rnbd-clt: pass sector_t type for resize capacity

Let's change the parameter type to 'sector_t' then we don't need to cast
it from rnbd_clt_resize_dev_store, and update rnbd_clt_resize_disk too.

Acked-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Link: https://lore.kernel.org/r/20220706133152.12058-8-guoqing.jiang@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>

rnbd-clt: adjust the layout of struct rnbd_clt_dev

While at it, let re-arrange the struct to remove holes.

Before, pahole reports

/* size: 232, cachelines: 4, members: 17 */
/* sum members: 224, holes: 2, sum holes: 8 */
/* last cacheline: 40 bytes */

After the change, the report changes to

/* size: 224, cachelines: 4, members: 17 */
/* last cacheline: 32 bytes */

Acked-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Link: https://lore.kernel.org/r/20220706133152.12058-6-guoqing.jiang@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>

rnbd-clt: reduce the size of struct rnbd_clt_dev

Previously, both map and remap trigger rnbd_clt_set_dev_attr to set
some members in rnbd_clt_dev such as wc, fua and logical_block_size
etc, but those members are only useful for map scenario given the
setup_request_queue is only called from the path:

rnbd_clt_map_device -> rnbd_client_setup_device

Since rnbd_clt_map_device frees rsp after rnbd_client_setup_device,
we can pass rsp to rnbd_client_setup_device and it's callees, which
means queue's attributes can be set directly from relevant members
of rsp instead from rnbd_clt_dev.

After that, we can kill 11 members from rnbd_clt_dev, and we don't
need rnbd_clt_set_dev_attr either.

Acked-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Link: https://lore.kernel.org/r/20220706133152.12058-5-guoqing.jiang@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>

rnbd-clt: kill read_only from struct rnbd_clt_dev

The member is not needed since we can call get_disk_ro to achieve the
same goal.

Acked-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Link: https://lore.kernel.org/r/20220706133152.12058-4-guoqing.jiang@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>

scsi: rnbd: Remove WRITE_SAME support

REQ_OP_WRITE_SAME was only ever submitted by the legacy Linux zeroing code,
which has switched to use REQ_OP_WRITE_ZEROES long before rnbd was even
merged.

Link: https://lore.kernel.org/r/20220209082828.2629273-4-hch@lst.de
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Acked-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

block/rnbd: client device does not care queue/rotational

On client side, the device is a network device. There is no reason
to set rotational even-if the target device on server is rotational.

Signed-off-by: Gioh Kim <gi-oh.kim@ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Link: https://lore.kernel.org/r/20220114155855.984144-3-haris.iqbal@ionos.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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>

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>

block/rnbd-clt: Change queue_depth type in rnbd_clt_session to size_t

The member queue_depth in the structure rnbd_clt_session is read from the
rtrs client side using the function rtrs_clt_query, which in turn is read
from the rtrs_clt structure. It should really be of type size_t.

Fixes: 90426e89f54db ("block/rnbd: client: private header with client structs and functions")
Signed-off-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Reviewed-by: Guoqing Jiang <guoqing.jiang@ionos.com>
Signed-off-by: Gioh Kim <gi-oh.kim@ionos.com>
Link: https://lore.kernel.org/r/20210428061359.206794-2-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: Kill rnbd_clt_destroy_default_group

No need to have it since we can call sysfs_remove_group in the
rnbd_clt_destroy_sysfs_files.

Then rnbd_clt_destroy_sysfs_files is paired with it's counterpart
rnbd_clt_create_sysfs_files.

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>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Link: https://lore.kernel.org/r/20210419073722.15351-7-gi-oh.kim@ionos.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/rnbd-clt: Dynamically allocate sglist for rnbd_iu

The BMAX_SEGMENT static array for scatterlist is embedded in
rnbd_iu structure to avoid memory allocation in hot IO path.
In many cases, we do need only several sg entries because many IOs
have only several segments.

This patch change rnbd_iu to check the number of segments in the request
and allocate sglist dynamically.

For io path, use sg_alloc_table_chained to allocate sg list faster.

First it makes two sg entries after pdu of request.
The sg_alloc_table_chained uses the pre-allocated sg entries
if the number of segments of the request is less than two.
So it reduces the number of memory allocation.

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>

block/rnbd: Set write-back cache and fua same to the target device

The rnbd-client always sets the write-back cache and fua attributes
of the rnbd device queue regardless of the target device on the server.
That generates IO hang issue when the target device does not
support both of write-back cacne and fua.

This patch adds more fields for the cache policy and fua into the
device opening message. The rnbd-server sends the information
if the target device supports the write-back cache and fua
and rnbd-client recevives it and set the device queue accordingly.

Signed-off-by: Gioh Kim <gi-oh.kim@cloud.ionos.com>
[jwang: some minor change, rename a few varables, remove unrelated comments.]
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/rnbd-clt: Dynamically alloc buffer for pathname & blk_symlink_name

For every rnbd_clt_dev, we alloc the pathname and blk_symlink_name
statically to NAME_MAX which is 255 bytes. In most of the cases we only
need less than 10 bytes, so 500 bytes per block device are wasted.

This commit dynamically allocates memory buffer for pathname and
blk_symlink_name.

Signed-off-by: Md Haris Iqbal <haris.iqbal@cloud.ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Reviewed-by: Lutz Pogrell <lutz.pogrell@cloud.ionos.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/rnbd: client: private header with client structs and functions

This header describes main structs and functions used by rnbd-client
module, mainly for managing RNBD sessions and mapped block devices,
creating and destroying sysfs entries.

Link: https://lore.kernel.org/r/20200511135131.27580-17-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>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>