RDMA/rtrs-clt: Use %pe to print errors

While printing error, replace %ld by %pe. %pe prints a string
whereas %ld would print an error code.

Signed-off-by: Supriti Singh <supriti.singh@ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Grzegorz Prajsner <grzegorz.prajsner@ionos.com>
Signed-off-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Link: https://lore.kernel.org/r/20231120154146.920486-9-haris.iqbal@ionos.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>

RDMA/rtrs-clt: Add warning logs for RDMA events

Some RDMA CM events can trigger connection close or recovery for a
certain rtrs_clt_path. Such close/recovery triggers should happen after
an appropriate log message, since they can lead to IO failures.

Signed-off-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Grzegorz Prajsner <grzegorz.prajsner@ionos.com>
Link: https://lore.kernel.org/r/20231115152749.424301-2-haris.iqbal@ionos.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>

RDMA/rtrs-clt: Remove the warnings for req in_use check

As we chain the WR during write request: memory registration,
rdma write, local invalidate, if only the last WR fail to send due
to send queue overrun, the server can send back the reply, while
client mark the req->in_use to false in case of error in rtrs_clt_req
when error out from rtrs_post_rdma_write_sg.

Fixes: 6a98d71daea1 ("RDMA/rtrs: client: main functionality")
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Reviewed-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Signed-off-by: Grzegorz Prajsner <grzegorz.prajsner@ionos.com>
Link: https://lore.kernel.org/r/20231120154146.920486-8-haris.iqbal@ionos.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>

RDMA/rtrs-clt: Fix the max_send_wr setting

For each write request, we need Request, Response Memory Registration,
Local Invalidate.

Fixes: 6a98d71daea1 ("RDMA/rtrs: client: main functionality")
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Reviewed-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Signed-off-by: Grzegorz Prajsner <grzegorz.prajsner@ionos.com>
Link: https://lore.kernel.org/r/20231120154146.920486-7-haris.iqbal@ionos.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>

RDMA/rtrs-clt: Start hb after path_up

If we start hb too early, it will confuse server side to close
the session.

Fixes: 6a98d71daea1 ("RDMA/rtrs: client: main functionality")
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Reviewed-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Signed-off-by: Grzegorz Prajsner <grzegorz.prajsner@ionos.com>
Link: https://lore.kernel.org/r/20231120154146.920486-3-haris.iqbal@ionos.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>

RDMA/rtrs: Require holding rcu_read_lock explicitly

No functional change. The function get_next_path_rr needs to hold
rcu_read_lock. As such, if no rcu read lock, warnings will pop out.

Acked-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Zhu Yanjun <yanjun.zhu@linux.dev>
Link: https://lore.kernel.org/r/20230919073727.540207-1-yanjun.zhu@intel.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>

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: Fix rxe_dealloc_pd warning

In current design:
1. PD and clt_path->s.dev are shared among connections.
2. every con[n]'s cleanup phase will call destroy_con_cq_qp()
3. clt_path->s.dev will be always decreased in destroy_con_cq_qp(), and
when clt_path->s.dev become zero, it will destroy PD.
4. when con[1] failed to create, con[1] will not take clt_path->s.dev,
but it try to decreased clt_path->s.dev

So, in case create_cm(con[0]) succeeds but create_cm(con[1]) fails,
destroy_con_cq_qp(con[1]) will be called first which will destroy the PD
while this PD is still taken by con[0].

Here, we refactor the error path of create_cm() and init_conns(), so that
we do the cleanup in the order they are created.

The warning occurs when destroying RXE PD whose reference count is not
zero.

rnbd_client L597: Mapping device /dev/nvme0n1 on session client, (access_mode: rw, nr_poll_queues: 0)
------------[ cut here ]------------
WARNING: CPU: 0 PID: 26407 at drivers/infiniband/sw/rxe/rxe_pool.c:256 __rxe_cleanup+0x13a/0x170 [rdma_rxe]
Modules linked in: rpcrdma rdma_ucm ib_iser rnbd_client libiscsi rtrs_client scsi_transport_iscsi rtrs_core rdma_cm iw_cm ib_cm crc32_generic rdma_rxe udp_tunnel ib_uverbs ib_core kmem device_dax nd_pmem dax_pmem nd_vme crc32c_intel fuse nvme_core nfit libnvdimm dm_multipath scsi_dh_rdac scsi_dh_emc scsi_dh_alua dm_mirror dm_region_hash dm_log dm_mod
CPU: 0 PID: 26407 Comm: rnbd-client.sh Kdump: loaded Not tainted 6.2.0-rc6-roce-flush+ #53
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
RIP: 0010:__rxe_cleanup+0x13a/0x170 [rdma_rxe]
Code: 45 84 e4 0f 84 5a ff ff ff 48 89 ef e8 5f 18 71 f9 84 c0 75 90 be c8 00 00 00 48 89 ef e8 be 89 1f fa 85 c0 0f 85 7b ff ff ff <0f> 0b 41 bc ea ff ff ff e9 71 ff ff ff e8 84 7f 1f fa e9 d0 fe ff
RSP: 0018:ffffb09880b6f5f0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff99401f15d6a8 RCX: 0000000000000000
RDX: 0000000000000001 RSI: ffffffffbac8234b RDI: 00000000ffffffff
RBP: ffff99401f15d6d0 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000002d82 R11: 0000000000000000 R12: 0000000000000001
R13: ffff994101eff208 R14: ffffb09880b6f6a0 R15: 00000000fffffe00
FS: 00007fe113904740(0000) GS:ffff99413bc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff6cde656c8 CR3: 000000001f108004 CR4: 00000000001706f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
rxe_dealloc_pd+0x16/0x20 [rdma_rxe]
ib_dealloc_pd_user+0x4b/0x80 [ib_core]
rtrs_ib_dev_put+0x79/0xd0 [rtrs_core]
destroy_con_cq_qp+0x8a/0xa0 [rtrs_client]
init_path+0x1e7/0x9a0 [rtrs_client]
? __pfx_autoremove_wake_function+0x10/0x10
? lock_is_held_type+0xd7/0x130
? rcu_read_lock_sched_held+0x43/0x80
? pcpu_alloc+0x3dd/0x7d0
? rtrs_clt_init_stats+0x18/0x40 [rtrs_client]
rtrs_clt_open+0x24f/0x5a0 [rtrs_client]
? __pfx_rnbd_clt_link_ev+0x10/0x10 [rnbd_client]
rnbd_clt_map_device+0x6a5/0xe10 [rnbd_client]

Fixes: 6a98d71daea1 ("RDMA/rtrs: client: main functionality")
Link: https://lore.kernel.org/r/1682384563-2-4-git-send-email-lizhijian@fujitsu.com
Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
Acked-by: Jack Wang <jinpu.wang@ionos.com>
Tested-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs: Remove duplicate cq_num assignment

line 1701 and 1713 are duplicate:
> 1701 cq_num = max_send_wr + max_recv_wr;
1702 /* alloc iu to recv new rkey reply when server reports flags set */
1703 if (clt_path->flags & RTRS_MSG_NEW_RKEY_F || con->c.cid == 0) {
1704 con->rsp_ius = rtrs_iu_alloc(cq_num, sizeof(*rsp),
1705 GFP_KERNEL,
1706 clt_path->s.dev->ib_dev,
1707 DMA_FROM_DEVICE,
1708 rtrs_clt_rdma_done);
1709 if (!con->rsp_ius)
1710 return -ENOMEM;
1711 con->queue_num = cq_num;
1712 }
> 1713 cq_num = max_send_wr + max_recv_wr;

Remove the duplicate.

