RDMA: Make all 'class' structures const

Now that the driver core allows for struct class to be in read-only
memory, making all 'class' structures to be declared at build time
placing them into read-only memory, instead of having to be dynamically
allocated at load time.

Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Cc: "Md. Haris Iqbal" <haris.iqbal@ionos.com>
Cc: Jack Wang <jinpu.wang@ionos.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Yishai Hadas <yishaih@nvidia.com>
Cc: Ivan Orlov <ivan.orlov0322@gmail.com>
Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/2023080427-commuting-crewless-cbee@gregkh
Signed-off-by: Leon Romanovsky <leon@kernel.org>

RDMA/rtrs: Don't call kobject_del for srv_path->kobj

As the mention in commmit f7452a7e96c1 ("RDMA/rtrs-srv: fix memory leak by missing kobject free"),
it was intended to remove the kobject_del for srv_path->kobj.

f7452a7e96c1 said:
>This patch moves kobject_del() into free_sess() so that the kobject of
> rtrs_srv_sess can be freed.

This patch also move rtrs_srv_destroy_once_sysfs_root_folders back to
'if (srv_path->kobj.state_in_sysfs)' block to avoid a 'held lock freed!'

A kernel panic will be triggered by following script
-----------------------
$ while true
do
echo "sessname=foo path=ip:<ip address> device_path=/dev/nvme0n1" > /sys/devices/virtual/rnbd-client/ctl/map_device
echo "normal" > /sys/block/rnbd0/rnbd/unmap_device
done
-----------------------
The bisection pointed to commit 6af4609c18b3 ("RDMA/rtrs-srv: Fix several issues in rtrs_srv_destroy_path_files")
at last.

rnbd_server L777: </dev/nvme0n1@foo>: Opened device 'nvme0n1'
general protection fault, probably for non-canonical address 0x765f766564753aea: 0000 [#1] PREEMPT SMP PTI
CPU: 0 PID: 3558 Comm: systemd-udevd Kdump: loaded Not tainted 6.1.0-rc3-roce-flush+ #51
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
RIP: 0010:kernfs_dop_revalidate+0x36/0x180
Code: 00 00 41 55 41 54 55 53 48 8b 47 68 48 89 fb 48 85 c0 0f 84 db 00 00 00 48 8b a8 60 04 00 00 48 8b 45 30 48 85 c0 48 0f 44 c5 <4c> 8b 60 78 49 81 c4 d8 00 00 00 4c 89 e7 e8 b7 78 7b 00 8b 05 3d
RSP: 0018:ffffaf1700b67c78 EFLAGS: 00010206
RAX: 765f766564753a72 RBX: ffff89e2830849c0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff89e2830849c0
RBP: ffff89e280361bd0 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000065 R11: 0000000000000000 R12: ffff89e2830849c0
R13: ffff89e283084888 R14: d0d0d0d0d0d0d0d0 R15: 2f2f2f2f2f2f2f2f
FS: 00007f13fbce7b40(0000) GS:ffff89e2bbc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f93e055d340 CR3: 0000000104664002 CR4: 00000000001706f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
lookup_fast+0x7b/0x100
walk_component+0x21/0x160
link_path_walk.part.0+0x24d/0x390
path_openat+0xad/0x9a0
do_filp_open+0xa9/0x150
? lock_release+0x13c/0x2e0
? _raw_spin_unlock+0x29/0x50
? alloc_fd+0x124/0x1f0
do_sys_openat2+0x9b/0x160
__x64_sys_openat+0x54/0xa0
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f13fc9d701b
Code: 25 00 00 41 00 3d 00 00 41 00 74 4b 64 8b 04 25 18 00 00 00 85 c0 75 67 44 89 e2 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 91 00 00 00 48 8b 54 24 28 64 48 2b 14 25
RSP: 002b:00007ffddf242640 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f13fc9d701b
RDX: 0000000000080000 RSI: 00007ffddf2427c0 RDI: 00000000ffffff9c
RBP: 00007ffddf2427c0 R08: 00007f13fcc5b440 R09: 21b2131aa64b1ef2
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000080000
R13: 00007ffddf2427c0 R14: 000055ed13be8db0 R15: 0000000000000000

Fixes: 6af4609c18b3 ("RDMA/rtrs-srv: Fix several issues in rtrs_srv_destroy_path_files")
Acked-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
Link: https://lore.kernel.org/r/1675332721-2-1-git-send-email-lizhijian@fujitsu.com
Acked-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>

RDMA/rtrs-srv: Remove kobject_del from rtrs_srv_destroy_once_sysfs_root_folders

The kobj_paths which is created dynamically by kobject_create_and_add,
and per the comment above kobject_create_and_add, we only need to call
kobject_put which is not same as other kobjs such as stats->kobj_stats
and srv_path->kobj.

