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path: root/include/target/target_core_base.h
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2021-01-26scsi: target: core: Change ASCQ for residual writeAnastasia Kovaleva
According to FCP-4 (9.4.2): If the command requested that data beyond the length specified by the FCP_DL field be transferred, then the device server shall set the FCP_RESID_OVER bit (see 9.5.8) to one in the FCP_RSP IU and: a) process the command normally except that data beyond the FCP_DL count shall not be requested or transferred; b) transfer no data and return CHECK CONDITION status with the sense key set to ILLEGAL REQUEST and the additional sense code set to INVALID FIELD IN COMMAND INFORMATION UNIT; or c) may transfer data and return CHECK CONDITION status with the sense key set to ABORTED COMMAND and the additional sense code set to INVALID FIELD IN COMMAND INFORMATION UNIT. TCM follows b) and transfers no data for residual writes but returns INVALID FIELD IN CDB instead of INVALID FIELD IN COMMAND INFORMATION UNIT. Change the ASCQ to INVALID FIELD IN COMMAND INFORMATION UNIT to meet the standard. Link: https://lore.kernel.org/r/20201203082035.54566-4-a.kovaleva@yadro.com Signed-off-by: Anastasia Kovaleva <a.kovaleva@yadro.com> Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-11-04scsi: target: Make state_list per CPUMike Christie
Do a state_list/execute_task_lock per CPU, so we can do submissions from different CPUs without contention with each other. Note: tcm_fc was passing TARGET_SCF_USE_CPUID, but never set cpuid. The assumption is that it wanted to set the cpuid to the CPU it was submitting from so it will get this behavior with this patch. [mkp: s/printk/pr_err/ + resolve COMPARE AND WRITE patch conflict] Link: https://lore.kernel.org/r/1604257174-4524-8-git-send-email-michael.christie@oracle.com Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com> Signed-off-by: Mike Christie <michael.christie@oracle.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-11-04scsi: target: Drop sess_cmd_lock from I/O pathMike Christie
Drop the sess_cmd_lock by: - Removing the sess_cmd_list use from LIO core, because it's been moved to qla2xxx. - Removing sess_tearing_down check in the I/O path. Instead of using that bit and the sess_cmd_lock, we rely on the cmd_count percpu ref. To do this we switch to percpu_ref_kill_and_confirm/percpu_ref_tryget_live. Link: https://lore.kernel.org/r/1604257174-4524-7-git-send-email-michael.christie@oracle.com Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com> Signed-off-by: Mike Christie <michael.christie@oracle.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-11-04scsi: target: Remove TARGET_SCF_LOOKUP_LUN_FROM_TAGMike Christie
TARGET_SCF_LOOKUP_LUN_FROM_TAG is no longer used so remove it. Link: https://lore.kernel.org/r/1604257174-4524-5-git-send-email-michael.christie@oracle.com Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com> Signed-off-by: Mike Christie <michael.christie@oracle.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-11-04scsi: target: Rename cmd.bad_sector to cmd.sense_infoDavid Disseldorp
cmd.bad_sector currently gets packed into the sense INFORMATION field for TCM_LOGICAL_BLOCK_{GUARD,APP_TAG,REF_TAG}_CHECK_FAILED errors, which carry an .add_sector_info flag in the sense_detail_table to ensure this. In preparation for propagating a byte offset on COMPARE AND WRITE TCM_MISCOMPARE_VERIFY error, rename cmd.bad_sector to cmd.sense_info and sense_detail.add_sector_info to sense_detail.add_sense_info so that it better reflects the sense INFORMATION field destination. [ddiss: update previously overlooked ib_isert] Link: https://lore.kernel.org/r/20201031233211.5207-3-ddiss@suse.de Reviewed-by: Mike Christie <michael.christie@oracle.com> Signed-off-by: David Disseldorp <ddiss@suse.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-07-28scsi: target: Add tmr_notify backend functionBodo Stroesser
Target core is modified to call an optional backend callback function if a TMR is received or commands are aborted implicitly after a PR command was received. The backend function takes as parameters the se_dev, the type of the TMR, and the list of aborted commands. If no commands were aborted, an empty list is supplied. Link: https://lore.kernel.org/r/20200726153510.13077-3-bstroesser@ts.fujitsu.com Reviewed-by: Mike Christie <michael.christie@oracle.com> Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-05-07scsi: target: Make transport_flags per deviceBodo Stroesser
pgr_support and alua_support device attributes show the inverted value of the transport_flags: * TRANSPORT_FLAG_PASSTHROUGH_PGR * TRANSPORT_FLAG_PASSTHROUGH_ALUA These attributes are per device, while the flags are per backend. Rename the transport_flags in backend/transport to transport_flags_default and use this value to initialize the new transport_flags field in the se_device structure. Now data and attribute both are per se_device. Link: https://lore.kernel.org/r/20200427150823.15350-4-bstroesser@ts.fujitsu.com Reviewed-by: Mike Christie <mchristi@redhat.com> Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-02-21scsi: target: use an enum to track emulate_ua_intlck_ctrlDavid Disseldorp
