user/sven/linux.git/include/target, branch v4.12.13

iscsi-target: Fix iscsi_np reset hung task during parallel delete

2017-08-16T20:46:51Z

commit 978d13d60c34818a41fc35962602bdfa5c03f214 upstream. 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] [] schedule+0x32/0x80 [ 6726.170156] [] schedule_timeout+0x214/0x290 [ 6726.176030] [] ? __send_signal+0x52/0x4a0 [ 6726.181728] [] wait_for_completion+0x96/0x100 [ 6726.187774] [] ? wake_up_state+0x10/0x10 [ 6726.193395] [] iscsit_reset_np_thread+0x62/0xe0 [iscsi_target_mod] [ 6726.201278] [] iscsit_tpg_disable_portal_group+0x96/0x190 [iscsi_target_mod] [ 6726.210033] [] lio_target_tpg_store_enable+0x4f/0xc0 [iscsi_target_mod] [ 6726.218351] [] configfs_write_file+0xaa/0x110 [ 6726.224392] [] vfs_write+0xa4/0x1b0 [ 6726.229576] [] SyS_write+0x41/0xb0 [ 6726.234659] [] 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 Tested-by: Gary Guo Cc: Mike Christie Cc: Hannes Reinecke Signed-off-by: Nicholas Bellinger Signed-off-by: Greg Kroah-Hartman

iscsi-target: Add login_keys_workaround attribute for non RFC initiators

2017-07-27T22:10:08Z

commit 138d351eefb727ab9e41a3dc5f112ceb4f6e59f2 upstream. This patch re-introduces part of a long standing login workaround that was recently dropped by: commit 1c99de981f30b3e7868b8d20ce5479fa1c0fea46 Author: Nicholas Bellinger Date: Sun Apr 2 13:36:44 2017 -0700 iscsi-target: Drop work-around for legacy GlobalSAN initiator Namely, the workaround for FirstBurstLength ended up being required by Mellanox Flexboot PXE boot ROMs as reported by Robert. So this patch re-adds the work-around for FirstBurstLength within iscsi_check_proposer_for_optional_reply(), and makes the key optional to respond when the initiator does not propose, nor respond to it. Also as requested by Arun, this patch introduces a new TPG attribute named 'login_keys_workaround' that controls the use of both the FirstBurstLength workaround, as well as the two other existing workarounds for gPXE iSCSI boot client. By default, the workaround is enabled with login_keys_workaround=1, since Mellanox FlexBoot requires it, and Arun has verified the Qlogic MSFT initiator already proposes FirstBurstLength, so it's uneffected by this re-adding this part of the original work-around. Reported-by: Robert LeBlanc Cc: Robert LeBlanc Reviewed-by: Arun Easi Signed-off-by: Nicholas Bellinger Signed-off-by: Greg Kroah-Hartman

iscsi-target: Fix initial login PDU asynchronous socket close OOPs

2017-05-31T22:12:31Z

This patch fixes a OOPs originally introduced by: commit bb048357dad6d604520c91586334c9c230366a14 Author: Nicholas Bellinger Date: Thu Sep 5 14:54:04 2013 -0700 iscsi-target: Add sk->sk_state_change to cleanup after TCP failure which would trigger a NULL pointer dereference when a TCP connection was closed asynchronously via iscsi_target_sk_state_change(), but only when the initial PDU processing in iscsi_target_do_login() from iscsi_np process context was blocked waiting for backend I/O to complete. To address this issue, this patch makes the following changes. First, it introduces some common helper functions used for checking socket closing state, checking login_flags, and atomically checking socket closing state + setting login_flags. Second, it introduces a LOGIN_FLAGS_INITIAL_PDU bit to know when a TCP connection has dropped via iscsi_target_sk_state_change(), but the initial PDU processing within iscsi_target_do_login() in iscsi_np context is still running. For this case, it sets LOGIN_FLAGS_CLOSED, but doesn't invoke schedule_delayed_work(). The original NULL pointer dereference case reported by MNC is now handled by iscsi_target_do_login() doing a iscsi_target_sk_check_close() before transitioning to FFP to determine when the socket has already closed, or iscsi_target_start_negotiation() if the login needs to exchange more PDUs (eg: iscsi_target_do_login returned 0) but the socket has closed. For both of these cases, the cleanup up of remaining connection resources will occur in iscsi_target_start_negotiation() from iscsi_np process context once the failure is detected. Finally, to handle to case where iscsi_target_sk_state_change() is called after the initial PDU procesing is complete, it now invokes conn->login_work -> iscsi_target_do_login_rx() to perform cleanup once existing iscsi_target_sk_check_close() checks detect connection failure. For this case, the cleanup of remaining connection resources will occur in iscsi_target_do_login_rx() from delayed workqueue process context once the failure is detected. Reported-by: Mike Christie Reviewed-by: Mike Christie Tested-by: Mike Christie Cc: Mike Christie Reported-by: Hannes Reinecke Cc: Hannes Reinecke Cc: Sagi Grimberg Cc: Varun Prakash Cc: # v3.12+ Signed-off-by: Nicholas Bellinger

target/user: PGR Support

2017-05-02T05:21:45Z

This adds initial PGR support for just TCMU, since tcmu doesn't have the necessary IT_NEXUS info to process PGR in userspace, so have those commands be processed in kernel. HA support is not available yet, we will work on it if this patch is acceptable. Signed-off-by: Bryant G. Ly Signed-off-by: Nicholas Bellinger

tcm: make pi data verification configurable

2017-05-02T05:20:58Z

Currently ramdisk and fileio always perform PI verification before and after backend IO. This approach is not very flexible. Because some one may want to postpone this work to other layers in IO stack. For example if we want to test blk_integrity_profile testcase: https://github.com/dmonakhov/xfstests/commit/dee408c868861d6b6871dbb3381facee7effdbe4 Signed-off-by: Dmitry Monakhov 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

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

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

target: fix ALUA transition timeout handling

2017-03-18T21:47:28Z

The implicit transition time tells initiators the min time to wait before timing out a transition. We currently schedule the transition to occur in tg_pt_gp_implicit_trans_secs seconds so there is no room for delays. If core_alua_do_transition_tg_pt_work->core_alua_update_tpg_primary_metadata needs to write out info to a remote file, then the initiator can easily time out the operation. Signed-off-by: Mike Christie Signed-off-by: Nicholas Bellinger

target: allow ALUA setup for some passthrough backends

2017-03-18T21:47:25Z

This patch allows passthrough backends to use the core/base LIO ALUA setup and state checks, but still handle the execution of commands. This will allow the target_core_user module to execute STPG and RTPG in userspace, and not have to duplicate the ALUA state checks, path information (needed so we can check if command is executable on specific paths) and setup (rtslib sets/updates the configfs ALUA interface like it does for iblock or file). For STPG, the target_core_user userspace daemon, tcmu-runner will still execute the STPG, and to update the core/base LIO state it will use the existing configfs interface. For RTPG, tcmu-runner will loop over configfs and/or cache the state. Signed-off-by: Mike Christie Signed-off-by: Nicholas Bellinger