Commit graph

185 commits

Author SHA1 Message Date
Julian Wiedmann
addf137296 scsi: zfcp: Use list_first_entry_or_null() in zfcp_erp_thread()
Use the right helper to avoid poking around in the list's internals.

Link: https://lore.kernel.org/r/ed669555c73aab95b29444c10066f492c0c43391.1599765652.git.bblock@linux.ibm.com
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-09-15 18:01:57 -04:00
Linus Torvalds
dfdf16ecfd SCSI misc on 20200806
This series consists of the usual driver updates (ufs, qla2xxx, tcmu,
 lpfc, hpsa, zfcp, scsi_debug) and minor bug fixes.  We also have a
 huge docbook fix update like most other subsystems and no major update
 to the core (the few non trivial updates are either minor fixes or
 removing an unused feature [scsi_sdb_cache]).
 
 Signed-off-by: James E.J. Bottomley <jejb@linux.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 consists of the usual driver updates (ufs, qla2xxx, tcmu, lpfc,
  hpsa, zfcp, scsi_debug) and minor bug fixes.

  We also have a huge docbook fix update like most other subsystems and
  no major update to the core (the few non trivial updates are either
  minor fixes or removing an unused feature [scsi_sdb_cache])"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (307 commits)
  scsi: scsi_transport_srp: Sanitize scsi_target_block/unblock sequences
  scsi: ufs-mediatek: Apply DELAY_AFTER_LPM quirk to Micron devices
  scsi: ufs: Introduce device quirk "DELAY_AFTER_LPM"
  scsi: virtio-scsi: Correctly handle the case where all LUNs are unplugged
  scsi: scsi_debug: Implement tur_ms_to_ready parameter
  scsi: scsi_debug: Fix request sense
  scsi: lpfc: Fix typo in comment for ULP
  scsi: ufs-mediatek: Prevent LPM operation on undeclared VCC
  scsi: iscsi: Do not put host in iscsi_set_flashnode_param()
  scsi: hpsa: Correct ctrl queue depth
  scsi: target: tcmu: Make TMR notification optional
  scsi: target: tcmu: Implement tmr_notify callback
  scsi: target: tcmu: Fix and simplify timeout handling
  scsi: target: tcmu: Factor out new helper ring_insert_padding
  scsi: target: tcmu: Do not queue aborted commands
  scsi: target: tcmu: Use priv pointer in se_cmd
  scsi: target: Add tmr_notify backend function
  scsi: target: Modify core_tmr_abort_task()
  scsi: target: iscsi: Fix inconsistent debug message
  scsi: target: iscsi: Fix login error when receiving
  ...
2020-08-06 16:50:07 -07:00
Julian Wiedmann
b43cdb5ac8 scsi: zfcp: Clean up zfcp_erp_action_ready()
We already maintain a pointer to act->adapter. Use it consistently to avoid
any confusion about whose ->erp_ready_head and ->erp_ready_wq we are
accessing.

Link: https://lore.kernel.org/r/d1bb04322f240dee32f4c4a551bc93bc736f4b01.1593780621.git.bblock@linux.ibm.com
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-07-08 00:50:55 -04:00
Steffen Maier
936e6b85da scsi: zfcp: Fix panic on ERP timeout for previously dismissed ERP action
Suppose that, for unrelated reasons, FSF requests on behalf of recovery are
very slow and can run into the ERP timeout.

In the case at hand, we did adapter recovery to a large degree.  However
due to the slowness a LUN open is pending so the corresponding fc_rport
remains blocked.  After fast_io_fail_tmo we trigger close physical port
recovery for the port under which the LUN should have been opened.  The new
higher order port recovery dismisses the pending LUN open ERP action and
dismisses the pending LUN open FSF request.  Such dismissal decouples the
ERP action from the pending corresponding FSF request by setting
zfcp_fsf_req->erp_action to NULL (among other things)
[zfcp_erp_strategy_check_fsfreq()].

If now the ERP timeout for the pending open LUN request runs out, we must
not use zfcp_fsf_req->erp_action in the ERP timeout handler.  This is a
problem since v4.15 commit 75492a5156 ("s390/scsi: Convert timers to use
timer_setup()"). Before that we intentionally only passed zfcp_erp_action
as context argument to zfcp_erp_timeout_handler().

Note: The lifetime of the corresponding zfcp_fsf_req object continues until
a (late) response or an (unrelated) adapter recovery.

