scsi: zfcp: Declare SCSI host template const

Make it explicit that the SCSI host template is not modified.

Acked-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230322195515.1267197-9-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: zfcp: Change the type of all fsf request id fields and variables to u64

We use different integer types throughout zfcp to store the FSF request ID
and related values; some places use 'unsigned long' and others 'u64'. On
s390x these are effectively the same type, but this might cause confusions
and is generally inconsistent.

The specification for the used hardware specifies this value as a 64-bit
number, and ultimately we use this value to communicate with the hardware,
so it makes sense to change the type of all these variables to 'u64' where
we can. The only exception being when we store it in the 'host_scribble'
field of a 'struct scsi_cmnd'; for this case we add a build time check to
make sure they are compatible.

Link: https://lore.kernel.org/r/9c9cbe5acc2b419a22dce2fed847e3db91b60201.1677000450.git.bblock@linux.ibm.com
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: zfcp: Switch to attribute groups

struct device supports attribute groups directly but does not support
struct device_attribute directly. Hence switch to attribute groups.

Link: https://lore.kernel.org/r/20211012233558.4066756-7-bvanassche@acm.org
Acked-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: zfcp_scsi: Call scsi_done() directly

Conditional statements are faster than indirect calls. Hence call
scsi_done() directly.

Link: https://lore.kernel.org/r/20211007202923.2174984-8-bvanassche@acm.org
Acked-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Introduce scsi_build_sense()

Introduce scsi_build_sense() as a wrapper around scsi_build_sense_buffer()
to format the buffer and set the correct SCSI status.

Link: https://lore.kernel.org/r/20210427083046.31620-8-hare@suse.de
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: zfcp: Move allocation of the shost object to after xconf- and xport-data

At the moment we allocate and register the Scsi_Host object corresponding
to a zfcp adapter (FCP device) very early in the life cycle of the adapter
- even before we fully discover and initialize the underlying
firmware/hardware. This had the advantage that we could already use the
Scsi_Host object, and fill in all its information during said discover and
initialize.

Due to commit 737eb78e82d5 ("block: Delay default elevator initialization")
(first released in v5.4), we noticed a regression that would prevent us
from using any storage volume if zfcp is configured with support for DIF or
DIX (zfcp.dif=1 || zfcp.dix=1). Doing so would result in an illegal memory
access as soon as the first request is sent with such an configuration. As
example for a crash resulting from this:

scsi host0: scsi_eh_0: sleeping
scsi host0: zfcp
qdio: 0.0.1900 ZFCP on SC 4bd using AI:1 QEBSM:0 PRI:1 TDD:1 SIGA: W AP
scsi 0:0:0:0: scsi scan: INQUIRY pass 1 length 36
Unable to handle kernel pointer dereference in virtual kernel address space
Failing address: 0000000000000000 TEID: 0000000000000483
Fault in home space mode while using kernel ASCE.
AS:0000000035c7c007 R3:00000001effcc007 S:00000001effd1000 P:000000000000003d
Oops: 0004 ilc:3 [#1] PREEMPT SMP DEBUG_PAGEALLOC
Modules linked in: ...
CPU: 1 PID: 783 Comm: kworker/u760:5 Kdump: loaded Not tainted 5.6.0-rc2-bb-next+ #1
Hardware name: ...
Workqueue: scsi_wq_0 fc_scsi_scan_rport [scsi_transport_fc]
Krnl PSW : 0704e00180000000 000003ff801fcdae (scsi_queue_rq+0x436/0x740 [scsi_mod])
R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 RI:0 EA:3
Krnl GPRS: 0fffffffffffffff 0000000000000000 0000000187150120 0000000000000000
000003ff80223d20 000000000000018e 000000018adc6400 0000000187711000
000003e0062337e8 00000001ae719000 0000000187711000 0000000187150000
00000001ab808100 0000000187150120 000003ff801fcd74 000003e0062336a0
Krnl Code: 000003ff801fcd9e: e310a35c0012 lt %r1,860(%r10)
000003ff801fcda4: a7840010 brc 8,000003ff801fcdc4
#000003ff801fcda8: e310b2900004 lg %r1,656(%r11)
>000003ff801fcdae: d71710001000 xc 0(24,%r1),0(%r1)
000003ff801fcdb4: e310b2900004 lg %r1,656(%r11)
000003ff801fcdba: 41201018 la %r2,24(%r1)
000003ff801fcdbe: e32010000024 stg %r2,0(%r1)
000003ff801fcdc4: b904002b lgr %r2,%r11
Call Trace:
[<000003ff801fcdae>] scsi_queue_rq+0x436/0x740 [scsi_mod]
([<000003ff801fcd74>] scsi_queue_rq+0x3fc/0x740 [scsi_mod])
[<00000000349c9970>] blk_mq_dispatch_rq_list+0x390/0x680
[<00000000349d1596>] blk_mq_sched_dispatch_requests+0x196/0x1a8
[<00000000349c7a04>] __blk_mq_run_hw_queue+0x144/0x160
[<00000000349c7ab6>] __blk_mq_delay_run_hw_queue+0x96/0x228
[<00000000349c7d5a>] blk_mq_run_hw_queue+0xd2/0xe0
[<00000000349d194a>] blk_mq_sched_insert_request+0x192/0x1d8
[<00000000349c17b8>] blk_execute_rq_nowait+0x80/0x90
[<00000000349c1856>] blk_execute_rq+0x6e/0xb0
[<000003ff801f8ac2>] __scsi_execute+0xe2/0x1f0 [scsi_mod]
[<000003ff801fef98>] scsi_probe_and_add_lun+0x358/0x840 [scsi_mod]
[<000003ff8020001c>] __scsi_scan_target+0xc4/0x228 [scsi_mod]
[<000003ff80200254>] scsi_scan_target+0xd4/0x100 [scsi_mod]
[<000003ff802d8b96>] fc_scsi_scan_rport+0x96/0xc0 [scsi_transport_fc]
[<0000000034245ce8>] process_one_work+0x458/0x7d0
[<00000000342462a2>] worker_thread+0x242/0x448
[<0000000034250994>] kthread+0x15c/0x170
[<0000000034e1979c>] ret_from_fork+0x30/0x38
INFO: lockdep is turned off.
Last Breaking-Event-Address:
[<000003ff801fbc36>] scsi_add_cmd_to_list+0x9e/0xa8 [scsi_mod]
Kernel panic - not syncing: Fatal exception: panic_on_oops

While this issue is exposed by the commit named above, this is only by
accident. The real issue exists for longer already - basically since it's
possible to use blk-mq via scsi-mq, and blk-mq pre-allocates all requests
for a tag-set during initialization of the same. For a given Scsi_Host
object this is done when adding the object to the midlayer
(`scsi_add_host()` and such). In `scsi_mq_setup_tags()` the midlayer
calculates how much memory is required for a single scsi_cmnd, and its
additional data, which also might include space for additional protection
data - depending on whether the Scsi_Host has any form of protection
capabilities (`scsi_host_get_prot()`).

The problem is now thus, because zfcp does this step before we actually
know whether the firmware/hardware has these capabilities, we don't set any
protection capabilities in the Scsi_Host object. And so, no space is
allocated for additional protection data for requests in the Scsi_Host
tag-set.

Once we go through discover and initialize the FCP device firmware/hardware
fully (this is done via the firmware commands "Exchange Config Data" and
"Exchange Port Data") we find out whether it actually supports DIF and DIX,
and we set the corresponding capabilities in the Scsi_Host object (in
`zfcp_scsi_set_prot()`). Now the Scsi_Host potentially has protection
capabilities, but the already allocated requests in the tag-set don't have
any space allocated for that.

When we then trigger target scanning or add scsi_devices manually, the
midlayer will use requests from that tag-set, and before sending most
requests, it will also call `scsi_mq_prep_fn()`. To prepare the scsi_cmnd
this function will check again whether the used Scsi_Host has any
protection capabilities - and now it potentially has - and if so, it will
try to initialize the assumed to be preallocated structures and thus it
causes the crash, like shown above.

Before delaying the default elevator initialization with the commit named
above, we always would also allocate an elevator for any scsi_device before
ever sending any requests - in contrast to now, where we do it after
device-probing. That elevator in turn would have its own tag-set, and that
is initialized after we went through discovery and initialization of the
underlying firmware/hardware. So requests from that tag-set can be
allocated properly, and if used - unless the user changes/disabled the
default elevator - this would hide the underlying issue.

To fix this for any configuration - with or without an elevator - we move
the allocation and registration of the Scsi_Host object for a given FCP
device to after the first complete discovery and initialization of the
underlying firmware/hardware. By doing that we can make all basic
properties of the Scsi_Host known to the midlayer by the time we call
`scsi_add_host()`, including whether we have any protection capabilities.

To do that we have to delay all the accesses that we would have done in the
past during discovery and initialization, and do them instead once we are
finished with it. The previous patches ramp up to this by fencing and
factoring out all these accesses, and make it possible to re-do them later
on. In addition we make also use of the diagnostic buffers we recently
added with

commit 92953c6e0aa7 ("scsi: zfcp: signal incomplete or error for sync exchange config/port data")
commit 7e418833e689 ("scsi: zfcp: diagnostics buffer caching and use for exchange port data")
commit 088210233e6f ("scsi: zfcp: add diagnostics buffer for exchange config data")

(first released in v5.5), because these already cache all the information
we need for that "re-do operation" - the information cached are always
updated during xconf or xport data, so it won't be stale.

In addition to the move and re-do, this patch also updates the
function-documentation of `zfcp_scsi_adapter_register()` and changes how it
reports if a Scsi_Host object already exists. In that case future
recovery-operations can skip this step completely and behave much like they
would do in the past - zfcp does not release a once allocated Scsi_Host
object unless the corresponding FCP device is deconstructed completely.

Link: https://lore.kernel.org/r/030dd6da318bbb529f0b5268ec65cebcd20fc0a3.1588956679.git.bblock@linux.ibm.com
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: zfcp: Move fc_host updates during xport data handling into fenced function

When executing exchange port data for a FCP device for the first time, or
after an adapter recovery, we update several properties of the fibre
channel host object which represents that FCP device.

When moving the scsi host object allocation and registration - and thus
also the fibre channel host object allocation - to after the first exchange
config and exchange port data, this is not possible for the former case.

Move all these update into separate, and fenced function that first checks
whether the scsi host object already exists or not, before making the
updates.

During the first ever exchange port data in the adapter life cycle this
will make the exchange port data handler skip over this update step, but we
can repeat it later, after we allocated the scsi host object.

For any further recovery of that adapter the work flow is only changed
slightly because then the scsi host object already exists and we don't free
it until we release the adapter completely at the end of its life cycle.

Link: https://lore.kernel.org/r/ae454c2dc6da0b02907c489af91d0b211d331825.1588956679.git.bblock@linux.ibm.com
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: zfcp: Move shost updates during xconfig data handling into fenced function

When executing exchange config data for a FCP device for the first time, or
after an adapter recovery, we update several properties of the scsi host or
fibre channel host object that represent that FCP device.

When moving the scsi host object allocation and registration - and thus
also the fibre channel host object allocation - to after the first exchange
config and exchange port data, this is not possible for the former case.

Move all these update into separate, and fenced function that first checks
whether the scsi host object already exists or not, before making the
updates.

During the first ever exchange config data in the adapter life cycle this
will make the exchange config data handler skip over this update step, but
we can repeat it later, after we allocated the scsi host object.

For any further recovery of that adapter the work flow is only changed
slightly because then the scsi host object already exists and we don't free
it until we release the adapter completely at the end of its life cycle.

Link: https://lore.kernel.org/r/5fc3f4d38d4334f7aa595497c6f7865fb1102e0f.1588956679.git.bblock@linux.ibm.com
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: zfcp: wire previously driver-specific sysfs attributes also to fc_host

Manufacturer, HBA model, firmware version, and hardware version. Use the
same value format as for the driver-specific attributes. Keep the
driver-specific attributes for stable user space sysfs API.

Link: https://lore.kernel.org/r/20200312174505.51294-4-maier@linux.ibm.com
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: zfcp: expose fabric name as common fc_host sysfs attribute

FICON Express8S or older, as well as card features newer than FICON
Express16S+ have no certain firmware level requirement.

FICON Express16S or FICON Express16S+ have the following
minimum firmware level requirements to show a proper fabric name value:

z13 machine
FICON Express16S , MCL P08424.005 , LIC version 0x00000721
z14 machine
FICON Express16S , MCL P42611.008 , LIC version 0x10200069
FICON Express16S+ , MCL P42625.010 , LIC version 0x10300147

Otherwise, the read value is not the fabric name.

Each FCP channel of these card features might need one SAN fabric re-login
after concurrent microcode update in order to show the proper fabric name.
Possible ways to trigger a SAN fabric re-login are one of: Pull fibres
between FCP channel port and SAN switch port on either side and re-plug,
disable SAN switch port adjacent to FCP channel port and re-enable switch
port, or at Service Element toggle off all CHPIDs of FCP channel over all
LPARs and toggle CHPIDs on again. Zfcp operating subchannels (FCP devices)
on such FCP channel recovers a fabric re-login.

