The sysfs attribute /sys/class/fc_host/hostX/port_state was not set by
zfcp so far.

Now, the appropriate members of the fc_function_template struct are
set during its initialziation. The first is a boolean to show the port
state. The second is a function pointer to the function
zfcp_get_host_port_state, which reads the port state from our adapter
status bits and calls fc_host_port_state with the approriate port
state afterwards.
Signed-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>

Cleanup the messages used in the zfcp driver: Remove unnecessary debug
and trace message and convert the remaining messages to standard
kernel macros. Remove the zfcp message macros and while updating the
whole flie also update the copyright headers.
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

The latency information is provided on a SCSI device level (LUN)
which can be found at the following location

 /sys/class/scsi_device/<H:C:T:L>/device/cmd_latency
 /sys/class/scsi_device/<H:C:T:L>/device/read_latency
 /sys/class/scsi_device/<H:C:T:L>/device/write_latency

Each sysfs attribute provides the available data: min, max and sum for
fabric and channel latency and the number of requests processed.

An overrun of the variables is neither detected nor treated.  The file
has to be read twice to make a meaningful statement, because only the
differences of the values between the two reads can be used.  A reset
of the values can be achieved by writing to the attribute.
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 new FCP adapter statistics provide a variety of information about
the virtual adapter (subchannel). In order to collect this information
the zfcp driver is extended to query this information.

The information provided by the new FCP adapter statistics can be
fetched by reading from the following files in the sysfs filesystem

/sys/class/scsi_host/host<n>/seconds_active
/sys/class/scsi_host/host<n>/requests
/sys/class/scsi_host/host<n>/megabytes
/sys/class/scsi_host/host<n>/utilization

These are the statistics on a virtual adapter (subchannel) level.

The information provided is raw and not modified or interpreted by any
means.  No interpretation or modification of the values is done by the
zfcp driver.
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 testcase
# chchp -v 0 0.da && sleep 59 && chchp -v 1 0.da
results in this deadlock situation:

STACK TRACE FOR TASK: 0x7e9a2048 (zfcperp0.0.c613)
0 schedule+816 [0x356b3c]
1 schedule_timeout+172 [0x357340]
2 wait_for_common+192 [0x3565fc]
3 flush_cpu_workqueue+116 [0x52af0]
4 flush_workqueue+116 [0x533b8]
5 fc_remote_port_add+64 [0x1c83ec]
6 zfcp_erp_thread+4534 [0x26585a]
7 kernel_thread_starter+6 [0x195d2]

STACK TRACE FOR TASK: 0x7f8ec048 (fc_wq_0)
0 schedule+816 [0x356b3c]
1 zfcp_erp_wait+104 [0x264568]
2 zfcp_scsi_slave_destroy+64 [0x261b24]
3 __scsi_remove_device+154 [0x1c24ba]
4 scsi_remove_device+62 [0x1c2512]
5 __scsi_remove_target+198 [0x1c25ea]
6 __remove_child+58 [0x1c26d6]
7 device_for_each_child+66 [0x1ab566]
8 scsi_remove_target+98 [0x1c268a]
9 run_workqueue+200 [0x5272c]
10 worker_thread+146 [0x52882]
11 kthread+140 [0x58360]
12 kernel_thread_starter+6 [0x195d2]

Remove the zfcp_erp_wait call that is not required here to prevent the
deadlock situation.
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NMartin Peschke <mp3@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

drivers/s390/scsi/zfcp_aux.c: In function ‘zfcp_fsf_incoming_els_rscn’:
drivers/s390/scsi/zfcp_aux.c:1379: warning: cast from pointer to integer of
different size
drivers/s390/scsi/zfcp_aux.c: In function ‘zfcp_fsf_incoming_els_plogi’:
drivers/s390/scsi/zfcp_aux.c:1432: warning: cast from pointer to integer of
different size
drivers/s390/scsi/zfcp_aux.c: In function ‘zfcp_fsf_incoming_els_logo’:
drivers/s390/scsi/zfcp_aux.c:1457: warning: cast from pointer to integer of
different size
..

