From nobody Mon Feb 9 04:40:36 2026 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 387D2178CF6; Sun, 24 Mar 2024 23:39:55 +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=1711323596; cv=none; b=dGm+ZzWzPIXlsCZHvUjwoeaj619/yoqRcYHA7jusVLycmlqVkcwfI+c3Xv5ev0J+VSP9sBVC0VaUfrIrRbMz3Hm0WWzO/0vS56CwVZnVKsktsOqIdF9gfqpQOMg8h+WWCms/YaQ3q1cXSnadC6xhtP8dGcSVJAtBmVIv5LJ0vKs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711323596; c=relaxed/simple; bh=0/rB4dEKVbHsJHxiBJ1SGLJ9LMrWWDxyHf0NDmPfMeI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=K0gcGydBxq7icmt63abl1EMT8uO24NmlTdpzoKgYnHmKEdIauWUHbZ0vutppgedKl4ghrT/v524weuRAcMf7TFvGvMMUMGXHpIDEMuEz5gP8KLxDIH9AEfYNzYGezFhORd+v8oqUkb5JZHfWkt0ichI/t+naQhfrn30KktRiM88= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Mns3ab+c; 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="Mns3ab+c" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 55951C43394; Sun, 24 Mar 2024 23:39:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1711323595; bh=0/rB4dEKVbHsJHxiBJ1SGLJ9LMrWWDxyHf0NDmPfMeI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Mns3ab+cjOMkffS/4E/pRYKNp9KyzrWHs5b9VE6VYAkbUUKbrl6FKB4wevhoZF+Vb OvHgAjZJ3OzzE6oqk4d4u1nGXb4v4wEkAa393Z7E0wy5CyIw8zlxxvRXQv00Idw0hR niGKBt0YFWfvNdlr1L4djV2HZ7xJZihnmThEbRhYvtTHYct4ZnKWpHflXkWzuszCwt lsEj4X4OtGx3Bftx14dYY0W/0UhcS2vjuiRwd4SCM4ZGioID+kipvC0HkxT0rRo4HU TTGckESAXMxoQVqEVjSMF+ka02JUDopSRoVf3nsh6AtkBzqIcDwrzQ9Sj81aZLiDrr pItEmRaEyP03Q== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Yewon Choi , Michal Kubiak , Paolo Abeni , Sasha Levin Subject: [PATCH 5.15 301/317] rds: introduce acquire/release ordering in acquire/release_in_xmit() Date: Sun, 24 Mar 2024 19:34:41 -0400 Message-ID: <20240324233458.1352854-302-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240324233458.1352854-1-sashal@kernel.org> References: <20240324233458.1352854-1-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: quoted-printable Content-Type: text/plain; charset="utf-8" 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 d6462d1471c14..85c27d9aa33a3 100644 --- a/net/rds/send.c +++ b/net/rds/send.c @@ -103,13 +103,12 @@ EXPORT_SYMBOL_GPL(rds_send_path_reset); =20 static int acquire_in_xmit(struct rds_conn_path *cp) { - return test_and_set_bit(RDS_IN_XMIT, &cp->cp_flags) =3D=3D 0; + return test_and_set_bit_lock(RDS_IN_XMIT, &cp->cp_flags) =3D=3D 0; } =20 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 --=20 2.43.0