Link: https://lore.kernel.org/r/1682384563-2-2-git-send-email-lizhijian@fujitsu.com
Acked-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Acked-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

driver core: class: remove module * from class_create()

The module pointer in class_create() never actually did anything, and it
shouldn't have been requred to be set as a parameter even if it did
something. So just remove it and fix up all callers of the function in
the kernel tree at the same time.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Link: https://lore.kernel.org/r/20230313181843.1207845-4-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

RDMA/rtrs-clt: Correct the checking of ib_map_mr_sg

We should check with count, also the only successful case is that
all sg elements are mapped, so make it explicitly.

Acked-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Link: https://lore.kernel.org/r/20221117101945.6317-5-guoqing.jiang@linux.dev
Signed-off-by: Leon Romanovsky <leon@kernel.org>

use less confusing names for iov_iter direction initializers

READ/WRITE proved to be actively confusing - the meanings are
"data destination, as used with read(2)" and "data source, as
used with write(2)", but people keep interpreting those as
"we read data from it" and "we write data to it", i.e. exactly
the wrong way.

Call them ITER_DEST and ITER_SOURCE - at least that is harder
to misinterpret...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[infiniband] READ is "data destination", not source...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

treewide: use get_random_u32_below() instead of deprecated function

This is a simple mechanical transformation done by:

@@
expression E;
@@
- prandom_u32_max
+ get_random_u32_below
(E)

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
Reviewed-by: SeongJae Park <sj@kernel.org> # for damon
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> # for infiniband
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> # for arm
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

treewide: use prandom_u32_max() when possible, part 1

Rather than incurring a division or requesting too many random bytes for
the given range, use the prandom_u32_max() function, which only takes
the minimum required bytes from the RNG and avoids divisions. This was
done mechanically with this coccinelle script:

@basic@
expression E;
type T;
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
typedef u64;
@@
(
- ((T)get_random_u32() % (E))
+ prandom_u32_max(E)
|
- ((T)get_random_u32() & ((E) - 1))
+ prandom_u32_max(E * XXX_MAKE_SURE_E_IS_POW2)
|
- ((u64)(E) * get_random_u32() >> 32)
+ prandom_u32_max(E)
|
- ((T)get_random_u32() & ~PAGE_MASK)
+ prandom_u32_max(PAGE_SIZE)
)

@multi_line@
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
identifier RAND;
expression E;
@@

- RAND = get_random_u32();
... when != RAND
- RAND %= (E);
+ RAND = prandom_u32_max(E);

// Find a potential literal
@literal_mask@
expression LITERAL;
type T;
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
position p;
@@

((T)get_random_u32()@p & (LITERAL))

// Add one to the literal.
@script:python add_one@
literal << literal_mask.LITERAL;
RESULT;
@@

value = None
if literal.startswith('0x'):
value = int(literal, 16)
elif literal[0] in '123456789':
value = int(literal, 10)
if value is None:
print("I don't know how to handle %s" % (literal))
cocci.include_match(False)
elif value == 2**32 - 1 or value == 2**31 - 1 or value == 2**24 - 1 or value == 2**16 - 1 or value == 2**8 - 1:
print("Skipping 0x%x for cleanup elsewhere" % (value))
cocci.include_match(False)
elif value & (value + 1) != 0:
print("Skipping 0x%x because it's not a power of two minus one" % (value))
cocci.include_match(False)
elif literal.startswith('0x'):
coccinelle.RESULT = cocci.make_expr("0x%x" % (value + 1))
else:
coccinelle.RESULT = cocci.make_expr("%d" % (value + 1))

// Replace the literal mask with the calculated result.
@plus_one@
expression literal_mask.LITERAL;
position literal_mask.p;
expression add_one.RESULT;
identifier FUNC;
@@

- (FUNC()@p & (LITERAL))
+ prandom_u32_max(RESULT)

@collapse_ret@
type T;
identifier VAR;
expression E;
@@

{
- T VAR;
- VAR = (E);
- return VAR;
+ return E;
}

@drop_var@
type T;
identifier VAR;
@@

{
- T VAR;
... when != VAR
}

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: KP Singh <kpsingh@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz> # for ext4 and sbitmap
Reviewed-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> # for drbd
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc
Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

RDMA/rtrs-clt: Kill xchg_paths

Let's call try_cmpxchg directly for the same purpose.

Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Link: https://lore.kernel.org/r/20220903040252.29397-1-guoqing.jiang@linux.dev
Signed-off-by: Leon Romanovsky <leon@kernel.org>

RDMA/rtrs-clt: Break the loop once one path is connected

No need to iterate all paths after find one connected path.

Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Link: https://lore.kernel.org/r/20220902101922.26273-3-guoqing.jiang@linux.dev
Signed-off-by: Leon Romanovsky <leon@kernel.org>

RDMA/rtrs-clt: Add event tracing support

Add event tracing mechanism for following routines:
- rtrs_clt_reconnect_work()
- rtrs_clt_close_conns()
- rtrs_rdma_error_recovery()

How to use:
1. Load the rtrs_client module
2. cd /sys/kernel/debug/tracing
3. If all the events need to be enabled:
echo 1 > events/rtrs_clt/enable
4. OR only speific routine/event needs to be enabled e.g.
echo 1 > events/rtrs_clt/rtrs_clt_close_conns/enable
5. cat trace
6. Run some workload which can trigger rtrs_clt_close_conns()

Link: https://lore.kernel.org/r/20220818105240.110234-2-haris.iqbal@ionos.com
Signed-off-by: Santosh 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-clt: Use the right sg_cnt after ib_dma_map_sg

When iommu is enabled, we hit warnings like this:
WARNING: at rtrs/rtrs.c:178 rtrs_iu_post_rdma_write_imm+0x9b/0x110

rtrs warn on one sge entry length is 0, which is unexpected.