Acked-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Link: https://lore.kernel.org/r/20221117101945.6317-9-guoqing.jiang@linux.dev
Signed-off-by: Leon Romanovsky <leon@kernel.org>

RDMA/rtrs-srv: Fix several issues in rtrs_srv_destroy_path_files

There are several issues in the function which is supposed to be paired
with rtrs_srv_create_path_files.

1. rtrs_srv_stats_attr_group is not removed though it is created in
rtrs_srv_create_stats_files.

2. it makes more sense to check kobj_stats.state_in_sysfs before destroy
kobj_stats instead of rely on kobj.state_in_sysfs.

3. kobject_init_and_add is used for both kobjs (srv_path->kobj and
srv_path->stats->kobj_stats), however we missed to call kobject_del
for srv_path->kobj which was called in free_path.

4. rtrs_srv_destroy_once_sysfs_root_folders is independent of either
kobj or kobj_stats.

Acked-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Link: https://lore.kernel.org/r/20221117101945.6317-8-guoqing.jiang@linux.dev
Signed-off-by: Leon Romanovsky <leon@kernel.org>

RDMA/rtrs-srv: Use per-cpu variables for rdma stats

Convert server stat counters from atomic to per-cpu variables.

Link: https://lore.kernel.org/r/20220712103113.617754-4-haris.iqbal@ionos.com
Signed-off-by: Santosh Kumar Pradhan <santosh.pradhan@ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>

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-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>

RDMA/rtrs: Rename rtrs_sess to rtrs_path

rtrs_sess is in fact a path. This makes it confusing and difficult to get
into the code. So let's rename the structure and related use cases of it.

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

Link: https://lore.kernel.org/r/20220105180708.7774-2-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: Use sysfs_emit instead of s*printf function for sysfs show

sysfs_emit function was added to be aware of the PAGE_SIZE maximum of the
temporary buffer used for outputting sysfs content, so there is no
possible overruns. So replace the uses of any s*printf functions for the
sysfs show functions with sysfs_emit.

Link: https://lore.kernel.org/r/20210922125333.351454-2-haris.iqbal@ionos.com
Signed-off-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs-srv: Fix memory leak when having multiple sessions

Gioh notice memory leak below
unreferenced object 0xffff8880acda2000 (size 2048):
comm "kworker/4:1", pid 77, jiffies 4295062871 (age 1270.730s)
hex dump (first 32 bytes):
00 20 da ac 80 88 ff ff 00 20 da ac 80 88 ff ff . ....... ......
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<00000000e85d85b5>] rtrs_srv_rdma_cm_handler+0x8e5/0xa90 [rtrs_server]
[<00000000e31a988a>] cma_ib_req_handler+0xdc5/0x2b50 [rdma_cm]
[<000000000eb02c5b>] cm_process_work+0x2d/0x100 [ib_cm]
[<00000000e1650ca9>] cm_req_handler+0x11bc/0x1c40 [ib_cm]
[<000000009c28818b>] cm_work_handler+0xe65/0x3cf2 [ib_cm]
[<000000002b53eaa1>] process_one_work+0x4bc/0x980
[<00000000da3499fb>] worker_thread+0x78/0x5c0
[<00000000167127a4>] kthread+0x191/0x1e0
[<0000000060802104>] ret_from_fork+0x3a/0x50
unreferenced object 0xffff88806d595d90 (size 8):
comm "kworker/4:1H", pid 131, jiffies 4295062972 (age 1269.720s)
hex dump (first 8 bytes):
62 6c 61 00 6b 6b 6b a5 bla.kkk.
backtrace:
[<000000004447d253>] kstrdup+0x2e/0x60
[<0000000047259793>] kobject_set_name_vargs+0x2f/0xb0
[<00000000c2ee3bc8>] dev_set_name+0xab/0xe0
[<000000002b6bdfb1>] rtrs_srv_create_sess_files+0x260/0x290 [rtrs_server]
[<0000000075d87bd7>] rtrs_srv_info_req_done+0x71b/0x960 [rtrs_server]
[<00000000ccdf1bb5>] __ib_process_cq+0x94/0x100 [ib_core]
[<00000000cbcb60cb>] ib_cq_poll_work+0x32/0xc0 [ib_core]
[<000000002b53eaa1>] process_one_work+0x4bc/0x980
[<00000000da3499fb>] worker_thread+0x78/0x5c0
[<00000000167127a4>] kthread+0x191/0x1e0
[<0000000060802104>] ret_from_fork+0x3a/0x50
unreferenced object 0xffff88806d6bb100 (size 256):
comm "kworker/4:1H", pid 131, jiffies 4295062972 (age 1269.720s)
hex dump (first 32 bytes):
00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00 .....N..........
ff ff ff ff ff ff ff ff 00 59 4d 86 ff ff ff ff .........YM.....
backtrace:
[<00000000a18a11e4>] device_add+0x74d/0xa00
[<00000000a915b95f>] rtrs_srv_create_sess_files.cold+0x49/0x1fe [rtrs_server]
[<0000000075d87bd7>] rtrs_srv_info_req_done+0x71b/0x960 [rtrs_server]
[<00000000ccdf1bb5>] __ib_process_cq+0x94/0x100 [ib_core]
[<00000000cbcb60cb>] ib_cq_poll_work+0x32/0xc0 [ib_core]
[<000000002b53eaa1>] process_one_work+0x4bc/0x980
[<00000000da3499fb>] worker_thread+0x78/0x5c0
[<00000000167127a4>] kthread+0x191/0x1e0
[<0000000060802104>] ret_from_fork+0x3a/0x50