Initialize fabric name for any topology and have it an invalid WWPN 0x0 for
anything but fabric topology. Otherwise for e.g. point-to-point topology
one could see the initial -1 from fc_host_setup() and after a link unplug
our fabric name would turn to 0x0 (with subsequent commit ("zfcp: fix
fc_host attributes that should be unknown on local link down") and stay 0x0
on link replug. I did not initialize to 0x0 somewhere even earlier in the
code path such that it would not flap from real to 0x0 to real on e.g. an
exchange config data with fabric topology.

Link: https://lore.kernel.org/r/20200312174505.51294-3-maier@linux.ibm.com
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: zfcp: signal incomplete or error for sync exchange config/port data

Adds a new FSF-Request status flag (ZFCP_STATUS_FSFREQ_XDATAINCOMPLETE)
that signal that the data received using Exchange Config Data or Exchange
Port Data was incomplete. This new flags is set in the respective handlers
during the response path.

With this patch, only the synchronous FSF-functions for each command got
support for the new flag, otherwise it is transparent.

Together with this new flag and already existing status flags the
synchronous FSF-functions are extended to now detect whether the received
data is complete, incomplete or completely invalid (this includes cases
where a command ran into a timeout). This is now signaled back to the
caller, where previously only failures on the request path would result in
a bad return-code.

For complete data the return-code remains 0. For incomplete data a new
return-code -EAGAIN is added to the function-interface. For completely
invalid data the already existing return-code -EIO is reused - formerly
this was used to signal failures on the request path.

Existing callers of the FSF-functions are adjusted so that they behave as
before for return-code 0 and -EAGAIN, to not change the user-interface. As
-EIO existed all along, it was already exposed to the user - and needed
handling - and will now also be exposed in this new special case.

Link: https://lore.kernel.org/r/e14f0702fa2b00a4d1f37c7981a13f2dd1ea2c83.1572018130.git.bblock@linux.ibm.com
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: zfcp: fix to prevent port_remove with pure auto scan LUNs (only sdevs)

When the user tries to remove a zfcp port via sysfs, we only rejected it if
there are zfcp unit children under the port. With purely automatically
scanned LUNs there are no zfcp units but only SCSI devices. In such cases,
the port_remove erroneously continued. We close the port and this
implicitly closes all LUNs under the port. The SCSI devices survive with
their private zfcp_scsi_dev still holding a reference to the "removed"
zfcp_port (still allocated but invisible in sysfs) [zfcp_get_port_by_wwpn
in zfcp_scsi_slave_alloc]. This is not a problem as long as the fc_rport
stays blocked. Once (auto) port scan brings back the removed port, we
unblock its fc_rport again by design. However, there is no mechanism that
would recover (open) the LUNs under the port (no "ersfs_3" without
zfcp_unit [zfcp_erp_strategy_followup_success]). Any pending or new I/O to
such LUN leads to repeated:

Done: NEEDS_RETRY Result: hostbyte=DID_IMM_RETRY driverbyte=DRIVER_OK

See also v4.10 commit 6f2ce1c6af37 ("scsi: zfcp: fix rport unblock race
with LUN recovery"). Even a manual LUN recovery
(echo 0 > /sys/bus/scsi/devices/H:C:T:L/zfcp_failed)
does not help, as the LUN links to the old "removed" port which remains
to lack ZFCP_STATUS_COMMON_RUNNING [zfcp_erp_required_act].
The only workaround is to first ensure that the fc_rport is blocked
(e.g. port_remove again in case it was re-discovered by (auto) port scan),
then delete the SCSI devices, and finally re-discover by (auto) port scan.
The port scan includes an fc_rport unblock, which in turn triggers
a new scan on the scsi target to freshly get new pure auto scan LUNs.

Fix this by rejecting port_remove also if there are SCSI devices
(even without any zfcp_unit) under this port. Re-use mechanics from v3.7
commit d99b601b6338 ("[SCSI] zfcp: restore refcount check on port_remove").
However, we have to give up zfcp_sysfs_port_units_mutex earlier in unit_add
to prevent a deadlock with scsi_host scan taking shost->scan_mutex first
and then zfcp_sysfs_port_units_mutex now in our zfcp_scsi_slave_alloc().

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Fixes: b62a8d9b45b9 ("[SCSI] zfcp: Use SCSI device data zfcp scsi dev instead of zfcp unit")
Fixes: f8210e34887e ("[SCSI] zfcp: Allow midlayer to scan for LUNs when running in NPIV mode")
Cc: <stable@vger.kernel.org> #2.6.37+
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: zfcp: fix scsi_eh host reset with port_forced ERP for non-NPIV FCP devices

Suppose more than one non-NPIV FCP device is active on the same channel.
Send I/O to storage and have some of the pending I/O run into a SCSI
command timeout, e.g. due to bit errors on the fibre. Now the error
situation stops. However, we saw FCP requests continue to timeout in the
channel. The abort will be successful, but the subsequent TUR fails.
Scsi_eh starts. The LUN reset fails. The target reset fails. The host
reset only did an FCP device recovery. However, for non-NPIV FCP devices,
this does not close and reopen ports on the SAN-side if other non-NPIV FCP
device(s) share the same open ports.

In order to resolve the continuing FCP request timeouts, we need to
explicitly close and reopen ports on the SAN-side.

This was missing since the beginning of zfcp in v2.6.0 history commit
ea127f975424 ("[PATCH] s390 (7/7): zfcp host adapter.").

Note: The FSF requests for forced port reopen could run into FSF request
timeouts due to other reasons. This would trigger an internal FCP device
recovery. Pending forced port reopen recoveries would get dismissed. So
some ports might not get fully reopened during this host reset handler.
However, subsequent I/O would trigger the above described escalation and
eventually all ports would be forced reopen to resolve any continuing FCP
request timeouts due to earlier bit errors.

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: <stable@vger.kernel.org> #3.0+
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: zfcp: fix sysfs block queue limit output for max_segment_size

Since v2.6.35 commit 683229845f17 ("[SCSI] zfcp: Report scatter-gather
limits to SCSI and block layer"), zfcp set dma_parms.max_segment_size ==
PAGE_SIZE (but without using the setter dma_set_max_seg_size()) and
scsi_host_template.dma_boundary == PAGE_SIZE - 1.

v5.0-rc1 commit 50c2e9107f17 ("scsi: introduce a max_segment_size
host_template parameters") introduced a new field
scsi_host_template.max_segment_size. If an LLDD such as zfcp does not set
it, scsi_host_alloc() uses BLK_MAX_SEGMENT_SIZE = 65536 for
Scsi_Host.max_segment_size. __scsi_init_queue() announced the minimum of
Scsi_Host.max_segment_size and dma_parms.max_segment_size to the block
layer. For zfcp: min(65536, 4096) == 4096 which was still good.

v5.0 commit a8cf59a6692c ("scsi: communicate max segment size to the DMA
mapping code") announces Scsi_Host.max_segment_size to the block layer and
overwrites dma_parms.max_segment_size with Scsi_Host.max_segment_size. For
zfcp dma_parms.max_segment_size == Scsi_Host.max_segment_size == 65536
which is also reflected in block queue limits.

$ cd /sys/bus/ccw/drivers/zfcp
$ cd 0.0.3c40/host5/rport-5:0-4/target5:0:4/5:0:4:10/block/sdi/queue
$ cat max_segment_size
65536

Zfcp I/O still works because dma_boundary implicitly still keeps the
effective max segment size <= PAGE_SIZE. However, dma_boundary does not
seem visible to user space, but max_segment_size is visible and shows a
misleading wrong value. Fix it and inherit the stable tag of a8cf59a6692c.

Devices on our bus ccw support DMA but no DMA mapping. Of multiple device
types on the ccw bus, only zfcp needs dma_parms for SCSI limits. So, leave
dma_parms setup in zfcp and do not move it to the bus.

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Fixes: 50c2e9107f ("scsi: introduce a max_segment_size host_template parameters")
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: flip the default on use_clustering

Most SCSI drivers want to enable "clustering", that is merging of
segments so that they might span more than a single page. Remove the
ENABLE_CLUSTERING define, and require drivers to explicitly set
DISABLE_CLUSTERING to disable this feature.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: zfcp: make DIX experimental, disabled, and independent of DIF

Introduce separate zfcp module parameters to individually select support
for: DIF which should work (zfcp.dif, which used to be DIF+DIX, disabled)
or DIX+DIF which can cause trouble (zfcp.dix, new, disabled).

If DIX is enabled, we warn on zfcp driver initialization. As before, this
also reduces the maximum I/O request size to half, to support the worst
case of merged single sector requests with one protection data scatter
gather element per sector. This can impact the maximum throughput.

In DIF-only mode (zfcp.dif=1 zfcp.dix=0), we can use the full maximum I/O
request size as there is no protection data for zfcp.

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Fedor Loshakov <loshakov@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: zfcp: drop duplicate fsf_command from zfcp_fsf_req which is also in QTCB header

Status read buffers (SRBs, unsolicited notifications) never use a QTCB
[zfcp_fsf_req_create()]. zfcp_fsf_req_send() already uses this to
distinguish SRBs from other FSF request types. We can re-use this method in
zfcp_fsf_req_complete(). Introduce a helper function to make the check for
req->qtcb less magic.

SRBs always are FSF_QTCB_UNSOLICITED_STATUS, so we can hard-code this for
the two trace functions dealing with SRBs.

All other FSF request types have a QTCB and we can get the fsf_command from
there.

zfcp_dbf_hba_fsf_response() and thus zfcp_dbf_hba_fsf_res() are only called
for non-SRB requests so it's safe to dereference the QTCB
[zfcp_fsf_req_complete() returns early on SRB, else calls
zfcp_fsf_protstatus_eval() which calls zfcp_dbf_hba_fsf_response()]. In
zfcp_scsi_forget_cmnd() we guard the QTCB dereference with a preceding NULL
check and rely on boolean shortcut evaluation.

As a side effect, this causes an alignment hole which we can close in
a later patch after having cleaned up all fields of struct zfcp_fsf_req.
Before:
$ pahole -C zfcp_fsf_req drivers/s390/scsi/zfcp.ko
...
u32 status; /* 136 4 */
u32 fsf_command; /* 140 4 */
struct fsf_qtcb * qtcb; /* 144 8 */
...
After:
$ pahole -C zfcp_fsf_req drivers/s390/scsi/zfcp.ko
...
u32 status; /* 136 4 */
/* XXX 4 bytes hole, try to pack */
struct fsf_qtcb * qtcb; /* 144 8 */
...

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: zfcp: support SCSI_ADAPTER_RESET via scsi_host sysfs attribute host_reset

Make use of feature introduced with v3.2 commit 294436914454 ("[SCSI] scsi:
Added support for adapter and firmware reset"). The common code interface
was introduced for commit 95d31262b3c1 ("[SCSI] qla4xxx: Added support for
adapter and firmware reset").

$ echo adapter > /sys/class/scsi_host/host<N>/host_reset

Example trace record formatted with zfcpdbf from s390-tools:

Timestamp : ...
Area : REC
Subarea : 00
Level : 1
Exception : -
CPU ID : ..
Caller : 0x...
Record ID : 1 ZFCP_DBF_REC_TRIG
Tag : scshr_y SCSI sysfs host_reset yes
LUN : 0xffffffffffffffff none (invalid)
WWPN : 0x0000000000000000 none (invalid)
D_ID : 0x00000000 none (invalid)
Adapter status : 0x4500050b
Port status : 0x00000000 none (invalid)
LUN status : 0x00000000 none (invalid)
Ready count : 0x00000001
Running count : 0x00000000
ERP want : 0x04 ZFCP_ERP_ACTION_REOPEN_ADAPTER
ERP need : 0x04 ZFCP_ERP_ACTION_REOPEN_ADAPTER

This is the common code equivalent to the zfcp-specific
&dev_attr_adapter_failed.attr in zfcp_sysfs_adapter_attrs.attrs[]:

$ echo 0 > /sys/bus/ccw/drivers/zfcp/<devbusid>/failed

The unsupported case returns EOPNOTSUPP:

$ echo firmware > /sys/class/scsi_host/host<N>/host_reset
-bash: echo: write error: Operation not supported

Example trace record formatted with zfcpdbf from s390-tools:

Timestamp : ...
Area : SCSI
Subarea : 00
Level : 1
Exception : -
CPU ID : ..
Caller : 0x...
Record ID : 1
Tag : scshr_n SCSI sysfs host_reset no
Request ID : 0x0000000000000000 none (invalid)
SCSI ID : 0xffffffff none (invalid)
SCSI LUN : 0xffffffff none (invalid)
SCSI LUN high : 0xffffffff none (invalid)
SCSI result : 0xffffffa1 -EOPNOTSUPP==-95
SCSI retries : 0xff none (invalid)
SCSI allowed : 0xff none (invalid)
SCSI scribble : 0xffffffffffffffff none (invalid)
SCSI opcode : ffffffff ffffffff ffffffff ffffffff none (invalid)
FCP rsp inf cod: 0xff none (invalid)
FCP rsp IU : 00000000 00000000 00000000 00000000 none (invalid)
00000000 00000000

For any other invalid value, common code returns EINVAL without invoking
our callback:

$ echo foo > /sys/class/scsi_host/host<N>/host_reset
-bash: echo: write error: Invalid argument

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: zfcp: explicitly support initiator in scsi_host_template

While the default did already correctly print "Initiator" let's make it
explicit and convert zfcp to the feature.

