rnbd: port block device access to file

Link: https://lore.kernel.org/r/20240123-vfs-bdev-file-v2-10-adbd023e19cc@kernel.org
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>

rnbd-srv: Convert to use bdev_open_by_path()

Convert rnbd-srv to use bdev_open_by_path() and pass the handle
around.

CC: Jack Wang <jinpu.wang@ionos.com>
CC: "Md. Haris Iqbal" <haris.iqbal@ionos.com>
Acked-by: "Md. Haris Iqbal" <haris.iqbal@ionos.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230927093442.25915-6-jack@suse.cz
Signed-off-by: Christian Brauner <brauner@kernel.org>

rnbd-srv: replace sess->open_flags with a "bool readonly"

Stop passing the fmode_t around and just use a simple bool to track if
an export is read-only.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Acked-by: Jack Wang <jinpu.wang@ionos.com>
Link: https://lore.kernel.org/r/20230608110258.189493-24-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/rnbd-srv: rename one member in rnbd_srv_dev

It actually represents the name of rnbd_srv_dev.

Acked-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Link: https://lore.kernel.org/r/20230524070026.2932-6-guoqing.jiang@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>

rnbd-srv: remove struct rnbd_dev

Given that rnbd_srv_sess_dev already has an open_flags member, there
is no need for the rnbd_dev indirection as a simple block_device pointer
works just as well.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Acked-by: Jack Wang <jinpu.wang@ionos.com>
Link: https://lore.kernel.org/r/20220909131509.3263924-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/rnbd-srv: Replace sess_dev_list with index_idr

The structure rnbd_srv_session maintains a list and an xarray of
rnbd_srv_dev. There is no need to keep both as one of them can serve the
purpose.

Since one of the places where the lookup of rnbd_srv_dev using
rnbd_srv_session is IO path, an xarray would serve us better than a list
traversal. Hence remove sess_dev_list from rnbd_srv_session, and replace
its uses from xarray.

Signed-off-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Reviewed-by: Aleksei Marov <aleksei.marov@ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Link: https://lore.kernel.org/r/20220707143122.460362-3-haris.iqbal@ionos.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

rnbd-srv: remove the name field from struct rnbd_dev

Just print the block device name directly using the %pg format specifier.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jack Wang <jinpu.wang@ionos.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220713055317.1888500-7-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

rnbd-srv: remove struct rnbd_dev_blk_io

Only the priv field of rnbd_dev_blk_io is used, so store the value of
that in bio->bi_private directly and remove the entire bio_set overhead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jack Wang <jinpu.wang@ionos.com>
Link: https://lore.kernel.org/r/20220124091107.642561-12-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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>

block/rnbd-srv: Remove force_close file after holding a lock

We changed the rnbd_srv_sess_dev_force_close to use try-lock
because rnbd_srv_sess_dev_force_close and process_msg_close
can generate a deadlock.

Now rnbd_srv_sess_dev_force_close would do nothing
if it fails to get the lock. So removing the force_close
file should be moved to after the lock. Or the force_close
file is removed but the others are not removed.

Signed-off-by: Gioh Kim <gi-oh.kim@ionos.com>
Signed-off-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Link: https://lore.kernel.org/r/20210419073722.15351-11-gi-oh.kim@ionos.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/rnbd-srv: close a mapped device from server side.

The forceful close of an exported device is required
for the use case, when the client side hangs, is crashed,
or is not accessible.

There have been cases observed, where only some of
the devices are to be cleaned up, but the session shall
remain.

When the device is to be exported to a different
client host, server side cleanup is required.

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

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

This header describes main structs and functions used by rnbd-server
module, namely structs for managing sessions from different clients and
mapped (opened) devices.

Link: https://lore.kernel.org/r/20200511135131.27580-20-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>