The problem is we increase device refcount by get_device in process_info_req
for each path, but only does put_deice for last path, which lead to
memory leak.

To fix it, it also calls put_device when dev_ref is not 0.

Fixes: e2853c49477d1 ("RDMA/rtrs-srv-sysfs: fix missing put_device")
Link: https://lore.kernel.org/r/20210528113018.52290-19-jinpu.wang@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: 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: Kill the put label in rtrs_srv_create_once_sysfs_root_folders

We can remove the label after move put_device to the right place.

Link: https://lore.kernel.org/r/20210325153308.1214057-9-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>

RDMA/rtrs-srv-sysfs: fix missing put_device

put_device() decreases the ref-count and then the device will be
cleaned-up, while at is also add missing put_device in
rtrs_srv_create_once_sysfs_root_folders

This patch solves a kmemleak error as below:

unreferenced object 0xffff88809a7a0710 (size 8):
comm "kworker/4:1H", pid 113, jiffies 4295833049 (age 6212.380s)
hex dump (first 8 bytes):
62 6c 61 00 6b 6b 6b a5 bla.kkk.
backtrace:
[<0000000054413611>] kstrdup+0x2e/0x60
[<0000000078e3120a>] kobject_set_name_vargs+0x2f/0xb0
[<00000000f1a17a6b>] dev_set_name+0xab/0xe0
[<00000000d5502e32>] rtrs_srv_create_sess_files+0x2fb/0x314 [rtrs_server]
[<00000000ed11a1ef>] rtrs_srv_info_req_done+0x631/0x800 [rtrs_server]
[<000000008fc5aa8f>] __ib_process_cq+0x94/0x100 [ib_core]
[<00000000a9599cb4>] ib_cq_poll_work+0x32/0xc0 [ib_core]
[<00000000cfc376be>] process_one_work+0x4bc/0x980
[<0000000016e5c96a>] worker_thread+0x78/0x5c0
[<00000000c20b8be0>] kthread+0x191/0x1e0
[<000000006c9c0003>] ret_from_fork+0x3a/0x50

