[PATCH] generic/375: clarify flipping the write bit

[PATCH] generic/375: clarify flipping the write bit

[Matthew Broomfield]

When checking if SGID is cleared upon chmod / setfacl the write bit is
flipped just to make sure permission changes are happening. This is
orthogonal to testing SGID.

Added this information to the test description.

Signed-off-by: Matthew Broomfield <mattysweeps@google.com>
---
 tests/generic/375 | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tests/generic/375 b/tests/generic/375
index eb675144..44670350 100755
--- a/tests/generic/375
+++ b/tests/generic/375
@@ -7,6 +7,9 @@
 # Check if SGID is cleared upon chmod / setfacl when the owner is not in the
 # owning group.
 #
+# The test flips the write bit to easily observe that chmod / setfacl are
+# successful. This is unrelated to testing SGID.
+#
 . ./common/preamble
 _begin_fstest auto quick acl perms
 
-- 
2.46.0.rc2.264.g509ed76dc8-goog

Re: [PATCH] generic/375: clarify flipping the write bit

[Matthew Broomfield]

On Thu, Aug 1, 2024 at 4:04 PM Matthew Broomfield
<mattysweeps@google.com> wrote:
>
> When checking if SGID is cleared upon chmod / setfacl the write bit is
> flipped just to make sure permission changes are happening. This is
> orthogonal to testing SGID.
>
> Added this information to the test description.
>
> Signed-off-by: Matthew Broomfield <mattysweeps@google.com>
> ---
>  tests/generic/375 | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/tests/generic/375 b/tests/generic/375
> index eb675144..44670350 100755
> --- a/tests/generic/375
> +++ b/tests/generic/375
> @@ -7,6 +7,9 @@
>  # Check if SGID is cleared upon chmod / setfacl when the owner is not in the
>  # owning group.
>  #
> +# The test flips the write bit to easily observe that chmod / setfacl are
> +# successful. This is unrelated to testing SGID.
> +#
>  . ./common/preamble
>  _begin_fstest auto quick acl perms
>
> --
> 2.46.0.rc2.264.g509ed76dc8-goog
>

Hello, can someone review if the comment in this patch is accurate?
Thanks in advance for your time.

Re: [PATCH] generic/375: clarify flipping the write bit

[Darrick J. Wong]

On Sat, Sep 14, 2024 at 01:18:03PM -0700, Matthew Broomfield wrote:
> On Thu, Aug 1, 2024 at 4:04 PM Matthew Broomfield
> <mattysweeps@google.com> wrote:
> >
> > When checking if SGID is cleared upon chmod / setfacl the write bit is
> > flipped just to make sure permission changes are happening. This is
> > orthogonal to testing SGID.
> >
> > Added this information to the test description.
> >
> > Signed-off-by: Matthew Broomfield <mattysweeps@google.com>
> > ---
> >  tests/generic/375 | 3 +++
> >  1 file changed, 3 insertions(+)
> >
> > diff --git a/tests/generic/375 b/tests/generic/375
> > index eb675144..44670350 100755
> > --- a/tests/generic/375
> > +++ b/tests/generic/375
> > @@ -7,6 +7,9 @@
> >  # Check if SGID is cleared upon chmod / setfacl when the owner is not in the
> >  # owning group.
> >  #
> > +# The test flips the write bit to easily observe that chmod / setfacl are
> > +# successful. This is unrelated to testing SGID.
> > +#
> >  . ./common/preamble
> >  _begin_fstest auto quick acl perms
> >
> > --
> > 2.46.0.rc2.264.g509ed76dc8-goog
> >
> 
> Hello, can someone review if the comment in this patch is accurate?
> Thanks in advance for your time.

I don't understand this new comment -- "flipping the write bit" is what
the chmod does, and that's what clears setgid.

--D