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path: root/drivers/target/target_core_tmr.c
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2021-10-26scsi: target: core: Remove from tmr_list during LUN unlinkDmitry Bogdanov1-16/+1
Currently TMF commands are removed from de_device.dev_tmf_list at the very end of se_cmd lifecycle. However, se_lun unlinks from se_cmd upon a command status (response) being queued in transport layer. This means that LUN and backend device can be deleted in the meantime and a panic will occur: target_tmr_work() cmd->se_tfo->queue_tm_rsp(cmd); // send abort_rsp to a wire transport_lun_remove_cmd(cmd) // unlink se_cmd from se_lun - // - // - // - <<<--- lun remove <<<--- core backend device remove - // - // - // - qlt_handle_abts_completion() tfo->free_mcmd() transport_generic_free_cmd() target_put_sess_cmd() core_tmr_release_req() { if (dev) { // backend device, can not be null spin_lock_irqsave(&dev->se_tmr_lock, flags); //<<<--- CRASH Call Trace: NIP [c000000000e1683c] _raw_spin_lock_irqsave+0x2c/0xc0 LR [c00800000e433338] core_tmr_release_req+0x40/0xa0 [target_core_mod] Call Trace: (unreliable) 0x0 target_put_sess_cmd+0x2a0/0x370 [target_core_mod] transport_generic_free_cmd+0x6c/0x1b0 [target_core_mod] tcm_qla2xxx_complete_mcmd+0x28/0x50 [tcm_qla2xxx] process_one_work+0x2c4/0x5c0 worker_thread+0x88/0x690 For the iSCSI protocol this is easily reproduced: - Send some SCSI sommand - Send Abort of that command over iSCSI - Remove LUN on target - Send next iSCSI command to acknowledge the Abort_Response - Target panics There is no need to keep the command in tmr_list until response completion, so move the removal from tmr_list from the response completion to the response queueing when the LUN is unlinked. Move the removal from state list too as it is a subject to the same race condition. Link: https://lore.kernel.org/r/20211018135753.15297-1-d.bogdanov@yadro.com Fixes: c66ac9db8d4a ("[SCSI] target: Add LIO target core v4.0.0-rc6") Reviewed-by: Roman Bolshakov <r.bolshakov@yadro.com> Reviewed-by: Mike Christie <michael.christie@oracle.com> Signed-off-by: Dmitry Bogdanov <d.bogdanov@yadro.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-03-04scsi: target: core: Flush submission work during TMR processingMike Christie1-0/+4
If a cmd is on the submission workqueue then the TMR code will miss it, and end up returning task not found or success for LUN resets. The fabric driver might then tell the initiator that the running cmds have been handled when they are about to run. This adds a flush when we are processing TMRs to make sure queued cmds do not run after returning the TMR response. Link: https://lore.kernel.org/r/20210227170006.5077-25-michael.christie@oracle.com Tested-by: Laurence Oberman <loberman@redhat.com> Reviewed-by: Bodo Stroesser <bostroesser@gmail.com> Signed-off-by: Mike Christie <michael.christie@oracle.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-11-04scsi: target: Make state_list per CPUMike Christie1-79/+87
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>
2020-07-28scsi: target: Add tmr_notify backend functionBodo Stroesser1-1/+15
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>
2020-07-28scsi: target: Modify core_tmr_abort_task()Bodo Stroesser1-8/+14
This patch modifies core_tmr_abort_task() to use same looping and locking scheme as core_tmr_drain_state_list() does. This frees the state_list element in se_cmd for later use by tmr notification handling. Note: __target_check_io_state() now is called with param 0 instead of dev->dev_attrib.emulate_tas, because tas is not relevant since we always get ABRT on same session like the aborted command. Link: https://lore.kernel.org/r/20200726153510.13077-2-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>
2020-06-09scsi: target: Initialize LUN in transport_init_se_cmd()Sudhakar Panneerselvam1-2/+2
