From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Ewan D. Milne" Subject: Re: [PATCH] lpfc: Fix hard lock up NMI in els timeout handling. Date: Wed, 08 Nov 2017 13:57:14 -0500 Message-ID: <1510167434.4090.238.camel@localhost.localdomain> References: <20171107205902.17352-1-jsmart2021@gmail.com> Reply-To: emilne@redhat.com Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: Received: from mx1.redhat.com ([209.132.183.28]:46248 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751716AbdKHS5Q (ORCPT ); Wed, 8 Nov 2017 13:57:16 -0500 In-Reply-To: <20171107205902.17352-1-jsmart2021@gmail.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: James Smart Cc: linux-scsi@vger.kernel.org, Dick Kennedy , James Smart On Tue, 2017-11-07 at 12:59 -0800, James Smart wrote: > From: Dick Kennedy > > System crashed due to a hard lockup at lpfc_els_timeout_handler+0x128. > > The els ring's txcmplq list is corrupted: the last element in the list > does not point back the the head causing a loop. Issue is the > els processing path for sli4 hbas are using the hbalock instead of > the ring_lock for removing elements from the txcmplq list. > > Use the adapter SLI_REV to determine which lock should be used for > removing iocbqs from the els rings txcmplq. > > note: the future refactoring will address this so that we don't have > this ugly type-based lock code. > > Signed-off-by: Dick Kennedy > Signed-off-by: James Smart > --- > drivers/scsi/lpfc/lpfc_sli.c | 13 ++++++++++--- > 1 file changed, 10 insertions(+), 3 deletions(-) > > diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c > index 1229f58bdd09..c1c7df607604 100644 > --- a/drivers/scsi/lpfc/lpfc_sli.c > +++ b/drivers/scsi/lpfc/lpfc_sli.c > @@ -2732,7 +2732,8 @@ lpfc_sli_process_unsol_iocb(struct lpfc_hba *phba, struct lpfc_sli_ring *pring, > * > * This function looks up the iocb_lookup table to get the command iocb > * corresponding to the given response iocb using the iotag of the > - * response iocb. This function is called with the hbalock held. > + * response iocb. This function is called with the hbalock held > + * for sli3 devices or the ring_lock for sli4 devices. > * This function returns the command iocb object if it finds the command > * iocb else returns NULL. > **/ > @@ -2828,9 +2829,15 @@ lpfc_sli_process_sol_iocb(struct lpfc_hba *phba, struct lpfc_sli_ring *pring, > unsigned long iflag; > > /* Based on the iotag field, get the cmd IOCB from the txcmplq */ > - spin_lock_irqsave(&phba->hbalock, iflag); > + if (phba->sli_rev == LPFC_SLI_REV4) > + spin_lock_irqsave(&pring->ring_lock, iflag); > + else > + spin_lock_irqsave(&phba->hbalock, iflag); > cmdiocbp = lpfc_sli_iocbq_lookup(phba, pring, saveq); > - spin_unlock_irqrestore(&phba->hbalock, iflag); > + if (phba->sli_rev == LPFC_SLI_REV4) > + spin_unlock_irqrestore(&pring->ring_lock, iflag); > + else > + spin_unlock_irqrestore(&phba->hbalock, iflag); > > if (cmdiocbp) { > if (cmdiocbp->iocb_cmpl) { The other callers of lpfc_sli_iocbq_lookup() use the 2 different locks, depending upon the SLI-3/SLI-4 case. Reviewed-by: Ewan D. Milne