user/sven/linux.git/drivers/target, branch v4.9.32

target: Re-add check to reject control WRITEs with overflow data

2017-06-14T13:06:00Z

commit 4ff83daa0200affe1894bd33d17bac404e3d78d4 upstream. During v4.3 when the overflow/underflow check was relaxed by commit c72c525022: commit c72c5250224d475614a00c1d7e54a67f77cd3410 Author: Roland Dreier Date: Wed Jul 22 15:08:18 2015 -0700 target: allow underflow/overflow for PR OUT etc. commands to allow underflow/overflow for Windows compliance + FCP, a consequence was to allow control CDBs to process overflow data for iscsi-target with immediate data as well. As per Roland's original change, continue to allow underflow cases for control CDBs to make Windows compliance + FCP happy, but until overflow for control CDBs is supported tree-wide, explicitly reject all control WRITEs with overflow following pre v4.3.y logic. Reported-by: Bart Van Assche Cc: Roland Dreier Signed-off-by: Nicholas Bellinger Signed-off-by: Greg Kroah-Hartman

iscsi-target: Always wait for kthread_should_stop() before kthread exit

2017-06-07T10:07:47Z

commit 5e0cf5e6c43b9e19fc0284f69e5cd2b4a47523b0 upstream. There are three timing problems in the kthread usages of iscsi_target_mod: - np_thread of struct iscsi_np - rx_thread and tx_thread of struct iscsi_conn In iscsit_close_connection(), it calls send_sig(SIGINT, conn->tx_thread, 1); kthread_stop(conn->tx_thread); In conn->tx_thread, which is iscsi_target_tx_thread(), when it receive SIGINT the kthread will exit without checking the return value of kthread_should_stop(). So if iscsi_target_tx_thread() exit right between send_sig(SIGINT...) and kthread_stop(...), the kthread_stop() will try to stop an already stopped kthread. This is invalid according to the documentation of kthread_stop(). (Fix -ECONNRESET logout handling in iscsi_target_tx_thread and early iscsi_target_rx_thread failure case - nab) Signed-off-by: Jiang Yi Signed-off-by: Nicholas Bellinger Signed-off-by: Greg Kroah-Hartman

iscsi-target: Set session_fall_back_to_erl0 when forcing reinstatement

2017-05-20T12:28:34Z

commit 197b806ae5db60c6f609d74da04ddb62ea5e1b00 upstream. While testing modification of per se_node_acl queue_depth forcing session reinstatement via lio_target_nacl_cmdsn_depth_store() -> core_tpg_set_initiator_node_queue_depth(), a hung task bug triggered when changing cmdsn_depth invoked session reinstatement while an iscsi login was already waiting for session reinstatement to complete. This can happen when an outstanding se_cmd descriptor is taking a long time to complete, and session reinstatement from iscsi login or cmdsn_depth change occurs concurrently. To address this bug, explicitly set session_fall_back_to_erl0 = 1 when forcing session reinstatement, so session reinstatement is not attempted if an active session is already being shutdown. This patch has been tested with two scenarios. The first when iscsi login is blocked waiting for iscsi session reinstatement to complete followed by queue_depth change via configfs, and second when queue_depth change via configfs us blocked followed by a iscsi login driven session reinstatement. Note this patch depends on commit d36ad77f702 to handle multiple sessions per se_node_acl when changing cmdsn_depth, and for pre v4.5 kernels will need to be included for stable as well. Reported-by: Gary Guo Tested-by: Gary Guo Cc: Gary Guo Signed-off-by: Nicholas Bellinger Signed-off-by: Greg Kroah-Hartman

target/fileio: Fix zero-length READ and WRITE handling

2017-05-20T12:28:34Z

commit 59ac9c078141b8fd0186c0b18660a1b2c24e724e upstream. This patch fixes zero-length READ and WRITE handling in target/FILEIO, which was broken a long time back by: Since: commit d81cb44726f050d7cf1be4afd9cb45d153b52066 Author: Paolo Bonzini Date: Mon Sep 17 16:36:11 2012 -0700 target: go through normal processing for all zero-length commands which moved zero-length READ and WRITE completion out of target-core, to doing submission into backend driver code. To address this, go ahead and invoke target_complete_cmd() for any non negative return value in fd_do_rw(). Signed-off-by: Bart Van Assche Reviewed-by: Hannes Reinecke Reviewed-by: Christoph Hellwig Cc: Andy Grover Cc: David Disseldorp Signed-off-by: Nicholas Bellinger Signed-off-by: Greg Kroah-Hartman

target: Fix compare_and_write_callback handling for non GOOD status

2017-05-20T12:28:34Z

commit a71a5dc7f833943998e97ca8fa6a4c708a0ed1a9 upstream. Following the bugfix for handling non SAM_STAT_GOOD COMPARE_AND_WRITE status during COMMIT phase in commit 9b2792c3da1, the same bug exists for the READ phase as well. This would manifest first as a lost SCSI response, and eventual hung task during fabric driver logout or re-login, as existing shutdown logic waited for the COMPARE_AND_WRITE se_cmd->cmd_kref to reach zero. To address this bug, compare_and_write_callback() has been changed to set post_ret = 1 and return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE as necessary to signal failure status. Reported-by: Bill Borsari Cc: Bill Borsari Tested-by: Gary Guo Cc: Gary Guo Signed-off-by: Nicholas Bellinger Signed-off-by: Greg Kroah-Hartman

target: Avoid mappedlun symlink creation during lun shutdown

2017-04-21T07:31:21Z

commit 49cb77e297dc611a1b795cfeb79452b3002bd331 upstream. 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 Signed-off-by: Nicholas Bellinger Signed-off-by: Greg Kroah-Hartman

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

2017-04-21T07:31:21Z

commit 1c99de981f30b3e7868b8d20ce5479fa1c0fea46 upstream. 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 Signed-off-by: Nicholas Bellinger Signed-off-by: Greg Kroah-Hartman

iscsi-target: Fix TMR reference leak during session shutdown

2017-04-21T07:31:20Z

commit efb2ea770bb3b0f40007530bc8b0c22f36e1c5eb upstream. 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 Signed-off-by: Nicholas Bellinger Signed-off-by: Greg Kroah-Hartman

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

2017-04-21T07:31:18Z

commit a5d68ba85801a78c892a0eb8efb711e293ed314b upstream. 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 Signed-off-by: Nicholas Bellinger Signed-off-by: Greg Kroah-Hartman

tcmu: Fix wrongly calculating of the base_command_size

2017-04-21T07:31:18Z

commit abe342a5b4b5aa579f6bf40ba73447c699e6b579 upstream. 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 Signed-off-by: Nicholas Bellinger Signed-off-by: Greg Kroah-Hartman