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2020-03-26scsi: target: fix hang when multiple threads try to destroy the same iscsi ↵Maurizio Lombardi
session A number of hangs have been reported against the target driver; they are due to the fact that multiple threads may try to destroy the iscsi session at the same time. This may be reproduced for example when a "targetcli iscsi/iqn.../tpg1 disable" command is executed while a logout operation is underway. When this happens, two or more threads may end up sleeping and waiting for iscsit_close_connection() to execute "complete(session_wait_comp)". Only one of the threads will wake up and proceed to destroy the session structure, the remaining threads will hang forever. Note that if the blocked threads are somehow forced to wake up with complete_all(), they will try to free the same iscsi session structure destroyed by the first thread, causing double frees, memory corruptions etc... With this patch, the threads that want to destroy the iscsi session will increase the session refcount and will set the "session_close" flag to 1; then they wait for the driver to close the remaining active connections. When the last connection is closed, iscsit_close_connection() will wake up all the threads and will wait for the session's refcount to reach zero; when this happens, iscsit_close_connection() will destroy the session structure because no one is referencing it anymore. INFO: task targetcli:5971 blocked for more than 120 seconds. Tainted: P OE 4.15.0-72-generic #81~16.04.1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. targetcli D 0 5971 1 0x00000080 Call Trace: __schedule+0x3d6/0x8b0 ? vprintk_func+0x44/0xe0 schedule+0x36/0x80 schedule_timeout+0x1db/0x370 ? __dynamic_pr_debug+0x8a/0xb0 wait_for_completion+0xb4/0x140 ? wake_up_q+0x70/0x70 iscsit_free_session+0x13d/0x1a0 [iscsi_target_mod] iscsit_release_sessions_for_tpg+0x16b/0x1e0 [iscsi_target_mod] iscsit_tpg_disable_portal_group+0xca/0x1c0 [iscsi_target_mod] lio_target_tpg_enable_store+0x66/0xe0 [iscsi_target_mod] configfs_write_file+0xb9/0x120 __vfs_write+0x1b/0x40 vfs_write+0xb8/0x1b0 SyS_write+0x5c/0xe0 do_syscall_64+0x73/0x130 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 Link: https://lore.kernel.org/r/20200313170656.9716-3-mlombard@redhat.com Reported-by: Matt Coleman <mcoleman@datto.com> Tested-by: Matt Coleman <mcoleman@datto.com> Tested-by: Rahul Kundu <rahul.kundu@chelsio.com> Signed-off-by: Maurizio Lombardi <mlombard@redhat.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-03-16scsi: treewide: Consolidate {get,put}_unaligned_[bl]e24() definitionsBart Van Assche
Move the get_unaligned_be24(), get_unaligned_le24() and put_unaligned_le24() definitions from various drivers into include/linux/unaligned/generic.h. Add a put_unaligned_be24() implementation. Link: https://lore.kernel.org/r/20200313203102.16613-4-bvanassche@acm.org Cc: Keith Busch <kbusch@kernel.org> Cc: Sagi Grimberg <sagi@grimberg.me> Cc: Jens Axboe <axboe@fb.com> Cc: Harvey Harrison <harvey.harrison@gmail.com> Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> # For drivers/usb Reviewed-by: Felipe Balbi <balbi@kernel.org> # For drivers/usb/gadget Signed-off-by: Bart Van Assche <bvanassche@acm.org> 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/iscsi: Handle too large immediate data buffers correctlyBart Van Assche
Since target_alloc_sgl() and iscsit_allocate_iovecs() allocate buffer space for se_cmd.data_length bytes and since that number can be smaller than the iSCSI Expected Data Transfer Length (EDTL), ensure that the iSCSI target driver does not attempt to receive more bytes than what fits in the receive buffer. Always receive the full immediate data buffer such that the iSCSI target driver does not attempt to parse immediate data as an iSCSI PDU. Note: the current code base only calls iscsit_get_dataout() if the size of the immediate data buffer does not exceed the buffer size derived from the SCSI CDB. See also target_cmd_size_check(). Cc: Mike Christie <mchristi@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.de> 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>
2019-04-12scsi: 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/iscsi: Rename a function and a function pointerBart Van Assche
Having both a function and a function pointer member with the same name (iscsit_release_cmd) is confusing. Hence rename the function pointer member. 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>
2019-02-04scsi: target/iscsi: Fix spelling of "unsolicited"Bart Van Assche
Change "unsoliticed" into "unsolicited". 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> Cc: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2019-02-04scsi: target/core: Add target_send_busy()Bart Van Assche
Introduce a function that sends the SCSI status "BUSY" back to the initiator. The next patch will add a call to this function in the srpt target driver. 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 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>
2019-02-04scsi: target/core: Remove the write_pending_status() callback functionBart Van Assche
Due to the patch that makes TMF handling synchronous the write_pending_status() callback function is no longer called. Hence remove it. Acked-by: Felipe Balbi <balbi@ti.com> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Reviewed-by: Andy Grover <agrover@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com> Cc: Nicholas Bellinger <nab@linux-iscsi.org> Cc: Mike Christie <mchristi@redhat.com> Cc: Himanshu Madhani <himanshu.madhani@qlogic.com> Cc: Quinn Tran <quinn.tran@qlogic.com> Cc: Saurav Kashyap <saurav.kashyap@qlogic.com> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Juergen Gross <jgross@suse.com> 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: Make ABORT and LUN RESET handling synchronousBart Van Assche