$ cat /sys/class/scsi_host/host0/supported_mode
Initiator

$ cat /sys/class/scsi_host/host0/active_mode
Initiator

The default worked, because not setting the field has it initialized to zero
== MODE_UNKNOWN. scsi_host_alloc() sets shost->active_mode = MODE_INITIATOR
in this case. The sysfs accessor function show_shost_supported_mode()
assumes MODE_INITIATOR in this case. This default behavior was introduced
with v2.6.24 commit 7a39ac3f25be ("[SCSI] make supported_mode default to
initiator."). The feature flag was introduced with v2.6.24 commit
5dc2b89e1242 ("[SCSI] add supported_mode and active_mode attributes to the
host"). So there was no release where zfcp would have shown "unknown".

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: zfcp: consistently use function name space prefix

I've been mixing up
zfcp_task_mgmt_function() [SCSI] and
zfcp_fsf_fcp_task_mgmt() [FSF]
so often lately that I wanted to fix this.

SCSI changes complement v2.6.27 commit f76af7d7e363 ("[SCSI] zfcp: Cleanup
of code in zfcp_scsi.c").

While at it, also fixup the other inconsistencies elsewhere.

ERP changes complement v2.6.27 commit 287ac01acf22 ("[SCSI] zfcp: Cleanup
code in zfcp_erp.c") which introduced status_change_set().

FC changes complement v2.6.32 commit 6f53a2d2ecae ("[SCSI] zfcp: Apply
common naming conventions to zfcp_fc"). by renaming a leftover introduced
with v2.6.27 commit cc8c282963bd ("[SCSI] zfcp: Automatically attach remote
ports").

FSF changes fixup v2.6.32 commit a4623c467ff7 ("[SCSI] zfcp: Improve request
allocation through mempools"). which replaced zfcp_fsf_alloc_qtcb()
introduced with v2.6.27 commit c41f8cbddd4e ("[SCSI] zfcp: zfcp_fsf
cleanup.").

SCSI fc_host statistics were introduced with v2.6.16 commit f6cd94b126aa
("[SCSI] zfcp: transport class adaptations").

SCSI fc_host port_state was introduced with v2.6.27 commit 85a82392fe6f
("[SCSI] zfcp: Add port_state attribute to sysfs").

SCSI rport setter for dev_loss_tmo was introduced with v2.6.18 commit
338151e06608 ("[SCSI] zfcp: make use of fc_remote_port_delete when target
port is unavailable").

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: zfcp: workqueue: set description for port work items with their WWPN as context

As a prerequisite, complement commit 3d1cb2059d93 ("workqueue: include
workqueue info when printing debug dump of a worker task") to be usable with
kernel modules by exporting the symbol set_worker_desc(). Current built-in
user was introduced with commit ef3b101925f2 ("writeback: set worker desc to
identify writeback workers in task dumps").

Can help distinguishing work items which do not have adapter scope.
Description is printed out with task dump for debugging on WARN, BUG, panic,
or magic-sysrq [show-task-states(t)].

Example:
$ echo 0 >| /sys/bus/ccw/drivers/zfcp/0.0.1880/0x50050763031bd327/failed &
$ echo 't' >| /proc/sysrq-trigger
$ dmesg
sysrq: SysRq : Show State
task PC stack pid father
...
zfcp_q_0.0.1880 S14640 2165 2 0x02000000
Call Trace:
([<00000000009df464>] __schedule+0xbf4/0xc78)
[<00000000009df57c>] schedule+0x94/0xc0
[<0000000000168654>] rescuer_thread+0x33c/0x3a0
[<000000000016f8be>] kthread+0x166/0x178
[<00000000009e71f2>] kernel_thread_starter+0x6/0xc
[<00000000009e71ec>] kernel_thread_starter+0x0/0xc
no locks held by zfcp_q_0.0.1880/2165.
...
kworker/u512:2 D11280 2193 2 0x02000000
Workqueue: zfcp_q_0.0.1880 zfcp_scsi_rport_work [zfcp] (zrpd-50050763031bd327)
^^^^^^^^^^^^^^^^^^^^^
Call Trace:
([<00000000009df464>] __schedule+0xbf4/0xc78)
[<00000000009df57c>] schedule+0x94/0xc0
[<00000000009e50c0>] schedule_timeout+0x488/0x4d0
[<00000000001e425c>] msleep+0x5c/0x78 >>test code only<<
[<000003ff8008a21e>] zfcp_scsi_rport_work+0xbe/0x100 [zfcp]
[<0000000000167154>] process_one_work+0x3b4/0x718
[<000000000016771c>] worker_thread+0x264/0x408
[<000000000016f8be>] kthread+0x166/0x178
[<00000000009e71f2>] kernel_thread_starter+0x6/0xc
[<00000000009e71ec>] kernel_thread_starter+0x0/0xc
2 locks held by kworker/u512:2/2193:
#0: (name){++++.+}, at: [<0000000000166f4e>] process_one_work+0x1ae/0x718
#1: ((&(&port->rport_work)->work)){+.+.+.}, at: [<0000000000166f4e>] process_one_work+0x1ae/0x718
...

=============================================
Showing busy workqueues and worker pools:
workqueue zfcp_q_0.0.1880: flags=0x2000a
pwq 512: cpus=0-255 flags=0x4 nice=0 active=1/1
in-flight: 2193:zfcp_scsi_rport_work [zfcp]
pool 512: cpus=0-255 flags=0x4 nice=0 hung=0s workers=4 idle: 5 2354 2311

Work items with adapter scope are already identified by the workqueue name
"zfcp_q_<devbusid>" and the work item function name.

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: zfcp: decouple our scsi_eh callbacks from scsi_cmnd

Note: zfcp_scsi_eh_host_reset_handler() will be converted in a later patch.

zfcp_scsi_eh_device_reset_handler() now only depends on scsi_device.
zfcp_scsi_eh_target_reset_handler() now only depends on scsi_target.
All derive other objects from these intended callback arguments.

zfcp_scsi_eh_target_reset_handler() is special: The FCP channel requires a
valid LUN handle so we try to find ourselves a stand-in scsi_device as
suggested by Hannes Reinecke. If it cannot find a stand-in scsi device,
trace a record like the following (formatted with zfcpdbf from s390-tools):

Timestamp : ...
Area : SCSI
Subarea : 00
Level : 1
Exception : -
CPU ID : ..
Caller : 0x...
Record ID : 1
Tag : tr_nosd target reset, no SCSI device
Request ID : 0x0000000000000000 none (invalid)
SCSI ID : 0x00000000 SCSI ID/target denoting scope
SCSI LUN : 0xffffffff none (invalid)
SCSI LUN high : 0xffffffff none (invalid)
SCSI result : 0x00002003 field re-used for midlayer value: FAILED
SCSI retries : 0xff none (invalid)
SCSI allowed : 0xff none (invalid)
SCSI scribble : 0xffffffffffffffff none (invalid)
SCSI opcode : ffffffff ffffffff ffffffff ffffffff none (invalid)
FCP rsp inf cod: 0xff none (invalid)
FCP rsp IU : 00000000 00000000 00000000 00000000 none (invalid)
00000000 00000000

Actually change the signature of zfcp_task_mgmt_function() used by
zfcp_scsi_eh_device_reset_handler() & zfcp_scsi_eh_target_reset_handler().
Since it was prepared in a previous patch, we only need to delete a local
auto variable which is now the intended argument.

Suggested-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: zfcp: decouple TMFs from scsi_cmnd by using fc_block_rport

Intentionally retrieve the rport by walking SCSI common code objects
rather than zfcp_sdev->port->rport.

The latter is used for pairing the calls to fc_remote_port_add() and
fc_remote_port_delete(). [see v2.6.31 commit 379d6bf6573e ("[SCSI] zfcp:
Add port only once to FC transport class")]

zfcp_scsi_rport_register() sets zfcp_port.rport to what
fc_remote_port_add() returned.
zfcp_scsi_rport_block() sets zfcp_port.rport = NULL after having called
fc_remote_port_delete().

Hence, while an rport is blocked (or in any subsequent state due to
scsi_transport_fc timeouts such as fast_io_fail_tmo or dev_loss_tmo),
zfcp_port.rport is NULL and cannot serve as argument to fc_block_rport().

During zfcp recovery, a just recovered zfcp_port can have the UNBLOCKED
status flag, but an async rport unblocking has only started via
zfcp_scsi_schedule_rport_register() in zfcp_erp_try_rport_unblock()
[see v4.10 commit 6f2ce1c6af37 ("scsi: zfcp: fix rport unblock race with
LUN recovery")] in zfcp_erp_action_cleanup(). Now zfcp_erp_wait() can
return. This would be sufficient to successfully send a TMF.
But the rport can still be blocked and zfcp_port.rport can still be NULL
until zfcp_port.rport_work was scheduled and has actually called
fc_remote_port_add() and assigned its return value to zfcp_port.rport.
We need an unblocked rport for a successful scsi_eh TUR.

Similarly, for a zfcp_port which has just lost its UNBLOCKED status flag,
the return of zfcp_erp_wait() can race with zfcp_port.rport_work queued
by zfcp_scsi_schedule_rport_block(). Therefore we cannot reliably access
zfcp_port.rport. However, we'd like to get fc_rport_block()'s opinion on
when fast_io_fail_tmo triggered. While we might use
flush_work(&port->rport_work) to sync with the work item, we can simply use
the other way to get an rport pointer.

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: zfcp: decouple SCSI setup of TMF from scsi_cmnd

Actually change the signature of zfcp_fsf_fcp_task_mgmt().
Since it was prepared in the previous patch, we only need to delete
a local auto variable which is now the intended argument.

Prepare zfcp_fsf_fcp_task_mgmt's caller zfcp_task_mgmt_function()
to have its function body only depend on a scsi_device and derived objects.

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: zfcp: decouple SCSI traces for scsi_eh / TMF from scsi_cmnd

The SCSI command pointer passed to scsi_eh callbacks is just one arbitrary
command of potentially many that are in the eh queue to be processed. The
command is only used to indirectly pass the TMF scope in terms of SCSI
ID/target and SCSI LUN for LUN reset.

Hence, zfcp had filled in SCSI trace record fields which do not really
belong to the TMF. This was confusing.

Therefore, refactor the TMF tracing to work without SCSI command. Since the
FCP channel always requires a valid LUN handle, we use SCSI device as common
context for any TMF (even target reset). To make it even clearer, we set
all bits to 1 for the fields, which do not belong to the TMF, to indicate
that these fields are invalid.

The old zfcp_dbf_scsi() became zfcp_dbf_scsi_common() to now handle both
SCSI commands and TMFs. The old argument scsi_cmnd is now optional and can
be NULL with TMFs. The new argument scsi_device is mandatory to carry
context, as well as SCSI ID/target and SCSI LUN in case of TMFs.

New example trace record formatted with zfcpdbf from s390-tools:

Timestamp : ...
Area : SCSI
Subarea : 00
Level : 1
Exception : -
CPU ID : ..
Caller : 0x...
Record ID : 1
Tag : [lt]r_....
Request ID : 0x<reqid> ID of FSF FCP request with TM flag
For cases without FSF request: 0x0 for none (invalid)
SCSI ID : 0x<scsi_id> SCSI ID/target denoting scope
SCSI LUN : 0x<scsi_lun> SCSI LUN denoting scope
SCSI LUN high : 0x<scsi_lun_high> SCSI LUN denoting scope
SCSI result : 0xffffffff none (invalid)
SCSI retries : 0xff none (invalid)
SCSI allowed : 0xff none (invalid)
SCSI scribble : 0xffffffffffffffff none (invalid)
SCSI opcode : ffffffff ffffffff ffffffff ffffffff none (invalid)
FCP rsp inf cod: 0x00 FCP_RSP info code of TMF
FCP rsp IU : 00000000 00000000 00000100 00000000 ext FCP_RSP IU
00000000 00000008 ext FCP_RSP IU
FCP rsp IU len : 32 FCP_RSP IU length
Payload time : ...
FCP rsp IU all : 00000000 00000000 00000100 00000000 full FCP_RSP IU
00000000 00000008 00000000 00000000 full FCP_RSP IU

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: zfcp: fix missing REC trigger trace on terminate_rport_io early return

get_device() and its internally used kobject_get() only return NULL if they
get passed NULL as argument. zfcp_get_port_by_wwpn() loops over
adapter->port_list so the iteration variable port is always non-NULL.
Struct device is embedded in struct zfcp_port so &port->dev is always
non-NULL. This is the argument to get_device(). However, if we get an
fc_rport in terminate_rport_io() for which we cannot find a match within
zfcp_get_port_by_wwpn(), the latter can return NULL. v2.6.30 commit
70932935b61e ("[SCSI] zfcp: Fix oops when port disappears") introduced an
early return without adding a trace record for this case. Even if we don't
need recovery in this case, for debugging we should still see that our
callback was invoked originally by scsi_transport_fc.

