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Steffen Maier c820657917 scsi: zfcp: reduce flood of fcrscn1 trace records on multi-element RSCN
If an incoming ELS of type RSCN contains more than one element, zfcp
suboptimally causes repeated erp trigger NOP trace records for each
previously failed port. These could be ports that went away.  It loops over
each RSCN element, and for each of those in an inner loop over all
zfcp_ports.

The trigger to recover failed ports should be just the reception of some
RSCN, no matter how many elements it has. So we can loop over failed ports
separately, and only then loop over each RSCN element to handle the
non-failed ports.

The call chain was:

  zfcp_fc_incoming_rscn
    for (i = 1; i < no_entries; i++)
      _zfcp_fc_incoming_rscn
        list_for_each_entry(port, &adapter->port_list, list)
          if (masked port->d_id match) zfcp_fc_test_link
          if (!port->d_id) zfcp_erp_port_reopen "fcrscn1"   <===

In order the reduce the "flooding" of the REC trace area in such cases, we
factor out handling the failed ports to be outside of the entries loop:

  zfcp_fc_incoming_rscn
    if (no_entries > 1)                                     <===
      list_for_each_entry(port, &adapter->port_list, list)  <===
        if (!port->d_id) zfcp_erp_port_reopen "fcrscn1"     <===
    for (i = 1; i < no_entries; i++)
      _zfcp_fc_incoming_rscn
        list_for_each_entry(port, &adapter->port_list, list)
          if (masked port->d_id match) zfcp_fc_test_link

Abbreviated example trace records before this code change:

Tag            : fcrscn1
WWPN           : 0x500507630310d327
ERP want       : 0x02
ERP need       : 0x02

Tag            : fcrscn1
WWPN           : 0x500507630310d327
ERP want       : 0x02
ERP need       : 0x00                 NOP => superfluous trace record

The last trace entry repeats if there are more than 2 RSCN elements.

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2019-03-27 21:26:12 -04:00
Steffen Maier 242ec14551 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: 1da177e4c3 ("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>
2019-03-27 21:26:12 -04:00
Steffen Maier fe67888fc0 scsi: zfcp: fix rport unblock if deleted SCSI devices on Scsi_Host
An already deleted SCSI device can exist on the Scsi_Host and remain there
because something still holds a reference.  A new SCSI device with the same
H:C:T:L and FCP device, target port WWPN, and FCP LUN can be created.  When
we try to unblock an rport, we still find the deleted SCSI device and
return early because the zfcp_scsi_dev of that SCSI device is not
ZFCP_STATUS_COMMON_UNBLOCKED. Hence we miss to unblock the rport, even if
the new proper SCSI device would be in good state.

Therefore, skip deleted SCSI devices when iterating the sdevs of the shost.
[cf. __scsi_device_lookup{_by_target}() or scsi_device_get()]

The following abbreviated trace sequence can indicate such problem:

Area           : REC
Tag            : ersfs_3
LUN            : 0x4045400300000000
WWPN           : 0x50050763031bd327
LUN status     : 0x40000000     not ZFCP_STATUS_COMMON_UNBLOCKED
Ready count    : n		not incremented yet
Running count  : 0x00000000
ERP want       : 0x01
ERP need       : 0xc1		ZFCP_ERP_ACTION_NONE

Area           : REC
Tag            : ersfs_3
LUN            : 0x4045400300000000
WWPN           : 0x50050763031bd327
LUN status     : 0x41000000
Ready count    : n+1
Running count  : 0x00000000
ERP want       : 0x01
ERP need       : 0x01

...

Area           : REC
Level          : 4		only with increased trace level
Tag            : ertru_l
LUN            : 0x4045400300000000
WWPN           : 0x50050763031bd327
LUN status     : 0x40000000
Request ID     : 0x0000000000000000
ERP status     : 0x01800000
ERP step       : 0x1000
ERP action     : 0x01
ERP count      : 0x00

NOT followed by a trace record with tag "scpaddy"
for WWPN 0x50050763031bd327.

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Fixes: 6f2ce1c6af ("scsi: zfcp: fix rport unblock race with LUN recovery")
Cc: <stable@vger.kernel.org> #2.6.32+
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>
2019-03-27 21:26:12 -04:00
Linus Torvalds 3591b19511 s390 updates for the 5.1 merge window
- A copy of Arnds compat wrapper generation series
 
  - Pass information about the KVM guest to the host in form the control
    program code and the control program version code
 
  - Map IOV resources to support PCI physical functions on s390
 
  - Add vector load and store alignment hints to improve performance
 
  - Use the "jdd" constraint with gcc 9 to make jump labels working again
 
  - Remove amode workaround for old z/VM releases from the DCSS code
 
  - Add support for in-kernel performance measurements using the
    CPU measurement counter facility
 
  - Introduce a new PMU device cpum_cf_diag to capture counters and
    store thenn as event raw data.
 
