Commit Graph

284 Commits

Author SHA1 Message Date
Benjamin Block
0954256e97 scsi: zfcp: Fix double free of FSF request when qdio send fails
We used to use the wrong type of integer in 'zfcp_fsf_req_send()' to cache
the FSF request ID when sending a new FSF request. This is used in case the
sending fails and we need to remove the request from our internal hash
table again (so we don't keep an invalid reference and use it when we free
the request again).

In 'zfcp_fsf_req_send()' we used to cache the ID as 'int' (signed and 32
bit wide), but the rest of the zfcp code (and the firmware specification)
handles the ID as 'unsigned long'/'u64' (unsigned and 64 bit wide [s390x
ELF ABI]).  For one this has the obvious problem that when the ID grows
past 32 bit (this can happen reasonably fast) it is truncated to 32 bit
when storing it in the cache variable and so doesn't match the original ID
anymore.  The second less obvious problem is that even when the original ID
has not yet grown past 32 bit, as soon as the 32nd bit is set in the
original ID (0x80000000 = 2'147'483'648) we will have a mismatch when we
cast it back to 'unsigned long'. As the cached variable is of a signed
type, the compiler will choose a sign-extending instruction to load the 32
bit variable into a 64 bit register (e.g.: 'lgf %r11,188(%r15)'). So once
we pass the cached variable into 'zfcp_reqlist_find_rm()' to remove the
request again all the leading zeros will be flipped to ones to extend the
sign and won't match the original ID anymore (this has been observed in
practice).

If we can't successfully remove the request from the hash table again after
'zfcp_qdio_send()' fails (this happens regularly when zfcp cannot notify
the adapter about new work because the adapter is already gone during
e.g. a ChpID toggle) we will end up with a double free.  We unconditionally
free the request in the calling function when 'zfcp_fsf_req_send()' fails,
but because the request is still in the hash table we end up with a stale
memory reference, and once the zfcp adapter is either reset during recovery
or shutdown we end up freeing the same memory twice.

The resulting stack traces vary depending on the kernel and have no direct
correlation to the place where the bug occurs. Here are three examples that
have been seen in practice:

  list_del corruption. next->prev should be 00000001b9d13800, but was 00000000dead4ead. (next=00000001bd131a00)
  ------------[ cut here ]------------
  kernel BUG at lib/list_debug.c:62!
  monitor event: 0040 ilc:2 [#1] PREEMPT SMP
  Modules linked in: ...
  CPU: 9 PID: 1617 Comm: zfcperp0.0.1740 Kdump: loaded
  Hardware name: ...
  Krnl PSW : 0704d00180000000 00000003cbeea1f8 (__list_del_entry_valid+0x98/0x140)
             R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:1 PM:0 RI:0 EA:3
  Krnl GPRS: 00000000916d12f1 0000000080000000 000000000000006d 00000003cb665cd6
             0000000000000001 0000000000000000 0000000000000000 00000000d28d21e8
             00000000d3844000 00000380099efd28 00000001bd131a00 00000001b9d13800
             00000000d3290100 0000000000000000 00000003cbeea1f4 00000380099efc70
  Krnl Code: 00000003cbeea1e8: c020004f68a7        larl    %r2,00000003cc8d7336
             00000003cbeea1ee: c0e50027fd65        brasl   %r14,00000003cc3e9cb8
            #00000003cbeea1f4: af000000            mc      0,0
            >00000003cbeea1f8: c02000920440        larl    %r2,00000003cd12aa78
             00000003cbeea1fe: c0e500289c25        brasl   %r14,00000003cc3fda48
             00000003cbeea204: b9040043            lgr     %r4,%r3
             00000003cbeea208: b9040051            lgr     %r5,%r1
             00000003cbeea20c: b9040032            lgr     %r3,%r2
  Call Trace:
   [<00000003cbeea1f8>] __list_del_entry_valid+0x98/0x140
  ([<00000003cbeea1f4>] __list_del_entry_valid+0x94/0x140)
   [<000003ff7ff502fe>] zfcp_fsf_req_dismiss_all+0xde/0x150 [zfcp]
   [<000003ff7ff49cd0>] zfcp_erp_strategy_do_action+0x160/0x280 [zfcp]
   [<000003ff7ff4a22e>] zfcp_erp_strategy+0x21e/0xca0 [zfcp]
   [<000003ff7ff4ad34>] zfcp_erp_thread+0x84/0x1a0 [zfcp]
   [<00000003cb5eece8>] kthread+0x138/0x150
   [<00000003cb557f3c>] __ret_from_fork+0x3c/0x60
   [<00000003cc4172ea>] ret_from_fork+0xa/0x40
  INFO: lockdep is turned off.
  Last Breaking-Event-Address:
   [<00000003cc3e9d04>] _printk+0x4c/0x58
  Kernel panic - not syncing: Fatal exception: panic_on_oops

or:

  Unable to handle kernel pointer dereference in virtual kernel address space
  Failing address: 6b6b6b6b6b6b6000 TEID: 6b6b6b6b6b6b6803
  Fault in home space mode while using kernel ASCE.
  AS:0000000063b10007 R3:0000000000000024
  Oops: 0038 ilc:3 [#1] SMP
  Modules linked in: ...
  CPU: 10 PID: 0 Comm: swapper/10 Kdump: loaded
  Hardware name: ...
  Krnl PSW : 0404d00180000000 000003ff7febaf8e (zfcp_fsf_reqid_check+0x86/0x158 [zfcp])
             R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:3 CC:1 PM:0 RI:0 EA:3
  Krnl GPRS: 5a6f1cfa89c49ac3 00000000aff2c4c8 6b6b6b6b6b6b6b6b 00000000000002a8
             0000000000000000 0000000000000055 0000000000000000 00000000a8515800
             0700000000000000 00000000a6e14500 00000000aff2c000 000000008003c44c
             000000008093c700 0000000000000010 00000380009ebba8 00000380009ebb48
  Krnl Code: 000003ff7febaf7e: a7f4003d            brc     15,000003ff7febaff8
             000003ff7febaf82: e32020000004        lg      %r2,0(%r2)
            #000003ff7febaf88: ec2100388064        cgrj    %r2,%r1,8,000003ff7febaff8
            >000003ff7febaf8e: e3b020100020        cg      %r11,16(%r2)
             000003ff7febaf94: a774fff7            brc     7,000003ff7febaf82
             000003ff7febaf98: ec280030007c        cgij    %r2,0,8,000003ff7febaff8
             000003ff7febaf9e: e31020080004        lg      %r1,8(%r2)
             000003ff7febafa4: e33020000004        lg      %r3,0(%r2)
  Call Trace:
   [<000003ff7febaf8e>] zfcp_fsf_reqid_check+0x86/0x158 [zfcp]
   [<000003ff7febbdbc>] zfcp_qdio_int_resp+0x6c/0x170 [zfcp]
   [<000003ff7febbf90>] zfcp_qdio_irq_tasklet+0xd0/0x108 [zfcp]
   [<0000000061d90a04>] tasklet_action_common.constprop.0+0xdc/0x128
   [<000000006292f300>] __do_softirq+0x130/0x3c0
   [<0000000061d906c6>] irq_exit_rcu+0xfe/0x118
   [<000000006291e818>] do_io_irq+0xc8/0x168
   [<000000006292d516>] io_int_handler+0xd6/0x110
   [<000000006292d596>] psw_idle_exit+0x0/0xa
  ([<0000000061d3be50>] arch_cpu_idle+0x40/0xd0)
   [<000000006292ceea>] default_idle_call+0x52/0xf8
   [<0000000061de4fa4>] do_idle+0xd4/0x168
   [<0000000061de51fe>] cpu_startup_entry+0x36/0x40
   [<0000000061d4faac>] smp_start_secondary+0x12c/0x138
   [<000000006292d88e>] restart_int_handler+0x6e/0x90
  Last Breaking-Event-Address:
   [<000003ff7febaf94>] zfcp_fsf_reqid_check+0x8c/0x158 [zfcp]
  Kernel panic - not syncing: Fatal exception in interrupt

or:

