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path: root/drivers/target/target_core_transport.c
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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>
2017-11-07target: Fix quiese during transport_write_pending_qf endless loopNicholas Bellinger
This patch fixes a potential end-less loop during QUEUE_FULL, where cmd->se_tfo->write_pending() callback fails repeatedly but __transport_wait_for_tasks() has already been invoked to quiese the outstanding se_cmd descriptor. To address this bug, this patch adds a CMD_T_STOP|CMD_T_ABORTED check within transport_write_pending_qf() and invokes the existing se_cmd->t_transport_stop_comp to signal quiese completion back to __transport_wait_for_tasks(). Cc: Mike Christie <mchristi@redhat.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Bryant G. Ly <bryantly@linux.vnet.ibm.com> Cc: Michael Cyr <mikecyr@linux.vnet.ibm.com> Cc: Potnuri Bharat Teja <bharat@chelsio.com> Cc: Sagi Grimberg <sagi@grimberg.me> Cc: stable@vger.kernel.org # 4.11+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-11-07target: Fix caw_sem leak in transport_generic_request_failureNicholas Bellinger
With the recent addition of transport_check_aborted_status() within transport_generic_request_failure() to avoid sending a SCSI status exception after CMD_T_ABORTED w/ TAS=1 has occured, it introduced a COMPARE_AND_WRITE early failure regression. Namely when COMPARE_AND_WRITE fails and se_device->caw_sem has been taken by sbc_compare_and_write(), if the new check for transport_check_aborted_status() returns true and exits, cmd->transport_complete_callback() -> compare_and_write_post() is skipped never releasing se_device->caw_sem. This regression was originally introduced by: commit e3b88ee95b4e4bf3e9729a4695d695b9c7c296c8 Author: Bart Van Assche <bart.vanassche@sandisk.com> Date: Tue Feb 14 16:25:45 2017 -0800 target: Fix handling of aborted failed commands To address this bug, move the transport_check_aborted_status() call after transport_complete_task_attr() and cmd->transport_complete_callback(). Cc: Mike Christie <mchristi@redhat.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Bart Van Assche <bart.vanassche@sandisk.com> Cc: stable@vger.kernel.org # 4.11+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-11-07target: Fix QUEUE_FULL + SCSI task attribute handlingNicholas Bellinger
This patch fixes a bug during QUEUE_FULL where transport_complete_qf() calls transport_complete_task_attr() after it's already been invoked by target_complete_ok_work() or transport_generic_request_failure() during initial completion, preceeding QUEUE_FULL. This will result in se_device->simple_cmds, se_device->dev_cur_ordered_id and/or se_device->dev_ordered_sync being updated multiple times for a single se_cmd. To address this bug, clear SCF_TASK_ATTR_SET after the first call to transport_complete_task_attr(), and avoid updating SCSI task attribute related counters for any subsequent calls. Also, when a se_cmd is deferred due to ordered tags and executed via target_restart_delayed_cmds(), set CMD_T_SENT before execution matching what target_execute_cmd() does. Cc: Michael Cyr <mikecyr@linux.vnet.ibm.com> Cc: Bryant G. Ly <bryantly@linux.vnet.ibm.com> Cc: Mike Christie <mchristi@redhat.com> Cc: Hannes Reinecke <hare@suse.com> Cc: stable@vger.kernel.org # 4.1+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-11-04target: Inline transport_put_cmd()Bart Van Assche
Since all transput_put_cmd() does is to call target_put_sess_cmd(), inline transport_put_cmd() into its callers. Leave out the BUG_ON() statement because if cmd->se_tfo == NULL then cmd->cmd_kref is 0 and kref_put() will complain anyway. Notes: - transport_init_se_cmd() initializes both .se_tfo and .cmd_kref. - The only target driver that does not call transport_init_se_cmd() for all commands is the iSCSI target driver. See also iscsi_target_rx_opcode(). Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Mike Christie <mchristi@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-11-04target: Suppress gcc 7 fallthrough warningsBart Van Assche
Avoid that gcc 7 reports the following warning when building with W=1: warning: this statement may fall through [-Wimplicit-fallthrough=] Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Mike Christie <mchristi@redhat.com> Cc: Varun Prakash <varun@chelsio.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-11-04target: return SAM_STAT_TASK_SET_FULL for TCM_OUT_OF_RESOURCESMike Christie
TCM_OUT_OF_RESOURCES is getting translated to TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE which seems like a heavy error when we just cannot allocate a resource that may be allocatable later. This has us translate TCM_OUT_OF_RESOURCES to SAM_STAT_TASK_SET_FULL instead. Signed-off-by: Mike Christie <mchristi@redhat.com> 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>
2017-08-09target: Fix node_acl demo-mode + uncached dynamic shutdown regressionNicholas Bellinger
