[PATCH 6/8] userns: Use irqsave variant of refcount_dec_and_lock()

From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: linux-kernel@vger.kernel.org
Cc: tglx@linutronix.de, Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	linux-mm@kvack.org, Shaohua Li <shli@kernel.org>,
	linux-raid@vger.kernel.org,
	Anna-Maria Gleixner <anna-maria@linutronix.de>,
	Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Subject: [PATCH 6/8] userns: Use irqsave variant of refcount_dec_and_lock()
Date: Wed,  9 May 2018 21:36:43 +0200	[thread overview]
Message-ID: <20180509193645.830-7-bigeasy@linutronix.de> (raw)
In-Reply-To: <20180509193645.830-1-bigeasy@linutronix.de>

From: Anna-Maria Gleixner <anna-maria@linutronix.de>

The irqsave variant of refcount_dec_and_lock handles irqsave/restore when
taking/releasing the spin lock. With this variant the call of
local_irq_save/restore is no longer required.

Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
[bigeasy: s@atomic_dec_and_lock@refcount_dec_and_lock@g ]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 kernel/user.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/kernel/user.c b/kernel/user.c
index 5f65ef195259..0df9b1640b2a 100644
--- a/kernel/user.c
+++ b/kernel/user.c
@@ -169,11 +169,8 @@ void free_uid(struct user_struct *up)
 	if (!up)
 		return;
 
-	local_irq_save(flags);
-	if (refcount_dec_and_lock(&up->__count, &uidhash_lock))
+	if (refcount_dec_and_lock_irqsave(&up->__count, &uidhash_lock, &flags))
 		free_user(up, flags);
-	else
-		local_irq_restore(flags);
 }
 
 struct user_struct *alloc_uid(kuid_t uid)
-- 
2.17.0
