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From:   Daniel Wagner <dwagner@suse.de>
To:     linux-nvme@lists.infradead.org
Cc:     linux-kernel@vger.kernel.org, linux-block@vger.kernel.org,
        Chaitanya Kulkarni <kch@nvidia.com>,
        Shin'ichiro Kawasaki <shinichiro@fastmail.com>,
        Sagi Grimberg <sagi@grimberg.me>,
        Hannes Reinecke <hare@suse.de>,
        James Smart <jsmart2021@gmail.com>,
        Daniel Wagner <dwagner@suse.de>
Subject: [PATCH v2 0/5] nvme-fc: Fix blktests hangers
Date:   Tue, 20 Jun 2023 15:37:06 +0200
Message-ID: <20230620133711.22840-1-dwagner@suse.de>
MIME-Version: 1.0
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With the additinal 3 patches and the blktests changes [1] I am able to run the
tests in a loop for a while without failures. I expect there are more problems
hidden but with these changes the first milesone is reached.

The first new patch is actually one from a previous attempt. It addresses the
problem in unloading path where we dont make any progress more [2].

The next two patches change the existing initial connection attempt of FC to
a synchronous one. Without this the auth test fail [3].

Daniel


[1] https://lore.kernel.org/linux-nvme/20230620132703.20648-1-dwagner@suse.de/
[2] https://lore.kernel.org/linux-nvme/20230418130159.11075-1-dwagner@suse.de/
[3] https://lore.kernel.org/linux-nvme/j4w7724skjsapgtp6wtll5fgsb4adhpfdtrif52lhc7iql4inf@3mu2gbjrrtcs/

changes:

v2:
  - added RBs
  - added new patches

v1:
  - https://lore.kernel.org/linux-nvme/20230615094356.14878-1-dwagner@suse.de/ 


Initial cover letter:

A couple more fixes to enable blktests for the fc transport.

1) Another module unloading hanger which can be triggered with
   the nvme/048 tests:

   run blktests nvme/048 at 2023-06-06 13:04:49
   nvmet: adding nsid 1 to subsystem blktests-subsystem-1
   nvme nvme2: NVME-FC{0}: create association : host wwpn 0x20001100aa000002  rport wwpn 0x20001100aa000001: NQN "blktests-subsystem-1"
   (NULL device *): {0:0} Association created
   [478] nvmet: ctrl 1 start keep-alive timer for 1 secs
   [478] nvmet: check nqn.2014-08.org.nvmexpress:uuid:3d0c3f5d-cb37-4bc4-af29-2168953bfc0a
   [478] nvmet: nvmet_setup_dhgroup: ctrl 1 selecting dhgroup 0
   [478] nvmet: No authentication provided
   nvmet: creating nvm controller 1 for subsystem blktests-subsystem-1 for NQN nqn.2014-08.org.nvmexpress:uuid:3d0c3f5d-cb37-4bc4-af29-2168953bfc0a.
   [478] nvmet: adding queue 1 to ctrl 1.
   [407] nvmet: adding queue 2 to ctrl 1.
   [6549] nvmet: adding queue 3 to ctrl 1.
   [1760] nvmet: adding queue 4 to ctrl 1.
   nvme nvme2: NVME-FC{0}: controller connect complete
   nvme nvme2: NVME-FC{0}: new ctrl: NQN "blktests-subsystem-1"
   [478] nvmet: ctrl 1 reschedule traffic based keep-alive timer
   [407] nvmet: ctrl 1 update keep-alive timer for 1 secs
   nvme nvme2: NVME-FC{0}: io failed due to lldd error 6
   nvme nvme2: NVME-FC{0}: transport association event: transport detected io error
   nvme nvme2: NVME-FC{0}: resetting controller
   [478] nvmet: ctrl 1 stop keep-alive
   (NULL device *): {0:0} Association deleted
   nvme nvme2: NVME-FC{0}: create association : host wwpn 0x20001100aa000002  rport wwpn 0x20001100aa000001: NQN "blktests-subsystem-1"
   (NULL device *): {0:0} Association freed
   (NULL device *): {0:0} Association created
   (NULL device *): Disconnect LS failed: No Association
   [407] nvmet: ctrl 1 start keep-alive timer for 1 secs
   [407] nvmet: check nqn.2014-08.org.nvmexpress:uuid:3d0c3f5d-cb37-4bc4-af29-2168953bfc0a
   [407] nvmet: nvmet_setup_dhgroup: ctrl 1 selecting dhgroup 0
   [407] nvmet: No authentication provided
   nvmet: creating nvm controller 1 for subsystem blktests-subsystem-1 for NQN nqn.2014-08.org.nvmexpress:uuid:3d0c3f5d-cb37-4bc4-af29-2168953bfc0a.
   nvme nvme2: reconnect: revising io queue count from 4 to 1
   [478] nvmet: adding queue 1 to ctrl 1.
   nvme nvme2: NVME-FC{0}: controller connect complete
   [478] nvmet: ctrl 1 reschedule traffic based keep-alive timer
   [478] nvmet: ctrl 1 update keep-alive timer for 1 secs
   [478] nvmet: ctrl 1 update keep-alive timer for 1 secs
   [6549] nvmet: ctrl 1 update keep-alive timer for 1 secs
   [6549] nvmet: ctrl 1 update keep-alive timer for 1 secs
   [6549] nvmet: ctrl 1 update keep-alive timer for 1 secs
   [6549] nvmet: ctrl 1 update keep-alive timer for 1 secs
   [1760] nvmet: ctrl 1 update keep-alive timer for 1 secs
   [1760] nvmet: ctrl 1 update keep-alive timer for 1 secs
   [1760] nvmet: ctrl 1 update keep-alive timer for 1 secs
   [1760] nvmet: ctrl 1 update keep-alive timer for 1 secs
   [1760] nvmet: ctrl 1 update keep-alive timer for 1 secs
   [1760] nvmet: ctrl 1 update keep-alive timer for 1 secs
   [407] nvmet: ctrl 1 update keep-alive timer for 1 secs
   nvme nvme2: NVME-FC{0}: io failed due to lldd error 6
   nvme nvme2: NVME-FC{0}: transport association event: transport detected io error
   nvme nvme2: NVME-FC{0}: resetting controller
   [478] nvmet: ctrl 1 stop keep-alive
   (NULL device *): {0:0} Association deleted
   (NULL device *): {0:0} Association freed
   (NULL device *): Disconnect LS failed: No Association
   nvme nvme2: NVME-FC{0}: create association : host wwpn 0x20001100aa000002  rport wwpn 0x20001100aa000001: NQN "blktests-subsystem-1"
   (NULL device *): {0:0} Association created