This patch fixes a generate_node_acls = 1 + cache_dynamic_acls = 0 regression, that was introduced by commit 01d4d673558985d9a118e1e05026633c3e2ade9b Author: Nicholas Bellinger <nab@linux-iscsi.org> Date: Wed Dec 7 12:55:54 2016 -0800 which originally had the proper list_del_init() usage, but was dropped during list review as it was thought unnecessary by HCH. However, list_del_init() usage is required during the special generate_node_acls = 1 + cache_dynamic_acls = 0 case when transport_free_session() does a list_del(&se_nacl->acl_list), followed by target_complete_nacl() doing the same thing. This was manifesting as a general protection fault as reported by Justin: kernel: general protection fault: 0000 [#1] SMP kernel: Modules linked in: kernel: CPU: 0 PID: 11047 Comm: iscsi_ttx Not tainted 4.13.0-rc2.x86_64.1+ #20 kernel: Hardware name: Intel Corporation S5500BC/S5500BC, BIOS S5500.86B.01.00.0064.050520141428 05/05/2014 kernel: task: ffff88026939e800 task.stack: ffffc90007884000 kernel: RIP: 0010:target_put_nacl+0x49/0xb0 kernel: RSP: 0018:ffffc90007887d70 EFLAGS: 00010246 kernel: RAX: dead000000000200 RBX: ffff8802556ca000 RCX: 0000000000000000 kernel: RDX: dead000000000100 RSI: 0000000000000246 RDI: ffff8802556ce028 kernel: RBP: ffffc90007887d88 R08: 0000000000000001 R09: 0000000000000000 kernel: R10: ffffc90007887df8 R11: ffffea0009986900 R12: ffff8802556ce020 kernel: R13: ffff8802556ce028 R14: ffff8802556ce028 R15: ffffffff88d85540 kernel: FS: 0000000000000000(0000) GS:ffff88027fc00000(0000) knlGS:0000000000000000 kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 kernel: CR2: 00007fffe36f5f94 CR3: 0000000009209000 CR4: 00000000003406f0 kernel: DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 kernel: DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 kernel: Call Trace: kernel: transport_free_session+0x67/0x140 kernel: transport_deregister_session+0x7a/0xc0 kernel: iscsit_close_session+0x92/0x210 kernel: iscsit_close_connection+0x5f9/0x840 kernel: iscsit_take_action_for_connection_exit+0xfe/0x110 kernel: iscsi_target_tx_thread+0x140/0x1e0 kernel: ? wait_woken+0x90/0x90 kernel: kthread+0x124/0x160 kernel: ? iscsit_thread_get_cpumask+0x90/0x90 kernel: ? kthread_create_on_node+0x40/0x40 kernel: ret_from_fork+0x22/0x30 kernel: Code: 00 48 89 fb 4c 8b a7 48 01 00 00 74 68 4d 8d 6c 24 08 4c 89 ef e8 e8 28 43 00 48 8b 93 20 04 00 00 48 8b 83 28 04 00 00 4c 89 ef <48> 89 42 08 48 89 10 48 b8 00 01 00 00 00 00 ad de 48 89 83 20 kernel: RIP: target_put_nacl+0x49/0xb0 RSP: ffffc90007887d70 kernel: ---[ end trace f12821adbfd46fed ]--- To address this, go ahead and use proper list_del_list() for all cases of se_nacl->acl_list deletion. Reported-by: Justin Maggard <jmaggard01@gmail.com> Tested-by: Justin Maggard <jmaggard01@gmail.com> Cc: Justin Maggard <jmaggard01@gmail.com> Cc: stable@vger.kernel.org # 4.1+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-07-13Merge 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: "It's been usually busy for summer, with most of the efforts centered around TCMU developments and various target-core + fabric driver bug fixing activities. Not particularly large in terms of LoC, but lots of smaller patches from many different folks. The highlights include: - ibmvscsis logical partition manager support (Michael Cyr + Bryant Ly) - Convert target/iblock WRITE_SAME to blkdev_issue_zeroout (hch + nab) - Add support for TMR percpu LUN reference counting (nab) - Fix a potential deadlock between EXTENDED_COPY and iscsi shutdown (Bart) - Fix COMPARE_AND_WRITE caw_sem leak during se_cmd quiesce (Jiang Yi) - Fix TMCU module removal (Xiubo Li) - Fix iser-target OOPs during login failure (Andrea Righi + Sagi) - Breakup target-core free_device backend driver callback (mnc) - Perform TCMU add/delete/reconfig synchronously (mnc) - Fix TCMU multiple UIO open/close sequences (mnc) - Fix TCMU CHECK_CONDITION sense handling (mnc) - Fix target-core SAM_STAT_BUSY + TASK_SET_FULL handling (mnc + nab) - Introduce TYPE_ZBC support in PSCSI (Damien Le Moal) - Fix possible TCMU memory leak + OOPs when recalculating cmd base size (Xiubo Li + Bryant Ly + Damien Le Moal + mnc) - Add login_keys_workaround attribute for non RFC initiators (Robert LeBlanc + Arun Easi + nab)" * 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (68 commits) iscsi-target: Add login_keys_workaround attribute for non RFC initiators Revert "qla2xxx: Fix incorrect tcm_qla2xxx_free_cmd use during TMR ABORT" tcmu: clean up the code and with one small fix tcmu: Fix possbile memory leak / OOPs when recalculating cmd base size target: export lio pgr/alua support as device attr target: Fix return sense reason in target_scsi3_emulate_pr_out target: Fix cmd size for PR-OUT in passthrough_parse_cdb tcmu: Fix dev_config_store target: pscsi: Introduce TYPE_ZBC support target: Use macro for WRITE_VERIFY_32 operation codes target: fix SAM_STAT_BUSY/TASK_SET_FULL handling target: remove transport_complete pscsi: finish cmd processing from pscsi_req_done tcmu: fix sense handling during completion target: add helper to copy sense to se_cmd buffer target: do not require a transport_complete for SCF_TRANSPORT_TASK_SENSE target: make device_mutex and device_list static tcmu: Fix flushing cmd entry dcache page tcmu: fix multiple uio open/close sequences tcmu: drop configured check in destroy ...