The problem is ib_dma_map_sg augments the SGL into a 'dma mapped SGL'.
This process may change the number of entries and the lengths of each
entry.

Code that touches dma_address is iterating over the 'dma mapped SGL'
and must use dma_nents which returned from ib_dma_map_sg().
So pass the count return from ib_dma_map_sg.

Fixes: 6a98d71daea1 ("RDMA/rtrs: client: main functionality")
Link: https://lore.kernel.org/r/20220818105355.110344-3-haris.iqbal@ionos.com
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Reviewed-by: Aleksei Marov <aleksei.marov@ionos.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>

RDMA/rtrs-clt: Replace list_next_or_null_rr_rcu with an inline function

removes list_next_or_null_rr_rcu macro to fix below warnings.
That macro is used only twice.
CHECK:MACRO_ARG_REUSE: Macro argument reuse 'head' - possible side-effects?
CHECK:MACRO_ARG_REUSE: Macro argument reuse 'ptr' - possible side-effects?
CHECK:MACRO_ARG_REUSE: Macro argument reuse 'memb' - possible side-effects?

Replaces that macro with an inline function.

Fixes: 6a98d71daea1 ("RDMA/rtrs: client: main functionality")
Cc: jinpu.wang@ionos.com
Link: https://lore.kernel.org/r/20220712103113.617754-5-haris.iqbal@ionos.com
Signed-off-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Suggested-by: Jason Gunthorpe <jgg@ziepe.ca>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>

RDMA/rtrs-clt: Use bitmap_empty()

Use bitmap_empty() instead of hand-writing them.

Link: https://lore.kernel.org/r/b71ccfaf4a47dee8e1ad373604c861479d499b6b.1657298747.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>

RDMA/rtrs-clt: Use the bitmap API to allocate bitmaps

Use bitmap_zalloc()/bitmap_free() instead of hand-writing them.

It is less verbose and it improves the semantic.

Link: https://lore.kernel.org/r/ca9c5c8301d76d60de34640568b3db0d4401d050.1657298747.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>

RDMA/rtrs-clt: Fix one kernel-doc comment

Add the description of @pathname and remove @sessname in rtrs_clt_open()
kernel-doc comment to remove warnings found by running scripts/kernel-doc,
which is caused by using 'make W=1'.

drivers/infiniband/ulp/rtrs/rtrs-clt.c:2809: warning: Function parameter or member 'pathname' not described in 'rtrs_clt_open'
drivers/infiniband/ulp/rtrs/rtrs-clt.c:2809: warning: Excess function parameter 'sessname' description in 'rtrs_clt_open'

Link: https://lore.kernel.org/r/20220526130945.98601-1-yang.lee@linux.alibaba.com
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Reviewed-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs-clt: Do stop and failover outside reconnect work.

We can't do instant reconnect, not to DDoS server, but we should stop and
failover earlier, so there is less service interruption.

To avoid deadlock, as error_recovery is called from different callback
like rdma event or hb error handler, add a new err recovery_work.

Link: https://lore.kernel.org/r/20220114154753.983568-6-haris.iqbal@ionos.com
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Reviewed-by: Aleksei Marov <aleksei.marov@ionos.com>
Reviewed-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Signed-off-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs-clt: Update one outdated comment in path_it_deinit()

The skip_list is used for both MIN_INFLIGHT and MIN_LATENCY.

Link: https://lore.kernel.org/r/20220114154753.983568-5-haris.iqbal@ionos.com
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs-clt: Move free_permit from free_clt to rtrs_clt_close

Error path of rtrs_clt_open() calls free_clt(), where free_permit is
called. This is wrong since error path of rtrs_clt_open() does not need
to call free_permit().

Also, moving free_permits() call to rtrs_clt_close(), makes it more
aligned with the call to alloc_permit() in rtrs_clt_open().

Fixes: 6a98d71daea1 ("RDMA/rtrs: client: main functionality")
Link: https://lore.kernel.org/r/20220217030929.323849-2-haris.iqbal@ionos.com
Signed-off-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Reviewed-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs-clt: Fix possible double free in error case

Callback function rtrs_clt_dev_release() for put_device() calls kfree(clt)
to free memory. We shouldn't call kfree(clt) again, and we can't use the
clt after kfree too.

Replace device_register() with device_initialize() and device_add() so that
dev_set_name can() be used appropriately.

Move mutex_destroy() to the release function so it can be called in
the alloc_clt err path.

Fixes: eab098246625 ("RDMA/rtrs-clt: Refactor the failure cases in alloc_clt")
Link: https://lore.kernel.org/r/20220217030929.323849-1-haris.iqbal@ionos.com
Reported-by: Miaoqian Lin <linmq006@gmail.com>
Signed-off-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Reviewed-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

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-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: 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-clt: Fix the initial value of min_latency

The type of min_latency is ktime_t, so use KTIME_MAX to initialize the
initial value.

Fixes: dc3b66a0ce70 ("RDMA/rtrs-clt: Add a minimum latency multipath policy")
Link: https://lore.kernel.org/r/20211124081040.19533-1-jinpu.wang@ionos.com
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Reviewed-by: Guoqing Jiang <Guoqing.Jiang@linux.dev>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs: Do not allow sessname to contain special symbols / and .

Allowing these characters in sessname can lead to unexpected results,
particularly because / is used as a separator between files in a path, and
. points to the current directory.

Link: https://lore.kernel.org/r/20210922125333.351454-7-haris.iqbal@ionos.com
Signed-off-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Reviewed-by: Gioh Kim <gi-oh.kim@ionos.com>
Reviewed-by: Aleksei Marov <aleksei.marov@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs-clt: Fix counting inflight IO

There are mis-match at counting inflight IO after changing the multipath
policy.

For example, we started fio test with round-robin policy and then we
changed the policy to min-inflight. IOs created under the RR policy is
finished under the min-inflight policy and inflight counter only
decreased. So the counter would be negative value. And also we started
fio test with min-inflight policy and changed the policy to the
round-robin. IOs created under the min-inflight policy increased the
inflight IO counter but the inflight IO counter was not decreased because
the policy was the round-robin when IO was finished.

So it should count IOs only if the IO is created under the min-inflight
policy. It should not care the policy when the IO is finished.

This patch adds a field mp_policy in struct rtrs_clt_io_req and stores the
multipath policy when an object of rtrs_clt_io_req is created. Then
rtrs-clt checks the mp_policy of only struct rtrs_clt_io_req instead of
the struct rtrs_clt.