   [1760] nvmet: ctrl 1 start keep-alive timer for 1 secs
   [1760] nvmet: check nqn.2014-08.org.nvmexpress:uuid:3d0c3f5d-cb37-4bc4-af29-2168953bfc0a
   [1760] nvmet: nvmet_setup_dhgroup: ctrl 1 selecting dhgroup 0
   [1760] nvmet: No authentication provided
   nvmet: creating nvm controller 1 for subsystem blktests-subsystem-1 for NQN nqn.2014-08.org.nvmexpress:uuid:3d0c3f5d-cb37-4bc4-af29-2168953bfc0a.
   nvme nvme2: reconnect: revising io queue count from 1 to 4
   [478] nvmet: adding queue 1 to ctrl 1.
   [407] nvmet: adding queue 2 to ctrl 1.
   [6549] nvmet: adding queue 3 to ctrl 1.
   [1760] nvmet: adding queue 4 to ctrl 1.
   nvme nvme2: NVME-FC{0}: controller connect complete
   [1760] nvmet: ctrl 1 reschedule traffic based keep-alive timer
   [478] nvmet: ctrl 1 update keep-alive timer for 1 secs
   [478] nvmet: ctrl 1 update keep-alive timer for 1 secs
   [478] nvmet: ctrl 1 update keep-alive timer for 1 secs
   [478] nvmet: ctrl 1 update keep-alive timer for 1 secs
   [1760] nvmet: ctrl 1 update keep-alive timer for 1 secs
   [6549] nvmet: ctrl 1 update keep-alive timer for 1 secs
   [1760] nvmet: ctrl 1 update keep-alive timer for 1 secs
   [6549] nvmet: ctrl 1 update keep-alive timer for 1 secs
   [1760] nvmet: ctrl 1 update keep-alive timer for 1 secs
   [1760] nvmet: ctrl 1 update keep-alive timer for 1 secs
   [6549] nvmet: ctrl 1 update keep-alive timer for 1 secs
   [1760] nvmet: ctrl 1 update keep-alive timer for 1 secs
   [6549] nvmet: ctrl 1 update keep-alive timer for 1 secs
   nvme nvme2: Removing ctrl: NQN "blktests-subsystem-1"
   [407] nvmet: ctrl 1 stop keep-alive
   (NULL device *): {0:0} Association deleted
   (NULL device *): {0:0} Association freed
   (NULL device *): Disconnect LS failed: No Association
   nvme_fc: nvme_fc_exit_module: waiting for ctlr deletes
   BTRFS info (device vda2): qgroup scan completed (inconsistency flag cleared)
   INFO: task modprobe:11758 blocked for more than 491 seconds.
         Tainted: G        W          6.4.0-rc2+ #3
   "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
   task:modprobe        state:D stack:0     pid:11758 ppid:11585  flags:0x00004002
   Call Trace:
    <TASK>
    __schedule+0x17b5/0x4870
    ? finish_lock_switch+0x8f/0x120
    ? finish_task_switch+0x17f/0x5c0
    ? __sched_text_start+0x10/0x10
    ? __schedule+0x17bd/0x4870
    ? do_raw_spin_trylock+0xc9/0x1f0
    schedule+0xe6/0x1e0
    schedule_timeout+0x7e/0x1e0
    ? __cfi_schedule_timeout+0x10/0x10
    ? do_raw_spin_trylock+0xc9/0x1f0
    ? __cfi_lock_release+0x10/0x10
    ? do_raw_spin_unlock+0x116/0x8a0
    wait_for_common+0x377/0x600
    ? wait_for_completion+0x30/0x30
    cleanup_module+0x222/0x240 [nvme_fc bda1ef6f83d00208ba257c5d0ac34dd6bdb58bf9]
    __se_sys_delete_module+0x388/0x550
    ? __x64_sys_delete_module+0x50/0x50
    ? task_work_run+0x236/0x290
    ? syscall_enter_from_user_mode+0x2e/0x210
    do_syscall_64+0x6e/0xa0
    ? syscall_exit_to_user_mode+0x5e/0x220
    ? do_syscall_64+0x7d/0xa0
    ? syscall_exit_to_user_mode+0x5e/0x220
    ? do_syscall_64+0x7d/0xa0
    ? syscall_exit_to_user_mode+0x5e/0x220
    ? do_syscall_64+0x7d/0xa0
    entry_SYSCALL_64_after_hwframe+0x72/0xdc
   RIP: 0033:0x7fa80811aebb
   RSP: 002b:00007fff80ea0a88 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
   RAX: ffffffffffffffda RBX: 000055a0b5acf1f0 RCX: 00007fa80811aebb
   RDX: 0000000000000000 RSI: 0000000000000800 RDI: 000055a0b5acf258
   RBP: 0000000000000000 R08: 1999999999999999 R09: 0000000000000000
   R10: 00007fa808193ac0 R11: 0000000000000206 R12: 00007fff80ea0ad0
   R13: 000055a0b5acf1f0 R14: 0000000000000000 R15: 0000000000000000
    </TASK>
 