2017-07-12mm, tree wide: replace __GFP_REPEAT by __GFP_RETRY_MAYFAIL with more useful ↵Michal Hocko
semantic __GFP_REPEAT was designed to allow retry-but-eventually-fail semantic to the page allocator. This has been true but only for allocations requests larger than PAGE_ALLOC_COSTLY_ORDER. It has been always ignored for smaller sizes. This is a bit unfortunate because there is no way to express the same semantic for those requests and they are considered too important to fail so they might end up looping in the page allocator for ever, similarly to GFP_NOFAIL requests. Now that the whole tree has been cleaned up and accidental or misled usage of __GFP_REPEAT flag has been removed for !costly requests we can give the original flag a better name and more importantly a more useful semantic. Let's rename it to __GFP_RETRY_MAYFAIL which tells the user that the allocator would try really hard but there is no promise of a success. This will work independent of the order and overrides the default allocator behavior. Page allocator users have several levels of guarantee vs. cost options (take GFP_KERNEL as an example) - GFP_KERNEL & ~__GFP_RECLAIM - optimistic allocation without _any_ attempt to free memory at all. The most light weight mode which even doesn't kick the background reclaim. Should be used carefully because it might deplete the memory and the next user might hit the more aggressive reclaim - GFP_KERNEL & ~__GFP_DIRECT_RECLAIM (or GFP_NOWAIT)- optimistic allocation without any attempt to free memory from the current context but can wake kswapd to reclaim memory if the zone is below the low watermark. Can be used from either atomic contexts or when the request is a performance optimization and there is another fallback for a slow path. - (GFP_KERNEL|__GFP_HIGH) & ~__GFP_DIRECT_RECLAIM (aka GFP_ATOMIC) - non sleeping allocation with an expensive fallback so it can access some portion of memory reserves. Usually used from interrupt/bh context with an expensive slow path fallback. - GFP_KERNEL - both background and direct reclaim are allowed and the _default_ page allocator behavior is used. That means that !costly allocation requests are basically nofail but there is no guarantee of that behavior so failures have to be checked properly by callers (e.g. OOM killer victim is allowed to fail currently). - GFP_KERNEL | __GFP_NORETRY - overrides the default allocator behavior and all allocation requests fail early rather than cause disruptive reclaim (one round of reclaim in this implementation). The OOM killer is not invoked. - GFP_KERNEL | __GFP_RETRY_MAYFAIL - overrides the default allocator behavior and all allocation requests try really hard. The request will fail if the reclaim cannot make any progress. The OOM killer won't be triggered. - GFP_KERNEL | __GFP_NOFAIL - overrides the default allocator behavior and all allocation requests will loop endlessly until they succeed. This might be really dangerous especially for larger orders. Existing users of __GFP_REPEAT are changed to __GFP_RETRY_MAYFAIL because they already had their semantic. No new users are added. __alloc_pages_slowpath is changed to bail out for __GFP_RETRY_MAYFAIL if there is no progress and we have already passed the OOM point. This means that all the reclaim opportunities have been exhausted except the most disruptive one (the OOM killer) and a user defined fallback behavior is more sensible than keep retrying in the page allocator. [akpm@linux-foundation.org: fix arch/sparc/kernel/mdesc.c] [mhocko@suse.com: semantic fix] Link: http://lkml.kernel.org/r/20170626123847.GM11534@dhcp22.suse.cz [mhocko@kernel.org: address other thing spotted by Vlastimil] Link: http://lkml.kernel.org/r/20170626124233.GN11534@dhcp22.suse.cz Link: http://lkml.kernel.org/r/20170623085345.11304-3-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Alex Belits <alex.belits@cavium.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Christoph Hellwig <hch@infradead.org> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: David Daney <david.daney@cavium.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@suse.de> Cc: NeilBrown <neilb@suse.com> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-06target: fix SAM_STAT_BUSY/TASK_SET_FULL handlingMike Christie
If the scsi status was not SAM_STAT_GOOD or there was no transport sense, we would ignore the scsi status and do a generic not ready LUN communication failure check condition failure. The problem is that LUN COMM failure is treated as a hard error sometimes and will cause apps to get IO errors instead of the OS's SCSI layer retrying. For example, the tcmu daemon will return SAM_STAT_QUEUE_FULL when memory runs low and can still make progress but wants the initiator to reduce the work load. Windows will fail this error directly the app instead of retrying. This patch is based on Nick's "target/iblock: Use -EAGAIN/-ENOMEM to propigate SAM BUSY/TASK_SET_FULL" patch here: http://comments.gmane.org/gmane.linux.scsi.target.devel/11301 but instead of only setting SAM_STAT_GOOD, SAM_STAT_TASK_SET_FULL and SAM_STAT_BUSY as success, it sets all non check condition status as success so they are passed back to the initiator, so passthrough type backends can return all SCSI status codes. Since only passthrough uses this, I was not sure if we wanted to add checks for non-passthrough and specific codes. Signed-off-by: Mike Christie <mchristi@redhat.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-07-06target: remove transport_completeMike Christie
transport_complete is no longer used, so drop the code. Signed-off-by: Mike Christie <mchristi@redhat.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-07-06target: add helper to copy sense to se_cmd bufferMike Christie