Initialization of orig_fe_lun is moved to transport_init_se_cmd() from transport_lookup_cmd_lun(). This helps for the cases where the SCSI request fails before the call to transport_lookup_cmd_lun() so that trace_target_cmd_complete() can print the LUN information to the trace buffer. Due to this change, the lun parameter is removed from transport_lookup_cmd_lun() and transport_lookup_tmr_lun(). Link: https://lore.kernel.org/r/1591559913-8388-3-git-send-email-sudhakar.panneerselvam@oracle.com Reviewed-by: Mike Christie <michael.christie@oracle.com> Signed-off-by: Sudhakar Panneerselvam <sudhakar.panneerselvam@oracle.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-02-21scsi: target: convert boolean se_dev_attrib types to boolDavid Disseldorp1-3/+3
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>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156Thomas Gleixner1-14/+1
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1334 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-12scsi: target/core: Rework the SPC-2 reservation handling codeBart Van Assche1-1/+1
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: Simplify the LUN RESET implementationBart Van Assche1-12/+2
Due to the task management handling rework it is safe to wait for a TMF that is not in the active state. Hence remove the CMD_T_ACTIVE test from core_tmr_drain_tmr_list(). Additionally, call __target_check_io_state() instead of open coding it. Reviewed-by: Hannes Reinecke <hare@suse.com> Cc: Nicholas Bellinger <nab@linux-iscsi.org> Cc: Mike Christie <mchristi@redhat.com> Cc: Christoph Hellwig <hch@lst.de> 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 Assche1-25/+0
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/core: Make ABORT and LUN RESET handling synchronousBart Van Assche1-21/+28
Instead of invoking target driver callback functions from the context that handles an abort or LUN RESET task management function, only set the abort flag from that context and perform the actual abort handling from the context of the regular command processing flow. This approach has the advantage that the task management code becomes much easier to read and to verify since the number of potential race conditions against the command processing flow is strongly reduced. This patch has been tested by running the following two shell commands concurrently for about ten minutes for both the iSCSI and the SRP target drivers ($dev is an initiator device node connected with storage provided by the target driver under test): * fio with data verification enabled on a filesystem mounted on top of $dev. * while true; do sg_reset -d $dev; echo -n .; sleep .1; done 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: Fix TAS handling for aborted commandsBart Van Assche1-1/+2
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>
2018-11-28scsi: target: drop unnecessary get_fabric_name() accessor from fabric_opsDavid Disseldorp1-2/+2
All fabrics return a const string. In all cases *except* iSCSI the get_fabric_name() string matches fabric_ops.name. Both fabric_ops.get_fabric_name() and fabric_ops.name are user-facing, with the former being used for PR/ALUA state and the latter for ConfigFS (config/target/$name), so we unfortunately need to keep both strings around for now. Replace the useless .get_fabric_name() accessor function with a const string fabric_name member variable. 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>
2018-07-02scsi: target: Fold core_tmr_handle_tas_abort() into transport_cmd_finish_abort()Bart Van Assche1-13/+3
For the two calls to transport_cmd_finish_abort() outside core_tmr_handle_tas_abort() it is guaranteed that CMD_T_TAS is not set. Use this property to fold core_tmr_handle_tas_abort() into transport_cmd_finish_abort(). This patch does not change any functionality. 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: Simplify core_tmr_handle_tas_abort()Bart Van Assche1-12/+3
The code that can set CMD_T_TAS is executed by the same thread as the thread that executes core_tmr_handle_tas_abort(). That means that no locking is needed to check CMD_T_TAS from inside core_tmr_handle_tas_abort(). This patch does not change any functionality. 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 Assche1-3/+2
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>
2017-11-07target: Avoid early CMD_T_PRE_EXECUTE failures during ABORT_TASKNicholas Bellinger1-0/+9
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: fix null pointer regression in core_tmr_drain_tmr_listtangwenji1-1/+2
