Before a link can be reused it must have been cleared. Lowest current
link state is INACTIVE, which does not mean that the link is already
cleared.
Add a new state UNUSED that is set when the link is cleared and can be
reused.
Add helper smc_llc_usable_link() to find an active link in a link group,
and smc_link_usable() to determine if a link is usable.
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Extend smc_rmb_rtoken_handling() and smc_rtoken_delete() to support
multiple links.
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As a preparation for the support of multiple links remove the usage of
a static link id (SMC_SINGLE_LINK) and allow dynamic link ids.
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As a preparation for the support of multiple links remove the usage of
a static link id (SMC_SINGLE_LINK) and allow dynamic link ids.
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The link_id is the index of the link in the array of the link group.
When a link in the array is reused for a new link, a different unique
link_id should be used, otherwise the index in the array could collide
with the previous link at this array position.
Use a new variable link_idx as array index, and make link_id an
increasing unique id value.
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Move the initialization of a new link into its own function, separate
from smc_lgr_create, to allow more than one link per link group.
Do an extra check if the IB device initialization was successful, and
reset the link state if any error occurs during smcr_link_init().
And rename two existing functions to use the prefix smcr_ to indicate
that they belong to the SMC-R code path.
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If an SMC connection to a certain peer is setup the first time,
a new linkgroup is created. In case of setup failures, such a
linkgroup is unusable and should disappear. As a first step the
linkgroup is removed from the linkgroup list in smc_lgr_forget().

There are 2 problems:
smc_listen_decline() might be called before linkgroup creation
resulting in a crash due to calling smc_lgr_forget() with
parameter NULL.
If a setup failure occurs after linkgroup creation, the connection
is never unregistered from the linkgroup, preventing linkgroup
freeing.

This patch introduces an enhanced smc_lgr_cleanup_early() function
which
* contains a linkgroup check for early smc_listen_decline()
  invocations
* invokes smc_conn_free() to guarantee unregistering of the
  connection.
* schedules fast linkgroup removal of the unusable linkgroup

And the unused function smcd_conn_free() is removed from smc_core.h.

Fixes: 3b2dec26 ("net/smc: restructure client and server code in af_smc")
Fixes: 2a0674ff ("net/smc: improve abnormal termination of link groups")
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

smc_lgr_terminate() and smc_lgr_terminate_sched() both result in soft
link termination, smc_lgr_terminate_sched() is scheduling a worker for
this task. Take out complexity by always using the termination worker
and getting rid of smc_lgr_terminate() completely.
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>

The soft parameter of smc_lgr_terminate() is not used and obsolete.
Remove it.
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>

When 2 callers call smc_lgr_terminate() at the same time
for the same lgr, one gets the lgr_lock and deletes the lgr from the
list and releases the lock. Then the second caller gets the lock and
tries to delete it again.
In smc_lgr_terminate() add a check if the link group lgr is already
deleted from the link group list and prevent to try to delete it a
second time.
And add a check if the lgr is marked as freeing, which means that a
termination is already pending.
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_lgr_cleanup() is called during termination processing, there is no
need to send a DELETE_LINK at that time. A DELETE_LINK should have been
sent before the termination is initiated, if needed.
And remove the extra call to wake_up(&lnk->wr_reg_wait) because
smc_llc_link_inactive() already calls the related helper function
smc_wr_wakeup_reg_wait().
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 reboot_event handler, unregister the ib devices and enable
the IB layer to release the devices before the reboot.

Fixes: a33a803c ("net/smc: guarantee removal of link groups in reboot")
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Save a line of code by making use of ATOMIC_INIT() for lgr_cnt.
Suggested-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>

When rebooting it should be guaranteed all link groups are cleaned
up and freed.
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If the smc module is unloaded return control from exit routine only,
if all link groups are freed.
If an IB device is thrown away return control from device removal only,
if all link groups belonging to this device are freed.
Counters for the total number of SMCR link groups and for the total
number of SMCR links per IB device are introduced. smc module unloading
continues only if the total number of SMCR link groups is zero. IB device
removal continues only it the total number of SMCR links per IB device
has decreased to zero.
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If the SMC module is unloaded or an IB device is thrown away, the
immediate link group freeing introduced for SMCD is exploited for SMCR
as well. That means SMCR-specifics are added to smc_conn_kill().
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Make sure all pending work requests are completed before freeing
a link.
Dismiss tx pending slots already when terminating a link group to
exploit termination shortcut in tx completion queue handler.

And kill the completion queue tasklets after destroy of the
completion queues, otherwise there is a time window for another
tasklet schedule of an already killed tasklet.
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For abnormal termination issue an LLC DELETE_LINK without the
orderly flag.
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If the ism module is unloaded return control from exit routine only,
if all link groups are freed.
If an IB device is thrown away return control from device removal only,
if all link groups belonging to this device are freed.
A counters for the total number of SMCD link groups per ISM device is
introduced. ism module unloading continues only if the total number of
SMCD link groups for all ISM devices is zero. ISM device
removal continues only it the total number of SMCD link groups per ISM
device has decreased to zero.
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

A final cleanup due to SMCD device removal means immediate freeing
of all link groups belonging to this device in interrupt context.

