OSN devices currently spend an awful long time in qeth_l2_set_online()
until various unsupported HW cmds time out. This has been broken for
over two years, ever since
commit d22ffb5a71 ("s390/qeth: fix IPA command submission race")
triggered a FW bug in cmd processing.
Prior to commit 782e4a7921 ("s390/qeth: don't poll for cmd IO completion"),
this wait for timeout would have even been spent busy-polling.
The offending patch was picked up by stable and all relevant distros,
and yet noone noticed.
OSN setups only ever worked in combination with an out-of-tree blob, and
the last machine that even offered HW with OSN support was released back
in 2015.
Rather than attempting to work-around this FW issue for no actual gain,
add a deprecation warning so anyone who still wants to maintain this
part of the code can speak up. Else rip it all out in 2021.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The last machine generation that supports OSN is z13, and OSX is only
supported up to z14. Allow users and distros to decide whether they
still need support for these device types.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Return the correct errnos when .ndo_set_mac_address fails to set a new
MAC address.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We're down to a single bit flag for MAC-address related status, reflect
that in the info struct.
Also set up the flag during initialization instead of clearing it during
shutdown - one more little step towards unifying the shutdown code.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
To check whether a netdevice has already been registered, look at
NETREG_REGISTERED to replace some hacks I added a while ago.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
qeth_do_ioctl() is only reached through our own net_device_ops, so we
can trust that dev->ml_priv still contains what we put there earlier.
qeth_bridgeport_an_set() is an internal function that doesn't require
such sanity checks.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
z/VM NICs don't offer HW QoS for TX rings. So just use netdev_pick_tx()
to distribute the connections equally over all enabled TX queues.
We start with just 1 enabled TX queue (this matches the typical
configuration without prio-queueing). A follow-on patch will allow users
to enable additional TX queues.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When falling back to an allocation from the HW header cache, check if
the skb is eligible for using memory reserves.
This only makes a difference if the cache is empty and needs to be
refilled.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When qeth's napi poll code fails to refill an entirely empty RX ring, it
kicks off buffer_reclaim_work to try again later.
Make sure that this worker is cancelled when setting the qeth device
offline. Otherwise a RX refill action can unexpectedly end up running
concurrently to bigger re-configurations (eg. resizing the buffer pool),
without any locking.
Fixes: b333293058 ("qeth: add support for af_iucv HiperSockets transport")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
After recent cleanups this is just a complicated wrapper around an u32*.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When getting or setting VNICC parameters, the error code EOPNOTSUPP
should have precedence over EBUSY.
EBUSY is used because vnicc feature and bridgeport feature are mutually
exclusive, which is a temporary condition.
Whereas EOPNOTSUPP indicates that the HW does not support all or parts of
the vnicc feature.
This issue causes the vnicc sysfs params to show 'blocked by bridgeport'
for HW that does not support VNICC at all.
Fixes: caa1f0b10d ("s390/qeth: add VNICC enable/disable support")
Signed-off-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
qeth_l?_stop_card() is _never_ called while in HARDSETUP state, and
there's no other usage of the card state that relies on the
DOWN -> HARDSETUP -> SOFTSETUP transition.
As related cleanup, remove the check in qeth_realloc_buffer_pool() as it
is already done by the callers.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When data is received on the READ channel, the matching logic for cmds
that are waiting for a reply is currently hard-coded into the channel's
main IO callback.
Move this into a per-cmd callback, so that we can apply custom matching
logic for each individual cmd.
This also allows us to remove the coarse-grained check for unexpected
non-IPA replies, since they will no longer match against _all_ pending
cmds.
Note that IDX cmds use _no_ matcher, since their reply is synchronously
received as part of the cmd's IO.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Large parts of the online/offline code are identical now, and cleaning
up the remaining stuff is easier with a shared core.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Move some duplicated logic into a shared code path.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
qeth_l2_setup_bridgeport_attrs() is entirely unrelated to sysfs
functionality, move it where it belongs.
While at it merge all the bridgeport-specific code in the set-online
path together.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
To reduce the path length and levels of indirection, move the RX
processing from the sub-drivers into the core.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
During vnicc_init wanted_char should be compared to cur_char and not
to QETH_VNICC_DEFAULT. Without this patch there is no way to enforce
the default values as desired values.
Note, that it is expected, that a card comes online with default values.
This patch was tested with private card firmware.