The emulate_ua_intlck_ctrl device attribute accepts values of 0, 1 or 2 via ConfigFS, which map to unit attention interlocks control codes in the MODE SENSE control Mode Page. Use an enum to track these values so that it's clear that, unlike the remaining emulate_X attributes, emulate_ua_intlck_ctrl isn't boolean. Link: https://marc.info/?l=target-devel&m=158227825428798 Suggested-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: David Disseldorp <ddiss@suse.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-02-21scsi: target: convert boolean se_dev_attrib types to boolDavid Disseldorp
This should harden us against configfs API regressions similar to the one fixed by the previous commit. Link: https://marc.info/?l=target-devel&m=158211731505174 Signed-off-by: David Disseldorp <ddiss@suse.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-02-21scsi: target: fix unmap_zeroes_data boolean initialisationDavid Disseldorp
The LIO unmap_zeroes_data device attribute is mapped to the LBPRZ flag in the READ CAPACITY(16) and Thin Provisioning VPD INQUIRY responses. The unmap_zeroes_data attribute is exposed via configfs, where any write value is correctly validated via strtobool(). However, when initialised via target_configure_unmap_from_queue() it takes the value of the device's max_write_zeroes_sectors queue limit, which is non-boolean. A non-boolean value can be read from configfs, but attempting to write the same value back results in -EINVAL, causing problems for configuration utilities such as targetcli. Link: https://marc.info/?l=target-devel&m=158213354011309 Fixes: 2237498f0b5c ("target/iblock: Convert WRITE_SAME to blkdev_issue_zeroout") Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: David Disseldorp <ddiss@suse.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2019-10-03scsi: target: Remove tpg_list and se_portal_group.se_tpg_nodeBart Van Assche
Maintaining tpg_list without ever iterating over it is not useful. Hence remove tpg_list. This patch does not change the behavior of the SCSI target code. Cc: Mike Christie <mchristie@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.de> Cc: Nicholas Bellinger <nab@linux-iscsi.org> Link: https://lore.kernel.org/r/20190930232224.58980-1-bvanassche@acm.org Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Mike Christie <mchristi@redhat.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2019-04-12scsi: target/core: Rework the SPC-2 reservation handling codeBart Van Assche
Instead of tracking the initiator that established an SPC-2 reservation, track the session through which the SPC-2 reservation has been established. This patch does not change any functionality. Cc: Mike Christie <mchristi@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.com> Cc: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2019-02-04scsi: target/core: Remove several state tests from the TMF codeBart Van Assche
Whether or not a session is being torn down does not affect whether or not SCSI commands are in the task set. Hence remove the "tearing down" checks from the TMF code. The TRANSPORT_ISTATE_PROCESSING check is left out because it is now safe to wait for a command that is in that state. The CMD_T_PRE_EXECUTE is left out because abort processing is postponed until after commands have left the pre-execute state since the patch that makes TMF processing synchronous. See also commit 1c21a48055a6 ("target: Avoid early CMD_T_PRE_EXECUTE failures during ABORT_TASK"). Cc: Nicholas Bellinger <nab@linux-iscsi.org> Cc: Mike Christie <mchristi@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.de> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-12-07scsi: target: consistently null-terminate t10_wwn stringsDavid Disseldorp
In preparation for supporting user provided vendor strings, add an extra byte to the vendor, model and revision arrays in struct t10_wwn. This ensures that the full INQUIRY data can be carried in the arrays along with a null-terminator. Change a number of array readers and writers so that they account for explicit null-termination: - The pscsi_set_inquiry_info() and emulate_model_alias_store() codepaths don't currently explicitly null-terminate; fix this. - Existing t10_wwn field dumps use for-loops which step over null-terminators for right-padding. + Use printf with width specifiers instead. Signed-off-by: David Disseldorp <ddiss@suse.de> Reviewed-by: Roman Bolshakov <r.bolshakov@yadro.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-12-07scsi: target/core: Fix TAS handling for aborted commandsBart Van Assche