This patch introduces a separate SMCD link group termination routine,
which terminates all link groups of an SMCD device.

This new routine smcd_terminate_all ()is reused if the smc module is
unloaded.
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

SMCD link group termination is called when peer signals its shutdown
of its corresponding link group. For regular shutdowns no connections
exist anymore. For abnormal shutdowns connections must be killed and
their DMBs must be unregistered immediately. That means the SMCR method
to delay the link group freeing several seconds does not fit.

This patch adds immediate termination of a link group and its SMCD
connections and makes sure all SMCD link group related cleanup steps
are finished.
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If peer announces shutdown, use the link group terminate worker for
local cleanup of link groups and connections to terminate link group
in proper context.

Make sure link groups are cleaned up first before destroying the
event queue of the SMCD device, because link group cleanup may
raise events.

Send signal shutdown only if peer has not done it already.

Send socket abort or close only, if peer has not already announced
shutdown.
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch removes variables and callback these are related to the nested
device structure.
devices that can be nested have their own nest_level variable that
represents the depth of nested devices.
In the previous patch, new {lower/upper}_level variables are added and
they replace old private nest_level variable.
So, this patch removes all 'nest_level' variables.

In order to avoid lockdep warning, ->ndo_get_lock_subclass() was added
to get lockdep subclass value, which is actually lower nested depth value.
But now, they use the dynamic lockdep key to avoid lockdep warning instead
of the subclass.
So, this patch removes ->ndo_get_lock_subclass() callback.
Signed-off-by: NTaehee Yoo <ap420073@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With the introduction of the link group termination worker there is
no longer a need to postpone smc_close_active_abort() to a worker.
To protect socket destruction due to normal and abnormal socket
closing, the socket refcount is increased.
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>

Use a worker for link group termination to guarantee process context.
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>

If a link group and its connections must be terminated,
* wake up socket waiters
* do not enable buffer reuse

A linkgroup might be terminated while normal connection closing
is running. Avoid buffer reuse and its related LLC DELETE RKEY
call, if linkgroup termination has started. And use the earliest
indication of linkgroup termination possible, namely the removal
from the linkgroup list.
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>

There are lots of link group termination scenarios. Most of them
still allow to inform the peer of the terminating sockets about aborting.
This patch tries to call smc_close_abort() for terminating sockets.

And the internal TCP socket is reset with tcp_abort().
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>

Usually link groups are freed delayed to enable quick connection
creation for a follow-on SMC socket. Terminated link groups are
freed faster. This patch makes sure, fast schedule of link group
freeing is not rescheduled by a delayed schedule. And it makes sure
link group freeing is not rescheduled, if the real freeing is already
running.
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>

Locking hierarchy requires that the link group conns_lock can be
taken if the socket lock is held, but not vice versa. Nevertheless
socket termination during abnormal link group termination should
be protected by the socket lock.
This patch reduces the time segments the link group conns_lock is
held to enable usage of lock_sock in smc_lgr_terminate().
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>

When a link group is to be terminated, it is sufficient to hold
the lgr lock when unlinking the link group from its list.
Move the lock-protected link group unlinking into smc_lgr_terminate().
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>

The resources for a terminated socket are being cleaned up.
This patch makes sure
* no more data is received for an actively terminated socket
* no more data is sent for an actively or passively terminated socket
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>

If creation of an SMCD link group with VLAN id fails, the initial
smc_ism_get_vlan() step has to be reverted as well.

Fixes: c6ba7c9b ("net/smc: add base infrastructure for SMC-D and ISM")
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>

Add a "going_away" indication to ISM devices and IB ports and
avoid creation of new connections on such disappearing devices.

And do not handle ISM events if ISM device is disappearing.
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>

SMCD link groups belong to certain ISM-devices and SMCR link group
links belong to certain IB-devices. Increase the refcount for
these devices, as long as corresponding link groups exist.
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>

This patch introduces separate locks for the split SMCD and SMCR
link group lists.
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>

Currently SMCD and SMCR link groups are maintained in one list.
To facilitate abnormal termination handling they are split into
a separate list for SMCR link groups and separate lists for SMCD
link groups per SMCD device.
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>

After smc_lgr_create(), the newly created link group is added
to smc_lgr_list, thus is accessible from other context.
Although link group creation is serialized by
smc_create_lgr_pending, the new link group may still be accessed
concurrently. For example, if ib_device is no longer active,
smc_ib_port_event_work() will call smc_port_terminate(), which
in turn will call __smc_lgr_terminate() on every link group of
this device. So conns_lock is required here.
Signed-off-by: NHuaping Zhou <zhp@smail.nju.edu.cn>
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Rework smc_conn_create() to always return a valid DECLINE reason code.
This removes the need to translate the return codes on 4 different
places and allows to easily add more detailed return codes by changing
smc_conn_create() only.
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>

The vlan_id of the underlying CLC socket was retrieved two times
during processing of the listen handshaking. Change this to get the
vlan id one time in connect and in listen processing, and reuse the id.
And add a new CLC DECLINE return code for the case when the retrieval
of the vlan id failed.
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 initialization of an SMC socket a lot of function parameters need
to get passed down the function call path. Consolidate the parameters
in a helper struct so there are less enough parameters to get all passed
by register.
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>