Fixes: caa1f0b10d ("s390/qeth: add VNICC enable/disable support")
Signed-off-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Symptom: After vnicc/rx_bcast has been manually set to 0,
bridge_* sysfs parameters can still be set or written.
Only occurs on HiperSockets, as OSA doesn't support changing rx_bcast.
Vnic characteristics and bridgeport settings are mutually exclusive.
rx_bcast defaults to 1, so manually setting it to 0 should disable
bridge_* parameters.
Instead it makes sense here to check the supported mask. If the card
does not support vnicc at all, bridge commands are always allowed.
Fixes: caa1f0b10d ("s390/qeth: add VNICC enable/disable support")
Signed-off-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Symptom: Error message "Configuring the VNIC characteristics failed"
in dmesg whenever an OSA interface on z15 is set online.
The VNIC characteristics get re-programmed when setting a L2 device
online. This follows the selected 'wanted' characteristics - with the
exception that the INVISIBLE characteristic unconditionally gets
switched off.
For devices that don't support INVISIBLE (ie. OSA), the resulting
IO failure raises a noisy error message
("Configuring the VNIC characteristics failed").
For IQD, INVISIBLE is off by default anyways.
So don't unnecessarily special-case the INVISIBLE characteristic, and
thereby suppress the misleading error message on OSA devices.
Fixes: caa1f0b10d ("s390/qeth: add VNICC enable/disable support")
Signed-off-by: Alexandra Winter <wintera@linux.ibm.com>
Reviewed-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
qeth_l?_set_online() goes through a number of initialization steps, and
on any error uses qeth_l?_stop_card() to tear down the residual state.
The first initialization step is qeth_core_hardsetup_card(). When this
fails after having established a QDIO context on the device
(ie. somewhere after qeth_mpc_initialize()), qeth_l?_stop_card() doesn't
shut down this QDIO context again (since the card state hasn't
progressed from DOWN at this stage).
Even worse, we then call qdio_free() as final teardown step to free the
QDIO data structures - while some of them are still hooked into wider
QDIO infrastructure such as the IRQ list. This is inevitably followed by
use-after-frees and other nastyness.
Fix this by unconditionally calling qeth_qdio_clear_card() to shut down
the QDIO context, and also to halt/clear any pending activity on the
various IO channels.
Remove the naive attempt at handling the teardown in
qeth_mpc_initialize(), it clearly doesn't suffice and we're handling it
properly now in the wider teardown code.
Fixes: 4a71df5004 ("qeth: new qeth device driver")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When managing the promiscuous mode during an RX modeset, qeth caches the
current HW state to avoid repeated programming of the same state on each
modeset.
But while tearing down a device, we forget to clear the cached state. So
when the device is later set online again, the initial RX modeset
doesn't program the promiscuous mode since we believe it is already
enabled.
Fix this by clearing the cached state in the tear-down path.
Note that for the SBP variant of promiscuous mode, this accidentally
works right now because we unconditionally restore the SBP role while
re-initializing.
Fixes: 4a71df5004 ("qeth: new qeth device driver")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The cio layer's intparm logic does not align itself well with how qeth
manages cmd IOs. When an active IO gets terminated via halt/clear, the
corresponding IRQ's intparm does not reflect the cmd buffer but rather
the intparm that was passed to ccw_device_halt() / ccw_device_clear().
This behaviour was recently clarified in
commit b91d9e67e5 ("s390/cio: fix intparm documentation").
As a result, qeth_irq() currently doesn't cancel a cmd that was
terminated via halt/clear. This primarily causes us to leak
card->read_cmd after the qeth device is removed, since our IO path still
holds a refcount for this cmd.
For qeth this means that we need to keep track of which IO is pending on
a device ('active_cmd'), and use this as the intparm when calling
halt/clear. Otherwise qeth_irq() can't match the subsequent IRQ to its
cmd buffer.
Since we now keep track of the _expected_ intparm, we can also detect
any mismatch; this would constitute a bug somewhere in the lower layers.
In this case cancel the active cmd - we effectively "lost" the IRQ and
should not expect any further notification for this IO.
Fixes: 405548959c ("s390/qeth: add support for dynamically allocated cmds")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Minor conflict in drivers/s390/net/qeth_l2_main.c, kept the lock
from commit c8183f5489 ("s390/qeth: fix potential deadlock on
workqueue flush"), removed the code which was removed by commit
9897d583b0 ("s390/qeth: consolidate some duplicated HW cmd code").