The target system kernel crash when the initiator executes the sg_persist -A command,because of the second argument to be set to NULL when core_tmr_lun_reset is called in core_scsi3_pro_preempt function. This fixes a regression originally introduced by: commit 51ec502a32665fed66c7f03799ede4023b212536 Author: Bart Van Assche <bart.vanassche@sandisk.com> Date: Tue Feb 14 16:25:54 2017 -0800 target: Delete tmr from list before processing Signed-off-by: tangwenji <tang.wenji@zte.com.cn> Cc: stable@vger.kernel.org # 4.11+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-07-06target: Introduce a function that shows the command stateBart Van Assche1-14/+4
Introduce target_show_cmd() and use it where appropriate. If transport_wait_for_tasks() takes too long, make it show the state of the command it is waiting for. (Add missing brackets around multi-line conditions - nab) Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Hannes Reinecke <hare@suse.com> Cc: 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>
2017-06-08target: Fix kref->refcount underflow in transport_cmd_finish_abortNicholas Bellinger1-8/+8
This patch fixes a se_cmd->cmd_kref underflow during CMD_T_ABORTED when a fabric driver drops it's second reference from below the target_core_tmr.c based callers of transport_cmd_finish_abort(). Recently with the conversion of kref to refcount_t, this bug was manifesting itself as: [705519.601034] refcount_t: underflow; use-after-free. [705519.604034] INFO: NMI handler (kgdb_nmi_handler) took too long to run: 20116.512 msecs [705539.719111] ------------[ cut here ]------------ [705539.719117] WARNING: CPU: 3 PID: 26510 at lib/refcount.c:184 refcount_sub_and_test+0x33/0x51 Since the original kref atomic_t based kref_put() didn't check for underflow and only invoked the final callback when zero was reached, this bug did not manifest in practice since all se_cmd memory is using preallocated tags. To address this, go ahead and propigate the existing return from transport_put_cmd() up via transport_cmd_finish_abort(), and change transport_cmd_finish_abort() + core_tmr_handle_tas_abort() callers to only do their local target_put_sess_cmd() if necessary. Reported-by: Bart Van Assche <bart.vanassche@sandisk.com> Tested-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Mike Christie <mchristi@redhat.com> Cc: Hannes Reinecke <hare@suse.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Himanshu Madhani <himanshu.madhani@qlogic.com> Cc: Sagi Grimberg <sagig@mellanox.com> Cc: stable@vger.kernel.org # 3.14+ Tested-by: Gary Guo <ghg@datera.io> Tested-by: Chu Yuan Lin <cyl@datera.io> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-02-26target: Add counters for ABORT_TASK success + failureNicholas Bellinger1-0/+2
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>
2017-02-20target: Delete tmr from list before processingBart Van Assche1-6/+1
This patch does an explicit list_del_init(tmr->tmr_list) in core_tmr_drain_tmr_list() before starting processing of outstanding TMRs to abort, instead of explicitly checking which TMR descriptor matches the caller. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Christoph Hellwig <hch@lst.de> Cc: David Disseldorp <ddiss@suse.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-02-09target: Make core_tmr_abort_task() consider all commandsBart Van Assche1-5/+3
It is possible that two commands with the same tag are present on sess_cmd_list because commands are removed from sess_cmd_list after a response has been sent to the initiator. Hence continue searching through sess_cmd_list even if a matching tag has already been found. 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: Himanshu Madhani <himanshu.madhani@cavium.com> Cc: Giridhar Malavali <giridhar.malavali@cavium.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-03-05target: Drop incorrect ABORT_TASK put for completed commandsNicholas Bellinger1-1/+0
