[ Upstream commit 50e3f871fb20a9bb644743e2986e8f50f98a25bc ]
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 bvanassche@acm.org Signed-off-by: Dick Kennedy dick.kennedy@broadcom.com Signed-off-by: James Smart jsmart2021@gmail.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 89a0c2bdb6a15..46e155d1fa155 100644 --- a/drivers/scsi/lpfc/lpfc_init.c +++ b/drivers/scsi/lpfc/lpfc_init.c @@ -3618,8 +3618,6 @@ 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. */ @@ -3649,8 +3647,6 @@ lpfc_io_free(struct lpfc_hba *phba) } spin_unlock(&qp->io_buf_list_get_lock); } - - spin_unlock_irq(&phba->hbalock); }
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