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* [PATCH AUTOSEL 4.19 01/10] blk-throttle: fix lockdep warning of "cgroup_mutex or RCU read lock required!"
@ 2023-11-28 21:09 Sasha Levin
  2023-11-28 21:09 ` [PATCH AUTOSEL 4.19 02/10] bcache: avoid oversize memory allocation by small stripe_size Sasha Levin
                   ` (8 more replies)
  0 siblings, 9 replies; 10+ messages in thread
From: Sasha Levin @ 2023-11-28 21:09 UTC (permalink / raw)
  To: linux-kernel, stable
  Cc: Ming Lei, Changhui Zhong, Jens Axboe, Sasha Levin, tj, josef,
	cgroups, linux-block

From: Ming Lei <ming.lei@redhat.com>

[ Upstream commit 27b13e209ddca5979847a1b57890e0372c1edcee ]

Inside blkg_for_each_descendant_pre(), both
css_for_each_descendant_pre() and blkg_lookup() requires RCU read lock,
and either cgroup_assert_mutex_or_rcu_locked() or rcu_read_lock_held()
is called.

Fix the warning by adding rcu read lock.

Reported-by: Changhui Zhong <czhong@redhat.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20231117023527.3188627-2-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 block/blk-throttle.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 853b1770df367..e58c03c504c10 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -1383,6 +1383,7 @@ static void tg_conf_updated(struct throtl_grp *tg, bool global)
 		   tg_bps_limit(tg, READ), tg_bps_limit(tg, WRITE),
 		   tg_iops_limit(tg, READ), tg_iops_limit(tg, WRITE));
 
+	rcu_read_lock();
 	/*
 	 * Update has_rules[] flags for the updated tg's subtree.  A tg is
 	 * considered to have rules if either the tg itself or any of its
@@ -1410,6 +1411,7 @@ static void tg_conf_updated(struct throtl_grp *tg, bool global)
 		this_tg->latency_target = max(this_tg->latency_target,
 				parent_tg->latency_target);
 	}
+	rcu_read_unlock();
 
 	/*
 	 * We're already holding queue_lock and know @tg is valid.  Let's
-- 
2.42.0


^ permalink raw reply related	[flat|nested] 10+ messages in thread

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Thread overview: 10+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2023-11-28 21:09 [PATCH AUTOSEL 4.19 01/10] blk-throttle: fix lockdep warning of "cgroup_mutex or RCU read lock required!" Sasha Levin
2023-11-28 21:09 ` [PATCH AUTOSEL 4.19 02/10] bcache: avoid oversize memory allocation by small stripe_size Sasha Levin
2023-11-28 21:09 ` [PATCH AUTOSEL 4.19 03/10] bcache: add code comments for bch_btree_node_get() and __bch_btree_node_alloc() Sasha Levin
2023-11-28 21:09 ` [PATCH AUTOSEL 4.19 04/10] bcache: avoid NULL checking to c->root in run_cache_set() Sasha Levin
2023-11-28 21:09 ` [PATCH AUTOSEL 4.19 05/10] platform/x86: intel_telemetry: Fix kernel doc descriptions Sasha Levin
2023-11-28 21:09 ` [PATCH AUTOSEL 4.19 06/10] HID: add ALWAYS_POLL quirk for Apple kb Sasha Levin
2023-11-28 21:09 ` [PATCH AUTOSEL 4.19 07/10] HID: hid-asus: reset the backlight brightness level on resume Sasha Levin
2023-11-28 21:09 ` [PATCH AUTOSEL 4.19 08/10] HID: multitouch: Add quirk for HONOR GLO-GXXX touchpad Sasha Levin
2023-11-28 21:09 ` [PATCH AUTOSEL 4.19 09/10] asm-generic: qspinlock: fix queued_spin_value_unlocked() implementation Sasha Levin
2023-11-28 21:09 ` [PATCH AUTOSEL 4.19 10/10] net: usb: qmi_wwan: claim interface 4 for ZTE MF290 Sasha Levin

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