The iser disconnection flow isn't done before all the inflight
recv/send buffers posted to the QP are either flushed or normally
completed to the CQ that serves this connection.  The condition check
is done in iser_handle_comp_error().

Currently, it's possible for the send buffer completion that makes the
posted send buffers counter reach zero to be polled in the drain tx
call, which is after the rx cq is fully drained.  Since this
completion might be not an error one (for example, it might be a
completion of the logout request iSCSI PDU) we will skip
iser_handle_comp_error().  So the connection will never terminate from
the iscsi stack point of view, and we hang.

To resolve this race, do the draining of the tx cq before the loop on
the rx cq.
Signed-off-by: NRoi Dayan <roid@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Fix pr_err (printk) format warning:

    drivers/infiniband/ulp/iser/iser_verbs.c:1181:4: warning: format '%lx' expects argument of type 'long unsigned int', but argument 3 has type 'sector_t' [-Wformat]
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

After allocating a scsi_host we set protection types and guard type
supported.
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NAlex Tabachnik <alext@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Once the iSCSI transaction is completed we must implement
check_protection in order to notify on DIF errors that may have
occured.

The routine boils down to calling ib_check_mr_status to get the
signature status of the transaction.
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NAlex Tabachnik <alext@mellanox.com>
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Add logic to initialize protection information entities.  Upon each
iSCSI task, we keep the scsi_cmnd in order to query the scsi
protection operations and reference to protection buffers.

Modify iser_fast_reg_mr to receive indication whether it is
registering the data or protection buffers.

In addition introduce iser_reg_sig_mr which performs fast registration
work-request for a signature enabled memory region
(IB_WR_REG_SIG_MR).  In this routine we set all the protection
relevants for the device to offload protection data-transfer and
verification.
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NAlex Tabachnik <alext@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

During connection establishment we also initialize T10-PI resources
(QP, PI contexts) in order to support SCSI's protection operations.
Signed-off-by: NAlex Tabachnik <alext@mellanox.com>
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Use modparams to activate protection information support.

pi_enable bool: Based on this parameter iSER will know if it should
support T10-PI.  We don't want to do this by default as it requires to
allocate and initialize extra resources.  In case pi_enable=N, iSER
won't publish to SCSI midlayer any DIF capabilities.

pi_guard int: Based on this parameter iSER will publish DIX guard type
support to SCSI midlayer.  0 means CRC is allowed to be passed in DIX
buffers, 1 (or non-zero) means IP-CSUM is allowed to be passed in DIX
buffers.  Note that over the wire, only CRC is allowed.

In the next phase, it is worth considering passing these parameters
from iscsid via nlmsg.  This will allow these parameters to be
connection based rather than global.
Signed-off-by: NAlex Tabachnik <alext@mellanox.com>
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Unaligned SG-lists may also happen for protection information.
Generalize bounce buffer routine to handle any iser_data_buf which may
be data and/or protection.

This patch does not change any functionality.
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

This routines operates on data buffers and may also work with
protection infomation buffers.  So we generalize them to handle an
iser_data_buf which can be the command data or command protection
information.

This patch does not change any functionality.
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

In T10-PI support we will have memory keys for protection buffers and
signature transactions.  We prefer to compact indicators rather than
keeping multiple bools.

This commit does not change any functionality.
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NAlex Tabachnik <alext@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

For T10-PI offload support, we will need to know the device signature
offload capability upon every connection establishment.

This patch does not change any functionality.
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NAlex Tabachnik <alext@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

fastreg descriptor will include protection information context.  In
order to place the logic in one place we introduce iser_create_fr_desc
function.

This patch does not change any functionality.
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NAlex Tabachnik <alext@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

This is a preparation step for T10-PI offload support.  We prefer to
push the desicion of which mkey to use (global or fastreg) to
iser_fast_reg_mr.  We choose to do this since in T10-PI we may need to
register for protection buffers and in this case we wish to simplify
iser_fast_reg_mr instead of repeating the logic of which key to use.

This patch does not change any functionality.
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NAlex Tabachnik <alext@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

FRWR stands for "fast registration work request". We want to avoid
calling the fastreg pool with that name, instead we name it fastreg
which stands for "fast registration".

