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2022-11-17scsi: zfcp: Fix double free of FSF request when qdio send failsBenjamin Block
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: e60a6d69f1f8 ("[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>
2022-08-30s390: move from strlcpy with unused retval to strscpyWolfram Sang
Follow the advice of the below link and prefer 'strscpy' in this subsystem. Conversion is 1:1 because the return value is not used. Generated by a coccinelle script. Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/ Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Benjamin Block <bblock@linux.ibm.com> Acked-by: Alexandra Winter <wintera@linux.ibm.com> Link: https://lore.kernel.org/r/20220818205948.6360-1-wsa+renesas@sang-engineering.com Link: https://lore.kernel.org/r/20220818210102.7301-1-wsa+renesas@sang-engineering.com [gor@linux.ibm.com: squashed two changes linked above together] Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-08-01scsi: zfcp: Fix missing auto port scan and thus missing target portsSteffen Maier
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 18f87a67e6d6 ("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 828bc1212a68 ("[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: 5ab944f97e09 ("[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>
2022-07-07scsi: zfcp: Drop redundant "the" in the commentsJiang Jian
There is an unexpected word "the" in the comments that needs to be dropped. file: ./drivers/s390/scsi/zfcp_diag.h line: 5 * Definitions for handling diagnostics in the the zfcp device driver. changed to * Definitions for handling diagnostics in the zfcp device driver. Link: https://lore.kernel.org/r/20220621114207.106405-1-jiangjian@cdjrlc.com Link: https://lore.kernel.org/r/4c02fefa19ab46f0f163990bde3ce10bd9c7caf1.1657122360.git.bblock@linux.ibm.com Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Jiang Jian <jiangjian@cdjrlc.com> Signed-off-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2022-07-07scsi: zfcp: Declare zfcp_sdev_attrs as staticJulian Wiedmann
These attributes are now only accessed through the zfcp_sysfs_sdev_attr_group. Link: https://lore.kernel.org/r/0791b9149ebfa39e6b8eab093113cd2527dbf3d3.1657122360.git.bblock@linux.ibm.com Fixes: d8d7cf3f7d07 ("scsi: zfcp: Switch to attribute groups") 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>
2022-01-24scsi: zfcp: Fix failed recovery on gone remote port with non-NPIV FCP devicesSteffen Maier
Suppose we have an environment with a number of non-NPIV FCP devices (virtual HBAs / FCP devices / zfcp "adapter"s) sharing the same physical FCP channel (HBA port) and its I_T nexus. Plus a number of storage target ports zoned to such shared channel. Now one target port logs out of the fabric causing an RSCN. Zfcp reacts with an ADISC ELS and subsequent port recovery depending on the ADISC result. This happens on all such FCP devices (in different Linux images) concurrently as they all receive a copy of this RSCN. In the following we look at one of those FCP devices. Requests other than FSF_QTCB_FCP_CMND can be slow until they get a response. Depending on which requests are affected by slow responses, there are different recovery outcomes. Here we want to fix failed recoveries on port or adapter level by avoiding recovery requests that can be slow. We need the cached N_Port_ID for the remote port "link" test with ADISC. Just before sending the ADISC, we now intentionally forget the old cached N_Port_ID. The idea is that on receiving an RSCN for a port, we have to assume that any cached information about this port is stale. This forces a fresh new GID_PN [FC-GS] nameserver lookup on any subsequent recovery for the same port. Since we typically can still communicate with the nameserver efficiently, we now reach steady state quicker: Either the nameserver still does not know about the port so we stop recovery, or the nameserver already knows the port potentially with a new N_Port_ID and we can successfully and quickly perform open port recovery. For the one case, where ADISC returns successfully, we re-initialize port->d_id because that case does not involve any port recovery. This also solves a problem if the storage WWPN quickly logs into the fabric again but with a different N_Port_ID. Such as on virtual WWPN takeover during target