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: 36d4cb460b ("scsi: target: Avoid that EXTENDED COPY commands trigger lock inversion")
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Link: https://lore.kernel.org/r/20230918225848.66463-1-junxiao.bi@oracle.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
a154f5f643