This pool will include more elements in the future, so it is a good
idea to generalize the name.
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NAlex Tabachnik <alext@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

In case iSER uses fast registration method, it should not request for
successful completions on fast registration nor local invalidate
requests.  We color wr_id with ISER_FRWR_LI_WRID in order to correctly
consume error completions.
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

We use "tx_desc" again after we free it.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Acked-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Fix a possible NULL pointer dereference in disconnection flow. This
can happen if the target disconnected/rejected the connection request,
e.g before the binding stage between iscsi connection to the transport
connection.
Signed-off-by: NAlex Tabachnik <alext@mellanox.com>
Signed-off-by: NRoi Dayan <roid@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

This bug was discovered by Smatch static checker run by Dan Carpenter.
If in free_rx_descriptors(), rx_descs are not NULL then the iser
device is definately not NULL, so no need to check it before
dereferencing it.
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Fix leak where desc is not being freed in error flows.
Signed-off-by: NRoi Dayan <roid@mellanox.com>
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

To run discovery over iSER we need to advertize the CAP_TEXT_NEGO capability
towards user space. Also need to make sure the login RX buffer is posted when
SendTargets TEXT PDUs are sent. For that end, we use a setting of the
ISCSI_PARAM_DISCOVERY_SESS iscsi param as an indication that this is
discovery session.
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Newer HCAs and Virtual functions may not support FMRs but rather a fast
registration model, which we call FRWR - "Fast Registration Work Requests".

This model was introduced in 00f7ec36 ("RDMA/core: Add memory management
extensions support") and works when the IB device supports the
IB_DEVICE_MEM_MGT_EXTENSIONS capability.

Upon creating the iser device iser will test whether the HCA supports
FMRs.  If no support for FMRs, check if IB_DEVICE_MEM_MGT_EXTENSIONS
is supported and assign function pointers that handle fast
registration and allocation of appropriate resources (fast_reg
descriptors).

Registration is done using posting IB_WR_FAST_REG_MR to the QP and
invalidations using posting IB_WR_LOCAL_INV.
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

This is preparation step for other memory registration methods to be
added.  In addition, change reg/unreg routines signature to indicate
they use FMRs.
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

This routine will be shared with other rdma management schemes.  The
bounce buffer solution for unaligned SG-lists and the sg_to_page_vec
routine are likely to be used for other registration schemes and not
just FMR.

Move them out of the FMR specific code, and call them from there.
Later they will be called also from other reg methods code.
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Currently the driver uses FMRs as the only means to register the
memory pointed by SG provided by the SCSI mid-layer with the RDMA
device.

As preparation step for adding more methods for fast path memory
registration, make the alloc/free and reg/unreg calls function
pointers, which are for now just set to the existing FMR ones.
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Use cmds_max passed from user space to be the number of PDUs to be
supported for the session instead of hard-coded ISCSI_DEF_XMIT_CMDS_MAX.
This allow controlling the max number of SCSI commands for the session.
Also don't ignore the qdepth passed from user space.

Derive from session->cmds_max the actual number of RX buffers and FMR
pool size to allocate during the connection bind phase.

Since the iser transport connection is established before the iscsi
session/connection are created and bound, we still use one hard-coded
quantity ISER_DEF_XMIT_CMDS_MAX to compute the maximum number of
work-requests to be supported by the RC QP used for the connection.

The above quantity is made to be a power of two between ISCSI_TOTAL_CMDS_MIN
(16) and ISER_DEF_XMIT_CMDS_MAX (512) inclusive.
Signed-off-by: NShlomo Pongratz <shlomop@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

This is a preparation step to a patch that accepts the number of max
SCSI commands to be supported a session from user space iSCSI tools.

Move the allocation of the login buffer, FMR pool and its associated
page vector from iser_create_ib_conn_res() (which is called prior when
we actually know how many commands should be supported) to
iser_alloc_rx_descriptors() (which is called during the iscsi
connection bind step where this quantity is known).

Also do small refactoring around the deallocation to make that path
similar to the allocation one.
Signed-off-by: NShlomo Pongratz <shlomop@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Commit 4f363882 ("IB/iser: Move informational messages from error
to info level") set info prints to be emitted at a lower debug level
than warning prints, which is a bit odd.  Fix that.