Just passing pointers rids us of these warnings and improves readability.
Signed-off-by: NMartin Peschke <mp3@de.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

This patch allows any recovery event to be traced back to an exact
cause, e.g. a particular request identified by an id (address).
Signed-off-by: NMartin Peschke <mp3@de.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

This patch writes a trace record which provides information about state
changes for adapters, ports and units, e.g. target failure, targets becoming
online, targets being temporarily blocked due to pending recovery, targets
which have been recovered successfully etc.
Signed-off-by: NMartin Peschke <mp3@de.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

[based on proposal from Mike Christie <michaelc@cs.wisc.edu>, this
patch adds some simplifications to the handler functions]

With the new target reset handler callback in the SCSI midlayer, the
device reset handler in zfcp can be split in two parts. Now, zfcp does
not have to track anymore whether the device supports LUN resets, so
remove this flag and let the SCSI midlayer decide what to do.

The device reset handler simply issues a LUN reset and the target
reset handler a target reset.
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

We need to hold the queue-lock when checking whether we still have a valid
unit/port handle for the FCP command, i.e whether we can issue this request for
this unit/port. If the error recovery is about to close this unit/port, then it
competes for the queue-lock. If the close request issued by the error recovery
wins, then it is guaranteed that this unit/port has been blocked for other
requests.
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NMartin Peschke <mp3@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

When adding an invalid LUN, there is a deadlock between the add
via scsi_scan_target and the slave_destroy handler: The handler
waits for the scan to complete, but for an invalid unit,
scsi_scan_target directly calls the slave_destroy handler.

Fix the deadlock by removing the wait in the slave_destroy
handler, it was not necessary anyway.
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

The callback function used by zfcp always returns success,
which is an indication for the SCSI midlayer to stop error
handling. Remove the bus_reset callback, since the same
function will be called via the host_reset callback.
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Cleanup the whitepace from the entire zfcp driver to prevent
to have those changes in future feature or function patches.
Signed-off-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

cleanup, using ERP request mempool for all ERP versions of
the exchange functions (exchange_config (ECD), exchange_port (EPD) )
providing individual versions of the ECD, EPD functions for ERP
and other purposes (_sync).
Signed-off-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Remove braces for only one statement
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

fix memory leak.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

IO stall after deleting and path checker changes after reenabling zfcp device

Setting one zfcp device offline using chccwdev in a multipath
environment and waiting will lead to IO stall on all paths.
After setting the zfcp device back online using chccwdev,
the devices with io stall will have a different path checker.
Devices corresponding to the deleted units are never freed.
This has the effect that 'slave_destroy' is never called and zfcp
still thinks that this unit is registered
(ZFCP_STATUS_UNIT_REGISTERED is still set). Hence the erp
routine is not called correctly and the unit is not enabled properly.

Do not delete rport and the sdev. Just set the host to block on
'offline'. Setting host online again will then remove the blocked status
and everything is fine again.
Signed-off-by: NMichael Loehr <mloehr2@linux.vnet.ibm.com>
Signed-off-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Simplify request ID management and make sure that frequently used
functions are inlined. Also fix a memory leak in zfcp_adapter_enqueue()
which only gets hit in error handling.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

The SCSI stack requires low level drivers to register and
unregister devices. For zfcp this leads to the situation where
zfcp calls the SCSI stack, the SCSI tries to scan the new device
and the scan SCSI command fails. This would require the zfcp erp,
but the erp thread is already blocked in the register call.

