[PATCH 1/2] overlay: dentry leak for default_permissions mount option

[PATCH 1/2] overlay: dentry leak for default_permissions mount option

[Eryu Guan]

overlayfs was leaking dentry on non-directories when using the
'default_permissions' mount option, which resulted in "BUG Dentry
still in use".

The following kernel commit fixed it:
ovl: fix dentry leak for default_permissions

Signed-off-by: Eryu Guan <eguan@redhat.com>
---
 tests/overlay/009     | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++
 tests/overlay/009.out |  2 ++
 tests/overlay/group   |  1 +
 3 files changed, 71 insertions(+)
 create mode 100755 tests/overlay/009
 create mode 100644 tests/overlay/009.out

diff --git a/tests/overlay/009 b/tests/overlay/009
new file mode 100755
index 0000000..de94ca4
--- /dev/null
+++ b/tests/overlay/009
@@ -0,0 +1,68 @@
+#! /bin/bash
+# FS QA Test 009
+#
+# dentry leak for default_permissions mount option
+#
+# This is fixed by kernel commit named as
+# ovl: fix dentry leak for default_permissions
+#
+#-----------------------------------------------------------------------
+# Copyright (c) 2016 Red Hat Inc.  All Rights Reserved.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it would be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write the Free Software Foundation,
+# Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+#-----------------------------------------------------------------------
+#
+
+seq=`basename $0`
+seqres=$RESULT_DIR/$seq
+echo "QA output created by $seq"
+
+here=`pwd`
+tmp=/tmp/$$
+status=1	# failure is the default!
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+_cleanup()
+{
+	cd /
+	rm -f $tmp.*
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+
+rm -f $seqres.full
+
+# real QA test starts here
+_supported_fs overlay
+_supported_os Linux
+_require_scratch
+
+# Remove all files from previous tests
+_scratch_mkfs
+
+# Create test file in lowerdir
+lowerdir=$SCRATCH_DEV/$OVERLAY_LOWER_DIR
+mkdir -p $lowerdir
+touch $lowerdir/testfile
+
+# mount overlay with default_permissions option, get a reference on the dentry
+_scratch_mount -o default_permissions
+cat $SCRATCH_MNT/testfile
+
+# overlay will be unmounted by test harness and kernel BUG if dentry leaked
+echo "Silence is golden"
+status=0
+exit
diff --git a/tests/overlay/009.out b/tests/overlay/009.out
new file mode 100644
index 0000000..7e97715
--- /dev/null
+++ b/tests/overlay/009.out
@@ -0,0 +1,2 @@
+QA output created by 009
+Silence is golden
diff --git a/tests/overlay/group b/tests/overlay/group
index 874bfdd..3f08cd3 100644
--- a/tests/overlay/group
+++ b/tests/overlay/group
@@ -11,3 +11,4 @@
 006 auto quick copyup whiteout
 007 auto quick
 008 auto quick whiteout
+009 auto quick
-- 
2.7.4

[PATCH 2/2] overlay: remove dir which contains whiteout from lower dir

[Eryu Guan]

Test the removal of a dir which contains whiteout from lower dir,
which could crash the kernel.

The following kernel commit fixed this issue
84889d4 ovl: check dentry positiveness in ovl_cleanup_whiteouts()

Signed-off-by: Eryu Guan <eguan@redhat.com>
---
 tests/overlay/010     | 78 +++++++++++++++++++++++++++++++++++++++++++++++++++
 tests/overlay/010.out |  2 ++
 tests/overlay/group   |  1 +
 3 files changed, 81 insertions(+)
 create mode 100755 tests/overlay/010
 create mode 100644 tests/overlay/010.out