  Unable to handle kernel pointer dereference in virtual kernel address space
  Failing address: 523b05d3ae76a000 TEID: 523b05d3ae76a803
  Fault in home space mode while using kernel ASCE.
  AS:0000000077c40007 R3:0000000000000024
  Oops: 0038 ilc:3 [#1] SMP
  Modules linked in: ...
  CPU: 3 PID: 453 Comm: kworker/3:1H Kdump: loaded
  Hardware name: ...
  Workqueue: kblockd blk_mq_run_work_fn
  Krnl PSW : 0404d00180000000 0000000076fc0312 (__kmalloc+0xd2/0x398)
             R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:3 CC:1 PM:0 RI:0 EA:3
  Krnl GPRS: ffffffffffffffff 523b05d3ae76abf6 0000000000000000 0000000000092a20
             0000000000000002 00000007e49b5cc0 00000007eda8f000 0000000000092a20
             00000007eda8f000 00000003b02856b9 00000000000000a8 523b05d3ae76abf6
             00000007dd662000 00000007eda8f000 0000000076fc02b2 000003e0037637a0
  Krnl Code: 0000000076fc0302: c004000000d4	brcl	0,76fc04aa
             0000000076fc0308: b904001b		lgr	%r1,%r11
            #0000000076fc030c: e3106020001a	algf	%r1,32(%r6)
            >0000000076fc0312: e31010000082	xg	%r1,0(%r1)
             0000000076fc0318: b9040001		lgr	%r0,%r1
             0000000076fc031c: e30061700082	xg	%r0,368(%r6)
             0000000076fc0322: ec59000100d9	aghik	%r5,%r9,1
             0000000076fc0328: e34003b80004	lg	%r4,952
  Call Trace:
   [<0000000076fc0312>] __kmalloc+0xd2/0x398
   [<0000000076f318f2>] mempool_alloc+0x72/0x1f8
   [<000003ff8027c5f8>] zfcp_fsf_req_create.isra.7+0x40/0x268 [zfcp]
   [<000003ff8027f1bc>] zfcp_fsf_fcp_cmnd+0xac/0x3f0 [zfcp]
   [<000003ff80280f1a>] zfcp_scsi_queuecommand+0x122/0x1d0 [zfcp]
   [<000003ff800b4218>] scsi_queue_rq+0x778/0xa10 [scsi_mod]
   [<00000000771782a0>] __blk_mq_try_issue_directly+0x130/0x208
   [<000000007717a124>] blk_mq_request_issue_directly+0x4c/0xa8
   [<000003ff801302e2>] dm_mq_queue_rq+0x2ea/0x468 [dm_mod]
   [<0000000077178c12>] blk_mq_dispatch_rq_list+0x33a/0x818
   [<000000007717f064>] __blk_mq_do_dispatch_sched+0x284/0x2f0
   [<000000007717f44c>] __blk_mq_sched_dispatch_requests+0x1c4/0x218
   [<000000007717fa7a>] blk_mq_sched_dispatch_requests+0x52/0x90
   [<0000000077176d74>] __blk_mq_run_hw_queue+0x9c/0xc0
   [<0000000076da6d74>] process_one_work+0x274/0x4d0
   [<0000000076da7018>] worker_thread+0x48/0x560
   [<0000000076daef18>] kthread+0x140/0x160
   [<000000007751d144>] ret_from_fork+0x28/0x30
  Last Breaking-Event-Address:
   [<0000000076fc0474>] __kmalloc+0x234/0x398
  Kernel panic - not syncing: Fatal exception: panic_on_oops

To fix this, simply change the type of the cache variable to 'unsigned
long', like the rest of zfcp and also the argument for
'zfcp_reqlist_find_rm()'. This prevents truncation and wrong sign extension
and so can successfully remove the request from the hash table.

Fixes: e60a6d69f1 ("[SCSI] zfcp: Remove function zfcp_reqlist_find_safe")
Cc: <stable@vger.kernel.org> #v2.6.34+
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Link: https://lore.kernel.org/r/979f6e6019d15f91ba56182f1aaf68d61bf37fc6.1668595505.git.bblock@linux.ibm.com
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2022-11-17 17:51:06 +00:00
Steffen Maier
4da8c5f768 scsi: zfcp: Fix missing auto port scan and thus missing target ports
Case (1):
  The only waiter on wka_port->completion_wq is zfcp_fc_wka_port_get()
  trying to open a WKA port. As such it should only be woken up by WKA port
  *open* responses, not by WKA port close responses.

Case (2):
  A close WKA port response coming in just after having sent a new open WKA
  port request and before blocking for the open response with wait_event()
  in zfcp_fc_wka_port_get() erroneously renders the wait_event a NOP
  because the close handler overwrites wka_port->status. Hence the
  wait_event condition is erroneously true and it does not enter blocking
  state.

With non-negligible probability, the following time space sequence happens
depending on timing without this fix:

user process        ERP thread zfcp work queue tasklet system work queue
============        ========== =============== ======= =================
$ echo 1 > online
zfcp_ccw_set_online
zfcp_ccw_activate
zfcp_erp_adapter_reopen
msleep scan backoff zfcp_erp_strategy
|                   ...
|                   zfcp_erp_action_cleanup
|                   ...
|                   queue delayed scan_work
|                   queue ns_up_work
|                              ns_up_work:
|                              zfcp_fc_wka_port_get
|                               open wka request
|                                              open response
|                              GSPN FC-GS
|                              RSPN FC-GS [NPIV-only]
|                              zfcp_fc_wka_port_put
|                               (--wka->refcount==0)
|                               sched delayed wka->work
|
~~~Case (1)~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
zfcp_erp_wait
flush scan_work
|                                                      wka->work:
|                                                      wka->status=CLOSING
|                                                      close wka request
|                              scan_work:
|                              zfcp_fc_wka_port_get
|                               (wka->status==CLOSING)
|                               wka->status=OPENING
|                               open wka request
|                               wait_event
|                               |              close response
|                               |              wka->status=OFFLINE
|                               |              wake_up /*WRONG*/
~~~Case (2)~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|                                                      wka->work:
|                                                      wka->status=CLOSING
|                                                      close wka request
zfcp_erp_wait
flush scan_work
|                              scan_work:
|                              zfcp_fc_wka_port_get
|                               (wka->status==CLOSING)
|                               wka->status=OPENING
|                               open wka request
|                                              close response
|                                              wka->status=OFFLINE
|                                              wake_up /*WRONG&NOP*/
|                               wait_event /*NOP*/
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|                               (wka->status!=ONLINE)
|                               return -EIO
|                              return early
                                               open response
                                               wka->status=ONLINE
                                               wake_up /*NOP*/

So we erroneously end up with no automatic port scan. This is a big problem
when it happens during boot. The timing is influenced by v3.19 commit
18f87a67e6 ("zfcp: auto port scan resiliency").

