When a SMC-D link group is freed, a shutdown signal should be sent to
the peer to indicate that the link group is invalid. This patch adds the
shutdown signal to the SMC code.
Signed-off-by: NHans Wippel <hwippel@linux.ibm.com>
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When searching for an existing link group the queue pair number is also
to be taken into consideration. When the SMC server sends a new number
in a CLC packet (keeping all other values equal) then a new link group
is to be created on the SMC client side.
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In case of a non-blocking SMC socket, the initial CLC handshake is
performed over a blocking TCP connection in a worker. If the SMC socket
is released, smc_release has to wait for the blocking CLC socket
operations (e.g., kernel_connect) inside the worker.

This patch aborts a CLC connection when the respective non-blocking SMC
socket is released to avoid waiting on socket operations or timeouts.
Signed-off-by: NHans Wippel <hwippel@linux.ibm.com>
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The pointer to the link group is unset in the smc connection structure
right before the call to smc_buf_unuse. Provide the lgr pointer to
smc_buf_unuse explicitly.
And move the call to smc_lgr_schedule_free_work to the end of
smc_conn_free.

Fixes: a6920d1d ("net/smc: handle unregistered buffers")
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In the iov_iter struct, separate the iterator type from the iterator
direction and use accessor functions to access them in most places.

Convert a bunch of places to use switch-statements to access them rather
then chains of bitwise-AND statements.  This makes it easier to add further
iterator types.  Also, this can be more efficient as to implement a switch
of small contiguous integers, the compiler can use ~50% fewer compare
instructions than it has to use bitwise-and instructions.

Further, cease passing the iterator type into the iterator setup function.
The iterator function can set that itself.  Only the direction is required.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

This reverts commit dd979b4d.

This broke tcp_poll for SMC fallback: An AF_SMC socket establishes an
internal TCP socket for the initial handshake with the remote peer.
Whenever the SMC connection can not be established this TCP socket is
used as a fallback. All socket operations on the SMC socket are then
forwarded to the TCP socket. In case of poll, the file->private_data
pointer references the SMC socket because the TCP socket has no file
assigned. This causes tcp_poll to wait on the wrong socket.
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The generic netlink family is only initialized during module init,
so it should be __ro_after_init like all other generic netlink
families.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Comparing an int to a size, which is unsigned, causes the int to become
unsigned, giving the wrong result. kernel_sendmsg can return a negative
error code.
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Don't check a listen socket for pending urgent data in smc_poll().
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If a linkgroup is terminated abnormally already due to failing
LLC CONFIRM LINK or LLC ADD LINK, fallback to TCP is still possible.
In this case do not switch to state SMC_PEERABORTWAIT and do not set
sk_err.
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For a failing smc_listen_rdma_finish() smc_listen_decline() is
called. If fallback is possible, the new socket is already enqueued
to be accepted in smc_listen_decline(). Avoid enqueuing a second time
afterwards in this case, otherwise the smc_create_lgr_pending lock
is released twice:
[  373.463976] WARNING: bad unlock balance detected!
[  373.463978] 4.18.0-rc7+ #123 Tainted: G           O
[  373.463979] -------------------------------------
[  373.463980] kworker/1:1/30 is trying to release lock (smc_create_lgr_pending) at:
[  373.463990] [<000003ff801205fc>] smc_listen_work+0x22c/0x5d0 [smc]
[  373.463991] but there are no more locks to release!
[  373.463991]
other info that might help us debug this:
[  373.463993] 2 locks held by kworker/1:1/30:
[  373.463994]  #0: 00000000772cbaed ((wq_completion)"events"){+.+.}, at: process_one_work+0x1ec/0x6b0
[  373.464000]  #1: 000000003ad0894a ((work_completion)(&new_smc->smc_listen_work)){+.+.}, at: process_one_work+0x1ec/0x6b0
[  373.464003]
stack backtrace:
[  373.464005] CPU: 1 PID: 30 Comm: kworker/1:1 Kdump: loaded Tainted: G           O      4.18.0-rc7uschi+ #123
[  373.464007] Hardware name: IBM 2827 H43 738 (LPAR)
[  373.464010] Workqueue: events smc_listen_work [smc]
[  373.464011] Call Trace:
[  373.464015] ([<0000000000114100>] show_stack+0x60/0xd8)
[  373.464019]  [<0000000000a8c9bc>] dump_stack+0x9c/0xd8
[  373.464021]  [<00000000001dcaf8>] print_unlock_imbalance_bug+0xf8/0x108
[  373.464022]  [<00000000001e045c>] lock_release+0x114/0x4f8
[  373.464025]  [<0000000000aa87fa>] __mutex_unlock_slowpath+0x4a/0x300
[  373.464027]  [<000003ff801205fc>] smc_listen_work+0x22c/0x5d0 [smc]
[  373.464029]  [<0000000000197a68>] process_one_work+0x2a8/0x6b0
[  373.464030]  [<0000000000197ec2>] worker_thread+0x52/0x410
[  373.464033]  [<000000000019fd0e>] kthread+0x15e/0x178
[  373.464035]  [<0000000000aaf58a>] kernel_thread_starter+0x6/0xc
[  373.464052]  [<0000000000aaf584>] kernel_thread_starter+0x0/0xc
[  373.464054] INFO: lockdep is turned off.
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In state SMC_INIT smc_poll() delegates polling to the internal
CLC socket. This means, once the connect worker has finished
its kernel_connect() step, the poll wake-up may occur. This is not
intended. The wake-up should occur from the wake up call in
smc_connect_work() after __smc_connect() has finished.
Thus in state SMC_INIT this patch now calls sock_poll_wait() on the
main SMC socket.
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

