Re: xfrm_policy_kill: inconsistent {softirq-on-W} -> {in-softirq-W} usage

[David Miller <davem@davemloft.net>]

From: Alexey Dobriyan <adobriyan@gmail.com>
Date: Mon, 3 Nov 2008 23:57:26 +0300

> If it's easily reproducible, try this patch:
> 
> --- a/net/xfrm/xfrm_policy.c
> +++ b/net/xfrm/xfrm_policy.c
> @@ -315,9 +315,9 @@ static void xfrm_policy_kill(struct xfrm_policy *policy)

This looks clearly like the correct fix for this lockdep
warning, so I'm adding it to net-2.6 as follows even though
Simon can't readily test it.

Thanks.

commit bbb770e7ab9a436752babfc8765e422d7481be1f
Author: Alexey Dobriyan <adobriyan@gmail.com>
Date:   Mon Nov 3 19:11:29 2008 -0800

    xfrm: Fix xfrm_policy_gc_lock handling.
    
    From: Alexey Dobriyan <adobriyan@gmail.com>
    
    Based upon a lockdep trace by Simon Arlott.
    
    xfrm_policy_kill() can be called from both BH and
    non-BH contexts, so we have to grab xfrm_policy_gc_lock
    with BH disabling.
    
    Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 2587274..058f04f 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -315,9 +315,9 @@ static void xfrm_policy_kill(struct xfrm_policy *policy)
 		return;
 	}
 
-	spin_lock(&xfrm_policy_gc_lock);
+	spin_lock_bh(&xfrm_policy_gc_lock);
 	hlist_add_head(&policy->bydst, &xfrm_policy_gc_list);
-	spin_unlock(&xfrm_policy_gc_lock);
+	spin_unlock_bh(&xfrm_policy_gc_lock);
 
 	schedule_work(&xfrm_policy_gc_work);
 }