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 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: Simplify the code for aborting SCSI commandsBart Van Assche
Instead of allowing the code that aborts a SCSI command to finish before all iSCSI data frames have been received, make that code wait until all iSCSI data frames have been received. Introduce a new member variable in the target driver template to communicate that information from the iSCSI target driver to the target core. This change allows to leave out the check whether or not it is already safe to send the TASK_ABORTED reply from transport_send_task_abort(). 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: replace fabric_ops.name with fabric_aliasDavid Disseldorp
iscsi_target_mod is the only LIO fabric where fabric_ops.name differs from the fabric_ops.fabric_name string. fabric_ops.name is used when matching target/$fabric ConfigFS create paths, so rename it .fabric_alias and fallback to target/$fabric vs .fabric_name comparison if .fabric_alias isn't initialised. iscsi_target_mod is the only fabric module to set .fabric_alias . All other fabric modules rely on .fabric_name matching and can drop the duplicate string. Signed-off-by: David Disseldorp <ddiss@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-11-28scsi: target: drop unnecessary get_fabric_name() accessor from fabric_opsDavid Disseldorp
All fabrics return a const string. In all cases *except* iSCSI the get_fabric_name() string matches fabric_ops.name. Both fabric_ops.get_fabric_name() and fabric_ops.name are user-facing, with the former being used for PR/ALUA state and the latter for ConfigFS (config/target/$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>
2018-11-28scsi: 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>
2018-10-16scsi: target: use ISCSI_IQN_LEN in iscsi_target_statDavid Disseldorp
Move the ISCSI_IQN_LEN definition up, so that it can be used in more places instead of a hardcoded value. Signed-off-by: David Disseldorp <ddiss@suse.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-08-02scsi: target: add session removal functionMike Christie
This adds a function to remove a session which should be used by drivers that use target_setup_session. The next patches will convert the target drivers to use this new function. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Chris Boot <bootc@bootc.net> Cc: Bryant G. Ly <bryantly@linux.vnet.ibm.com> Cc: Michael Cyr <mikecyr@linux.vnet.ibm.com> Cc: <qla2xxx-upstream@qlogic.com> Cc: Johannes Thumshirn <jth@kernel.org> Cc: Felipe Balbi <balbi@kernel.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Andrzej Pietrasiewicz <andrzej.p@samsung.com> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Juergen Gross <jgross@suse.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-08-02scsi: target: rename target_alloc_sessionMike Christie
Rename target_alloc_session to target_setup_session to avoid confusion with the other transport session allocation function that only allocates the session and because the target_alloc_session does so much more. It allocates the session, sets up the nacl and registers the session. The next patch will then add a remove function to match the setup in this one, so it should make sense for all drivers, except iscsi, to just call those 2 functions to setup and remove a session. iscsi will continue to be the odd driver. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Chris Boot <bootc@bootc.net> Cc: Bryant G. Ly <bryantly@linux.vnet.ibm.com> Cc: Michael Cyr <mikecyr@linux.vnet.ibm.com> Cc: <qla2xxx-upstream@qlogic.com> Cc: Johannes Thumshirn <jth@kernel.org> Cc: Felipe Balbi <balbi@kernel.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Andrzej Pietrasiewicz <andrzej.p@samsung.com> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Juergen Gross <jgross@suse.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-08-02scsi: target: make transport_init_session_tags staticMike Christie
transport_init_session_tags is only called from target_core_transport.c so make it static. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-07-30scsi: target: add helper to check if dev is configuredMike Christie
This just adds a helper function to check if a device is configured and it converts the target users to use it. The next patch will add a backend module user so those types of modules do not have to know the lio core details. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Xiubo Li <xiubli@redhat.com> 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: Remove second argument from fabric_make_tpg()Bart Van Assche
Since most target drivers do not use the second fabric_make_tpg() argument ("group") and since it is trivial to derive the group pointer from the wwn pointer, do not pass the group pointer to fabric_make_tpg(). Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Mike Christie <mchristi@redhat.com> Cc: Felipe Balbi <felipe.balbi@linux.intel.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 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>
2018-07-02scsi: target: Introduce transport_init_session()Bart Van Assche
Other than initializing xcopy_pt_sess.sess_wait_list, 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: 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: Rename transport_init_session() into transport_alloc_session()Bart Van Assche
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Mike Christie <mchristi@redhat.com> Cc: 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>
2018-06-26scsi: target: remove target_find_deviceMike Christie
target_find_device is no longer used, so remove it. Signed-off-by: Mike Christie <mchristi@redhat.com> Tested-by: Xiubo Li <xiubli@redhat.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 ...
