[Patch v8 02/16] CIFS: SMBD: Implement function to reconnect to a SMB Direct transport

[Steve French]

various checkpatch errors (remember to run scripts/chekckpatch.pl
before submitting)

On Wed, Nov 22, 2017 at 6:38 PM, Long Li <longli at exchange.microsoft.com> wrote:
> From: Long Li <longli at microsoft.com>
>
> Add function to implement a reconnect to SMB Direct. This involves tearing down
> the current connection and establishing/negotiating a new connection.
>
> Signed-off-by: Long Li <longli at microsoft.com>
> ---
>  fs/cifs/smbdirect.c | 36 ++++++++++++++++++++++++++++++++++++
>  fs/cifs/smbdirect.h |  4 ++++
>  2 files changed, 40 insertions(+)
>
> diff --git a/fs/cifs/smbdirect.c b/fs/cifs/smbdirect.c
> index 862cdf9..a96058a 100644
> --- a/fs/cifs/smbdirect.c
> +++ b/fs/cifs/smbdirect.c
> @@ -1387,6 +1387,42 @@ static void idle_connection_timer(struct work_struct *work)
>                         info->keep_alive_interval*HZ);
>  }
>
> +/*
> + * Reconnect this SMBD connection, called from upper layer
> + * return value: 0 on success, or actual error code
> + */
> +int smbd_reconnect(struct TCP_Server_Info *server)
> +{
> +       log_rdma_event(INFO, "reconnecting rdma session\n");
> +
> +       if (!server->smbd_conn) {
> +               log_rdma_event(ERR, "rdma session already destroyed\n");
> +               return -EINVAL;
> +       }
> +
> +       /*
> +        * This is possible if transport is disconnected and we haven't received
> +        * notification from RDMA, but upper layer has detected timeout
> +        */
> +       if (server->smbd_conn->transport_status == SMBD_CONNECTED) {
> +               log_rdma_event(INFO, "disconnecting transport\n");
> +               smbd_disconnect_rdma_connection(server->smbd_conn);
> +       }
> +
> +       /* wait until the transport is destroyed */
> +       wait_event(server->smbd_conn->wait_destroy,
> +               server->smbd_conn->transport_status == SMBD_DESTROYED);
> +
> +       destroy_workqueue(server->smbd_conn->workqueue);
> +       kfree(server->smbd_conn);
> +
> +       log_rdma_event(INFO, "creating rdma session\n");
> +       server->smbd_conn = smbd_get_connection(
> +               server, (struct sockaddr *) &server->dstaddr);
> +
> +       return server->smbd_conn ? 0 : -ENOENT;
> +}
> +
>  static void destroy_caches_and_workqueue(struct smbd_connection *info)
>  {
>         destroy_receive_buffers(info);
> diff --git a/fs/cifs/smbdirect.h b/fs/cifs/smbdirect.h
> index 25b3782..8948f06 100644
> --- a/fs/cifs/smbdirect.h
> +++ b/fs/cifs/smbdirect.h
> @@ -247,11 +247,15 @@ struct smbd_response {
>  struct smbd_connection *smbd_get_connection(
>         struct TCP_Server_Info *server, struct sockaddr *dstaddr);
>
> +/* Reconnect SMBDirect session */
> +int smbd_reconnect(struct TCP_Server_Info *server);
> +
>  #else
>  #define cifs_rdma_enabled(server)      0
>  struct smbd_connection {};
>  static inline void *smbd_get_connection(
>         struct TCP_Server_Info *server, struct sockaddr *dstaddr) {return NULL;}
> +static inline int smbd_reconnect(struct TCP_Server_Info *server) {return -1;}
>  #endif
>
>  #endif
> --
> 2.7.4
>
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-- 
Thanks,

Steve