Re: [PATCH v2 1/5] common: re-enable tests that require scratch dev on NFS

From: Eryu Guan <eguan@redhat.com>
To: Dave Chinner <david@fromorbit.com>
Cc: Steve French <smfrench@gmail.com>,
	fstests@vger.kernel.org,
	"linux-nfs@vger.kernel.org" <linux-nfs@vger.kernel.org>,
	"linux-cifs@vger.kernel.org" <linux-cifs@vger.kernel.org>,
	Weston Andros Adamson <dros@primarydata.com>
Subject: Re: [PATCH v2 1/5] common: re-enable tests that require scratch dev on NFS
Date: Mon, 17 Nov 2014 14:06:03 +0800	[thread overview]
Message-ID: <20141117060603.GO2863@dhcp-13-216.nay.redhat.com> (raw)
In-Reply-To: <20141117054141.GK23575@dastard>

On Mon, Nov 17, 2014 at 04:41:41PM +1100, Dave Chinner wrote:
> On Sat, Nov 15, 2014 at 01:35:33PM +0800, Eryu Guan wrote:
> > On Fri, Nov 14, 2014 at 11:02:50AM -0600, Steve French wrote:
> > > On Wed, Nov 12, 2014 at 9:33 PM, Dave Chinner <david@fromorbit.com> wrote:
> > > > On Wed, Nov 12, 2014 at 12:36:13PM -0600, Steve French wrote:
> > > >> On Fri, Oct 31, 2014 at 12:03 PM, Eryu Guan <eguan@redhat.com> wrote:
> > > >> > This commit disables tests requires scratch dev running on NFS
> > > >> >
> > > >> > c041421 xfstests: stop special casing nfs and udf
> > > >> >
> > > >> > Now re-enable them to get a larger test coverage on NFS.
> > > >> >
> > > >> > Signed-off-by: Eryu Guan <eguan@redhat.com>
> > > >> > ---
> > > >> >  common/rc | 22 +++++++++++++++++++---
> > > >> >  1 file changed, 19 insertions(+), 3 deletions(-)
> > > >> >
> > > >> > diff --git a/common/rc b/common/rc
> > > >> > index 747cf72..ae03712 100644
> > > >> > --- a/common/rc
> > > >> > +++ b/common/rc
> > > >> > @@ -551,6 +551,14 @@ _mkfs_dev()
> > > >> >      rm -f $tmp_dir.mkfserr $tmp_dir.mkfsstd
> > > >> >  }
> > > >> >
> > > >> > +# remove all files in $SCRATCH_MNT, useful when testing on NFS/CIFS
> > > >> > +_scratch_cleanup_files()
> > > >> > +{
> > > >> > +       _scratch_mount
> > > >> > +       rm -rf $SCRATCH_MNT/*
> > > >> > +       _scratch_unmount
> > > >> > +}
> > > >>
> > > >> There should be a check to make sure SCRATCH_MNT exists before you
> > > >> wipe the whole disk ....
> > > >>
> > > >> so if no SCRATCH_MNT then this does rm -rf/*
> > > >> right ... (and wipes out your whole system ...)
> > > >
> > > > You can't get to that function until after all the checks that
> > > > SCRATCH_MNT exists. i.e. this happens during _scratch_mkfs, and that
> > > > is only called in tests after all the startup checks validate
> > > > devices and mounts exist. i.e. see common/config::get_next_config()
> > > 
> > > Well, I reproduced it easily enough again today (after taking a
> > > snapshot of the VM)
> > > by simply running generic/120 against NFS with SCRATCH_MNT not
> > > specified in local.config
> > > Dros also ran into this problem.
> > 
> > You're right, I missed that _scratch_mkfs is also called by ./check,
> > and if there's no SCRATCH_MNT set in local.config, only SCRATCH_DEV is
> > set, _scratch_mkfs can be dangerous.
> 
> As I asked earlier in this thread: why isn't get_next_config()
> catching this?

I think I see the problem, this patch catches the empty SCRATCH_MNT
and works for me:

eguan@dhcp-13-216:~/workspace/src/xfstests$ git diff

diff --git a/common/config b/common/config
index 1cb08c0..409f1b8 100644
--- a/common/config
+++ b/common/config
@@ -464,7 +464,7 @@ get_next_config() {
                exit 1
        fi
 
-       if [ ! -z "$SCRATCH_MNT" -a ! -d "$SCRATCH_MNT" ]; then
+       if [ ! -z "$SCRATCH_MNT" -o ! -d "$SCRATCH_MNT" ]; then
                echo "common/config: Error: \$SCRATCH_MNT ($SCRATCH_MNT) is not a directory"
                exit 1
        fi

If it looks sane I will send out a patch.

> 
> > I propose this patch, which skips _scratch_cleanup_files if called by check
> > 
> > [root@hp-dl388eg8-01 xfstests]# git diff
> > diff --git a/common/rc b/common/rc
> > index 435f74f..254fb66 100644
> > --- a/common/rc
> > +++ b/common/rc
> > @@ -554,6 +554,11 @@ _mkfs_dev()
> >  # remove all files in $SCRATCH_MNT, useful when testing on NFS/CIFS
> >  _scratch_cleanup_files()
> >  {
> > +       # do nothing if called by check, variables are not fully valided yet
> > +       # SCRATCH_MNT can be empty, which is dangerous
> > +       if [ "$iam" == "check" ]; then
> > +               return
> > +       fi
> 
> Again, this is the wrong place to try to fix this - we haven't fixed
> the landmine that has left us running with an invalid config. IOWs,
> by the time _scratch_mkfs is called from *anywhere* we should have
> fully validated the environment to be correct and valid. Parsing and
> validating the config we have loaded from the config file is the job
> of get_next_config(), yes?

Yes, that makes more sense, thanks for the explanation!

Thanks,
Eryu
> 
> Cheers,
> 
> Dave.
> -- 
> Dave Chinner
> david@fromorbit.com
> --
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