2) When executing blktests nvme/030 in a tight loop, I was able to
   reproduce a different hanger. In this case the ->done() function
   was never executed on the host fc side. It turns out we didn't
   enqueue work items correctly and thus would only process one
   work item.

   run blktests nvme/030 at 2023-06-13 14:03:52
   nvmet: adding nsid 1 to subsystem blktests-subsystem-1
   nvme nvme2: NVME-FC{0}: create association : host wwpn 0x20001100aa000002  rport wwpn 0x20001100aa000001: NQN "nqn.2014-08.org.nvmexpress.discovery"
   (NULL device *): {0:0} Association created
   [23733] nvmet: ctrl 1 start keep-alive timer for 120 secs
   nvmet: creating discovery controller 1 for subsystem nqn.2014-08.org.nvmexpress.discovery for NQN nqn.2014-08.org.nvmexpress:uuid:242d4a24-2484-4a80-8234-d0169409c5e8.
   nvme nvme2: NVME-FC{0}: controller connect complete
   nvme nvme2: NVME-FC{0}: new ctrl: NQN "nqn.2014-08.org.nvmexpress.discovery"
   nvme nvme2: Removing ctrl: NQN "nqn.2014-08.org.nvmexpress.discovery"
   [23771] nvmet: ctrl 1 stop keep-alive
   nvmet: adding nsid 1 to subsystem blktests-subsystem-2
   (NULL device *): {0:0} Association deleted
   (NULL device *): {0:0} Association freed
   (NULL device *): Disconnect LS failed: No Association
   nvme nvme2: NVME-FC{0}: create association : host wwpn 0x20001100aa000002  rport wwpn 0x20001100aa000001: NQN "nqn.2014-08.org.nvmexpress.discovery"
   (NULL device *): {0:0} Association created
   [27320] nvmet: ctrl 1 start keep-alive timer for 120 secs
   nvmet: creating discovery controller 1 for subsystem nqn.2014-08.org.nvmexpress.discovery for NQN nqn.2014-08.org.nvmexpress:uuid:242d4a24-2484-4a80-8234-d0169409c5e8.
   nvme nvme2: NVME-FC{0}: controller connect complete
   nvme nvme2: NVME-FC{0}: new ctrl: NQN "nqn.2014-08.org.nvmexpress.discovery"
   nvme nvme2: Removing ctrl: NQN "nqn.2014-08.org.nvmexpress.discovery"
   [27320] nvmet: ctrl 1 stop keep-alive
   nvme nvme2: NVME-FC{0}: create association : host wwpn 0x20001100aa000002  rport wwpn 0x20001100aa000001: NQN "nqn.2014-08.org.nvmexpress.discovery"
   (NULL device *): {0:1} Association created
   (NULL device *): {0:0} Association deleted
   (NULL device *): {0:0} Association freed
   (NULL device *): Disconnect LS failed: No Association
   INFO: task kworker/u8:4:102 blocked for more than 491 seconds.
         Tainted: G        W          6.4.0-rc2+ #3
   "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
   task:kworker/u8:4    state:D stack:0     pid:102   ppid:2      flags:0x00004000
   Workqueue: nvme-wq nvme_fc_connect_ctrl_work [nvme_fc]
   Call Trace:
    <TASK>
    __schedule+0x17b5/0x4870
    ? try_to_wake_up+0xb5/0xfc0
    ? __cfi_lock_release+0x10/0x10
    ? __sched_text_start+0x10/0x10
    ? _raw_spin_unlock_irqrestore+0x24/0x50
    ? lock_release+0x2aa/0xd10
    ? wq_worker_sleeping+0x1e/0x200
    schedule+0xe6/0x1e0
    schedule_timeout+0x7e/0x1e0
    ? __cfi_schedule_timeout+0x10/0x10
    ? mark_lock+0x94/0x340
    ? lockdep_hardirqs_on_prepare+0x2aa/0x5e0
    wait_for_common+0x377/0x600
    ? queue_work_on+0x57/0xa0
    ? wait_for_completion+0x30/0x30
    nvme_fc_connect_ctrl_work+0x7dc/0x1a80 [nvme_fc 39e2bf78272df3a610fb1f9884513e99038af746]
    process_one_work+0x80f/0xfb0
    ? rescuer_thread+0x1130/0x1130
    ? do_raw_spin_trylock+0xc9/0x1f0
    ? lock_acquired+0x310/0x9a0
    ? worker_thread+0xd5e/0x1260
    worker_thread+0xbde/0x1260
    kthread+0x25d/0x2f0
    ? __cfi_worker_thread+0x10/0x10
    ? __cfi_kthread+0x10/0x10
    ret_from_fork+0x29/0x50
    </TASK>
 
Daniel Wagner (5):
  nvme-fc: Do not wait in vain when unloading module
  nvme-fcloop: queue work items correctly
  nvmet-fcloop: Remove remote port from list when unlinking
  nvme-fc: Make initial connect attempt synchronous
  nvme-fc: do no free ctrl opts

 drivers/nvme/host/fc.c       | 43 ++++++++++++++++++------------------
 drivers/nvme/target/fcloop.c | 15 +++++--------
 2 files changed, 27 insertions(+), 31 deletions(-)

-- 
2.41.0