Example trace record formatted with zfcpdbf from s390-tools:

Timestamp : ...
Area : REC
Subarea : 00
Level : 1
Exception : -
CPU ID : ..
Caller : 0x...
Record ID : 1
Tag : sctrpin SCSI terminate rport I/O, no zfcp port
LUN : 0xffffffffffffffff none (invalid)
WWPN : 0x<wwpn> WWPN
D_ID : 0x<n_port_id> N_Port-ID
Adapter status : 0x...
Port status : 0xffffffff unknown (-1)
LUN status : 0x00000000 none (invalid)
Ready count : 0x...
Running count : 0x...
ERP want : 0x03 ZFCP_ERP_ACTION_REOPEN_PORT_FORCED
ERP need : 0xc0 ZFCP_ERP_ACTION_NONE

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Fixes: 70932935b61e ("[SCSI] zfcp: Fix oops when port disappears")
Cc: <stable@vger.kernel.org> #2.6.38+
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: zfcp: fix missing SCSI trace for retry of abort / scsi_eh TMF

We already have a SCSI trace for the end of abort and scsi_eh TMF. Due to
zfcp_erp_wait() and fc_block_scsi_eh() time can pass between the start of
our eh callback and an actual send/recv of an abort / TMF request. In order
to see the temporal sequence including any abort / TMF send retries, add a
trace before the above two blocking functions. This supports problem
determination with scsi_eh and parallel zfcp ERP.

No need to explicitly trace the beginning of our eh callback, since we
typically can send an abort / TMF and see its HBA response (in the worst
case, it's a pseudo response on dismiss all of adapter recovery, e.g. due to
an FSF request timeout [fsrth_1] of the abort / TMF). If we cannot send, we
now get a trace record for the first "abrt_wt" or "[lt]r_wait" which denotes
almost the beginning of the callback.

No need to explicitly trace the wakeup after the above two blocking
functions because the next retry loop causes another trace in any case and
that is sufficient.

Example trace records formatted with zfcpdbf from s390-tools:

Timestamp : ...
Area : SCSI
Subarea : 00
Level : 1
Exception : -
CPU ID : ..
Caller : 0x...
Record ID : 1
Tag : abrt_wt abort, before zfcp_erp_wait()
Request ID : 0x0000000000000000 none (invalid)
SCSI ID : 0x<scsi_id>
SCSI LUN : 0x<scsi_lun>
SCSI LUN high : 0x<scsi_lun_high>
SCSI result : 0x<scsi_result_of_cmd_to_be_aborted>
SCSI retries : 0x<retries_of_cmd_to_be_aborted>
SCSI allowed : 0x<allowed_retries_of_cmd_to_be_aborted>
SCSI scribble : 0x<req_id_of_cmd_to_be_aborted>
SCSI opcode : <CDB_of_cmd_to_be_aborted>
FCP rsp inf cod: 0x.. none (invalid)
FCP rsp IU : ... none (invalid)

Timestamp : ...
Area : SCSI
Subarea : 00
Level : 1
Exception : -
CPU ID : ..
Caller : 0x...
Record ID : 1
Tag : lr_wait LUN reset, before zfcp_erp_wait()
Request ID : 0x0000000000000000 none (invalid)
SCSI ID : 0x<scsi_id>
SCSI LUN : 0x<scsi_lun>
SCSI LUN high : 0x<scsi_lun_high>
SCSI result : 0x... unrelated
SCSI retries : 0x.. unrelated
SCSI allowed : 0x.. unrelated
SCSI scribble : 0x... unrelated
SCSI opcode : ... unrelated
FCP rsp inf cod: 0x.. none (invalid)
FCP rsp IU : ... none (invalid)

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Fixes: 63caf367e1c9 ("[SCSI] zfcp: Improve reliability of SCSI eh handlers in zfcp")
Fixes: af4de36d911a ("[SCSI] zfcp: Block scsi_eh thread for rport state BLOCKED")
Cc: <stable@vger.kernel.org> #2.6.38+
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: zfcp: fix missing SCSI trace for result of eh_host_reset_handler

For problem determination we need to see whether and why we were successful
or not. This allows deduction of scsi_eh escalation.

Example trace record formatted with zfcpdbf from s390-tools:

Timestamp : ...
Area : SCSI
Subarea : 00
Level : 1
Exception : -
CPU ID : ..
Caller : 0x...
Record ID : 1
Tag : schrh_r SCSI host reset handler result
Request ID : 0x0000000000000000 none (invalid)
SCSI ID : 0xffffffff none (invalid)
SCSI LUN : 0xffffffff none (invalid)
SCSI LUN high : 0xffffffff none (invalid)
SCSI result : 0x00002002 field re-used for midlayer value: SUCCESS
or in other cases: 0x2009 == FAST_IO_FAIL
SCSI retries : 0xff none (invalid)
SCSI allowed : 0xff none (invalid)
SCSI scribble : 0xffffffffffffffff none (invalid)
SCSI opcode : ffffffff ffffffff ffffffff ffffffff none (invalid)
FCP rsp inf cod: 0xff none (invalid)
FCP rsp IU : 00000000 00000000 00000000 00000000 none (invalid)
00000000 00000000

v2.6.35 commit a1dbfddd02d2 ("[SCSI] zfcp: Pass return code from
fc_block_scsi_eh to scsi eh") introduced the first return with something
other than the previously hardcoded single SUCCESS return path.

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Fixes: a1dbfddd02d2 ("[SCSI] zfcp: Pass return code from fc_block_scsi_eh to scsi eh")
Cc: <stable@vger.kernel.org> #2.6.38+
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: zfcp: fix infinite iteration on ERP ready list

zfcp_erp_adapter_reopen() schedules blocking of all of the adapter's
rports via zfcp_scsi_schedule_rports_block() and enqueues a reopen
adapter ERP action via zfcp_erp_action_enqueue(). Both are separately
processed asynchronously and concurrently.

Blocking of rports is done in a kworker by zfcp_scsi_rport_work(). It
calls zfcp_scsi_rport_block(), which then traces a DBF REC "scpdely" via
zfcp_dbf_rec_trig(). zfcp_dbf_rec_trig() acquires the DBF REC spin lock
and then iterates with list_for_each() over the adapter's ERP ready list
without holding the ERP lock. This opens a race window in which the
current list entry can be moved to another list, causing list_for_each()
to iterate forever on the wrong list, as the erp_ready_head is never
encountered as terminal condition.

Meanwhile the ERP action can be processed in the ERP thread by
zfcp_erp_thread(). It calls zfcp_erp_strategy(), which acquires the ERP
lock and then calls zfcp_erp_action_to_running() to move the ERP action
from the ready to the running list. zfcp_erp_action_to_running() can
move the ERP action using list_move() just during the aforementioned
race window. It then traces a REC RUN "erator1" via zfcp_dbf_rec_run().
zfcp_dbf_rec_run() tries to acquire the DBF REC spin lock. If this is
held by the infinitely looping kworker, it effectively spins forever.

Example Sequence Diagram:

Process ERP Thread rport_work
------------------- ------------------- -------------------
zfcp_erp_adapter_reopen()
zfcp_erp_adapter_block()
zfcp_scsi_schedule_rports_block()
lock ERP zfcp_scsi_rport_work()
zfcp_erp_action_enqueue(ZFCP_ERP_ACTION_REOPEN_ADAPTER)
list_add_tail() on ready !(rport_task==RPORT_ADD)
wake_up() ERP thread zfcp_scsi_rport_block()
zfcp_dbf_rec_trig() zfcp_erp_strategy() zfcp_dbf_rec_trig()
unlock ERP lock DBF REC
zfcp_erp_wait() lock ERP
| zfcp_erp_action_to_running()
| list_for_each() ready
| list_move() current entry
| ready to running
| zfcp_dbf_rec_run() endless loop over running
| zfcp_dbf_rec_run_lvl()
| lock DBF REC spins forever

Any adapter recovery can trigger this, such as setting the device offline
or reboot.

V4.9 commit 4eeaa4f3f1d6 ("zfcp: close window with unblocked rport
during rport gone") introduced additional tracing of (un)blocking of
rports. It missed that the adapter->erp_lock must be held when calling
zfcp_dbf_rec_trig().

This fix uses the approach formerly introduced by commit aa0fec62391c
("[SCSI] zfcp: Fix sparse warning by providing new entry in dbf") that got
later removed by commit ae0904f60fab ("[SCSI] zfcp: Redesign of the debug
tracing for recovery actions.").

Introduce zfcp_dbf_rec_trig_lock(), a wrapper for zfcp_dbf_rec_trig() that
acquires and releases the adapter->erp_lock for read.

Reported-by: Sebastian Ott <sebott@linux.ibm.com>
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
Fixes: 4eeaa4f3f1d6 ("zfcp: close window with unblocked rport during rport gone")
Cc: <stable@vger.kernel.org> # 2.6.32+
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

scsi: zfcp: fix erp_action use-before-initialize in REC action trace

v4.10 commit 6f2ce1c6af37 ("scsi: zfcp: fix rport unblock race with LUN
recovery") extended accessing parent pointer fields of struct
zfcp_erp_action for tracing. If an erp_action has never been enqueued
before, these parent pointer fields are uninitialized and NULL. Examples
are zfcp objects freshly added to the parent object's children list,
before enqueueing their first recovery subsequently. In
zfcp_erp_try_rport_unblock(), we iterate such list. Accessing erp_action
fields can cause a NULL pointer dereference. Since the kernel can read
from lowcore on s390, it does not immediately cause a kernel page
fault. Instead it can cause hangs on trying to acquire the wrong
erp_action->adapter->dbf->rec_lock in zfcp_dbf_rec_action_lvl()
^bogus^
while holding already other locks with IRQs disabled.

Real life example from attaching lots of LUNs in parallel on many CPUs:

crash> bt 17723
PID: 17723 TASK: ... CPU: 25 COMMAND: "zfcperp0.0.1800"
LOWCORE INFO:
-psw : 0x0404300180000000 0x000000000038e424
-function : _raw_spin_lock_wait_flags at 38e424
...
#0 [fdde8fc90] zfcp_dbf_rec_action_lvl at 3e0004e9862 [zfcp]
#1 [fdde8fce8] zfcp_erp_try_rport_unblock at 3e0004dfddc [zfcp]
#2 [fdde8fd38] zfcp_erp_strategy at 3e0004e0234 [zfcp]
#3 [fdde8fda8] zfcp_erp_thread at 3e0004e0a12 [zfcp]
#4 [fdde8fe60] kthread at 173550
#5 [fdde8feb8] kernel_thread_starter at 10add2

zfcp_adapter
zfcp_port
zfcp_unit <address>, 0x404040d600000000
scsi_device NULL, returning early!
zfcp_scsi_dev.status = 0x40000000
0x40000000 ZFCP_STATUS_COMMON_RUNNING

crash> zfcp_unit <address>
struct zfcp_unit {
erp_action = {
adapter = 0x0,
port = 0x0,
unit = 0x0,
},
}

zfcp_erp_action is always fully embedded into its container object. Such
container object is never moved in its object tree (only add or delete).
Hence, erp_action parent pointers can never change.

To fix the issue, initialize the erp_action parent pointers before
adding the erp_action container to any list and thus before it becomes
accessible from outside of its initializing function.

In order to also close the time window between zfcp_erp_setup_act()
memsetting the entire erp_action to zero and setting the parent pointers
again, drop the memset and instead explicitly initialize individually
all erp_action fields except for parent pointers. To be extra careful
not to introduce any other unintended side effect, even keep zeroing the
erp_action fields for list and timer. Also double-check with
WARN_ON_ONCE that erp_action parent pointers never change, so we get to
know when we would deviate from previous behavior.

Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Fixes: 6f2ce1c6af37 ("scsi: zfcp: fix rport unblock race with LUN recovery")
Cc: <stable@vger.kernel.org> #2.6.32+
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: zfcp: fix missing trace records for early returns in TMF eh handlers

For problem determination we need to see that we were in scsi_eh
as well as whether and why we were successful or not.

The following commits introduced new early returns without adding
a trace record:

v2.6.35 commit a1dbfddd02d2
("[SCSI] zfcp: Pass return code from fc_block_scsi_eh to scsi eh")
on fc_block_scsi_eh() returning != 0 which is FAST_IO_FAIL,

v2.6.30 commit 63caf367e1c9
("[SCSI] zfcp: Improve reliability of SCSI eh handlers in zfcp")
on not having gotten an FSF request after the maximum number of retry
attempts and thus could not issue a TMF and has to return FAILED.

Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Fixes: a1dbfddd02d2 ("[SCSI] zfcp: Pass return code from fc_block_scsi_eh to scsi eh")
Fixes: 63caf367e1c9 ("[SCSI] zfcp: Improve reliability of SCSI eh handlers in zfcp")
Cc: <stable@vger.kernel.org> #2.6.38+
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: zfcp: fix passing fsf_req to SCSI trace on TMF to correlate with HBA

Without this fix we get SCSI trace records on task management functions
which cannot be correlated to HBA trace records because all fields
related to the FSF request are empty (zero).
Also, the FCP_RSP_IU is missing as well as any sense data if available.

