Re: [Linux-kernel-mentees] [PATCH v2] PCI: sysfs: Change bus_rescan and dev_rescan to rescan

From: Kelsey
Date: Sun Mar 29 2020 - 03:21:46 EST


On Sat, Mar 28, 2020 at 1:59 PM Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote:
>
> On Thu, Mar 26, 2020 at 12:29:11AM -0600, Kelsey wrote:
> > On Wed, Mar 25, 2020 at 4:10 PM Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote:
>
> > > Thanks for taking care of this! Two questions:
> > >
> > > 1) You supplied permissions of 0220, but DEVICE_ATTR_WO()
> > > uses__ATTR_WO(), which uses 0200. Shouldn't we keep 0200?
> > >
> >
> > Good catch. Before changing to DEVICE_ATTR_WO(), the permissions used
> > was (S_IWUSR | S_IWGRP), which would be 0220. This means the
> > permissions were mistakenly changed from 0220 to 0200 in the same
> > patch:
> >
> > commit 4e2b79436e4f ("PCI: sysfs: Change DEVICE_ATTR() to DEVICE_ATTR_WO()")
> >
> > To verify DEVICE_ATTR_WO() is using __ATTR_WO() can be seen in
> > /include/linux/device.h
> > To verify permissions for __ATTR_WO() is 0200 can be seen in
> > /inlcude/linux/sysfs.h
> >
> > These attributes had permissions 0220 when first being introduced and
> > before the above mentioned patch, so I'm on the side to believe that
> > 0220 should be used.
>
> I'm not sure it was a mistake that 4e2b79436e4f changed from 0220 to
> 200 or not. I'd say __ATTR_WO (0200) is the "standard" one, and we
> should have a special reason to use 0220.

Sounds good. I didn't find any information or reason stating the
permissions needed to be 0220. So sounds like 0200 will be the winner.

Appreciate the help and you checking this over!

- Kelsey