Re: [PATCH] generic/556: Adequate expected output to touch behavior change

["Darrick J. Wong" <djwong@kernel.org>]

On Wed, May 18, 2022 at 02:32:28PM -0700, Eric Biggers wrote:
> On Wed, May 18, 2022 at 04:22:14PM -0400, Gabriel Krisman Bertazi wrote:
> > Coreutils commit d435cfc0bc55 ("touch: fix wrong
> > diagnostic (Bug#48106)"), released in coreutils v9.0, changed the error
> > reported by the tool when openat() fails with EINVAL.  Instead of
> > reporting a generic message for the failure of either openat() or the
> > following utimensat(), it now differentiates both failures with
> > different messages.
> > 
> > This change breaks generic/556, which relied on the parsing of that
> > message.  This test was originally developed by me on a Debian
> > Buster (coreutils v8.x), so I used the generic error message.  Now that
> > I tried to run it on a more modern distro, it reports a different error
> > message, which fails the test.
> > 
> > We could do it in a more flexible way to catch future changes.  These
> > are unlikely, and many other parts of fstests just use this generic
> > touch message, so don't bother with it here.
> > 
> > There is no change in behavior on the kernel side, just a broken test.
> > On both older and new distros, the kernel correctly rejects this invalid
> > sequence with -EINVAL, as shown in the strace hunk below:
> > 
> > ...
> > openat(AT_FDCWD, "/scratch_mnt/strict/corac\314\247\303", ...) = -1 EINVAL
> > utimensat(AT_FDCWD, "/scratch_mnt/strict/corac\314\247\303", ...) = -1 EINVAL
> > ...
> > 
> > Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
> > ---
> >  tests/generic/556.out | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> > 
> > diff --git a/tests/generic/556.out b/tests/generic/556.out
> > index f9dd9542fb12..12c77a5b0176 100644
> > --- a/tests/generic/556.out
> > +++ b/tests/generic/556.out
> > @@ -12,5 +12,5 @@ user.foo="bar"
> >  # file: SCRATCH_MNT/xattrs/x/f1
> >  user.foo="bar"
> >  
> > -touch: setting times of 'SCRATCH_MNT/strict/corac'$'\314\247\303': Invalid argument
> > -touch: setting times of 'SCRATCH_MNT/strict/cora'$'\303\247\303': Invalid argument
> > +touch: cannot touch 'SCRATCH_MNT/strict/corac'$'\314\247\303': Invalid argument
> > +touch: cannot touch 'SCRATCH_MNT/strict/cora'$'\303\247\303': Invalid argument
> 
> This would break the test on systems that still have an older version of
> coreutils, right?  For example, currently kvm-xfstests test appliances are based
> on Debian Bullseye by default, which isn't very old, but it has coreutils 8.32.
> 
> Can you filter the output to allow the test to pass with both old and new
> coreutils versions?  Or, find another way to test the same thing without relying
> on a tool that has changed its output.

Seconded, those of us running ancient distros like Ubuntu 22.04 will
need compatibility with 8.32 for a few years yet... ;)

--D

> - Eric