Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

No need to keep lkey, va, len variables, we can keep
them as struct ib_sge. This will help when we change the
memory registration logic.

This patch does not change any functionality.
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NAdir Lev <adirl@mellanox.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Instead of open-coding connection fastreg pool get/put,
we introduce iser_reg_desc[get|put] helpers.

We aren't setting these static as this will be a per-device
routine later on. Also, cleanup iser_unreg_rdma_mem_fastreg
a bit.

This patch does not change any functionality.
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NAdir Lev <adirl@mellanox.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

This struct members other than struct iser_mem_reg are unused,
so remove it altogether.

This patch does not change any functionality.
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NAdir Lev <adirl@mellanox.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

As memory registration/de-registration methods, lets
move them to their natural location. While we're at it,
make iser_reg_page_vec routine static.

This patch does not change any functionality.
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

No need to keep two iser_data_buf structures just in case we use
mem copy. We can avoid that just by adding a pointer to the original
sg. So keep only two iser_data_buf per command (data and protection)
and pass the relevant data_buf to bounce buffer routine.

This patch does not change any functionality.
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NAdir Lev <adirl@mellanox.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

We always unmap SGs with the same direction instead of unmapping
with the direction the mapping was done, fix that.

Fixes: 9a8b08fa ("IB/iser: Generalize iser_unmap_task_data and [...]")
Signed-off-by: NRoi Dayan <roid@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

And fix a checkpatch warning.
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

No reason to settle with four, can use the min between device max comp
vectors and number of cores.
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

It is enough to check mem_h pointer assignment, mem_h == NULL will
indicate that buffer is not registered using mr.
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 a regression was introduced in commit 6df5a128 ("IB/iser:
Suppress scsi command send completions").

The sig_count was wrongly set to be static variable, thus it is
possible that we won't reach to (sig_count % ISER_SIGNAL_BATCH) == 0
condition (due to races) and the send queue will be overflowed.

Instead keep sig_count per connection. We don't need it to be atomic
as we are safe under the iscsi session frwd_lock taken by libiscsi on
the queuecommand path.

Fixes: 6df5a128 ("IB/iser: Suppress scsi command send completions")
Signed-off-by: NMax Gurtovoy <maxg@mellanox.com>
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Re-adjust max CQEs per CQ and max send_wr per QP according
to the resource limits supported by underlying hardware.
Signed-off-by: NMinh Tran <minhduc.tran@emulex.com>
Signed-off-by: NJayamohan Kallickal <jayamohan.kallickal@emulex.com>
Acked-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Update the driver version and add Sagi Grimberg as maintainer
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

- iser_hdr
- iser_data_buf
- iser_mem_reg
- iser_regd_buf
- iser_tx_desc
- iser_rx_desc
- iser_device
- iser_pi_context
- iser_conn
- ib_conn
- iser_comp
- iscsi_iser_task
- iser_global

While we're at it, change nit alignments in this file

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

Change logging: "iser:XXXX" to "iser: XXXX"
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Singal completion of every 32 scsi commands and suppress all the rest.
We don't do anything upon getting the completion so no need to "just
consume" it.  Cleanup of scsi command is done in cleanup_task callback.

Still keep dataout and control send completions as we may need to
cleanup there. This helps reducing the amount of interrupts/completions
in the IO path.
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Poll in batch of 16. Since we don't want it on the stack, keep under
iser completion context (iser_comp).
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Avoid post_send counting (atomic) in the IO path just to keep track of
how many completions we need to consume.  Use a beacon post to indicate
that all prior posts completed.
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 will solve a possible condition where we might miss TX completion
(flush error) during session teardown.  Since we are using a single
CQ, we don't need to actively drain the TX CQ, instead just wait for
flush_completion (when counters reach zero) and remove iser_poll_for_flush_errors().

This patch might introduce a minor performance regression on its own,
but the next patches will enhance performance using a single CQ for RX
and TX.
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Introduce iser_comp which centralizes all iser completion related
items and is referenced by iser_device and each ib_conn.
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

iscsi daemon is in user-space, thus we can't rely on it to be invoked
at connection teardown (if not running or does not receive CPU time).

This patch addresses the issue by re-structuring iSER connection
teardown logic and CM events handling.

The CM events will dictate the RDMA resources destruction (ib_conn)
and iser_conn is kept around as long as iscsi_conn is left around
allowing iscsi/iser callbacks to continue after RDMA transport was
destroyed.