NPIV failover. [https://www.redbooks.ibm.com/abstracts/redp5477.html] In that case the RSCN from the storage FDISC was ignored by zfcp and we could not successfully recover the failover. On some later failback on the storage, we could have been lucky if the virtual WWPN got the same old N_Port_ID from the SAN switch as we still had cached. Then the related RSCN triggered a successful port reopen recovery. However, there is no guarantee to get the same N_Port_ID on NPIV FDISC. Even though NPIV-enabled FCP devices are not affected by this problem, this code change optimizes recovery time for gone remote ports as a side effect. The timely drop of cached N_Port_IDs prevents unnecessary slow open port attempts. While the problem might have been in code before v2.6.32 commit 799b76d09aee ("[SCSI] zfcp: Decouple gid_pn requests from erp") this fix depends on the gid_pn_work introduced with that commit, so we mark it as culprit to satisfy fix dependencies. Note: Point-to-point remote port is already handled separately and gets its N_Port_ID from the cached peer_d_id. So resetting port->d_id in general does not affect PtP. Link: https://lore.kernel.org/r/20220118165803.3667947-1-maier@linux.ibm.com Fixes: 799b76d09aee ("[SCSI] zfcp: Decouple gid_pn requests from erp") Cc: <stable@vger.kernel.org> #2.6.32+ Suggested-by: Benjamin Block <bblock@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>
2021-12-06s390/qdio: split do_QDIO()Julian Wiedmann
The callers know what type of queue they want to work with. Introduce type-specific variants to add buffers on an {Input,Output} queue, so that we can avoid some function parameters and the de-muxing into type-specific hot paths. Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-12-06s390/qdio: split qdio_inspect_queue()Julian Wiedmann
The callers know what type of queue they want to inspect. Introduce type-specific variants to inspect an {Input,Output} queue, so that we can avoid one function parameter and some conditional branches in the hot paths. Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-10-16scsi: zfcp: Switch to attribute groupsBart Van Assche
struct device supports attribute groups directly but does not support struct device_attribute directly. Hence switch to attribute groups. Link: https://lore.kernel.org/r/20211012233558.4066756-7-bvanassche@acm.org Acked-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-10-16scsi: zfcp_scsi: Call scsi_done() directlyBart Van Assche
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>
2021-09-09Merge tag 's390-5.15-2' of ↵Linus Torvalds
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
2021-09-08scsi: zfcp: fix kernel doc commentsHeiko Carstens
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>
2021-09-02Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsiLinus Torvalds
Pull SCSI updates from James Bottomley: "This series consists of the usual driver updates (ufs, qla2xxx, target, smartpqi, lpfc, mpt3sas). The core change causing the most churn was replacing the command request field request with a macro, allowing us to offset map to it and remove the redundant field; the same was also done for the tag field. The most impactful change is the final removal of scsi_ioctl, which has been deprecated for over a decade" * tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (293 commits) scsi: ufs: Fix ufshcd_request_sense_async() for Samsung KLUFG8RHDA-B2D1 scsi: ufs: ufs-exynos: Fix static checker warning scsi: mpt3sas: Use the proper SCSI midlayer interfaces for PI scsi: lpfc: Use the proper SCSI midlayer interfaces for PI scsi: lpfc: Copyright updates for 14.0.0.1 patches scsi: lpfc: Update lpfc version to 14.0.0.1 scsi: lpfc: Add bsg support for retrieving adapter cmf data scsi: lpfc: Add cmf_info sysfs entry scsi: lpfc: Add debugfs support for cm framework buffers scsi: lpfc: Add support for maintaining the cm statistics buffer scsi: lpfc: Add rx monitoring statistics scsi: lpfc: Add support for the CM framework scsi: lpfc: Add cmfsync WQE support scsi: lpfc: Add support for cm enablement buffer scsi: lpfc: Add cm statistics buffer support scsi: lpfc: Add EDC ELS support scsi: lpfc: Expand FPIN and RDF receive logging scsi: lpfc: Add MIB feature enablement support scsi: lpfc: Add SET_HOST_DATA mbox cmd to pass date/time info to firmware scsi: fc: Add EDC ELS definition ...