  - Bug fixes and cleanups
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Merge tag 's390-5.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 updates from Martin Schwidefsky:

 - A copy of Arnds compat wrapper generation series

 - Pass information about the KVM guest to the host in form the control
   program code and the control program version code

 - Map IOV resources to support PCI physical functions on s390

 - Add vector load and store alignment hints to improve performance

 - Use the "jdd" constraint with gcc 9 to make jump labels working again

 - Remove amode workaround for old z/VM releases from the DCSS code

 - Add support for in-kernel performance measurements using the CPU
   measurement counter facility

 - Introduce a new PMU device cpum_cf_diag to capture counters and store
   thenn as event raw data.

 - Bug fixes and cleanups

* tag 's390-5.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (54 commits)
  Revert "s390/cpum_cf: Add kernel message exaplanations"
  s390/dasd: fix read device characteristic with CONFIG_VMAP_STACK=y
  s390/suspend: fix prefix register reset in swsusp_arch_resume
  s390: warn about clearing als implied facilities
  s390: allow overriding facilities via command line
  s390: clean up redundant facilities list setup
  s390/als: remove duplicated in-place implementation of stfle
  s390/cio: Use cpa range elsewhere within vfio-ccw
  s390/cio: Fix vfio-ccw handling of recursive TICs
  s390: vfio_ap: link the vfio_ap devices to the vfio_ap bus subsystem
  s390/cpum_cf: Handle EBUSY return code from CPU counter facility reservation
  s390/cpum_cf: Add kernel message exaplanations
  s390/cpum_cf_diag: Add support for s390 counter facility diagnostic trace
  s390/cpum_cf: add ctr_stcctm() function
  s390/cpum_cf: move common functions into a separate file
  s390/cpum_cf: introduce kernel_cpumcf_avail() function
  s390/cpu_mf: replace stcctm5() with the stcctm() function
  s390/cpu_mf: add store cpu counter multiple instruction support
  s390/cpum_cf: Add minimal in-kernel interface for counter measurements
  s390/cpum_cf: introduce kernel_cpumcf_alert() to obtain measurement alerts
  ...
2019-03-05 11:13:10 -08:00
Julian Wiedmann bdf117674e s390/qdio: make SBAL address array type-safe
There is no need to use void pointers, all drivers are in agreement
about the underlying data structure of the SBAL arrays.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-02-07 11:57:07 +01:00
Steffen Maier b63195698d scsi: zfcp: fix sysfs block queue limit output for max_segment_size
Since v2.6.35 commit 683229845f ("[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 50c2e9107f ("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 a8cf59a669 ("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 a8cf59a669.

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>
2019-01-29 01:14:59 -05:00
Christoph Hellwig 2a3d4eb8e2 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>
2018-12-18 23:13:12 -05:00
Steffen Maier 7171455354 scsi: zfcp: improve kdoc for return of zfcp_status_read_refill()
Complements

v2.6.35 commit 64deb6efdc ("[SCSI] zfcp: Use status_read_buf_num
provided by FCP channel") which replaced the hardcoded 16 with a
variable value

Also complements already existing fixups for above commit

v2.6.35 commit 8d88cf3f3b ("[SCSI] zfcp: Update status read mempool")
v3.10   commit 9edf7d75ee ("[SCSI] zfcp: status read buffers on first adapter open with link down")

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-12-07 22:04:25 -05:00
Steffen Maier 60a161b7e5 scsi: zfcp: fix posting too many status read buffers leading to adapter shutdown
Suppose adapter (open) recovery is between opened QDIO queues and before
(the end of) initial posting of status read buffers (SRBs). This time
window can be seconds long due to FSF_PROT_HOST_CONNECTION_INITIALIZING
causing by design looping with exponential increase sleeps in the function
performing exchange config data during recovery
[zfcp_erp_adapter_strat_fsf_xconf()]. Recovery triggered by local link up.

Suppose an event occurs for which the FCP channel would send an unsolicited
notification to zfcp by means of a previously posted SRB.  We saw it with
local cable pull (link down) in multi-initiator zoning with multiple
NPIV-enabled subchannels of the same shared FCP channel.

As soon as zfcp_erp_adapter_strategy_open_fsf() starts posting the initial
status read buffers from within the adapter's ERP thread, the channel does
send an unsolicited notification.

Since v2.6.27 commit d26ab06ede ("[SCSI] zfcp: receiving an unsolicted
status can lead to I/O stall"), zfcp_fsf_status_read_handler() schedules
adapter->stat_work to re-fill the just consumed SRB from a work item.

