linux/drivers/infiniband
Sagi Grimberg c47a3c9ed5 IB/iser: Fix DEVICE REMOVAL handling in the absence of iscsi daemon
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: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Ariel Nahum <arieln@mellanox.com>
Signed-off-by: Roi Dayan <roid@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-10-09 00:06:06 -07:00
..
core Merge branches 'core', 'ipoib', 'iser', 'mlx4', 'ocrdma' and 'qib' into for-next 2014-09-22 10:05:40 -07:00
hw Last late set of InfiniBand/RDMA fixes for 3.17: 2014-09-23 16:47:34 -07:00
ulp IB/iser: Fix DEVICE REMOVAL handling in the absence of iscsi daemon 2014-10-09 00:06:06 -07:00
Kconfig Merge branch 'ip-roce' into for-next 2014-01-22 23:24:21 -08:00
Makefile IB: Allow build of hw/ and ulp/ subdirectories independently 2014-06-02 14:51:12 -07:00