diff --git a/tests/overlay/010 b/tests/overlay/010
new file mode 100755
index 0000000..5d1c2bd
--- /dev/null
+++ b/tests/overlay/010
@@ -0,0 +1,78 @@
+#! /bin/bash
+# FS QA Test 010
+#
+# Remove dir which contains whiteout from lower dir.
+#
+# The following kernel commit fixed the kernel crash on the removal
+# 84889d4 ovl: check dentry positiveness in ovl_cleanup_whiteouts()
+#
+#-----------------------------------------------------------------------
+# Copyright (c) 2016 Red Hat Inc.  All Rights Reserved.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it would be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write the Free Software Foundation,
+# Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+#-----------------------------------------------------------------------
+#
+
+seq=`basename $0`
+seqres=$RESULT_DIR/$seq
+echo "QA output created by $seq"
+
+here=`pwd`
+tmp=/tmp/$$
+status=1	# failure is the default!
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+_cleanup()
+{
+	cd /
+	rm -f $tmp.*
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+
+rm -f $seqres.full
+
+# real QA test starts here
+_supported_fs overlay
+_supported_os Linux
+_require_scratch
+
+# Remove all files from previous tests
+_scratch_mkfs
+
+# Need two lower dirs in this test, and we mount overlay ourselves,
+# create upper and workdir as well
+lowerdir1=$SCRATCH_DEV/$OVERLAY_LOWER_DIR.1
+lowerdir2=$SCRATCH_DEV/$OVERLAY_LOWER_DIR.2
+upperdir=$SCRATCH_DEV/$OVERLAY_UPPER_DIR
+workdir=$SCRATCH_DEV/$OVERLAY_WORK_DIR
+mkdir -p $lowerdir1 $lowerdir2 $upperdir $workdir
+
+# One lowerdir contains test dir and test files, the other contains whiteout
+mkdir -p $lowerdir1/testdir $lowerdir2/testdir
+touch $lowerdir1/testdir/a $lowerdir1/testdir/b
+mknod $lowerdir2/testdir/a c 0 0
+
+# Mount overlayfs and remove testdir, which led to kernel crash
+$MOUNT_PROG -t overlay -o lowerdir=$lowerdir2:$lowerdir1 \
+	    -o upperdir=$upperdir,workdir=$workdir \
+	    $SCRATCH_DEV $SCRATCH_MNT
+rm -rf $SCRATCH_MNT/testdir
+
+# success, all done
+echo "Silence is golden"
+status=0
+exit
diff --git a/tests/overlay/010.out b/tests/overlay/010.out
new file mode 100644
index 0000000..1d83a8d
--- /dev/null
+++ b/tests/overlay/010.out
@@ -0,0 +1,2 @@
+QA output created by 010
+Silence is golden
diff --git a/tests/overlay/group b/tests/overlay/group
index 3f08cd3..06cdb7e 100644
--- a/tests/overlay/group
+++ b/tests/overlay/group
@@ -12,3 +12,4 @@
 007 auto quick
 008 auto quick whiteout
 009 auto quick
+010 auto quick whiteout
-- 
2.7.4

Re: [PATCH 2/2] overlay: remove dir which contains whiteout from lower dir

[Xiong Zhou]

On Wed, Jun 29, 2016 at 09:39:34PM +0800, Eryu Guan wrote:
> Test the removal of a dir which contains whiteout from lower dir,
> which could crash the kernel.
> 
> The following kernel commit fixed this issue
> 84889d4 ovl: check dentry positiveness in ovl_cleanup_whiteouts()

Tested and ack these 2 cases.

One minor thought down there.


