kernel/linux.git/drivers/target, branch v4.11.5

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

2017-06-14T13:07:44+00:00

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: Fix initial login PDU asynchronous socket close OOPs

2017-06-07T10:10:09+00:00

commit 25cdda95fda78d22d44157da15aa7ea34be3c804 upstream. 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 Signed-off-by: Nicholas Bellinger Signed-off-by: Greg Kroah-Hartman

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

2017-06-07T10:10:08+00:00

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

2017-05-20T12:49:40+00:00

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

2017-05-20T12:49:39+00:00

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

2017-05-20T12:49:39+00:00

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

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

2017-04-02T23:18:51+00:00

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

2017-04-02T21:10:16+00:00

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

2017-03-31T06:12:40+00:00

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

2017-03-31T03:34:58+00:00

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