kernel.git/drivers/target/target_core_device.c, branch linux-5.4.y

scsi: target: core: Add TMF to tmr_list handling

2024-03-01T12:13:33Z

[ Upstream commit 83ab68168a3d990d5ff39ab030ad5754cbbccb25 ] An abort that is responded to by iSCSI itself is added to tmr_list but does not go to target core. A LUN_RESET that goes through tmr_list takes a refcounter on the abort and waits for completion. However, the abort will be never complete because it was not started in target core. Unable to locate ITT: 0x05000000 on CID: 0 Unable to locate RefTaskTag: 0x05000000 on CID: 0. wait_for_tasks: Stopping tmf LUN_RESET with tag 0x0 ref_task_tag 0x0 i_state 34 t_state ISTATE_PROCESSING refcnt 2 transport_state active,stop,fabric_stop wait for tasks: tmf LUN_RESET with tag 0x0 ref_task_tag 0x0 i_state 34 t_state ISTATE_PROCESSING refcnt 2 transport_state active,stop,fabric_stop ... INFO: task kworker/0:2:49 blocked for more than 491 seconds. task:kworker/0:2 state:D stack: 0 pid: 49 ppid: 2 flags:0x00000800 Workqueue: events target_tmr_work [target_core_mod] Call Trace: __switch_to+0x2c4/0x470 _schedule+0x314/0x1730 schedule+0x64/0x130 schedule_timeout+0x168/0x430 wait_for_completion+0x140/0x270 target_put_cmd_and_wait+0x64/0xb0 [target_core_mod] core_tmr_lun_reset+0x30/0xa0 [target_core_mod] target_tmr_work+0xc8/0x1b0 [target_core_mod] process_one_work+0x2d4/0x5d0 worker_thread+0x78/0x6c0 To fix this, only add abort to tmr_list if it will be handled by target core. Signed-off-by: Dmitry Bogdanov Link: https://lore.kernel.org/r/20240111125941.8688-1-d.bogdanov@yadro.com Reviewed-by: Mike Christie Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin

scsi: target: core: Fix deadlock due to recursive locking

2023-10-10T19:46:43Z

[ Upstream commit a154f5f643c6ecddd44847217a7a3845b4350003 ] The following call trace shows a deadlock issue due to recursive locking of mutex "device_mutex". First lock acquire is in target_for_each_device() and second in target_free_device(). PID: 148266 TASK: ffff8be21ffb5d00 CPU: 10 COMMAND: "iscsi_ttx" #0 [ffffa2bfc9ec3b18] __schedule at ffffffffa8060e7f #1 [ffffa2bfc9ec3ba0] schedule at ffffffffa8061224 #2 [ffffa2bfc9ec3bb8] schedule_preempt_disabled at ffffffffa80615ee #3 [ffffa2bfc9ec3bc8] __mutex_lock at ffffffffa8062fd7 #4 [ffffa2bfc9ec3c40] __mutex_lock_slowpath at ffffffffa80631d3 #5 [ffffa2bfc9ec3c50] mutex_lock at ffffffffa806320c #6 [ffffa2bfc9ec3c68] target_free_device at ffffffffc0935998 [target_core_mod] #7 [ffffa2bfc9ec3c90] target_core_dev_release at ffffffffc092f975 [target_core_mod] #8 [ffffa2bfc9ec3ca0] config_item_put at ffffffffa79d250f #9 [ffffa2bfc9ec3cd0] config_item_put at ffffffffa79d2583 #10 [ffffa2bfc9ec3ce0] target_devices_idr_iter at ffffffffc0933f3a [target_core_mod] #11 [ffffa2bfc9ec3d00] idr_for_each at ffffffffa803f6fc #12 [ffffa2bfc9ec3d60] target_for_each_device at ffffffffc0935670 [target_core_mod] #13 [ffffa2bfc9ec3d98] transport_deregister_session at ffffffffc0946408 [target_core_mod] #14 [ffffa2bfc9ec3dc8] iscsit_close_session at ffffffffc09a44a6 [iscsi_target_mod] #15 [ffffa2bfc9ec3df0] iscsit_close_connection at ffffffffc09a4a88 [iscsi_target_mod] #16 [ffffa2bfc9ec3df8] finish_task_switch at ffffffffa76e5d07 #17 [ffffa2bfc9ec3e78] iscsit_take_action_for_connection_exit at ffffffffc0991c23 [iscsi_target_mod] #18 [ffffa2bfc9ec3ea0] iscsi_target_tx_thread at ffffffffc09a403b [iscsi_target_mod] #19 [ffffa2bfc9ec3f08] kthread at ffffffffa76d8080 #20 [ffffa2bfc9ec3f50] ret_from_fork at ffffffffa8200364 Fixes: 36d4cb460bcb ("scsi: target: Avoid that EXTENDED COPY commands trigger lock inversion") Signed-off-by: Junxiao Bi Link: https://lore.kernel.org/r/20230918225848.66463-1-junxiao.bi@oracle.com Reviewed-by: Mike Christie Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin

scsi: target: Fix ordered tag handling

2021-11-26T09:47:16Z

[ Upstream commit ed1227e080990ffec5bf39006ec8a57358e6689a ] This patch fixes the following bugs: 1. If there are multiple ordered cmds queued and multiple simple cmds completing, target_restart_delayed_cmds() could be called on different CPUs and each instance could start a ordered cmd. They could then run in different orders than they were queued. 2. target_restart_delayed_cmds() and target_handle_task_attr() can race where: 1. target_handle_task_attr() has passed the simple_cmds == 0 check. 2. transport_complete_task_attr() then decrements simple_cmds to 0. 3. transport_complete_task_attr() runs target_restart_delayed_cmds() and it does not see any cmds on the delayed_cmd_list. 4. target_handle_task_attr() adds the cmd to the delayed_cmd_list. The cmd will then end up timing out. 3. If we are sent > 1 ordered cmds and simple_cmds == 0, we can execute them out of order, because target_handle_task_attr() will hit that simple_cmds check first and return false for all ordered cmds sent. 4. We run target_restart_delayed_cmds() after every cmd completion, so if there is more than 1 simple cmd running, we start executing ordered cmds after that first cmd instead of waiting for all of them to complete. 5. Ordered cmds are not supposed to start until HEAD OF QUEUE and all older cmds have completed, and not just simple. 6. It's not a bug but it doesn't make sense to take the delayed_cmd_lock for every cmd completion when ordered cmds are almost never used. Just replacing that lock with an atomic increases IOPs by up to 10% when completions are spread over multiple CPUs and there are multiple sessions/ mqs/thread accessing the same device. This patch moves the queued delayed handling to a per device work to serialze the cmd executions for each device and adds a new counter to track HEAD_OF_QUEUE and SIMPLE cmds. We can then check the new counter to determine when to run the work on the completion path. Link: https://lore.kernel.org/r/20210930020422.92578-3-michael.christie@oracle.com Signed-off-by: Mike Christie Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin

scsi: target: core: Do not overwrite CDB byte 1

2019-10-18T01:40:25Z

passthrough_parse_cdb() - used by TCMU and PSCSI - attepts to reset the LUN field of SCSI-2 CDBs (bits 5,6,7 of byte 1). The current code is wrong as for newer commands not having the LUN field it overwrites relevant command bits (e.g. for SECURITY PROTOCOL IN / OUT). We think this code was unnecessary from the beginning or at least it is no longer useful. So we remove it entirely. Link: https://lore.kernel.org/r/12498eab-76fd-eaad-1316-c2827badb76a@ts.fujitsu.com Signed-off-by: Bodo Stroesser Reviewed-by: Bart Van Assche Reviewed-by: Hannes Reinecke Signed-off-by: Martin K. Petersen

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156

2019-05-30T18:26:35Z

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1334 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Reviewed-by: Richard Fontana Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de Signed-off-by: Greg Kroah-Hartman

scsi: target/core: Fix a race condition in the LUN lookup code

2019-04-13T00:20:05Z

The rcu_dereference(deve->se_lun) expression occurs twice in the LUN lookup functions. Since these expressions are not serialized against deve->se_lun assignments each of these expressions may yield a different result. Avoid that the wrong LUN pointer is stored in se_cmd by reading deve->se_lun only once. Cc: Mike Christie Cc: Christoph Hellwig Cc: Hannes Reinecke Cc: Nicholas Bellinger Fixes: 29a05deebf6c ("target: Convert se_node_acl->device_list[] to RCU hlist") # v4.10 Signed-off-by: Bart Van Assche Signed-off-by: Martin K. Petersen

scsi: target/iscsi: Convert comments about locking into runtime checks

2019-02-05T02:33:08Z

Cc: Nicholas Bellinger Cc: Mike Christie Cc: Christoph Hellwig Cc: Hannes Reinecke Signed-off-by: Bart Van Assche Signed-off-by: Martin K. Petersen

scsi: target: perform t10_wwn ID initialisation in target_alloc_device()

2018-12-08T02:54:33Z

Initialise the t10_wwn vendor, model and revision defaults when a device is allocated instead of when it's enabled. This ensures that custom vendor or model strings set prior to enablement are not later overwritten with default values. The TRANSPORT_FLAG_PASSTHROUGH conditional can be dropped for the following reasons: - target_core_pscsi overwrites the defaults in the pscsi_configure_device() callback. + the contents is then only used for ConfigFS via $pscsi_dev/statistics/scsi_lu/vend, etc. - target_core_user doesn't touch the defaults, nor are they used for anything outside of ConfigFS. Signed-off-by: David Disseldorp Reviewed-by: Roman Bolshakov Signed-off-by: Martin K. Petersen

scsi: target: consistently null-terminate t10_wwn strings

2018-12-08T02:54:33Z

In preparation for supporting user provided vendor strings, add an extra byte to the vendor, model and revision arrays in struct t10_wwn. This ensures that the full INQUIRY data can be carried in the arrays along with a null-terminator. Change a number of array readers and writers so that they account for explicit null-termination: - The pscsi_set_inquiry_info() and emulate_model_alias_store() codepaths don't currently explicitly null-terminate; fix this. - Existing t10_wwn field dumps use for-loops which step over null-terminators for right-padding. + Use printf with width specifiers instead. Signed-off-by: David Disseldorp Reviewed-by: Roman Bolshakov Signed-off-by: Martin K. Petersen

scsi: target/core: Use system workqueues for TMF

2018-12-08T02:20:07Z

A quote from SAM-5: "The order in which task management requests are processed is not specified by the SCSI architecture model. The SCSI architecture model does not require in-order delivery of such task management requests or processing by the task manager in the order received. To guarantee the processing order of task management requests referencing sent to a specific logical unit, an application client should not have more than one such task management request pending to that logical unit." This means that it is safe to use the system workqueues instead of tmr_wq for processing TMFs. An intended side effect of this patch is that it enables concurrent processing of TMFs. Reviewed-by: Christoph Hellwig Cc: Nicholas Bellinger Cc: Mike Christie Cc: David Disseldorp Cc: Hannes Reinecke Signed-off-by: Bart Van Assche Signed-off-by: Martin K. Petersen