Just like the regular response path ignores dismissed requests
[zfcp_fsf_req_complete() => zfcp_fsf_protstatus_eval() => return early] the
ERP timeout handler now needs to ignore dismissed requests.  So simply
return early in the ERP timeout handler if the FSF request is marked as
dismissed in its status flags.  To protect against the race where
zfcp_erp_strategy_check_fsfreq() dismisses and sets
zfcp_fsf_req->erp_action to NULL after our previous status flag check,
return early if zfcp_fsf_req->erp_action is NULL.  After all, the former
ERP action does not need to be woken up as that was already done as part of
the dismissal above [zfcp_erp_action_dismiss()].

This fixes the following panic due to kernel page fault in IRQ context:

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:000009859238c00b R2:00000e3e7ffd000b R3:00000e3e7ffcc007 S:00000e3e7ffd7000 P:000000000000013d
Oops: 0004 ilc:2 [#1] SMP
Modules linked in: ...
CPU: 82 PID: 311273 Comm: stress Kdump: loaded Tainted: G            E  X   ...
Hardware name: IBM 8561 T01 701 (LPAR)
Krnl PSW : 0404c00180000000 001fffff80549be0 (zfcp_erp_notify+0x40/0xc0 [zfcp])
           R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3
Krnl GPRS: 0000000000000080 00000e3d00000000 00000000000000f0 0000000000030000
           000000010028e700 000000000400a39c 000000010028e700 00000e3e7cf87e02
           0000000010000000 0700098591cb67f0 0000000000000000 0000000000000000
           0000033840e9a000 0000000000000000 001fffe008d6bc18 001fffe008d6bbc8
Krnl Code: 001fffff80549bd4: a7180000            lhi     %r1,0
           001fffff80549bd8: 4120a0f0            la      %r2,240(%r10)
          #001fffff80549bdc: a53e0003            llilh   %r3,3
          >001fffff80549be0: ba132000            cs      %r1,%r3,0(%r2)
           001fffff80549be4: a7740037            brc     7,1fffff80549c52
           001fffff80549be8: e320b0180004        lg      %r2,24(%r11)
           001fffff80549bee: e31020e00004        lg      %r1,224(%r2)
           001fffff80549bf4: 412020e0            la      %r2,224(%r2)
Call Trace:
 [<001fffff80549be0>] zfcp_erp_notify+0x40/0xc0 [zfcp]
 [<00000985915e26f0>] call_timer_fn+0x38/0x190
 [<00000985915e2944>] expire_timers+0xfc/0x190
 [<00000985915e2ac4>] run_timer_softirq+0xec/0x218
 [<0000098591ca7c4c>] __do_softirq+0x144/0x398
 [<00000985915110aa>] do_softirq_own_stack+0x72/0x88
 [<0000098591551b58>] irq_exit+0xb0/0xb8
 [<0000098591510c6a>] do_IRQ+0x82/0xb0
 [<0000098591ca7140>] ext_int_handler+0x128/0x12c
 [<0000098591722d98>] clear_subpage.constprop.13+0x38/0x60
([<000009859172ae4c>] clear_huge_page+0xec/0x250)
 [<000009859177e7a2>] do_huge_pmd_anonymous_page+0x32a/0x768
 [<000009859172a712>] __handle_mm_fault+0x88a/0x900
 [<000009859172a860>] handle_mm_fault+0xd8/0x1b0
 [<0000098591529ef6>] do_dat_exception+0x136/0x3e8
 [<0000098591ca6d34>] pgm_check_handler+0x1c8/0x220
Last Breaking-Event-Address:
 [<001fffff80549c88>] zfcp_erp_timeout_handler+0x10/0x18 [zfcp]
Kernel panic - not syncing: Fatal exception in interrupt

Link: https://lore.kernel.org/r/20200623140242.98864-1-maier@linux.ibm.com
Fixes: 75492a5156 ("s390/scsi: Convert timers to use timer_setup()")
Cc: <stable@vger.kernel.org> #4.15+
Reviewed-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-06-24 00:01:09 -04:00
Benjamin Block
d0dff2ac98 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 737eb78e82 ("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 92953c6e0a ("scsi: zfcp: signal incomplete or error for sync exchange config/port data")
commit 7e418833e6 ("scsi: zfcp: diagnostics buffer caching and use for exchange port data")
commit 088210233e ("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>
2020-05-11 23:19:52 -04:00
Benjamin Block
971f2abb4c scsi: zfcp: Fence adapter status propagation for common statuses
Common status flags that all main objects - adapter, port, and unit -
support are propagated to sub-objects when set or cleared. For instance,
when setting the status ZFCP_STATUS_COMMON_ERP_INUSE for an adapter object,
we will propagate this to all its child ports and units - same for when
clearing a common status flag.

