From 50e3f871fb20a9bb644743e2986e8f50f98a25bc Mon Sep 17 00:00:00 2001 From: James Smart Date: Tue, 12 Mar 2019 16:30:05 -0700 Subject: [PATCH] scsi: lpfc: Resolve irq-unsafe lockdep heirarchy warning in lpfc_io_free 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); 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 Signed-off-by: Dick Kennedy Signed-off-by: James Smart Signed-off-by: Martin K. Petersen --- 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 7fcdaed3fa94..9c266bd142cd 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); } /** -- 2.30.2