Now the ERP thread and the work item post SRBs in parallel.  Both contexts
call the helper function zfcp_status_read_refill().  The tracking of
missing (to be posted / re-filled) SRBs is not thread-safe due to separate
atomic_read() and atomic_dec(), in order to depend on posting
success. Hence, both contexts can see
atomic_read(&adapter->stat_miss) == 1. One of the two contexts posts
one too many SRB. Zfcp gets QDIO_ERROR_SLSB_STATE on the output queue
(trace tag "qdireq1") leading to zfcp_erp_adapter_shutdown() in
zfcp_qdio_handler_error().

An obvious and seemingly clean fix would be to schedule stat_work from the
ERP thread and wait for it to finish. This would serialize all SRB
re-fills. However, we already have another work item wait on the ERP
thread: adapter->scan_work runs zfcp_fc_scan_ports() which calls
zfcp_fc_eval_gpn_ft(). The latter calls zfcp_erp_wait() to wait for all the
open port recoveries during zfcp auto port scan, but in fact it waits for
any pending recovery including an adapter recovery. This approach leads to
a deadlock.  [see also v3.19 commit 18f87a67e6 ("zfcp: auto port scan
resiliency"); v2.6.37 commit d3e1088d68
("[SCSI] zfcp: No ERP escalation on gpn_ft eval");
v2.6.28 commit fca55b6fb5
("[SCSI] zfcp: fix deadlock between wq triggered port scan and ERP")
fixing v2.6.27 commit c57a39a45a
("[SCSI] zfcp: wait until adapter is finished with ERP during auto-port");
v2.6.27 commit cc8c282963
("[SCSI] zfcp: Automatically attach remote ports")]

Instead make the accounting of missing SRBs atomic for parallel execution
in both the ERP thread and adapter->stat_work.

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Fixes: d26ab06ede ("[SCSI] zfcp: receiving an unsolicted status can lead to I/O stall")
Cc: <stable@vger.kernel.org> #2.6.27+
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-12-07 22:03:24 -05:00
Fedor Loshakov 636db60b8e 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>
2018-12-07 21:36:40 -05:00
Steffen Maier 399b6c8bc9 scsi: zfcp: drop old default switch case which might paper over missing case
This was introduced with v2.6.27 commit 287ac01acf ("[SCSI] zfcp: Cleanup
code in zfcp_erp.c") but would now suppress helpful -Wswitch compiler
warnings when building with W=1 such as the following forced example:

drivers/s390/scsi/zfcp_erp.c: In function 'zfcp_erp_setup_act':
drivers/s390/scsi/zfcp_erp.c:220:2: warning: enumeration value 'ZFCP_ERP_ACTION_REOPEN_PORT' not handled in switch [-Wswitch]
  switch (need) {
  ^~~~~~

But then again, only with W=1 we would notice unhandled enum cases.
Without the default cases and a missed unhandled enum case, the code might
perform unforeseen things we might not want...

As of today, we never run through the removed default case, so removing it
is no functional change.  In the future, we never should run through a
default case but introduce the necessary specific case(s) to handle new
functionality.

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>
2018-11-15 15:01:18 -05:00
Steffen Maier 0c902936e5 scsi: zfcp: drop default switch case which might paper over missing case
This was introduced with v4.18 commit 8c3d20aada ("scsi: zfcp: fix
missing REC trigger trace for all objects in ERP_FAILED") but would now
suppress helpful -Wswitch compiler warnings when building with W=1 such as
the following forced example:

drivers/s390/scsi/zfcp_erp.c: In function 'zfcp_erp_handle_failed':
drivers/s390/scsi/zfcp_erp.c:126:2: warning: enumeration value 'ZFCP_ERP_ACTION_REOPEN_PORT_FORCED' not handled in switch [-Wswitch]
  switch (want) {
  ^~~~~~

But then again, only with W=1 we would notice unhandled enum cases.
Without the default cases and a missed unhandled enum case, the code might
perform unforeseen things we might not want...

As of today, we never run through the removed default case, so removing it
is no functional change.  In the future, we never should run through a
default case but introduce the necessary specific case(s) to handle new
functionality.

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>
2018-11-15 15:01:18 -05:00
Steffen Maier 3505144e54 scsi: zfcp: silence -Wimplicit-fallthrough in zfcp_erp_lun_strategy()
For some reason the already existing substring "fall through" in the
comment is not sufficient for GCC to silence -Wimplicit-fallthrough.

  CC [M]  drivers/s390/scsi/zfcp_erp.o
drivers/s390/scsi/zfcp_erp.c: In function 'zfcp_erp_lun_strategy':
drivers/s390/scsi/zfcp_erp.c:1065:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
  if (atomic_read(&zfcp_sdev->status) & ZFCP_STATUS_COMMON_OPEN)
      ^
drivers/s390/scsi/zfcp_erp.c:1068:2: note: here
  case ZFCP_ERP_STEP_LUN_CLOSING:
  ^~~~

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>
2018-11-15 15:01:18 -05:00
Steffen Maier 623cd180c1 scsi: zfcp: silence remaining kdoc warnings in header files
Improve whatever the following simple invocation reported:
$ ./scripts/kernel-doc -none drivers/s390/scsi/*.h

While at it, improve some related kdoc,
including struct zfcp_fsf_ct_els in zfcp_fsf.h.