The TASK ABORTED STATUS (TAS) bit is defined as follows in SAM: "TASK_ABORTED: this status shall be returned if a command is aborted by a command or task management function on another I_T nexus and the control mode page TAS bit is set to one". TAS handling is spread over the target core and the iSCSI target driver. If a LUN RESET is received, the target core will send the TASK_ABORTED response for all commands for which such a response has to be sent. If an ABORT TASK is received, only the iSCSI target driver will send the TASK_ABORTED response for the commands for which that response has to be sent. That is a bug since all target drivers have to honor the TAS bit. Fix this by moving the code that handles TAS from the iSCSI target driver into the target core. Additionally, if a command has been aborted, instead of sending the TASK_ABORTED status from the context that processes the SCSI command send it from the context of the ABORT TMF. The core_tmr_abort_task() change in this patch causes the CMD_T_TAS flag to be set if a TASK_ABORTED status has to be sent back to the initiator that submitted the command. If that flag has been set transport_cmd_finish_abort() will send the TASK_ABORTED response. Cc: Nicholas Bellinger <nab@linux-iscsi.org> Cc: Mike Christie <mchristi@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: David Disseldorp <ddiss@suse.de> Cc: Hannes Reinecke <hare@suse.de> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-12-07scsi: target/core: Make it possible to wait from more than one context for ↵Bart Van Assche
command completion This patch does not change any functionality but makes the patch that makes TMF handling synchronous easier to read. Cc: Nicholas Bellinger <nab@linux-iscsi.org> Cc: Mike Christie <mchristi@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: David Disseldorp <ddiss@suse.de> Cc: Hannes Reinecke <hare@suse.de> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-12-07scsi: target/core: Use system workqueues for TMFBart Van Assche
A quote from SAM-5: "The order in which task management requests are processed is not specified by the SCSI architecture model. The SCSI architecture model does not require in-order delivery of such task management requests or processing by the task manager in the order received. To guarantee the processing order of task management requests referencing sent to a specific logical unit, an application client should not have more than one such task management request pending to that logical unit." This means that it is safe to use the system workqueues instead of tmr_wq for processing TMFs. An intended side effect of this patch is that it enables concurrent processing of TMFs. Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Nicholas Bellinger <nab@linux-iscsi.org> Cc: Mike Christie <mchristi@redhat.com> Cc: David Disseldorp <ddiss@suse.de> Cc: Hannes Reinecke <hare@suse.de> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-12-07scsi: target/core: Make sure that target_wait_for_sess_cmds() waits long enoughBart Van Assche
A session must only be released after all code that accesses the session structure has finished. Make sure that this is the case by introducing a new command counter per session that is only decremented after the .release_cmd() callback has finished. This patch fixes the following crash: BUG: KASAN: use-after-free in do_raw_spin_lock+0x1c/0x130 Read of size 4 at addr ffff8801534b16e4 by task rmdir/14805 CPU: 16 PID: 14805 Comm: rmdir Not tainted 4.18.0-rc2-dbg+ #5 Call Trace: dump_stack+0xa4/0xf5 print_address_description+0x6f/0x270 kasan_report+0x241/0x360 __asan_load4+0x78/0x80 do_raw_spin_lock+0x1c/0x130 _raw_spin_lock_irqsave+0x52/0x60 srpt_set_ch_state+0x27/0x70 [ib_srpt] srpt_disconnect_ch+0x1b/0xc0 [ib_srpt] srpt_close_session+0xa8/0x260 [ib_srpt] target_shutdown_sessions+0x170/0x180 [target_core_mod] core_tpg_del_initiator_node_acl+0xf3/0x200 [target_core_mod] target_fabric_nacl_base_release+0x25/0x30 [target_core_mod] config_item_release+0x9c/0x110 [configfs] config_item_put+0x26/0x30 [configfs] configfs_rmdir+0x3b8/0x510 [configfs] vfs_rmdir+0xb3/0x1e0 do_rmdir+0x262/0x2c0 do_syscall_64+0x77/0x230 entry_SYSCALL_64_after_hwframe+0x49/0xbe Cc: Nicholas Bellinger <nab@linux-iscsi.org> Cc: Mike Christie <mchristi@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: David Disseldorp <ddiss@suse.de> Cc: Hannes Reinecke <hare@suse.de> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-12-07scsi: target/core: Simplify transport_clear_lun_ref()Bart Van Assche
Since transport_clear_lun_ref() already waits until the percpu-refcount .release() method is called, it is not necessary to wait first until percpu_ref_kill_and_confirm() has finished transitioning the refcount into atomic mode. Remove the code that waits for percpu_ref_kill_and_confirm() to complete and also the completion object that is used by that code. This patch does not change the behavior of the SCSI target code. Cc: Nicholas Bellinger <nab@linux-iscsi.org> Cc: Mike Christie <mchristi@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: David Disseldorp <ddiss@suse.de> Cc: Hannes Reinecke <hare@suse.de> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-11-28scsi: target: drop unused pi_prot_format attribute storageDavid Disseldorp