Fix it by fully mutually excluding zfcp_fc_wka_port_get() and
zfcp_fc_wka_port_offline(). For that to work, we make the latter block
until we got the response for a close WKA port. In order not to penalize
the system workqueue, we move wka_port->work to our own adapter workqueue.
Note that before v2.6.30 commit 828bc1212a ("[SCSI] zfcp: Set WKA-port to
offline on adapter deactivation"), zfcp did block in
zfcp_fc_wka_port_offline() as well, but with a different condition.

While at it, make non-functional cleanups to improve code reading in
zfcp_fc_wka_port_get(). If we cannot send the WKA port open request, don't
rely on the subsequent wait_event condition to immediately let this case
pass without blocking. Also don't want to rely on the additional condition
handling the refcount to be skipped just to finally return with -EIO.

Link: https://lore.kernel.org/r/20220729162529.1620730-1-maier@linux.ibm.com
Fixes: 5ab944f97e ("[SCSI] zfcp: attach and release SAN nameserver port on demand")
Cc: <stable@vger.kernel.org> #v2.6.28+
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>
2022-08-01 19:50:00 -04:00
Bart Van Assche
68f89c50cd scsi: zfcp_scsi: Call scsi_done() directly
Conditional statements are faster than indirect calls. Hence call
scsi_done() directly.

Link: https://lore.kernel.org/r/20211007202923.2174984-8-bvanassche@acm.org
Acked-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-10-16 21:28:44 -04:00
Linus Torvalds
f154c80667 2nd batch of s390 updates for 5.15 merge window
- Fix topology update on cpu hotplug, so notifiers see expected masks. This bug
   was uncovered with SCHED_CORE support.
 
 - Fix stack unwinding so that the correct number of entries are omitted like
   expected by common code. This fixes KCSAN selftests.
 
 - Add kmemleak annotation to stack_alloc to avoid false positive kmemleak
   warnings.
 
 - Avoid layering violation in common I/O code and don't unregister subchannel
   from child-drivers.
 
 - Remove xpram device driver for which no real use case exists since the kernel
   is 64 bit only. Also all hypervisors got required support removed in the
   meantime, which means the xpram device driver is dead code.
 
 - Fix -ENODEV handling of clp_get_state in our PCI code.
 
 - Enable KFENCE in debug defconfig.
 
 - Cleanup hugetlbfs s390 specific Kconfig dependency.
 
 - Quite a lot of trivial fixes to get rid of "W=1" warnings, and and other
   simple cleanups.
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Merge tag 's390-5.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull more s390 updates from Heiko Carstens:
 "Except for the xpram device driver removal it is all about fixes and
  cleanups.

   - Fix topology update on cpu hotplug, so notifiers see expected
     masks. This bug was uncovered with SCHED_CORE support.

   - Fix stack unwinding so that the correct number of entries are
     omitted like expected by common code. This fixes KCSAN selftests.

   - Add kmemleak annotation to stack_alloc to avoid false positive
     kmemleak warnings.

   - Avoid layering violation in common I/O code and don't unregister
     subchannel from child-drivers.

   - Remove xpram device driver for which no real use case exists since
     the kernel is 64 bit only. Also all hypervisors got required
     support removed in the meantime, which means the xpram device
     driver is dead code.

   - Fix -ENODEV handling of clp_get_state in our PCI code.

   - Enable KFENCE in debug defconfig.

   - Cleanup hugetlbfs s390 specific Kconfig dependency.

   - Quite a lot of trivial fixes to get rid of "W=1" warnings, and and
     other simple cleanups"

* tag 's390-5.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  hugetlbfs: s390 is always 64bit
  s390/ftrace: remove incorrect __va usage
  s390/zcrypt: remove incorrect kernel doc indicators
  scsi: zfcp: fix kernel doc comments
  s390/sclp: add __nonstring annotation
  s390/hmcdrv_ftp: fix kernel doc comment
  s390: remove xpram device driver
  s390/pci: read clp_list_pci_req only once
  s390/pci: fix clp_get_state() handling of -ENODEV
  s390/cio: fix kernel doc comment
  s390/ctrlchar: fix kernel doc comment
  s390/con3270: use proper type for tasklet function
  s390/cpum_cf: move array from header to C file
  s390/mm: fix kernel doc comments
  s390/topology: fix topology information when calling cpu hotplug notifiers
  s390/unwind: use current_frame_address() to unwind current task
  s390/configs: enable CONFIG_KFENCE in debug_defconfig
  s390/entry: make oklabel within CHKSTG macro local
  s390: add kmemleak annotation in stack_alloc()
  s390/cio: dont unregister subchannel from child-drivers
2021-09-09 12:55:12 -07:00
Heiko Carstens
f6beebb15e scsi: zfcp: fix kernel doc comments
A couple of function names don't match what the kernel doc comments
indicate.

Acked-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-09-08 14:23:31 +02:00
Bart Van Assche
d78f31ce7e scsi: zfcp: Use scsi_cmd_to_rq() instead of scsi_cmnd.request
Prepare for removal of the request pointer by using scsi_cmd_to_rq()
instead. This patch does not change any functionality.

Link: https://lore.kernel.org/r/20210809230355.8186-11-bvanassche@acm.org
Acked-by: Benjamin Block <bblock@linux.ibm.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-08-11 22:25:37 -04:00
Martin K. Petersen
73e61d5c22 scsi: zfcp: Use the proper SCSI midlayer interfaces for PI
Use scsi_prot_ref_tag() and scsi_prot_interval() instead scsi_get_lba() and
sector_size.

Link: https://lore.kernel.org/r/20210609033929.3815-7-martin.petersen@oracle.com
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Message-Id: <20210609033929.3815-7-martin.petersen@oracle.com>
2021-07-20 22:10:42 -04:00
Julian Wiedmann
91cf21ec6d scsi: zfcp: Remove unneeded INIT_LIST_HEAD() for FSF requests
INIT_LIST_HEAD() is only needed for actual list heads, while req->list is
used as a list entry.

Note that when the error path in zfcp_fsf_req_send() removes the request
from the adapter's list of pending requests, it actually looks up the
request from the zfcp_reqlist - rather than just calling list_del().  So
there's no risk of us calling list_del() on a request that hasn't been
added to any list yet.

Link: https://lore.kernel.org/r/254dc0ae28dccc43ab0b1079ef2c8dcb5fe1d2e4.1618417667.git.bblock@linux.ibm.com
Reviewed-by: Benjamin Block <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>
2021-04-15 22:19:39 -04:00
Linus Torvalds
60f7c503d9 SCSI misc on 20201216
This series consists of the usual driver updates (ufs, qla2xxx,
 smartpqi, target, zfcp, fnic, mpt3sas, ibmvfc) plus a load of
 cleanups, a major power management rework and a load of assorted minor
 updates.  There are a few core updates (formatting fixes being the big
 one) but nothing major this cycle.
 
 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, smartpqi,
  target, zfcp, fnic, mpt3sas, ibmvfc) plus a load of cleanups, a major
  power management rework and a load of assorted minor updates.