Link: https://lore.kernel.org/r/20210806112112.124313-6-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: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs: Remove all likely and unlikely

The IO performance test with fio after swapping the likely and unlikely
macros in all if-statement shows no difference. They do not help for the
performance of rtrs.

Thanks to Haakon Bugge for the test scenario.

The fio test did random read on 32 rnbd devices and 64 processes.
Test environment:
- Intel(R) Xeon(R) Gold 6130 CPU @ 2.10GHz
- 376G memory
- kernel version: 5.4.86
- gcc version: gcc (Debian 8.3.0-6) 8.3.0
- Infiniband controller: Mellanox Technologies MT27800 Family [ConnectX-5]

Test result:
- before swapping: IOPS=829k, BW=3239MiB/s
- after swapping: IOPS=829k, BW=3238MiB/s
- remove all (un)likely: IOPS=829k, BW=3238MiB/s

Link: https://lore.kernel.org/r/20210806112112.124313-5-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: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs-clt: During add_path change for_new_clt according to path_num

When all the paths are removed for a session, the addition of the first
path is like a new session for the storage server.

Hence, for_new_clt has to be set to 1.

Link: https://lore.kernel.org/r/20210806112112.124313-2-haris.iqbal@ionos.com
Signed-off-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs: Remove a useless kfree()

'sess->rbufs' is known to be NULL here, so there is no point in kfree'ing
it.

Fixes: 6a98d71daea1 ("RDMA/rtrs: client: main functionality")
Link: https://lore.kernel.org/r/9a57c9f837fa2c6f0070578a1bc4840688f62962.1628185335.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs: Move sq_wr_avail to rtrs_con

In order to account HB for sq_wr_avail properly, move sq_wr_avail from
rtrs_srv_con to rtrs_con.

Although rtrs-clt do not care sq_wr_avail, but still init it to
max_send_wr.

Fixes: b38041d50add ("RDMA/rtrs: Do not signal for heatbeat")
Link: https://lore.kernel.org/r/20210712060750.16494-7-jinpu.wang@ionos.com
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Reviewed-by: Aleksei Marov <aleksei.marov@ionos.com>
Reviewed-by: Gioh Kim <gi-oh.kim@ionos.com>
Reviewed-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs: Enable the same selective signal for heartbeat and IO

On idle session, because we do not do signal for heartbeat, it will
overflow the send queue after sometime.

To avoid that, we need to enable the signal for heartbeat. To do that, add
a new member signal_interval in rtrs_path, which will set min of
queue_depth and SERVICE_CON_QUEUE_DEPTH, and track it for both heartbeat
and IO, so the sq queue full accounting is correct.

Fixes: b38041d50add ("RDMA/rtrs: Do not signal for heatbeat")
Link: https://lore.kernel.org/r/20210712060750.16494-4-jinpu.wang@ionos.com
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Reviewed-by: Aleksei Marov <aleksei.marov@ionos.com>
Reviewed-by: Gioh Kim <gi-oh.kim@ionos.com>
Reviewed-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs: move wr_cnt from rtrs_srv_con to rtrs_con

We need to track also the wr used for heatbeat. This is a preparation for
that, will be used in later patch.

The io_cnt in rtrs_clt is removed, use wr_cnt instead.

Link: https://lore.kernel.org/r/20210712060750.16494-3-jinpu.wang@ionos.com
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Reviewed-by: Aleksei Marov <aleksei.marov@ionos.com>
Reviewed-by: Gioh Kim <gi-oh.kim@ionos.com>
Reviewed-by: Md Haris Iqbal <haris.iqbal@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-clt: Raise MAX_SEGMENTS

As we can do fast memory registration on write, we can increase
the max_segments, default to 512K.

Link: https://lore.kernel.org/r/20210621055340.11789-5-jinpu.wang@ionos.com
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_clt: Alloc less memory with write path fast memory registration

With write path fast memory registration, we need less memory for
each request.

With fast memory registration, we can reduce max_send_sge to save
memory usage.

Also convert the kmalloc_array to kcalloc.

Link: https://lore.kernel.org/r/20210621055340.11789-4-jinpu.wang@ionos.com
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-clt: Write path fast memory registration

With fast memory registration in write path, we can reduce
the memory consumption by using less max_send_sge, support IO bigger
than 116 KB (29 segments * 4 KB) without splitting, and it also
make the IO path more symmetric.

To avoid some times MR reg failed, waiting for the invalidation to finish
before the new mr reg. Introduce a refcount, only finish the request
when both local invalidation and io reply are there.

Link: https://lore.kernel.org/r/20210621055340.11789-3-jinpu.wang@ionos.com
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Signed-off-by: Dima Stepanov <dmitrii.stepanov@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs: Introduce head/tail wr

Introduce tail wr, we can send as the last wr, we want to send the local
invalidate wr after rdma wr in later patch.

While at it, also fix coding style issue.

Link: https://lore.kernel.org/r/20210621055340.11789-2-jinpu.wang@ionos.com
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: Fix kernel-doc warnings about wrong comment

Compilation with W=1 produces warnings similar to the below.

drivers/infiniband/ulp/ipoib/ipoib_main.c:320: warning: This comment
starts with '/**', but isn't a kernel-doc comment. Refer
Documentation/doc-guide/kernel-doc.rst

All such occurrences were found with the following one line
git grep -A 1 "\/\*\*" drivers/infiniband/

Link: https://lore.kernel.org/r/e57d5f4ddd08b7a19934635b44d6d632841b9ba7.1623823612.git.leonro@nvidia.com
Reviewed-by: Jack Wang <jinpu.wang@ionos.com> #rtrs
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs: Check device max_qp_wr limit when create QP

Currently we only check device max_qp_wr limit for IO connection, but not
for service connection. We should check for both.

So save the max_qp_wr device limit in wr_limit, and use it for both IO
connections and service connections.

While at it, also remove an outdated comments.

Link: https://lore.kernel.org/r/20210614090337.29557-6-jinpu.wang@ionos.com
Suggested-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Gioh Kim <gi-oh.kim@ionos.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs: Rename cq_size/queue_size to cq_num/queue_num

Those variables are passed to create_cq, create_qp, rtrs_iu_alloc and
rtrs_iu_free, so these *_size means the num of unit. And cq_size also
means number of cq element.

Also move the setting of cq_num to common path.

Link: https://lore.kernel.org/r/20210614090337.29557-5-jinpu.wang@ionos.com
Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Reviewed-by: Md Haris Iqbal <haris.iqbal@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: RDMA_RXE requires more number of WR

When using rdma_rxe, post_one_recv() returns ENOMEM error due to the full
recv queue. This patch increase the number of WR for receive queue to
support all devices.