Fixes: baa5b28b7a47 ("RDMA/rtrs-srv: Replace device_register with device_initialize and device_add")
Link: https://lore.kernel.org/r/20210212134525.103456-5-jinpu.wang@cloud.ionos.com
Signed-off-by: Gioh Kim <gi-oh.kim@cloud.ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs-srv: fix memory leak by missing kobject free

kmemleak reported an error as below:

unreferenced object 0xffff8880674b7640 (size 64):
comm "kworker/4:1H", pid 113, jiffies 4296403507 (age 507.840s)
hex dump (first 32 bytes):
69 70 3a 31 39 32 2e 31 36 38 2e 31 32 32 2e 31 ip:192.168.122.1
31 30 40 69 70 3a 31 39 32 2e 31 36 38 2e 31 32 10@ip:192.168.12
backtrace:
[<0000000054413611>] kstrdup+0x2e/0x60
[<0000000078e3120a>] kobject_set_name_vargs+0x2f/0xb0
[<00000000ca2be3ee>] kobject_init_and_add+0xb0/0x120
[<0000000062ba5e78>] rtrs_srv_create_sess_files+0x14c/0x314 [rtrs_server]
[<00000000b45b7217>] rtrs_srv_info_req_done+0x5b1/0x800 [rtrs_server]
[<000000008fc5aa8f>] __ib_process_cq+0x94/0x100 [ib_core]
[<00000000a9599cb4>] ib_cq_poll_work+0x32/0xc0 [ib_core]
[<00000000cfc376be>] process_one_work+0x4bc/0x980
[<0000000016e5c96a>] worker_thread+0x78/0x5c0
[<00000000c20b8be0>] kthread+0x191/0x1e0
[<000000006c9c0003>] ret_from_fork+0x3a/0x50

It is caused by the not-freed kobject of rtrs_srv_sess. The kobject
embedded in rtrs_srv_sess has ref-counter 2 after calling
process_info_req(). Therefore it must call kobject_put twice. Currently
it calls kobject_put only once at rtrs_srv_destroy_sess_files because
kobject_del removes the state_in_sysfs flag and then kobject_put in
free_sess() is not called.

This patch moves kobject_del() into free_sess() so that the kobject of
rtrs_srv_sess can be freed. And also this patch adds the missing call of
sysfs_remove_group() to clean-up the sysfs directory.

Fixes: 9cb837480424 ("RDMA/rtrs: server: main functionality")
Link: https://lore.kernel.org/r/20210212134525.103456-4-jinpu.wang@cloud.ionos.com
Signed-off-by: Gioh Kim <gi-oh.kim@cloud.ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs: Call kobject_put in the failure path

Per the comment of kobject_init_and_add, we need to free the memory
by call kobject_put.

Fixes: 215378b838df ("RDMA/rtrs: client: sysfs interface functions")
Fixes: 91b11610af8d ("RDMA/rtrs: server: sysfs interface functions")
Link: https://lore.kernel.org/r/20201217141915.56989-8-jinpu.wang@cloud.ionos.com
Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Reviewed-by: Md Haris Iqbal <haris.iqbal@cloud.ionos.com>
Reviewed-by: Gioh Kim <gi-oh.kim@cloud.ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs-srv: Use sysfs_remove_file_self for disconnect

Remove self first to avoid deadlock, we don't want to
use close_work to remove sess sysfs.

Fixes: 91b11610af8d ("RDMA/rtrs: server: sysfs interface functions")
Link: https://lore.kernel.org/r/20201217141915.56989-5-jinpu.wang@cloud.ionos.com
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Tested-by: Lutz Pogrell <lutz.pogrell@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA: Convert various random sprintf sysfs _show uses to sysfs_emit

Manual changes for sysfs_emit as cocci scripts can't easily convert them.

Link: https://lore.kernel.org/r/ecde7791467cddb570c6f6d2c908ffbab9145cac.1602122880.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA: Convert sysfs kobject * show functions to use sysfs_emit()

Done with cocci script:

@@
identifier k_show;
identifier arg1, arg2, arg3;
@@
ssize_t k_show(struct kobject *
- arg1
+ kobj
, struct kobj_attribute *
- arg2
+ attr
, char *
- arg3
+ buf
)
{
...
(
- arg1
+ kobj
|
- arg2
+ attr
|
- arg3
+ buf
)
...
}

@@
identifier k_show;
identifier kobj, attr, buf;
@@

ssize_t k_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
{
<...
return
- sprintf(buf,
+ sysfs_emit(buf,
...);
...>
}

@@
identifier k_show;
identifier kobj, attr, buf;
@@

ssize_t k_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
{
<...
return
- snprintf(buf, PAGE_SIZE,
+ sysfs_emit(buf,
...);
...>
}

@@
identifier k_show;
identifier kobj, attr, buf;
@@

ssize_t k_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
{
<...
return
- scnprintf(buf, PAGE_SIZE,
+ sysfs_emit(buf,
...);
...>
}

