net/tls: Replace TLS_RX_SYNC_RUNNING with RCU

RCU synchronization is guaranteed to finish in finite time, unlike a
busy loop that polls a flag. This patch is a preparation for the bugfix
in the next patch, where the same synchronize_net() call will also be
used to sync with the TX datapath.

Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Maxim Mikityanskiy 2021-06-01 15:07:59 +03:00 committed by David S. Miller
parent f336d0b93a
commit 05fc8b6cbd
2 changed files with 3 additions and 8 deletions

View File

@ -193,7 +193,6 @@ struct tls_offload_context_tx {
(sizeof(struct tls_offload_context_tx) + TLS_DRIVER_STATE_SIZE_TX)
enum tls_context_flags {
TLS_RX_SYNC_RUNNING = 0,
/* Unlike RX where resync is driven entirely by the core in TX only
* the driver knows when things went out of sync, so we need the flag
* to be atomic.

View File

@ -680,15 +680,13 @@ static void tls_device_resync_rx(struct tls_context *tls_ctx,
struct tls_offload_context_rx *rx_ctx = tls_offload_ctx_rx(tls_ctx);
struct net_device *netdev;
if (WARN_ON(test_and_set_bit(TLS_RX_SYNC_RUNNING, &tls_ctx->flags)))
return;
trace_tls_device_rx_resync_send(sk, seq, rcd_sn, rx_ctx->resync_type);
rcu_read_lock();
netdev = READ_ONCE(tls_ctx->netdev);
if (netdev)
netdev->tlsdev_ops->tls_dev_resync(netdev, sk, seq, rcd_sn,
TLS_OFFLOAD_CTX_DIR_RX);
clear_bit_unlock(TLS_RX_SYNC_RUNNING, &tls_ctx->flags);
rcu_read_unlock();
TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSRXDEVICERESYNC);
}
@ -1300,9 +1298,7 @@ static int tls_device_down(struct net_device *netdev)
netdev->tlsdev_ops->tls_dev_del(netdev, ctx,
TLS_OFFLOAD_CTX_DIR_RX);
WRITE_ONCE(ctx->netdev, NULL);
smp_mb__before_atomic(); /* pairs with test_and_set_bit() */
while (test_bit(TLS_RX_SYNC_RUNNING, &ctx->flags))
usleep_range(10, 200);
synchronize_net();
dev_put(netdev);
list_del_init(&ctx->list);