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>
2018-11-15 15:01:18 -05:00
Steffen Maier 8684d61481 scsi: zfcp: silence all W=1 build warnings for existing kdoc
While at it also improve some copy & paste kdoc mistakes.

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>
2018-11-15 15:01:18 -05:00
Steffen Maier e0effe8935 scsi: zfcp: properly format LUN (and WWPN) for LUN sharing violation kmsg
zfcp: <devbusid>: LUN 0x0 on port 0x5005076......... ...
zfcp: <devbusid>: LUN 0x1000000000000 on port 0x5005076......... ...

should be

zfcp: <devbusid>: LUN 0x0000000000000000 on port 0x5005076......... ...
zfcp: <devbusid>: LUN 0x0001000000000000 on port 0x5005076.........
                  is already in use by CSS., MIF Image ID .

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>
2018-11-15 15:01:18 -05:00
Steffen Maier d5fcdced31 scsi: zfcp: use enum zfcp_erp_act_result for argument/return of affected functions
With that instead of just "int" it becomes clear which functions return
this type and which ones also accept it as argument they just pass through
in some cases or modify in other cases.  v2.6.27 commit 287ac01acf
("[SCSI] zfcp: Cleanup code in zfcp_erp.c") introduced the enum which was
cpp defines previously.

Silence some false -Wswitch compiler warning cases with individual
NOP cases. When adding more enum values and building with W=1 we
would get compiler warnings about missed new cases.

Consistently use the variable name "result", so change "retval" in
zfcp_erp_strategy() to "result". This avoids confusion with other compile
unit variables "retval" having different semantics and type.

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>
2018-11-15 15:01:18 -05:00
Steffen Maier 0023beece0 scsi: zfcp: use enum zfcp_erp_steps for struct zfcp_erp_action.step
Use the already defined enum for this purpose to get at least some build
checking (even though an enum is type equivalent to an int in C).  v2.6.27
commit 287ac01acf ("[SCSI] zfcp: Cleanup code in zfcp_erp.c") introduced
the enum which was cpp defines previously.

Since struct zfcp_erp_action type is embedded into other structures living
in zfcp_def.h, we have to move enum zfcp_erp_act_type from its private
definition in zfcp_erp.c to the zfcp-global zfcp_def.h

Silence some false -Wswitch compiler warning cases with individual NOP
cases. When adding more enum values and building with W=1 we would get
compiler warnings about missed new cases.

Add missing break statements in some of the above switch cases.  No
functional change, but making it future-proof.  I think all of these should
have had a break statement ever since, even if these switch cases happened
to be the last ones in the switch statement body.

"Fall through" in the context of switch case usually means not to have a
break and fall through to the subsequent switch case. However, I think this
old comment meant that here we do not have an _early return_ in the switch
case but the code path continues after the switch case body.

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>
2018-11-15 15:01:18 -05:00
Steffen Maier df91eefd08 scsi: zfcp: the action field of zfcp_erp_action is actually the type
&zfcp_erp_action.action ==> &zfcp_erp_action.type

While at it, make use of the already defined enum for this purpose to get
at least some build checking (even though an enum is type equivalent to an
int in C). v2.6.27 commit 287ac01acf ("[SCSI] zfcp: Cleanup code in
zfcp_erp.c") introduced the enum which was cpp defines previously.

To prevent compiler warnings with the switch(act->type), we have to
separate the recently added eyecatchers from enum zfcp_erp_act_type.

Since struct zfcp_erp_action type is embedded into other structures living
in zfcp_def.h, we have to move enum zfcp_erp_act_type from its private
definition in zfcp_erp.c to the zfcp-global zfcp_def.h.

Silence one false -Wswitch compiler warning case: LUNs as the leaves in our
object tree do not have any follow-up success recovery.

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>
2018-11-15 15:01:18 -05:00
Steffen Maier 208d096154 scsi: zfcp: clarify function argument name for trace tag string
v2.6.30 commit 5ffd51a5e4 ("[SCSI] zfcp: replace current ERP logging with
a more convenient version") changed trace record distinguishing from a
numerical ID to a 7 character string called "trace tag". While starting to
use function arguments with different type and semantics, it did not change
the argument name accordingly.

v2.6.38 commit ae0904f60f ("[SCSI] zfcp: Redesign of the debug tracing
for recovery actions.") renamed variable names "id" into "tag" but only
within zfcp_dbf.*, not within zfcp_erp.c.

This was a bit confusing since the remainder of zfcp does use the term
"trace tag". Also "id" is quite generic and it's not obvious for what.
Just unify it consistently and use the "dbf" prefix to relate the arguments
to the code in zfcp_dbf.*.