2021-08-11scsi: zfcp: Use scsi_cmd_to_rq() instead of scsi_cmnd.requestBart Van Assche
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>
2021-07-27s390/qdio: clarify reporting of errors to the driversJulian Wiedmann
Now that all drivers use qdio_inspect_queue() and qdio's internal queue tasklets are gone, the driver-specified queue handlers are only called for async error reporting (eg. for an error condition in the QEBSM code). So take a moment to clean up the Output Queue handlers (they are _always_ called with qdio_error != 0), and clarify which error types can be reported through what interface. As Benjamin already suggested a while ago, we should turn these into distinct enums at some point. Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-07-20scsi: zfcp: Use the proper SCSI midlayer interfaces for PIMartin K. Petersen
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>
2021-07-12scsi: zfcp: Report port fc_security as unknown early during remote cable pullSteffen Maier
On remote cable pull, a zfcp_port keeps its status and only gets ZFCP_STATUS_PORT_LINK_TEST added. Only after an ADISC timeout, we would actually start port recovery and remove ZFCP_STATUS_COMMON_UNBLOCKED which zfcp_sysfs_port_fc_security_show() detected and reported as "unknown" instead of the old and possibly stale zfcp_port->connection_info. Add check for ZFCP_STATUS_PORT_LINK_TEST for timely "unknown" report. Link: https://lore.kernel.org/r/20210702160922.2667874-1-maier@linux.ibm.com Fixes: a17c78460093 ("scsi: zfcp: report FC Endpoint Security in sysfs") Cc: <stable@vger.kernel.org> #5.7+ 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>
2021-05-31scsi: core: Introduce scsi_build_sense()Hannes Reinecke
Introduce scsi_build_sense() as a wrapper around scsi_build_sense_buffer() to format the buffer and set the correct SCSI status. Link: https://lore.kernel.org/r/20210427083046.31620-8-hare@suse.de Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-04-28Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsiLinus Torvalds
Pull SCSI updates from James Bottomley: "This consists of the usual driver updates (ufs, target, tcmu, smartpqi, lpfc, zfcp, qla2xxx, mpt3sas, pm80xx). The major core change is using a sbitmap instead of an atomic for queue tracking" * tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (412 commits) scsi: target: tcm_fc: Fix a kernel-doc header scsi: target: Shorten ALUA error messages scsi: target: Fix two format specifiers scsi: target: Compare explicitly with SAM_STAT_GOOD scsi: sd: Introduce a new local variable in sd_check_events() scsi: dc395x: Open-code status_byte(u8) calls scsi: 53c700: Open-code status_byte(u8) calls scsi: smartpqi: Remove unused functions scsi: qla4xxx: Remove an unused function scsi: myrs: Remove unused functions scsi: myrb: Remove unused functions scsi: mpt3sas: Fix two kernel-doc headers scsi: fcoe: Suppress a compiler warning scsi: libfc: Fix a format specifier scsi: aacraid: Remove an unused function scsi: core: Introduce enum scsi_disposition scsi: core: Modify the scsi_send_eh_cmnd() return value for the SDEV_BLOCK case scsi: core: Rename scsi_softirq_done() into scsi_complete() scsi: core: Remove an incorrect comment scsi: core: Make the scsi_alloc_sgtables() documentation more accurate ...
2021-04-15scsi: zfcp: Lift Request Queue tasklet & timer from qdioJulian Wiedmann
The qdio layer currently provides its own infrastructure to scan for Request Queue completions & to report them to the device driver. This comes with several drawbacks - having an async tasklet & timer construct in qdio introduces additional lifetime complexity, and makes it harder to integrate them with the rest of the device driver. The timeouts are also currently hard-coded, and can't be tweaked without affecting other qdio drivers (ie. qeth). But due to recent enhancements to the qdio layer, zfcp can actually take full control of the Request Queue completion processing. It merely needs to opt-out from the qdio layer mechanisms by setting the scan_threshold to 0, and then use qdio_inspect_queue() to scan for completions. So re-implement the tasklet & timer mechanism in zfcp, while initially copying the scan conditions from qdio's handle_outbound() and qdio_outbound_tasklet(). One minor behavioural change is that zfcp_qdio_send() will unconditionally reduce the timeout to 1 HZ, rather than leaving it at 10 Hz if it was last armed by the tasklet. This just makes things more consistent. Also note that we can drop a lot of the accumulated cruft in qdio_outbound_tasklet(), as zfcp doesn't even use PCI interrupt requests any longer. This also slightly touches the Response Queue processing, as qdio_get_next_buffers() will no longer implicitly scan for Request Queue completions. So complete the migration to qdio_inspect_queue() here as well and make the tasklet_schedule() visible. Link: https://lore.kernel.org/r/018d3ddd029f8d6ac00cf4184880288c637c4fd1.1618417667.git.bblock@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>
2021-04-15scsi: zfcp: Move the position of put_device()Qinglang Miao
Place the put_device() call after device_unregister() in both zfcp_unit_remove() and zfcp_sysfs_port_remove_store() to make it more natural. put_device() ought to be the last time we touch the object in both functions. Add comments after put_device() to make code clearer. Link: https://lore.kernel.org/r/0a568c7733ba0f1dde28b0c663b90270d44dd540.1618417667.git.bblock@linux.ibm.com Suggested-by: Steffen Maier <maier@linux.ibm.com> Suggested-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com> Signed-off-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-04-15scsi: zfcp: Clean up sysfs code for SFP diagnosticsJulian Wiedmann