This patch fixes a recent ABORT_TASK regression associated with commit febe562c, where a left-over target_put_sess_cmd() would still be called when __target_check_io_state() detected a command has already been completed, and explicit ABORT must be avoided. Note commit febe562c dropped the local kref_get_unless_zero() check in core_tmr_abort_task(), but did not drop this extra corresponding target_put_sess_cmd() in the failure path. So go ahead and drop this now bogus target_put_sess_cmd(), and avoid this potential use-after-free. Reported-by: Dan Lane <dracodan@gmail.com> Cc: Quinn Tran <quinn.tran@qlogic.com> Cc: Himanshu Madhani <himanshu.madhani@qlogic.com> Cc: Sagi Grimberg <sagig@mellanox.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.de> Cc: Andy Grover <agrover@redhat.com> Cc: Mike Christie <mchristi@redhat.com> Cc: stable@vger.kernel.org # 3.14+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-02-05target: Fix remote-port TMR ABORT + se_cmd fabric stopNicholas Bellinger1-16/+38
To address the bug where fabric driver level shutdown of se_cmd occurs at the same time when TMR CMD_T_ABORTED is happening resulting in a -1 ->cmd_kref, this patch adds a CMD_T_FABRIC_STOP bit that is used to determine when TMR + driver I_T nexus shutdown is happening concurrently. It changes target_sess_cmd_list_set_waiting() to obtain se_cmd->cmd_kref + set CMD_T_FABRIC_STOP, and drop local reference in target_wait_for_sess_cmds() and invoke extra target_put_sess_cmd() during Task Aborted Status (TAS) when necessary. Also, it adds a new target_wait_free_cmd() wrapper around transport_wait_for_tasks() for the special case within transport_generic_free_cmd() to set CMD_T_FABRIC_STOP, and is now aware of CMD_T_ABORTED + CMD_T_TAS status bits to know when an extra transport_put_cmd() during TAS is required. Note transport_generic_free_cmd() is expected to block on cmd->cmd_wait_comp in order to follow what iscsi-target expects during iscsi_conn context se_cmd shutdown. Cc: Quinn Tran <quinn.tran@qlogic.com> Cc: Himanshu Madhani <himanshu.madhani@qlogic.com> Cc: Sagi Grimberg <sagig@mellanox.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.de> Cc: Andy Grover <agrover@redhat.com> Cc: Mike Christie <mchristi@redhat.com> Cc: stable@vger.kernel.org # 3.10+ Signed-off-by: Nicholas Bellinger <nab@daterainc.com>
2016-02-03target: Fix TAS handling for multi-session se_node_aclsNicholas Bellinger1-7/+9
This patch fixes a bug in TMR task aborted status (TAS) handling when multiple sessions are connected to the same target WWPN endpoint and se_node_acl descriptor, resulting in TASK_ABORTED status to not be generated for aborted se_cmds on the remote port. This is due to core_tmr_handle_tas_abort() incorrectly comparing se_node_acl instead of se_session, for which the multi-session case is expected to be sharing the same se_node_acl. Instead, go ahead and update core_tmr_handle_tas_abort() to compare tmr_sess + cmd->se_sess in order to determine if the LUN_RESET was received on a different I_T nexus, and TASK_ABORTED status response needs to be generated. Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Quinn Tran <quinn.tran@qlogic.com> Cc: Himanshu Madhani <himanshu.madhani@qlogic.com> Cc: Sagi Grimberg <sagig@mellanox.com> Cc: Hannes Reinecke <hare@suse.de> Cc: Andy Grover <agrover@redhat.com> Cc: Mike Christie <mchristi@redhat.com> Cc: stable@vger.kernel.org # 3.10+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-02-03target: Fix LUN_RESET active TMR descriptor handlingNicholas Bellinger1-1/+21
This patch fixes a NULL pointer se_cmd->cmd_kref < 0 refcount bug during TMR LUN_RESET with active TMRs, triggered during se_cmd + se_tmr_req descriptor shutdown + release via core_tmr_drain_tmr_list(). To address this bug, go ahead and obtain a local kref_get_unless_zero(&se_cmd->cmd_kref) for active I/O to set CMD_T_ABORTED, and transport_wait_for_tasks() followed by the final target_put_sess_cmd() to drop the local ->cmd_kref. Also add two new checks within target_tmr_work() to avoid CMD_T_ABORTED -> TFO->queue_tm_rsp() callbacks ahead of invoking the backend -> fabric put in transport_cmd_check_stop_to_fabric(). For good measure, also change core_tmr_release_req() to use list_del_init() ahead of se_tmr_req memory free. Reviewed-by: Quinn Tran <quinn.tran@qlogic.com> Cc: Himanshu Madhani <himanshu.madhani@qlogic.com> Cc: Sagi Grimberg <sagig@mellanox.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.de> Cc: Andy Grover <agrover@redhat.com> Cc: Mike Christie <mchristi@redhat.com> Cc: stable@vger.kernel.org # 3.10+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-02-03target: Fix LUN_RESET active I/O handling for ACK_KREFNicholas Bellinger1-23/+46