Link: https://lore.kernel.org/r/20210614090337.29557-4-jinpu.wang@ionos.com
Signed-off-by: Md Haris Iqbal <haris.iqbal@cloud.ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Gioh Kim <gi-oh.kim@ionos.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs-clt: Use minimal max_send_sge when create qp

We use device limit max_send_sge, which is suboptimal for memory usage.
We don't need that much for User Con, 1 is enough. And for IO con,
sess->max_segments + 1 is enough

Link: https://lore.kernel.org/r/20210614090337.29557-3-jinpu.wang@ionos.com
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs: Avoid Wtautological-constant-out-of-range-compare

drivers/infiniband/ulp/rtrs/rtrs-clt.c:1786:19: warning: result of comparison of
constant 'MAX_SESS_QUEUE_DEPTH' (65536) with expression of type 'u16'
(aka 'unsigned short') is always false [-Wtautological-constant-out-of-range-compare]

To fix it, limit MAX_SESS_QUEUE_DEPTH to u16 max, which is 65535, and
drop the check in rtrs-clt, as it's the type u16 max.

Link: https://lore.kernel.org/r/20210531122835.58329-1-jinpu.wang@ionos.com
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs-clt: Fix memory leak of not-freed sess->stats and stats->pcpu_stats

sess->stats and sess->stats->pcpu_stats objects are freed
when sysfs entry is removed. If something wrong happens and
session is closed before sysfs entry is created,
sess->stats and sess->stats->pcpu_stats objects are not freed.

This patch adds freeing of them at three places:
1. When client uses wrong address and session creation fails.
2. When client fails to create a sysfs entry.
3. When client adds wrong address via sysfs add_path.

Fixes: 215378b838df0 ("RDMA/rtrs: client: sysfs interface functions")
Link: https://lore.kernel.org/r/20210528113018.52290-21-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-clt: Check if the queue_depth has changed during a reconnection

The queue_depth is a module parameter for rtrs_server. It is used on the
client side to determing the queue_depth of the request queue for the RNBD
virtual block device.

During a reconnection event for an already mapped device, in case the
rtrs_server module queue_depth has changed, fail the reconnect attempt.

Also stop further auto reconnection attempts. A manual reconnect via
sysfs has to be triggerred.

Fixes: 6a98d71daea18 ("RDMA/rtrs: client: main functionality")
Link: https://lore.kernel.org/r/20210528113018.52290-20-jinpu.wang@ionos.com
Signed-off-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>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs-clt: Check state of the rtrs_clt_sess before reading its stats

When get_next_path_min_inflight is called to select the next path, it
iterates over the list of available rtrs_clt_sess (paths). It then reads
the number of inflight IOs for that path to select one which has the least
inflight IO.

But it may so happen that rtrs_clt_sess (path) is no longer in the
connected state because closing or error recovery paths can change the status
of the rtrs_clt_Sess.

For example, the client sent the heart-beat and did not get the
response, it would change the session status and stop IO processing.
The added checking of this patch can prevent accessing the broken path
and generating duplicated error messages.

It is ok if the status is changed after checking the status because
the error recovery path does not free memory and only tries to
reconnection. And also it is ok if the session is closed after checking
the status because closing the session changes the session status and
flush all IO beforing free memory. If the session is being accessed for
IO processing, the closing session will wait.

Fixes: 6a98d71daea18 ("RDMA/rtrs: client: main functionality")
Link: https://lore.kernel.org/r/20210528113018.52290-13-jinpu.wang@ionos.com
Signed-off-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Reviewed-by: Gioh Kim <gi-oh.kim@ionos.com>
Signed-off-by: Gioh Kim <gi-oh.kim@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs-clt: Remove redundant 'break'

It is duplicated with the very next line

Link: https://lore.kernel.org/r/20210528113018.52290-12-jinpu.wang@ionos.com
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: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs-clt: Kill rtrs_clt_disconnect_from_sysfs

The function is just a wrapper of rtrs_clt_close_conns, let's call
rtrs_clt_close_conns directly.

Link: https://lore.kernel.org/r/20210528113018.52290-10-jinpu.wang@ionos.com
Signed-off-by: Guoqing Jiang <guoqing.jiang@ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Gioh Kim <gi-oh.kim@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs-clt: Kill rtrs_clt_{start,stop}_hb

The two wrappers are not needed since we can call rtrs_{start,stop}_hb
directly.

Link: https://lore.kernel.org/r/20210528113018.52290-9-jinpu.wang@ionos.com
Signed-off-by: Guoqing Jiang <guoqing.jiang@ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Gioh Kim <gi-oh.kim@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs: Use strscpy instead of strlcpy

During checkpatch analyzing the following warning message was found:
WARNING:STRLCPY: Prefer strscpy over strlcpy - see:
https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/
Fix it by using strscpy calls instead of strlcpy.

Link: https://lore.kernel.org/r/20210528113018.52290-8-jinpu.wang@ionos.com
Signed-off-by: Dima Stepanov <dmitrii.stepanov@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-clt: Remove MAX_SESS_QUEUE_DEPTH from rtrs_send_sess_info

Client receives queue_depth value from server. There is no need
to use MAX_SESS_QUEUE_DEPTH value.

Link: https://lore.kernel.org/r/20210528113018.52290-3-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: fix uninitialized symbol 'cnt'

rtrs_clt_rdma_cq_direct returns an ninitialized value in cnt
if there is no session. This patch makes rtrs_clt_rdma_cq_direct
returns a negative value for block layer not to try again.

Fixes: 2958a995edc94 ("block/rnbd-clt: Support polling mode for IO latency optimization")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Gioh Kim <gi-oh.kim@ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Link: https://lore.kernel.org/r/20210429092741.266533-1-gi-oh.kim@ionos.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

RDMA/rtrs-clt: Simplify error message

Two error messages are only different message but have common
code to generate the path string.

Link: https://lore.kernel.org/r/20210406123639.202899-4-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-clt: Print more info when an error happens

Client prints only error value and it is not enough for debugging.

1. When client receives an error from server: the client does not only
print the error value but also more information of server connection.

2. When client failes to send IO: the client gets an error from RDMA
layer. It also print more information of server connection.

Link: https://lore.kernel.org/r/20210406123639.202899-2-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-clt: Add a minimum latency multipath policy

This patch adds new multipath policy: min-latency. Client checks the
latency of each path when it sends the heart-beat. And it sends IO to the
path with the minimum latency.