On write, the pi_prot_format configfs attribute invokes the device format_prot() callback if present. Read dumps the contents of se_dev_attrib.pi_prot_format which is always zero. Make the configfs attribute write-only, and drop the always zero se_dev_attrib.pi_prot_format storage. Signed-off-by: David Disseldorp <ddiss@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-11-21scsi: target: add emulate_pr backstore attr to toggle PR supportDavid Disseldorp
The new emulate_pr backstore attribute allows for Persistent Reservation and SCSI2 RESERVE/RELEASE support to be completely disabled. This can be useful for scenarios such as: - Ensuring ATS (Compare & Write) usage on recent VMware ESXi initiators. - Allowing clustered (e.g. tcm-user) backends to block such requests, avoiding the multi-node reservation state propagation. When explicitly disabled, PR and RESERVE/RELEASE requests receive Invalid Command Operation Code response sense data. Signed-off-by: David Disseldorp <ddiss@suse.de> Reviewed-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-10-16scsi: target/core: Remove the SCF_COMPARE_AND_WRITE_POST flagBart Van Assche
Commit 057085e522f8 ("target: Fix race for SCF_COMPARE_AND_WRITE_POST checking") removed the code that checks the SCF_COMPARE_AND_WRITE_POST flag. Hence also remove the flag itself. Cc: Nicholas Bellinger <nab@linux-iscsi.org> Cc: Mike Christie <mchristi@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.de> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-07-02scsi: target: Remove se_dev_entry.ua_countBart Van Assche
se_dev_entry.ua_count is only used to check whether or not se_dev_entry.ua_list is empty. Use list_empty_careful() instead. Checking whether or not ua_list is empty without holding the lock that protects that list is fine because the code that dequeues from that list will check again whether or not that list is empty. Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Mike Christie <mchristi@redhat.com> Cc: Mike Christie <mchristi@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-07-02scsi: target: Simplify the code for waiting for command completionBart Van Assche
Instead of embedding the completion that is used for waiting for command completion in struct se_cmd, let the context that waits for command completion allocate it. This makes it possible to have a single code path for non-aborted and aborted commands in target_release_cmd_kref() and avoids that transport_generic_free_cmd() has to call cmd->se_tfo->release_cmd() directly. This patch does not change any functionality. Note: transport_generic_free_cmd() only waits until the se_cmd reference count has reached zero after it has set both CMD_T_FABRIC_STOP and CMD_T_ABORTED. Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Mike Christie <mchristi@redhat.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-07-02scsi: target: Make the session shutdown code also wait for commands that are ↵Bart Van Assche
being aborted Target drivers must call target_sess_cmd_list_set_waiting() and target_wait_for_sess_cmds() before freeing a session. Since freeing a session is only safe after all commands that are associated with a session have finished, make target_wait_for_sess_cmds() also wait for commands that are being aborted. Instead of setting a flag in each pending command from target_sess_cmd_list_set_waiting() and waiting in target_wait_for_sess_cmds() on a per-command completion, only set a per-session flag in the former function and wait on a per-session completion in the latter function. This change is safe because once a SCSI initiator system has submitted a command a target system is always allowed to execute it to completion. See also commit 0f4a943168f3 ("target: Fix remote-port TMR ABORT + se_cmd fabric stop"). This patch is based on the following two patches: * Bart Van Assche, target: Simplify session shutdown code, February 19, 2015 (https://github.com/bvanassche/linux/commit/8df5463d7d7619f2f1b70cfe5172eaef0aa52815). * Christoph Hellwig, target: Rework session shutdown code, December 7, 2015 (http://thread.gmane.org/gmane.linux.scsi.target.devel/10695). Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Mike Christie <mchristi@redhat.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Sagi Grimberg <sagig@mellanox.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-06-19scsi: target: Convert target drivers to use sbitmapMatthew Wilcox
The sbitmap and the percpu_ida perform essentially the same task, allocating tags for commands. The sbitmap outperforms the percpu_ida as documented here: https://lkml.org/lkml/2014/4/22/553 The sbitmap interface is a little harder to use, but being able to remove the percpu_ida code and getting better performance justifies the additional complexity. Signed-off-by: Matthew Wilcox <willy@infradead.org> Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com> # f_tcm Reviewed-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-06-19scsi: target: Abstract tag freeingMatthew Wilcox