This patch fixes a NULL pointer se_cmd->cmd_kref < 0 refcount bug during TMR LUN_RESET with active se_cmd I/O, that can be triggered during se_cmd descriptor shutdown + release via core_tmr_drain_state_list() code. To address this bug, add common __target_check_io_state() helper for ABORT_TASK + LUN_RESET w/ CMD_T_COMPLETE checking, and set CMD_T_ABORTED + obtain ->cmd_kref for both cases ahead of last target_put_sess_cmd() after TFO->aborted_task() -> transport_cmd_finish_abort() callback has completed. It also introduces SCF_ACK_KREF to determine when transport_cmd_finish_abort() needs to drop the second extra reference, ahead of calling target_put_sess_cmd() for the final kref_put(&se_cmd->cmd_kref). It also updates transport_cmd_check_stop() to avoid holding se_cmd->t_state_lock while dropping se_cmd device state via target_remove_from_state_list(), now that core_tmr_drain_state_list() is holding the se_device lock while checking se_cmd state from within TMR logic. Finally, move transport_put_cmd() release of SGL + TMR + extended CDB memory into target_free_cmd_mem() in order to avoid potential resource leaks in TMR ABORT_TASK + LUN_RESET code-paths. Also update target_release_cmd_kref() accordingly. Reviewed-by: Quinn Tran <quinn.tran@qlogic.com> Cc: Himanshu Madhani <himanshu.madhani@qlogic.com> Cc: Sagi Grimberg <sagig@mellanox.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.de> Cc: Andy Grover <agrover@redhat.com> Cc: Mike Christie <mchristi@redhat.com> Cc: stable@vger.kernel.org # 3.10+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-01-20Merge branch 'for-next' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending Pull SCSI target updates from Nicholas Bellinger: "The highlights this round include: - Introduce configfs support for unlocked configfs_depend_item() (krzysztof + andrezej) - Conversion of usb-gadget target driver to new function registration interface (andrzej + sebastian) - Enable qla2xxx FC target mode support for Extended Logins (himansu + giridhar) - Enable qla2xxx FC target mode support for Exchange Offload (himansu + giridhar) - Add qla2xxx FC target mode irq affinity notification + selective command queuing. (quinn + himanshu) - Fix iscsi-target deadlock in se_node_acl configfs deletion (sagi + nab) - Convert se_node_acl configfs deletion + se_node_acl->queue_depth to proper se_session->sess_kref + target_get_session() usage. (hch + sagi + nab) - Fix long-standing race between se_node_acl->acl_kref get and get_initiator_node_acl() lookup. (hch + nab) - Fix target/user block-size handling, and make sure netlink reaches all network namespaces (sheng + andy) Note there is an outstanding bug-fix series for remote I_T nexus port TMR LUN_RESET has been posted and still being tested, and will likely become post -rc1 material at this point" * 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (56 commits) scsi: qla2xxxx: avoid type mismatch in comparison target/user: Make sure netlink would reach all network namespaces target: Obtain se_node_acl->acl_kref during get_initiator_node_acl target: Convert ACL change queue_depth se_session reference usage iscsi-target: Fix potential dead-lock during node acl delete ib_srpt: Convert acl lookup to modern get_initiator_node_acl usage tcm_fc: Convert acl lookup to modern get_initiator_node_acl usage tcm_fc: Wait for command completion before freeing a session target: Fix a memory leak in target_dev_lba_map_store() target: Support aborting tasks with a 64-bit tag usb/gadget: Remove set-but-not-used variables target: Remove an unused variable target: Fix indentation in target_core_configfs.c target/user: Allow user to set block size before enabling device iser-target: Fix non negative ERR_PTR isert_device_get usage target/fcoe: Add tag support to tcm_fc qla2xxx: Check for online flag instead of active reset when transmitting responses qla2xxx: Set all queues to 4k qla2xxx: Disable ZIO at start time. qla2xxx: Move atioq to a different lock to reduce lock contention ...