The fix is to make sure that the calls from the ERP thread to
the SCSI stack do not block the ERP thread. In detail:
1) Use a workqueue to avoid blocking of the scsi_scan_target calls.
2) When removing a unit make sure that no scsi_scan_target call is
   pending.
3) Replace scsi_flush_work with scsi_target_unblock. This avoids
   blocking and has the same result.
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Define ZFCP_MAX_SECTORS and initialize scsi_host_template.max_sectors
with appropriate value.
Signed-off-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

All on stack DECLARE_COMPLETIONs should be replaced by:
DECLARE_COMPLETION_ONSTACK
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: NIngo Molnar <mingo@elte.hu>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix the fix ... One of my previous fixes introduced removal of all fsf
requests in zfcp's eh_host_reset_handler. But this must not happen
before qdio queues are shut down. So, I revert the changes of
zfcp_scsi_eh_host_reset_handler.
Signed-off-by: NAndreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

This instance will be used whenever a timer is needed for
a request by zfcp.
Signed-off-by: NAndreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

zfcp's eh_abort_handler used the wrong request ID to
identify the request to be aborted. The bug was introduced
with commit fea9d6c7
for improved management of request IDs. The bug is
fixed with this patch.
Signed-off-by: NAndreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Create private slab caches in order to guarantee proper alignment of
data structures that get passed to hardware.

Sidenote: with this patch slab cache debugging will finally work on s390
(at least no known problems left).

Furthermore this patch does some minor cleanups:
- store ptr for transport template in struct zfcp_data
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NAndreas Herrmann <aherrman@de.ibm.com>
Compile fix ups and
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Bug fixes for zfcp's erp:
- trigger adapter reopen if do_QDIO fails
- avoid erp deadlock if registration of scsi target or remote port hang
- do not treat as error if exchange port data fails
- decrease timeout for target reset and aborts
- mark unit failed if slave_destroy is called

Additionally some code cleanup was done:
- made some functions void when retval is not of interest
- shortened initialization of zfcp's host_template
- corrected some comments
Signed-off-by: NAndreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

If zfcp's port erp fails we now call fc_remote_port_delete. This helps
to avoid offlined scsi devices if scsi commands time out due to path
failures. When an adapter erp fails we call fc_remote_port_delete for
all ports on that adapter.
Signed-off-by: NAndreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Signed-off-by: NRalph Wuerthner <rwuerthn@de.ibm.com>
Signed-off-by: NAndreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Removed some macros, struct members and typedefs which were
unused or not necessary.
Signed-off-by: NAndreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Replace kmalloc/memset by kzalloc or kcalloc.
Signed-off-by: NAndreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Removed some useless comments.
Signed-off-by: NAndreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Copyright update, shortened file headers, shortened author information.
Signed-off-by: NAndreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

The patch fixes following issues:

(1) Replace scsi_add_device with scsi_scan_target.
(Thus the rport instead of the scsi_host becomes parent of a
scsi_target again.)

(2) Avoid scsi_device allocation during registration of an remote port.
(Would be done during fc_scsi_scan_rport.)

(3) Fix queuecommand behaviour when an zfcp unit is blocked.
(Call scsi_done with DID_NO_CONNECT instead of returning
SCSI_MLQUEUE_DEVICE_BUSY otherwise we might end up waiting
for completion in blk_execute_rq for ever.)
Signed-off-by: NAndreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

It fixes a bug in zfcp which provokes a race
in scsi_scan.c. Finally this can lead to an Oops like:

kernel BUG at fs/sysfs/symlink.c:87!

Correctly set this_id for the host. Otherwise we provoke
a race between scsi_target_reap_work and concurrent
scsi_add_device.
Signed-off-by: NAndreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Avoid access to old fsf_requests if device reset is logged.
Signed-off-by: NMaxim Shchetynin <maxim@de.ibm.com>
Signed-off-by: NAndreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

- Remove all CVS generated information like e.g. revision IDs from
  drivers/s390 and include/asm-s390 (none present in arch/s390).

- Add newline at end of arch/s390/lib/Makefile to avoid diff message.
Acked-by: NAndreas Herrmann <aherrman@de.ibm.com>
Acked-by: NFrank Pavlic <pavlic@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Replaced zfcp adapter attributes with fc_host attributes:
fc_topology by port_type, physical_wwpn by permanent_port_name.
Make use of fc_host attribute supported_speeds.
Removed zfcp adapter attribute physical_s_id.
Signed-off-by: NAndreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>