This was caused by v2.6.14 commit 8a36e4532ea1 ("[SCSI] zfcp: enhancement
of zfcp debug features") introducing trace records for TMFs but
hard coding NULL for a possibly existing TMF FSF request.
The scsi_cmnd scribble is also zero or unrelated for the TMF request
so it also could not lookup a suitable FSF request from there.

A broken example trace record formatted with zfcpdbf from the s390-tools
package:

Timestamp : ...
Area : SCSI
Subarea : 00
Level : 1
Exception : -
CPU ID : ..
Caller : 0x...
Record ID : 1
Tag : lr_fail
Request ID : 0x0000000000000000
^^^^^^^^^^^^^^^^ no correlation to HBA record
SCSI ID : 0x<scsitarget>
SCSI LUN : 0x<scsilun>
SCSI result : 0x000e0000
SCSI retries : 0x00
SCSI allowed : 0x05
SCSI scribble : 0x0000000000000000
SCSI opcode : 2a000017 3bb80000 08000000 00000000
FCP rsp inf cod: 0x00
^^ no TMF response
FCP rsp IU : 00000000 00000000 00000000 00000000
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
00000000 00000000
^^^^^^^^^^^^^^^^^ no interesting FCP_RSP_IU
Sense len : ...
^^^^^^^^^^^^^^^^^^^^ no sense data length
Sense info : ...
^^^^^^^^^^^^^^^^^^^^ no sense data content, even if present

There are some true cases where we really do not have an FSF request:
"rsl_fai" from zfcp_dbf_scsi_fail_send() called for early
returns / completions in zfcp_scsi_queuecommand(),
"abrt_or", "abrt_bl", "abrt_ru", "abrt_ar" from
zfcp_scsi_eh_abort_handler() where we did not get as far,
"lr_nres", "tr_nres" from zfcp_task_mgmt_function() where we're
successful and do not need to do anything because adapter stopped.
For these cases it's correct to pass NULL for fsf_req to _zfcp_dbf_scsi().

Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Fixes: 8a36e4532ea1 ("[SCSI] zfcp: enhancement of zfcp debug features")
Cc: <stable@vger.kernel.org> #2.6.38+
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: zfcp: convert bool-definitions to use 'true' instead of '1'

Better form and cleans remaining warnings.

Found with scripts/coccinelle/misc/boolinit.cocci.

Signed-off-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: remove eh_timed_out methods in the transport template

Instead define the timeout behavior purely based on the host_template
eh_timed_out method and wire up the existing transport implementations
in the host templates. This also clears up the confusion that the
transport template method overrides the host template one, so some
drivers have to re-override the transport template one.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: zfcp: fix rport unblock race with LUN recovery

It is unavoidable that zfcp_scsi_queuecommand() has to finish requests
with DID_IMM_RETRY (like fc_remote_port_chkready()) during the time
window when zfcp detected an unavailable rport but
fc_remote_port_delete(), which is asynchronous via
zfcp_scsi_schedule_rport_block(), has not yet blocked the rport.

However, for the case when the rport becomes available again, we should
prevent unblocking the rport too early. In contrast to other FCP LLDDs,
zfcp has to open each LUN with the FCP channel hardware before it can
send I/O to a LUN. So if a port already has LUNs attached and we
unblock the rport just after port recovery, recoveries of LUNs behind
this port can still be pending which in turn force
zfcp_scsi_queuecommand() to unnecessarily finish requests with
DID_IMM_RETRY.

This also opens a time window with unblocked rport (until the followup
LUN reopen recovery has finished). If a scsi_cmnd timeout occurs during
this time window fc_timed_out() cannot work as desired and such command
would indeed time out and trigger scsi_eh. This prevents a clean and
timely path failover. This should not happen if the path issue can be
recovered on FC transport layer such as path issues involving RSCNs.

Fix this by only calling zfcp_scsi_schedule_rport_register(), to
asynchronously trigger fc_remote_port_add(), after all LUN recoveries as
children of the rport have finished and no new recoveries of equal or
higher order were triggered meanwhile. Finished intentionally includes
any recovery result no matter if successful or failed (still unblock
rport so other successful LUNs work). For simplicity, we check after
each finished LUN recovery if there is another LUN recovery pending on
the same port and then do nothing. We handle the special case of a
successful recovery of a port without LUN children the same way without
changing this case's semantics.

For debugging we introduce 2 new trace records written if the rport
unblock attempt was aborted due to still unfinished or freshly triggered
recovery. The records are only written above the default trace level.

Benjamin noticed the important special case of new recovery that can be
triggered between having given up the erp_lock and before calling
zfcp_erp_action_cleanup() within zfcp_erp_strategy(). We must avoid the
following sequence:

ERP thread rport_work other context
------------------------- -------------- --------------------------------
port is unblocked, rport still blocked,
due to pending/running ERP action,
so ((port->status & ...UNBLOCK) != 0)
and (port->rport == NULL)
unlock ERP
zfcp_erp_action_cleanup()
case ZFCP_ERP_ACTION_REOPEN_LUN:
zfcp_erp_try_rport_unblock()
((status & ...UNBLOCK) != 0) [OLD!]
zfcp_erp_port_reopen()
lock ERP
zfcp_erp_port_block()
port->status clear ...UNBLOCK
unlock ERP
zfcp_scsi_schedule_rport_block()
port->rport_task = RPORT_DEL
queue_work(rport_work)
zfcp_scsi_rport_work()
(port->rport_task != RPORT_ADD)
port->rport_task = RPORT_NONE
zfcp_scsi_rport_block()
if (!port->rport) return
zfcp_scsi_schedule_rport_register()
port->rport_task = RPORT_ADD
queue_work(rport_work)
zfcp_scsi_rport_work()
(port->rport_task == RPORT_ADD)
port->rport_task = RPORT_NONE
zfcp_scsi_rport_register()
(port->rport == NULL)
rport = fc_remote_port_add()
port->rport = rport;

Now the rport was erroneously unblocked while the zfcp_port is blocked.
This is another situation we want to avoid due to scsi_eh
potential. This state would at least remain until the new recovery from
the other context finished successfully, or potentially forever if it
failed. In order to close this race, we take the erp_lock inside
zfcp_erp_try_rport_unblock() when checking the status of zfcp_port or
LUN. With that, the possible corresponding rport state sequences would
be: (unblock[ERP thread],block[other context]) if the ERP thread gets
erp_lock first and still sees ((port->status & ...UNBLOCK) != 0),
(block[other context],NOP[ERP thread]) if the ERP thread gets erp_lock
after the other context has already cleard ...UNBLOCK from port->status.

Since checking fields of struct erp_action is unsafe because they could
have been overwritten (re-used for new recovery) meanwhile, we only
check status of zfcp_port and LUN since these are only changed under
erp_lock elsewhere. Regarding the check of the proper status flags (port
or port_forced are similar to the shown adapter recovery):

[zfcp_erp_adapter_shutdown()]
zfcp_erp_adapter_reopen()
zfcp_erp_adapter_block()
* clear UNBLOCK ---------------------------------------+
zfcp_scsi_schedule_rports_block() |
write_lock_irqsave(&adapter->erp_lock, flags);-------+ |
zfcp_erp_action_enqueue() | |
zfcp_erp_setup_act() | |
* set ERP_INUSE -----------------------------------|--|--+
write_unlock_irqrestore(&adapter->erp_lock, flags);--+ | |
.context-switch. | |
zfcp_erp_thread() | |
zfcp_erp_strategy() | |
write_lock_irqsave(&adapter->erp_lock, flags);------+ | |
... | | |
zfcp_erp_strategy_check_target() | | |
zfcp_erp_strategy_check_adapter() | | |
zfcp_erp_adapter_unblock() | | |
* set UNBLOCK -----------------------------------|--+ |
zfcp_erp_action_dequeue() | |
* clear ERP_INUSE ---------------------------------|-----+
... |
write_unlock_irqrestore(&adapter->erp_lock, flags);-+

Hence, we should check for both UNBLOCK and ERP_INUSE because they are
interleaved. Also we need to explicitly check ERP_FAILED for the link
down case which currently does not clear the UNBLOCK flag in
zfcp_fsf_link_down_info_eval().

Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Fixes: 8830271c4819 ("[SCSI] zfcp: Dont fail SCSI commands when transitioning to blocked fc_rport")
Fixes: a2fa0aede07c ("[SCSI] zfcp: Block FC transport rports early on errors")
Fixes: 5f852be9e11d ("[SCSI] zfcp: Fix deadlock between zfcp ERP and SCSI")
Fixes: 338151e06608 ("[SCSI] zfcp: make use of fc_remote_port_delete when target port is unavailable")
Fixes: 3859f6a248cb ("[PATCH] zfcp: add rports to enable scsi_add_device to work again")
Cc: <stable@vger.kernel.org> #2.6.32+
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: zfcp: fix use-after-"free" in FC ingress path after TMF

When SCSI EH invokes zFCP's callbacks for eh_device_reset_handler() and
eh_target_reset_handler(), it expects us to relent the ownership over
the given scsi_cmnd and all other scsi_cmnds within the same scope - LUN
or target - when returning with SUCCESS from the callback ('release'
them). SCSI EH can then reuse those commands.

We did not follow this rule to release commands upon SUCCESS; and if
later a reply arrived for one of those supposed to be released commands,
we would still make use of the scsi_cmnd in our ingress tasklet. This
will at least result in undefined behavior or a kernel panic because of
a wrong kernel pointer dereference.

To fix this, we NULLify all pointers to scsi_cmnds (struct zfcp_fsf_req
*)->data in the matching scope if a TMF was successful. This is done
under the locks (struct zfcp_adapter *)->abort_lock and (struct
zfcp_reqlist *)->lock to prevent the requests from being removed from
the request-hashtable, and the ingress tasklet from making use of the
scsi_cmnd-pointer in zfcp_fsf_fcp_cmnd_handler().

For cases where a reply arrives during SCSI EH, but before we get a
chance to NULLify the pointer - but before we return from the callback
-, we assume that the code is protected from races via the CAS operation
in blk_complete_request() that is called in scsi_done().

The following stacktrace shows an example for a crash resulting from the
previous behavior:

Unable to handle kernel pointer dereference at virtual kernel address fffffee17a672000
Oops: 0038 [#1] SMP
CPU: 2 PID: 0 Comm: swapper/2 Not tainted
task: 00000003f7ff5be0 ti: 00000003f3d38000 task.ti: 00000003f3d38000
Krnl PSW : 0404d00180000000 00000000001156b0 (smp_vcpu_scheduled+0x18/0x40)
R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:3 CC:1 PM:0 EA:3
Krnl GPRS: 000000200000007e 0000000000000000 fffffee17a671fd8 0000000300000015
ffffffff80000000 00000000005dfde8 07000003f7f80e00 000000004fa4e800
000000036ce8d8f8 000000036ce8d9c0 00000003ece8fe00 ffffffff969c9e93
00000003fffffffd 000000036ce8da10 00000000003bf134 00000003f3b07918
Krnl Code: 00000000001156a2: a7190000 lghi %r1,0
00000000001156a6: a7380015 lhi %r3,21
#00000000001156aa: e32050000008 ag %r2,0(%r5)
>00000000001156b0: 482022b0 lh %r2,688(%r2)
00000000001156b4: ae123000 sigp %r1,%r2,0(%r3)
00000000001156b8: b2220020 ipm %r2
00000000001156bc: 8820001c srl %r2,28
00000000001156c0: c02700000001 xilf %r2,1
Call Trace:
([<0000000000000000>] 0x0)
[<000003ff807bdb8e>] zfcp_fsf_fcp_cmnd_handler+0x3de/0x490 [zfcp]
[<000003ff807be30a>] zfcp_fsf_req_complete+0x252/0x800 [zfcp]
[<000003ff807c0a48>] zfcp_fsf_reqid_check+0xe8/0x190 [zfcp]
[<000003ff807c194e>] zfcp_qdio_int_resp+0x66/0x188 [zfcp]
[<000003ff80440c64>] qdio_kick_handler+0xdc/0x310 [qdio]
[<000003ff804463d0>] __tiqdio_inbound_processing+0xf8/0xcd8 [qdio]
[<0000000000141fd4>] tasklet_action+0x9c/0x170
[<0000000000141550>] __do_softirq+0xe8/0x258
[<000000000010ce0a>] do_softirq+0xba/0xc0
[<000000000014187c>] irq_exit+0xc4/0xe8
[<000000000046b526>] do_IRQ+0x146/0x1d8
[<00000000005d6a3c>] io_return+0x0/0x8
[<00000000005d6422>] vtime_stop_cpu+0x4a/0xa0
([<0000000000000000>] 0x0)
[<0000000000103d8a>] arch_cpu_idle+0xa2/0xb0
[<0000000000197f94>] cpu_startup_entry+0x13c/0x1f8
[<0000000000114782>] smp_start_secondary+0xda/0xe8
[<00000000005d6efe>] restart_int_handler+0x56/0x6c
[<0000000000000000>] 0x0
Last Breaking-Event-Address:
[<00000000003bf12e>] arch_spin_lock_wait+0x56/0xb0

Suggested-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Fixes: ea127f9754 ("[PATCH] s390 (7/7): zfcp host adapter.") (tglx/history.git)
Cc: <stable@vger.kernel.org> #2.6.32+
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

zfcp: close window with unblocked rport during rport gone

On a successful end of reopen port forced,
zfcp_erp_strategy_followup_success() re-uses the port erp_action
and the subsequent zfcp_erp_action_cleanup() now
sees ZFCP_ERP_SUCCEEDED with
erp_action->action==ZFCP_ERP_ACTION_REOPEN_PORT
instead of ZFCP_ERP_ACTION_REOPEN_PORT_FORCED
but must not perform zfcp_scsi_schedule_rport_register().