The error path from zfcp_adapter_enqueue() no longer attempts to remove the diagnostics attributes if they haven't been created yet. So remove the manual 'sysfs_established' guard for this case, and use device_add_groups() to add all adapter-related sysfs attributes in one go. Link: https://lore.kernel.org/r/37a97537f675d643006271f37723c346189b6eec.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>
2021-04-15scsi: zfcp: Fix sysfs roll-back on error in zfcp_adapter_enqueue()Julian Wiedmann
When zfcp_adapter_enqueue() fails to create the zfcp_sysfs_adapter_attrs group, it calls zfcp_adapter_unregister() to tear down the adapter state again. This then unconditionally attempts to remove the zfcp_sysfs_adapter_attrs group, resulting in a "group not found" WARN from sysfs code. Avoid this by copying most of zfcp_adapter_unregister() into the error path, allowing for more fine-granular roll-back. Then skip the sysfs tear-down steps if we haven't progressed this far in the initialization. Link: https://lore.kernel.org/r/790922cc3af075795fff9a4b787e6bda19bdb3be.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>
2021-04-15scsi: zfcp: Fix indentation coding style issueYevhen Viktorov
Code indentation should use tabs where possible. Link: https://lore.kernel.org/r/e8a15a2f3d64e2e76a214647cfd4fe23d370b165.1618417667.git.bblock@linux.ibm.com Signed-off-by: Yevhen Viktorov <yevhen.viktorov@virginmedia.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>
2021-04-15scsi: zfcp: Remove unneeded INIT_LIST_HEAD() for FSF requestsJulian Wiedmann
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>
2021-03-22s390/qdio: let driver manage the QAOBJulian Wiedmann
We are spending way too much effort on qdio-internal bookkeeping for QAOB management & caching, and it's still not robust. Once qdio's TX path has detached the QAOB from a PENDING buffer, we lost all track of it until it shows up in a CQ notification again. So if the device is torn down before that notification arrives, we leak the QAOB. Just have the driver take care of it, and simply pass down a QAOB if they want a TX with async-completion capability. For a buffer in PENDING state that requires the QAOB for final completion, qeth can now also try to recycle the buffer's QAOB rather than unconditionally freeing it. This also eliminates the qdio_outbuf_state array, which was only needed to transfer the aob->user1 tag from the driver to the qdio layer. Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Acked-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-01-22scsi: zfcp: Do not set COMMAND_COMPLETEHannes Reinecke
COMMAND_COMPLETE is defined as '0', and it is a SCSI parallel message to boot. So drop the call to set_msg_byte(). Link: https://lore.kernel.org/r/20210113090500.129644-15-hare@suse.de Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-12-16Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsiLinus Torvalds
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 ...
2020-12-16Merge tag 'for-5.11/block-2020-12-14' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block updates from Jens Axboe: "Another series of killing more code than what is being added, again thanks to Christoph's relentless cleanups and tech debt tackling. This contains: - blk-iocost improvements (Baolin Wang) - part0 iostat fix (Jeffle Xu) - Disable iopoll for split bios (Jeffle Xu) - block tracepoint cleanups (Christoph Hellwig) - Merging of struct block_device and hd_struct (Christoph Hellwig) - Rework/cleanup of how block device sizes are updated (Christoph Hellwig) - Simplification of gendisk lookup and removal of block device aliasing (Christoph Hellwig) - Block device ioctl cleanups (Christoph Hellwig) - Removal of bdget()/blkdev_get() as exported API (Christoph Hellwig) - Disk change rework, avoid ->revalidate_disk() (Christoph Hellwig) - sbitmap improvements (Pavel Begunkov) - Hybrid polling fix (Pavel Begunkov) - bvec iteration improvements (Pavel Begunkov) - Zone revalidation fixes (Damien Le Moal) - blk-throttle limit fix (Yu Kuai) - Various little fixes" * tag 'for-5.11/block-2020-12-14' of git://git.kernel.dk/linux-block: (126 commits) blk-mq: fix msec comment from micro to milli seconds blk-mq: update arg in comment of blk_mq_map_queue blk-mq: add helper allocating tagset->tags Revert "block: Fix a lockdep complaint triggered by request queue flushing" nvme-loop: use blk_mq_hctx_set_fq_lock_class to set loop's lock class blk-mq: add new API of blk_mq_hctx_set_fq_lock_class block: disable iopoll for split bio block: Improve blk_revalidate_disk_zones() checks sbitmap: simplify wrap check sbitmap: replace CAS with atomic and sbitmap: remove swap_lock sbitmap: optimise sbitmap_deferred_clear() blk-mq: skip hybrid polling if iopoll doesn't spin blk-iocost: Factor out the base vrate change into a separate function blk-iocost: Factor out the active iocgs' state check into a separate function blk-iocost: Move the usage ratio calculation to the correct place blk-iocost: Remove unnecessary advance declaration blk-iocost: Fix some typos in comments blktrace: fix up a kerneldoc comment block: remove the request_queue to argument request based tracepoints ...
