netdev - [PATCH] xfrm: don't call xfrm_policy_cache_flush under xfrm_state

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Date:   Wed, 27 Sep 2017 14:25:37 +0200
From:   Artem Savkov <asavkov@...hat.com>
To:     Florian Westphal <fw@...len.de>
Cc:     Steffen Klassert <steffen.klassert@...unet.com>,
        Herbert Xu <herbert@...dor.apana.org.au>,
        "David S . Miller" <davem@...emloft.net>, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org, Artem Savkov <asavkov@...hat.com>
Subject: [PATCH] xfrm: don't call xfrm_policy_cache_flush under xfrm_state_lock

I might be wrong but it doesn't look like xfrm_state_lock is required
for xfrm_policy_cache_flush and calling it under this lock triggers both
"sleeping function called from invalid context" and "possible circular
locking dependency detected" warnings on flush.

Fixes: ec30d78c14a8 xfrm: add xdst pcpu cache
Signed-off-by: Artem Savkov <asavkov@...hat.com>
---
 net/xfrm/xfrm_state.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 0dab1cd79ce4..12213477cd3a 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -732,12 +732,12 @@ int xfrm_state_flush(struct net *net, u8 proto, bool task_valid)
 			}
 		}
 	}
+out:
+	spin_unlock_bh(&net->xfrm.xfrm_state_lock);
 	if (cnt) {
 		err = 0;
 		xfrm_policy_cache_flush();
 	}
-out:
-	spin_unlock_bh(&net->xfrm.xfrm_state_lock);
 	return err;
 }
 EXPORT_SYMBOL(xfrm_state_flush);
-- 
2.13.5