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

From: Eryu Guan <eguan@redhat.com>
To: Steve French <smfrench@gmail.com>
Cc: Dave Chinner <david@fromorbit.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: Sat, 15 Nov 2014 13:35:33 +0800	[thread overview]
Message-ID: <20141115053533.GK2863@dhcp-13-216.nay.redhat.com> (raw)
In-Reply-To: <CAH2r5msD-FDDvUL5Gt+7Fzt-tvduS93sxM-PG9dZjvk0ED53QA@mail.gmail.com>

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.

[root@hp-dl388eg8-01 xfstests]# ./check -nfs generic/001
FSTYP         -- nfs
PLATFORM      -- Linux/x86_64 hp-dl388eg8-01 3.18.0-rc4+
MKFS_OPTIONS  -- -bsize=4096 localhost:/mnt/nfsscratch
MOUNT_OPTIONS -- -o context=system_u:object_r:nfs_t:s0 localhost:/mnt/nfsscratch

our local _scratch_mkfs routine ...
mount: can't find localhost:/mnt/nfsscratch in /etc/fstab
rm -rf /*
umount: localhost:/mnt/nfsscratch: mountpoint not found
check: failed to mkfs $SCRATCH_DEV using specified options
Passed all 0 tests

(I replaced the real "rm -rf ..." by "echo 'rm -rf ...' in above test)

> 
> The patch below fixes it for me but it wasn't immediately obvious how to best
> return info to the user (ie print messages that make sense here -
> "echo" seems to be supressed
> in common/rc and notrun exits and logs it to a file but not to the
> screen in this case)
> 
> sfrench@ubuntu:~/xfstests$ git diff -a
> diff --git a/common/rc b/common/rc
> index d5e3aff..866244b 100644
> --- a/common/rc
> +++ b/common/rc
> @@ -555,6 +555,9 @@ _mkfs_dev()
>  _scratch_cleanup_files()
>  {
>         _scratch_mount
> +       if ! [ "$SCRATCH_MNT" ]; then
> +               _notrun "this test requires a \$SCRATCH_MNT to be specified"
> +       fi
>         rm -rf $SCRATCH_MNT/*
>         _scratch_unmount
>  }

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
        _scratch_mount
        rm -rf $SCRATCH_MNT/*
        _scratch_unmount

Thanks,
Eryu