2020-12-04block: remove the request_queue to argument request based tracepointsChristoph Hellwig
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>
2020-12-02s390/zfcp: remove pm support from zfcp driverVineeth Vijayan
As part of removing the power management support from s390 arch, remove PM callbacks from the scsi/zfcp driver. Signed-off-by: Vineeth Vijayan <vneethv@linux.ibm.com> Reviewed-by: Steffen Maier <maier@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-10-29scsi: zfcp: Handle event-lost notification for Version Change eventsJulian Wiedmann
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>
2020-10-29scsi: zfcp: Process Version Change eventsJulian Wiedmann
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>
2020-10-29scsi: zfcp: Clarify & assert the stat_lock locking in zfcp_qdio_send()Julian Wiedmann
Explain why the plain spin_lock() suffices in current code, even when the stat_lock is also used by zfcp_qdio_int_req() in tasklet context. We could also promote the spin_lock() to a spin_lock_irqsave(), but that would just obfuscate the locking even further. Link: https://lore.kernel.org/r/b023b1472630f4bf9fce580577d7bb49de89ccbf.1603908167.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>
2020-10-29scsi: zfcp: Remove orphaned function declarationsVasily Gorbik
drivers/s390/scsi/zfcp_ext.h: zfcp_sg_free_table - only declaration left after commit 58f3ead54752 ("scsi: zfcp: move SG table helper from aux to fc and make them static") drivers/s390/scsi/zfcp_ext.h: zfcp_sg_setup_table - only declaration left after commit 58f3ead54752 ("scsi: zfcp: move SG table helper from aux to fc and make them static") Link: https://lore.kernel.org/r/6854ae03c5c65805f746774eeb0f2869fcd6c397.1603908167.git.bblock@linux.ibm.com Reviewed-by: Steffen Maier <maier@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-10-29scsi: zfcp: Lift Input Queue tasklet from qdioJulian Wiedmann
Shift the IRQ tasklet processing from the qdio layer into zfcp. This will allow for a good amount of cleanups in qdio, and provides future opportunity to improve the IRQ processing inside zfcp. We continue to use the qdio layer's internal tasklet/timer mechanism (ie. scan_threshold etc) to check for Request Queue completions. Initially we planned to check for such completions after inspecting the Response Queue - this should typically work, but there's a theoretical race where the device only presents the Request Queue completions _after_ all Response Queue processing has finished. If the Request Queue is then also _completely_ full, we could send no further IOs and thus get no interrupt that would trigger an inspection of the Request Queue. So for now stick to the old model, where we can trust that such a race would be recovered by qdio's internal timer. Code-flow wise, this establishes two levels of control: 1. The qdio layer will only deliver IRQs to the device driver if the QDIO_IRQ_DISABLED flag is cleared. zfcp manages this through qdio_start_irq() / qdio_stop_irq(). The initial state is DISABLED, and zfcp_qdio_open() schedules zfcp's IRQ tasklet once during startup to explicitly enable IRQ delivery. 2. The zfcp tasklet is initialized with tasklet_disable(), and only gets enabled once we open the qdio device. When closing the qdio device, we must disable the tasklet _before_ disabling IRQ delivery (otherwise a concurrently running tasklet could re-enable IRQ delivery after we disabled it). A final tasklet_kill() during teardown ensures that no lingering tasklet_schedule() is still accessing the tasklet structure. Link: https://lore.kernel.org/r/94a765211c48b74a7b91c5e60b158de01db98d43.1603908167.git.bblock@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>
2020-10-16Merge tag 's390-5.10-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Vasily Gorbik: - Remove address space overrides using set_fs() - Convert to generic vDSO - Convert to generic page table dumper - Add ARCH_HAS_DEBUG_WX support - Add leap seconds handling support - Add NVMe firmware-assisted kernel dump support - Extend NVMe boot support with memory clearing control and addition of kernel parameters - AP bus and zcrypt api code rework. Add adapter configure/deconfigure interface. Extend debug features. Add failure injection support - Add ECC secure private keys support - Add KASan support for running protected virtualization host with 4-level paging - Utilize destroy page ultravisor call to speed up secure guests shutdown - Implement ioremap_wc() and ioremap_prot() with MIO in PCI code - Various checksum improvements - Other small various fixes and improvements all over the code * tag 's390-5.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (85 commits) s390/uaccess: fix indentation s390/uaccess: add default cases for __put_user_fn()/__get_user_fn() s390/zcrypt: fix wrong format specifications s390/kprobes: move insn_page to text segment s390/sie: fix typo in SIGP code description s390/lib: fix kernel doc for memcmp() s390/zcrypt: Introduce Failure Injection feature s390/zcrypt: move ap_msg param one level up the call chain s390/ap/zcrypt: revisit ap and zcrypt error handling s390/ap: Support AP card SCLP config and deconfig operations s390/sclp: Add support for SCLP AP adapter config/deconfig s390/ap: add card/queue deconfig state s390/ap: add error response code field for ap queue devices s390/ap: split ap queue state machine state from device state s390/zcrypt: New config switch CONFIG_ZCRYPT_DEBUG s390/zcrypt: introduce msg tracking in zcrypt functions s390/startup: correct early pgm check info formatting s390: remove orphaned extern variables declarations s390/kasan: make sure int handler always run with DAT on s390/ipl: add support to control memory clearing for nvme re-IPL ...