Units of an adapter object are enumerated via __shost_for_each_device()
over the scsi host object of the corresponding adapter.

Once we move the scsi host object allocation and registration to after the
first exchange config and exchange port data, this won't be possible for
cases where we set or clear common statuses during the very first adapter
recovery.

But since we won't have any port or unit objects yet at that point of time,
we can just fence the status propagation for cases where the scsi host
object is not yet set in the adapter object. It won't change any effective
status propagations, but will prevent us from dereferencing invalid
pointers.

For any later point in the work flow the scsi host object will be set and
thus nothing is changed then.

Link: https://lore.kernel.org/r/f51fe5f236a1e3d1ce53379c308777561bfe35e1.1588956679.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>
2020-05-11 23:19:50 -04:00
Benjamin Block
ac007adc4d scsi: zfcp: Move p-t-p port allocation to after xport data
When doing the very first adapter recovery - initialization - for a FCP
device in a point-to-point topology we also allocate the port object
corresponding to the attached remote port, and trigger a port recovery for
it that will run after the adapter recovery finished.

Right now this happens right after we finished with the exchange config
data command, and uses the fibre channel host object corresponding to the
FCP device to determine whether a point-to-point topology is used.

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 use of the fc_host object is not
possible anymore at that point in the work flow.

But the allocation and recovery trigger doesn't have notable side-effects
on the following exchange port data processing, so we can move those to
after xport data, and thus also to after the scsi host object allocation,
once we move it. Then the fc_host object can be used again, like it is now.

For any further adapter recoveries this doesn't change anything, because at
that point the port object already exists and recovery is triggered
elsewhere for existing port objects.

Link: https://lore.kernel.org/r/73e5d4ac21e2b37bf0c3ca8e530bc5a5c6e74f8f.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>
2020-05-11 23:19:49 -04:00
Joe Perches
cec9cbac52 scsi: zfcp: use fallthrough;
Convert the various uses of fallthrough comments to fallthrough;

Done via script
Link: https://lore.kernel.org/lkml/b56602fcf79f849e733e7b521bb0e17895d390fa.1582230379.git.joe.com/

Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Fedor Loshakov <loshakov@linux.ibm.com>
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
[bblock@linux.ibm.com: resolved merge conflict with recently upstream-sent patch "zfcp: expose fabric name as common fc_host sysfs attribute"]
Link: https://lore.kernel.org/r/d14669a67a17392490d3184117941123765db1a4.1585663010.git.bblock@linux.ibm.com
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-03-31 22:24:02 -04:00
Steffen Maier
819732be9f scsi: zfcp: fix missing erp_lock in port recovery trigger for point-to-point
v2.6.27 commit cc8c282963 ("[SCSI] zfcp: Automatically attach remote
ports") introduced zfcp automatic port scan.

Before that, the user had to use the sysfs attribute "port_add" of an FCP
device (adapter) to add and open remote (target) ports, even for the remote
peer port in point-to-point topology. That code path did a proper port open
recovery trigger taking the erp_lock.

Since above commit, a new helper function zfcp_erp_open_ptp_port()
performed an UNlocked port open recovery trigger. This can race with other
parallel recovery triggers. In zfcp_erp_action_enqueue() this could corrupt
e.g. adapter->erp_total_count or adapter->erp_ready_head.

As already found for fabric topology in v4.17 commit fa89adba19 ("scsi:
zfcp: fix infinite iteration on ERP ready list"), there was an endless loop
during tracing of rport (un)block.  A subsequent v4.18 commit 9e156c54ac
("scsi: zfcp: assert that the ERP lock is held when tracing a recovery
trigger") introduced a lockdep assertion for that case.

