On Tue, Mar 3, 2020 at 10:40 AM Leon Romanovsky <leon@xxxxxxxxxx> wrote:
>
> On Fri, Feb 21, 2020 at 11:46:58AM +0100, Jack Wang wrote:
> > From: Jack Wang <jinpu.wang@xxxxxxxxxxxxxxx>
> >
> > Introduce public header which provides set of API functions to
> > establish RDMA connections from client to server machine using
> > RTRS protocol, which manages RDMA connections for each session,
> > does multipathing and load balancing.
> >
> > Main functions for client (active) side:
> >
> > rtrs_clt_open() - Creates set of RDMA connections incapsulated
> > in IBTRS session and returns pointer on RTRS
> > session object.
> > rtrs_clt_close() - Closes RDMA connections associated with RTRS
> > session.
> > rtrs_clt_request() - Requests zero-copy RDMA transfer to/from
> > server.
> >
> > Main functions for server (passive) side:
> >
> > rtrs_srv_open() - Starts listening for RTRS clients on specified
> > port and invokes RTRS callbacks for incoming
> > RDMA requests or link events.
> > rtrs_srv_close() - Closes RTRS server context.
> >
> > Signed-off-by: Danil Kipnis <danil.kipnis@xxxxxxxxxxxxxxx>
> > Signed-off-by: Jack Wang <jinpu.wang@xxxxxxxxxxxxxxx>
> > ---
> > drivers/infiniband/ulp/rtrs/rtrs.h | 310 +++++++++++++++++++++++++++++
> > 1 file changed, 310 insertions(+)
> > create mode 100644 drivers/infiniband/ulp/rtrs/rtrs.h
> >
> > diff --git a/drivers/infiniband/ulp/rtrs/rtrs.h b/drivers/infiniband/ulp/rtrs/rtrs.h
> > new file mode 100644
> > index 000000000000..5e1c8a654e92
> > --- /dev/null
> > +++ b/drivers/infiniband/ulp/rtrs/rtrs.h
> > @@ -0,0 +1,310 @@
> > +/* SPDX-License-Identifier: GPL-2.0-or-later */
> > +/*
> > + * RDMA Transport Layer
> > + *
> > + * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
> > + * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
> > + * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
> > + */
> > +#ifndef RTRS_H
> > +#define RTRS_H
> > +
> > +#include <linux/socket.h>
> > +#include <linux/scatterlist.h>
> > +
> > +struct rtrs_permit;
> > +struct rtrs_clt;
> > +struct rtrs_srv_ctx;
> > +struct rtrs_srv;
> > +struct rtrs_srv_op;
> > +
> > +/*
> > + * RDMA transport (RTRS) client API
> > + */
> > +
> > +/**
> > + * enum rtrs_clt_link_ev - Events about connectivity state of a client
> > + * @RTRS_CLT_LINK_EV_RECONNECTED Client was reconnected.
> > + * @RTRS_CLT_LINK_EV_DISCONNECTED Client was disconnected.
> > + */
> > +enum rtrs_clt_link_ev {
> > + RTRS_CLT_LINK_EV_RECONNECTED,
> > + RTRS_CLT_LINK_EV_DISCONNECTED,
> > +};
> > +
> > +/**
> > + * Source and destination address of a path to be established
> > + */
> > +struct rtrs_addr {
> > + struct sockaddr_storage *src;
> > + struct sockaddr_storage *dst;
> > +};
> > +
> > +typedef void (link_clt_ev_fn)(void *priv, enum rtrs_clt_link_ev ev);
> > +/**
> > + * rtrs_clt_open() - Open a session to an RTRS server
> > + * @priv: User supplied private data.
> > + * @link_ev: Event notification callback function for connection state changes
> > + * @priv: User supplied data that was passed to rtrs_clt_open()
> > + * @ev: Occurred event
> > + * @sessname: name of the session
> > + * @paths: Paths to be established defined by their src and dst addresses
> > + * @path_cnt: Number of elements in the @paths array
> > + * @port: port to be used by the RTRS session
> > + * @pdu_sz: Size of extra payload which can be accessed after permit allocation.
