This patch fixes the following kernel warning because it avoids that
IRQs are disabled while ft_release_cmd() is invoked (fc_seq_set_resp()
invokes spin_unlock_bh()):
WARNING: CPU: 3 PID: 117 at kernel/softirq.c:150 __local_bh_enable_ip+0xaa/0x110()
Call Trace:
[<ffffffff814f71eb>] dump_stack+0x4f/0x7b
[<ffffffff8105e56a>] warn_slowpath_common+0x8a/0xc0
[<ffffffff8105e65a>] warn_slowpath_null+0x1a/0x20
[<ffffffff81062b2a>] __local_bh_enable_ip+0xaa/0x110
[<ffffffff814ff229>] _raw_spin_unlock_bh+0x39/0x40
[<ffffffffa03a7f94>] fc_seq_set_resp+0xe4/0x100 [libfc]
[<ffffffffa02e604a>] ft_free_cmd+0x4a/0x90 [tcm_fc]
[<ffffffffa02e6972>] ft_release_cmd+0x12/0x20 [tcm_fc]
[<ffffffffa042bd66>] target_release_cmd_kref+0x56/0x90 [target_core_mod]
[<ffffffffa042caf0>] target_put_sess_cmd+0xc0/0x110 [target_core_mod]
[<ffffffffa042cb81>] transport_release_cmd+0x41/0x70 [target_core_mod]
[<ffffffffa042d975>] transport_generic_free_cmd+0x35/0x420 [target_core_mod]
Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxxxxxx>
Acked-by: Joern Engel <joern@xxxxxxxxx>
Reviewed-by: Andy Grover <agrover@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Hannes Reinecke <hare@xxxxxxx>
Cc: Sagi Grimberg <sagig@xxxxxxxxxxxx>
---
drivers/target/target_core_tmr.c | 7 ++++++-
drivers/target/target_core_transport.c | 12 ++++++------
2 files changed, 12 insertions(+), 7 deletions(-)
diff --git a/drivers/target/target_core_tmr.c b/drivers/target/target_core_tmr.c
index 7137042..fcdcb11 100644
--- a/drivers/target/target_core_tmr.c
+++ b/drivers/target/target_core_tmr.c
@@ -130,6 +130,9 @@ void core_tmr_abort_task(
if (tmr->ref_task_tag != ref_tag)
continue;
+ if (!kref_get_unless_zero(&se_cmd->cmd_kref))
+ continue;
+
printk("ABORT_TASK: Found referenced %s task_tag: %llu\n",
se_cmd->se_tfo->get_fabric_name(), ref_tag);
@@ -139,13 +142,15 @@ void core_tmr_abort_task(
" skipping\n", ref_tag);
spin_unlock(&se_cmd->t_state_lock);
spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
+
+ target_put_sess_cmd(se_cmd);
+
goto out;
}
se_cmd->transport_state |= CMD_T_ABORTED;
spin_unlock(&se_cmd->t_state_lock);
list_del_init(&se_cmd->se_cmd_list);
- kref_get(&se_cmd->cmd_kref);
spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
cancel_work_sync(&se_cmd->work);
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index eae4924..7f4d3ac 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -2507,23 +2507,24 @@ out:
EXPORT_SYMBOL(target_get_sess_cmd);
static void target_release_cmd_kref(struct kref *kref)
- __releases(&se_cmd->se_sess->sess_cmd_lock)
{
struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
struct se_session *se_sess = se_cmd->se_sess;
+ unsigned long flags;
+ spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
if (list_empty(&se_cmd->se_cmd_list)) {
- spin_unlock(&se_sess->sess_cmd_lock);
+ spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
se_cmd->se_tfo->release_cmd(se_cmd);
return;
}
if (se_sess->sess_tearing_down && se_cmd->cmd_wait_set) {
- spin_unlock(&se_sess->sess_cmd_lock);
+ spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
complete(&se_cmd->cmd_wait_comp);
return;
}
list_del(&se_cmd->se_cmd_list);
- spin_unlock(&se_sess->sess_cmd_lock);
+ spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
se_cmd->se_tfo->release_cmd(se_cmd);
}
@@ -2539,8 +2540,7 @@ int target_put_sess_cmd(struct se_cmd *se_cmd)
se_cmd->se_tfo->release_cmd(se_cmd);
return 1;
}
- return kref_put_spinlock_irqsave(&se_cmd->cmd_kref, target_release_cmd_kref,
- &se_sess->sess_cmd_lock);
+ return kref_put(&se_cmd->cmd_kref, target_release_cmd_kref);
}
EXPORT_SYMBOL(target_put_sess_cmd);
--
2.1.4
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