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 A604517DC34; Sun, 24 Mar 2024 23:44:08 +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=1711323848; cv=none; b=RMwnF8dGbjEtkj7UGyeNI8VpWNsCSFF+fJ/L+OUqHMEBl3eYPB3XFx8BXWRjkWq67rj83zs6fDKQJX/b87t0LIQys/yRxj+3kMJI4mrjXHpKxQZ3pIwEHgvGAtAKPSOeHAa+2MIE4KmR2aogCPGBxF4xlVCWBKnLkJc4Zgc3kdQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711323848; c=relaxed/simple; bh=bEmazheCTz8C4a9wAgoygLh8+bNOTAl6eMCuva6xg2c=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=BZScaJ4CcQQ34/L4y44y9tjswQQozoTs1NR5v22NfqVLSIQyfnMyqC27SxbahSm4oVzq65KCpH57DnBKnIEsIcJZRnz2cKg+UDRDj4y6KMoH2AlxwNvxBy5yIGztU5NKluL28VSYjKK1wVAobfTv55s9QGwkv1Y5JXGRiZeaD3s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=BYBylxH6; 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="BYBylxH6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CB128C433F1; Sun, 24 Mar 2024 23:44:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1711323848; bh=bEmazheCTz8C4a9wAgoygLh8+bNOTAl6eMCuva6xg2c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BYBylxH68grao0Wbuq324fokRgsEymM9I47MnMQHUVuKO6bvgKD3Omv3iPlWB3aee F+7Rdatw+izeqASdi+t5HbFfRhJgAYR13EMNJ3bQBdWM0YCBjxb0hfNXX4KyvYMsWz peZ5wQOsTp8hTkWtREptQuVlTIagQvyy8XBaCB9NSmt715p8rEavJJ1GaU06Rqn94T /UWz+S5cZ8HevKIWIAKq7KqRpplgNUhBo6pK1spZv/UxnY/DvJAU6sVjw4JV07zc+Z Wdyo3cChY2AFzo5vLthlYbFkP3wtC2kYHVIbWEXWdQtZhB2QdGv5WUFHAeBS1uOY+2 13t7p0Go/N5oA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Yewon Choi , Michal Kubiak , Paolo Abeni , Sasha Levin Subject: [PATCH 5.10 226/238] rds: introduce acquire/release ordering in acquire/release_in_xmit() Date: Sun, 24 Mar 2024 19:40:14 -0400 Message-ID: <20240324234027.1354210-227-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240324234027.1354210-1-sashal@kernel.org> References: <20240324234027.1354210-1-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 65eeb82cb5de5..1923eaa91e939 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