> 
> Signed-off-by: Eryu Guan <eguan@redhat.com>
> ---
>  tests/overlay/010     | 78 +++++++++++++++++++++++++++++++++++++++++++++++++++
>  tests/overlay/010.out |  2 ++
>  tests/overlay/group   |  1 +
>  3 files changed, 81 insertions(+)
>  create mode 100755 tests/overlay/010
>  create mode 100644 tests/overlay/010.out
> 
> diff --git a/tests/overlay/010 b/tests/overlay/010
> new file mode 100755
> index 0000000..5d1c2bd
> --- /dev/null
> +++ b/tests/overlay/010
> @@ -0,0 +1,78 @@
> +#! /bin/bash
> +# FS QA Test 010
> +#
> +# Remove dir which contains whiteout from lower dir.
> +#
> +# The following kernel commit fixed the kernel crash on the removal
> +# 84889d4 ovl: check dentry positiveness in ovl_cleanup_whiteouts()
> +#
> +#-----------------------------------------------------------------------
> +# Copyright (c) 2016 Red Hat Inc.  All Rights Reserved.
> +#
> +# This program is free software; you can redistribute it and/or
> +# modify it under the terms of the GNU General Public License as
> +# published by the Free Software Foundation.
> +#
> +# This program is distributed in the hope that it would be useful,
> +# but WITHOUT ANY WARRANTY; without even the implied warranty of
> +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> +# GNU General Public License for more details.
> +#
> +# You should have received a copy of the GNU General Public License
> +# along with this program; if not, write the Free Software Foundation,
> +# Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
> +#-----------------------------------------------------------------------
> +#
> +
> +seq=`basename $0`
> +seqres=$RESULT_DIR/$seq
> +echo "QA output created by $seq"
> +
> +here=`pwd`
> +tmp=/tmp/$$
> +status=1	# failure is the default!
> +trap "_cleanup; exit \$status" 0 1 2 3 15
> +
> +_cleanup()
> +{
> +	cd /
> +	rm -f $tmp.*
> +}
> +
> +# get standard environment, filters and checks
> +. ./common/rc
> +. ./common/filter
> +
> +rm -f $seqres.full
> +
> +# real QA test starts here
> +_supported_fs overlay
> +_supported_os Linux
> +_require_scratch
> +
> +# Remove all files from previous tests
> +_scratch_mkfs
> +
> +# Need two lower dirs in this test, and we mount overlay ourselves,
> +# create upper and workdir as well
> +lowerdir1=$SCRATCH_DEV/$OVERLAY_LOWER_DIR.1
> +lowerdir2=$SCRATCH_DEV/$OVERLAY_LOWER_DIR.2
> +upperdir=$SCRATCH_DEV/$OVERLAY_UPPER_DIR
> +workdir=$SCRATCH_DEV/$OVERLAY_WORK_DIR
> +mkdir -p $lowerdir1 $lowerdir2 $upperdir $workdir
> +
> +# One lowerdir contains test dir and test files, the other contains whiteout
> +mkdir -p $lowerdir1/testdir $lowerdir2/testdir
> +touch $lowerdir1/testdir/a $lowerdir1/testdir/b
> +mknod $lowerdir2/testdir/a c 0 0
> +
> +# Mount overlayfs and remove testdir, which led to kernel crash
> +$MOUNT_PROG -t overlay -o lowerdir=$lowerdir2:$lowerdir1 \
> +	    -o upperdir=$upperdir,workdir=$workdir \
> +	    $SCRATCH_DEV $SCRATCH_MNT
> +rm -rf $SCRATCH_MNT/testdir

sleep 1 second here ?  Or we could panic after "Pass all 1 tests"
printed. [untested..]

Thanks,
Xiong
> +
> +# success, all done
> +echo "Silence is golden"
> +status=0
> +exit
> diff --git a/tests/overlay/010.out b/tests/overlay/010.out
> new file mode 100644
> index 0000000..1d83a8d
> --- /dev/null
> +++ b/tests/overlay/010.out
> @@ -0,0 +1,2 @@
> +QA output created by 010
> +Silence is golden
> diff --git a/tests/overlay/group b/tests/overlay/group
> index 3f08cd3..06cdb7e 100644
> --- a/tests/overlay/group
> +++ b/tests/overlay/group
> @@ -12,3 +12,4 @@
>  007 auto quick
>  008 auto quick whiteout
>  009 auto quick
> +010 auto quick whiteout
> -- 
> 2.7.4
> 
> --
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Re: [PATCH 2/2] overlay: remove dir which contains whiteout from lower dir

[Eryu Guan]

On Thu, Jun 30, 2016 at 03:41:01PM +0800, Xiong Zhou wrote:
> On Wed, Jun 29, 2016 at 09:39:34PM +0800, Eryu Guan wrote:
> > Test the removal of a dir which contains whiteout from lower dir,
> > which could crash the kernel.
> > 
> > The following kernel commit fixed this issue
> > 84889d4 ovl: check dentry positiveness in ovl_cleanup_whiteouts()
> 
> Tested and ack these 2 cases.
> 
> One minor thought down there.

Thanks!