Link: https://lore.kernel.org/r/20210407113444.150961-2-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-clt: destroy sysfs after removing session from active list

A session can be removed dynamically by sysfs interface "remove_path" that
eventually calls rtrs_clt_remove_path_from_sysfs function. The current
rtrs_clt_remove_path_from_sysfs first removes the sysfs interfaces and
frees sess->stats object. Second it removes the session from the active
list.

Therefore some functions could access non-connected session and access the
freed sess->stats object even-if they check the session status before
accessing the session.

For instance rtrs_clt_request and get_next_path_min_inflight check the
session status and try to send IO to the session. The session status
could be changed when they are trying to send IO but they could not catch
the change and update the statistics information in sess->stats object,
and generate use-after-free problem.
(see: "RDMA/rtrs-clt: Check state of the rtrs_clt_sess before reading its
stats")

This patch changes the rtrs_clt_remove_path_from_sysfs to remove the
session from the active session list and then destroy the sysfs
interfaces.

Each function still should check the session status because closing or
error recovery paths can change the status.

Fixes: 6a98d71daea1 ("RDMA/rtrs: client: main functionality")
Link: https://lore.kernel.org/r/20210412084002.33582-1-gi-oh.kim@ionos.com
Signed-off-by: Gioh Kim <gi-oh.kim@ionos.com>
Reviewed-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs-clt: Cap max_io_size

Max io size is limited by both remote buffer size and the max fr pages per
mr.

Link: https://lore.kernel.org/r/20210325153308.1214057-20-gi-oh.kim@ionos.com
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>
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>

RDMA/rtrs-clt: Remove redundant code from rtrs_clt_read_req

There is no need to dereference 's' from 'sess', since we have "sess =
to_clt_sess(s)" before.

And we can deference 'dev' from 's' earlier.

Link: https://lore.kernel.org/r/20210325153308.1214057-8-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-clt: Use rdma_event_msg in log

It's easier to understand a string instead of enum.

Link: https://lore.kernel.org/r/20210222141551.54345-2-jinpu.wang@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: Use new shared CQ mechanism

Have the driver use shared CQs which provids a ~10%-20% improvement during
test.

Instead of opening a CQ for each QP per connection, a CQ for each QP will
be provided by the RDMA core driver that will be shared between the QPs on
that core reducing interrupt overhead.

Link: https://lore.kernel.org/r/20210222141551.54345-1-jinpu.wang@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>

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-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>

RDMA/rtrs-clt: Close rtrs client conn before destroying rtrs clt session files

KASAN detected the following BUG:

BUG: KASAN: use-after-free in rtrs_clt_update_wc_stats+0x41/0x100 [rtrs_client]
Read of size 8 at addr ffff88bf2fb4adc0 by task swapper/0/0

CPU: 0 PID: 0 Comm: swapper/0 Tainted: G O 5.4.84-pserver #5.4.84-1+feature+linux+5.4.y+dbg+20201216.1319+b6b887b~deb10
Hardware name: Supermicro H8QG6/H8QG6, BIOS 3.00 09/04/2012
Call Trace:
<IRQ>
dump_stack+0x96/0xe0
print_address_description.constprop.4+0x1f/0x300
? irq_work_claim+0x2e/0x50
__kasan_report.cold.8+0x78/0x92
? rtrs_clt_update_wc_stats+0x41/0x100 [rtrs_client]
kasan_report+0x10/0x20
rtrs_clt_update_wc_stats+0x41/0x100 [rtrs_client]
rtrs_clt_rdma_done+0xb1/0x760 [rtrs_client]
? lockdep_hardirqs_on+0x1a8/0x290
? process_io_rsp+0xb0/0xb0 [rtrs_client]
? mlx4_ib_destroy_cq+0x100/0x100 [mlx4_ib]
? add_interrupt_randomness+0x1a2/0x340
__ib_process_cq+0x97/0x100 [ib_core]
ib_poll_handler+0x41/0xb0 [ib_core]
irq_poll_softirq+0xe0/0x260
__do_softirq+0x127/0x672
irq_exit+0xd1/0xe0
do_IRQ+0xa3/0x1d0
common_interrupt+0xf/0xf
</IRQ>
RIP: 0010:cpuidle_enter_state+0xea/0x780
Code: 31 ff e8 99 48 47 ff 80 7c 24 08 00 74 12 9c 58 f6 c4 02 0f 85 53 05 00 00 31 ff e8 b0 6f 53 ff e8 ab 4f 5e ff fb 8b 44 24 04 <85> c0 0f 89 f3 01 00 00 48 8d 7b 14 e8 65 1e 77 ff c7 43 14 00 00
RSP: 0018:ffffffffab007d58 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffca
RAX: 0000000000000002 RBX: ffff88b803d69800 RCX: ffffffffa91a8298
RDX: 0000000000000007 RSI: dffffc0000000000 RDI: ffffffffab021414
RBP: ffffffffab6329e0 R08: 0000000000000002 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000002
R13: 000000bf39d82466 R14: ffffffffab632aa0 R15: ffffffffab632ae0
? lockdep_hardirqs_on+0x1a8/0x290
? cpuidle_enter_state+0xe5/0x780
cpuidle_enter+0x3c/0x60
do_idle+0x2fb/0x390
? arch_cpu_idle_exit+0x40/0x40
? schedule+0x94/0x120
cpu_startup_entry+0x19/0x1b
start_kernel+0x5da/0x61b
? thread_stack_cache_init+0x6/0x6
? load_ucode_amd_bsp+0x6f/0xc4
? init_amd_microcode+0xa6/0xa6
? x86_family+0x5/0x20
? load_ucode_bsp+0x182/0x1fd
secondary_startup_64+0xa4/0xb0

Allocated by task 5730:
save_stack+0x19/0x80
__kasan_kmalloc.constprop.9+0xc1/0xd0
kmem_cache_alloc_trace+0x15b/0x350
alloc_sess+0xf4/0x570 [rtrs_client]
rtrs_clt_open+0x3b4/0x780 [rtrs_client]
find_and_get_or_create_sess+0x649/0x9d0 [rnbd_client]
rnbd_clt_map_device+0xd7/0xf50 [rnbd_client]
rnbd_clt_map_device_store+0x4ee/0x970 [rnbd_client]
kernfs_fop_write+0x141/0x240
vfs_write+0xf3/0x280
ksys_write+0xba/0x150
do_syscall_64+0x68/0x270
entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 5822:
save_stack+0x19/0x80
__kasan_slab_free+0x125/0x170
kfree+0xe7/0x3f0
kobject_put+0xd3/0x240
rtrs_clt_destroy_sess_files+0x3f/0x60 [rtrs_client]
rtrs_clt_close+0x3c/0x80 [rtrs_client]
close_rtrs+0x45/0x80 [rnbd_client]
rnbd_client_exit+0x10f/0x2bd [rnbd_client]
__x64_sys_delete_module+0x27b/0x340
do_syscall_64+0x68/0x270
entry_SYSCALL_64_after_hwframe+0x49/0xbe

When rtrs_clt_close is triggered, it iterates over all the present
rtrs_clt_sess and triggers close on them. However, the call to
rtrs_clt_destroy_sess_files is done before the rtrs_clt_close_conns. This
is incorrect since during the initialization phase we allocate
rtrs_clt_sess first, and then we go ahead and create rtrs_clt_con for it.