Also move the prints on unaligned SG from warning to debug level.
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Add Mellanox copyright to the iser initiator source code which I maintain.
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Change the code to destroy the "last opened" rdma_cm id after making
sure we released all other objects (QP, CQs, PD, etc) associated with
the IB device.

Since iser accesses the IB device using the rdma_cm id, we need to
free any objects that are related to the device that is associated
with the rdma_cm id prior to destroying that id.  When this isn't
done, the low level driver that created this device can be unloaded
before iser has a chance to free all the objects and a such a call may
invoke code segment which isn't valid any more and crash.

Cc: Sean Hefty <sean.hefty@intel.com
Signed-off-by: NRoi Dayan <roid@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Annex A12 of the IBTA spec defines additional information that needs
to be provided through the CM exchange relating to usage of ZBVA (Zero
Based VAs) and Send With Invalidate over an iSER connection.

Currently, the initiator sets both to not supported, but does provide
the header so that existing iSER targets can be patched to start
looking on the private data carried by the CM.

This is a preparation step to enable iSER with HW drivers for which
FMRs are not supported, such as mlx4 VF instances or new HW devices
which might support only FRWR (Fast Registration Work-Requests) along
the details of the IB_DEVICE_MEM_MGT_EXTENSIONS device capability.
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Commit 819a0873 ("IB/iser: Avoid error prints on EAGAIN
registration failures") not only eliminated the error print on that
case, but rather also modified the code such that it doesn't return
any error to upper layers.  As a result a wrong mapping was used.  Fix
this to correctly return the error in that case.
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Introduce iser_info() and move informational messages that were
printed as errors to use that macro. Also, cleanup printk leftovers to
use the existing macros.
Signed-off-by: NRoi Dayan <roid@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>

[ Use pr_warn(... instead of printk(KERN_WARNING ....  - Roland ]
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Add displaying module version, update the version to 1.1,
and remove the DRV_DATE define.
Signed-off-by: NRoi Dayan <roid@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Reuse the "SG unaligned for FMR" driver flow to make the initiator
functional when running over driver instance which doesn't support
FMRs, such as a mlx4 virtual function.
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NAlex Tabachnik <alext@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Under IO/CPU stress its possible that the FMR pool might not have a
free FMR mapping element for iSER to use because of incomplete
background unmapping processing.  In that case we get -EAGAIN and the
IO is pushed back to the SCSI layer which soon retries it.  No need to
be so verbose about that.
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

ISER_DEF_CMD_PER_LUN was meant to be ISCSI_DEF_XMIT_CMDS_MAX, not plain 128
Signed-off-by: NRoi Dayan <roid@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

RX/TX CQs will now be selected from a per HCA pool.  For the RX flow
this has the effect of using different interrupt vectors when using
low level drivers (such as mlx4) that map the "vector" param provided
by the ULP on CQ creation to a dedicated IRQ/MSI-X vector.  This
allows the RX flow processing of IO responses to be distributed across
multiple CPUs.

QPs (--> iSER sessions) are assigned to CQs in round robin order using
the CQ with the minimum number of sessions attached to it.
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NAlex Tabachnik <alext@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

The current error flow code was releasing the IB connection object and
calling iscsi_destroy_endpoint() directly without going through the
reference counting mechanism introduced in commit 39ff05db ("IB/iser:
Enhance disconnection logic for multi-pathing"). This resulted in a
double free of the iscsi endpoint object, which causes a kernel NULL
pointer dereference.  Fix that by plugging into the IB conn reference
counting correctly.
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Acked-by: NRoland Dreier <roland@purestorage.com>
Signed-off-by: NCong Wang <amwang@redhat.com>

An iser target may send iscsi NO-OP PDUs as soon as it marks the iSER
iSCSI session as fully operative.  This means that there is window
where there are no posted receive buffers on the initiator side, so
it's possible for the iSER RC connection to break because of RNR NAK /
retry errors.  To fix this, rely on the flags bits in the login
request to have FFP (0x3) in the lower nibble as a marker for the
final login request, and post an initial chunk of receive buffers
before sending that login request instead of after getting the login
response.
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NRoland Dreier <roland@purestorage.com>