This adds a helper to copy sense from backend module buffer to the se_cmd's sense buffer. Signed-off-by: Mike Christie <mchristi@redhat.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-07-06target: do not require a transport_complete for SCF_TRANSPORT_TASK_SENSEMike Christie
tcmu needs to pass raw sense to target_complete_cmd, but a a transport_complete callout is akward to implement for it. This moves the check for SCF_TRANSPORT_TASK_SENSE so any backend can pass sense. Signed-off-by: Mike Christie <mchristi@redhat.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-07-06target: Fix COMPARE_AND_WRITE caw_sem leak during se_cmd quiesceJiang Yi
This patch addresses a COMPARE_AND_WRITE se_device->caw_sem leak, that would be triggered during normal se_cmd shutdown or abort via __transport_wait_for_tasks(). This would occur because target_complete_cmd() would catch this early and do complete_all(&cmd->t_transport_stop_comp), but since target_complete_ok_work() or target_complete_failure_work() are never called to invoke se_cmd->transport_complete_callback(), the COMPARE_AND_WRITE specific callbacks never release caw_sem. To address this special case, go ahead and release caw_sem directly from target_complete_cmd(). (Remove '&& success' from check, to release caw_sem regardless of scsi_status - nab) Signed-off-by: Jiang Yi <jiangyilism@gmail.com> Cc: <stable@vger.kernel.org> # 3.14+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-07-06target: Introduce a function that shows the command stateBart Van Assche
Introduce target_show_cmd() and use it where appropriate. If transport_wait_for_tasks() takes too long, make it show the state of the command it is waiting for. (Add missing brackets around multi-line conditions - nab) Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Andy Grover <agrover@redhat.com> Cc: David Disseldorp <ddiss@suse.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-07-06target: Fix transport_init_se_cmd()Bart Van Assche
Avoid that aborting a command before it has been submitted onto a workqueue triggers the following warning: INFO: trying to register non-static key. the code is fine but needs lockdep annotation. turning off the locking correctness validator. CPU: 3 PID: 46 Comm: kworker/u8:1 Not tainted 4.12.0-rc2-dbg+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org 04/01/2014 Workqueue: tmr-iblock target_tmr_work [target_core_mod] Call Trace: dump_stack+0x86/0xcf register_lock_class+0xe8/0x570 __lock_acquire+0xa1/0x11d0 lock_acquire+0x59/0x80 flush_work+0x42/0x2b0 __cancel_work_timer+0x10c/0x180 cancel_work_sync+0xb/0x10 core_tmr_lun_reset+0x352/0x740 [target_core_mod] target_tmr_work+0xd6/0x130 [target_core_mod] process_one_work+0x1ca/0x3f0 worker_thread+0x49/0x3b0 kthread+0x109/0x140 ret_from_fork+0x31/0x40 Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.com> Cc: David Disseldorp <ddiss@suse.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-07-06target: Add TARGET_SCF_LOOKUP_LUN_FROM_TAG support for ABORT_TASKNicholas Bellinger
This patch introduces support in target_submit_tmr() for locating a unpacked_lun from an existing se_cmd->tag during ABORT_TASK. When TARGET_SCF_LOOKUP_LUN_FROM_TAG is set, target_submit_tmr() will do the extra lookup via target_lookup_lun_from_tag() and subsequently invoke transport_lookup_tmr_lun() so a proper percpu se_lun->lun_ref is taken before workqueue dispatch into se_device->tmr_wq happens. Aside from the extra target_lookup_lun_from_tag(), the existing code-path remains unchanged. Reviewed-by: Himanshu Madhani <himanshu.madhani@cavium.com> Reviewed-by: Quinn Tran <quinn.tran@cavium.com> Cc: Mike Christie <mchristi@redhat.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-07-06target: Add support for TMR percpu reference countingNicholas Bellinger
This patch introduces TMR percpu reference counting using se_lun->lun_ref in transport_lookup_tmr_lun(), following how existing non TMR per se_lun reference counting works within transport_lookup_cmd_lun(). It also adds explicit transport_lun_remove_cmd() calls to drop the reference in the three tmr related locations that invoke transport_cmd_check_stop_to_fabric(); - target_tmr_work() during normal ->queue_tm_rsp() - target_complete_tmr_failure() during error ->queue_tm_rsp() - transport_generic_handle_tmr() during early failure Also, note the exception paths in transport_generic_free_cmd() and transport_cmd_finish_abort() already check SCF_SE_LUN_CMD, and will invoke transport_lun_remove_cmd() when necessary. Reviewed-by: Himanshu Madhani <himanshu.madhani@cavium.com> Reviewed-by: Quinn Tran <quinn.tran@cavium.com> Cc: Mike Christie <mchristi@redhat.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-06-08target: Fix kref->refcount underflow in transport_cmd_finish_abortNicholas Bellinger
This patch fixes a se_cmd->cmd_kref underflow during CMD_T_ABORTED when a fabric driver drops it's second reference from below the target_core_tmr.c based callers of transport_cmd_finish_abort(). Recently with the conversion of kref to refcount_t, this bug was manifesting itself as: [705519.601034] refcount_t: underflow; use-after-free. [705519.604034] INFO: NMI handler (kgdb_nmi_handler) took too long to run: 20116.512 msecs [705539.719111] ------------[ cut here ]------------ [705539.719117] WARNING: CPU: 3 PID: 26510 at lib/refcount.c:184 refcount_sub_and_test+0x33/0x51 Since the original kref atomic_t based kref_put() didn't check for underflow and only invoked the final callback when zero was reached, this bug did not manifest in practice since all se_cmd memory is using preallocated tags. To address this, go ahead and propigate the existing return from transport_put_cmd() up via transport_cmd_finish_abort(), and change transport_cmd_finish_abort() + core_tmr_handle_tas_abort() callers to only do their local target_put_sess_cmd() if necessary. Reported-by: Bart Van Assche <bart.vanassche@sandisk.com> Tested-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Mike Christie <mchristi@redhat.com> Cc: Hannes Reinecke <hare@suse.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Himanshu Madhani <himanshu.madhani@qlogic.com> Cc: Sagi Grimberg <sagig@mellanox.com> Cc: stable@vger.kernel.org # 3.14+ Tested-by: Gary Guo <ghg@datera.io> Tested-by: Chu Yuan Lin <cyl@datera.io> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-05-15target: Re-add check to reject control WRITEs with overflow dataNicholas Bellinger