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
The L2 bridgeport code uses the coarse 'conf_mutex' for guarding access
to its configuration state.
This can result in a deadlock when qeth_l2_stop_card() - called under the
conf_mutex - blocks on flush_workqueue() to wait for the completion of
pending bridgeport workers. Such workers would also need to aquire
the conf_mutex, stalling indefinitely.
Introduce a lock that specifically guards the bridgeport configuration,
so that the workers no longer need the conf_mutex.
Wrapping qeth_l2_promisc_to_bridge() in this fine-grained lock then also
fixes a theoretical race against a concurrent qeth_bridge_port_role_store()
operation.
Fixes: c0a2e4d10d ("s390/qeth: conclude all event processing before offlining a card")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Packets with an unexpected HW format are currently first extracted from
the RX buffer, passed upwards to the layer-specific driver and only then
finally dropped.
Enhance the RX path so that we can drop such packets before even
allocating an skb. For this, add some additional logic so that when a
packet is meant to be dropped, we can still walk along the packet's data
chunks in the RX buffer. This allows us to extract the following
packet(s) from the buffer.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Where available, use the fine-grained counters in rtnl_link_stats64 to
indicate different RX error causes. For drop reasons, use driver-private
ethtool counters.
In particular this patch allows us to keep track of driver-side drops due
to unknown/unsupported HW descriptor format.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When setting a device online, both subdrivers have the same code to
program the HW trap and Isolation mode. Move that code into a single
place.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Without this patch, a command bit in the supported commands mask is only
ever set to unsupported during set online. If a command is ever marked as
unsupported (e.g. because of error during qeth_l2_vnicc_query_cmds),
subsequent successful initialization (offline/online) would not bring it
back.
Fixes: caa1f0b10d ("s390/qeth: add VNICC enable/disable support")
Signed-off-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Smatch discovered the use of uninitialized variable sup_cmds
in error paths.
Fixes: caa1f0b10d ("s390/qeth: add VNICC enable/disable support")
Signed-off-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
This consolidates the SW statistics code, and improves it to
(1) account for the header overhead of each segment on a TSO skb,
(2) count dangling packets as in-error (during eg. shutdown), and
(3) only count offloads when the skb was successfully transmitted.
We also count each segment of an TSO skb as one packet - except for
tx_dropped, to be consistent with dev->tx_dropped.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We have logic to determine the desired promisc mode in _each_ code path.
Change things around so that there is a clean split between
(a) high-level code that selects the new mode, and (b) implementations
of the various mechanisms to program this mode.
This also keeps qeth_promisc_to_bridge() from polluting the debug logs
on each RX modeset.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When processing the reply for a vnicc cmd, there's no need to remember
which specific sub-cmd type we initially sent. The reply itself contains
all the needed information.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Except for card->read_cmd, every cmd we issue now passes through
qeth_send_control_data() and allocates a qeth_reply struct. The way we
use this struct requires additional refcounting, and pointer tracking.
Clean up things by moving most of qeth_reply's content into the main
cmd struct. This keeps things in one place, saves us the additional
refcounting and simplifies the overall code flow.
A nice little benefit is that we can now match incoming replies against
the pending requests themselves, without caching the requests' seqnos.
The qeth_reply struct stays around for a little bit longer in a shrunk
form, to avoid touching every single callback.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When an cmd IO completes in qeth_irq(), calculate how much data was
processed by the device and pass this value to the cmd's callback.
This allows cmds that retrieve data from the device to check whether
sufficient data was received, so we do that in qeth_read_conf_data_cb().
Suggested-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Mark switch cases where we are expecting to fall through.
