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target: Invoke release_cmd() callback without holding a spinlock

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@sandisk.com>
Acked-by: Joern Engel <joern@logfs.org>
Reviewed-by: Andy Grover <agrover@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
hifive-unleashed-5.1
Bart Van Assche 2015-10-22 15:57:04 -07:00 committed by Nicholas Bellinger
parent 057085e522
commit 9ff9d15edd
2 changed files with 12 additions and 7 deletions

View File

@ -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);

View File

@ -2509,23 +2509,24 @@ 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);
}
@ -2541,8 +2542,7 @@ 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);