  There are a few core updates (formatting fixes being the big one) but
  nothing major this cycle"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (279 commits)
  scsi: mpt3sas: Update driver version to 36.100.00.00
  scsi: mpt3sas: Handle trigger page after firmware update
  scsi: mpt3sas: Add persistent MPI trigger page
  scsi: mpt3sas: Add persistent SCSI sense trigger page
  scsi: mpt3sas: Add persistent Event trigger page
  scsi: mpt3sas: Add persistent Master trigger page
  scsi: mpt3sas: Add persistent trigger pages support
  scsi: mpt3sas: Sync time periodically between driver and firmware
  scsi: qla2xxx: Update version to 10.02.00.104-k
  scsi: qla2xxx: Fix device loss on 4G and older HBAs
  scsi: qla2xxx: If fcport is undergoing deletion complete I/O with retry
  scsi: qla2xxx: Fix the call trace for flush workqueue
  scsi: qla2xxx: Fix flash update in 28XX adapters on big endian machines
  scsi: qla2xxx: Handle aborts correctly for port undergoing deletion
  scsi: qla2xxx: Fix N2N and NVMe connect retry failure
  scsi: qla2xxx: Fix FW initialization error on big endian machines
  scsi: qla2xxx: Fix crash during driver load on big endian machines
  scsi: qla2xxx: Fix compilation issue in PPC systems
  scsi: qla2xxx: Don't check for fw_started while posting NVMe command
  scsi: qla2xxx: Tear down session if FW say it is down
  ...
2020-12-16 13:34:31 -08:00
Christoph Hellwig
a54895fa05 block: remove the request_queue to argument request based tracepoints
The request_queue can trivially be derived from the request.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-04 09:42:00 -07:00
Julian Wiedmann
d901963174 scsi: zfcp: Handle event-lost notification for Version Change events
As recovery for a lost Version Change event, trigger an Exchange Config
Data cmd to retrieve the current FW version.

Doing so requires process context (as eg. zfcp_qdio_sbal_get() might need
to sleep), so defer from tasklet context into a work item.

Link: https://lore.kernel.org/r/297c7be2944c3714863fcd22d531d910312d29f0.1603908167.git.bblock@linux.ibm.com
Suggested-by: Steffen Maier <maier@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>
2020-10-29 22:17:01 -04:00
Julian Wiedmann
a6c37abe69 scsi: zfcp: Process Version Change events
Handle notifications for a concurrent change of the FCP Channel firmware.
Update the relevant user-visible fields to provide accurate data.

Link: https://lore.kernel.org/r/d2c7bc57c6cf1b65eabbf7a5d0e3927b9f65647f.1603908167.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>
2020-10-29 22:17:01 -04:00
Julian Wiedmann
d251193d17 scsi: zfcp: Clarify access to erp_action in zfcp_fsf_req_complete()
While reviewing commit 936e6b85da ("scsi: zfcp: Fix panic on ERP timeout
for previously dismissed ERP action"), I stumbled over
zfcp_fsf_req_complete() and wondered whether it has similar issues wrt
concurrent modification of req->erp_action by
zfcp_erp_strategy_check_fsfreq().

But a closer look shows that both its two callers [zfcp_fsf_reqid_check(),
zfcp_fsf_req_dismiss_all()] remove the request from the adapter's req_list
under the req_list's lock.  Hence we can trust that if
zfcp_erp_strategy_check_fsfreq() concurrently looks up the corresponding
req_id, it won't find this request and is thus unable to modify it while
it's being processed by zfcp_fsf_req_complete().

Add a code comment that hopefully makes this easier for future readers, and
condense the two accesses to ->erp_action that made me trip over this code
path in the first place.

Link: https://lore.kernel.org/r/c500eac301fcbba5af942bbd200f2d6b14e46994.1599765652.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 18:01:58 -04:00
Steffen Maier
2d9a2c5f58 scsi: zfcp: Fix use-after-free in request timeout handlers
Before v4.15 commit 75492a5156 ("s390/scsi: Convert timers to use
timer_setup()"), we intentionally only passed zfcp_adapter as context
argument to zfcp_fsf_request_timeout_handler(). Since we only trigger
adapter recovery, it was unnecessary to sync against races between timeout
and (late) completion.  Likewise, we only passed zfcp_erp_action as context
argument to zfcp_erp_timeout_handler(). Since we only wakeup an ERP action,
it was unnecessary to sync against races between timeout and (late)
completion.

Meanwhile the timeout handlers get timer_list as context argument and do a
timer-specific container-of to zfcp_fsf_req which can have been freed.

Fix it by making sure that any request timeout handlers, that might just
have started before del_timer(), are completed by using del_timer_sync()
instead. This ensures the request free happens afterwards.

Space time diagram of potential use-after-free:

Basic idea is to have 2 or more pending requests whose timeouts run out at
almost the same time.

req 1 timeout     ERP thread        req 2 timeout
----------------  ----------------  ---------------------------------------
zfcp_fsf_request_timeout_handler
fsf_req = from_timer(fsf_req, t, timer)
adapter = fsf_req->adapter
zfcp_qdio_siosl(adapter)
zfcp_erp_adapter_reopen(adapter,...)
                  zfcp_erp_strategy
                  ...
                  zfcp_fsf_req_dismiss_all
                  list_for_each_entry_safe
                    zfcp_fsf_req_complete 1
                    del_timer 1
                    zfcp_fsf_req_free 1
                    zfcp_fsf_req_complete 2
                                    zfcp_fsf_request_timeout_handler
                    del_timer 2
                                    fsf_req = from_timer(fsf_req, t, timer)
                    zfcp_fsf_req_free 2
                                    adapter = fsf_req->adapter
                                              ^^^^^^^ already freed

Link: https://lore.kernel.org/r/20200813152856.50088-1-maier@linux.ibm.com
Fixes: 75492a5156 ("s390/scsi: Convert timers to use timer_setup()")
Cc: <stable@vger.kernel.org> #4.15+
Suggested-by: Julian Wiedmann <jwi@linux.ibm.com>
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>
2020-08-17 22:12:09 -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
990486f3a8 scsi: zfcp: Fence fc_host updates during link-down handling
When receiving a notification that a FCP device lost its local link we
usually update the fibre channel host object which represents that FCP
device to reflect that.

This notification/information can also surface when the FCP device is
running through adapter recovery (exchange config and exchange port data
return incomplete).

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, and this happens during the very first
adapter recovery, these updates can not be done until after the scsi host
object is allocated.

Reorder the fc_host updates in zfcp_fsf_fc_host_link_down() so that they
only happen after a check of whether the scsi host object is already
allocated or not.

During the first adapter recovery this will cause the skip of these updates
if a link-down condition is detected, but we can repeat them after we
allocated the scsi host object, if necessary.

For any further link-down handling the only changes in the work flow are
the slightly reordered assignments in zfcp_fsf_fc_host_link_down().

Link: https://lore.kernel.org/r/f841f2cda61dcd7b8549910c44e1831927459edf.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 23:19:48 -04:00
Benjamin Block
52e61fde5e scsi: zfcp: Move fc_host updates during xport data handling into fenced function
When executing exchange port data for a FCP device for the first time, or
after an adapter recovery, we update several properties of the fibre
channel host object which represents that FCP device.

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

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

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

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

Link: https://lore.kernel.org/r/ae454c2dc6da0b02907c489af91d0b211d331825.1588956679.git.bblock@linux.ibm.com
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-05-11 23:19:48 -04:00
Benjamin Block
bd1684817d scsi: zfcp: Move shost updates during xconfig data handling into fenced function
When executing exchange config data for a FCP device for the first time, or
after an adapter recovery, we update several properties of the scsi host or
fibre channel host object that represent that FCP device.

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

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

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

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

Link: https://lore.kernel.org/r/5fc3f4d38d4334f7aa595497c6f7865fb1102e0f.1588956679.git.bblock@linux.ibm.com
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-05-11 23:19:47 -04:00
Linus Torvalds
93f3321f65 SCSI misc on 20200410
This is a batch of changes that didn't make it in the initial pull
 request because the lpfc series had to be rebased to redo an incorrect
 split.  It's basically driver updates to lpfc, target, bnx2fc and ufs
 with the rest being minor updates except the sr_block_release one
 which fixes a use after free introduced by the removal of the global
 mutex in the first patch set.
 
