Re: [PATCH 2/4] ipmi: Disable sysfs access and requests in maintenance mode

[Corey Minyard <corey@minyard.net>]

On Fri, Aug 08, 2025 at 03:37:51PM -0500, Frederick Lawler wrote:
> Hi Corey,
> 
> On Thu, Aug 07, 2025 at 06:02:33PM -0500, Corey Minyard wrote:
> > If the driver goes into any maintenance mode, disable sysfs access until
> > it is done.
> >
> 
> Why specifically sysfs reads during FW update state? Is there an expectation
> that during a FW update, that redfish/ipmi/etc... are chunking/buffering the
> FW payloads to the device, thus needs write access? I'm assuming that the
> device is blocking waiting for paylods to finish, so sending additional messages
> just get ignored?

In my experience, when the BMC goes into firmware update mode, it
doesn't behave normally.  But it's just my experience.  It general, it's
best not to mess with something during an update.

-corey

> 
> > If the driver goes into reset maintenance mode, disable all messages
> > until it is done.
> > 
> > Signed-off-by: Corey Minyard <corey@minyard.net>
> > ---
> >  drivers/char/ipmi/ipmi_msghandler.c | 11 +++++++++++
> >  1 file changed, 11 insertions(+)
> > 
> > diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
> > index f124c0b33db8..72f5f4a0c056 100644
> > --- a/drivers/char/ipmi/ipmi_msghandler.c
> > +++ b/drivers/char/ipmi/ipmi_msghandler.c
> > @@ -2338,6 +2338,11 @@ static int i_ipmi_request(struct ipmi_user     *user,
> >  
> >  	if (!run_to_completion)
> >  		mutex_lock(&intf->users_mutex);
> > +	if (intf->maintenance_mode_state == IPMI_MAINTENANCE_MODE_STATE_RESET) {
> > +		/* No messages while the BMC is in reset. */
> > +		rv = -EBUSY;
> > +		goto out_err;
> > +	}
> >  	if (intf->in_shutdown) {
> >  		rv = -ENODEV;
> >  		goto out_err;
> > @@ -2639,6 +2644,12 @@ static int __bmc_get_device_id(struct ipmi_smi *intf, struct bmc_device *bmc,
> >  	    (bmc->dyn_id_set && time_is_after_jiffies(bmc->dyn_id_expiry)))
> >  		goto out_noprocessing;
> >  
> > +	/* Don't allow sysfs access when in maintenance mode. */
> > +	if (intf->maintenance_mode_state) {
> > +		rv = -EBUSY;
> > +		goto out_noprocessing;
> > +	}
> > +
> >  	prev_guid_set = bmc->dyn_guid_set;
> >  	__get_guid(intf);
> >  
> > -- 
> > 2.43.0
> > 
> 
> Best, Fred