[PATCH 4/4] blk-iocost: fix stale comment in ioc_rqos_throttle()

[Tao Cui <cui.tao@linux.dev>]

From: Tao Cui <cuitao@kylinos.cn>

The comment says that priority-inversion IOs are "punted to
@ioc->aux_iocg", but no aux_iocg field ever existed in struct ioc.
The comment was introduced already stale by commit da437b95db83
("blk-iocost: grab ioc->lock for debt handling").  Update it to
describe the current use_debt / iocg->abs_vdebt mechanism.

Signed-off-by: Tao Cui <cuitao@kylinos.cn>
---
 block/blk-iocost.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/block/blk-iocost.c b/block/blk-iocost.c
index 1bf622e39ce4..f99c4f5c83fd 100644
--- a/block/blk-iocost.c
+++ b/block/blk-iocost.c
@@ -2748,10 +2748,11 @@ static void ioc_rqos_throttle(struct rq_qos *rqos, struct bio *bio)
 
 	/*
 	 * We're over budget. This can be handled in two ways. IOs which may
-	 * cause priority inversions are punted to @ioc->aux_iocg and charged as
-	 * debt. Otherwise, the issuer is blocked on @iocg->waitq. Debt handling
-	 * requires @ioc->lock, waitq handling @iocg->waitq.lock. Determine
-	 * whether debt handling is needed and acquire locks accordingly.
+	 * cause priority inversions are issued regardless and charged against
+	 * @iocg->abs_vdebt as debt. Otherwise, the issuer is blocked on
+	 * @iocg->waitq. Debt handling requires @ioc->lock, waitq handling
+	 * @iocg->waitq.lock. Determine whether debt handling is needed and
+	 * acquire locks accordingly.
 	 */
 	use_debt = bio_issue_as_root_blkg(bio) || fatal_signal_pending(current);
 	ioc_locked = use_debt || READ_ONCE(iocg->abs_vdebt);
-- 
2.43.0