linux-dev/drivers/s390/scsi, branch master

s390: move from strlcpy with unused retval to strscpy

2022-08-30T20:00:33Z

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 Acked-by: Jakub Kicinski Acked-by: Benjamin Block Acked-by: Alexandra Winter 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

scsi: zfcp: Fix missing auto port scan and thus missing target ports

2022-08-01T23:50:00Z

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: #v2.6.28+ Reviewed-by: Benjamin Block Signed-off-by: Steffen Maier Signed-off-by: Martin K. Petersen

scsi: zfcp: Drop redundant "the" in the comments

2022-07-07T21:33:58Z

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 Signed-off-by: Jiang Jian Signed-off-by: Benjamin Block Signed-off-by: Martin K. Petersen

scsi: zfcp: Declare zfcp_sdev_attrs as static

2022-07-07T21:33:58Z

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 Signed-off-by: Julian Wiedmann Signed-off-by: Benjamin Block Signed-off-by: Martin K. Petersen

scsi: zfcp: Fix failed recovery on gone remote port with non-NPIV FCP devices

2022-01-25T04:30:27Z

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: #2.6.32+ Suggested-by: Benjamin Block Reviewed-by: Benjamin Block Signed-off-by: Steffen Maier Signed-off-by: Martin K. Petersen

s390/qdio: split do_QDIO()

2021-12-06T13:42:25Z

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 Reviewed-by: Benjamin Block Signed-off-by: Heiko Carstens

s390/qdio: split qdio_inspect_queue()

2021-12-06T13:42:25Z

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 Reviewed-by: Benjamin Block Signed-off-by: Heiko Carstens

scsi: zfcp: Switch to attribute groups

2021-10-17T01:45:53Z

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 Signed-off-by: Bart Van Assche Signed-off-by: Martin K. Petersen

scsi: zfcp_scsi: Call scsi_done() directly

2021-10-17T01:28:44Z

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 Signed-off-by: Bart Van Assche Signed-off-by: Martin K. Petersen

Merge tag 's390-5.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2021-09-09T19:55:12Z

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