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Date: Sat, 1 Sep 2007 08:50:20 +0400
From: Cyrill Gorcunov <gorcunov@gmail.com>
To: LKML <linux-kernel@vger.kernel.org>
Subject: socket locking obscure code
Message-ID: <20070901045020.GA7221@cvg>
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Hi LKML,
 
looking thru lock_sock_nested (while trying to catch
BUG in CIFS as reported on bugzilla #8377) I found
that lock_sock_nested consist of:

void fastcall lock_sock_nested(struct sock *sk, int subclass)
{
	might_sleep();
--->	spin_lock_bh(&sk->sk_lock.slock);
	if (sk->sk_lock.owner)
		__lock_sock(sk);
	sk->sk_lock.owner = (void *)1;
--->	spin_unlock(&sk->sk_lock.slock);
	/*
	 * The sk_lock has mutex_lock() semantics here:
	 */
	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
	local_bh_enable();
}
 
so why spin_unlock are there instead of spin_unlock_bh?
To recope with __lock_sock? Am I right?
 
 		Cyrill