Introduce target_free_tag() and convert all drivers to use it. Signed-off-by: Matthew Wilcox <willy@infradead.org> Reviewed-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-05-18scsi: target: transport should handle st FM/EOM/ILI readsLee Duncan
When a tape drive is exported via LIO using the pscsi module, a read that requests more bytes per block than the tape can supply returns an empty buffer. This is because the pscsi pass-through target module sees the "ILI" illegal length bit set and thinks there is no reason to return the data. This is a long-standing transport issue, since it assumes that no data need be returned under a check condition, which isn't always the case for tape. Add in a check for tape reads with the ILI, EOM, or FM bits set, with a sense code of NO_SENSE, treating such cases as if the read succeeded. The layered tape driver then "does the right thing" when it gets such a response. Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com> Signed-off-by: Lee Duncan <lduncan@suse.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-01-16target core: add device action configfs filesMike Christie
This patch adds a new group of files that are to be used to have the kernel module execution some action. The next patch will have target_core_user use the group/files to be able to block a device and to reset its memory buffer used to pass commands between user/kernel space. This type of file is different from the existing device attributes in that they may be write only and when written to they result in the kernel module executing some function. These need to be separate from the normal device attributes which get/set device values so userspace can continue to loop over all the attribs and get/set them during initialization. Signed-off-by: Mike Christie <mchristi@redhat.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2018-01-12target: add SAM_STAT_BUSY sense reasonMike Christie
Add SAM_STAT_BUSY sense_reason. The next patch will have target_core_user return this value while it is temporarily blocked and restarting. Signed-off-by: Mike Christie <mchristi@redhat.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-11-24Merge branch 'for-next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending Pull SCSI target updates from Nicholas Bellinger: "This series is predominantly bug-fixes, with a few small improvements that have been outstanding over the last release cycle. As usual, the associated bug-fixes have CC' tags for stable. Also, things have been particularly quiet wrt new developments the last months, with most folks continuing to focus on stability atop 4.x stable kernels for their respective production configurations. Also at this point, the stable trees have been synced up with mainline. This will continue to be a priority, as production users tend to run exclusively atop stable kernels, a few releases behind mainline. The highlights include: - Fix PR PREEMPT_AND_ABORT null pointer dereference regression in v4.11+ (tangwenji) - Fix OOPs during removing TCMU device (Xiubo Li + Zhang Zhuoyu) - Add netlink command reply supported option for each device (Kenjiro Nakayama) - cxgbit: Abort the TCP connection in case of data out timeout (Varun Prakash) - Fix PR/ALUA file path truncation (David Disseldorp) - Fix double se_cmd completion during ->cmd_time_out (Mike Christie) - Fix QUEUE_FULL + SCSI task attribute handling in 4.1+ (Bryant Ly + nab) - Fix quiese during transport_write_pending_qf endless loop (nab) - Avoid early CMD_T_PRE_EXECUTE failures during ABORT_TASK in 3.14+ (Don White + nab)" * 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (35 commits) tcmu: Add a missing unlock on an error path tcmu: Fix some memory corruption iscsi-target: Fix non-immediate TMR reference leak iscsi-target: Make TASK_REASSIGN use proper se_cmd->cmd_kref target: Avoid early CMD_T_PRE_EXECUTE failures during ABORT_TASK target: Fix quiese during transport_write_pending_qf endless loop target: Fix caw_sem leak in transport_generic_request_failure target: Fix QUEUE_FULL + SCSI task attribute handling iSCSI-target: Use common error handling code in iscsi_decode_text_input() target/iscsi: Detect conn_cmd_list corruption early target/iscsi: Fix a race condition in iscsit_add_reject_from_cmd() target/iscsi: Modify iscsit_do_crypto_hash_buf() prototype target/iscsi: Fix endianness in an error message target/iscsi: Use min() in iscsit_dump_data_payload() instead of open-coding it target/iscsi: Define OFFLOAD_BUF_SIZE once target: Inline transport_put_cmd() target: Suppress gcc 7 fallthrough warnings target: Move a declaration of a global variable into a header file tcmu: fix double se_cmd completion target: return SAM_STAT_TASK_SET_FULL for TCM_OUT_OF_RESOURCES ...