During v4.3 when the overflow/underflow check was relaxed by commit c72c525022: commit c72c5250224d475614a00c1d7e54a67f77cd3410 Author: Roland Dreier <roland@purestorage.com> 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 <bart.vanassche@sandisk.com> Cc: Roland Dreier <roland@purestorage.com> Cc: <stable@vger.kernel.org> # v4.3+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-05-01target: Use kmalloc_array() in transport_kmap_data_sg()Markus Elfring
A multiplication for the size determination of a memory allocation indicated that an array data structure should be processed. Thus use the corresponding function "kmalloc_array". This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-03-30target: Fix unknown fabric callback queue-full errorsNicholas Bellinger
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 <bharat@chelsio.com> Reviewed-by: Potnuri Bharat Teja <bharat@chelsio.com> Tested-by: Potnuri Bharat Teja <bharat@chelsio.com> Cc: Potnuri Bharat Teja <bharat@chelsio.com> Reported-by: Steve Wise <swise@opengridcomputing.com> Cc: Steve Wise <swise@opengridcomputing.com> Cc: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-03-18target: Drop pointless tfo->check_stop_free checkNicholas Bellinger
All in-tree fabric drivers provide a tfo->check_stop_free(), so there is no need to do the extra check within existing transport_cmd_check_stop_to_fabric() code. Just to be sure, add a check in target_fabric_tf_ops_check() to notify any out-of-tree drivers that might be missing it. Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-02-26target: Fix NULL dereference during LUN lookup + active I/O shutdownNicholas Bellinger
When transport_clear_lun_ref() is shutting down a se_lun via configfs with new I/O in-flight, it's possible to trigger a NULL pointer dereference in transport_lookup_cmd_lun() due to the fact percpu_ref_get() doesn't do any __PERCPU_REF_DEAD checking before incrementing lun->lun_ref.count after lun->lun_ref has switched to atomic_t mode. This results in a NULL pointer dereference as LUN shutdown code in core_tpg_remove_lun() continues running after the existing ->release() -> core_tpg_lun_ref_release() callback completes, and clears the RCU protected se_lun->lun_se_dev pointer. During the OOPs, the state of lun->lun_ref in the process which triggered the NULL pointer dereference looks like the following on v4.1.y stable code: struct se_lun { lun_link_magic = 4294932337, lun_status = TRANSPORT_LUN_STATUS_FREE, ..... lun_se_dev = 0x0, lun_sep = 0x0, ..... lun_ref = { count = { counter = 1 }, percpu_count_ptr = 3, release = 0xffffffffa02fa1e0 <core_tpg_lun_ref_release>, confirm_switch = 0x0, force_atomic = false, rcu = { next = 0xffff88154fa1a5d0, func = 0xffffffff8137c4c0 <percpu_ref_switch_to_atomic_rcu> } } } To address this bug, use percpu_ref_tryget_live() to ensure once __PERCPU_REF_DEAD is visable on all CPUs and ->lun_ref has switched to atomic_t, all new I/Os will fail to obtain a new lun->lun_ref reference. Also use an explicit percpu_ref_kill_and_confirm() callback to block on ->lun_ref_comp to allow the first stage and associated RCU grace period to complete, and then block on ->lun_ref_shutdown waiting for the final percpu_ref_put() to drop the last reference via transport_lun_remove_cmd() before continuing with core_tpg_remove_lun() shutdown. Reported-by: Rob Millner <rlm@daterainc.com> Tested-by: Rob Millner <rlm@daterainc.com> Cc: Rob Millner <rlm@daterainc.com> Tested-by: Vaibhav Tandon <vst@datera.io> Cc: Vaibhav Tandon <vst@datera.io> Tested-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com> Cc: <stable@vger.kernel.org> # v3.14+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-02-20target: Fix handling of aborted failed commandsBart Van Assche
If a target driver (e.g. tcm_qla2xxx) calls transport_generic_request_failure() to report that receiving data has failed and that SCSI command has already been aborted by the initiator, ensure that the SCSI status ABORTED is sent back to the initiator instead of the sense code provided by the target driver. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Christoph Hellwig <hch@lst.de> Cc: David Disseldorp <ddiss@suse.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-02-09target: Remove command flag CMD_T_DEV_ACTIVEBart Van Assche
The code that tests the CMD_T_DEV_ACTIVE flag has been removed. Hence also remove the flag itself. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Andy Grover <agrover@redhat.com> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-02-09target: Remove command flag CMD_T_BUSYBart Van Assche
The patch that reworks task management function handling guarantees that target_remove_from_state_list() is always called with CMD_T_BUSY cleared. Since that function is the only function that tests that flag this means that that flag is now superfluous. Hence remove that flag. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Andy Grover <agrover@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-02-09target: Move session check from target_put_sess_cmd() into ↵Bart Van Assche
