From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 660631C882D; Sun, 24 Mar 2024 22:46:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711320377; cv=none; b=XoBZ/bkq6+qNxGvJJYhk4jqOGbsQCsQwqJQ5xF8xTmiAtCNjNpL+Bd9QvVpQEe2mcgr9uGPepTmibM0tDH5F9HKYLetVvKN0nJPjgATG6bMOjR06oIj6mvdLmDNYm/HysohMXXBw8yXbImUaaijMoAcnUiuq4b3NvzTrU+ksopQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711320377; c=relaxed/simple; bh=BjRnn2uAci+SuwZsSH8Z6eRxLJRWal9cId1CxlbJEoA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=LWcLtilwOMHuJjOwsTEoDV7Ya8Y77YIeA72BPn5RKbPcmRuf3K6aGCNcdf8ow6O2GlMxs8cyfyfFUTQH8pxcgDAR0+2GHX53vYuDXZx6J7BtcDhT1geCxQ8OIwscZPaxdfkmFlTWVp7kcng71IGYUWVF78eqVNJNNShRBlhkT8w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=BTifkS2l; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="BTifkS2l" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8EBC9C433C7; Sun, 24 Mar 2024 22:46:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1711320377; bh=BjRnn2uAci+SuwZsSH8Z6eRxLJRWal9cId1CxlbJEoA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BTifkS2lkcE1I+4LThq9kKKqqzDtZFPeQvt/zj3VuneeWylGJhbvHPQcTIAEWN4ZL E0nFE86NgfquASokWFoLdbL2MqGxoePqc5o0CqhoZW+t3bya3O0XzhJ2W1rK+wvzbZ hFLKzcsdnpWhM3soUqb0gur/hx8/3109Be+mJ+nKKcBCmD61gL8vD8eGyjRcuWGYev nZxMsJmMAQchugFozC6FEmSNGm2IuA9pAeGc9AvBnc6+io6quhAu69cDwfeoWJS0Gr CvGEXOSZjpPheBA19kG0ey3l0YblA3p8FFOGB5RIjASeplb8MTQ0mfuTPL06UyQIll +u6qBbdnHU5xg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Yewon Choi , Michal Kubiak , Paolo Abeni , Sasha Levin Subject: [PATCH 6.8 683/715] rds: introduce acquire/release ordering in acquire/release_in_xmit() Date: Sun, 24 Mar 2024 18:34:22 -0400 Message-ID: <20240324223455.1342824-684-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240324223455.1342824-1-sashal@kernel.org> References: <20240324223455.1342824-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit From: Yewon Choi [ Upstream commit 1422f28826d2a0c11e5240b3e951c9e214d8656e ] acquire/release_in_xmit() work as bit lock in rds_send_xmit(), so they are expected to ensure acquire/release memory ordering semantics. However, test_and_set_bit/clear_bit() don't imply such semantics, on top of this, following smp_mb__after_atomic() does not guarantee release ordering (memory barrier actually should be placed before clear_bit()). Instead, we use clear_bit_unlock/test_and_set_bit_lock() here. Fixes: 0f4b1c7e89e6 ("rds: fix rds_send_xmit() serialization") Fixes: 1f9ecd7eacfd ("RDS: Pass rds_conn_path to rds_send_xmit()") Signed-off-by: Yewon Choi Reviewed-by: Michal Kubiak Link: https://lore.kernel.org/r/ZfQUxnNTO9AJmzwc@libra05 Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- net/rds/send.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/net/rds/send.c b/net/rds/send.c index 2899def23865f..09a2801106549 100644 --- a/net/rds/send.c +++ b/net/rds/send.c @@ -103,13 +103,12 @@ EXPORT_SYMBOL_GPL(rds_send_path_reset); static int acquire_in_xmit(struct rds_conn_path *cp) { - return test_and_set_bit(RDS_IN_XMIT, &cp->cp_flags) == 0; + return test_and_set_bit_lock(RDS_IN_XMIT, &cp->cp_flags) == 0; } static void release_in_xmit(struct rds_conn_path *cp) { - clear_bit(RDS_IN_XMIT, &cp->cp_flags); - smp_mb__after_atomic(); + clear_bit_unlock(RDS_IN_XMIT, &cp->cp_flags); /* * We don't use wait_on_bit()/wake_up_bit() because our waking is in a * hot path and finding waiters is very rare. We don't want to walk -- 2.43.0