We can detect this because the fresh port reopen erp_action
is in its very first step ZFCP_ERP_STEP_UNINITIALIZED.

Otherwise this opens a time window with unblocked rport
(until the followup port reopen recovery would block it again).
If a scsi_cmnd timeout occurs during this time window
fc_timed_out() cannot work as desired and such command
would indeed time out and trigger scsi_eh. This prevents
a clean and timely path failover.
This should not happen if the path issue can be recovered
on FC transport layer such as path issues involving RSCNs.

Also, unnecessary and repeated DID_IMM_RETRY for pending and
undesired new requests occur because internally zfcp still
has its zfcp_port blocked.

As follow-on errors with scsi_eh, it can cause,
in the worst case, permanently lost paths due to one of:
sd <scsidev>: [<scsidisk>] Medium access timeout failure. Offlining disk!
sd <scsidev>: Device offlined - not ready after error recovery

For fix validation and to aid future debugging with other recoveries
we now also trace (un)blocking of rports.

Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Fixes: 5767620c383a ("[SCSI] zfcp: Do not unblock rport from REOPEN_PORT_FORCED")
Fixes: a2fa0aede07c ("[SCSI] zfcp: Block FC transport rports early on errors")
Fixes: 5f852be9e11d ("[SCSI] zfcp: Fix deadlock between zfcp ERP and SCSI")
Fixes: 338151e06608 ("[SCSI] zfcp: make use of fc_remote_port_delete when target port is unavailable")
Fixes: 3859f6a248cb ("[PATCH] zfcp: add rports to enable scsi_add_device to work again")
Cc: <stable@vger.kernel.org> #2.6.32+
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: Do not set cmd_per_lun to 1 in the host template

'0' is now used as the default cmd_per_lun value,
so there's no need to explicitly set it to '1' in the
host template.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

scsi: drop reason argument from ->change_queue_depth

Drop the now unused reason argument from the ->change_queue_depth method.
Also add a return value to scsi_adjust_queue_depth, and rename it to
scsi_change_queue_depth now that it can be used as the default
->change_queue_depth implementation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>

scsi: avoid ->change_queue_depth indirection for queue full tracking

All drivers use the implementation for ramping the queue up and down, so
instead of overloading the change_queue_depth method call the
implementation diretly if the driver opts into it by setting the
track_queue_depth flag in the host template.

Note that a few drivers validated the new queue depth in their
change_queue_depth method, but as we never go over the queue depth
set during slave_configure or the sysfs file this isn't nessecary
and can safely be removed.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Venkatesh Srinivas <venkateshs@google.com>

scsi: don't set tagging state from scsi_adjust_queue_depth

Remove the tagged argument from scsi_adjust_queue_depth, and just let it
handle the queue depth. For most drivers those two are fairly separate,
given that most modern drivers don't care about the SCSI "tagged" status
of a command at all, and many old drivers allow queuing of multiple
untagged commands in the driver.

Instead we start out with the ->simple_tags flag set before calling
->slave_configure, which is how all drivers actually looking at
->simple_tags except for one worke anyway. The one other case looks
broken, but I've kept the behavior as-is for now.

Except for that we only change ->simple_tags from the ->change_queue_type,
and when rejecting a tag message in a single driver, so keeping this
churn out of scsi_adjust_queue_depth is a clear win.

Now that the usage of scsi_adjust_queue_depth is more obvious we can
also remove all the trivial instances in ->slave_alloc or ->slave_configure
that just set it to the cmd_per_lun default.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>

[SCSI] zfcp: block queue limits with data router

Commit 86a9668a8d29ea711613e1cb37efa68e7c4db564
"[SCSI] zfcp: support for hardware data router"
reduced the initial block queue limits in the scsi_host_template to the
absolute minimum and adjusted them later on. However, the adjustment was
too late for the BSG devices of Scsi_Host and fc_host.

Therefore, ioctl(..., SG_IO, ...) with request or response size > 4kB to a
BSG device of an fc_host or a Scsi_Host fails with EINVAL. As a result,
users of such ioctl such as HBA_SendCTPassThru() in libzfcphbaapi return
with error HBA_STATUS_ERROR.

Initialize the block queue limits in zfcp_scsi_host_template to the
greatest common denominator (GCD).

While we cannot exploit the slightly enlarged maximum request size with
data router, this should be neglectible. Doing so also avoids running into
trouble after live guest relocation (LGR) / migration from a data router
FCP device to an FCP device that does not support data router. In that
case, zfcp would figure out the new limits on adapter recovery, but the
fc_host and Scsi_Host (plus in fact all sdevs) still exist with the old and
now too large queue limits.

It should also OK, not to use half the size as in the DIX case, because
fc_host and Scsi_Host do not transport FCP requests including SCSI commands
using protection data.

Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Reviewed-by: Martin Peschke <mpeschke@linux.vnet.ibm.com>
Cc: <stable@vger.kernel.org> #3.2+
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

s390/comments: unify copyright messages and remove file names

Remove the file name from the comment at top of many files. In most
cases the file name was wrong anyway, so it's rather pointless.

Also unify the IBM copyright statement. We did have a lot of sightly
different statements and wanted to change them one after another
whenever a file gets touched. However that never happened. Instead
people start to take the old/"wrong" statements to use as a template
for new files.
So unify all of them in one go.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

[SCSI] zfcp: return early from slave_destroy if slave_alloc returned early

zfcp_scsi_slave_destroy erroneously always tried to finish its task
even if the corresponding previous zfcp_scsi_slave_alloc returned
early. This can lead to kernel page faults on accessing uninitialized
fields of struct zfcp_scsi_dev in zfcp_erp_lun_shutdown_wait. Take the
port field of the struct to determine if slave_alloc returned early.

This zfcp bug is exposed by 4e6c82b (in turn fixing f7c9c6b to be
compatible with 21208ae) which can call slave_destroy for a
corresponding previous slave_alloc that did not finish.

This patch is based on James Bottomley's fix suggestion in
http://www.spinics.net/lists/linux-scsi/msg55449.html.

Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Cc: <stable@kernel.org> #2.6.38+
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

s390: add missing module.h/export.h includes

Fix several compile errors on s390 caused by splitting module.h.

Some include additions [e.g. qdio_setup.c, zfcp_qdio.c] are in
anticipation of pending changes queued for s390 that increase
the modular use footprint.

[PG: added additional obvious changes since Heiko's original patch]

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

[SCSI] zfcp: support for hardware data router

FICON Express8S supports hardware data router, which requires an
adapted qdio request format.
This part 2/2 exploits the functionality in zfcp.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] zfcp: non-experimental support for DIF/DIX

DIF/DIX support for zfcp is no longer experimental,
and config option is no longer necessary.
Return error from queuecommand for unsupported data directions.

Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

atomic: use <linux/atomic.h>

This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>

Signed-off-by: Arun Sharma <asharma@fb.com>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[SCSI] zfcp: Add information to symbolic port name when running in NPIV mode

Query the FC symbolic port name for reporting in the fc_host sysfs and
enable the symbolic_name attribute in the fc_host sysfs. When running
in NPIV mode, extend the symbolic port name with the devno and the
hostname. This allows better identification of Linux systems for SAN
and storage administrators.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] zfcp: Move SCSI host and transport templates out of struct zfcp_data

The SCSI host and transport templates are the only members left in the
global zfcp_data struct. Move them out of zfcp_data and remove the
now unused zfcp_data struct. Also update the names of the register and
unregister functions to use the zfcp_scsi prefix.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] zfcp: Add allow_lun_scan module parameter

The zfcpdump tool requires a method to attach exactly one LUN. The
easiest way to achieve this is to add a new zfcp module parameter.
When allow_lun_scan is set to "false", zfcp only accepts LUNs that
have been configured through the unit_add sysfs interface.

Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] zfcp: Redesign of the debug tracing final cleanup.

This patch is the final cleanup of the redesign from the zfcp tracing.
Structures and elements which were used by multiple areas of the
former debug tracing are now changed to the new scheme.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] zfcp: Redesign of the debug tracing for SCSI records.

This patch is the continuation to redesign the zfcp tracing to a more
straight-forward and easy to extend scheme.

This patch deals with all trace records of the zfcp SCSI area.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] zfcp: Issue FCP command without holding SCSI host_lock

Interrupting the connection to the FCP channel while I/O requests are
being issued can lead to this deadlock. scsi_dispatch_cmd already
holds the host_lock while the recovery trigger tries to acquire the
host_lock again when iterating through the scsi_devices.

INFO: lockdep is turned off.
BUG: spinlock lockup on CPU#1, blast/9660, 0000000078f38878
CPU: 1 Not tainted 2.6.35.7SWEN2 #2
Process blast (pid: 9660, task: 0000000071f75940, ksp: 0000000074393ac0)
0000000074393640 00000000743935c0 0000000000000002 0000000000000000
0000000074393660 00000000743935d8 00000000743935d8 00000000005590c2
0000000000000000 0000000078f38878 0000000026ede800 0000000078f38878
000000000000000d 040000000000000c 0000000074393628 0000000000000000
0000000000000000 0000000000100b2a 00000000743935c0 0000000074393600
Call Trace:
([<0000000000100a32>] show_trace+0xee/0x144)
[<00000000003be202>] do_raw_spin_lock+0x112/0x178
[<000000000055d408>] _raw_spin_lock_irqsave+0x90/0xb0
[<00000000003f1514>] __scsi_iterate_devices+0x38/0xbc
[<00000000004849b0>] zfcp_erp_clear_adapter_status+0xd0/0x16c
[<000000000048587a>] zfcp_erp_adapter_reopen+0x3a/0xb4
[<0000000000489812>] zfcp_fsf_req_send+0x166/0x180
[<000000000048c8d6>] zfcp_fsf_fcp_cmnd+0x272/0x408
[<000000000048f864>] zfcp_scsi_queuecommand+0x11c/0x1e0
[<00000000003f1f2a>] scsi_dispatch_cmd+0x1d6/0x324
[<00000000003f9910>] scsi_request_fn+0x42c/0x56c
[<00000000003828ae>] __blk_run_queue+0x86/0x140
[<000000000037f742>] elv_insert+0x11a/0x208
[<000000000038104c>] blk_insert_cloned_request+0x84/0xe4
[<000003c0032b7c64>] dm_dispatch_request+0x6c/0x94 [dm_mod]
[<000003c0032b7d5c>] map_request+0xd0/0x100 [dm_mod]
[<000003c0032b9a78>] dm_request_fn+0xec/0x1bc [dm_mod]
[<0000000000382c0e>] generic_unplug_device+0x5a/0x6c
[<000003c0032b7f98>] dm_unplug_all+0x74/0x9c [dm_mod]
[<00000000001d1272>] sync_page+0x76/0x9c
[<00000000001d12ba>] sync_page_killable+0x22/0x60
[<000000000055a768>] __wait_on_bit_lock+0xc0/0x124
[<00000000001d1140>] __lock_page_killable+0x78/0x84
[<00000000001d351c>] generic_file_aio_read+0x5a4/0x7e8
[<0000000000228ec0>] do_sync_read+0xc8/0x12c
[<0000000000229edc>] vfs_read+0xac/0x1ac
[<000000000022a0d8>] SyS_read+0x58/0xa8
[<00000000001146de>] sysc_noemu+0x10/0x16
[<00000200000493c4>] 0x200000493c4
INFO: lockdep is turned off.

Call zfcp_fsf_fcp_cmnd without the host_lock and disable the
interrupts when acquiring the req_q_lock. According to the patch
description in "[PATCH] Eliminate error handler overload of the SCSI
serial number", the serial_number is not used, so simply drop the
queuecommand wrapper function and run zfcp_scsi_queuecommand without
holding the host_lock.

Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

SCSI host lock push-down

Move the mid-layer's ->queuecommand() invocation from being locked
with the host lock to being unlocked to facilitate speeding up the
critical path for drivers who don't need this lock taken anyway.

The patch below presents a simple SCSI host lock push-down as an
equivalent transformation. No locking or other behavior should change
with this patch. All existing bugs and locking orders are preserved.

Additionally, add one parameter to queuecommand,
struct Scsi_Host *
and remove one parameter from queuecommand,
void (*done)(struct scsi_cmnd *)

Scsi_Host* is a convenient pointer that most host drivers need anyway,
and 'done' is redundant to struct scsi_cmnd->scsi_done.

Minimal code disturbance was attempted with this change. Most drivers
needed only two one-line modifications for their host lock push-down.