If we free the rtrs_clt_sess structure before closing the rtrs_clt_con, it
may so happen that an inflight IO completion would trigger the function
rtrs_clt_rdma_done, which would lead to the above UAF case.

Hence close the rtrs_clt_con connections first, and then trigger the
destruction of session files.

Fixes: 6a98d71daea1 ("RDMA/rtrs: client: main functionality")
Link: https://lore.kernel.org/r/20210325153308.1214057-12-gi-oh.kim@ionos.com
Signed-off-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Gioh Kim <gi-oh.kim@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs: Only allow addition of path to an already established session

While adding a path from the client side to an already established
session, it was possible to provide the destination IP to a different
server. This is dangerous.

This commit adds an extra member to the rtrs_msg_conn_req structure, named
first_conn; which is supposed to notify if the connection request is the
first for that session or not.

On the server side, if a session does not exist but the first_conn
received inside the rtrs_msg_conn_req structure is 1, the connection
request is failed. This signifies that the connection request is for an
already existing session, and since the server did not find one, it is an
wrong connection request.

Fixes: 6a98d71daea1 ("RDMA/rtrs: client: main functionality")
Fixes: 9cb837480424 ("RDMA/rtrs: server: main functionality")
Link: https://lore.kernel.org/r/20210212134525.103456-3-jinpu.wang@cloud.ionos.com
Signed-off-by: Md Haris Iqbal <haris.iqbal@cloud.ionos.com>
Reviewed-by: Lutz Pogrell <lutz.pogrell@cloud.ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs-clt: Use bitmask to check sess->flags

We may want to add new flags, so it's better to use bitmask to check flags.

Fixes: 6a98d71daea1 ("RDMA/rtrs: client: main functionality")
Link: https://lore.kernel.org/r/20201217141915.56989-17-jinpu.wang@cloud.ionos.com
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Gioh Kim <gi-oh.kim@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs: Do not signal for heatbeat

For HB, there is no need to generate signal for completion.

Also remove a comment accordingly.

Fixes: c0894b3ea69d ("RDMA/rtrs: core: lib functions shared between client and server modules")
Link: https://lore.kernel.org/r/20201217141915.56989-16-jinpu.wang@cloud.ionos.com
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Reported-by: Gioh Kim <gi-oh.kim@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs-clt: Refactor the failure cases in alloc_clt

Make all failure cases go to the common path to avoid duplicate code.
And some issued existed before.

1. clt need to be freed to avoid memory leak.

2. return ERR_PTR(-ENOMEM) if kobject_create_and_add fails, because
rtrs_clt_open checks the return value of by call "IS_ERR(clt)".

Fixes: 6a98d71daea1 ("RDMA/rtrs: client: main functionality")
Link: https://lore.kernel.org/r/20201217141915.56989-15-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>
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs-clt: Rename __rtrs_clt_change_state to rtrs_clt_change_state

Let's rename it to rtrs_clt_change_state since the previous one is
killed.

Also update the comment to make it more clear.

Link: https://lore.kernel.org/r/20201217141915.56989-13-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>
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs-clt: Kill rtrs_clt_change_state

It is just a wrapper of rtrs_clt_change_state_get_old, and we can reuse
rtrs_clt_change_state_get_old with add the checking of 'old_state' is
valid or not.

Link: https://lore.kernel.org/r/20201217141915.56989-12-jinpu.wang@cloud.ionos.com
Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs-clt: Remove unnecessary 'goto out'

This is not needed since the label is just after the place.

Link: https://lore.kernel.org/r/20201217141915.56989-11-jinpu.wang@cloud.ionos.com
Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs-clt: Kill wait_for_inflight_permits

Let's wait the inflight permits before free it.

Link: https://lore.kernel.org/r/20201217141915.56989-10-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>
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs-clt: Consolidate rtrs_clt_destroy_sysfs_root_{folder,files}

Since the two functions are called together, let's consolidate them in
a new function rtrs_clt_destroy_sysfs_root.

Link: https://lore.kernel.org/r/20201217141915.56989-9-jinpu.wang@cloud.ionos.com
Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs-clt: Set mininum limit when create QP

Currently rtrs when create_qp use a coarse numbers (bigger in general),
which leads to hardware create more resources which only waste memory
with no benefits.

- SERVICE con,
For max_send_wr/max_recv_wr, it's 2 times SERVICE_CON_QUEUE_DEPTH + 2

- IO con
For max_send_wr/max_recv_wr, it's sess->queue_depth * 3 + 1

Fixes: 6a98d71daea1 ("RDMA/rtrs: client: main functionality")
Link: https://lore.kernel.org/r/20201217141915.56989-6-jinpu.wang@cloud.ionos.com
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: Extend ibtrs_cq_qp_create

rtrs does not have same limit for both max_send_wr and max_recv_wr,
To allow client and server set different values, export in a separate
parameter for rtrs_cq_qp_create.

Also fix the type accordingly, u32 should be used instead of u16.

Fixes: c0894b3ea69d ("RDMA/rtrs: core: lib functions shared between client and server modules")
Link: https://lore.kernel.org/r/20201217141915.56989-2-jinpu.wang@cloud.ionos.com
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: 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>

RDMA/rtrs-clt: Remove 'addr' from rtrs_clt_add_path_to_arr

Remove the argument since it is not used in the function.

Link: https://lore.kernel.org/r/20201023074353.21946-13-jinpu.wang@cloud.ionos.com
Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs-clt: Remove duplicated code

process_info_rsp checks that sg_cnt is zero twice.

Link: https://lore.kernel.org/r/20201023074353.21946-10-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-clt: Remove duplicated switch-case handling for CM error events

The events returning the same error value are put together.

Link: https://lore.kernel.org/r/20201023074353.21946-9-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: Remove unnecessary argument dir of rtrs_iu_free

The direction of DMA operation is already in the rtrs_iu

Link: https://lore.kernel.org/r/20201023074353.21946-8-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-clt: Missing error from rtrs_rdma_conn_established

When rtrs_rdma_conn_established returns error (non-zero value), the error
value is stored in con->cm_err and it cannot trigger
rtrs_rdma_error_recovery. Finally the error of rtrs_rdma_con_established
will be forgot.