2020-09-15scsi: zfcp: Clarify access to erp_action in zfcp_fsf_req_complete()Julian Wiedmann
While reviewing commit 936e6b85da04 ("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>
2020-09-15scsi: zfcp: Use list_first_entry_or_null() in zfcp_erp_thread()Julian Wiedmann
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>
2020-09-14s390/qdio: always use dev_name() for device name in QIBJulian Wiedmann
Passing a custom name from the device driver is nice - but in practice it's only zfcp who has been using this. So we might as well hard-code a naming scheme in the qdio layer, so that qeth also benefits from it. Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Reviewed-by: Steffen Maier <maier@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-08-17scsi: zfcp: Fix use-after-free in request timeout handlersSteffen Maier
Before v4.15 commit 75492a51568b ("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: 75492a51568b ("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>
2020-08-06Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsiLinus Torvalds
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 ...
2020-07-08scsi: zfcp: Avoid benign overflow of the Request Queue's free-levelJulian Wiedmann
zfcp_qdio_send() and zfcp_qdio_int_req() run concurrently, adding and completing SBALs on the Request Queue. There's a theoretical race where zfcp_qdio_int_req() completes a number of SBALs & increments the queue's free-level _before_ zfcp_qdio_send() was able to decrement it. This can cause ->req_q_free to momentarily hold a value larger than QDIO_MAX_BUFFERS_PER_Q. Luckily zfcp_qdio_send() is always called under ->req_q_lock, and all readers of the free-level also take this lock. So we can trust that zfcp_qdio_send() will clean up such a temporary overflow before anyone can actually observe it. But it's still confusing and annoying to worry about. So adjust the code to avoid this race. Link: https://lore.kernel.org/r/7f61f59a1f8db270312e64644f9173b8f1ac895f.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>
2020-07-08scsi: zfcp: Replace open-coded list moveJulian Wiedmann
Instead of manually moving each element of the unit and port lists into our temporary on-stack lists, splice them over in one go. Link: https://lore.kernel.org/r/cacb179f49ece50fd4dce119c61252d632cdc1d4.1593780621.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>
2020-07-08scsi: zfcp: Clean up zfcp_erp_action_ready()Julian Wiedmann
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>
2020-07-08scsi: zfcp: Fix an outdated comment for zfcp_qdio_send()Julian Wiedmann
zfcp no longer uses the qdio PCI flag, update the comment. Link: https://lore.kernel.org/r/6717c26fc986bff8776d110e27c199b523684c63.1593780621.git.bblock@linux.ibm.com Fixes: 21ddaa53f92d ("[SCSI] zfcp: Remove PCI flag") Reviewed-by: Steffen Maier <maier@linux.ibm.com> Reviewed-by: Fedor Loshakov <loshakov@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>
2020-07-08scsi: zfcp: Use prandom_u32_max() for backoffGeorge Spelvin
We don't need crypto-grade random numbers for randomized backoffs. Instead use prandom_u32_max(ep_ro) which generates a pseudo-random number uniformly distributed in the interval [0, ep_ro). Link: https://lore.kernel.org/r/8fc7c4c4069ff1783f4a9ccd84a923f581a09ec5.1593780621.git.bblock@linux.ibm.com Reviewed-by: Steffen Maier <maier@linux.ibm.com> Signed-off-by: George Spelvin <lkml@sdf.org> Signed-off-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-06-24scsi: zfcp: Fix panic on ERP timeout for previously dismissed ERP actionSteffen Maier
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 75492a51568b ("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: 75492a51568b ("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>
2020-05-11scsi: zfcp: Move allocation of the shost object to after xconf- and xport-dataBenjamin Block