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>
2018-11-15 15:01:18 -05:00
Steffen Maier 64eba38418 scsi: zfcp: ERP thread setup kdoc update
zfcp_erp_thread_setup() update complements v2.6.32 commit 347c6a965d
("[SCSI] zfcp: Use kthread API for zfcp erp thread").

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>
2018-11-15 15:01:18 -05:00
Steffen Maier 724e144387 scsi: zfcp: update kernel message for invalid FCP_CMND length, it's not the CDB
The CDB is just a part inside of FCP_CMND, see zfcp_fc_scsi_to_fcp().
While at it, fix the device driver reaction: adapter not LUN shutdown.

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>
2018-11-15 15:01:17 -05:00
Steffen Maier 9704154fa0 scsi: zfcp: drop duplicate seq_no from zfcp_fsf_req which is also in QTCB header
There is no point for double bookkeeping especially just for tracing.  The
trace can take it from the QTCB which always exists for non-SRB responses
traced with zfcp_dbf_hba_fsf_res().

As a side effect, this removes an alignment hole and reduces the size of
struct zfcp_fsf_req, and thus of each pending request, by 8 bytes.

Before:
$ pahole -C zfcp_fsf_req drivers/s390/scsi/zfcp.ko
...
	struct fsf_qtcb *          qtcb;                 /*   144     8 */
	u32                        seq_no;               /*   152     4 */
	/* XXX 4 bytes hole, try to pack */
	void *                     data;                 /*   160     8 */
...
	/* size: 296, cachelines: 2, members: 14 */
	/* sum members: 288, holes: 2, sum holes: 8 */
	/* last cacheline: 40 bytes */
After:
$ pahole -C zfcp_fsf_req drivers/s390/scsi/zfcp.ko
...
	struct fsf_qtcb *          qtcb;                 /*   144     8 */
	void *                     data;                 /*   152     8 */
...
	/* size: 288, cachelines: 2, members: 13 */
        /* sum members: 284, holes: 1, sum holes: 4 */

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>
2018-11-15 15:01:17 -05:00
Steffen Maier f9eca02276 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>
2018-11-15 15:01:17 -05:00
Steffen Maier 2c53d8a0cc scsi: zfcp: drop unnecessary forward prototype for struct zfcp_fsf_req
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>
2018-11-15 15:01:17 -05:00
Steffen Maier 21cb0bcc73 scsi: zfcp: group sort internal structure definitions for proximity
Have structures just before the structures that use them (without
disrupting sequences of using structures such as zfcp_unit and
zfcp_scsi_dev):

 - zfcp_adapter_mempool embedded in zfcp_adapter,

 - zfcp_latenc... embedded in zfcp_scsi_dev.

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>
2018-11-15 15:01:17 -05:00
Steffen Maier eb67f93ffa scsi: zfcp: namespace prefix for internal latency data structures
In contrast to struct fsf_qual_latency_info, the ones here are not FSF but
software defined zfcp-internal.

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>
2018-11-15 15:01:17 -05:00
Steffen Maier e0c1da39d7 scsi: zfcp: update width in comment for ZFCP_COMMON_FLAGS mask
v2.6.10 history commit 4062e12b2ba2 ("[PATCH] s390: zfcp act enhancements")
extended this mask by one nibble with the introduction of
ZFCP_STATUS_COMMON_ACCESS_DENIED == 0x00800000 for ACT (access control
table).

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>
2018-11-15 15:01:17 -05:00
Steffen Maier a0e86d9555 scsi: zfcp: move scsi_eh & non-ERP timeout defines owned by and local to zfcp_fsf.c
Also clarify namespace prefix for the timeout used for FSF requests on
behalf of SCSI error recovery: It is zfcp_fsf_ not zfcp_scsi_.

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>
2018-11-15 15:01:17 -05:00
Steffen Maier c24635acce scsi: zfcp: drop unnecessary forward prototype for struct zfcp_reqlist
While struct zfcp_adapter contains a pointer to zfcp_reqlist, the pointer
field does not need to know the structure or even a prototype.

The prototype was introduced with v2.6.34 commit b6bd2fb92a ("[SCSI]
zfcp: Move FSF request tracking code to new file").

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>
2018-11-15 15:01:17 -05:00
Steffen Maier 58f3ead547 scsi: zfcp: move SG table helper from aux to fc and make them static
Since commit 663e0890e3 ("[SCSI] zfcp: remove access control tables
interface") these helper functions are only used for auto port scan in
zfcp_fc.c. Also change them to the corresponding namespace prefix.

This is a small cleanup for the miscellaneous catchall compile unit
zfcp_aux.c.

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>
2018-11-15 15:01:17 -05:00
zhong jiang 6be552276e scsi: zfcp: remove unnecessary null pointer check before mempool_destroy
mempool_destroy has taken null pointer check into account. so remove the
redundant check.

Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Acked-by: Benjamin Block <bblock@linux.ibm.com>
[maier@linux.ibm.com: depends on v4.3 4e3ca3e033 ("mm/mempool: allow NULL `pool' pointer in mempool_destroy()")]
Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-11-15 15:01:17 -05:00
Vasily Gorbik c6756b7d0c s390/dasd,zfcp: fix gcc 8 stringop-truncation warnings
ccw "busid" should always be NUL-terminated, as evident from e.g.
get_ccwdev_by_busid doing "return (strcmp(bus_id, dev_name(dev)) == 0)".

Replace all strncpy initializing busid with strlcpy. This fixes the
following gcc 8 warnings:

drivers/s390/scsi/zfcp_aux.c:104:2: warning: 'strncpy' specified bound 20
equals destination size [-Wstringop-truncation]
  strncpy(busid, token, ZFCP_BUS_ID_SIZE);

drivers/s390/block/dasd_eer.c:316:2: warning: 'strncpy' specified bound 10
equals destination size [-Wstringop-truncation]
  strncpy(header.busid, dev_name(&device->cdev->dev), DASD_EER_BUSID_SIZE);

drivers/s390/block/dasd_eer.c:359:2: warning: 'strncpy' specified bound 10
equals destination size [-Wstringop-truncation]
  strncpy(header.busid, dev_name(&device->cdev->dev), DASD_EER_BUSID_SIZE);

drivers/s390/block/dasd_devmap.c:429:3: warning: 'strncpy' specified bound
20 equals destination size [-Wstringop-truncation]
   strncpy(new->bus_id, bus_id, DASD_BUS_ID_SIZE);

Acked-by: Stefan Haberland <sth@linux.ibm.com>
Acked-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-07-02 11:24:52 +02:00
Linus Torvalds 5f85942c2e SCSI misc on 20180610
This is mostly updates to the usual drivers: ufs, qedf, mpt3sas, lpfc,
 xfcp, hisi_sas, cxlflash, qla2xxx.  In the absence of Nic, we're also
 taking target updates which are mostly minor except for the tcmu
 refactor. The only real core change to worry about is the removal of
 high page bouncing (in sas, storvsc and iscsi).  This has been well
 tested and no problems have shown up so far.
 
 Signed-off-by: James E.J. Bottomley <jejb@linux.vnet.ibm.com>
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Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

Pull SCSI updates from James Bottomley:
 "This is mostly updates to the usual drivers: ufs, qedf, mpt3sas, lpfc,
  xfcp, hisi_sas, cxlflash, qla2xxx.

  In the absence of Nic, we're also taking target updates which are
  mostly minor except for the tcmu refactor.

  The only real core change to worry about is the removal of high page
  bouncing (in sas, storvsc and iscsi). This has been well tested and no
  problems have shown up so far"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (268 commits)
  scsi: lpfc: update driver version to 12.0.0.4
  scsi: lpfc: Fix port initialization failure.
  scsi: lpfc: Fix 16gb hbas failing cq create.
  scsi: lpfc: Fix crash in blk_mq layer when executing modprobe -r lpfc
  scsi: lpfc: correct oversubscription of nvme io requests for an adapter
  scsi: lpfc: Fix MDS diagnostics failure (Rx < Tx)
  scsi: hisi_sas: Mark PHY as in reset for nexus reset
  scsi: hisi_sas: Fix return value when get_free_slot() failed
  scsi: hisi_sas: Terminate STP reject quickly for v2 hw
  scsi: hisi_sas: Add v2 hw force PHY function for internal ATA command
  scsi: hisi_sas: Include TMF elements in struct hisi_sas_slot
  scsi: hisi_sas: Try wait commands before before controller reset
  scsi: hisi_sas: Init disks after controller reset
  scsi: hisi_sas: Create a scsi_host_template per HW module
  scsi: hisi_sas: Reset disks when discovered
  scsi: hisi_sas: Add LED feature for v3 hw
  scsi: hisi_sas: Change common allocation mode of device id
  scsi: hisi_sas: change slot index allocation mode
  scsi: hisi_sas: Introduce hisi_sas_phy_set_linkrate()
  scsi: hisi_sas: fix a typo in hisi_sas_task_prep()
  ...
2018-06-10 13:01:12 -07:00
Jens Remus 16dad27988 scsi: zfcp: enhance comments on fc_link_speed and supported_speed
The comment on fsf_qtcb_bottom_port.supported_speed did read as if the field
can only assume one of two possible values (i.e. 0x1 for 1 GBit/s or 0x2 for
2 GBit/s). This is not true for two reasons: first it is a flag field and
can thus assume any combination and second there are meanwhile more speeds.

Clarify comment on fsf_qtcb_bottom_port.supported_speed and add a comment to
fsf_qtcb_bottom_config.fc_link_speed.