 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 more SCSI updates from James Bottomley:
 "This is a batch of changes that didn't make it in the initial pull
  request because the lpfc series had to be rebased to redo an incorrect
  split.

  It's basically driver updates to lpfc, target, bnx2fc and ufs with the
  rest being minor updates except the sr_block_release one which fixes a
  use after free introduced by the removal of the global mutex in the
  first patch set"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (35 commits)
  scsi: core: Add DID_ALLOC_FAILURE and DID_MEDIUM_ERROR to hostbyte_table
  scsi: ufs: Use ufshcd_config_pwr_mode() when scaling gear
  scsi: bnx2fc: fix boolreturn.cocci warnings
  scsi: zfcp: use fallthrough;
  scsi: aacraid: do not overwrite retval in aac_reset_adapter()
  scsi: sr: Fix sr_block_release()
  scsi: aic7xxx: Remove more FreeBSD-specific code
  scsi: mpt3sas: Fix kernel panic observed on soft HBA unplug
  scsi: ufs: set device as active power mode after resetting device
  scsi: iscsi: Report unbind session event when the target has been removed
  scsi: lpfc: Change default SCSI LUN QD to 64
  scsi: libfc: rport state move to PLOGI if all PRLI retry exhausted
  scsi: libfc: If PRLI rejected, move rport to PLOGI state
  scsi: bnx2fc: Update the driver version to 2.12.13
  scsi: bnx2fc: Fix SCSI command completion after cleanup is posted
  scsi: bnx2fc: Process the RQE with CQE in interrupt context
  scsi: target: use the stack for XCOPY passthrough cmds
  scsi: target: increase XCOPY I/O size
  scsi: target: avoid per-loop XCOPY buffer allocations
  scsi: target: drop xcopy DISK BLOCK LENGTH debug
  ...
2020-04-10 12:21:11 -07:00
Linus Torvalds
79f51b7b9c SCSI misc on 20200402
update changing all our txt files to rst ones.  Excluding that, we
 have the usual driver updates (qla2xxx, ufs, lpfc, zfcp, ibmvfc,
 pm80xx, aacraid), a treewide update for scnprintf and some other minor
 updates.  The major core update is Hannes moving functions out of the
 aacraid driver and into the core.
 
 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 series has a huge amount of churn because it pulls in Mauro's doc
  update changing all our txt files to rst ones.

  Excluding that, we have the usual driver updates (qla2xxx, ufs, lpfc,
  zfcp, ibmvfc, pm80xx, aacraid), a treewide update for scnprintf and
  some other minor updates.

  The major core change is Hannes moving functions out of the aacraid
  driver and into the core"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (223 commits)
  scsi: aic7xxx: aic97xx: Remove FreeBSD-specific code
  scsi: ufs: Do not rely on prefetched data
  scsi: dc395x: remove dc395x_bios_param
  scsi: libiscsi: Fix error count for active session
  scsi: hpsa: correct race condition in offload enabled
  scsi: message: fusion: Replace zero-length array with flexible-array member
  scsi: qedi: Add PCI shutdown handler support
  scsi: qedi: Add MFW error recovery process
  scsi: ufs: Enable block layer runtime PM for well-known logical units
  scsi: ufs-qcom: Override devfreq parameters
  scsi: ufshcd: Let vendor override devfreq parameters
  scsi: ufshcd: Update the set frequency to devfreq
  scsi: ufs: Resume ufs host before accessing ufs device
  scsi: ufs-mediatek: customize the delay for enabling host
  scsi: ufs: make HCE polling more compact to improve initialization latency
  scsi: ufs: allow custom delay prior to host enabling
  scsi: ufs-mediatek: use common delay function
  scsi: ufs: introduce common and flexible delay function
  scsi: ufs: use an enum for host capabilities
  scsi: ufs: fix uninitialized tx_lanes in ufshcd_disable_tx_lcc()
  ...
2020-04-02 17:03:53 -07:00
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
Jens Remus
42cabdaf10 scsi: zfcp: log FC Endpoint Security errors
Log any FC Endpoint Security errors to the kernel ring buffer with rate-
limiting.

Link: https://lore.kernel.org/r/20200312174505.51294-11-maier@linux.ibm.com
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-03-17 13:12:42 -04:00
Jens Remus
e53d92856e scsi: zfcp: enhance handling of FC Endpoint Security errors
Enable for explicit FCP channel FC Endpoint Security error reporting and
handle any FSF security errors according to specification. Take the
following recovery actions when a FSF_SECURITY_ERROR is reported for the
specified FSF commands:

- Open Port: Retry the command if possible
- Send FCP : Physically close the remote port and reopen

For Open Port the command status is set to error, which triggers a retry.
For Send FCP the command status is set to error and recovery is triggered
to physically reopen the remote port.

Link: https://lore.kernel.org/r/20200312174505.51294-10-maier@linux.ibm.com
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-03-17 13:12:41 -04:00
Jens Remus
616da39e00 scsi: zfcp: trace FC Endpoint Security of FCP devices and connections
Trace changes in Fibre Channel Endpoint Security capabilities of FCP
devices as well as changes in Fibre Channel Endpoint Security state of
their connections to FC remote ports as FC Endpoint Security changes with
trace level 3 in HBA DBF.

A change in FC Endpoint Security capabilities of FCP devices is traced as
response to FSF command FSF_QTCB_EXCHANGE_PORT_DATA with a trace tag of
"fsfcesa" and a WWPN of ZFCP_DBF_INVALID_WWPN = 0x0000000000000000 (see
FC-FS-4 §18 "Name_Identifier Formats", NAA field).

A change in FC Endpoint Security state of connections between FCP devices
and FC remote ports is traced as response to FSF command
FSF_QTCB_OPEN_PORT_WITH_DID with a trace tag of "fsfcesp".

Example trace record of FC Endpoint Security capability change of FCP
device formatted with zfcpdbf from s390-tools:

Timestamp      : ...
Area           : HBA
Subarea        : 00
Level          : 3
Exception      : -
CPU ID         : ...
Caller         : 0x...
Record ID      : 5                    ZFCP_DBF_HBA_FCES
Tag            : fsfcesa              FSF FC Endpoint Security adapter
Request ID     : 0x...
Request status : 0x00000010
FSF cmnd       : 0x0000000e           FSF_QTCB_EXCHANGE_PORT_DATA
FSF sequence no: 0x...
FSF issued     : ...
FSF stat       : 0x00000000           FSF_GOOD
FSF stat qual  : n/a
Prot stat      : n/a
Prot stat qual : n/a
Port handle    : 0x00000000           none (invalid)
LUN handle     : n/a
WWPN           : 0x0000000000000000   ZFCP_DBF_INVALID_WWPN
FCES old       : 0x00000000           old FC Endpoint Security
FCES new       : 0x00000007           new FC Endpoint Security

Example trace record of FC Endpoint Security change of connection to
FC remote port formatted with zfcpdbf from s390-tools:

Timestamp      : ...
Area           : HBA
Subarea        : 00
Level          : 3
Exception      : -
CPU ID         : ...
Caller         : 0x...
Record ID      : 5                    ZFCP_DBF_HBA_FCES
Tag            : fsfcesp              FSF FC Endpoint Security port
Request ID     : 0x...
Request status : 0x00000010
FSF cmnd       : 0x00000005           FSF_QTCB_OPEN_PORT_WITH_DID
FSF sequence no: 0x...
FSF issued     : ...
FSF stat       : 0x00000000           FSF_GOOD
FSF stat qual  : n/a
Prot stat      : n/a
Prot stat qual : n/a
Port handle    : 0x...
WWPN           : 0x500507630401120c   WWPN
FCES old       : 0x00000000           old FC Endpoint Security
FCES new       : 0x00000004           new FC Endpoint Security

Link: https://lore.kernel.org/r/20200312174505.51294-9-maier@linux.ibm.com
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-03-17 13:12:40 -04:00
Jens Remus
f0d26ae847 scsi: zfcp: log FC Endpoint Security of connections
Log the usage of and subsequent changes in FC Endpoint Security of
connections between FCP devices and FC remote ports to the kernel ring
buffer. Activation of FC Endpoint Security is logged as informational.
Change and deactivation are logged as warning.