Fixes: 6a98d71daea1 ("RDMA/rtrs: client: main functionality")
Link: https://lore.kernel.org/r/20201023074353.21946-5-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>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs-clt: Avoid run destroy_con_cq_qp/create_con_cq_qp in parallel

It could happen two kworkers race with each other:

CPU0 CPU1
addr_resolver kworker reconnect kworker
rtrs_clt_rdma_cm_handler
rtrs_rdma_addr_resolved
create_con_cq_qp: s.dev_ref++
"s.dev_ref is 1"
wait in create_cm fails with TIMEOUT
destroy_con_cq_qp: --s.dev_ref
"s.dev_ref is 0"
destroy_con_cq_qp: sess->s.dev = NULL
rtrs_cq_qp_create -> create_qp(con, sess->dev->ib_pd...)
sess->dev is NULL, panic.

To fix the problem using mutex to serialize create_con_cq_qp and
destroy_con_cq_qp.

Fixes: 6a98d71daea1 ("RDMA/rtrs: client: main functionality")
Link: https://lore.kernel.org/r/20201023074353.21946-4-jinpu.wang@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: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs-clt: Remove outdated comment in create_con_cq_qp

As run destroy_con_cq_qp many times doesn't work, remove the comments.

Fixes: 6a98d71daea1 ("RDMA/rtrs: client: main functionality")
Link: https://lore.kernel.org/r/20201023074353.21946-3-jinpu.wang@cloud.ionos.com
Suggested-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-clt: Remove destroy_con_cq_qp in case route resolving failed

We call destroy_con_cq_qp(con) in rtrs_rdma_addr_resolved() in case route
couldn't be resolved and then again in create_cm() because nothing
happens.

Don't call destroy_con_cq_qp from rtrs_rdma_addr_resolved, create_cm()
does the clean up already.

Fixes: 6a98d71daea1 ("RDMA/rtrs: client: main functionality")
Link: https://lore.kernel.org/r/20201023074353.21946-2-jinpu.wang@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@nvidia.com>

RDMA: Add rdma_connect_locked()

There are two flows for handling RDMA_CM_EVENT_ROUTE_RESOLVED, either the
handler triggers a completion and another thread does rdma_connect() or
the handler directly calls rdma_connect().

In all cases rdma_connect() needs to hold the handler_mutex, but when
handler's are invoked this is already held by the core code. This causes
ULPs using the 2nd method to deadlock.

Provide a rdma_connect_locked() and have all ULPs call it from their
handlers.

Link: https://lore.kernel.org/r/0-v2-53c22d5c1405+33-rdma_connect_locking_jgg@nvidia.com
Reported-and-tested-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Fixes: 2a7cec538169 ("RDMA/cma: Fix locking for the RDMA_CM_CONNECT state")
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Acked-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs: remove WQ_MEM_RECLAIM for rtrs_wq

lockdep triggers a warning from time to time when running a regression
test:

rnbd_client L685: </dev/nullb0@bla> Device disconnected.
rnbd_client L1756: Unloading module

workqueue: WQ_MEM_RECLAIM rtrs_client_wq:rtrs_clt_reconnect_work [rtrs_client] is flushing !WQ_MEM_RECLAIM ib_addr:process_one_req [ib_core]
WARNING: CPU: 2 PID: 18824 at kernel/workqueue.c:2517 check_flush_dependency+0xad/0x130

The root cause is workqueue core expect flushing should not be done for a
!WQ_MEM_RECLAIM wq from a WQ_MEM_RECLAIM workqueue.

In above case ib_addr workqueue without WQ_MEM_RECLAIM, but rtrs_wq
WQ_MEM_RECLAIM.

To avoid the warning, remove the WQ_MEM_RECLAIM flag.

Fixes: 9cb837480424 ("RDMA/rtrs: server: main functionality")
Fixes: 6a98d71daea1 ("RDMA/rtrs: client: main functionality")
Link: https://lore.kernel.org/r/20200724111508.15734-4-haris.iqbal@cloud.ionos.com
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Md Haris Iqbal <haris.iqbal@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs-clt: add an additional random 8 seconds before reconnecting

In order to avoid all the clients to start reconnecting at the same time
schedule the reconnect dwork with a random jitter of +[0,8] seconds.

Fixes: 6a98d71daea1 ("RDMA/rtrs: client: main functionality")
Link: https://lore.kernel.org/r/20200724111508.15734-2-haris.iqbal@cloud.ionos.com
Signed-off-by: Danil Kipnis <danil.kipnis@cloud.ionos.com>
Signed-off-by: Md Haris Iqbal <haris.iqbal@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/rtrs: Get rid of the do_next_path while_next_path macros

The macros do_each_path/while_each_path lead to a smatch warning:

drivers/infiniband/ulp/rtrs/rtrs-clt.c:1196 rtrs_clt_failover_req() warn: inconsistent indenting
drivers/infiniband/ulp/rtrs/rtrs-clt.c:2890 rtrs_clt_request() warn: inconsistent indenting

Also checkpatch complains:
ERROR: Macros with multiple statements should be enclosed in a do - while loop

The macros are used only in two places: for a normal IO path and for the
failover path triggered after errors.

Get rid of the macros and just use a for loop iterating over the list of
paths in both places. It is easier to read and also less lines of code.

Fixes: 6a98d71daea1 ("RDMA/rtrs: client: main functionality")
Link: https://lore.kernel.org/r/20200522053924.528980-1-danil.kipnis@cloud.ionos.com
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Danil Kipnis <danil.kipnis@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

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: client: Fix function return on success

Remove the if-statement and return the value contained in _err_,
unconditionally.

Link: https://lore.kernel.org/r/20200519163612.GA6043@embeddedor
Addresses-Coverity-ID: 1493753 ("Identical code for different branches")
Fixes: 6a98d71daea1 ("RDMA/rtrs: client: main functionality")
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

RDMA/rtrs: Fix some signedness bugs in error handling

The problem is that "req->sg_cnt" is an unsigned int so if "nr" is
negative, it gets type promoted to a high positive value and the condition
is false. This patch fixes it by handling negatives separately.

Fixes: 6a98d71daea1 ("RDMA/rtrs: client: main functionality")
Link: https://lore.kernel.org/r/20200519133223.GN2078@kadam
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

RDMA/rtrs: client: main functionality

This is main functionality of rtrs-client module, which manages set of
RDMA connections for each rtrs session, does multipathing, load balancing
and failover of RDMA requests.

Link: https://lore.kernel.org/r/20200511135131.27580-7-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>