2016-01-06target: Fix spelling + remove set-but-not-used variablesBart Van Assche1-1/+1
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Reviewed-by: Andy Grover <agrover@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-11-28target: Invoke release_cmd() callback without holding a spinlockBart Van Assche1-1/+6
This patch fixes the following kernel warning because it avoids that IRQs are disabled while ft_release_cmd() is invoked (fc_seq_set_resp() invokes spin_unlock_bh()): WARNING: CPU: 3 PID: 117 at kernel/softirq.c:150 __local_bh_enable_ip+0xaa/0x110() Call Trace: [<ffffffff814f71eb>] dump_stack+0x4f/0x7b [<ffffffff8105e56a>] warn_slowpath_common+0x8a/0xc0 [<ffffffff8105e65a>] warn_slowpath_null+0x1a/0x20 [<ffffffff81062b2a>] __local_bh_enable_ip+0xaa/0x110 [<ffffffff814ff229>] _raw_spin_unlock_bh+0x39/0x40 [<ffffffffa03a7f94>] fc_seq_set_resp+0xe4/0x100 [libfc] [<ffffffffa02e604a>] ft_free_cmd+0x4a/0x90 [tcm_fc] [<ffffffffa02e6972>] ft_release_cmd+0x12/0x20 [tcm_fc] [<ffffffffa042bd66>] target_release_cmd_kref+0x56/0x90 [target_core_mod] [<ffffffffa042caf0>] target_put_sess_cmd+0xc0/0x110 [target_core_mod] [<ffffffffa042cb81>] transport_release_cmd+0x41/0x70 [target_core_mod] [<ffffffffa042d975>] transport_generic_free_cmd+0x35/0x420 [target_core_mod] Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Acked-by: Joern Engel <joern@logfs.org> Reviewed-by: Andy Grover <agrover@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.de> Cc: Sagi Grimberg <sagig@mellanox.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-07-04Merge branch 'for-next' of ↵Linus Torvalds1-12/+12
git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending Pull SCSI target updates from Nicholas Bellinger: "It's been a busy development cycle for target-core in a number of different areas. The fabric API usage for se_node_acl allocation is now within target-core code, dropping the external API callers for all fabric drivers tree-wide. There is a new conversion to RCU hlists for se_node_acl and se_portal_group LUN mappings, that turns fast-past LUN lookup into a completely lockless code-path. It also removes the original hard-coded limitation of 256 LUNs per fabric endpoint. The configfs attributes for backends can now be shared between core and driver code, allowing existing drivers to use common code while still allowing flexibility for new backend provided attributes. The highlights include: - Merge sbc_verify_dif_* into common code (sagi) - Remove iscsi-target support for obsolete IFMarker/OFMarker (Christophe Vu-Brugier) - Add bidi support in target/user backend (ilias + vangelis + agover) - Move se_node_acl allocation into target-core code (hch) - Add crc_t10dif_update common helper (akinobu + mkp) - Handle target-core odd SGL mapping for data transfer memory (akinobu) - Move transport ID handling into target-core (hch) - Move task tag into struct se_cmd + support 64-bit tags (bart) - Convert se_node_acl->device_list[] to RCU hlist (nab + hch + paulmck) - Convert se_portal_group->tpg_lun_list[] to RCU hlist (nab + hch + paulmck) - Simplify target backend driver registration (hch) - Consolidate + simplify target backend attribute implementations (hch + nab) - Subsume se_port + t10_alua_tg_pt_gp_member into se_lun (hch) - Drop lun_sep_lock for se_lun->lun_se_dev RCU usage (hch + nab) - Drop unnecessary core_tpg_register TFO parameter (nab) - Use 64-bit LUNs tree-wide (hannes) - Drop left-over TARGET_MAX_LUNS_PER_TRANSPORT limit (hannes)" * 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (76 commits) target: Bump core version to v5.0 target: remove target_core_configfs.h target: remove unused TARGET_CORE_CONFIG_ROOT define target: consolidate version defines target: implement WRITE_SAME with UNMAP bit using ->execute_unmap target: simplify UNMAP handling target: replace se_cmd->execute_rw with a protocol_data field target/user: Fix inconsistent kmap_atomic/kunmap_atomic target: Send UA when changing LUN inventory target: Send UA upon LUN RESET tmr completion target: Send UA on ALUA target port group change target: Convert se_lun->lun_deve_lock to normal spinlock target: use 'se_dev_entry' when allocating UAs target: Remove 'ua_nacl' pointer from se_ua structure target_core_alua: Correct UA handling when switching states xen-scsiback: Fix compile warning for 64-bit LUN target: Remove TARGET_MAX_LUNS_PER_TRANSPORT target: use 64-bit LUNs target: Drop duplicate + unused se_dev_check_wce target: Drop unnecessary core_tpg_register TFO parameter ...
