From 98a6203999a0270d5e0b8ab3ca9a995527e5def4 Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Mon, 20 Apr 2020 13:34:53 +0300 Subject: [PATCH] overlay: another test for dropping nlink below zero This is a variant on test overlay/034. This variant is mangling upper hardlinks instead of lower hardlinks and does not require the inodes index feature. This is a regression test for kernel commit 83552eacdfc0 ("ovl: fix WARN_ON nlink drop to zero") Signed-off-by: Amir Goldstein Reviewed-by: Eryu Guan Signed-off-by: Eryu Guan --- tests/overlay/072 | 85 +++++++++++++++++++++++++++++++++++++++++++ tests/overlay/072.out | 3 ++ tests/overlay/group | 1 + 3 files changed, 89 insertions(+) create mode 100755 tests/overlay/072 create mode 100644 tests/overlay/072.out diff --git a/tests/overlay/072 b/tests/overlay/072 new file mode 100755 index 00000000..d2cb93b9 --- /dev/null +++ b/tests/overlay/072 @@ -0,0 +1,85 @@ +#! /bin/bash +# SPDX-License-Identifier: GPL-2.0 +# Copyright (C) 2020 CTERA Networks. All Rights Reserved. +# +# FS QA Test 072 +# +# Test overlay nlink when adding upper hardlinks. +# +# nlink of overlay inode could be dropped indefinitely by adding +# unaccounted upper hardlinks underneath a mounted overlay and +# trying to remove them. +# +# This is a variant of test overlay/034 with mangling of upper instead +# of lower hardlinks. Unlike overlay/034, this test does not require the +# inode index feature and will pass whether is it enabled or disabled +# by default. +# +# This is a regression test for kernel commit 83552eacdfc0 +# ("ovl: fix WARN_ON nlink drop to zero"). +# Without the fix, the test triggers +# WARN_ON(inode->i_nlink == 0) in drop_link(). +# +seq=`basename $0` +seqres=$RESULT_DIR/$seq +echo "QA output created by $seq" + +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 + +# remove previous $seqres.full before test +rm -f $seqres.full + +# real QA test starts here +_supported_fs overlay +_supported_os Linux +_require_scratch + +upperdir=$OVL_BASE_SCRATCH_MNT/$OVL_UPPER + +# Remove all files from previous tests +_scratch_mkfs + +# Create upper hardlink +mkdir -p $upperdir +touch $upperdir/0 +ln $upperdir/0 $upperdir/1 + +_scratch_mount + +# Verify overlay inode nlink 2 same as upper inode +stat -c '%h' $SCRATCH_MNT/0 + +# Add upper hardlinks while overlay is mounted - overlay inode nlink +# is not being updated +ln $upperdir/0 $upperdir/2 +ln $upperdir/0 $upperdir/3 + +# Unlink the 2 un-accounted upper hardlinks - overlay inode nlinks +# drops 2 and may reach 0 if the situation is not detected +rm $SCRATCH_MNT/2 +rm $SCRATCH_MNT/3 + +# Check if getting ENOENT when trying to link !I_LINKABLE with nlink 0 +ln $SCRATCH_MNT/0 $SCRATCH_MNT/4 + +# Unlink all hardlinks - if overlay inode nlink is 0, this will trigger +# WARN_ON() in drop_nlink() +rm $SCRATCH_MNT/0 +rm $SCRATCH_MNT/1 +rm $SCRATCH_MNT/4 + +echo "Silence is golden" +status=0 +exit diff --git a/tests/overlay/072.out b/tests/overlay/072.out new file mode 100644 index 00000000..28eeb940 --- /dev/null +++ b/tests/overlay/072.out @@ -0,0 +1,3 @@ +QA output created by 072 +2 +Silence is golden diff --git a/tests/overlay/group b/tests/overlay/group index 43ad8a52..82876d09 100644 --- a/tests/overlay/group +++ b/tests/overlay/group @@ -74,3 +74,4 @@ 069 auto quick copyup hardlink exportfs nested nonsamefs 070 auto quick copyup redirect nested 071 auto quick copyup redirect nested nonsamefs +072 auto quick copyup hardlink -- 2.30.2