As a side effect, that lockdep assertion now uncovered the unlocked code
path for PtP. It is from within an adapter ERP action:

zfcp_erp_strategy[1479]  intentionally DROPs erp lock around
                         zfcp_erp_strategy_do_action()
zfcp_erp_strategy_do_action[1441]      NO erp lock
zfcp_erp_adapter_strategy[876]         NO erp lock
zfcp_erp_adapter_strategy_open[855]    NO erp lock
zfcp_erp_adapter_strategy_open_fsf[806]NO erp lock
zfcp_erp_adapter_strat_fsf_xconf[772]  erp lock only around
                                       zfcp_erp_action_to_running(),
                                       BUT *_not_* around
                                       zfcp_erp_enqueue_ptp_port()
zfcp_erp_enqueue_ptp_port[728]         BUG: *_not_* taking erp lock
_zfcp_erp_port_reopen[432]             assumes to be called with erp lock
zfcp_erp_action_enqueue[314]           assumes to be called with erp lock
zfcp_dbf_rec_trig[288]                 _checks_ to be called with erp lock:
	lockdep_assert_held(&adapter->erp_lock);

It causes the following lockdep warning:

WARNING: CPU: 2 PID: 775 at drivers/s390/scsi/zfcp_dbf.c:288
                            zfcp_dbf_rec_trig+0x16a/0x188
no locks held by zfcperp0.0.17c0/775.

Fix this by using the proper locked recovery trigger helper function.

Link: https://lore.kernel.org/r/20200312174505.51294-2-maier@linux.ibm.com
Fixes: cc8c282963 ("[SCSI] zfcp: Automatically attach remote ports")
Cc: <stable@vger.kernel.org> #v2.6.27+
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>
2020-03-17 13:12:33 -04:00
Steffen Maier
e76acc5194 scsi: zfcp: proper indentation to reduce confusion in zfcp_erp_required_act
No functional change.

The unary not operator only applies to the sub expression before the
logical or. So we return early if (not running) or failed.

Link: https://lore.kernel.org/r/df4f897f6e83eaa528465d0858d5a22daac47a2f.1572018132.git.bblock@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: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2019-10-28 22:16:15 -04:00
Benjamin Block
4846470888 scsi: zfcp: fix GCC compiler warning emitted with -Wmaybe-uninitialized
GCC v9 emits this warning:
      CC      drivers/s390/scsi/zfcp_erp.o
    drivers/s390/scsi/zfcp_erp.c: In function 'zfcp_erp_action_enqueue':
    drivers/s390/scsi/zfcp_erp.c:217:26: warning: 'erp_action' may be used uninitialized in this function [-Wmaybe-uninitialized]
      217 |  struct zfcp_erp_action *erp_action;
          |                          ^~~~~~~~~~

This is a possible false positive case, as also documented in the GCC
documentations:
    https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html#index-Wmaybe-uninitialized

The actual code-sequence is like this:
    Various callers can invoke the function below with the argument "want"
    being one of:
    ZFCP_ERP_ACTION_REOPEN_ADAPTER,
    ZFCP_ERP_ACTION_REOPEN_PORT_FORCED,
    ZFCP_ERP_ACTION_REOPEN_PORT, or
    ZFCP_ERP_ACTION_REOPEN_LUN.

    zfcp_erp_action_enqueue(want, ...)
        ...
        need = zfcp_erp_required_act(want, ...)
            need = want
            ...
            maybe: need = ZFCP_ERP_ACTION_REOPEN_PORT
            maybe: need = ZFCP_ERP_ACTION_REOPEN_ADAPTER
            ...
            return need
        ...
        zfcp_erp_setup_act(need, ...)
            struct zfcp_erp_action *erp_action; // <== line 217
            ...
            switch(need) {
            case ZFCP_ERP_ACTION_REOPEN_LUN:
                    ...
                    erp_action = &zfcp_sdev->erp_action;
                    WARN_ON_ONCE(erp_action->port != port); // <== access
                    ...
                    break;
            case ZFCP_ERP_ACTION_REOPEN_PORT:
            case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
                    ...
                    erp_action = &port->erp_action;
                    WARN_ON_ONCE(erp_action->port != port); // <== access
                    ...
                    break;
            case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
                    ...
                    erp_action = &adapter->erp_action;
                    WARN_ON_ONCE(erp_action->port != NULL); // <== access
                    ...
                    break;
            }
            ...
            WARN_ON_ONCE(erp_action->adapter != adapter); // <== access

When zfcp_erp_setup_act() is called, 'need' will never be anything else
than one of the 4 possible enumeration-names that are used in the
switch-case, and 'erp_action' is initialized for every one of them, before
it is used. Thus the warning is a false positive, as documented.

We introduce the extra if{} in the beginning to create an extra code-flow,
so the compiler can be convinced that the switch-case will never see any
other value.