2017-11-07target: Avoid early CMD_T_PRE_EXECUTE failures during ABORT_TASKNicholas Bellinger
This patch fixes bug where early se_cmd exceptions that occur before backend execution can result in use-after-free if/when a subsequent ABORT_TASK occurs for the same tag. Since an early se_cmd exception will have had se_cmd added to se_session->sess_cmd_list via target_get_sess_cmd(), it will not have CMD_T_COMPLETE set by the usual target_complete_cmd() backend completion path. This causes a subsequent ABORT_TASK + __target_check_io_state() to signal ABORT_TASK should proceed. As core_tmr_abort_task() executes, it will bring the outstanding se_cmd->cmd_kref count down to zero releasing se_cmd, after se_cmd has already been queued with error status into fabric driver response path code. To address this bug, introduce a CMD_T_PRE_EXECUTE bit that is set at target_get_sess_cmd() time, and cleared immediately before backend driver dispatch in target_execute_cmd() once CMD_T_ACTIVE is set. Then, check CMD_T_PRE_EXECUTE within __target_check_io_state() to determine when an early exception has occured, and avoid aborting this se_cmd since it will have already been queued into fabric driver response path code. Reported-by: Donald White <dew@datera.io> Cc: Donald White <dew@datera.io> Cc: Mike Christie <mchristi@redhat.com> Cc: Hannes Reinecke <hare@suse.com> Cc: stable@vger.kernel.org # 3.14+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-11-04target: add sense code INSUFFICIENT REGISTRATION RESOURCEStangwenji
If a PERSISTENT RESERVE OUT command with a REGISTER service action or a REGISTER AND IGNORE EXISTING KEY service action or REGISTER AND MOVE service action is attempted, but there are insufficient device server resources to complete the operation, then the command shall be terminated with CHECK CONDITION status, with the sense key set to ILLEGAL REQUEST,and the additonal sense code set to INSUFFICIENT REGISTRATION RESOURCES. Signed-off-by: tangwenji <tang.wenji@zte.com.cn> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-06target: remove g_device_listMike Christie
g_device_list is no longer needed because we now use the idr code for lookups and seaches. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-07-06target: use idr for se_device dev indexMike Christie
In the next patches we will add tcmu netlink support that allows userspace to send commands to target_core_user. To execute operations on a se_device/tcmu_dev we need to be able to look up a dev by any old id. This patch replaces the se_device->dev_index with a idr created id. The next patches will also remove the g_device_list and replace it with the idr. Signed-off-by: Mike Christie <mchristi@redhat.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-07-06target: Remove se_device.dev_listBart Van Assche
The last user of se_device.dev_list was removed through commit 0fd97ccf45be ("target: kill struct se_subsystem_dev"). Hence also remove se_device.dev_list. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Andy Grover <agrover@redhat.com> Cc: David Disseldorp <ddiss@suse.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-07-06target: Add TARGET_SCF_LOOKUP_LUN_FROM_TAG support for ABORT_TASKNicholas Bellinger
This patch introduces support in target_submit_tmr() for locating a unpacked_lun from an existing se_cmd->tag during ABORT_TASK. When TARGET_SCF_LOOKUP_LUN_FROM_TAG is set, target_submit_tmr() will do the extra lookup via target_lookup_lun_from_tag() and subsequently invoke transport_lookup_tmr_lun() so a proper percpu se_lun->lun_ref is taken before workqueue dispatch into se_device->tmr_wq happens. Aside from the extra target_lookup_lun_from_tag(), the existing code-path remains unchanged. Reviewed-by: Himanshu Madhani <himanshu.madhani@cavium.com> Reviewed-by: Quinn Tran <quinn.tran@cavium.com> Cc: Mike Christie <mchristi@redhat.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-06-08target/configfs: Kill se_lun->lun_link_magicNicholas Bellinger
Instead of using a hardcoded magic value in se_lun when verifying a target config_item symlink source during target_fabric_mappedlun_link(), go ahead and use target_fabric_port_item_ops directly instead. Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Mike Christie <mchristi@redhat.com> Cc: Hannes Reinecke <hare@suse.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-06-08target/configfs: Kill se_device->dev_link_magicNicholas Bellinger
Instead of using a hardcoded magic value in se_device when verifying a target config_item symlink source during target_fabric_port_link(), go ahead and use target_core_dev_item_ops directly instead. Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Mike Christie <mchristi@redhat.com> Cc: Hannes Reinecke <hare@suse.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-05-01tcm: make pi data verification configurableDmitry Monakhov
Currently ramdisk and fileio always perform PI verification before and after backend IO. This approach is not very flexible. Because some one may want to postpone this work to other layers in IO stack. For example if we want to test blk_integrity_profile testcase: https://github.com/dmonakhov/xfstests/commit/dee408c868861d6b6871dbb3381facee7effdbe4 Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-03-30target: Fix ALUA transition state race between multiple initiatorsMike Christie