No logging takes place, if FC Endpoint Security is not used (i.e. never
activated) on a connection or if it does not change during reopen of a port
(e.g. due to adapter or port recovery).

Link: https://lore.kernel.org/r/20200312174505.51294-8-maier@linux.ibm.com
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Fedor Loshakov <loshakov@linux.ibm.com>
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-03-17 13:12:39 -04:00
Jens Remus
a17c784600 scsi: zfcp: report FC Endpoint Security in sysfs
Add an interface to read Fibre Channel Endpoint Security information of FCP
channels and their connections to FC remote ports. It comes in the form of
new sysfs attributes that are attached to the CCW device representing the
FCP device and its zfcp port objects.

The read-only sysfs attribute "fc_security" of a CCW device representing a
FCP device shows the FC Endpoint Security capabilities of the device.
Possible values are: "unknown", "unsupported", "none", or a comma-
separated list of one or more mnemonics and/or one hexadecimal value
representing the supported FC Endpoint Security:

  Authentication: Authentication supported
  Encryption    : Encryption supported

The read-only sysfs attribute "fc_security" of a zfcp port object shows the
FC Endpoint Security used on the connection between its parent FCP device
and the FC remote port. Possible values are: "unknown", "unsupported",
"none", or a mnemonic or hexadecimal value representing the FC Endpoint
Security used:

  Authentication: Connection has been authenticated
  Encryption    : Connection is encrypted

Both sysfs attributes may return hexadecimal values instead of mnemonics,
if the mnemonic lookup table does not contain an entry for the FC Endpoint
Security reported by the FCP device.

Link: https://lore.kernel.org/r/20200312174505.51294-7-maier@linux.ibm.com
Reviewed-by: Fedor Loshakov <loshakov@linux.ibm.com>
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-03-17 13:12:38 -04:00
Jens Remus
185f2d2d59 scsi: zfcp: auto variables for dereferenced structs in open port handler
Introduce automatic variables for adapter and QTCB bottom in
zfcp_fsf_open_port_handler(). This facilitates subsequent changes to meet
the 80 character per line limit.

Link: https://lore.kernel.org/r/20200312174505.51294-6-maier@linux.ibm.com
Reviewed-by: Fedor Loshakov <loshakov@linux.ibm.com>
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-03-17 13:12:36 -04:00
Steffen Maier
7e0e4e0958 scsi: zfcp: fix fc_host attributes that should be unknown on local link down
When we get an unsolicited notification on local link went down,
zfcp_fsf_status_read_link_down() calls zfcp_fsf_link_down_info_eval().
This only blocks rports, and sets ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED and
ZFCP_STATUS_COMMON_ERP_FAILED. Only the fc_host port_state changes to
"Linkdown", because zfcp_scsi_get_host_port_state() is an active callback
and uses the adapter status.

Other fc_host attributes model, port_id, port_type, speed, fabric_name (and
zfcp device attributes card_version, peer_wwpn, peer_wwnn, peer_d_id) which
depend on a local link, continued to show their last known "good" value.

Only if something triggered an exchange config data, some values were
updated to their unknown equivalent via case
FSF_EXCHANGE_CONFIG_DATA_INCOMPLETE due to local link down.  Triggers for
exchange config data are adapter recovery, or reading any of the following
zfcp-specific scsi host sysfs attributes "requests", "megabytes", or
"seconds_active" in /sys/devices/css*/*.*.*/*.*.*/host*/scsi_host/host*/.

The other fc_host attributes active_fc4s and permanent_port_name continued
to show their last known "good" value.  Only if something triggered an
exchange port data, some values changed.  Active_fc4s became all zeros as
unknown equivalent during link down.  Permanent_port_name does not depend
on a local link. But for non-NPIV FCP devices, permanent_port_name
erroneously became whatever value fc_host port_name had at that point in
time (see previous paragraph).  Triggers for exchange port data are the
zfcp-specific scsi host sysfs attribute "utilization", or
[{reset,get}_fc_host_stats] write anything into "reset_statistics" or read
any of the other attributes under
/sys/devices/css*/*.*.*/*.*.*/host*/fc_host/host*/statistics/.

(cf. v4.9 commit bd77befa5b ("zfcp: fix fc_host port_type with NPIV"))

This is particularly confusing when using "lszfcp -b <fcpdevbusid> -Ha" or
dbginfo.sh which read fc_host attributes and also scsi_host attributes.
After link down, the first invocation produces (abbreviated):

Class = "fc_host"
    active_fc4s         = "0x00 0x00 0x01 0x00 ..."
    ...
    fabric_name         = "0x10000027f8e04c49"
    ...
    permanent_port_name = "0xc05076e4588059c1"
    port_id             = "0x244800"
    port_state          = "Linkdown"
    port_type           = "NPort (fabric via point-to-point)"
    ...
    speed               = "16 Gbit"
Class = "scsi_host"
    ...
    megabytes           = "0 0"
    ...
    requests            = "0 0 0"
    seconds_active      = "37"
    ...
    utilization         = "0 0 0"

The second and next invocations produce (abbreviated):

Class = "fc_host"
    active_fc4s         = "0x00 0x00 0x00 0x00 ..."
    ...
    fabric_name         = "0x0"
    ...
    permanent_port_name = "0x0"
    port_id             = "0x000000"
    port_state          = "Linkdown"
    port_type           = "Unknown"
    ...
    speed               = "unknown"
Class = "scsi_host"
    ...
    megabytes           = "0 0"
    ...
    requests            = "0 0 0"
    seconds_active      = "38"
    ...
    utilization         = "0 0 0"

Factor out the resetting of local link dependent fc_host attributes from
zfcp_fsf_exchange_config_data_handler() case
FSF_EXCHANGE_CONFIG_DATA_INCOMPLETE into a new helper function
zfcp_fsf_fc_host_link_down().  All code places that detect local link down
(SRB, FSF_PROT_LINK_DOWN, xconf data/port incomplete) call
zfcp_fsf_link_down_info_eval().  Call the new helper from there. This works
because zfcp_fsf_link_down_info_eval() and thus the helper is called before
zfcp_fsf_exchange_{config,port}_evaluate().

Port_name and node_name are always valid, so never reset them.

Get the permanent_port_name from exchange port data unconditionally as it
always has a valid known good value, even during link down.

Note: Rather than hardcode in zfcp_fsf_exchange_config_evaluate(), fc_host
supported_classes could theoretically get its value from
fsf_qtcb_bottom_port.class_of_service in zfcp_fsf_exchange_port_evaluate().

When the link comes back, we get a different notification, perform adapter
recovery, and this triggers an implicit exchange config data followed by
exchange port data filling in the link dependent fc_host attributes with
known good values again.

