Keep the information about the device and model id in zfcp_ccw. This
requires an additional helper function to check for the privileged
cfdc subchannel, but it allows the removal of the redundant defines
from the zfcp_def header file.
Reviewed-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

If the destination ID (D_ID) of a remote storage port changed, e.g.
re-plugged cable on the switch in a different switch port, the port
was never (re-)attached within Linux. This patch fixes the broken
mapping between the WWPN and the D_ID.
Signed-off-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

In rare cases, open port request might timeout, erp calls
zfcp_port_put, port gets dequeued. Now, the late returning (or
dismissed) fsf-port-open calls the fsf_port_open_handler that tries to
reference the port data structure leading to a kernel oops.
Signed-off-by: NMartin Petermann <martin.petermann@de.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Add comments where there is a deliberate fall through in switch/case
statements. This makes some code checkers happy and makes it clear
that there is no missing break statement.
Reviewed-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

enum dma_data_direction only has the 4 values DMA_BIDIRECTIONAL,
DMA_TO_DEVICE, DMA_FROM_DEVICE and DMA_NONE. No need to have the
default case. While changing this, setup sbtype in one place to make
sparse happy.

The default value of retval is already -EIO, so remove the
additional assignment for these two cases.
Reviewed-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

zfcp did always set the queue_depth for SCSI devices to 32, not
allowing to change this. Introduce a kernel parameter zfcp.queue_depth
and the change_queue_depth callback to allow changing the queue_depth
when it is required.
Reviewed-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Update the newly introduced message for the boxed status to conform to
match the style of s390 and zfcp messages.
Reviewed-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

The zfcp traces used the fsf_req address in place of the req_id.
Change this to save the correct req_id.
Reviewed-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

The zfcp_port might have been removed, while the FC fast_io_fail timer
is still running and could trigger the terminate_rport_io callback.
Set the pointer to the zfcp_port to NULL and check accordingly
before using it.
Reviewed-by: NMartin Petermann <martin@linux.vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Before dropping the reference count with zfcp_adapter_put, increase it
with zfcp_adapter_get when issuing cfdc requests.
Reviewed-by: NMartin Petermann <martin@linux.vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

If this problem appears zfcp ports cannot be de-queued since it is
checked for a zero refcount. The port reference counting is wrong for
existing zfcp ports when e.g. an adapter gets on-line again. During
port scanning the reference counting for existing ports should not be
changed.
Signed-off-by: NMartin Petermann <martin.petermann@de.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

The current sbal counting can be wrong if a fsf request is
waiting for free sbals and at the same time qdio request queue
is shutdown and re-opened. Revering a previous patch fixes this
issue.
Signed-off-by: NMartin Petermann <martin.petermann@de.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

When the abort handler cannot find a pending FSF request, the request
completion could just be running. This means we cannot return SUCCESS,
since this would lead to call to scsi_done after exiting the SCSI
error handler which is not allowed.
Reviewed-by: NMartin Petermann <martin@linux.vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

A remote port remains in error state even if we receive a RSCN
stating that the connection is re-established. The port recovery
is not started due to a flag which is not reset.
The solution is to clear the flag in question before we trigger a ERP.
Signed-off-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Error codes specific to the control file requests are evaluated by the
actcli tool, so don't report -ENXIO for those. Generic problems are
still checked for outside the command specific handler.
Reviewed-by: NMartin Petermann <martin@linux.vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

On some hardware it can take some time to add a unit. If
some remove this unit during this process the remove will
fail.
Signed-off-by: NMartin Petermann <martin@linux.vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

The remote port remains in error state even if the connection
is re-established. A wrong precondition check was performed on
the port status leading to a cancellation of the port reopen.
Remove the pre-req check because it's not required and better
handled within the ERP.
Signed-off-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

The ERP thread is performing a task before it is executing the
corresponding down on the semaphore. The response handler of the
just started exchange config should wait for the completion by
performing a down on this semaphore. Since this semaphore is still
positive from the ERP enqueue the handler won't wait and therefore
the exchange config will always fail leaving the adapter in error.
The problem can be solved by performing the down on the semaphore
before starting an ERP task. This is the logically correct order.
Only walk the ERP loop if there is a task to perform.
Signed-off-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

The nameserver port might be in state online when the adapter is
offlined. On adapter reactivation the nameserver port is not
re-opened due to the PORT_ONLINE status. This results in an
unsuccessful recovery. In forcing the nameserver port status
to offline on all adapter offline events this issue is prevented.