Signed-off-by: Jens Remus <jremus@linux.ibm.com>
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Fedor Loshakov <loshakov@linux.ibm.com>
Acked-by: Benjamin Block <bblock@linux.ibm.com>
Acked-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-05-18 11:28:17 -04:00
Jens Remus 6e2e490080 scsi: zfcp: add port speed capabilities
Add port speed capabilities as defined in FC-LS RPSC ELS that have a
counterpart FC_PORTSPEED_* defined in scsi/scsi_transport_fc.h.

Suggested-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Fedor Loshakov <loshakov@linux.ibm.com>
Acked-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Acked-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>
2018-05-18 11:28:16 -04:00
Jens Remus 9e156c54ac scsi: zfcp: assert that the ERP lock is held when tracing a recovery trigger
Otherwise iterating with list_for_each() over the adapter->erp_ready_head
and adapter->erp_running_head lists can lead to an infinite loop. See commit
"zfcp: fix infinite iteration on erp_ready_head list".

The run-time check is only performed for debug kernels which have the kernel
lock validator enabled. Following is an example of the warning that is
reported, if the ERP lock is not held when calling zfcp_dbf_rec_trig():

WARNING: CPU: 0 PID: 604 at drivers/s390/scsi/zfcp_dbf.c:288 zfcp_dbf_rec_trig+0x172/0x188
Modules linked in: ...
CPU: 0 PID: 604 Comm: kworker/u128:3 Not tainted 4.16.0-... #1
Hardware name: IBM 2964 N96 702 (z/VM 6.4.0)
Workqueue: zfcp_q_0.0.1906 zfcp_scsi_rport_work
Krnl PSW : 00000000330fdbf9 00000000367e9728 (zfcp_dbf_rec_trig+0x172/0x188)
           R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:3 PM:0 RI:0 EA:3
Krnl GPRS: 00000000c57a5d99 3288200000000000 0000000000000000 000000006cc82740
           00000000009d09d6 0000000000000000 00000000000000ff 0000000000000000
           0000000000000000 0000000000e1b5fe 000000006de01d38 0000000076130958
           000000006cc82548 000000006de01a98 00000000009d09d6 000000006a6d3c80
Krnl Code: 00000000009d0ad2: eb7ff0b80004        lmg        %r7,%r15,184(%r15)
           00000000009d0ad8: c0f4000d7dd0        brcl       15,b80678
          #00000000009d0ade: a7f40001            brc        15,9d0ae0
          >00000000009d0ae2: a7f4ff7d            brc        15,9d09dc
           00000000009d0ae6: e340f0f00004        lg         %r4,240(%r15)
           00000000009d0aec: eb7ff0b80004        lmg        %r7,%r15,184(%r15)
           00000000009d0af2: 07f4                bcr        15,%r4
           00000000009d0af4: 0707                bcr        0,%r7
Call Trace:
([<00000000009d09d6>] zfcp_dbf_rec_trig+0x66/0x188)
 [<00000000009dd740>] zfcp_scsi_rport_work+0x98/0x190
 [<0000000000169b34>] process_one_work+0x3d4/0x6f8
 [<000000000016a08a>] worker_thread+0x232/0x418
 [<000000000017219e>] kthread+0x166/0x178
 [<0000000000b815ea>] kernel_thread_starter+0x6/0xc
 [<0000000000b815e4>] kernel_thread_starter+0x0/0xc
2 locks held by kworker/u128:3/604:
 #0:  ((wq_completion)name){+.+.}, at: [<0000000082af1024>] process_one_work+0x1dc/0x6f8
 #1:  ((work_completion)(&port->rport_work)){+.+.}, at: [<0000000082af1024>] process_one_work+0x1dc/0x6f8
Last Breaking-Event-Address:
 [<00000000009d0ade>] zfcp_dbf_rec_trig+0x16e/0x188
---[ end trace b2f4020572e2c124 ]---

Suggested-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-05-18 11:28:16 -04:00
Steffen Maier 6919298c98 scsi: zfcp: cleanup indentation for posting FC events
I just happened to see the function header indentation of
zfcp_fc_enqueue_event() and I picked some more from checkpatch:

$ checkpatch.pl --strict -f drivers/s390/scsi/zfcp_fc.c
...
CHECK: Alignment should match open parenthesis
 #113: FILE: drivers/s390/scsi/zfcp_fc.c:113:
+		fc_host_post_event(adapter->scsi_host, fc_get_event_number(),
+				event->code, event->data);

CHECK: Blank lines aren't necessary before a close brace '}'
 #118: FILE: drivers/s390/scsi/zfcp_fc.c:118:
+
+}
...

The change complements v2.6.36 commit 2d1e547f75 ("[SCSI] zfcp: Post
events through FC transport class").

