On Thu, 2023-03-30 at 12:12 -0500, Mike Christie wrote:
> On 3/30/23 11:49 AM, Tomas Henzl wrote:
> > Set the state to deleted in sd_shutdown so that the attached LLD
> > doesn't receive new I/O (can happen when in kexec) later after
> > LLD's shutdown function has been called.
> >
> > Signed-off-by: Tomas Henzl <thenzl@xxxxxxxxxx>
> > ---
> > drivers/scsi/sd.c | 7 +++++++
> > 1 file changed, 7 insertions(+)
> >
> > diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
> > index 4f28dd617eca..8095f0302e66 100644
> > --- a/drivers/scsi/sd.c
> > +++ b/drivers/scsi/sd.c
> > @@ -3694,10 +3694,13 @@ static int sd_start_stop_device(struct
> > scsi_disk *sdkp, int start)
> > static void sd_shutdown(struct device *dev)
> > {
> > struct scsi_disk *sdkp = dev_get_drvdata(dev);
> > + struct scsi_device *sdp;
> >
> > if (!sdkp)
> > return; /* this can happen */
> >
> > + sdp = sdkp->device;
> > +
> > if (pm_runtime_suspended(dev))
> > return;
> >
> > @@ -3710,6 +3713,10 @@ static void sd_shutdown(struct device *dev)
> > sd_printk(KERN_NOTICE, sdkp, "Stopping disk\n");
> > sd_start_stop_device(sdkp, 0);
> > }
> > +
> > + mutex_lock(&sdp->state_mutex);
> > + scsi_device_set_state(sdp, SDEV_DEL);
> > + mutex_unlock(&sdp->state_mutex);
> > }
>
> If this is run for device removal what state will be in here?
>
> Are we going to do:
> 1. __scsi_remove_device sets the state to SDEV_CANCEL at the
> beginning of the function
It will also interfere with target and host device removal. They
traverse their own lists and assume that anything in DEL is already
being removed, which won't be the case here. So basically, after this
happens it's impossible to clean the device trees. It also means any
I/O to the root device wouldn't be allowed.
I assume the contention is that if we get here, we're either going for
immediate shutdown or all the root device remounting to read only has
already been done? If so, could you say that?
James