Waiting for the reference count to drop to zero in
zfcp_wka_port_offline is not required, so remove it.
Signed-off-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

When running the scsi_scan from the zfcp workqueue and the target
device does not respond, the zfcp workqueue can block until the
scsi_scan hits a timeout. Move the work to the scsi host workqueue,
since this one is also used for the scan from the SCSI midlayer.
Signed-off-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Fix problem that zfcp_fsf_exchange_config_data_sync and
zfcp_fsf_exchange_config_data_sync could try to call zfcp_fsf_req_free
with a NULL pointer.
Reviewed-by: NMartin Petermann <martin@linux.vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Since we're setting the host port type now to FC_PORTTYPE_NPIV
for adapters running in NPIV mode we should allow this port type
for auto-port scanning as well.
Signed-off-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Avoid referencing a fsf request after sending it in fcp_fsf_req_send,
it might have already completed and deallocated.
Signed-off-by: NMartin Petermann <martin@linux.vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

It is a fairly common operation to have a pointer to a work and to need a
pointer to the delayed work it is contained in.  In particular, all
delayed works which want to rearm themselves will have to do that.  So it
would seem fair to offer a helper function for this operation.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Acked-by: NIngo Molnar <mingo@elte.hu>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Greg KH <greg@kroah.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If a ccw device did not respond in time during internal io, we set it
into boxed state. With this patch we have the following behaviour:
 * the ccw driver will get a notification if the device was online and
   goes into the boxed state
 * if the device was disconnected and got boxed nothing special is to be
   done (it will be handled in reprobing later)
 * if the device got boxed while initial sensing it will be unregistered
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Report the fc_host_port_type as FC_PORTTYPE_NPIV when the subchannel
is running in NPIV mode. This allows to see the correct type with
lsscsi -H -t --list
Acked-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

A scheduled work might still be pending, running while the adapter is
in progress to get dequeued from the system. This can lead to an
invalid pointer dereference (Oops).  Once the adpater is set online
again, ensure the nameserver environment is initialized to the
appropriate values again.
Signed-off-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Ensure the refcounting is correct even if we were not able to
schedule a work. In addition we have to make sure no scheduled
work is pending while we're dequeing the adapter from the
systems environment.
Signed-off-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

It will not be necessary to set the erp failed status bit
in case a SCSI device is removed by the SCSI mid layer.
In the case a SCSI device is unavailable for a short time
(15 to 20 seconds) a FCP unit will not get on-line again.
Signed-off-by: NMartin Petermann <martin@linux.vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Use the I/O blocking mechanism in the FC transport class to allow
faster failovers for multipathing:
- Call fc_remote_port_delete early to set the rport to BLOCKED.
- Check the rport status in queuecommand with fc_remote_portchkready
  to no longer accept new I/O for this port and fail the I/O with the
  appropriate scsi_cmnd result.
- Implement the terminate_rport_io handler to abort all pending I/O
  requests
- Return SCSI commands with DID_TRANSPORT_DISRUPTED while erp is
  running.
- When updating the remote port status, check for late changes and
  update the remote ports status accordingly.
Acked-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

After an error condition resolved a remote storage port was never
re-opened. The incoming RSCN was not processed accordingly due
to a misinterpreted status flag / return value combination.
Signed-off-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

The usage of the PCI flag to trigger interrupts is optional. Even
without setting the flag, qdio still receives interrupts to continue
working on the queue.  Remove the PCI flag from zfcp, it is not
necessary.
Acked-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

The current number based id ERP logging is replaced by a string
based tag version. The benefit is an easier location of the code in
question and the removal of the lengthy array referencing the
individual messages.
The string (7 bytes) based version does not use more space since those
bytes were "used" anyway due to the alignment of the structure.
The encoding of the 7 byte string is as follows
        [0-1] = filename
        [2-5] = task/function
        [6]   = section
Due to the character of this string (fixed length) a string
termination is not required here.
Signed-off-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

An adapter close was always performed whether it was required,
(e.g. in an error scenario) or not (e.g. initial open).
This patch is changing the process in only doing an
adapter close when it is required.
Signed-off-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

The status read response FSF_STATUS_READ_SUB_ERROR_PORT is not
defined in the specs and therefore not valid.
All occurrences are removed from the code.
Signed-off-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Issue ELS ADISC requests from workqueue. This allows the link test
request to be sent when the request queue is full due to I/O load for
other remote ports. It also simplifies request queue locking,
zfcp_fsf_send_fcp_command_task is now the only function that has
interrupts disabled from the caller. This is also a prereq for the FC
passthrough support that issues ELS requests from userspace.
Acked-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

When the SCSI midlayer is running error recovery, the low-level error
recovery in zfcp could be running and preventing the SCSI midlayer to
issue error recovery requests. To avoid unnecessary error recovery
escalation, wait for the zfcp erp to finish and retry if necessary.

While reworking the SCSI eh handlers, alsa cleanup the code and
simplify the interface from zfcp_scsi to the fsf layer.
Acked-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

For calls from zfcp erp, scsi_eh and sysfs switch the calls issuing
FSF requests to zfcp_fsf_req_sbal_get to wait for free SBALs.
Acked-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Only increment the req_id for successfully issued requests. This
avoids some confusion when debugging issued fsf requests.
Acked-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

The lock only needs to protect the softirq context called from qdio
against the userspace context called from sysfs. spin_lock and
spin_lock_bh is enough.
Acked-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>