RDMA/rtrs: Remove 'dir' argument from rnbd_srv_rdma_ev

Since process_{read,write} already prints direction info if ctx->ops.rdma_ev
fails, no need to pass 'dir'.

Link: https://lore.kernel.org/r/20220826081117.21687-1-guoqing.jiang@linux.dev
Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Signed-off-by: Leon Romanovsky <leon@kernel.org>

RDMA/rtrs-clt: Rename rtrs_clt to rtrs_clt_sess

Structure rtrs_clt is used for sessions. So to avoid confusions rename it
to rtrs_clt_sess.

Transformations are done with the help of following coccinelle script.

@@
@@
struct
- rtrs_clt
+ rtrs_clt_sess

Link: https://lore.kernel.org/r/20220105180708.7774-6-jinpu.wang@ionos.com
Signed-off-by: Vaishali Thakkar <vaishali.thakkar@ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs-srv: Rename rtrs_srv to rtrs_srv_sess

Structure rtrs_srv is used for sessions so in order to avoid confusions
rename it to rtrs_srv_sess.

All changes were done with the help of following Coccinelle script:

@@
@@
struct
- rtrs_srv
+ rtrs_srv_sess

Link: https://lore.kernel.org/r/20220105180708.7774-5-jinpu.wang@ionos.com
Signed-off-by: Vaishali Thakkar <vaishali.thakkar@ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs-clt: Rename rtrs_clt_sess to rtrs_clt_path

rtrs_clt_sess is used for paths and not sessions on the client side. This
creates confusion so let's rename it to rtrs_clt_path. Also, rename
related variables and functions.

Coccinelle is used to do the transformations for most of the occurrences
and remaining ones were handled manually.

Link: https://lore.kernel.org/r/20220105180708.7774-4-jinpu.wang@ionos.com
Signed-off-by: Vaishali Thakkar <vaishali.thakkar@ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs-srv: Rename rtrs_srv_sess to rtrs_srv_path

rtrs_srv_sess is used for paths and not sessions on the server side. This
creates confusion so let's rename it to rtrs_srv_path. Also, rename
related variables and functions.

Coccinelle is used to do the transformations for most of the occurrences
and remaining ones were handled manually.

Link: https://lore.kernel.org/r/20220105180708.7774-3-jinpu.wang@ionos.com
Signed-off-by: Vaishali Thakkar <vaishali.thakkar@ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

rnbd/rtrs-clt: Query and use max_segments from rtrs-clt.

With fast memory registration on write request, rnbd-clt
can do bigger IO without split. rnbd-clt now can query
rtrs-clt to get the max_segments, instead of using
BMAX_SEGMENTS.

BMAX_SEGMENTS is not longer needed, so remove it.

Link: https://lore.kernel.org/r/20210621055340.11789-6-jinpu.wang@ionos.com
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Reviewed-by: Md Haris Iqbal <haris.iqbal@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs: New function converting rtrs_addr to string

There is common code converting addresses of source machine and
destination machine to a string. We already have a struct rtrs_addr to
store two addresses. This patch introduces a new function that converts
two addresses into one string with struct rtrs_addr.

Link: https://lore.kernel.org/r/20210325153308.1214057-14-gi-oh.kim@ionos.com
Signed-off-by: Gioh Kim <gi-oh.kim@ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs: Remove sessname and sess_kobj from rtrs_attrs

The two members are not used in the code, so remove them.

Link: https://lore.kernel.org/r/20210325153308.1214057-10-gi-oh.kim@ionos.com
Signed-off-by: Guoqing Jiang <guoqing.jiang@ionos.com>
Reviewed-by: Danil Kipnis <danil.kipnis@ionos.com>
Signed-off-by: Gioh Kim <gi-oh.kim@ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

block/rnbd-clt: Remove max_segment_size

We always map with SZ_4K, so do not need max_segment_size.

Cc: Leon Romanovsky <leonro@nvidia.com>
Cc: linux-rdma@vger.kernel.org
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Reviewed-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Signed-off-by: Gioh Kim <gi-oh.kim@ionos.com>
Acked-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Link: https://lore.kernel.org/r/20210419073722.15351-18-gi-oh.kim@ionos.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/rnbd-srv: Remove unused arguments of rnbd_srv_rdma_ev

struct rtrs_srv is not used when handling rnbd_srv_rdma_ev messages, so
cleaned up
rdma_ev function pointer in rtrs_srv_ops also is changed.

