linux/drivers/target, branch v4.11

tcmu: Skip Data-Out blocks before gathering Data-In buffer for BIDI case

2017-04-02T23:18:51Z

For the bidirectional case, the Data-Out buffer blocks will always at the head of the tcmu_cmd's bitmap, and before gathering the Data-In buffer, first of all it should skip the Data-Out ones, or the device supporting BIDI commands won't work. Fixed: 26418649eead ("target/user: Introduce data_bitmap, replace data_length/data_head/data_tail") Reported-by: Ilias Tsitsimpis Tested-by: Ilias Tsitsimpis Signed-off-by: Xiubo Li Cc: stable@vger.kernel.org # 4.6+ Signed-off-by: Nicholas Bellinger

iscsi-target: Drop work-around for legacy GlobalSAN initiator

2017-04-02T21:10:16Z

Once upon a time back in 2009, a work-around was added to support the GlobalSAN iSCSI initiator v3.3 for MacOSX, which during login did not propose nor respond to MaxBurstLength, FirstBurstLength, DefaultTime2Wait and DefaultTime2Retain keys. The work-around in iscsi_check_proposer_for_optional_reply() allowed the missing keys to be proposed, but did not require waiting for a response before moving to full feature phase operation. This allowed GlobalSAN v3.3 to work out-of-the box, and for many years we didn't run into login interopt issues with any other initiators.. Until recently, when Martin tried a QLogic 57840S iSCSI Offload HBA on Windows 2016 which completed login, but subsequently failed with: Got unknown iSCSI OpCode: 0x43 The issue was QLogic MSFT side did not propose DefaultTime2Wait + DefaultTime2Retain, so LIO proposes them itself, and immediately transitions to full feature phase because of the GlobalSAN hack. However, the QLogic MSFT side still attempts to respond to DefaultTime2Retain + DefaultTime2Wait, even though LIO has set ISCSI_FLAG_LOGIN_NEXT_STAGE3 + ISCSI_FLAG_LOGIN_TRANSIT in last login response. So while the QLogic MSFT side should have been proposing these two keys to start, it was doing the correct thing per RFC-3720 attempting to respond to proposed keys before transitioning to full feature phase. All that said, recent versions of GlobalSAN iSCSI (v5.3.0.541) does correctly propose the four keys during login, making the original work-around moot. So in order to allow QLogic MSFT to run unmodified as-is, go ahead and drop this long standing work-around. Reported-by: Martin Svec Cc: Martin Svec Cc: Himanshu Madhani Cc: Arun Easi Cc: stable@vger.kernel.org # 3.1+ Signed-off-by: Nicholas Bellinger

target: Fix ALUA transition state race between multiple initiators

2017-03-31T06:12:40Z

Multiple threads could be writing to alua_access_state at the same time, or there could be multiple STPGs in flight (different initiators sending them or one initiator sending them to different ports), or a combo of both and the core_alua_do_transition_tg_pt calls will race with each other. Because from the last patches we no longer delay running core_alua_do_transition_tg_pt_work, there does not seem to be any point in running that in a workqueue. And, we always wait for it to complete one way or another, so we can sleep in this code path. So, this patch made over target-pending just adds a mutex and does the work core_alua_do_transition_tg_pt_work was doing in core_alua_do_transition_tg_pt. There is also no need to use an atomic for the tg_pt_gp_alua_access_state. In core_alua_do_transition_tg_pt we will test and set it under the transition mutex. And, it is a int/32 bits so in the other places where it is read, we will never see it partially updated. Signed-off-by: Mike Christie Signed-off-by: Nicholas Bellinger

iscsi-target: Propigate queue_data_in + queue_status errors

2017-03-31T03:34:58Z

This patch changes iscsi-target to propagate iscsit_transport ->iscsit_queue_data_in() and ->iscsit_queue_status() callback errors, back up into target-core. This allows target-core to retry failed iscsit_transport callbacks using internal queue-full logic. Reported-by: Potnuri Bharat Teja Reviewed-by: Potnuri Bharat Teja Tested-by: Potnuri Bharat Teja Cc: Potnuri Bharat Teja Reported-by: Steve Wise Cc: Steve Wise Cc: Sagi Grimberg Signed-off-by: Nicholas Bellinger

target: Fix unknown fabric callback queue-full errors

2017-03-31T03:34:31Z

This patch fixes a set of queue-full response handling bugs, where outgoing responses are leaked when a fabric driver is propagating non -EAGAIN or -ENOMEM errors to target-core. It introduces TRANSPORT_COMPLETE_QF_ERR state used to signal when CHECK_CONDITION status should be generated, when fabric driver ->write_pending(), ->queue_data_in(), or ->queue_status() callbacks fail with non -EAGAIN or -ENOMEM errors, and data-transfer should not be retried. Note all fabric driver -EAGAIN and -ENOMEM errors are still retried indefinately with associated data-transfer callbacks, following existing queue-full logic. Also fix two missing ->queue_status() queue-full cases related to CMD_T_ABORTED w/ TAS status handling. Reported-by: Potnuri Bharat Teja Reviewed-by: Potnuri Bharat Teja Tested-by: Potnuri Bharat Teja Cc: Potnuri Bharat Teja Reported-by: Steve Wise Cc: Steve Wise Cc: Sagi Grimberg Signed-off-by: Nicholas Bellinger