> > + * @max_inflight_msg: Max. number of parallel inflight messages for the session
> > + * @max_segments: Max. number of segments per IO request
> > + * @reconnect_delay_sec: time between reconnect tries
> > + * @max_reconnect_attempts: Number of times to reconnect on error before giving
> > + * up, 0 for * disabled, -1 for forever
> > + *
> > + * Starts session establishment with the rtrs_server. The function can block
> > + * up to ~2000ms before it returns.
> > + *
> > + * Return a valid pointer on success otherwise PTR_ERR.
> > + */
> > +struct rtrs_clt *rtrs_clt_open(void *priv, link_clt_ev_fn *link_ev,
> > + const char *sessname,
> > + const struct rtrs_addr *paths,
> > + size_t path_cnt, u16 port,
> > + size_t pdu_sz, u8 reconnect_delay_sec,
> > + u16 max_segments,
> > + s16 max_reconnect_attempts);
> > +
> > +/**
> > + * rtrs_clt_close() - Close a session
> > + * @sess: Session handle. Session is freed upon return.
> > + */
> > +void rtrs_clt_close(struct rtrs_clt *sess);
> > +
> > +/**
> > + * rtrs_permit_to_pdu() - converts rtrs_permit to opaque pdu pointer
> > + * @permit: RTRS permit pointer, it associates the memory allocation for future
> > + * RDMA operation.
> > + */
> > +void *rtrs_permit_to_pdu(struct rtrs_permit *permit);
> > +
> > +enum {
> > + RTRS_PERMIT_NOWAIT = 0,
> > + RTRS_PERMIT_WAIT = 1,
> > +};
> > +
> > +/**
> > + * enum rtrs_clt_con_type() type of ib connection to use with a given
> > + * rtrs_permit
> > + * @USR_CON - use connection reserved vor "service" messages
> > + * @IO_CON - use a connection reserved for IO
> > + */
> > +enum rtrs_clt_con_type {
> > + RTRS_USR_CON,
> > + RTRS_IO_CON
> > +};
> > +
> > +/**
> > + * rtrs_clt_get_permit() - allocates permit for future RDMA operation
> > + * @sess: Current session
> > + * @con_type: Type of connection to use with the permit
> > + * @wait: Wait type
> > + *
> > + * Description:
> > + * Allocates permit for the following RDMA operation. Permit is used
> > + * to preallocate all resources and to propagate memory pressure
> > + * up earlier.
> > + *
> > + * Context:
> > + * Can sleep if @wait == RTRS_TAG_WAIT
> > + */
> > +struct rtrs_permit *rtrs_clt_get_permit(struct rtrs_clt *sess,
> > + enum rtrs_clt_con_type con_type,
> > + int wait);
> > +
> > +/**
> > + * rtrs_clt_put_permit() - puts allocated permit
> > + * @sess: Current session
> > + * @permit: Permit to be freed
> > + *
> > + * Context:
> > + * Does not matter
> > + */
> > +void rtrs_clt_put_permit(struct rtrs_clt *sess, struct rtrs_permit *permit);
> > +
> > +typedef void (rtrs_conf_fn)(void *priv, int errno);
> > +/**
> > + * rtrs_clt_request() - Request data transfer to/from server via RDMA.
> > + *
> > + * @dir: READ/WRITE
> > + * @conf: callback function to be called as confirmation
> > + * @sess: Session
> > + * @permit: Preallocated permit
> > + * @priv: User provided data, passed back with corresponding
> > + * @(conf) confirmation.
> > + * @vec: Message that is sent to server together with the request.
> > + * Sum of len of all @vec elements limited to <= IO_MSG_SIZE.
> > + * Since the msg is copied internally it can be allocated on stack.
> > + * @nr: Number of elements in @vec.