Multiple threads could be writing to alua_access_state at the same time, or there could be multiple STPGs in flight (different initiators sending them or one initiator sending them to different ports), or a combo of both and the core_alua_do_transition_tg_pt calls will race with each other. Because from the last patches we no longer delay running core_alua_do_transition_tg_pt_work, there does not seem to be any point in running that in a workqueue. And, we always wait for it to complete one way or another, so we can sleep in this code path. So, this patch made over target-pending just adds a mutex and does the work core_alua_do_transition_tg_pt_work was doing in core_alua_do_transition_tg_pt. There is also no need to use an atomic for the tg_pt_gp_alua_access_state. In core_alua_do_transition_tg_pt we will test and set it under the transition mutex. And, it is a int/32 bits so in the other places where it is read, we will never see it partially updated. Signed-off-by: Mike Christie <mchristi@redhat.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-03-30target: Fix unknown fabric callback queue-full errorsNicholas Bellinger
This patch fixes a set of queue-full response handling bugs, where outgoing responses are leaked when a fabric driver is propagating non -EAGAIN or -ENOMEM errors to target-core. It introduces TRANSPORT_COMPLETE_QF_ERR state used to signal when CHECK_CONDITION status should be generated, when fabric driver ->write_pending(), ->queue_data_in(), or ->queue_status() callbacks fail with non -EAGAIN or -ENOMEM errors, and data-transfer should not be retried. Note all fabric driver -EAGAIN and -ENOMEM errors are still retried indefinately with associated data-transfer callbacks, following existing queue-full logic. Also fix two missing ->queue_status() queue-full cases related to CMD_T_ABORTED w/ TAS status handling. Reported-by: Potnuri Bharat Teja <bharat@chelsio.com> Reviewed-by: Potnuri Bharat Teja <bharat@chelsio.com> Tested-by: Potnuri Bharat Teja <bharat@chelsio.com> Cc: Potnuri Bharat Teja <bharat@chelsio.com> Reported-by: Steve Wise <swise@opengridcomputing.com> Cc: Steve Wise <swise@opengridcomputing.com> Cc: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-03-30target: Avoid mappedlun symlink creation during lun shutdownNicholas Bellinger
This patch closes a race between se_lun deletion during configfs unlink in target_fabric_port_unlink() -> core_dev_del_lun() -> core_tpg_remove_lun(), when transport_clear_lun_ref() blocks waiting for percpu_ref RCU grace period to finish, but a new NodeACL mappedlun is added before the RCU grace period has completed. This can happen in target_fabric_mappedlun_link() because it only checks for se_lun->lun_se_dev, which is not cleared until after transport_clear_lun_ref() percpu_ref RCU grace period finishes. This bug originally manifested as NULL pointer dereference OOPsen in target_stat_scsi_att_intr_port_show_attr_dev() on v4.1.y code, because it dereferences lun->lun_se_dev without a explicit NULL pointer check. In post v4.1 code with target-core RCU conversion, the code in target_stat_scsi_att_intr_port_show_attr_dev() no longer uses se_lun->lun_se_dev, but the same race still exists. To address the bug, go ahead and set se_lun>lun_shutdown as early as possible in core_tpg_remove_lun(), and ensure new NodeACL mappedlun creation in target_fabric_mappedlun_link() fails during se_lun shutdown. Reported-by: James Shen <jcs@datera.io> Cc: James Shen <jcs@datera.io> Tested-by: James Shen <jcs@datera.io> Cc: stable@vger.kernel.org # 3.10+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-03-18target: fix ALUA transition timeout handlingMike Christie
The implicit transition time tells initiators the min time to wait before timing out a transition. We currently schedule the transition to occur in tg_pt_gp_implicit_trans_secs seconds so there is no room for delays. If core_alua_do_transition_tg_pt_work->core_alua_update_tpg_primary_metadata needs to write out info to a remote file, then the initiator can easily time out the operation. Signed-off-by: Mike Christie <mchristi@redhat.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-03-03Merge branch 'WIP.sched-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull sched.h split-up from Ingo Molnar: "The point of these changes is to significantly reduce the <linux/sched.h> header footprint, to speed up the kernel build and to have a cleaner header structure. After these changes the new <linux/sched.h>'s typical preprocessed size goes down from a previous ~0.68 MB (~22K lines) to ~0.45 MB (~15K lines), which is around 40% faster to build on typical configs. Not much changed from the last version (-v2) posted three weeks ago: I eliminated quirks, backmerged fixes plus I rebased it to an upstream SHA1 from yesterday that includes most changes queued up in -next plus all sched.h changes that were