2015-06-02target: Minimize SCSI header #include directivesBart Van Assche1-2/+0
Only include SCSI initiator header files in target code that needs these header files, namely the SCSI pass-through code and the tcm_loop driver. Change SCSI_SENSE_BUFFERSIZE into TRANSPORT_SENSE_BUFFER in target code because the former is intended for initiator code and the latter for target code. With this patch the only initiator include directives in target code that remain are as follows: $ git grep -nHE 'include .scsi/(scsi.h|scsi_host.h|scsi_device.h|scsi_cmnd.h)' drivers/target drivers/infiniband/ulp/{isert,srpt} drivers/usb/gadget/legacy/tcm_*.[ch] drivers/{vhost,xen} include/{target,trace/events/target.h} drivers/target/loopback/tcm_loop.c:29:#include <scsi/scsi.h> drivers/target/loopback/tcm_loop.c:31:#include <scsi/scsi_host.h> drivers/target/loopback/tcm_loop.c:32:#include <scsi/scsi_device.h> drivers/target/loopback/tcm_loop.c:33:#include <scsi/scsi_cmnd.h> drivers/target/target_core_pscsi.c:39:#include <scsi/scsi_device.h> drivers/target/target_core_pscsi.c:40:#include <scsi/scsi_host.h> drivers/xen/xen-scsiback.c:52:#include <scsi/scsi_host.h> /* SG_ALL */ Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-05-30target: target_core_configfs.h is not needed in fabric driversChristoph Hellwig1-1/+0
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-05-30target: Move task tag into struct se_cmd + support 64-bit tagsBart Van Assche1-10/+11
Simplify target core and target drivers by storing the task tag a.k.a. command identifier inside struct se_cmd. For several transports (e.g. SRP) tags are 64 bits wide. Hence add support for 64-bit tags. (Fix core_tmr_abort_task conversion spec warnings - nab) (Fix up usb-gadget to use 16-bit tags - HCH + bart) Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Andy Grover <agrover@redhat.com> Cc: Sagi Grimberg <sagig@mellanox.com> Cc: <qla2xxx-upstream@qlogic.com> Cc: Felipe Balbi <balbi@ti.com> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Juergen Gross <jgross@suse.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-05-30target: Remove first argument of target_{get,put}_sess_cmd()Bart Van Assche1-1/+1
The first argument of these two functions is always identical to se_cmd->se_sess. Hence remove the first argument. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Andy Grover <agrover@redhat.com> Cc: <qla2xxx-upstream@qlogic.com> Cc: Felipe Balbi <balbi@ti.com> Cc: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-04-15target: Make core_tmr_abort_task() skip TMFsBart Van Assche1-2/+2
The loop in core_tmr_abort_task() iterates over sess_cmd_list. That list is a list of regular commands and task management functions (TMFs). Skip TMFs in this loop instead of letting the target drivers filter out TMFs in their get_task_tag() callback function. (Drop bogus check removal in tcm_qla2xxx_get_task_tag - nab) Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Andy Grover <agrover@redhat.com> Cc: <qla2xxx-upstream@qlogic.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-10-01target: simplify core_tmr_abort_taskJoern Engel1-3/+2
list_for_each_entry_safe is necessary if list objects are deleted from the list while traversing it. Not the case here, so we can use the base list_for_each_entry variant. Signed-off-by: Joern Engel <joern@logfs.org> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-10-01target: simplify core_tmr_release_req()Joern Engel1-12/+7
And while at it, do minimal coding style fixes in the area. Signed-off-by: Joern Engel <joern@logfs.org> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-04-11target: Add check to prevent Abort Task from aborting itselfAlex Leung1-0/+5
This patch addresses an issue that occurs when an ABTS is received for an se_cmd that completes just before the sess_cmd_list is searched in core_tmr_abort_task(). When the sess_cmd_list is searched, since the ABTS and the FCP_CMND being aborted (that just completed) both have the same OXID, TFO->get_task_tag(TMR) returns a value that matches tmr->ref_task_tag (from TFO->get_task_tag(FCP_CMND)), and the Abort Task tries to abort itself. When this occurs, transport_wait_for_tasks() hangs forever since the TMR is waiting for itself to finish. This patch adds a check to core_tmr_abort_task() to make sure the TMR does not attempt to abort itself. Signed-off-by: Alex Leung <alex.leung@emulex.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-04-07target: Fix Task Aborted Status (TAS) handlingAlex Leung1-12/+6