tcmu: Fix wrongly calculating of the base_command_size

2017-03-30T08:36:53Z

The t_data_nents and t_bidi_data_nents are the numbers of the segments, but it couldn't be sure the block size equals to size of the segment. For the worst case, all the blocks are discontiguous and there will need the same number of iovecs, that's to say: blocks == iovs. So here just set the number of iovs to block count needed by tcmu cmd. Tested-by: Ilias Tsitsimpis Reviewed-by: Mike Christie Signed-off-by: Xiubo Li Cc: stable@vger.kernel.org # 3.18+ Signed-off-by: Nicholas Bellinger

tcmu: Fix possible overwrite of t_data_sg's last iov[]

2017-03-30T08:36:52Z

If there has BIDI data, its first iov[] will overwrite the last iov[] for se_cmd->t_data_sg. To fix this, we can just increase the iov pointer, but this may introuduce a new memory leakage bug: If the se_cmd->data_length and se_cmd->t_bidi_data_sg->length are all not aligned up to the DATA_BLOCK_SIZE, the actual length needed maybe larger than just sum of them. So, this could be avoided by rounding all the data lengthes up to DATA_BLOCK_SIZE. Reviewed-by: Mike Christie Tested-by: Ilias Tsitsimpis Reviewed-by: Bryant G. Ly Signed-off-by: Xiubo Li Cc: stable@vger.kernel.org # 3.18+ Signed-off-by: Nicholas Bellinger

target: Avoid mappedlun symlink creation during lun shutdown

2017-03-30T08:36:52Z

This patch closes a race between se_lun deletion during configfs unlink in target_fabric_port_unlink() -> core_dev_del_lun() -> core_tpg_remove_lun(), when transport_clear_lun_ref() blocks waiting for percpu_ref RCU grace period to finish, but a new NodeACL mappedlun is added before the RCU grace period has completed. This can happen in target_fabric_mappedlun_link() because it only checks for se_lun->lun_se_dev, which is not cleared until after transport_clear_lun_ref() percpu_ref RCU grace period finishes. This bug originally manifested as NULL pointer dereference OOPsen in target_stat_scsi_att_intr_port_show_attr_dev() on v4.1.y code, because it dereferences lun->lun_se_dev without a explicit NULL pointer check. In post v4.1 code with target-core RCU conversion, the code in target_stat_scsi_att_intr_port_show_attr_dev() no longer uses se_lun->lun_se_dev, but the same race still exists. To address the bug, go ahead and set se_lun>lun_shutdown as early as possible in core_tpg_remove_lun(), and ensure new NodeACL mappedlun creation in target_fabric_mappedlun_link() fails during se_lun shutdown. Reported-by: James Shen Cc: James Shen Tested-by: James Shen Cc: stable@vger.kernel.org # 3.10+ Signed-off-by: Nicholas Bellinger

iscsi-target: Fix TMR reference leak during session shutdown

2017-03-30T08:36:51Z

This patch fixes a iscsi-target specific TMR reference leak during session shutdown, that could occur when a TMR was quiesced before the hand-off back to iscsi-target code via transport_cmd_check_stop_to_fabric(). The reference leak happens because iscsit_free_cmd() was incorrectly skipping the final target_put_sess_cmd() for TMRs when transport_generic_free_cmd() returned zero because the se_cmd->cmd_kref did not reach zero, due to the missing se_cmd assignment in original code. The result was iscsi_cmd and it's associated se_cmd memory would be freed once se_sess->sess_cmd_map where released, but the associated se_tmr_req was leaked and remained part of se_device->dev_tmr_list. This bug would manfiest itself as kernel paging request OOPsen in core_tmr_lun_reset(), when a left-over se_tmr_req attempted to dereference it's se_cmd pointer that had already been released during normal session shutdown. To address this bug, go ahead and treat ISCSI_OP_SCSI_CMD and ISCSI_OP_SCSI_TMFUNC the same when there is an extra se_cmd->cmd_kref to drop in iscsit_free_cmd(), and use op_scsi to signal __iscsit_free_cmd() when the former needs to clear any further iscsi related I/O state. Reported-by: Rob Millner Cc: Rob Millner Reported-by: Chu Yuan Lin Cc: Chu Yuan Lin Tested-by: Chu Yuan Lin Cc: stable@vger.kernel.org # 3.10+ Signed-off-by: Nicholas Bellinger

tcmu: Allow cmd_time_out to be set to zero (disabled)

2017-03-30T08:36:44Z

The new cmd_time_out configfs attribute for TCMU is allowed to be disabled, so go ahead and drop the tcmu_cmd_time_out_store() check. Reported-by: Mike Christie Signed-off-by: Nicholas Bellinger