This patch fixes the following warnings (Building: s390):
drivers/s390/net/ctcm_fsms.c: In function ‘ctcmpc_chx_attnbusy’:
drivers/s390/net/ctcm_fsms.c:1703:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (grp->changed_side == 1) {
^
drivers/s390/net/ctcm_fsms.c:1707:2: note: here
case MPCG_STATE_XID0IOWAIX:
^~~~
drivers/s390/net/ctcm_mpc.c: In function ‘ctc_mpc_alloc_channel’:
drivers/s390/net/ctcm_mpc.c:358:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (callback)
^
drivers/s390/net/ctcm_mpc.c:360:2: note: here
case MPCG_STATE_XID0IOWAIT:
^~~~
drivers/s390/net/ctcm_mpc.c: In function ‘mpc_action_timeout’:
drivers/s390/net/ctcm_mpc.c:1469:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if ((fsm_getstate(rch->fsm) == CH_XID0_PENDING) &&
^
drivers/s390/net/ctcm_mpc.c:1472:2: note: here
default:
^~~~~~~
drivers/s390/net/ctcm_mpc.c: In function ‘mpc_send_qllc_discontact’:
drivers/s390/net/ctcm_mpc.c:2087:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (grp->estconnfunc) {
^
drivers/s390/net/ctcm_mpc.c:2092:2: note: here
case MPCG_STATE_FLOWC:
^~~~
drivers/s390/net/qeth_l2_main.c: In function ‘qeth_l2_process_inbound_buffer’:
drivers/s390/net/qeth_l2_main.c:328:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (IS_OSN(card)) {
^
drivers/s390/net/qeth_l2_main.c:337:3: note: here
default:
^~~~~~~
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The cast type currently gets selected in .ndo_start_xmit, and is then
piped through several layers until it's stored into the HW header.
Push the selection down into qeth_l?_fill_header() to (1) reduce the
number of xmit-wide parameters, and (2) merge the two route validation
checks into just one.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
De-duplicate the pm callback implementations from the two sub-drivers,
replacing them with core helpers that delegate to the .set_online and
.set_offline callbacks.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Now that all cmds are dynamically allocated, the code for static cmd
buffers can go away entirely. Resulting in a nice reduction of
code/data size & complexity, while removing the risk that
qeth_clear_cmd_buffers() releases cmds that are still in-flight.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The VNICC code is somewhat quirky in that it defers the whole cmd setup
to a common helper qeth_l2_vnicc_request(). Some of the cmd specifics
are then passed in via parameter, while others are simply hard-coded.
Split the whole machinery up into the usual format: one helper that
allocates the cmd & fills in the common fields, while all the cmd
originators take care of their sub-cmd type specific work.
This makes it much easier to calculate the cmd's precise length, and
reduces code complexity.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch converts the adapter, assist and bridgeport cmd paths to
dynamic allocation. Most of the work is about re-organizing the cmd
headers, calculating the correct cmd length, and filling in the right
value in the sub-cmd's length field.
Since we now also set the correct length for cmds that are not reflected
by a fixed struct (ie SNMP), we can remove the work-around from
qeth_snmp_command().
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch reduces the usage of the write channel's static cmd buffers,
by dynamically allocating all simple IPA cmds (eg. STARTLAN, SETVMAC).
It also converts the OSN path.
Doing so requires some changes to how we calculate the cmd length.
Currently when building IPA cmds, we're quite generous in how much data
we send down to the device (basically the size of the biggest cmd we
know). This is no real concern at the moment, since the static cmd
buffers are backed with zeroed pages. But for dynamic allocations, the
exact length matters. So this patch also adds the needed length
calculations to each cmd path.
Commands that have multiple subtypes (eg. SETADP) of differing length
will be converted with follow-up patches.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We statically allocate 8 cmd buffers on the read channel, when the only
IO left that's still using them is the long-running READ.
Replace this with a single allocated cmd, that gets restarted whenever
the READ completed.
This introduces refcounting for allocated cmds, so that the READ cmd can
survive the IO completion.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Each cmd buffer maintains a pointer to the IO channel that it was/will
be issued on. So when dealing with cmd buffers, we don't need to pass
around a separate channel pointer.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The vast majority of SETUP-classified trace entries can be moved to
their device-specific trace file. This reduces pollution of the global
SETUP file, and provides a consistent trace view of all activity on the
device.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
OSN currently provides a custom code path to submit IPA cmds, without
waiting for the cmd response. Replace it with qeth_send_ipa_cmd(), which
uses the common qeth_send_control_data() IO infrastructure.
By setting a custom iob->callback, we can now provide feedback to the
caller about whether the cmd has been successfully submitted to HW.
Since the callback then immediately wakes up the reply-waiter object, we
maintain the old behaviour of returning early without waiting for the
response.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The basic MPC initialization sequence is strictly sequential, and
waiting for an available cmd buffer should never be necessary.
So this change only affects the OSN path, where dangling waiters on an
unbounded wait_event() are not desirable. Switch to qeth_get_buffers(),
and let OSN callers deal with -ENOMEM.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When the tear down sequence in qeth_l?_stop_card() has finished, the
card is guaranteed to be in DOWN state and we don't have to check for
it again.
With this insight we can also remove the redundant setting of
card->state in qeth_l?_set_online()'s error path.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
