
- WARN(blkg_root_lookup(q),
+ WARN(blk_queue_root_blkg(q),
"request queue %p is being released but it has not yet been removed from the blkcg controller\n",
q);
diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
index 1361cfc9b878..34aec30e06c7 100644
--- a/include/linux/blk-cgroup.h
+++ b/include/linux/blk-cgroup.h
@@ -342,20 +342,14 @@ static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg,
}
/**
- * blkg_lookup - look up blkg for the specified request queue
+ * blk_queue_root_blkg - return blkg for the (blkcg_root, @q) pair
* @q: request_queue of interest
*
* Lookup blkg for @q at the root level. See also blkg_lookup().
*/
-static inline struct blkcg_gq *blkg_root_lookup(struct request_queue *q)
+static inline struct blkcg_gq *blk_queue_root_blkg(struct request_queue *q)
{
- struct blkcg_gq *blkg;
-
- rcu_read_lock();
- blkg = blkg_lookup(&blkcg_root, q);
- rcu_read_unlock();
-
- return blkg;
+ return q->root_blkg;
}
/**
@@ -881,7 +875,8 @@ static inline bool blk_cgroup_congested(void) { return false; }
static inline void blkcg_schedule_throttle(struct request_queue *q, bool use_memdelay) { }
static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg, void *key) { return NULL; }
-static inline struct blkcg_gq *blkg_root_lookup(struct request_queue *q) { return NULL; }
+static inline struct blkcg_gq *blk_queue_root_blkg(struct request_queue *q)
+{ return NULL; }
static inline int blkcg_init_queue(struct request_queue *q) { return 0; }
static inline void blkcg_drain_queue(struct request_queue *q) { }
static inline void blkcg_exit_queue(struct request_queue *q) { }