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>
2018-05-18 11:28:15 -04:00
Steffen Maier 35e9111a1e scsi: zfcp: support SCSI_ADAPTER_RESET via scsi_host sysfs attribute host_reset
Make use of feature introduced with v3.2 commit 2944369144 ("[SCSI] scsi:
Added support for adapter and firmware reset").  The common code interface
was introduced for commit 95d31262b3 ("[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>
2018-05-18 11:28:15 -04:00
Steffen Maier b24bf22d72 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 7a39ac3f25 ("[SCSI] make supported_mode default to
initiator.").  The feature flag was introduced with v2.6.24 commit
5dc2b89e12 ("[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>
2018-05-18 11:28:14 -04:00
Steffen Maier 2fdd45fd20 scsi: zfcp: remove unused return values of ERP trigger functions
Since v2.6.27 commit 553448f6c4 ("[SCSI] zfcp: Message cleanup"), none of
the callers has been interested any more.  Values were not returned
consistently in all ERP trigger functions.

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>
2018-05-18 11:28:14 -04:00
Steffen Maier 013af857d8 scsi: zfcp: zfcp_erp_action_exists() does only check for running
Simplify its signature to return boolean and rename it to
zfcp_erp_action_is_running() to indicate its actual unmodified semantics.
It has always been used like this since v2.6.0 history commit ea127f975424
("[PATCH] s390 (7/7): zfcp host adapter.").

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>
2018-05-18 11:28:13 -04:00
Steffen Maier cd4a186aaa scsi: zfcp: remove unused ERP enum values
All constant defines were introduced with v2.6.0 history commit ea127f975424
("[PATCH] s390 (7/7): zfcp host adapter.") and refactored into enums with
commit 287ac01acf ("[SCSI] zfcp: Cleanup code in zfcp_erp.c").

ZFCP_STATUS_ERP_DISMISSING and ZFCP_ERP_STEP_FSF_XCONFIG were never used.

v2.6.27 commit 287ac01acf ("[SCSI] zfcp: Cleanup code in zfcp_erp.c")
removed the use of ZFCP_ERP_ACTION_READY on refactoring
zfcp_erp_action_exists() to now only check adapter->erp_running_head but no
longer adapter->erp_ready_head. The same commit could have changed the
function return type from int to "enum zfcp_erp_act_state".
ZFCP_ERP_ACTION_READY was never used outside of zfcp_erp_action_exists().

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>
2018-05-18 11:28:12 -04:00
Steffen Maier d39eda54b7 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 f76af7d7e3 ("[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 287ac01acf ("[SCSI] zfcp: Cleanup
code in zfcp_erp.c") which introduced status_change_set().

FC changes complement v2.6.32 commit 6f53a2d2ec ("[SCSI] zfcp: Apply
common naming conventions to zfcp_fc").  by renaming a leftover introduced
with v2.6.27 commit cc8c282963 ("[SCSI] zfcp: Automatically attach remote
ports").

FSF changes fixup v2.6.32 commit a4623c467f ("[SCSI] zfcp: Improve request
allocation through mempools").  which replaced zfcp_fsf_alloc_qtcb()
introduced with v2.6.27 commit c41f8cbddd ("[SCSI] zfcp: zfcp_fsf
cleanup.").

SCSI fc_host statistics were introduced with v2.6.16 commit f6cd94b126
("[SCSI] zfcp: transport class adaptations").

SCSI fc_host port_state was introduced with v2.6.27 commit 85a82392fe
("[SCSI] zfcp: Add port_state attribute to sysfs").

SCSI rport setter for dev_loss_tmo was introduced with v2.6.18 commit
338151e066 ("[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>
2018-05-18 11:28:12 -04:00
Steffen Maier 5c750d58e9 scsi: zfcp: workqueue: set description for port work items with their WWPN as context
As a prerequisite, complement commit 3d1cb2059d ("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 ef3b101925 ("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>
2018-05-18 11:27:21 -04:00
Steffen Maier 674595d851 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>
2018-05-18 11:22:11 -04:00
Steffen Maier 42afc6527d 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 379d6bf657 ("[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 6f2ce1c6af ("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>
2018-05-18 11:22:11 -04:00
Steffen Maier 26f5fa9d47 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>
2018-05-18 11:22:11 -04:00
Steffen Maier 39abb11aca scsi: zfcp: decouple FSF request setup of TMF from scsi_cmnd
In zfcp_fsf_fcp_task_mgmt() resolve the still old argument scsi_cmnd into
scsi_device very early and only depend on scsi_device and derived objects in
the function body.

This prepares to later change the function signature replacing the scsi_cmnd
argument with scsi_device.

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>
2018-05-18 11:22:11 -04:00
Steffen Maier e0116c91c7 scsi: zfcp: split FCP_CMND IU setup between SCSI I/O and TMF again
This reverts commit 2443c8b23a ("[SCSI] zfcp: Merge FCP task management
setup with regular FCP command setup"), because this introduced a
dependency on the unsuitable SCSI command for scsi_eh / TMF.

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-05-18 11:22:11 -04:00