All RDMA ULPs should be using rdma_get_gid_attr instead of
ib_query_gid. Convert SMC to use the new API.

In the process correct some confusion with gid_type - if attr->ndev is
!NULL then gid_type can never be IB_GID_TYPE_IB by
definition. IB_GID_TYPE_ROCE shares the same enum value and is probably
what was intended here.
Reviewed-by: NParav Pandit <parav@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

This reverts commit ddb457c6.

The include rdma/ib_cache.h is kept, and we have to add a memset
to the compat wrapper to avoid compiler warnings in gcc-7

This revert is done to avoid extensive merge conflicts with SMC
changes in netdev during the 4.19 merge window.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

With SMC-D z/OS sends a test link signal every 10 seconds. Linux is
supposed to answer, otherwise the SMC-D connection breaks.
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When an SMC socket is connecting it is decided whether fallback to
TCP is needed. To avoid races between connect and ioctl move the
sock lock before the use_fallback check.

Reported-by: syzbot+5b2cece1a8ecb2ca77d8@syzkaller.appspotmail.com
Reported-by: syzbot+19557374321ca3710990@syzkaller.appspotmail.com
Fixes: 1992d998 ("net/smc: take sock lock in smc_ioctl()")
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Without setsockopt SO_SNDBUF and SO_RCVBUF settings, the sysctl
defaults net.ipv4.tcp_wmem and net.ipv4.tcp_rmem should be the base
for the sizes of the SMC sndbuf and rcvbuf. Any TCP buffer size
optimizations for servers should be ignored.
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Invoking shutdown for a socket in state SMC_LISTEN does not make
sense. Nevertheless programs like syzbot fuzzing the kernel may
try to do this. For SMC this means a socket refcounting problem.
This patch makes sure a shutdown call for an SMC socket in state
SMC_LISTEN simply returns with -ENOTCONN.
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If a writer blocked condition is received without data, the current
consumer cursor is immediately sent. Servers could already receive this
condition in state SMC_INIT without finished tx-setup. This patch
avoids sending a consumer cursor update in this case.
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The wait_address argument is always directly derived from the filp
argument, so remove it.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Send an orderly DELETE LINK request before termination of a link group,
add support for client triggered DELETE LINK processing. And send a
disorderly DELETE LINK before module is unloaded.
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Remember the fallback reason code and the peer diagnosis code for
smc sockets, and provide them in smc_diag.c to the netlink interface.
And add more detailed reason codes.
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

SMC code uses the base gid for VLAN traffic. The gids exchanged in
the CLC handshake and the gid index used for the QP have to switch
from the base gid to the appropriate vlan gid.

When searching for a matching IB device port for a certain vlan
device, it does not make sense to return an IB device port, which
is not enabled for the used vlan_id. Add another check whether a
vlan gid exists for a certain IB device port.
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Link confirmation will always be sent across the new link being
confirmed. This allows to shrink the parameter list.
No functional change.
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Instead of declaring and passing a dummy 'bad_wr' pointer, pass NULL
as third argument to ib_post_(send|recv|srq_recv)().
Signed-off-by: NBart Van Assche <bart.vanassche@wdc.com>
Acked-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Remove a WARN_ON() statement that verifies something that is guaranteed
by the RDMA API, namely that the failed_wr pointer is not touched if an
ib_post_send() call succeeds and that it points at the failed wr if an
ib_post_send() call fails.
Signed-off-by: NBart Van Assche <bart.vanassche@wdc.com>
Acked-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