At the moment we allocate and register the Scsi_Host object corresponding to a zfcp adapter (FCP device) very early in the life cycle of the adapter - even before we fully discover and initialize the underlying firmware/hardware. This had the advantage that we could already use the Scsi_Host object, and fill in all its information during said discover and initialize. Due to commit 737eb78e82d5 ("block: Delay default elevator initialization") (first released in v5.4), we noticed a regression that would prevent us from using any storage volume if zfcp is configured with support for DIF or DIX (zfcp.dif=1 || zfcp.dix=1). Doing so would result in an illegal memory access as soon as the first request is sent with such an configuration. As example for a crash resulting from this: scsi host0: scsi_eh_0: sleeping scsi host0: zfcp qdio: 0.0.1900 ZFCP on SC 4bd using AI:1 QEBSM:0 PRI:1 TDD:1 SIGA: W AP scsi 0:0:0:0: scsi scan: INQUIRY pass 1 length 36 Unable to handle kernel pointer dereference in virtual kernel address space Failing address: 0000000000000000 TEID: 0000000000000483 Fault in home space mode while using kernel ASCE. AS:0000000035c7c007 R3:00000001effcc007 S:00000001effd1000 P:000000000000003d Oops: 0004 ilc:3 [#1] PREEMPT SMP DEBUG_PAGEALLOC Modules linked in: ... CPU: 1 PID: 783 Comm: kworker/u760:5 Kdump: loaded Not tainted 5.6.0-rc2-bb-next+ #1 Hardware name: ... Workqueue: scsi_wq_0 fc_scsi_scan_rport [scsi_transport_fc] Krnl PSW : 0704e00180000000 000003ff801fcdae (scsi_queue_rq+0x436/0x740 [scsi_mod]) R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 RI:0 EA:3 Krnl GPRS: 0fffffffffffffff 0000000000000000 0000000187150120 0000000000000000 000003ff80223d20 000000000000018e 000000018adc6400 0000000187711000 000003e0062337e8 00000001ae719000 0000000187711000 0000000187150000 00000001ab808100 0000000187150120 000003ff801fcd74 000003e0062336a0 Krnl Code: 000003ff801fcd9e: e310a35c0012 lt %r1,860(%r10) 000003ff801fcda4: a7840010 brc 8,000003ff801fcdc4 #000003ff801fcda8: e310b2900004 lg %r1,656(%r11) >000003ff801fcdae: d71710001000 xc 0(24,%r1),0(%r1) 000003ff801fcdb4: e310b2900004 lg %r1,656(%r11) 000003ff801fcdba: 41201018 la %r2,24(%r1) 000003ff801fcdbe: e32010000024 stg %r2,0(%r1) 000003ff801fcdc4: b904002b lgr %r2,%r11 Call Trace: [<000003ff801fcdae>] scsi_queue_rq+0x436/0x740 [scsi_mod] ([<000003ff801fcd74>] scsi_queue_rq+0x3fc/0x740 [scsi_mod]) [<00000000349c9970>] blk_mq_dispatch_rq_list+0x390/0x680 [<00000000349d1596>] blk_mq_sched_dispatch_requests+0x196/0x1a8 [<00000000349c7a04>] __blk_mq_run_hw_queue+0x144/0x160 [<00000000349c7ab6>] __blk_mq_delay_run_hw_queue+0x96/0x228 [<00000000349c7d5a>] blk_mq_run_hw_queue+0xd2/0xe0 [<00000000349d194a>] blk_mq_sched_insert_request+0x192/0x1d8 [<00000000349c17b8>] blk_execute_rq_nowait+0x80/0x90 [<00000000349c1856>] blk_execute_rq+0x6e/0xb0 [<000003ff801f8ac2>] __scsi_execute+0xe2/0x1f0 [scsi_mod] [<000003ff801fef98>] scsi_probe_and_add_lun+0x358/0x840 [scsi_mod] [<000003ff8020001c>] __scsi_scan_target+0xc4/0x228 [scsi_mod] [<000003ff80200254>] scsi_scan_target+0xd4/0x100 [scsi_mod] [<000003ff802d8b96>] fc_scsi_scan_rport+0x96/0xc0 [scsi_transport_fc] [<0000000034245ce8>] process_one_work+0x458/0x7d0 [<00000000342462a2>] worker_thread+0x242/0x448 [<0000000034250994>] kthread+0x15c/0x170 [<0000000034e1979c>] ret_from_fork+0x30/0x38 INFO: lockdep is turned off. Last Breaking-Event-Address: [<000003ff801fbc36>] scsi_add_cmd_to_list+0x9e/0xa8 [scsi_mod] Kernel panic - not syncing: Fatal exception: panic_on_oops While this issue is exposed by the commit named above, this is only by accident. The real issue exists for longer already - basically since it's possible to use blk-mq via scsi-mq, and blk-mq pre-allocates all requests for a tag-set during initialization of the same. For a given Scsi_Host object this is done when adding the object to the midlayer (`scsi_add_host()` and such). In `scsi_mq_setup_tags()` the midlayer calculates how much memory is required for a single scsi_cmnd, and its additional data, which also might include space for additional protection data - depending on whether the Scsi_Host has any form of protection capabilities (`scsi_host_get_prot()`). The problem is now thus, because zfcp does this step before we actually know whether the firmware/hardware has these capabilities, we don't set any protection capabilities in the Scsi_Host object. And so, no space is allocated for additional protection data for requests in the Scsi_Host tag-set. Once we go through discover and initialize the FCP device firmware/hardware fully (this is done via the firmware commands "Exchange Config Data" and "Exchange Port Data") we find out whether it actually supports DIF and DIX, and we set the corresponding capabilities in the Scsi_Host object (in `zfcp_scsi_set_prot()`). Now the Scsi_Host potentially has protection