[PATCH 3/3] blk-cgroup: bypass blkcg_deactivate_policy after destroying

From: Ming Lei <ming.lei@redhat.com>
To: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org, Tejun Heo <tj@kernel.org>,
	Ming Lei <ming.lei@redhat.com>
Subject: [PATCH 3/3] blk-cgroup: bypass blkcg_deactivate_policy after destroying
Date: Fri, 17 Nov 2023 10:35:24 +0800	[thread overview]
Message-ID: <20231117023527.3188627-4-ming.lei@redhat.com> (raw)
In-Reply-To: <20231117023527.3188627-1-ming.lei@redhat.com>

blkcg_deactivate_policy() can be called after blkg_destroy_all()
returns, and it isn't necessary since blkg_destroy_all has covered
policy deactivation.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
 block/blk-cgroup.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 4a42ea2972ad..4b48c2c44098 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -577,6 +577,7 @@ static void blkg_destroy_all(struct gendisk *disk)
 	struct request_queue *q = disk->queue;
 	struct blkcg_gq *blkg, *n;
 	int count = BLKG_DESTROY_BATCH_SIZE;
+	int i;
 
 restart:
 	spin_lock_irq(&q->queue_lock);
@@ -602,6 +603,18 @@ static void blkg_destroy_all(struct gendisk *disk)
 		}
 	}
 
+	/*
+	 * Mark policy deactivated since policy offline has been done, and
+	 * the free is scheduled, so future blkcg_deactivate_policy() can
+	 * be bypassed
+	 */
+	for (i = 0; i < BLKCG_MAX_POLS; i++) {
+		struct blkcg_policy *pol = blkcg_policy[i];
+
+		if (pol)
+			__clear_bit(pol->plid, q->blkcg_pols);
+	}
+
 	q->root_blkg = NULL;
 	spin_unlock_irq(&q->queue_lock);
 }
-- 
2.41.0