The page map address is already stored in the RMB descriptor.
There is no need to derive it from the cpu_addr value.
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Link group field tokens_used_mask is a bitmap. Use macro
DECLARE_BITMAP for its definition.
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Replace a frequently used construct with a more readable variant,
reducing the code. Also might come handy when we start to support
more than a single per link group.
Signed-off-by: NStefan Raspl <raspl@linux.ibm.com>
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The functions to read and write cursors are exclusively used to copy
cursors. Therefore switch to a respective function instead.
Signed-off-by: NStefan Raspl <raspl@linux.ibm.com>
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Rename field diag_fallback into diag_mode and set the smc mode of a
connection explicitly.
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

During clc handshake the receive timeout is set to CLC_WAIT_TIME.
Remember and reset the original timeout value after the receive calls,
and remove a duplicate assignment of CLC_WAIT_TIME.
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For security reasons the return code of get_user() should always be
checked.

Fixes: 01d2f7e2 ("net/smc: sockopts TCP_NODELAY and TCP_CORK")
Reported-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The SMC protocol requires to send a separate consumer cursor update,
if it cannot be piggybacked to updates of the producer cursor.
Currently the decision to send a separate consumer cursor update
just considers the amount of data already received by the socket
program. It does not consider the amount of data already arrived, but
not yet consumed by the receiver. Basing the decision on the
difference between already confirmed and already arrived data
(instead of difference between already confirmed and already consumed
data), may lead to a somewhat earlier consumer cursor update send in
fast unidirectional traffic scenarios, and thus to better throughput.
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Suggested-by: NThomas Richter <tmricht@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

SMC ioctl processing requires the sock lock to work properly in
all thinkable scenarios.
Problem has been found with RaceFuzzer and fixes:
   KASAN: null-ptr-deref Read in smc_ioctl
Reported-by: NByoungyoung Lee <lifeasageek@gmail.com>
Reported-by: syzbot+35b2c5aa76fd398b9fd4@syzkaller.appspotmail.com
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Reviewed-by: NStefano Brivio <sbrivio@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

smc_release() calls a sock_put() for smc fallback sockets to cover
the passive closing sock_hold() in __smc_connect() and
smc_tcp_listen_work(). This does not make sense for sockets in state
SMC_LISTEN and SMC_INIT.
An SMC socket stays in state SMC_INIT if connect fails. The sock_put
in smc_connect_abort() does not cover all failures. Move it into
smc_connect_decline_fallback().

Fixes: ee9dfbef ("net/smc: handle sockopts forcing fallback")
Reported-by: syzbot+3a0748c8f2f210c0ef9b@syzkaller.appspotmail.com
Reported-by: syzbot+9e60d2428a42049a592a@syzkaller.appspotmail.com
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

My networking merge (commit 4e33d7d4: "Pull networking fixes from
David Miller") got the poll() handling conflict wrong for af_smc.

The conflict between my a11e1d43 ("Revert changes to convert to
->poll_mask() and aio IOCB_CMD_POLL") and Ursula Braun's 24ac3a08
("net/smc: rebuild nonblocking connect") should have left the call to
sock_poll_wait() in place, just without the socket lock release/retake.

And I really should have realized that.  But happily, I at least asked
Ursula to double-check the merge, and she set me right.

This also fixes an incidental whitespace issue nearby that annoyed me
while looking at this.
Pointed-out-by: NUrsula Braun <ubraun@linux.ibm.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch adds diag support for SMC-D.
Signed-off-by: NHans Wippel <hwippel@linux.ibm.com>
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Suggested-by: NThomas Richter <tmricht@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch ties together the previous SMC-D patches. It adds support for
SMC-D to the listen and connect functions and, thus, enables SMC-D
support in the SMC code. If a connection supports both SMC-R and SMC-D,
SMC-D is preferred.
Signed-off-by: NHans Wippel <hwippel@linux.ibm.com>
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Suggested-by: NThomas Richter <tmricht@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The data transfer and CDC message headers differ in SMC-R and SMC-D.
This patch adds support for the SMC-D data transfer to the existing SMC
code. It consists of the following:

* SMC-D CDC support
* SMC-D tx support
* SMC-D rx support

The CDC header is stored at the beginning of the receive buffer. Thus, a
rx_offset variable is added for the CDC header offset within the buffer
(0 for SMC-R).
Signed-off-by: NHans Wippel <hwippel@linux.ibm.com>
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Suggested-by: NThomas Richter <tmricht@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>