Re: [PATCH v3] scsi: libsas: Fix set zero-address when device-type != NO_DEVICE

[yangxingui]

Hi John,

On 2023/11/17 0:54, John Garry wrote:
> On 16/11/2023 13:45, yangxingui wrote:
> > > I think that patch title can be improved, but I would need to know 
> > > more about the problem before suggesting an improvement.
> > How about "Fix port add phy failed" ?
> > > > Firstly, when ex_phy is added to the parent port, ex_phy->port is 
> > > > not set.
> > >
> > > That seems correct, but why mention this now?
> > >
> > > > As a result, sas_port_delete_phy() won't be called in
> > > > sas_unregister_devs_sas_addr(), and although ex_phy's sas_address is 
> > > > zero,
> > > > it is not deleted from the parent port's phy_list.
> > >
> > > I am not sure why you mention this now either. You seem to be 
> > > describing how the problem occurs without actually mentioning what 
> > > the problem is.
> > > ohn
> > > > Secondly, phy->attached_sas_addr will be set to a zero-address when
> > > > phy->linkrate < SAS_LINK_RATE_1_5_GBPS and device-type != NO_DEVICE 
> > > > during
> > > > device registration, such as stp. It will create a new port and all 
> > > > other
> > > > ex_phys whose addresses are zero will be added to the new port in
> > > > sas_ex_get_linkrate(), and it may trigger BUG() as follows:
> > >
> > > I think that it would be better to first mention this crash, i.e. the 
> > > problem, how you recreate it, and then describe how and why it 
> > > happens, and then tell us how you will fix it
> > How about follows:
> >
> > The following processes trigger a BUG(). A new port port-7:7:0 that 
> > created by a new zero-address sata device tries to add phy-7:7:19 had 
> > the same zero-address, but phy-7:7:19 is already part of another port.
>
> I would like to know how to recreate, which gives a lot more context and 
> helps me understand what the problem is.
I have update a new version based on your suggestion.

Thanks,
Xingui
.