Link: https://lore.kernel.org/r/20200312174505.51294-5-maier@linux.ibm.com
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-03-17 13:12:36 -04:00
Steffen Maier
538c6e910b scsi: zfcp: wire previously driver-specific sysfs attributes also to fc_host
Manufacturer, HBA model, firmware version, and hardware version.  Use the
same value format as for the driver-specific attributes.  Keep the
driver-specific attributes for stable user space sysfs API.

Link: https://lore.kernel.org/r/20200312174505.51294-4-maier@linux.ibm.com
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-03-17 13:12:35 -04:00
Steffen Maier
e05a10a055 scsi: zfcp: expose fabric name as common fc_host sysfs attribute
FICON Express8S or older, as well as card features newer than FICON
Express16S+ have no certain firmware level requirement.

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

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

Otherwise, the read value is not the fabric name.

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

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

Link: https://lore.kernel.org/r/20200312174505.51294-3-maier@linux.ibm.com
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-03-17 13:12:34 -04:00
Julian Wiedmann
2db01da8d2 s390/qdio: fill SBALEs with absolute addresses
sbale->addr holds an absolute address (or for some FCP usage, an opaque
request ID), and should only be used with proper virt/phys translation.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-02-19 17:26:32 +01:00
Benjamin Block
a10a61e807 scsi: zfcp: support retrieval of SFP Data via Exchange Port Data
A new FCP channel feature allows us to read the diagnostics from our local
SFP transceivers. To make use of that add a flag
(FSF_FEATURE_REQUEST_SFP_DATA) to the feature-set we request from the FCP
channel. Whether the channel actually implements this can be determined via
an other new flag (FSF_FEATURE_REPORT_SFP_DATA), that is set in the
adapter_features field of the adapter structure after Exchange Config Data
finished.

Also add the corresponding definitions in the QTCB Bottom for Exchange Port
Data. These new definitions are only valid, if FSF_FEATURE_REPORT_SFP_DATA
is set.

Link: https://lore.kernel.org/r/ee1eba4de71eb06b4d82207ad4f428429346156f.1572018132.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>
2019-10-28 22:16:15 -04:00
Benjamin Block
088210233e scsi: zfcp: add diagnostics buffer for exchange config data
In the same vein as the previous patch, add diagnostic data capture for the
Exchange Config Data command.

Link: https://lore.kernel.org/r/7d8ac0a6cad403fa8f8b888693476a84e80a277b.1572018131.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>
2019-10-28 22:16:14 -04:00
Benjamin Block
7e418833e6 scsi: zfcp: diagnostics buffer caching and use for exchange port data
The FCP channel exposes two central interfaces to receive information about
the local FCP-Adapter/-Port: Exchange Port and Exchange Config Data. Using
these commands can negatively impact the adapter if we allow them to be
sent at a very high rate.

The later parts of this patchset will introduce new user-interfaces to
receive more diagnostics from the adapter. To prevent any negative impact
from using those, this patch adds a simple caching-mechanism that will
prevent a malicious/faulty userspace-application from generating an
abnormal high amount of Exchange Port/Config Data traffic.

Relevant diagnostic data that is received via Exchange Config/Port Data is
cached in buffers associated with the corresponding adapter-struct.  Each
buffer is associated with a timestamp that signals how old the data is,
and, added via a following patch in this series, lets userspace-interfaces
determine when the data is too old and needs to be updated.

Buffer-updates are made during the normal response path of the
corresponding command. With this patch only the output of the Exchange Port
Data command is captured.

Link: https://lore.kernel.org/r/054ca020ce0a53dc0d9176428bea373898944e6a.1572018130.git.bblock@linux.ibm.com
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2019-10-28 22:16:14 -04:00
Benjamin Block
92953c6e0a scsi: zfcp: signal incomplete or error for sync exchange config/port data
Adds a new FSF-Request status flag (ZFCP_STATUS_FSFREQ_XDATAINCOMPLETE)
that signal that the data received using Exchange Config Data or Exchange
Port Data was incomplete. This new flags is set in the respective handlers
during the response path.

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

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

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

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

Link: https://lore.kernel.org/r/e14f0702fa2b00a4d1f37c7981a13f2dd1ea2c83.1572018130.git.bblock@linux.ibm.com
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2019-10-28 22:16:14 -04:00
Steffen Maier
2190168aae scsi: zfcp: fix reaction on bit error threshold notification
On excessive bit errors for the FCP channel ingress fibre path, the channel
notifies us.  Previously, we only emitted a kernel message and a trace
record.  Since performance can become suboptimal with I/O timeouts due to
bit errors, we now stop using an FCP device by default on channel
notification so multipath on top can timely failover to other paths.  A new
module parameter zfcp.ber_stop can be used to get zfcp old behavior.

User explanation of new kernel message:

 * Description:
 * The FCP channel reported that its bit error threshold has been exceeded.
 * These errors might result from a problem with the physical components
 * of the local fibre link into the FCP channel.
 * The problem might be damage or malfunction of the cable or
 * cable connection between the FCP channel and
 * the adjacent fabric switch port or the point-to-point peer.
 * Find details about the errors in the HBA trace for the FCP device.
 * The zfcp device driver closed down the FCP device
 * to limit the performance impact from possible I/O command timeouts.
 * User action:
 * Check for problems on the local fibre link, ensure that fibre optics are
 * clean and functional, and all cables are properly plugged.
 * After the repair action, you can manually recover the FCP device by
 * writing "0" into its "failed" sysfs attribute.
 * If recovery through sysfs is not possible, set the CHPID of the device
 * offline and back online on the service element.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Cc: <stable@vger.kernel.org> #2.6.30+
Link: https://lore.kernel.org/r/20191001104949.42810-1-maier@linux.ibm.com
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2019-10-03 21:45:53 -04:00
Benjamin Block
106d45f350 scsi: zfcp: fix request object use-after-free in send path causing wrong traces
When tracing instances where we open and close WKA ports, we also pass the
request-ID of the respective FSF command.

But after successfully sending the FSF command we must not use the
request-object anymore, as this might result in an use-after-free (see
"zfcp: fix request object use-after-free in send path causing seqno
errors" ).

To fix this add a new variable that caches the request-ID before sending
the request. This won't change during the hand-off to the FCP channel,
and so it's safe to trace this cached request-ID later, instead of using
the request object.

Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Fixes: d27a7cb919 ("zfcp: trace on request for open and close of WKA port")
Cc: <stable@vger.kernel.org> #2.6.38+
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2019-07-11 21:04:22 -04:00
Benjamin Block
b76becde2b scsi: zfcp: fix request object use-after-free in send path causing seqno errors
With a recent change to our send path for FSF commands we introduced a
possible use-after-free of request-objects, that might further lead to
zfcp crafting bad requests, which the FCP channel correctly complains
about with an error (FSF_PROT_SEQ_NUMB_ERROR). This error is then handled
by an adapter-wide recovery.

