Re: [PATCH net 2/4] tls: Fix write space handling

[Boris Pismenny <borisp@mellanox.com>]

On 2/26/2019 2:49 PM, Vakul Garg wrote:
> 
> 
>> -----Original Message-----
>> From: Boris Pismenny <borisp@mellanox.com>
>> Sent: Tuesday, February 26, 2019 5:43 PM
>> To: aviadye@mellanox.com; davejwatson@fb.com;
>> john.fastabend@gmail.com; daniel@iogearbox.net; Vakul Garg
>> <vakul.garg@nxp.com>; netdev@vger.kernel.org
>> Cc: eranbe@mellanox.com; borisp@mellanox.com
>> Subject: [PATCH net 2/4] tls: Fix write space handling
>>
>> TLS device cannot use the sw context. This patch returns the original
>> tls device write space handler and moves the sw/device specific portions
>> to the relevant files.
>>
>> Fixes: a42055e8d2c3 ("net/tls: Add support for async encryption of records
>> for performance")
>> Signed-off-by: Boris Pismenny <borisp@mellanox.com>
>> Reviewed-by: Eran Ben Elisha <eranbe@mellanox.com>
>> ---
>>   include/net/tls.h    |  3 +++
>>   net/tls/tls_device.c | 16 ++++++++++++++++
>>   net/tls/tls_main.c   | 17 +++++++++--------
>>   net/tls/tls_sw.c     | 15 +++++++++++++++
>>   4 files changed, 43 insertions(+), 8 deletions(-)
>>
>> diff --git a/include/net/tls.h b/include/net/tls.h
>> index a528a082da73..9d7c53737b13 100644
>> --- a/include/net/tls.h
>> +++ b/include/net/tls.h
>> @@ -519,6 +519,9 @@ static inline bool tls_sw_has_ctx_tx(const struct sock
>> *sk)
>>   	return !!tls_sw_ctx_tx(ctx);
>>   }
>>
>> +int tls_sw_write_space(struct sock *sk, struct tls_context *ctx);
>> +int tls_device_write_space(struct sock *sk, struct tls_context *ctx);
>> +
>>   static inline struct tls_offload_context_rx *
>>   tls_offload_ctx_rx(const struct tls_context *tls_ctx)
>>   {
>> diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c
>> index 3e5e8e021a87..e8988b3f3236 100644
>> --- a/net/tls/tls_device.c
>> +++ b/net/tls/tls_device.c
>> @@ -546,6 +546,22 @@ static int tls_device_push_pending_record(struct
>> sock *sk, int flags)
>>   	return tls_push_data(sk, &msg_iter, 0, flags,
>> TLS_RECORD_TYPE_DATA);
>>   }
>>
>> +int tls_device_write_space(struct sock *sk, struct tls_context *ctx)
>> +{
>> +	int rc = 0;
>> +
>> +	if (!sk->sk_write_pending && tls_is_partially_sent_record(ctx)) {
>> +		gfp_t sk_allocation = sk->sk_allocation;
>> +
>> +		sk->sk_allocation = GFP_ATOMIC;
>> +		rc = tls_push_partial_record(sk, ctx,
>> +					     MSG_DONTWAIT |
>> MSG_NOSIGNAL);
>> +		sk->sk_allocation = sk_allocation;
>> +	}
>> +
>> +	return rc;
>> +}
>> +
>>   void handle_device_resync(struct sock *sk, u32 seq, u64 rcd_sn)
>>   {
>>   	struct tls_context *tls_ctx = tls_get_ctx(sk);
>> diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c
>> index 7e05af75536d..11c1980a75cb 100644
>> --- a/net/tls/tls_main.c
>> +++ b/net/tls/tls_main.c
>> @@ -212,7 +212,7 @@ int tls_push_partial_record(struct sock *sk, struct
>> tls_context *ctx,
>>   static void tls_write_space(struct sock *sk)
>>   {
>>   	struct tls_context *ctx = tls_get_ctx(sk);
>> -	struct tls_sw_context_tx *tx_ctx = tls_sw_ctx_tx(ctx);
>> +	int rc;
>>
>>   	/* If in_tcp_sendpages call lower protocol write space handler
>>   	 * to ensure we wake up any waiting operations there. For example
>> @@ -223,14 +223,15 @@ static void tls_write_space(struct sock *sk)
>>   		return;
>>   	}
>>
>> -	/* Schedule the transmission if tx list is ready */
>> -	if (is_tx_ready(tx_ctx) && !sk->sk_write_pending) {
>> -		/* Schedule the transmission */
>> -		if (!test_and_set_bit(BIT_TX_SCHEDULED, &tx_ctx-
>>> tx_bitmask))
>> -			schedule_delayed_work(&tx_ctx->tx_work.work, 0);
>> -	}
>> +#ifdef CONFIG_TLS_DEVICE
>> +	if (ctx->tx_conf == TLS_HW)
>> +		rc = tls_device_write_space(sk, ctx);
>> +	else
>> +#endif
>> +		rc = tls_sw_write_space(sk, ctx);
>>
>> -	ctx->sk_write_space(sk);
>> +	if (!rc)
> 
> Why do we need to check 'rc'?
> 
> If it is required, then ' ctx->sk_write_space(sk)' can move to tls_device_write_space()
> since  tls_sw_write_space() always returns '0'.
>

It is not necessary in the software code path due to the delayed work 
that is there. But, we need in the device flow. I'll move it there.


>> +		ctx->sk_write_space(sk);
>>   }
>>
>>   static void tls_ctx_free(struct tls_context *ctx)
>> diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
>> index 1cc830582fa8..4afa67b00aaf 100644
>> --- a/net/tls/tls_sw.c
>> +++ b/net/tls/tls_sw.c
>> @@ -2126,6 +2126,21 @@ static void tx_work_handler(struct work_struct
>> *work)
>>   	release_sock(sk);
>>   }
>>
>> +int tls_sw_write_space(struct sock *sk, struct tls_context *ctx)
>> +{
>> +	struct tls_sw_context_tx *tx_ctx = tls_sw_ctx_tx(ctx);
>> +
>> +	/* Schedule the transmission if tx list is ready */
>> +	if (is_tx_ready(tx_ctx) && !sk->sk_write_pending) {
>> +		/* Schedule the transmission */
>> +		if (!test_and_set_bit(BIT_TX_SCHEDULED,
>> +				      &tx_ctx->tx_bitmask))
>> +			schedule_delayed_work(&tx_ctx->tx_work.work, 0);
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>>   int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx)
>>   {
>>   	struct tls_context *tls_ctx = tls_get_ctx(sk);
>> --
>> 2.12.2
>