target_release_cmd_kref() This patch does not change any functionality. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Christoph Hellwig <hch@lst.de> Cc: David Disseldorp <ddiss@suse.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-02-09target: Inline transport_cmd_check_stop()Bart Van Assche
The function transport_cmd_check_stop() has two callers. These callers invoke this function as follows: * transport_cmd_check_stop(cmd, true, false) * transport_cmd_check_stop(cmd, false, true) Hence inline this function into its callers. This patch does not change any functionality but improves source code readability. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Andy Grover <agrover@redhat.com> Cc: David Disseldorp <ddiss@suse.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-02-09target: Remove an overly chatty debug messageBart Van Assche
Enabling dynamic debug for the target_core_mod kernel module causes the system log to be spammed with the "Incremented ..." message. Hence remove it. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Andy Grover <agrover@redhat.com> Cc: David Disseldorp <ddiss@suse.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-02-09target: Stop execution if CMD_T_STOP has been setBart Van Assche
Stop execution if CMD_T_STOP has been set for a command just after the command has been added to the device command list and before .write_pending() is called. The following sequence can trigger this: - transport_handle_cdb_direct() gets called. This function namely sets CMD_T_ACTIVE before it calls transport_generic_new_cmd(). - __transport_wait_for_tasks() is called concurrently. This function sets CMD_T_STOP for all active commands that have not been aborted. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Andy Grover <agrover@redhat.com> Cc: David Disseldorp <ddiss@suse.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-02-09target: Correct transport_wait_for_tasks() documentationBart Van Assche
transport_wait_for_tasks() not only waits for command completion but also sets CMD_T_STOP. Additionally, this function is not only called by frontend drivers but also by the target core. Update the transport_wait_for_tasks() documentation to reflect this. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Andy Grover <agrover@redhat.com> Cc: David Disseldorp <ddiss@suse.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-02-08target: Fix multi-session dynamic se_node_acl double free OOPsNicholas Bellinger
This patch addresses a long-standing bug with multi-session (eg: iscsi-target + iser-target) se_node_acl dynamic free withini transport_deregister_session(). This bug is caused when a storage endpoint is configured with demo-mode (generate_node_acls = 1 + cache_dynamic_acls = 1) initiators, and initiator login creates a new dynamic node acl and attaches two sessions to it. After that, demo-mode for the storage instance is disabled via configfs (generate_node_acls = 0 + cache_dynamic_acls = 0) and the existing dynamic acl is never converted to an explicit ACL. The end result is dynamic acl resources are released twice when the sessions are shutdown in transport_deregister_session(). If the storage instance is not changed to disable demo-mode, or the dynamic acl is converted to an explict ACL, or there is only a single session associated with the dynamic ACL, the bug is not triggered. To address this big, move the release of dynamic se_node_acl memory into target_complete_nacl() so it's only freed once when se_node_acl->acl_kref reaches zero. (Drop unnecessary list_del_init usage - HCH) Reported-by: Rob Millner <rlm@daterainc.com> Tested-by: Rob Millner <rlm@daterainc.com> Cc: Rob Millner <rlm@daterainc.com> Cc: stable@vger.kernel.org # 4.1+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-02-08target: Fix early transport_generic_handle_tmr abort scenarioNicholas Bellinger
This patch fixes a bug where incoming task management requests can be explicitly aborted during an active LUN_RESET, but who's struct work_struct are canceled in-flight before execution. This occurs when core_tmr_drain_tmr_list() invokes cancel_work_sync() for the incoming se_tmr_req->task_cmd->work, resulting in cmd->work for target_tmr_work() never getting invoked and the aborted TMR waiting indefinately within transport_wait_for_tasks(). To address this case, perform a CMD_T_ABORTED check early in transport_generic_handle_tmr(), and invoke the normal path via transport_cmd_check_stop_to_fabric() to complete any TMR kthreads blocked waiting for CMD_T_STOP in transport_wait_for_tasks(). Also, move the TRANSPORT_ISTATE_PROCESSING assignment earlier into transport_generic_handle_tmr() so the existing check in core_tmr_drain_tmr_list() avoids attempting abort the incoming se_tmr_req->task_cmd->work if it has already been queued into se_device->tmr_wq. Reported-by: Rob Millner <rlm@daterainc.com> Tested-by: Rob Millner <rlm@daterainc.com> Cc: Rob Millner <rlm@daterainc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: stable@vger.kernel.org # 3.14+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-01-10target: add XCOPY target/segment desc sense codesDavid Disseldorp
As defined in http://www.t10.org/lists/asc-num.htm. To be used during validation of XCOPY target and segment descriptor lists. Signed-off-by: David Disseldorp <ddiss@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
2016-10-21target: fix potential race window in target_sess_cmd_list_waiting()Hannes Reinecke
target_sess_cmd_list_waiting() might hit on a condition where the kref for the command is already 0, but the destructor has not been called yet (or is stuck in waiting for a spin lock). Rather than leaving the command on the list we should explicitly remove it to avoid race issues later on. Signed-off-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-10-19Revert "target: Fix residual overflow handling in ↵Nicholas Bellinger
