Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
MIME-Version: 1.0
References: <CAFVqi1R0Cc4+wqwCr9-8HoTU+6cShzorD44YzDNyex+jv1dztA@mail.gmail.com>
 <20200328195932.GA96482@google.com>
In-Reply-To: <20200328195932.GA96482@google.com>
From:   Kelsey <skunberg.kelsey@gmail.com>
Date:   Sun, 29 Mar 2020 01:20:42 -0600
Message-ID: <CAFVqi1Td3kE0Gd6S43F5xs3br=UBd1ssZu-1xkoO+Z9EYRQR=w@mail.gmail.com>
Subject: Re: [Linux-kernel-mentees] [PATCH v2] PCI: sysfs: Change bus_rescan
 and dev_rescan to rescan
To:     Bjorn Helgaas <helgaas@kernel.org>
Cc:     Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        linux-pci@vger.kernel.org,
        Kelsey Skunberg <kelsey.skunberg@gmail.com>,
        rbilovol@cisco.com, stable <stable@vger.kernel.org>,
        Don Dutile <ddutile@redhat.com>,
        Ruslan Bilovol <ruslan.bilovol@gmail.com>,
        linux-kernel-mentees@lists.linuxfoundation.org,
        Bodong Wang <bodong@mellanox.com>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Sat, Mar 28, 2020 at 1:59 PM Bjorn Helgaas <helgaas@kernel.org> 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@kernel.org> 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