This module parameter forces memory registration even for
a continuous memory region. It is true by default as sending
an all-physical rkey with remote permissions might be insecure.
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Chaning of send work requests benefits performance by
reducing the send queue lock contention (acquired in
ib_post_send) and saves us HW doorbells which is posted
only once.

Currently, in normal IO flows iser does not chain the CDB send
work request with the registration work request. Also in PI
flows, signature work requests are not chained as well.

Lets chain those and post only once.
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

iser support up to 512KB data transfer in a single scsi command.
This means that larger IOs will split to different request. While
iser can easily saturate FDR/EDR wires, some arrays are fine tuned
for 1MB (or larger) IO sizes, hence add an option to support larger
transfers (up to 8MB) if the device allows it.

Given that a few target implementations don't support data transfers
of more than 512KB by default and the fact that larger IO sizes require
more resources, we introduce a module parameter to determine the
maximum number of 512B sectors in a single scsi command.
Users that are interested in larger transfers can change this value given
that the target supports larger transfers.

At the moment, iser works in 4K pages granularity, In a later stage
we will get it to work with system page size instead.

IO operations that consists of N pages will need a page vector
of size N+1 in case the first SG element contains an offset. Given
that some devices allocates memory regions in powers of 2, this
means that allocating a region with N+1 pages, will result in
region resources allocation of the next power of 2. Since we don't
want that to happen, in case we are in the limit of IO size supported
and the first SG element has an offset, we align the SG list using a
bounce buffer (which is OK given that this is not likely to happen a lot).
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Hard coded for now. This will allow to allocate different
sized MRs depending on the IO size needed (and device
capabilities).

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

iser_reg_rdma_mem_[fastreg|fmr] share a lot of code, and
logically do the same thing other than the buffer registration
method itself (iser_fast_reg_mr vs. iser_fast_reg_fmr).
The DIF logic is not implemented in the FMR flow as there is no
existing device that supports FMRs and Signature feature.

This patch unifies the flow in a single routine iser_reg_rdma_mem
and just split to fmr/frwr for the buffer registration itself.

Also, for symmetry reasons, unify iser_unreg_rdma_mem (which will
call the relevant device specific unreg routine).
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 for fmrs we will hold a single registration descriptor
as no need for multiple like in the frwr mode (descriptor
for each task). This change helps unifying the duplicate
registration code paths.
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 will allow us to unify the memory registration code path between
the various methods which vary by the device capabilities. This change
will make it easier and less intrusive to remove fmr_pools from the
code when we'd want to.

The reason we use a single descriptor is to avoid taking a
redundant spinlock when working with FMRs.

We also change the signature of iser_reg_page_vec to make it match
iser_fast_reg_mr (and the future indirect registration method).
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 having it a part of the connection structure,
have it be under a dedicated (embedded) structure in the
connection. A logical separation of the registration pool
and the connection structure.
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NAdir Lev <adirl@mellanox.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Move all the per-device function pointers to an easy
extensible iser_reg_ops structure that contains all
the iser registration operations.
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Avoid struct names without iser_ prefix.

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

Have fast_reg_descriptor hold struct iser_reg_resources
(mr, frpl, valid flag). This will be useful when the
actual buffer registration routines will be passed with
the needed registration resources (i.e. iser_reg_resources)
without being aware of their nature (i.e. data or protection).

In order to achieve this, we remove reg_indicators flags container
and place specific flags (mr_valid) within iser_reg_resources struct.
We also place the sig_mr_valid and sig_protcted flags in iser_pi_context.

This patch also modifies iser_fast_reg_mr to receive the
reg_resources instead of the fast_reg_descriptor and a data/protection
indicator.
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NAdir Lev <adirl@mellanox.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

If iser_initialize_task_headers() routine failed before
dma mapping, we should not attempt to unmap in cleanup_task().

Fixes: 7414dde0 (IB/iser: Fix race between iser connection ...)
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

In some rare cases, IO operations may be not aligned to page
boundaries. This prevents iser from performing fast memory
registration. In order to overcome that iser uses a bounce
buffer to carry the transaction. We basically allocate a buffer
in the size of the transaction and perform a copy.

The buffer allocation using kmalloc is too restrictive since it
requires higher order (atomic) allocations for large transactions
(which may result in memory exhaustion fairly fast for some workloads).
We rewrite the bounce buffer code path to allocate scattered pages
and perform a copy between the transaction sg and the bounce sg.
Reported-by: NAlex Lyakas <alex@zadarastorage.com>
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

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>