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Acked-by: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[SCSI] zfcp: Replace status modifier functions.

Replace the zfcp_modify_<xxx>_status functions and its accompanying wrappers
with dedicated status modifier functions. This eases code readability and
maintenance.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] zfcp: Allow midlayer to scan for LUNs when running in NPIV mode

Enable the LUN scanning mechanism in the SCSI midlayer:
- Do not set the disable_target_scan bit in the FC transport class.
- Set max_lun to 0xFFFFFFFF to allow the midlayer scan to include
the two-level hierachical LUNs (like 0x40XX40XX00000000, but in SCSI
midlayer LUN format).
- Set max_id to a high value to allow triggering the SCSI device
rescan from sysfs.

When running in NPIV mode, zfcp accepts all LUNs in slave_attach. When
running in non-NPIV mode, the list of zfcp_unit structs determines
which SCSI devices are allowed on the current system.

Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] zfcp: Use SCSI device data zfcp_scsi_dev instead of zfcp_unit

This is the large change to switch from using the data in
zfcp_unit to zfcp_scsi_dev. Keeping everything working requires doing
the switch in one piece. To ensure that no code keeps using the data
in zfcp_unit, this patch also removes the data from zfcp_unit that is
now being replaced with zfcp_scsi_dev.

For zfcp, the scsi_device together with zfcp_scsi_dev exist from the
call of slave_alloc to the call of slave_destroy. The data in
zfcp_scsi_dev is initialized in zfcp_scsi_slave_alloc and the LUN is
opened; the final shutdown for the LUN is run from slave_destroy.

Where the scsi_device or zfcp_scsi_dev is needed, the pointer to the
scsi_device is passed as function argument and inside the function
converted to the pointer to zfcp_scsi_dev; this avoids back and forth
conversion betweeen scsi_device and zfcp_scsi_dev.

While changing the function arguments from zfcp_unit to scsi_device,
the functions names are renamed form "unit" to "lun". This is to have
a seperation between zfcp_scsi_dev/LUN and the zfcp_unit; only code
referring to the remaining configuration information in zfcp_unit
struct uses "unit".

Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] zfcp: Move code for managing zfcp_unit devices to new file

Move the code for managing zfcp_unit devices to the new file
zfcp_unit.c. This is in preparation for the change that zfcp_unit will
only track the LUNs configured via unit_add, other data will be moved
from zfcp_unit to the new struct zfcp_scsi_dev.

Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

zfcp: Report scatter gather limit for DIX protection information

When sending DIX integrity segments with an I/O request, the
restriction for the maximum number of segments is still the same for
the zfcp hardware. Report the new sg_prot_tablesize for the SCSI host,
so that the number of integrity segments plus the number of data
segments is not larger than the hardware limit. This results in using
half of the hardware segments for integrity data and the other half
for regular data.

Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Jens Axboe <axboe@carl.home.kernel.dk>

[SCSI] zfcp: Introduce experimental support for DIF/DIX

Introduce support for DIF/DIX in zfcp: Report the capabilities for the
Scsi_host, map the protection data when issuing I/O requests and
handle the new error codes. Also add the fsf data_direction field to
the hba trace, it is useful information for debugging in that area.
This is an EXPERIMENTAL feature for now.

Signed-off-by: Felix Beck <felix.beck@de.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] zfcp: Cleanup function parameters for sbal value.

A lot of functions require the amount of SBALs as one of their
parameter which is most times invariable. Therefore remove this
parameter and set the SBAL value explicitly if a non standard value is
required. In addition the warning message "oversized data" is
replaced with a BUG_ON() statement assuring the limits defined and
requested by zfcp.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] zfcp: Remove SCSI device when removing unit

Configuring a LUN in zfcp, also creates a SCSI device. For
consistency, it makes sense to remove the SCSI device when the LUN is
deconfigured. Replace the flush_work with the call to
scsi_remove_device: scsi_remove_device also takes the scan_mutex that
synchronizes itself with any long running device discovery.

Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] zfcp: Use forced_reopen in terminate_rport_io callback

When running in non-NPIV mode, the port_reopen in terminate_rport_io
might succeed even though the remote port is not available. If the
same port connection is held open from another operating system, the
reopen is only a virtual operation and might not hit the SAN. Fix this
by changing the call to forced_reopen that forces a logout/login
operation in the SAN.

Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] zfcp: Register SCSI devices after successful fc_remote_port_add

When the successful return of an adisc is the final step to set the
port online, the registration of SCSI devices might be omitted. SCSI
devices that have been removed before (due to a short dev_loss_tmo
setting) might not be attached again.

The problem is that the registration of SCSI devices is done only
after erp has finished. The correct place would be after the call to
fc_remote_port_add to mimick the scan in the FC transport class.

Change the registration of SCSI devices to be triggered after the
fc_remote_port_add call. For the initial inquiry command to succeed,
the unit must also be open. If the unit reopen is still pending, the
inquiry command to the LUN will be deferred with DID_IMM_RETRY, so
there is no harm from this approach.

Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] zfcp: Move sbale handling to zfcp_qdio files

Move the code accessing the qdio sbales and zfcp_qdio_req struct to
the zfcp_qdio files and provide helper functions for accessing the
qdio related parts.

Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] zfcp: Report scatter-gather limits to SCSI and block layer

Instead of dealing with large segments in the scatter-gather lists in
zfcp_qdio.c, report the limits to the upper layers. With these limits
in place, the code for mapping large data blocks to multiple sbales
can be removed.

Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] zfcp: Pass return code from fc_block_scsi_eh to scsi eh

The return code FAST_IO_FAIL from fc_block_scsi_eh indicates that the
pending I/O requests have been terminated as a result of the
fast_io_fail_tmo. Pass this return code back to the scsi eh to stop
the scsi eh in this case.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

[SCSI] zfcp: Move scsi result tracing decision to zfcp_dbf.h

Move the decision which trace tag and trace level to use for the scsi
result trace to zfcp_dbf.h. zfcp_dbf_scsi_result is already an inline
function, so move the trace code there, simplifying the response
handling in zfcp_fsf.c.

Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] zfcp: Rename sysfs_device attribute to dev in zfcp_unit and zfcp_port

Kernel code uses dev as short name for the struct device. Rename the
sysfs_device in zfcp_unit and zfcp_port to match this convention.

Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] zfcp: Fix warnings from smatch

The smatch tool from http://repo.or.cz/w/smatch.git warns about this:

drivers/s390/scsi/zfcp_scsi.c +64 zfcp_scsi_command_fail(5) warn: variable dereferenced before check 'scpnt->device'
drivers/s390/scsi/zfcp_scsi.c +64 zfcp_scsi_command_fail(5) warn: variable dereferenced before check 'scpnt->device->host'
drivers/s390/scsi/zfcp_scsi.c +93 zfcp_scsi_queuecommand(23) warn: variable dereferenced before check 'unit'

Fix the first two warnings by removing the checks for scpnt->device
and -> host: As long as the SCSI command exists, there is also a
scsi_device and a Scsi_Host.

Fix the last warning by removing the BUG_ON checks in
zfcp_scsi_queuecommand, they are leftovers from previous paranoia
about wrong pointers between data structures.

Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] zfcp: Move FSF request tracking code to new file

Move the code for tracking FSF requests to new file to have this code
in one place. The functions for adding and removing requests on the
I/O path are already inline. The alloc and free functions are only
called once, so it does not hurt to inline them and add them to the
same file.

Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] zfcp: Introduce bsg_timeout callback.

Introduce a zfcp callback for timeouts triggered from FC BSG. With
zfcp, the underlying hardware cannot abort CT or ELS requests, so
there is nothing to do when the block layer timeout expires. To avoid
interference with the block layer timeout, simply indicate that the
block layer timer should be reset. The timer running in the hardware
for the pending CT or ELS request will return the request when it
expires.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] zfcp: Remove flag ZFCP_STATUS_FSFREQ_TMFUNCNOTSUPP

The flag ZFCP_STATUS_FSFREQ_TMFUNCNOTSUPP is never set and hence can
be removed. This is a leftover from the time when zfcp had to decide
whether the target supports a "logical unit reset" or not. Nowadays,
the SCSI midlayer calls the eh_device_reset_handler or the
eh_target_reset_handler and zfcp simply maps this to a "logical unit
reset" or a "target reset".

Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] zfcp: Activate fc4s attributes for zfcp in FC transport class

Enable the display of supported and active fc4s for zfcp in the FC
transport class. zfcp only supports FCP, so simply hard-code this
information. The zfcp hbaapi already has this information hardcoded,
but this would allow to switch from the coding in the zfcp hbaapi to
the common FC transport attributes in the future.

Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] zfcp: Block scsi_eh thread for rport state BLOCKED

In case the SCSI error recovery starts because of a SCSI command
timeout, but then something else triggers the rport to be deleted, the
SCSI error recovery will run to the end and set the SCSI device
offline. To prevent this, call the FC transport function
fc_block_scsi_eh which waits until the rport leaves the BLOCKED state.
This guarantees that communication is possible if the rport is ONLINE,
or the SCSI devices will be removed if the rport state switches to
NOT_PRESENT.

Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] zfcp: Simplify handling of ct and els requests

Remove some redundancies in FC related code and trace:
- drop redundant data from SAN trace (local s_id that only changes
during link down, ls_code that is already part of payload, d_id in
ct response trace that is always the same as in ct request trace)
- use one common fsf struct to hold zfcp data for ct and els requests
- leverage common fsf struct for FC passthrough job data, allocate it
with dd_bsg_data for passthrough requests and unify common code for
ct and els passthrough request
- simplify callback handling in zfcp_fc

Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] zfcp: Update FCP protocol related code

Use common data structures for FCP CMND, FCP RSP and related
definitions and remove zfcp private definitions. Split the FCP CMND
setup and FCP RSP evaluation code in seperate functions. Use inline
functions to not negatively impact the I/O path.

Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] zfcp: Dont fail SCSI commands when transitioning to blocked fc_rport

If an error occurs that triggers the call to fc_remote_port_delete,
ideally this call would happen before any I/O is passed back to the
SCSI midlayer through scsi_done. The SCSI midlayer will retry the
commands and fc_remote_port_chkready will return the correct status
code. But with the delay between calling scsi_done in softirq context
and the call to fc_remote_port_delete from the workqueue, there is a
window where zfcp returns DID_ERROR. This leads to SCSI error recovery
which then leads to offline SCSI devices since all recovery actions
will fail with the rport now being blocked.

In this window, zfcp has to return DID_IMM_RETRY just as the FC
transport class would do in fc_remote_port_chkready for the blocked
fc_rport. As soon as the fc_rport is BLOCKED, fc_remote_port_chkready
will do the right thing.

Additionally, there are two more cases to catch in zfcp_scsi_queuecommand:
- After the port has been opened, the unit has to be opened. During
this period I/O has to be retried. This can also be handled with
DID_IMM_RETRY.
- If the access to the unit fails, but the port is good, then
this single unit cannot be accessed and I/O to this unit has to fail
without involving the FC transport class.

Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] zfcp: Replace local reference counting with common kref

Replace the local reference counting by already available mechanisms
offered by kref. Where possible existing device structures were used,
including the same functionality.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] zfcp: Replace global config_lock with local list locks

The global config_lock was used to protect the configuration organized
in independent lists. It is not necessary to have a lock on driver
level for this purpose. This patch replaces the global config_lock
with a set of local list locks.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] zfcp: Adapt change_queue_depth for queue full tracking

Adapt the change_queue_depth callback in zfcp for the new reason
parameter. Simply pass each call back to the SCSI midlayer, there are
no resource adjustments necessary for zfcp.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>

Removes check for (depth <= default_depth) in case of
SCSI_QDEPTH_RAMP_UP call back, not needed after added
max_queue_depth per sdev.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] modify change_queue_depth to take in reason why it is being called

This patch modifies scsi_host_template->change_queue_depth so that
it takes an argument indicating why it is being called. This will be
used so that if a LLD needs to do some extra processing when
handling queue fulls or later ramp ups, it can do so.

This is a simple port of the drivers setting a change_queue_depth
callback. In the patch I just have these LLDs adjust the queue depth
if the user was requesting it.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>

[Vasu.Dev: v2
Also converted pmcraid_change_queue_depth and then verified
all modules compile using "make allmodconfig" for any new build
warnings on X86_64.