pending from Andrew. I've re-tested the series both on x86 and on cross-arch defconfigs, and did a bisectability test at a number of random points. I tried to test as many build configurations as possible, but some build breakage is probably still left - but it should be mostly limited to architectures that have no cross-compiler binaries available on kernel.org, and non-default configurations" * 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (146 commits) sched/headers: Clean up <linux/sched.h> sched/headers: Remove #ifdefs from <linux/sched.h> sched/headers: Remove the <linux/topology.h> include from <linux/sched.h> sched/headers, hrtimer: Remove the <linux/wait.h> include from <linux/hrtimer.h> sched/headers, x86/apic: Remove the <linux/pm.h> header inclusion from <asm/apic.h> sched/headers, timers: Remove the <linux/sysctl.h> include from <linux/timer.h> sched/headers: Remove <linux/magic.h> from <linux/sched/task_stack.h> sched/headers: Remove <linux/sched.h> from <linux/sched/init.h> sched/core: Remove unused prefetch_stack() sched/headers: Remove <linux/rculist.h> from <linux/sched.h> sched/headers: Remove the 'init_pid_ns' prototype from <linux/sched.h> sched/headers: Remove <linux/signal.h> from <linux/sched.h> sched/headers: Remove <linux/rwsem.h> from <linux/sched.h> sched/headers: Remove the runqueue_is_locked() prototype sched/headers: Remove <linux/sched.h> from <linux/sched/hotplug.h> sched/headers: Remove <linux/sched.h> from <linux/sched/debug.h> sched/headers: Remove <linux/sched.h> from <linux/sched/nohz.h> sched/headers: Remove <linux/sched.h> from <linux/sched/stat.h> sched/headers: Remove the <linux/gfp.h> include from <linux/sched.h> sched/headers: Remove <linux/rtmutex.h> from <linux/sched.h> ...
2017-03-03sched/headers: Remove <linux/cgroup-defs.h> from <linux/sched.h>Ingo Molnar
It's not used by anything in <linux/sched.h> anymore. This reduces the preprocessed size of <linux/sched.h> and speeds up the build a bit. Also fix code that implicitly relied on headers included by <linux/cgroup-defs.h>. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02Merge branch 'for-next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending Pull SCSI target updates from Nicholas Bellinger: "The highlights this round include: - enable dual mode (initiator + target) qla2xxx operation. (Quinn + Himanshu) - add a framework for qla2xxx async fabric discovery. (Quinn + Himanshu) - enable iscsi PDU DDP completion offload in cxgbit/T6 NICs. (Varun) - fix target-core handling of aborted failed commands. (Bart) - fix a long standing target-core issue NULL pointer dereference with active I/O LUN shutdown. (Rob Millner + Bryant + nab)" * 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (44 commits) target: Add counters for ABORT_TASK success + failure iscsi-target: Fix early login failure statistics misses target: Fix NULL dereference during LUN lookup + active I/O shutdown target: Delete tmr from list before processing target: Fix handling of aborted failed commands uapi: fix linux/target_core_user.h userspace compilation errors target: export protocol identifier qla2xxx: Fix a warning reported by the "smatch" static checker target/iscsi: Fix unsolicited data seq_end_offset calculation target/cxgbit: add T6 iSCSI DDP completion feature target/cxgbit: Enable DDP for T6 only if data sequence and pdu are in order target/cxgbit: Use T6 specific macros to get ETH/IP hdr len target/cxgbit: use cxgb4_tp_smt_idx() to get smt idx target/iscsi: split iscsit_check_dataout_hdr() target: Remove command flag CMD_T_DEV_ACTIVE target: Remove command flag CMD_T_BUSY target: Move session check from target_put_sess_cmd() into target_release_cmd_kref() target: Inline transport_cmd_check_stop() target: Remove an overly chatty debug message target: Stop execution if CMD_T_STOP has been set ...
2017-03-02sched/headers: Prepare to remove spurious <linux/sched.h> inclusion dependenciesIngo Molnar
In the following patches we are going to remove various headers from sched.h and other headers that sched.h includes. To make those patches build cleanly prepare the scene by adding dependencies to various files that learned to rely on those to-be-removed dependencies. These changes all make sense standalone: they add a header for a data type that a particular .c or .h file is using. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-26target: Add counters for ABORT_TASK success + failureNicholas Bellinger
This patch introduces two counters for ABORT_TASK success + failure under: /sys/kernel/config/target/core/$HBA/$DEV/statistics/scsi_tgt_dev/ that are useful for diagnosing various backend device latency and front fabric issues. Normally when folks see alot of aborts_complete happening, it means the backend device I/O completion latency is high, and not returning completions fast enough before host side timeouts trigger. And normally when folks see alot of aborts_no_task, it means completions are being posted by target-core into fabric driver code, but the responses aren't making it back to the host. Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>