On Tue, Feb 06, 2018 at 02:01:05PM -0600, wenxiong wrote:
> On 2018-02-06 10:33, Keith Busch wrote:
> > On Mon, Feb 05, 2018 at 03:49:40PM -0600, [email protected]
> > wrote:
> > > @@ -1189,6 +1183,12 @@ static enum blk_eh_timer_return
> > > nvme_timeout(struct request *req, bool reserved)
> > > struct nvme_command cmd;
> > > u32 csts = readl(dev->bar + NVME_REG_CSTS);
> > >
> > > + /* If PCI error recovery process is happening, we cannot reset or
> > > + * the recovery mechanism will surely fail.
> > > + */
> > > + if (pci_channel_offline(to_pci_dev(dev->dev)))
> > > + return BLK_EH_HANDLED;
> > > +
> >
> > This patch will tell the block layer to complete the request and
> > consider
> > it a success, but it doesn't look like the command actually completed at
> > all. You're going to get data corruption this way, right? Is returning
> > BLK_EH_HANDLED immediately really the right thing to do here?
>
> Hi Ming,
>
> Can you help checking if it is ok if returning BLK_EH_HANDLEDED in this
> case?
Hi Wenxiong,
Looks Keith is correct, and this timed out request will be completed by
block layer and NVMe driver if BLK_EH_HANDLED is returned, but this IO
isn't completed actually, so either data loss(write) or read failure is
caused.
Maybe BLK_EH_RESET_TIMER is fine under this situation.
Thanks,
Ming
On 2018-02-06 19:24, Ming Lei wrote:
> On Tue, Feb 06, 2018 at 02:01:05PM -0600, wenxiong wrote:
>> On 2018-02-06 10:33, Keith Busch wrote:
>> > On Mon, Feb 05, 2018 at 03:49:40PM -0600, [email protected]
>> > wrote:
>> > > @@ -1189,6 +1183,12 @@ static enum blk_eh_timer_return
>> > > nvme_timeout(struct request *req, bool reserved)
>> > > struct nvme_command cmd;
>> > > u32 csts = readl(dev->bar + NVME_REG_CSTS);
>> > >
>> > > + /* If PCI error recovery process is happening, we cannot reset or
>> > > + * the recovery mechanism will surely fail.
>> > > + */
>> > > + if (pci_channel_offline(to_pci_dev(dev->dev)))
>> > > + return BLK_EH_HANDLED;
>> > > +
>> >
>> > This patch will tell the block layer to complete the request and
>> > consider
>> > it a success, but it doesn't look like the command actually completed at
>> > all. You're going to get data corruption this way, right? Is returning
>> > BLK_EH_HANDLED immediately really the right thing to do here?
>>
>> Hi Ming,
>>
>> Can you help checking if it is ok if returning BLK_EH_HANDLEDED in
>> this
>> case?
>
> Hi Wenxiong,
>
> Looks Keith is correct, and this timed out request will be completed by
> block layer and NVMe driver if BLK_EH_HANDLED is returned, but this IO
> isn't completed actually, so either data loss(write) or read failure is
> caused.
>
> Maybe BLK_EH_RESET_TIMER is fine under this situation.
>
> Thanks,
> Ming
>
Hi Ming,
Thanks! I have tried with BLK_EH_RESET_TIMER and EEH recovery works
fine. I am going to resubmit the patch.
Thanks,
Wendy