BUG_ON()/BUG() is intentionally not used to not crash anything, should
this ever happen anyway - right now it's impossible, as argued above; and
it doesn't introduce a 'default:' switch-case to retain warnings should
'enum zfcp_erp_act_type' ever be extended and no explicit case be
introduced. See also v5.0 commit 399b6c8bc9 ("scsi: zfcp: drop old
default switch case which might paper over missing case").

Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2019-07-11 21:04:23 -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
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
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
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
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
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
6a76550841 scsi: zfcp: fix missing REC trigger trace on enqueue without ERP thread
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            : .......
LUN            : 0x...
WWPN           : 0x...
D_ID           : 0x...
Adapter status : 0x...
Port status    : 0x...
LUN status     : 0x...
Ready count    : 0x...
Running count  : 0x...
ERP want       : 0x0.                   ZFCP_ERP_ACTION_REOPEN_...
ERP need       : 0xc0                   ZFCP_ERP_ACTION_NONE

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
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>
2018-05-18 11:22:11 -04:00
Steffen Maier
8c3d20aada scsi: zfcp: fix missing REC trigger trace for all objects in ERP_FAILED
That other commit introduced an inconsistency because it would trace on
ERP_FAILED for all callers of port forced reopen triggers (not just
terminate_rport_io), but it would not trace on ERP_FAILED for all callers of
other ERP triggers such as adapter, port regular, LUN.

Therefore, generalize that other commit. zfcp_erp_action_enqueue() already
had two early outs which re-used the one zfcp_dbf_rec_trig() call.  All ERP
trigger functions finally run through zfcp_erp_action_enqueue().  So move
the special handling for ZFCP_STATUS_COMMON_ERP_FAILED into
zfcp_erp_action_enqueue() and add another early out with new trace marker
for pseudo ERP need in this case. This removes all early returns from all
ERP trigger functions so we always end up at zfcp_dbf_rec_trig().

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            : .......
LUN            : 0x...
WWPN           : 0x...
D_ID           : 0x...
Adapter status : 0x...
Port status    : 0x...
LUN status     : 0x...
Ready count    : 0x...
Running count  : 0x...
ERP want       : 0x0.                   ZFCP_ERP_ACTION_REOPEN_...
ERP need       : 0xe0                   ZFCP_ERP_ACTION_FAILED

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
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>
2018-05-18 11:22:11 -04:00
Steffen Maier
d70aab5592 scsi: zfcp: fix missing REC trigger trace on terminate_rport_io for ERP_FAILED
For problem determination we always want to see when we were invoked on the
terminate_rport_io callback whether we perform something or not.

Temporal event sequence of interest with a long fast_io_fail_tmo of 27 sec:

loose remote port

t   workqueue
[s] zfcp_q_<dev>       IRQ                 zfcperp<dev>

=== ================== =================== ============================

  0                    recv RSCN
                       q p.test_link_work
    block rport
     start fast_io_fail_tmo
    send ADISC ELS
  4                    recv ADISC fail
                       block zfcp_port
                                           port forced reopen
                                           send open port
 12                    recv open port fail
                                           q p.gid_pn_work
                                           zfcp_erp_wakeup
                                           (zfcp_erp_wait would return)
    GID_PN fail

Before this point, we got a SCSI trace with tag "sctrpi1" on fast_io_fail,
e.g. with the typical 5 sec setting.

    port.status |= ERP_FAILED

If fast_io_fail_tmo triggers after this point, we missed a SCSI trace.

    workqueue
    fc_dl_<host>
    ==================
 27 fc_timeout_fail_rport_io
    fc_terminate_rport_io
    zfcp_scsi_terminate_rport_io
    zfcp_erp_port_forced_reopen
    _zfcp_erp_port_forced_reopen
     if (port.status & ERP_FAILED)
      return;

Therefore, write a trace before above early return.