This patch addresses three of long standing issues wrt to Task Aborted Status (TAS) handling. The first is the incorrect assumption in core_tmr_handle_tas_abort() that TASK_ABORTED status is sent for the task referenced by TMR ABORT_TASK, and sending TASK_ABORTED status for TMR LUN_RESET on the same nexus the LUN_RESET was received. The second is to ensure the lun reference count is dropped within transport_cmd_finish_abort() by calling transport_lun_remove_cmd() before invoking transport_cmd_check_stop_to_fabric(). The last is to fix the delayed TAS handling to allow outstanding WRITEs to complete before sending the TASK_ABORTED status. This includes changing transport_check_aborted_status() to avoid processing when SCF_SEND_DELAYED_TAS has not be set, and updating transport_send_task_abort() to drop the SCF_SENT_DELAYED_TAS check. Signed-off-by: Alex Leung <amleung21@yahoo.com> Cc: Alex Leung <amleung21@yahoo.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2013-11-13target: Convert se_device statistics to atomic_long_tNicholas Bellinger1-3/+1
This patch converts the handful of se_device statistics to type atomic_long_t, instead of using se_device->stats_lock when incrementing these values. More importantly, go ahead and drop the spinlock usage within transport_lookup_cmd_lun() fast-path code. Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2013-09-10target: Update copyright ownership/year information to 2013Nicholas Bellinger1-1/+1
Update copyright ownership/year information for target-core, loopback, iscsi-target, tcm_qla2xx, vhost and iser-target. Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2013-06-20target: Remove legacy t_fe_count + avoid t_state_lock access in ↵Nicholas Bellinger1-10/+2
transport_put_cmd This patch removes legacy se_cmd->t_fe_count usage in order to avoid se_cmd->t_state_lock access within transport_put_cmd() during normal fast path se_cmd descriptor release. Also drop the left-over parameter usage within core_tmr_handle_tas_abort() Cc: Christoph Hellwig <hch@lst.de> Cc: Roland Dreier <roland@kernel.org> Cc: Kent Overstreet <koverstreet@google.com> Cc: Or Gerlitz <ogerlitz@mellanox.com> Cc: Moussa Ba <moussaba@micron.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2013-02-13target: Remove useless if statementRoland Dreier1-12/+0
We do the same thing no matter which way the test goes, so just remove the test and do what we're going to do. The debug messages printed the wrong value of CMD_T_ACTIVE and don't seem particularly useful, remove them too. Signed-off-by: Roland Dreier <roland@purestorage.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2012-11-27target: Update copyright information to 2012Nicholas Bellinger1-2/+1
v2: Use correct target_core_stat.c 2006 copyright year v3: Drop extra unnessary legal verbage from header (hch) Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2012-11-06target: kill struct se_subsystem_devChristoph Hellwig1-3/+3
Simplify the code a lot by killing the superflous struct se_subsystem_dev. Instead se_device is allocated early on by the backend driver, which allocates it as part of its own per-device structure, borrowing the scheme that is for example used for inode allocation. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2012-11-01target: Fix incorrect usage of nested IRQ spinlocks in ABORT_TASK pathSteve Hodgson1-3/+3
This patch changes core_tmr_abort_task() to use spin_lock -> spin_unlock around se_cmd->t_state_lock while spin_lock_irqsave is held via se_sess->sess_cmd_lock. Signed-off-by: Steve Hodgson <steve@purestorage.com> Signed-off-by: Roland Dreier <roland@purestorage.com> Cc: stable@vger.kernel.org Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2012-07-16target: replace the processing thread with a TMR work queueChristoph Hellwig1-53/+1
The last functionality of the target processing thread is offloading possibly long running task management requests from the submitter context. To keep TMR semantics the same we need a single threaded ordered queue, which can be provided by a per-device workqueue with the right flags. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>