Updated original description after combing two original
patches from Mike to make this patch git bisectable.]
Signed-off-by: Vasu Dev <vasu.dev@intel.com>
[jejb: fixed up 53c700]
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

trivial: remove unnecessary semicolons

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

[SCSI] zfcp: resolve false usage of dd_data in fc_rport

The fc_rport structure reserves a reference where a LLD can put
information required in a situation where the fc transport class is
triggering LLD callbacks. The zfcp driver was using this variable
directly which is discouraged. This patch solves this issue by making
this reference unnecessary. In addition the dev_loss_tmo callback is
removed, it is not required: zfcp does not access the fc_rport after
calling fc_remote_port_delete.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] zfcp: Update dbf calls

Change the dbf data and functions to use the zfcp_dbf prefix
throughout the code. Also change the calls to dbf to use zfcp_dbf
instead of zfcp_adapter.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] zfcp: Move qdio related data out of zfcp_adapter

The zfcp_adapter structure was growing over time to a size of almost
one memory page. To reduce the size of the data structure and to
seperate different layers, put all qdio related data in the new
zfcp_qdio data structure.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] zfcp: Move workqueue to adapter struct

Remove the global driver work queue and replace it with a workqueue
local to the adapter. The usage of this workqueue makes this the
correct place for the structure. In addition multiple adapters won't
block each other due to the serialization of the queued work.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] zfcp: Replace fsf_req wait_queue with completion

The combination wait_queue/wakeup in conjunction with the flag
ZFCP_STATUS_FSFREQ_COMPLETED to signal the completion of an fsfreq
was not race-safe and can be better solved by a completion.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] zfcp: Only collect SCSI debug data for matching trace levels

The default trace level is to only trace failed SCSI commands. Thus it
is not necessary to collect trace data for most SCSI commands since it
will be thrown away later. Restructure the SCSI trace infrastructure
to first check the trace level in a inline function and only do the
expensive data collection for matching trace levels.

Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] zfcp: invalid usage after free of port resources

In certain error scenarios ports, rports are getting attached,
validated and removed from the systems environment. Depending on the
layer this occurs asynchronously. This patch fixes the few races
which existed and ensures all references and cross references are
cleared at the time they're invalid. In addition fc transports
actions are only scheduled when required.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] zfcp: Fix tracing of request id for abort requests

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

[SCSI] zfcp: Add port only once to FC transport class

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

[SCSI] zfcp: Add FC pass-through support

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=2

Signed-off-by: Sven Schuetz <sven@linux.vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] zfcp: Make queue_depth adjustable

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

[SCSI] zfcp: Fix oops when port disappears

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: Martin Petermann <martin@linux.vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] zfcp: Fix abort handler for completions in progress

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: Martin Petermann <martin@linux.vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] zfcp: Dont block zfcp_wq with scan

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

[SCSI] zfcp: erp failed status bit will not be set

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: Martin Petermann <martin@linux.vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] zfcp: Block FC transport rports early on errors

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

[SCSI] zfcp: replace current ERP logging with a more convenient version

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

[SCSI] zfcp: Improve reliability of SCSI eh handlers in zfcp

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

[SCSI] zfcp: Remove UNIT_REGISTERED status flag

Use the device pointer in zfcp_unit for tracking if we have a
registered SCSI device. With this approach, the flag
ZFCP_STATUS_UNIT_REGISTERED is only redundant and can be removed.

Acked-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[S390] convert zfcp printks to pr_xxx macros.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

[SCSI] zfcp: prevent double decrement on host_busy while being busy

The zfcp_scsi_queuecommand was not acting according to the standard
when the respective unit was not available. In this case an -EBUSY was
returned, which is not valid in itself, and in addition scsi_done
was called. This combination is not allowed and was leading to a
double finish of the request and therefor double decrement of the
host_busy counter.

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

[SCSI] zfcp: Dont clear reference from SCSI device to unit

It is possible that a remote port has a problem, the SCSI device gets
deleted after the rport timeout and then the timeout for pending SCSI
commands trigger an abort. For this case, don't delete the reference
from the SCSI device to the zfcp unit, so that we can still have the
reference to issue an abort request.

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

[SCSI] zfcp: Simplify zfcp data structures

Reduce the size of zfcp data structures by removing unused and
redundant members. scsi_lun is only the mangled version of the
fcp_lun. So, remove the redundant field and use the fcp_lun instead.

Since the queue lock and the pci_batch indicator are only used in the
request queue, move them from the common queue struct to the adapter
struct.

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

[SCSI] zfcp: remove all typedefs and replace them with standards

Remove typedefs from zfcp, use already existing types instead.

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

[SCSI] zfcp: remove unused references, declarations and flags

- Remove unused references and declarations, including one instance
of the FC ls_adisc struct that has been defined twice.
- Also remove the flags COMMON_OPENING, COMMON_CLOSING,
ADAPTER_REGISTERED and XPORT_OK that are only set and cleared, but
not checked anywhere.
- Remove the zfcp specific atomic_test_mask makro. Simply use
atomic_read directly instead.
- Remove the zfcp internal sg helper functions and switch the places
where it is still used to call sg_virt directly.
- With the update of the QDIO code, the QDIO data structures no
longer use the volatile type qualifier. Now we can also remove the
volatile qualifiers from the zfcp code.

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

[SCSI] zfcp: Update message with input from review

Update the kernel messages in zfcp with input from the message review
and remove some messages that have been identified as redundant.

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

[SCSI] zfcp: zfcp_fsf cleanup.

Code cleanup for the zfcp_fsf.c file.

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

[SCSI] zfcp: consolidate sysfs things into one file.

zfcp was using three files to deal with sysfs representation
for adapters, ports and units. The consolidation into one file
prevents code-duplication and eases maintainability.

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

[SCSI] zfcp: Cleanup of code in zfcp_scsi.c

Cleanup code in zfcp_scsi.c, fix coding style issues and simplify the
code.

Signed-off-by: Martin Petermann <martin@linux.vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] zfcp: Move status accessors from zfcp to SCSI include file.

Move the accessor functions for the scsi_cmnd status from zfcp to the
SCSI include file. Change the interface to the functions to pass the
scsi_cmnd pointer instead of the status pointer.

Signed-off-by: Martin Petermann <martin@linux.vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] zfcp: Add port_state attribute to sysfs

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: Sven Schuetz <sven@linux.vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] zfcp: Message cleanup

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

[SCSI] zfcp: sysfs attributes for fabric and channel latencies

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

[SCSI] zfcp: Add some statistics provided by the FCP adapter to the sysfs

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

[SCSI] zfcp: Remove zfcp_erp_wait from slave destory handler to fix deadlock

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: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Martin Peschke <mp3@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] zfcp: fix 31 bit compile warnings

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: Martin Peschke <mp3@de.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] zfcp: Trace all triggers of error recovery activity

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: Martin Peschke <mp3@de.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] zfcp: Add traces for state changes.

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: Martin Peschke <mp3@de.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] zfcp: convert zfcp to use target reset and device reset handler

[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: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] zfcp: Hold queue lock when checking port/unit handle for FCP command

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: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Martin Peschke <mp3@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] zfcp: Fix deadlock when adding invalid LUN

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: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] zfcp: Use also port and adapter to identify unit in messages.

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

[SCSI] zfcp: Remove unnecessary eh_bus_reset_handler callback

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

[SCSI] zfcp: whitespace cleanup

Cleanup the whitepace from the entire zfcp driver to prevent
to have those changes in future feature or function patches.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] zfcp: cleanup, separation of ERP, non ERP-version for exchange_ functions

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: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] zfcp: Remove braces for only one statement

Remove braces for only one statement

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] zfcp: fix memory leak

fix memory leak.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] zfcp: IO stall after deleting and path checker changes after reenabling zfcp devices

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: Michael Loehr <mloehr2@linux.vnet.ibm.com>
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] zfcp: rework request ID management.

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: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] zfcp: Fix deadlock between zfcp ERP and SCSI

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: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[S390] Get rid of a lot of sparse warnings.

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

[SCSI] zfcp: initialize scsi_host_template.max_sectors with appropriate value

Define ZFCP_MAX_SECTORS and initialize scsi_host_template.max_sectors
with appropriate value.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[PATCH] completions: lockdep annotate on stack completions

All on stack DECLARE_COMPLETIONs should be replaced by:
DECLARE_COMPLETION_ONSTACK

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[SCSI] zfcp: fix: avoid removal of fsf reqs before qdio queues are down

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: Andreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] zfcp: introduce struct timer_list in struct zfcp_fsf_req

This instance will be used whenever a timer is needed for
a request by zfcp.

Signed-off-by: Andreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] zfcp: fix: use correct req_id in eh_abort_handler

zfcp's eh_abort_handler used the wrong request ID to
identify the request to be aborted. The bug was introduced
with commit fea9d6c7bcd8ff1d60ff74f27ba483b3820b18a3
for improved management of request IDs. The bug is
fixed with this patch.

Signed-off-by: Andreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] zfcp: create private slab caches to guarantee proper data alignment

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: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andreas Herrmann <aherrman@de.ibm.com>
Compile fix ups and
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] zfcp: minor erp bug fixes

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: Andreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[S390] Fix sparse warnings.

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

[SCSI] zfcp: make use of fc_remote_port_delete when target port is unavailable

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: Andreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] zfcp: evaluate plogi payload to set maxframe_size, supported_classes of rports

Signed-off-by: Ralph Wuerthner <rwuerthn@de.ibm.com>
Signed-off-by: Andreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] zfcp: (cleanup) removed superfluous macros, struct members, typedefs

Removed some macros, struct members and typedefs which were
unused or not necessary.

Signed-off-by: Andreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] zfcp: (cleanup) kmalloc/kzalloc replacement

Replace kmalloc/memset by kzalloc or kcalloc.

Signed-off-by: Andreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] zfcp: (cleanup) remove useless comments

Removed some useless comments.

Signed-off-by: Andreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] zfcp: (cleanup) shortened copyright and author information

Copyright update, shortened file headers, shortened author information.

Signed-off-by: Andreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] zfcp: fix device registration issues

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: Andreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] zfcp: correctly set this_id for hosts

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: Andreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] zfcp: fix logging during device reset

Avoid access to old fsf_requests if device reset is logged.

Signed-off-by: Maxim Shchetynin <maxim@de.ibm.com>
Signed-off-by: Andreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[PATCH] s390: Remove CVS generated information

- 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: Andreas Herrmann <aherrman@de.ibm.com>
Acked-by: Frank Pavlic <pavlic@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[SCSI] zfcp: transport class adaptations II

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: Andreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] zfcp: transport class adaptations

Added host stats, removed superfluous get_starget_ functions,
removed some attributes from zfcp specific sysfs tree (e.g.
scsi_host_no, scsi_lun, wwnn and d_id).
Host stats are given for the physical adapter port not for the
virtual adapter. Reset stats is implemented in the device driver.

Signed-off-by: Andreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] zfcp: fix return code of zfcp_scsi_slave_alloc

Change return code in slave_alloc to avoid irritating error message from
scsi_alloc_sdev() when scsi stack tries target scan.

Signed-off-by: Andreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] zfcp: add additional fc_host attributes

this patch adds some fc host attributes and removes its equivalents
from the zfcp_adapter structure and zfcp specific sysfs subtree.

Furthermore it removes superfluous calls to fc_remort_port_delete when
an adapter is set offline because rports will be removed by
fc_remove_host anyway.

Signed-off-by: Andreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] zfcp: enhancement of zfcp debug features

Debug features (DBFs) els_dbf, cmd_dbf and abt_dbf were removed and
san_dbf, hba_dbf and scsi_dbf were introduced. The erp_dbf did not
change.
The new traces improve debugging of problems with zfcp, scsi-stack,
multipath and hardware in the SAN. san_dbf traces things like ELS and
CT commands, hba_dbf saves HBA specific information of requests, and
scsi_dbf saves FCP and SCSI specific information of requests. Common
to all new DBFs is that they provide a so called structured view. This
significantly improves readability of the traces.

Signed-off-by: Andreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] zfcp: shorten eh_bus_reset and eh_host_reset handlers

Signed-off-by: Andreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] zfcp: remove function zfcp_fsf_req_wait_and_cleanup

Signed-off-by: Andreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] zfcp: remove union zfcp_req_data, use unit refcount for FCP commands

o union zfcp_req_data removed
o increment unit refcount when processing FCP commands
(This fixes a theoretical race: When all scsi commands of a unit
are aborted and the scsi_device is removed then the unit could be
removed before all fsf_requests of that unit are completely processed.)

Signed-off-by: Andreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[PATCH] zfcp: add rports to enable scsi_add_device to work again

This patch fixes a severe problem with 2.6.13-rc7.

Due to recent SCSI changes it is not possible to add any LUNs to the zfcp
device driver anymore. With registration of remote ports this is fixed.

Signed-off-by: Andreas Herrmann <aherrman@de.ibm.com>
Acked-by: James Bottomley <jejb@steeleye.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] Driver Core: drivers/s390/net/qeth_sys.c - drivers/usb/gadget/pxa2xx_udc.c: update device attribute callbacks

Signed-off-by: Yani Ioannou <yani.ioannou@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[SCSI] allow sleeping in ->eh_host_reset_handler()

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] allow sleeping in ->eh_bus_reset_handler()

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] allow sleeping in ->eh_device_reset_handler()

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] allow sleeping in ->eh_abort_handler()

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] zfcp: fix bug during adapter shutdown

Fixes a race between zfcp_fsf_req_dismiss_all and
zfcp_qdio_reqid_check. During adapter shutdown it occurred that a
request was cleaned up twice. First during its normal
completion. Second when dismiss_all was called. The fix is to
serialize access to fsf request list between zfcp_fsf_req_dismiss_all
and zfcp_qdio_reqid_check and delete a fsf request from the list if
its completion is triggered. (Additionally a rwlock was replaced by a
spinlock and fsf_req_cleanup was eliminated.)

Signed-off-by: Andreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!