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            : sctrpi1                SCSI terminate rport I/O
LUN            : 0xffffffffffffffff                     none (invalid)
WWPN           : 0x<wwpn>
D_ID           : 0x<n_port_id>
Adapter status : 0x...
Port status    : 0x...
LUN status     : 0x00000000                             none (invalid)
Ready count    : 0x...
Running count  : 0x...
ERP want       : 0x03                   ZFCP_ERP_ACTION_REOPEN_PORT_FORCED
ERP need       : 0xe0                   ZFCP_ERP_ACTION_FAILED

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
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>
2018-05-18 11:22:10 -04:00
Steffen Maier
96d9270499 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
70932935b6 ("[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: 70932935b6 ("[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>
2018-05-18 11:22:10 -04:00
Steffen Maier
512857a795 scsi: zfcp: fix misleading REC trigger trace where erp_action setup failed
If a SCSI device is deleted during scsi_eh host reset, we cannot get a
reference to the SCSI device anymore since scsi_device_get returns !=0 by
design. Assuming the recovery of adapter and port(s) was successful,
zfcp_erp_strategy_followup_success() attempts to trigger a LUN reset for the
half-gone SCSI device. Unfortunately, it causes the following confusing
trace record which states that zfcp will do a LUN recovery as "ERP need" is
ZFCP_ERP_ACTION_REOPEN_LUN == 1 and equals "ERP want".

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

Tag:           : ersfs_3 ERP, trigger, unit reopen, port reopen succeeded
LUN            : 0x<FCP_LUN>
WWPN           : 0x<WWPN>
D_ID           : 0x<N_Port-ID>
Adapter status : 0x5400050b
Port status    : 0x54000001
LUN status     : 0x40000000     ZFCP_STATUS_COMMON_RUNNING
                                but not ZFCP_STATUS_COMMON_UNBLOCKED as it
                                was closed on close part of adapter reopen
ERP want       : 0x01
ERP need       : 0x01           misleading

However, zfcp_erp_setup_act() returns NULL as it cannot get the reference.
Hence, zfcp_erp_action_enqueue() takes an early goto out and _NO_ recovery
actually happens.

We always do want the recovery trigger trace record even if no erp_action
could be enqueued as in this case. For other cases where we did not enqueue
an erp_action, 'need' has always been zero to indicate this. In order to
indicate above goto out, introduce an eyecatcher "flag" to mark the "ERP
need" as 'not needed' but still keep the information which erp_action type,
that zfcp_erp_required_act() had decided upon, is needed.  0xc_ is chosen to
be visibly different from 0x0_ in "ERP want".

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

Tag:           : ersfs_3 ERP, trigger, unit reopen, port reopen succeeded
LUN            : 0x<FCP_LUN>
WWPN           : 0x<WWPN>
D_ID           : 0x<N_Port-ID>
Adapter status : 0x5400050b
Port status    : 0x54000001
LUN status     : 0x40000000
ERP want       : 0x01
ERP need       : 0xc1           would need LUN ERP, but no action set up
                   ^

Before v2.6.38 commit ae0904f60f ("[SCSI] zfcp: Redesign of the debug
tracing for recovery actions.") we could detect this case because the
"erp_action" field in the trace was NULL. The rework removed erp_action as
argument and field from the trace.

This patch here is for tracing. A fix to allow LUN recovery in the case at
hand is a topic for a separate patch.

See also commit fdbd1c5e27 ("[SCSI] zfcp: Allow running unit/LUN shutdown
without acquiring reference") for a similar case and background info.

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Fixes: ae0904f60f ("[SCSI] zfcp: Redesign of the debug tracing for recovery actions.")
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>
2018-05-18 11:22:10 -04:00
Steffen Maier
5c13db9b5d zfcp: purely mechanical update using timer API, plus blank lines
erp_memwait only occurs in seldom memory pressure situations.
The typical case never uses the associated timer and thus also
does not need to initialize the timer.
Also, we don't want to re-initialize the timer each time we re-use an
erp_action in zfcp_erp_setup_act() [see also v4.14-rc7 commit ab31fd0ce6
("scsi: zfcp: fix erp_action use-before-initialize in REC action trace")
for erp_action life cycle].
Hence, retain the lazy inintialization of zfcp_erp_action.timer
in zfcp_erp_strategy_memwait().

Add an empty line after declarations in zfcp_erp_timeout_handler()
and zfcp_fsf_request_timeout_handler() even though it was also missing
before the timer conversion.

Fix checkpatch warning:
WARNING: function definition argument 'struct timer_list *' should also have an identifier name
+extern void zfcp_erp_timeout_handler(struct timer_list *);

Depends-on: v4.14-rc3 commit 686fef928b ("timer: Prepare to change timer callback argument type")
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-16 15:06:19 +01:00
Kees Cook
75492a5156 s390/scsi: Convert timers to use timer_setup()
In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.

