| Message ID | 20211019152129.16558-1-brking@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | ibmvfc: Fixup duplicate response detection | expand |
On 10/19/21 8:21 AM, Brian King wrote: > Commit a264cf5e81c7 ("scsi: ibmvfc: Fix command state accounting and stale response detection") > introduced a regression in detecting duplicate responses. This was observed > in test where a command was sent to the VIOS and completed before > ibmvfc_send_event set the active flag to 1, which resulted in the > atomic_dec_if_positive call in ibmvfc_handle_crq thinking this was a > duplicate response, which resulted in scsi_done not getting called, so we > then hit a scsi command timeout for this command once the timeout expires. > This simply ensures the active flag gets set prior to making the hcall to > send the command to the VIOS, in order to close this window. > > Fixes: a264cf5e81c7 ("scsi: ibmvfc: Fix command state accounting and stale response detection") > Cc: stable@vger.kernel.org > Signed-off-by: Brian King <brking@linux.vnet.ibm.com> Acked-by: Tyrel Datwyler <tyreld@linux.ibm.com> > --- > drivers/scsi/ibmvscsi/ibmvfc.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c > index a4b0a12f8a97..d0eab5700dc5 100644 > --- a/drivers/scsi/ibmvscsi/ibmvfc.c > +++ b/drivers/scsi/ibmvscsi/ibmvfc.c > @@ -1696,6 +1696,7 @@ static int ibmvfc_send_event(struct ibmvfc_event *evt, > > spin_lock_irqsave(&evt->queue->l_lock, flags); > list_add_tail(&evt->queue_list, &evt->queue->sent); > + atomic_set(&evt->active, 1); > > mb(); > > @@ -1710,6 +1711,7 @@ static int ibmvfc_send_event(struct ibmvfc_event *evt, > be64_to_cpu(crq_as_u64[1])); > > if (rc) { > + atomic_set(&evt->active, 0); > list_del(&evt->queue_list); > spin_unlock_irqrestore(&evt->queue->l_lock, flags); > del_timer(&evt->timer); > @@ -1737,7 +1739,6 @@ static int ibmvfc_send_event(struct ibmvfc_event *evt, > > evt->done(evt); > } else { > - atomic_set(&evt->active, 1); > spin_unlock_irqrestore(&evt->queue->l_lock, flags); > ibmvfc_trc_start(evt); > } >
On Tue, 19 Oct 2021 10:21:29 -0500, Brian King wrote: > Commit a264cf5e81c7 ("scsi: ibmvfc: Fix command state accounting and stale response detection") > introduced a regression in detecting duplicate responses. This was observed > in test where a command was sent to the VIOS and completed before > ibmvfc_send_event set the active flag to 1, which resulted in the > atomic_dec_if_positive call in ibmvfc_handle_crq thinking this was a > duplicate response, which resulted in scsi_done not getting called, so we > then hit a scsi command timeout for this command once the timeout expires. > This simply ensures the active flag gets set prior to making the hcall to > send the command to the VIOS, in order to close this window. > > [...] Applied to 5.15/scsi-fixes, thanks! [1/1] ibmvfc: Fixup duplicate response detection https://git.kernel.org/mkp/scsi/c/e20f80b9b163
diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c index a4b0a12f8a97..d0eab5700dc5 100644 --- a/drivers/scsi/ibmvscsi/ibmvfc.c +++ b/drivers/scsi/ibmvscsi/ibmvfc.c @@ -1696,6 +1696,7 @@ static int ibmvfc_send_event(struct ibmvfc_event *evt, spin_lock_irqsave(&evt->queue->l_lock, flags); list_add_tail(&evt->queue_list, &evt->queue->sent); + atomic_set(&evt->active, 1); mb(); @@ -1710,6 +1711,7 @@ static int ibmvfc_send_event(struct ibmvfc_event *evt, be64_to_cpu(crq_as_u64[1])); if (rc) { + atomic_set(&evt->active, 0); list_del(&evt->queue_list); spin_unlock_irqrestore(&evt->queue->l_lock, flags); del_timer(&evt->timer); @@ -1737,7 +1739,6 @@ static int ibmvfc_send_event(struct ibmvfc_event *evt, evt->done(evt); } else { - atomic_set(&evt->active, 1); spin_unlock_irqrestore(&evt->queue->l_lock, flags); ibmvfc_trc_start(evt); }
Commit a264cf5e81c7 ("scsi: ibmvfc: Fix command state accounting and stale response detection") introduced a regression in detecting duplicate responses. This was observed in test where a command was sent to the VIOS and completed before ibmvfc_send_event set the active flag to 1, which resulted in the atomic_dec_if_positive call in ibmvfc_handle_crq thinking this was a duplicate response, which resulted in scsi_done not getting called, so we then hit a scsi command timeout for this command once the timeout expires. This simply ensures the active flag gets set prior to making the hcall to send the command to the VIOS, in order to close this window. Fixes: a264cf5e81c7 ("scsi: ibmvfc: Fix command state accounting and stale response detection") Cc: stable@vger.kernel.org Signed-off-by: Brian King <brking@linux.vnet.ibm.com> --- drivers/scsi/ibmvscsi/ibmvfc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)