target_complete_cmd_with_length" This reverts commit c1ccbfe0311e2380a6d2dcb0714b36904f5d586f. Reverting this patch, as it incorrectly assumes the additional length for INQUIRY in target_complete_cmd_with_length() is SCSI allocation length, which breaks existing user-space code when SCSI allocation length is smaller than additional length. root@scsi-mq:~# sg_inq --len=4 -vvvv /dev/sdb found bsg_major=253 open /dev/sdb with flags=0x800 inquiry cdb: 12 00 00 00 04 00 duration=0 ms inquiry: pass-through requested 4 bytes (data-in) but got -28 bytes inquiry: pass-through can't get negative bytes, say it got none inquiry: got too few bytes (0) INQUIRY resid (32) should never exceed requested len=4 inquiry: failed requesting 4 byte response: Malformed response to SCSI command [resid=32] AFAICT the original change was not to address a specific host issue, so go ahead and revert to original logic for now. Cc: Douglas Gilbert <dgilbert@interlog.com> Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: Sumit Rai <sumitrai96@gmail.com> Cc: stable@vger.kernel.org # 4.8+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-10-19target: Make EXTENDED_COPY 0xe4 failure return COPY TARGET DEVICE NOT REACHABLENicholas Bellinger
This patch addresses a bug where EXTENDED_COPY across multiple LUNs results in a CHECK_CONDITION when the source + destination are not located on the same physical node. ESX Host environments expect sense COPY_ABORTED w/ COPY TARGET DEVICE NOT REACHABLE to be returned when this occurs, in order to signal fallback to local copy method. As described in section 6.3.3 of spc4r22: "If it is not possible to complete processing of a segment because the copy manager is unable to establish communications with a copy target device, because the copy target device does not respond to INQUIRY, or because the data returned in response to INQUIRY indicates an unsupported logical unit, then the EXTENDED COPY command shall be terminated with CHECK CONDITION status, with the sense key set to COPY ABORTED, and the additional sense code set to COPY TARGET DEVICE NOT REACHABLE." Tested on v4.1.y with ESX v5.5u2+ with BlockCopy across multiple nodes. Reported-by: Nixon Vincent <nixon.vincent@calsoftinc.com> Tested-by: Nixon Vincent <nixon.vincent@calsoftinc.com> Cc: Nixon Vincent <nixon.vincent@calsoftinc.com> Tested-by: Dinesh Israni <ddi@datera.io> Signed-off-by: Dinesh Israni <ddi@datera.io> Cc: Dinesh Israni <ddi@datera.io> Cc: stable@vger.kernel.org # 3.14+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-10-19target: Re-add missing SCF_ACK_KREF assignment in v4.1.yNicholas Bellinger
This patch fixes a regression in >= v4.1.y code where the original SCF_ACK_KREF assignment in target_get_sess_cmd() was dropped upstream in commit 054922bb, but the series for addressing TMR ABORT_TASK + LUN_RESET with fabric session reinstatement in commit febe562c20 still depends on this code in transport_cmd_finish_abort(). The regression manifests itself as a se_cmd->cmd_kref +1 leak, where ABORT_TASK + LUN_RESET can hang indefinately for a specific I_T session for drivers using SCF_ACK_KREF, resulting in hung kthreads. This patch has been verified with v4.1.y code. Reported-by: Vaibhav Tandon <vst@datera.io> Tested-by: Vaibhav Tandon <vst@datera.io> Cc: Vaibhav Tandon <vst@datera.io> Cc: stable@vger.kernel.org # 4.1+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-07-23target: Fix residual overflow handling in target_complete_cmd_with_lengthSumit Rai
This patch fixes residual overflow handling to correctly set the residual_count using SPDTL, instead of SCSI Allocation Length. Allocation Length is the maximum value of the SPDTL and not substitute for it, hence it shouldn’t be used to calculate ResidualCount except for cases where SPDTL > Allocation Length and Data is truncated (in that case both Alloc Len and SPDTL are same). (SPC 5r01 Section 4.2.5.6). Thanks to Ajay Nair in assisting with this patch. Signed-off-by: Sumit Rai <sumitrai96@gmail.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-07-20target: Fix ordered task CHECK_CONDITION early exception handlingNicholas Bellinger
If a Simple command is sent with a failure, target_setup_cmd_from_cdb returns with TCM_UNSUPPORTED_SCSI_OPCODE or TCM_INVALID_CDB_FIELD. So in the cases where target_setup_cmd_from_cdb returns an error, we never get far enough to call target_execute_cmd to increment simple_cmds. Since simple_cmds isn't incremented, the result of the failure from target_setup_cmd_from_cdb causes transport_generic_request_failure to decrement simple_cmds, due to call to transport_complete_task_attr. With this dev->simple_cmds or dev->dev_ordered_sync is now -1, not 0. So when a subsequent command with an Ordered Task is sent, it causes a hang, since dev->simple_cmds is at -1. Tested-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com> Signed-off-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com> Tested-by: Michael Cyr <mikecyr@linux.vnet.ibm.com> Signed-off-by: Michael Cyr <mikecyr@linux.vnet.ibm.com> Cc: stable@vger.kernel.org # 4.4+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-07-20target: Fix ordered task target_setup_cmd_from_cdb exception hangNicholas Bellinger