Cc: Steffen Maier <maier@linux.vnet.ibm.com>
Cc: Benjamin Block <bblock@linux.vnet.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux-s390@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-16 15:06:17 +01:00
Linus Torvalds
ead751507d License cleanup: add SPDX license identifiers to some files
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>
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Merge tag 'spdx_identifiers-4.14-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull initial SPDX identifiers from Greg KH:
 "License cleanup: add SPDX license identifiers to some files

  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>"

* tag 'spdx_identifiers-4.14-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  License cleanup: add SPDX license identifier to uapi header files with a license
  License cleanup: add SPDX license identifier to uapi header files with no license
  License cleanup: add SPDX GPL-2.0 license identifier to files with no license
2017-11-02 10:04:46 -07:00
Greg Kroah-Hartman
b24413180f 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>
2017-11-02 11:10:55 +01:00
Steffen Maier
ab31fd0ce6 scsi: zfcp: fix erp_action use-before-initialize in REC action trace
v4.10 commit 6f2ce1c6af ("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: 6f2ce1c6af ("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>
2017-10-16 22:45:26 -04:00
Lukáš Korenčik
bc46427e80 scsi: zfcp: use setup_timer instead of init_timer
Use initialization with setup_timer function instead of using
init_timer function and data fields. It improves readability.

Signed-off-by: Lukáš Korenčik <xkorenc1@fi.muni.cz>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2017-08-10 19:36:53 -04:00
Steffen Maier
6f2ce1c6af 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: 8830271c48 ("[SCSI] zfcp: Dont fail SCSI commands when transitioning to blocked fc_rport")
Fixes: a2fa0aede0 ("[SCSI] zfcp: Block FC transport rports early on errors")
Fixes: 5f852be9e1 ("[SCSI] zfcp: Fix deadlock between zfcp ERP and SCSI")
Fixes: 338151e066 ("[SCSI] zfcp: make use of fc_remote_port_delete when target port is unavailable")
Fixes: 3859f6a248 ("[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>
2016-12-14 15:17:20 -05:00
Steffen Maier
4eeaa4f3f1 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: 5767620c38 ("[SCSI] zfcp: Do not unblock rport from REOPEN_PORT_FORCED")
Fixes: a2fa0aede0 ("[SCSI] zfcp: Block FC transport rports early on errors")
Fixes: 5f852be9e1 ("[SCSI] zfcp: Fix deadlock between zfcp ERP and SCSI")
Fixes: 338151e066 ("[SCSI] zfcp: make use of fc_remote_port_delete when target port is unavailable")
Fixes: 3859f6a248 ("[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>
2016-08-12 16:17:12 -04:00
Peter Zijlstra
805de8f43c atomic: Replace atomic_{set,clear}_mask() usage
Replace the deprecated atomic_{set,clear}_mask() usage with the now
ubiquous atomic_{or,andnot}() functions.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-07-27 14:06:24 +02:00
David Rientjes
11d8336045 mm, mempool: do not allow atomic resizing
Allocating a large number of elements in atomic context could quickly
deplete memory reserves, so just disallow atomic resizing entirely.

Nothing currently uses mempool_resize() with anything other than
GFP_KERNEL, so convert existing callers to drop the gfp_mask.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Steffen Maier <maier@linux.vnet.ibm.com>	[zfcp]
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Steve French <sfrench@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14 16:49:06 -07:00
Martin Peschke
1b33ef2394 zfcp: remove access control tables interface (port leftovers)
This patch removes some leftovers for commit
663e0890e3
"[SCSI] zfcp: remove access control tables interface".

The "access denied" case for ports is gone, as well.
The corresponding flag was cleared, but never set.
So clean it up.

Sysfs flag is kept, though, for backward-compatibility.
Now it returns always 0.