> 
> 
> > 
> > Signed-off-by: Eryu Guan <eguan@redhat.com>
> > ---
> >  tests/overlay/010     | 78 +++++++++++++++++++++++++++++++++++++++++++++++++++
> >  tests/overlay/010.out |  2 ++
> >  tests/overlay/group   |  1 +
> >  3 files changed, 81 insertions(+)
> >  create mode 100755 tests/overlay/010
> >  create mode 100644 tests/overlay/010.out
> > 
> > diff --git a/tests/overlay/010 b/tests/overlay/010
> > new file mode 100755
> > index 0000000..5d1c2bd
> > --- /dev/null
> > +++ b/tests/overlay/010
> > @@ -0,0 +1,78 @@
> > +#! /bin/bash
> > +# FS QA Test 010
> > +#
> > +# Remove dir which contains whiteout from lower dir.
> > +#
> > +# The following kernel commit fixed the kernel crash on the removal
> > +# 84889d4 ovl: check dentry positiveness in ovl_cleanup_whiteouts()
> > +#
> > +#-----------------------------------------------------------------------
> > +# Copyright (c) 2016 Red Hat Inc.  All Rights Reserved.
> > +#
> > +# This program is free software; you can redistribute it and/or
> > +# modify it under the terms of the GNU General Public License as
> > +# published by the Free Software Foundation.
> > +#
> > +# This program is distributed in the hope that it would be useful,
> > +# but WITHOUT ANY WARRANTY; without even the implied warranty of
> > +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> > +# GNU General Public License for more details.
> > +#
> > +# You should have received a copy of the GNU General Public License
> > +# along with this program; if not, write the Free Software Foundation,
> > +# Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
> > +#-----------------------------------------------------------------------
> > +#
> > +
> > +seq=`basename $0`
> > +seqres=$RESULT_DIR/$seq
> > +echo "QA output created by $seq"
> > +
> > +here=`pwd`
> > +tmp=/tmp/$$
> > +status=1	# failure is the default!
> > +trap "_cleanup; exit \$status" 0 1 2 3 15
> > +
> > +_cleanup()
> > +{
> > +	cd /
> > +	rm -f $tmp.*
> > +}
> > +
> > +# get standard environment, filters and checks
> > +. ./common/rc
> > +. ./common/filter
> > +
> > +rm -f $seqres.full
> > +
> > +# real QA test starts here
> > +_supported_fs overlay
> > +_supported_os Linux
> > +_require_scratch
> > +
> > +# Remove all files from previous tests
> > +_scratch_mkfs
> > +
> > +# Need two lower dirs in this test, and we mount overlay ourselves,
> > +# create upper and workdir as well
> > +lowerdir1=$SCRATCH_DEV/$OVERLAY_LOWER_DIR.1
> > +lowerdir2=$SCRATCH_DEV/$OVERLAY_LOWER_DIR.2
> > +upperdir=$SCRATCH_DEV/$OVERLAY_UPPER_DIR
> > +workdir=$SCRATCH_DEV/$OVERLAY_WORK_DIR
> > +mkdir -p $lowerdir1 $lowerdir2 $upperdir $workdir
> > +
> > +# One lowerdir contains test dir and test files, the other contains whiteout
> > +mkdir -p $lowerdir1/testdir $lowerdir2/testdir
> > +touch $lowerdir1/testdir/a $lowerdir1/testdir/b
> > +mknod $lowerdir2/testdir/a c 0 0
> > +
> > +# Mount overlayfs and remove testdir, which led to kernel crash
> > +$MOUNT_PROG -t overlay -o lowerdir=$lowerdir2:$lowerdir1 \
> > +	    -o upperdir=$upperdir,workdir=$workdir \
> > +	    $SCRATCH_DEV $SCRATCH_MNT
> > +rm -rf $SCRATCH_MNT/testdir
> 
> sleep 1 second here ?  Or we could panic after "Pass all 1 tests"
> printed. [untested..]

I think this is fine. Latest upstream kernel has this bug fixed, we
don't want to waste extra second waiting for it to "fail". And if it
crashed the kernel, we have to looked at it anyway and would find it is
this test triggered the crash easily.

Thanks,
Eryu