From: Yu Kuai <yukuai@kernel.org>
To: axboe@kernel.dk, tj@kernel.org, linux-block@vger.kernel.org,
cgroups@vger.kernel.org, nilay@linux.ibm.com, bvanassche@acm.org,
ming.lei@redhat.com, hch@lst.de
Cc: linux-kernel@vger.kernel.org, Yu Kuai <yukuai3@huawei.com>
Subject: [PATCH v2 07/19] mm/page_io: don't nest queue_lock under rcu in bio_associate_blkg_from_page()
Date: Fri, 10 Oct 2025 17:14:32 +0800 [thread overview]
Message-ID: <20251010091446.3048529-8-yukuai@kernel.org> (raw)
In-Reply-To: <20251010091446.3048529-1-yukuai@kernel.org>
From: Yu Kuai <yukuai3@huawei.com>
Prepare to convert protecting blkcg with blkcg_mutex instead of
queue_lock.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
---
mm/page_io.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/mm/page_io.c b/mm/page_io.c
index a2056a5ecb13..4f4cc9370573 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -313,8 +313,13 @@ static void bio_associate_blkg_from_page(struct bio *bio, struct folio *folio)
rcu_read_lock();
css = cgroup_e_css(memcg->css.cgroup, &io_cgrp_subsys);
- bio_associate_blkg_from_css(bio, css);
+ if (!css || !css_tryget_online(css))
+ css = NULL;
rcu_read_unlock();
+
+ bio_associate_blkg_from_css(bio, css);
+ if (css)
+ css_put(css);
}
#else
#define bio_associate_blkg_from_page(bio, folio) do { } while (0)
--
2.51.0
next prev parent reply other threads:[~2025-10-10 9:15 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-10 9:14 [PATCH v2 00/19] blk-cgroup: convert to use blkcg_mutex for protection Yu Kuai
2025-10-10 9:14 ` [PATCH v2 01/19] blk-cgroup: protect iterating blkgs with blkcg->lock in blkcg_print_stat() Yu Kuai
2025-10-10 9:14 ` [PATCH v2 02/19] blk-cgroup: delay freeing policy data after rcu grace period Yu Kuai
2025-10-10 9:14 ` [PATCH v2 03/19] blk-cgroup: don't nest queue_lock under rcu in blkcg_print_blkgs() Yu Kuai
2025-10-10 9:14 ` [PATCH v2 04/19] blk-cgroup: don't nest queue_lock under rcu in blkg_lookup_create() Yu Kuai
2025-10-10 9:14 ` [PATCH v2 05/19] blk-cgroup: don't nest queu_lock under rcu in bio_associate_blkg() Yu Kuai
2025-10-10 9:14 ` [PATCH v2 06/19] blk-cgroup: don't nest queue_lock under blkcg->lock in blkcg_destroy_blkgs() Yu Kuai
2025-10-10 9:14 ` Yu Kuai [this message]
2025-10-10 9:14 ` [PATCH v2 08/19] block, bfq: don't grab queue_lock to initialize bfq Yu Kuai
2025-10-10 9:14 ` [PATCH v2 09/19] blk-cgroup: convert to protect blkgs with blkcg_mutex Yu Kuai
2025-10-10 9:14 ` [PATCH v2 10/19] blk-cgroup: remove radix_tree_preload() Yu Kuai
2025-10-10 9:14 ` [PATCH v2 11/19] blk-cgroup: remove preallocate blkg for blkg_create() Yu Kuai
2025-10-10 9:14 ` [PATCH v2 12/19] blk-throttle: fix possible deadlock due to queue_lock in timer Yu Kuai
2025-10-10 9:14 ` [PATCH v2 13/19] blk-cgroup: add new blkg configuration helpers Yu Kuai
2025-10-10 9:14 ` [PATCH v2 14/19] blk-cgroup: factor out a helper __blkg_activate_policy() Yu Kuai
2025-10-10 9:14 ` [PATCH v2 15/19] blk-throttle: convert to use blkg_conf_{start, end} Yu Kuai
2025-10-10 9:14 ` [PATCH v2 16/19] block, bfq: " Yu Kuai
2025-10-10 9:14 ` [PATCH v2 17/19] blk-iolatency: " Yu Kuai
2025-10-10 9:14 ` [PATCH v2 18/19] blk-iocost: " Yu Kuai
2025-10-10 9:14 ` [PATCH v2 19/19] blk-cgroup: remove unsed blkg configuration helpers Yu Kuai
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