Signed-off-by: Martin Peschke <mpeschke@linux.vnet.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2014-11-20 09:11:28 +01:00
Martin Peschke
924dd584b1 [SCSI] zfcp: fix schedule-inside-lock in scsi_device list loops
BUG: sleeping function called from invalid context at kernel/workqueue.c:2752
in_atomic(): 1, irqs_disabled(): 1, pid: 360, name: zfcperp0.0.1700
CPU: 1 Not tainted 3.9.3+ #69
Process zfcperp0.0.1700 (pid: 360, task: 0000000075b7e080, ksp: 000000007476bc30)
<snip>
Call Trace:
([<00000000001165de>] show_trace+0x106/0x154)
 [<00000000001166a0>] show_stack+0x74/0xf4
 [<00000000006ff646>] dump_stack+0xc6/0xd4
 [<000000000017f3a0>] __might_sleep+0x128/0x148
 [<000000000015ece8>] flush_work+0x54/0x1f8
 [<00000000001630de>] __cancel_work_timer+0xc6/0x128
 [<00000000005067ac>] scsi_device_dev_release_usercontext+0x164/0x23c
 [<0000000000161816>] execute_in_process_context+0x96/0xa8
 [<00000000004d33d8>] device_release+0x60/0xc0
 [<000000000048af48>] kobject_release+0xa8/0x1c4
 [<00000000004f4bf2>] __scsi_iterate_devices+0xfa/0x130
 [<000003ff801b307a>] zfcp_erp_strategy+0x4da/0x1014 [zfcp]
 [<000003ff801b3caa>] zfcp_erp_thread+0xf6/0x2b0 [zfcp]
 [<000000000016b75a>] kthread+0xf2/0xfc
 [<000000000070c9de>] kernel_thread_starter+0x6/0xc
 [<000000000070c9d8>] kernel_thread_starter+0x0/0xc

Apparently, the ref_count for some scsi_device drops down to zero,
triggering device removal through execute_in_process_context(), while
the lldd error recovery thread iterates through a scsi device list.
Unfortunately, execute_in_process_context() decides to immediately
execute that device removal function, instead of scheduling asynchronous
execution, since it detects process context and thinks it is safe to do
so. But almost all calls to shost_for_each_device() in our lldd are
inside spin_lock_irq, even in thread context. Obviously, schedule()
inside spin_lock_irq sections is a bad idea.

Change the lldd to use the proper iterator function,
__shost_for_each_device(), in combination with required locking.

Occurences that need to be changed include all calls in zfcp_erp.c,
since those might be executed in zfcp error recovery thread context
with a lock held.

Other occurences of shost_for_each_device() in zfcp_fsf.c do not
need to be changed (no process context, no surrounding locking).

The problem was introduced in Linux 2.6.37 by commit
b62a8d9b45
"[SCSI] zfcp: Use SCSI device data zfcp_scsi_dev instead of zfcp_unit".

Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Peschke <mpeschke@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org #2.6.37+
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-08-22 09:24:02 -07:00
Martin Peschke
663e0890e3 [SCSI] zfcp: remove access control tables interface
This patch removes an interface that was used to manage access control
tables within the HBA. The patch consequently removes the handling
for conditions related to those access control tables, too.

That initiator-based access control feature was only needed until the
introduction of NPIV and was withdrawn with z10 years ago.
It's time to cleanup the corresponding device driver code.

Signed-off-by: Martin Peschke <mpeschke@linux.vnet.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-05-31 16:32:38 -07:00
Steffen Maier
43f60cbd56 [SCSI] zfcp: No automatic port_rescan on events
In FC fabrics with large zones, the automatic port_rescan on incoming ELS
and any adapter recovery can cause quite some traffic at the very same
time, especially if lots of Linux images share an HBA, which is common on
s390. This can cause trouble and failures. Fix this by making such port
rescans dependent on a user configurable module parameter.

The following unconditional automatic port rescans remain as is:
On setting an adapter online and
on manual user-triggered writes to the sysfs attribute port_rescan.

Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-09-24 12:11:02 +04:00
Heiko Carstens
a53c8fab3f 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>
2012-07-20 11:15:04 +02:00
Christof Schmitt
038d9446a9 [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>
2011-02-25 12:02:21 -05:00
Christof Schmitt
c7b279ae51 [SCSI] zfcp: Replace kmem_cache for "status read" data
zfcp requires a mempool for the status read data blocks to resubmit
the "status read" requests at any time. Each status read data block
has the size of a page (4096 bytes) and needs to be placed in one
page.

Instead of having a kmem_cache for allocating page sized chunks, use
mempool_create_page_pool to create a mempool returning pages and
remove the zfcp kmem_cache.

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>
2011-02-25 12:01:59 -05:00
Christof Schmitt
3d63d3b4fb [SCSI] zfcp: Move qdio setup from erp to zfcp_qdio.c
Initialization of the qdio waitqueue should happen when the qdio data
is initialized and the QDIOUP flag should be handled in the qdio code
as well. Adjust the code accordingly and remove the superfluos
function zfcp_erp_adapter_strategy_open_qdio.

Reviewed-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2010-12-21 12:24:47 -06:00