If a command with a Simple task attribute is failed due to a Unit Attention, then a subsequent command with an Ordered task attribute will hang forever. The reason for this is that the Unit Attention status is checked for in target_setup_cmd_from_cdb, before the call to target_execute_cmd, which calls target_handle_task_attr, which in turn increments dev->simple_cmds. However, transport_generic_request_failure still calls transport_complete_task_attr, which will decrement dev->simple_cmds. In this case, simple_cmds is now -1. So when a command with the Ordered task attribute is sent, target_handle_task_attr sees that dev->simple_cmds is not 0, so it decides it can't execute the command until all the (nonexistent) Simple commands have completed. Reported-by: Michael Cyr <mikecyr@linux.vnet.ibm.com> Tested-by: Michael Cyr <mikecyr@linux.vnet.ibm.com> Reported-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com> Tested-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com> Cc: stable@vger.kernel.org # 4.4+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-07-20target: Fix race between iscsi-target connection shutdown + ABORT_TASKNicholas Bellinger
This patch fixes a race in iscsit_release_commands_from_conn() -> iscsit_free_cmd() -> transport_generic_free_cmd() + wait_for_tasks=1, where CMD_T_FABRIC_STOP could end up being set after the final kref_put() is called from core_tmr_abort_task() context. This results in transport_generic_free_cmd() blocking indefinately on se_cmd->cmd_wait_comp, because the target_release_cmd_kref() check for CMD_T_FABRIC_STOP returns false. To address this bug, make iscsit_release_commands_from_conn() do list_splice and set CMD_T_FABRIC_STOP early while holding iscsi_conn->cmd_lock. Also make iscsit_aborted_task() only remove iscsi_cmd_t if CMD_T_FABRIC_STOP has not already been set. Finally in target_release_cmd_kref(), only honor fabric_stop if CMD_T_ABORTED has been set. Cc: Mike Christie <mchristi@redhat.com> Cc: Quinn Tran <quinn.tran@qlogic.com> Cc: Himanshu Madhani <himanshu.madhani@qlogic.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.de> Cc: stable@vger.kernel.org # 3.14+ Tested-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-07-20target: Fix missing complete during ABORT_TASK + CMD_T_FABRIC_STOPNicholas Bellinger
During transport_generic_free_cmd() with a concurrent TMR ABORT_TASK and shutdown CMD_T_FABRIC_STOP bit set, the caller will be blocked on se_cmd->cmd_wait_stop completion until the final kref_put() -> target_release_cmd_kref() has been invoked to call complete(). However, when ABORT_TASK is completed with FUNCTION_COMPLETE in core_tmr_abort_task(), the aborted se_cmd will have already been removed from se_sess->sess_cmd_list via list_del_init(). This results in target_release_cmd_kref() hitting the legacy list_empty() == true check, invoking ->release_cmd() but skipping complete() to wakeup se_cmd->cmd_wait_stop blocked earlier in transport_generic_free_cmd() code. To address this bug, it's safe to go ahead and drop the original list_empty() check so that fabric_stop invokes the complete() as expected, since list_del_init() can safely be used on a empty list. Cc: Mike Christie <mchristi@redhat.com> Cc: Quinn Tran <quinn.tran@qlogic.com> Cc: Himanshu Madhani <himanshu.madhani@qlogic.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.de> Cc: stable@vger.kernel.org # 3.14+ Tested-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-05-28Merge 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: "Here are the outstanding target pending updates for v4.7-rc1. The highlights this round include: - Allow external PR/ALUA metadata path be defined at runtime via top level configfs attribute (Lee) - Fix target session shutdown bug for ib_srpt multi-channel (hch) - Make TFO close_session() and shutdown_session() optional (hch) - Drop se_sess->sess_kref + convert tcm_qla2xxx to internal kref (hch) - Add tcm_qla2xxx endpoint attribute for basic FC jammer (Laurence) - Refactor iscsi-target RX/TX PDU encode/decode into common code (Varun) - Extend iscsit_transport with xmit_pdu, release_cmd, get_rx_pdu, validate_parameters, and get_r2t_ttt for generic ISO offload (Varun) - Initial merge of cxgb iscsi-segment offload target driver (Varun) The bulk of the changes are Chelsio's new driver, along with a number of iscsi-target common code improvements made by Varun + Co along the way" * 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (29 commits) iscsi-target: Fix early sk_data_ready LOGIN_FLAGS_READY race cxgbit: Use type ISCSI_CXGBIT + cxgbit tpg_np attribute iscsi-target: Convert transport drivers to signal rdma_shutdown iscsi-target: Make iscsi_tpg_np driver show/store use generic code tcm_qla2xxx Add SCSI command jammer/discard capability iscsi-target: graceful disconnect on invalid mapping to iovec target: need_to_release is always false, remove redundant check and kfree target: remove sess_kref and ->shutdown_session iscsi-target: remove usage of ->shutdown_session tcm_qla2xxx: introduce a private sess_kref target: make close_session optional target: make ->shutdown_session optional target: remove acl_stop target: consolidate and fix session shutdown cxgbit: add files for cxgbit.ko iscsi-target: export symbols iscsi-target: call complete on conn_logout_comp iscsi-target: clear tx_thread_active iscsi-target: add new offload transport type iscsi-target: use conn_transport->transport_type in text rsp ...
2016-05-13target: enhance and export target_alloc_sgl/target_free_sglChristoph Hellwig
The SRP target driver will need to allocate and chain it's own SGLs soon. For this export target_alloc_sgl, and add a new argument to it so that it can allocate an additional chain entry that doesn't point to a page. Also export transport_free_sgl after renaming it to target_free_sgl to free these SGLs again. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
2016-05-10target: remove sess_kref and ->shutdown_sessionChristoph Hellwig
Both of them are unused now that drivers handle any delayed session shutdown internally. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-05-10target: make close_session optionalChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>