[PATCH AUTOSEL 4.19 1/2] scsi: target: core: Add TMF to tmr_list handling

From: Sasha Levin
Date: Mon Jan 29 2024 - 13:46:56 EST


From: Dmitry Bogdanov <d.bogdanov@xxxxxxxxx>

[ 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 <d.bogdanov@xxxxxxxxx>
Link: https://lore.kernel.org/r/20240111125941.8688-1-d.bogdanov@xxxxxxxxx
Reviewed-by: Mike Christie <michael.christie@xxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/target/target_core_device.c | 5 -----
drivers/target/target_core_transport.c | 4 ++++
2 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c
index a23dcbe79e14..3ed43a5f1fd3 100644
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -164,7 +164,6 @@ int transport_lookup_tmr_lun(struct se_cmd *se_cmd, u64 unpacked_lun)
struct se_session *se_sess = se_cmd->se_sess;
struct se_node_acl *nacl = se_sess->se_node_acl;
struct se_tmr_req *se_tmr = se_cmd->se_tmr_req;
- unsigned long flags;

rcu_read_lock();
deve = target_nacl_find_deve(nacl, unpacked_lun);
@@ -195,10 +194,6 @@ int transport_lookup_tmr_lun(struct se_cmd *se_cmd, u64 unpacked_lun)
se_cmd->se_dev = rcu_dereference_raw(se_lun->lun_se_dev);
se_tmr->tmr_dev = rcu_dereference_raw(se_lun->lun_se_dev);

- spin_lock_irqsave(&se_tmr->tmr_dev->se_tmr_lock, flags);
- list_add_tail(&se_tmr->tmr_list, &se_tmr->tmr_dev->dev_tmr_list);
- spin_unlock_irqrestore(&se_tmr->tmr_dev->se_tmr_lock, flags);
-
return 0;
}
EXPORT_SYMBOL(transport_lookup_tmr_lun);
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 64481a3a34d4..f8ba730fa1cf 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -3463,6 +3463,10 @@ int transport_generic_handle_tmr(
unsigned long flags;
bool aborted = false;

+ spin_lock_irqsave(&cmd->se_dev->se_tmr_lock, flags);
+ list_add_tail(&cmd->se_tmr_req->tmr_list, &cmd->se_dev->dev_tmr_list);
+ spin_unlock_irqrestore(&cmd->se_dev->se_tmr_lock, flags);
+
spin_lock_irqsave(&cmd->t_state_lock, flags);
if (cmd->transport_state & CMD_T_ABORTED) {
aborted = true;
--
2.43.0