capabilities, but the already allocated requests in the tag-set don't have any space allocated for that. When we then trigger target scanning or add scsi_devices manually, the midlayer will use requests from that tag-set, and before sending most requests, it will also call `scsi_mq_prep_fn()`. To prepare the scsi_cmnd this function will check again whether the used Scsi_Host has any protection capabilities - and now it potentially has - and if so, it will try to initialize the assumed to be preallocated structures and thus it causes the crash, like shown above. Before delaying the default elevator initialization with the commit named above, we always would also allocate an elevator for any scsi_device before ever sending any requests - in contrast to now, where we do it after device-probing. That elevator in turn would have its own tag-set, and that is initialized after we went through discovery and initialization of the underlying firmware/hardware. So requests from that tag-set can be allocated properly, and if used - unless the user changes/disabled the default elevator - this would hide the underlying issue. To fix this for any configuration - with or without an elevator - we move the allocation and registration of the Scsi_Host object for a given FCP device to after the first complete discovery and initialization of the underlying firmware/hardware. By doing that we can make all basic properties of the Scsi_Host known to the midlayer by the time we call `scsi_add_host()`, including whether we have any protection capabilities. To do that we have to delay all the accesses that we would have done in the past during discovery and initialization, and do them instead once we are finished with it. The previous patches ramp up to this by fencing and factoring out all these accesses, and make it possible to re-do them later on. In addition we make also use of the diagnostic buffers we recently added with commit 92953c6e0aa7 ("scsi: zfcp: signal incomplete or error for sync exchange config/port data") commit 7e418833e689 ("scsi: zfcp: diagnostics buffer caching and use for exchange port data") commit 088210233e6f ("scsi: zfcp: add diagnostics buffer for exchange config data") (first released in v5.5), because these already cache all the information we need for that "re-do operation" - the information cached are always updated during xconf or xport data, so it won't be stale. In addition to the move and re-do, this patch also updates the function-documentation of `zfcp_scsi_adapter_register()` and changes how it reports if a Scsi_Host object already exists. In that case future recovery-operations can skip this step completely and behave much like they would do in the past - zfcp does not release a once allocated Scsi_Host object unless the corresponding FCP device is deconstructed completely. Link: https://lore.kernel.org/r/030dd6da318bbb529f0b5268ec65cebcd20fc0a3.1588956679.git.bblock@linux.ibm.com Reviewed-by: Steffen Maier <maier@linux.ibm.com> Signed-off-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-05-11scsi: zfcp: Fence early sysfs interfaces for accesses of shost objectsBenjamin Block
When setting an adapter online for the first time, we also create a couple of entries for it in the sysfs device tree. This is also true even if the adapter has not yet ever gone successfully through exchange config and exchange port data. When moving the scsi host object allocation and registration to after the first exchange config and exchange port data, this make the `port_rescan` attribute susceptible to invalid pointer-dereferences of the shost field before the adapter is fully initialized. When written to, it schedules a `scan_work` item that will in turn make use of the associated fibre channel host object to check the topology used for this FCP device. Because scanning for remote ports can't be done successfully without completing exchange config and exchange port data first, we can simply fence `port_rescan`, and so prevent the illegal access. As with cases where we can't get a reference to the adapter, we also return -ENODEV here. Applications need to handle that errno today already. After a successful allocation of the scsi host object nothing changes in the work flow. Link: https://lore.kernel.org/r/ef65366d309993ca91b6917727590ca7ca166c8f.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>