Merged. Thanks. On Fri, Jul 28, 2017 at 8:54 AM, Guan Junxiong <[email protected]> wrote:
> Hi Hannes, > > On 2017/7/28 14:12, Hannes Reinecke wrote: > > On 07/28/2017 03:28 AM, Guan Junxiong wrote: > >> The previous code of path_offline checking was only valid for SCSI > >> device. It returned PATH_UP for other devices and throwed path check- > >> ing to chekers. This patch supplements checking sysfs path state for > >> NVMe/NVMf devices. For example, if NVMe/NVMf path is reconnectting or > >> resetting, we return PATH_PENDING in order to skip current path check- > >> ing and reschedule path checking in the next tick as soon as possible. > >> > >> Signed-off-by: Guan Junxiong <[email protected]> > >> --- > >> libmultipath/discovery.c | 45 ++++++++++++++++++++++++++++++ > +++++---------- > >> 1 file changed, 35 insertions(+), 10 deletions(-) > >> > > Thanks for doing this. > > > >> > > Patch looks good. > > > > Reviewed-by: Hannes Reinecke <[email protected]> > > > Nice to have any review. Thanks. > > > However, I do wonder if we really need a path checker for NVMf once we > > have this. After all, the sysfs attribute reflects that KATO status, > > which pretty much determines if we can send I/O _at all_. > > > > Cheers, > > > > Hannes > > IMO, I think Keep Alive feature is in controller granularity , _not_ > namespace > granularity. A namespace can be detached ( or disabled with nvmetcli tools) > from controller which has many namespaces attached, but the controller > sysfs > state attribute is still "live". Therefor, we do need further path checker > after we know controller is live. > > Refer to the following quoted from NVMe Spec 1.3: > "The Keep Alive feature is used by the host to determine that the > controller > is operational and by the controller to determine that the host is > operational. > The host and controller are operational when each is accessible and able to > issue or execute commands." > > > Regards > Guan > > > . > >
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