The trace record for SCSI abort requests has a field for the request
id of the request to be aborted. Put the real request id instead of
zero.
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>

Under certain conditions it is possible that a WKA port ist not opened
within the expected timeframe of half a second. In this situation
the WKA port remains in the state OPENING preventing any succeding
request to open the port. This led to unrecoverable remote ports.
Fixing this by always setting an appropriate WKA port status before
leaving the function and removing the timeout value here since it's
not needed here because the general timeout processing would deal
with it if 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>

In a LOWMEM condition an ERP notification would have been sent twice
causing an unpredictable behaviour of 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>

When calling fc_remote_port_add make sure to not call it again before
fc_remote_port_delete has been called. In other words, ensure to
create a new fc_rport, then delete it, then create a new one again.
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>

Depending on interruptions on some storage systems, the complete
channel can stall which looks like an outbound queue stall to Linux.
When trying to acquire a free SBAL for a non-SCSI command, zfcp waits
for 5 seconds for a free slot to appear. This is the right place to
detect a queue stall: If the wait times out, we assume a stalled queue
and try to recover this.

The overall strategy should be to trigger the erp from specific
events, and not try an overall escalation from one failed port to a
full-blown queue recovery. If we manage to send a command, the status
codes for this command or a timeout will trigger the right follow-on
actions.
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 an action fails, retry it until the erp count exceeds the
threshold. If there is something fundamentally wrong, the FSF layer
will trigger a more appropriate action depending on the FSF status
codes.

The followup for successful actions is a different followup than
retrying failed actions, so split the code two functions to make this
clear.
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>

After closing the port, we want it to be "not open" to consider the
action to be successful.
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>

-ENOMEM is for memory allocation problems, -EIO for queue/SBAL
allocation problems.
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 ELS ADISC and the GID_PN requests sent from zfcp fit into
unchained FSF requests. Change the FSF allocation logic to use
unchained requests whenever possible where everything fits in one
SBAL. This avoids acquiring more SBALs than necessary, especially
during zfcp recovery when things might be stalled.
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_erp_notify uses the ZFCP_ERP_STATUS_* flags, so it is
ZFCP_STATUS_ERP_LOWMEM instead of ZFCP_ERP_NOMEM. Signalling
ZFCP_ERP_FAILED is not necessary, the missing d_id will show that the
nameserver did not return the d_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>

When a fsf_req or a qtcb cannot be allocated return -ENOMEM instead of
-EIO.
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>

req_q_util is not atomic, so the qdio_stat_lock must be held when
reading this variable.
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>

We should not modify the port status after triggering an ERP action
for the port. It is not guaranteed which status is finally active
when the ERP action is performed. This can lead to situations which
are unwanted and hard to debug in case of a failure.
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>

Signed-off-by: NMartin Petermann <martin.petermann@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Don't access the block layer request, get the payload length instead
from the FC job. Simplify access to the zfcp_port, only the d_id is
required, if the port is no longer accessed later. This is possible
when the els_handler does not access the port pointer from the ELS
request.
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>

Provide the ability to do fibre channel requests from the userspace to
our zfcp driver.  Patch builds upon extension to the fibre channel
tranport class by James Smart and Seokmann Ju.  See here
http://marc.info/?l=linux-scsi&m=123808882309133&w=2Signed-off-by: NSven Schuetz <sven@linux.vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Signed-off-by: NMartin Olsson <martin@minimum.se>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

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>