This patch introduces a separation in logic when handling CM events:

- DISCONNECTED_HANDLER, ADDR_CHANGED
  This events indicate the start of teardown process.
  Actions:
  1. Terminate the connection: rdma_disconnect (send DREQ/DREP)
  2. Notify iSCSI of connection failure
  3. Change state to TERMINATING
  4. Poll for all flush errors to be consumed

- TIMEWAIT_EXIT, DEVICE_REMOVAL
  These events indicate the final stage of termination process and
  we can free RDMA related resources.
  Actions:
  1. Call disconnected handler (we are not guaranteed that DISCONNECTED
     event was invoked in the past)
  2. Cleanup RDMA related resources
  3. For DEVICE_REMOVAL return non-zero rc from cma_handler to
     implicitly destroy the cm_id (Can't rely on user-space, make sure
     we have forward progress)

We replace flush_completion (indicate all flushes were consumed) with
ib_completion (rdma resources were cleaned up).

The iser_conn_release_work will wait for teardown completions:

- conn_stop was completed (tasks were cleaned-up) - stop_completion
- RDMA resources were destroyed - ib_completion

And then will continue to free iser connection representation (iser_conn).
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NAriel Nahum <arieln@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>

Signed-off-by: NRoi Dayan <roid@mellanox.com>
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Structure that describes the RDMA relates connection objects.  Static
member of iser_conn.

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

Two reasons why we choose to do this:

1. No point today calling struct iser_conn by another name ib_conn
2. In the next patches we will restructure iser control plane representation
   - struct iser_conn: connection logical representation
   - struct ib_conn: connection RDMA layout representation

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

Instead of waiting for events and condition changes of the iser
connection state, we wait for explicit completion of connection
establishment and teardown.

Separate connection establishment wait object from the teardown object
to avoid a situation where racing connection establishment and
teardown may concurrently wakeup each other.

ep_poll will wait for up_completion invoked by
iser_connected_handler() and iser release worker will wait for
flush_completion before releasing the connection.

Bound the completion wait with a 30 seconds timeout for cases where
iscsid (the user space iscsi daemon) is too slow or gone.
Signed-off-by: NAriel Nahum <arieln@mellanox.com>
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

The iser connection state lookups and transitions are not fully protected.

Some transitions are protected with a spinlock, and in some cases the
state is accessed unprotected due to specific assumptions of the flow.

Introduce a new mutex to protect the connection state access. We use a
mutex since we need to also include a scheduling operations executed
under the state lock.

Each state transition/condition and its corresponding action will be
protected with the state mutex.

The rdma_cm events handler acquires the mutex when handling connection
events. Since iser connection state can transition to DOWN
concurrently during connection establishment, we bailout from
addr/route resolution events when the state is not PENDING.

This addresses a scenario where ep_poll retries expire during CMA
connection establishment. In this case ep_disconnect is invoked while
CMA events keep coming (address/route resolution, connected, etc...).
Signed-off-by: NAriel Nahum <arieln@mellanox.com>
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Replace struct sockaddr_in with struct sockaddr which supports both
IPv4 and IPv6, and print using the %pIS format directive.
Signed-off-by: NRoi Dayan <roid@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

iSER relies on refcounting to manage iser connections establishment
and teardown.

Following commit 39ff05db ("IB/iser: Enhance disconnection logic
for multi-pathing"), iser connection maintain 3 references:

 - iscsi_endpoint (at creation stage)
 - cma_id (at connection request stage)
 - iscsi_conn (at bind stage)

We can avoid taking explicit refcounts by correctly serializing iser
teardown flows (graceful and non-graceful).

Our approach is to trigger a scheduled work to handle ordered teardown
by gracefully waiting for 2 cleanup stages to complete:

 1. Cleanup of live pending tasks indicated by iscsi_conn_stop completion
 2. Flush errors processing

Each completed stage will notify a waiting worker thread when it is
done to allow teardwon continuation.

Since iSCSI connection establishment may trigger endpoint disconnect
without a successful endpoint connect, we rely on the iscsi <-> iser
binding (.conn_bind) to learn about the teardown policy we should take
wrt cleanup stages.

Since all cleanup worker threads are scheduled (release_wq) in
.ep_disconnect it is safe to assume that when module_exit is called,
all cleanup workers are already scheduled. Thus proper module unload
shall flush all scheduled works before allowing safe exit, to
guarantee no resources got left behind.
Signed-off-by: NAriel Nahum <arieln@mellanox.com>
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Reviewed-by: NRoi Dayan <roid@mellanox.com>
Reviewed-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Update Mellanox copyrights for 2014 on the iser initiator driver.
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

The iscsi stack has existing mechanisms to link back and forth between
the iscsi connection and the iscsi transport (e.g iser/tcp) connection.

This is done through a dd_data pointer field in struct iscsi_conn
which can be set to point to the transport connection, etc.

The iscsi_iser_conn structure was used to get this linking done in
another way, which is uneeded and adds extra complication to the iser
code, so we just remove it.
Signed-off-by: NAriel Nahum <arieln@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@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>

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>