A patch in the 12.2.0.0 set caused a new lockdep warning:
WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected
5.0.0-rc8-next-20190301-dbg+ #1 Not tainted
Possible interrupt unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&(&qp->io_buf_list_put_lock)->rlock);
local_irq_disable();
lock(&(&phba->hbalock)->rlock);
lock(&(&qp->io_buf_list_put_lock)->rlock);
<Interrupt>
lock(&(&phba->hbalock)->rlock);
see: https://www.spinics.net/lists/linux-scsi/msg128389.html
In summary, the new patch added taking the io_buf_list_put_lock
while under an irq-disabled hbalock. This created a lock heirarchy
dependent upon irq being disabled, and there are paths that take
the io_buf_list_put_lock without disabling irq.
Looking at the lpfc_io_free routine, which is where the new heirarchy
was introduced, there is no reason to be taking out the hbalock and
raising irq, as the functionality is replaced by the io_buf_list_xxx
locks.
Resolve by removing the hbalock/irq calls in lpfc_io_free.
Fixes: 5e5b511d8bfa ("scsi: lpfc: Partition XRI buffer list across Hardware
Queues")
Reported-by: Bart Van Assche <[email protected]>
Signed-off-by: Dick Kennedy <[email protected]>
Signed-off-by: James Smart <[email protected]>
---
drivers/scsi/lpfc/lpfc_init.c | 4 ----
1 file changed, 4 deletions(-)
diff --git a/drivers/scsi/lpfc/lpfc_init.c b/drivers/scsi/lpfc/lpfc_init.c
index 707dbe7a8d15..3e9cc06c3cff 100644
--- a/drivers/scsi/lpfc/lpfc_init.c
+++ b/drivers/scsi/lpfc/lpfc_init.c
@@ -3611,8 +3611,6 @@ lpfc_io_free(struct lpfc_hba *phba)
struct lpfc_sli4_hdw_queue *qp;
int idx;
- spin_lock_irq(&phba->hbalock);
-
for (idx = 0; idx < phba->cfg_hdw_queue; idx++) {
qp = &phba->sli4_hba.hdwq[idx];
/* Release all the lpfc_nvme_bufs maintained by this host. */
@@ -3642,8 +3640,6 @@ lpfc_io_free(struct lpfc_hba *phba)
}
spin_unlock(&qp->io_buf_list_get_lock);
}
-
- spin_unlock_irq(&phba->hbalock);
}
/**
--
2.13.7