Cc: Leon Romanovsky <leonro@nvidia.com>
Cc: linux-rdma@vger.kernel.org
Signed-off-by: Aleksei Marov <aleksei.marov@ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Gioh Kim <gi-oh.kim@ionos.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Acked-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Link: https://lore.kernel.org/r/20210419073722.15351-16-gi-oh.kim@ionos.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/rnbd-clt: Support polling mode for IO latency optimization

RNBD can make double-queues for irq-mode and poll-mode.
For example, on 4-CPU system 8 request-queues are created,
4 for irq-mode and 4 for poll-mode.
If the IO has HIPRI flag, the block-layer will call .poll function
of RNBD. Then IO is sent to the poll-mode queue.
Add optional nr_poll_queues argument for map_devices interface.

To support polling of RNBD, RTRS client creates connections
for both of irq-mode and direct-poll-mode.

For example, on 4-CPU system it could've create 5 connections:
con[0] => user message (softirq cq)
con[1:4] => softirq cq

After this patch, it can create 9 connections:
con[0] => user message (softirq cq)
con[1:4] => softirq cq
con[5:8] => DIRECT-POLL cq

Cc: Leon Romanovsky <leonro@nvidia.com>
Cc: linux-rdma@vger.kernel.org
Signed-off-by: Gioh Kim <gi-oh.kim@ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Acked-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Link: https://lore.kernel.org/r/20210419073722.15351-14-gi-oh.kim@ionos.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/rnbd-clt: Replace {NO_WAIT,WAIT} with RTRS_PERMIT_{WAIT,NOWAIT}

They are defined with the same value and similar meaning, let's remove
one of them, then we can remove {WAIT,NOWAIT}.

Also change the type of 'wait' from 'int' to 'enum wait_type' to make
it clear.

Cc: Leon Romanovsky <leonro@nvidia.com>
Cc: linux-rdma@vger.kernel.org
Signed-off-by: Guoqing Jiang <guoqing.jiang@ionos.com>
Reviewed-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Signed-off-by: Gioh Kim <gi-oh.kim@ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Acked-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Link: https://lore.kernel.org/r/20210419073722.15351-9-gi-oh.kim@ionos.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/rnbd-clt: Does not request pdu to rtrs-clt

Previously the rnbd client requested the rtrs to allocate rnbd_iu
just after the rtrs_iu. So the rnbd client passes the size of
rnbd_iu for rtrs_clt_open() and rtrs creates an array of
rnbd_iu and rtrs_iu.

For IO handling, rnbd_iu exists after the request because we pass
the size of rnbd_iu when setting the tag-set. Therefore we do not
use the rnbd_iu allocated by rtrs for IO handling.
We only use the rnbd_iu allocated by rtrs when doing session
initialization. Almost all rnbd_iu allocated by rtrs are wasted.

By this patch the rnbd client does not request rnbd_iu allocation
to rtrs but allocate it for itself when doing session initialization.

Also remove unused rtrs_permit_to_pdu from rtrs.

Signed-off-by: Gioh Kim <gi-oh.kim@cloud.ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

rnbd/rtrs: Pass max segment size from blk user to the rdma library

When Block Device Layer is disabled, BLK_MAX_SEGMENT_SIZE is undefined.
The rtrs is a transport library and should compile independently of the
block layer. The desired max segment size should be passed down by the
user.

Introduce max_segment_size parameter for the rtrs_clt_open() call.

Fixes: f7a7a5c228d4 ("block/rnbd: client: main functionality")
Fixes: 6a98d71daea1 ("RDMA/rtrs: client: main functionality")
Fixes: cb80329c9434 ("RDMA/rtrs: client: private header with client structs and functions")
Fixes: b5c27cdb094e ("RDMA/rtrs: public interface header to establish RDMA connections")
Link: https://lore.kernel.org/r/20200519111419.924170-1-danil.kipnis@cloud.ionos.com
Signed-off-by: Danil Kipnis <danil.kipnis@cloud.ionos.com>
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

RDMA/rtrs: public interface header to establish RDMA connections

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.

Link: https://lore.kernel.org/r/20200511135131.27580-3-danil.kipnis@cloud.ionos.com
Signed-off-by: Danil Kipnis <danil.kipnis@cloud.ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>