> > + * @len: length of data sent to/from server
> > + * @sg: Pages to be sent/received to/from server.
> > + * @sg_cnt: Number of elements in the @sg
> > + *
> > + * Return:
> > + * 0: Success
> > + * <0: Error
> > + *
> > + * On dir=READ rtrs client will request a data transfer from Server to client.
> > + * The data that the server will respond with will be stored in @sg when
> > + * the user receives an %RTRS_CLT_RDMA_EV_RDMA_REQUEST_WRITE_COMPL event.
> > + * On dir=WRITE rtrs client will rdma write data in sg to server side.
> > + */
> > +int rtrs_clt_request(int dir, rtrs_conf_fn *conf, struct rtrs_clt *sess,
> > + struct rtrs_permit *permit, void *priv,
> > + const struct kvec *vec, size_t nr, size_t len,
> > + struct scatterlist *sg, unsigned int sg_cnt);
> > +
> > +/**
> > + * rtrs_attrs - RTRS session attributes
> > + */
> > +struct rtrs_attrs {
> > + u32 queue_depth;
> > + u32 max_io_size;
> > + u8 sessname[NAME_MAX];
> > + struct kobject *sess_kobj;
> > +};
> > +
> > +/**
> > + * rtrs_clt_query() - queries RTRS session attributes
> > + *
> > + * Returns:
> > + * 0 on success
> > + * -ECOMM no connection to the server
> > + */
> > +int rtrs_clt_query(struct rtrs_clt *sess, struct rtrs_attrs *attr);
> > +
> > +/*
> > + * Here goes RTRS server API
> > + */
> > +
> > +/**
> > + * enum rtrs_srv_link_ev - Server link events
> > + * @RTRS_SRV_LINK_EV_CONNECTED: Connection from client established
> > + * @RTRS_SRV_LINK_EV_DISCONNECTED: Connection was disconnected, all
> > + * connection RTRS resources were freed.
> > + */
> > +enum rtrs_srv_link_ev {
> > + RTRS_SRV_LINK_EV_CONNECTED,
> > + RTRS_SRV_LINK_EV_DISCONNECTED,
> > +};
> > +
> > +/**
> > + * rdma_ev_fn(): Event notification for RDMA operations
> > + * If the callback returns a value != 0, an error message
> > + * for the data transfer will be sent to the client.
> > +
> > + * @sess: Session
> > + * @priv: Private data set by rtrs_srv_set_sess_priv()
> > + * @id: internal RTRS operation id
> > + * @dir: READ/WRITE
> > + * @data: Pointer to (bidirectional) rdma memory area:
> > + * - in case of %RTRS_SRV_RDMA_EV_RECV contains
> > + * data sent by the client
> > + * - in case of %RTRS_SRV_RDMA_EV_WRITE_REQ points to the
> > + * memory area where the response is to be written to
> > + * @datalen: Size of the memory area in @data
> > + * @usr: The extra user message sent by the client (%vec)
> > + * @usrlen: Size of the user message
> > + */
> > +typedef int (rdma_ev_fn)(struct rtrs_srv *sess, void *priv,
> > + struct rtrs_srv_op *id, int dir,
> > + void *data, size_t datalen, const void *usr,
> > + size_t usrlen);
> > +
> > +/**
> > + * link_ev_fn(): Events about connectivity state changes
> > + * If the callback returns != 0 and the event
> > + * %RTRS_SRV_LINK_EV_CONNECTED the corresponding session
> > + * will be destroyed.
> > + * @sess: Session
> > + * @ev: event
> > + * @priv: Private data from user if previously set with
> > + * rtrs_srv_set_sess_priv()
> > + */
> > +typedef int (link_ev_fn)(struct rtrs_srv *sess, enum rtrs_srv_link_ev ev,
> > + void *priv);
>
> I don't think that it is good idea to add typedefs to hide function
> callbacks definitions.
>
> Thanks
Hi Leon,
What's the preferred way to do it, could you point me an example?
Thanks!