The following sequence illustrates the possible use-after-free:

    Send Path:

        int zfcp_fsf_open_port(struct zfcp_erp_action *erp_action)
        {
                struct zfcp_fsf_req *req;
                ...
                spin_lock_irq(&qdio->req_q_lock);
        //                     ^^^^^^^^^^^^^^^^
        //                     protects QDIO queue during sending
                ...
                req = zfcp_fsf_req_create(qdio,
                                          FSF_QTCB_OPEN_PORT_WITH_DID,
                                          SBAL_SFLAGS0_TYPE_READ,
                                          qdio->adapter->pool.erp_req);
        //            ^^^^^^^^^^^^^^^^^^^
        //            allocation of the request-object
                ...
                retval = zfcp_fsf_req_send(req);
                ...
                spin_unlock_irq(&qdio->req_q_lock);
                return retval;
        }

        static int zfcp_fsf_req_send(struct zfcp_fsf_req *req)
        {
                struct zfcp_adapter *adapter = req->adapter;
                struct zfcp_qdio *qdio = adapter->qdio;
                ...
                zfcp_reqlist_add(adapter->req_list, req);
        //      ^^^^^^^^^^^^^^^^
        //      add request to our driver-internal hash-table for tracking
        //      (protected by separate lock req_list->lock)
                ...
                if (zfcp_qdio_send(qdio, &req->qdio_req)) {
        //          ^^^^^^^^^^^^^^
        //          hand-off the request to FCP channel;
        //          the request can complete at any point now
                        ...
                }

                /* Don't increase for unsolicited status */
                if (!zfcp_fsf_req_is_status_read_buffer(req))
        //           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        //           possible use-after-free
                        adapter->fsf_req_seq_no++;
        //                       ^^^^^^^^^^^^^^^^
        //                       because of the use-after-free we might
        //                       miss this accounting, and as follow-up
        //                       this results in the FCP channel error
        //                       FSF_PROT_SEQ_NUMB_ERROR
                adapter->req_no++;

                return 0;
        }

        static inline bool
        zfcp_fsf_req_is_status_read_buffer(struct zfcp_fsf_req *req)
        {
                return req->qtcb == NULL;
        //             ^^^^^^^^^
        //             possible use-after-free
        }

    Response Path:

        void zfcp_fsf_reqid_check(struct zfcp_qdio *qdio, int sbal_idx)
        {
                ...
                struct zfcp_fsf_req *fsf_req;
                ...
                for (idx = 0; idx < QDIO_MAX_ELEMENTS_PER_BUFFER; idx++) {
                        ...
                        fsf_req = zfcp_reqlist_find_rm(adapter->req_list,
                                                       req_id);
        //                        ^^^^^^^^^^^^^^^^^^^^
        //                        remove request from our driver-internal
        //                        hash-table (lock req_list->lock)
                        ...
                        zfcp_fsf_req_complete(fsf_req);
                }
        }

        static void zfcp_fsf_req_complete(struct zfcp_fsf_req *req)
        {
                ...
                if (likely(req->status & ZFCP_STATUS_FSFREQ_CLEANUP))
                        zfcp_fsf_req_free(req);
        //              ^^^^^^^^^^^^^^^^^
        //              free memory for request-object
                else
                        complete(&req->completion);
        //              ^^^^^^^^
        //              completion notification for code-paths that wait
        //              synchronous for the completion of the request; in
        //              those the memory is freed separately
        }

The result of the use-after-free only affects the send path, and can not
lead to any data corruption. In case we miss the sequence-number
accounting, because the memory was already re-purposed, the next FSF
command will fail with said FCP channel error, and we will recover the
whole adapter. This causes no additional errors, but it slows down
traffic.  There is a slight chance of the same thing happen again
recursively after the adapter recovery, but so far this has not been seen.

This was seen under z/VM, where the send path might run on a virtual CPU
that gets scheduled away by z/VM, while the return path might still run,
and so create the necessary timing. Running with KASAN can also slow down
the kernel sufficiently to run into this user-after-free, and then see the
report by KASAN.

To fix this, simply pull the test for the sequence-number accounting in
front of the hand-off to the FCP channel (this information doesn't change
during hand-off), but leave the sequence-number accounting itself where it
is.

To make future regressions of the same kind less likely, add comments to
all closely related code-paths.

Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Fixes: f9eca02276 ("scsi: zfcp: drop duplicate fsf_command from zfcp_fsf_req which is also in QTCB header")
Cc: <stable@vger.kernel.org> #5.0+
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2019-07-11 21:04:22 -04:00
Steffen Maier
8684d61481 scsi: zfcp: silence all W=1 build warnings for existing kdoc
While at it also improve some copy & paste kdoc mistakes.

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-11-15 15:01:18 -05:00
Steffen Maier
e0effe8935 scsi: zfcp: properly format LUN (and WWPN) for LUN sharing violation kmsg
zfcp: <devbusid>: LUN 0x0 on port 0x5005076......... ...
zfcp: <devbusid>: LUN 0x1000000000000 on port 0x5005076......... ...

should be

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

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-11-15 15:01:18 -05:00
Steffen Maier
724e144387 scsi: zfcp: update kernel message for invalid FCP_CMND length, it's not the CDB
The CDB is just a part inside of FCP_CMND, see zfcp_fc_scsi_to_fcp().
While at it, fix the device driver reaction: adapter not LUN shutdown.

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-11-15 15:01:17 -05:00
Steffen Maier
9704154fa0 scsi: zfcp: drop duplicate seq_no from zfcp_fsf_req which is also in QTCB header
There is no point for double bookkeeping especially just for tracing.  The
trace can take it from the QTCB which always exists for non-SRB responses
traced with zfcp_dbf_hba_fsf_res().

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

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

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-11-15 15:01:17 -05:00
Steffen Maier
f9eca02276 scsi: zfcp: drop duplicate fsf_command from zfcp_fsf_req which is also in QTCB header
Status read buffers (SRBs, unsolicited notifications) never use a QTCB
[zfcp_fsf_req_create()]. zfcp_fsf_req_send() already uses this to
distinguish SRBs from other FSF request types. We can re-use this method in
zfcp_fsf_req_complete(). Introduce a helper function to make the check for
req->qtcb less magic.

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

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

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

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

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-11-15 15:01:17 -05:00
Steffen Maier
eb67f93ffa scsi: zfcp: namespace prefix for internal latency data structures
In contrast to struct fsf_qual_latency_info, the ones here are not FSF but
software defined zfcp-internal.

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-11-15 15:01:17 -05:00
Steffen Maier
a0e86d9555 scsi: zfcp: move scsi_eh & non-ERP timeout defines owned by and local to zfcp_fsf.c
Also clarify namespace prefix for the timeout used for FSF requests on
behalf of SCSI error recovery: It is zfcp_fsf_ not zfcp_scsi_.

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-11-15 15:01:17 -05:00
Jens Remus
6e2e490080 scsi: zfcp: add port speed capabilities
Add port speed capabilities as defined in FC-LS RPSC ELS that have a
counterpart FC_PORTSPEED_* defined in scsi/scsi_transport_fc.h.

Suggested-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Fedor Loshakov <loshakov@linux.ibm.com>
Acked-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Acked-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-05-18 11:28:16 -04:00
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
26f5fa9d47 scsi: zfcp: decouple SCSI setup of TMF from scsi_cmnd
Actually change the signature of zfcp_fsf_fcp_task_mgmt().
Since it was prepared in the previous patch, we only need to delete
a local auto variable which is now the intended argument.

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

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-05-18 11:22:11 -04:00
Steffen Maier
39abb11aca scsi: zfcp: decouple FSF request setup of TMF from scsi_cmnd
In zfcp_fsf_fcp_task_mgmt() resolve the still old argument scsi_cmnd into
scsi_device very early and only depend on scsi_device and derived objects in
the function body.

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

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-05-18 11:22:11 -04:00
Steffen Maier
e0116c91c7 scsi: zfcp: split FCP_CMND IU setup between SCSI I/O and TMF again
This reverts commit 2443c8b23a ("[SCSI] zfcp: Merge FCP task management
setup with regular FCP command setup"), because this introduced a
dependency on the unsuitable SCSI command for scsi_eh / TMF.

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