@@
identifier k_show;
identifier kobj, attr, buf;
expression chr;
@@

ssize_t k_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
{
<...
return
- strcpy(buf, chr);
+ sysfs_emit(buf, chr);
...>
}

@@
identifier k_show;
identifier kobj, attr, buf;
identifier len;
@@

ssize_t k_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
{
<...
len =
- sprintf(buf,
+ sysfs_emit(buf,
...);
...>
return len;
}

@@
identifier k_show;
identifier kobj, attr, buf;
identifier len;
@@

ssize_t k_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
{
<...
len =
- snprintf(buf, PAGE_SIZE,
+ sysfs_emit(buf,
...);
...>
return len;
}

@@
identifier k_show;
identifier kobj, attr, buf;
identifier len;
@@

ssize_t k_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
{
<...
len =
- scnprintf(buf, PAGE_SIZE,
+ sysfs_emit(buf,
...);
...>
return len;
}

@@
identifier k_show;
identifier kobj, attr, buf;
identifier len;
@@

ssize_t k_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
{
<...
- len += scnprintf(buf + len, PAGE_SIZE - len,
+ len += sysfs_emit_at(buf, len,
...);
...>
return len;
}

@@
identifier k_show;
identifier kobj, attr, buf;
expression chr;
@@

ssize_t k_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
{
...
- strcpy(buf, chr);
- return strlen(buf);
+ return sysfs_emit(buf, chr);
}

Link: https://lore.kernel.org/r/7761c1efaebb96c432c85171d58405c25a824ccd.1602122880.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs: Constify static struct attribute_group

The only usage of these is to pass their address to sysfs_create_group()
and sysfs_remove_group(), both which takes const pointers. Make it const
to allow the compiler to put them in read-only memory.

Link: https://lore.kernel.org/r/20200930224004.24279-3-rikard.falkeborn@gmail.com
Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs-srv: Set .release function for rtrs srv device during device init

The device .release function was not being set during the device
initialization. This was leading to the below warning, in error cases when
put_srv was called before device_add was called.

Warning:

Device '(null)' does not have a release() function, it is broken and must
be fixed. See Documentation/kobject.txt.

So, set the device .release function during device initialization in the
__alloc_srv() function.

Fixes: baa5b28b7a47 ("RDMA/rtrs-srv: Replace device_register with device_initialize and device_add")
Link: https://lore.kernel.org/r/20200907102216.104041-1-haris.iqbal@cloud.ionos.com
Signed-off-by: Md Haris Iqbal <haris.iqbal@cloud.ionos.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Acked-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs-srv: Replace device_register with device_initialize and device_add

There are error cases when we will call free_srv before device kobject is
initialized; in such cases calling put_device generates the following
warning:

kobject: '(null)' (000000009f5445ed): is not initialized, yet
kobject_put() is being called.

So call device_initialize() only once when the server is allocated. If we
end up calling put_srv() and subsequently free_srv(), our call to
put_device() would result in deletion of the obj. Call device_add() later
when we actually have a connection. Correspondingly, call device_del()
instead of device_unregister() when srv->dev_ref falls to 0.

Fixes: 9cb837480424 ("RDMA/rtrs: server: main functionality")
Link: https://lore.kernel.org/r/20200811092722.2450-1-haris.iqbal@cloud.ionos.com
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Md Haris Iqbal <haris.iqbal@cloud.ionos.com>
Reviewed-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs: server: Fix some error return code

Fix to return negative error code -ENOMEM from the some error handling
cases instead of 0, as done elsewhere in this function.

Fixes: 9cb837480424 ("RDMA/rtrs: server: main functionality")
Fixes: 91b11610af8d ("RDMA/rtrs: server: sysfs interface functions")
Link: https://lore.kernel.org/r/20200519091912.134358-1-weiyongjun1@huawei.com
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: Danil Kipnis <danil.kipnis@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

RDMA/rtrs: server: sysfs interface functions

This is the sysfs interface to rtrs sessions on server side:

/sys/class/rtrs-server/<SESS-NAME>/
*** rtrs session accepted from a client peer
|
|- paths/<SRC@DST>/
*** established paths from a client in a session
|
|- disconnect
| *** disconnect path
|
|- hca_name
| *** HCA name
|
|- hca_port
| *** HCA port
|
|- stats/
*** current path statistics
|
|- rdma

Link: https://lore.kernel.org/r/20200511135131.27580-13-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>