[PATCH AUTOSEL 6.6 06/40] blk-cgroup: bypass blkcg_deactivate_policy after destroying

From: Sasha Levin
Date: Tue Nov 28 2023 - 16:06:59 EST


From: Ming Lei <ming.lei@xxxxxxxxxx>

[ Upstream commit e63a57303599b17290cd8bc48e6f20b24289a8bc ]

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@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20231117023527.3188627-4-ming.lei@xxxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
block/blk-cgroup.c | 13 +++++++++++++
1 file changed, 13 insertions(+)

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 4a42ea2972ad8..4b48c2c440981 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);
}
--
2.42.0