2017-11-14Merge tag 'configfs-for-4.15' of git://git.infradead.org/users/hch/configfsLinus Torvalds
Pull configfs updates from Christoph Hellwig: "A couple of configfs cleanups: - proper use of the bool type (Thomas Meyer) - constification of struct config_item_type (Bhumika Goyal)" * tag 'configfs-for-4.15' of git://git.infradead.org/users/hch/configfs: RDMA/cma: make config_item_type const stm class: make config_item_type const ACPI: configfs: make config_item_type const nvmet: make config_item_type const usb: gadget: configfs: make config_item_type const PCI: endpoint: make config_item_type const iio: make function argument and some structures const usb: gadget: make config_item_type structures const dlm: make config_item_type const netconsole: make config_item_type const nullb: make config_item_type const ocfs2/cluster: make config_item_type const target: make config_item_type const configfs: make ci_type field, some pointers and function arguments const configfs: make config_item_type const configfs: Fix bool initialization/comparison
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>
2017-10-19target: make config_item_type constBhumika Goyal
Make these structures const as they are either passed to the functions having the argument as const or stored as a reference in the "ci_type" const field of a config_item structure. Done using Coccinelle. Signed-off-by: Bhumika Goyal <bhumirks@gmail.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-08-06iscsi-target: Fix iscsi_np reset hung task during parallel deleteNicholas Bellinger
This patch fixes a bug associated with iscsit_reset_np_thread() that can occur during parallel configfs rmdir of a single iscsi_np used across multiple iscsi-target instances, that would result in hung task(s) similar to below where configfs rmdir process context was blocked indefinately waiting for iscsi_np->np_restart_comp to finish: [ 6726.112076] INFO: task dcp_proxy_node_:15550 blocked for more than 120 seconds. [ 6726.119440] Tainted: G W O 4.1.26-3321 #2 [ 6726.125045] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 6726.132927] dcp_proxy_node_ D ffff8803f202bc88 0 15550 1 0x00000000 [ 6726.140058] ffff8803f202bc88 ffff88085c64d960 ffff88083b3b1ad0 ffff88087fffeb08 [ 6726.147593] ffff8803f202c000 7fffffffffffffff ffff88083f459c28 ffff88083b3b1ad0 [ 6726.155132] ffff88035373c100 ffff8803f202bca8 ffffffff8168ced2 ffff8803f202bcb8 [ 6726.162667] Call Trace: [ 6726.165150] [<ffffffff8168ced2>] schedule+0x32/0x80 [ 6726.170156] [<ffffffff8168f5b4>] schedule_timeout+0x214/0x290 [ 6726.176030] [<ffffffff810caef2>] ? __send_signal+0x52/0x4a0 [ 6726.181728] [<ffffffff8168d7d6>] wait_for_completion+0x96/0x100 [ 6726.187774] [<ffffffff810e7c80>] ? wake_up_state+0x10/0x10 [ 6726.193395] [<ffffffffa035d6e2>] iscsit_reset_np_thread+0x62/0xe0 [iscsi_target_mod] [ 6726.201278] [<ffffffffa0355d86>] iscsit_tpg_disable_portal_group+0x96/0x190 [iscsi_target_mod] [ 6726.210033] [<ffffffffa0363f7f>] lio_target_tpg_store_enable+0x4f/0xc0 [iscsi_target_mod] [ 6726.218351] [<ffffffff81260c5a>] configfs_write_file+0xaa/0x110 [ 6726.224392] [<ffffffff811ea364>] vfs_write+0xa4/0x1b0 [ 6726.229576] [<ffffffff811eb111>] SyS_write+0x41/0xb0 [ 6726.234659] [<ffffffff8169042e>] system_call_fastpath+0x12/0x71 It would happen because each iscsit_reset_np_thread() sets state to ISCSI_NP_THREAD_RESET, sends SIGINT, and then blocks waiting for completion on iscsi_np->np_restart_comp. However, if iscsi_np was active processing a login request and more than a single iscsit_reset_np_thread() caller to the same iscsi_np was blocked on iscsi_np->np_restart_comp, iscsi_np kthread process context in __iscsi_target_login_thread() would flush pending signals and only perform a single completion of np->np_restart_comp before going back to sleep within transport specific iscsit_transport->iscsi_accept_np code. To address this bug, add a iscsi_np->np_reset_count and update __iscsi_target_login_thread() to keep completing np->np_restart_comp until ->np_reset_count has reached zero. Reported-by: Gary Guo <ghg@datera.io> Tested-by: Gary Guo <ghg@datera.io> Cc: Mike Christie <mchristi@redhat.com> Cc: Hannes Reinecke <hare@suse.de> Cc: stable@vger.kernel.org # 3.10+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>