[PATCH v3] ext4/309: add test for ext4_dir_entry2 wipe

[Leah Rumancik <leah.rumancik@gmail.com>]

From: Leah Rumancik <lrumancik@google.com>

Check wiping of dir entry data upon removing a file, converting to an
htree, and splitting htree nodes.

Tests commit 6c0912739699d8e4b6a87086401bf3ad3c59502d ("ext4: wipe
ext4_dir_entry2 upon file deletion").

Signed-off-by: Leah Rumancik <leah.rumancik@gmail.com>

Changes in v2:
- fix formatting
- use _get_block_size instead of manually finding blocksize
- change scratch_dir to testdir to avoid confusion

Changes in v3:
- add _require_od_endian_flag function
- skip test 309 if od does not support endian flag
---
 common/rc          |   9 +++
 tests/ext4/309     | 192 +++++++++++++++++++++++++++++++++++++++++++++
 tests/ext4/309.out |   5 ++
 tests/ext4/group   |   1 +
 4 files changed, 207 insertions(+)
 create mode 100755 tests/ext4/309
 create mode 100644 tests/ext4/309.out

diff --git a/common/rc b/common/rc
index 2cf550ec..8b8807d5 100644
--- a/common/rc
+++ b/common/rc
@@ -4513,6 +4513,15 @@ _getcap()
 	return ${PIPESTATUS[0]}
 }
 
+#od only supports --endian flag in versions 8.23 and later
+_require_od_endian_flag()
+{
+	version="$(od --version | grep -m 1 -o -E '[0-9.]+')"
+	[[ "${version%%.*}" -lt "8" ]] || \
+		[[ "${version%%.*}" -eq "8" && "${version##*.}" -lt "23" ]] && \
+		_notrun "od does not support endian flag"
+}
+
 init_rc
 
 ################################################################################
diff --git a/tests/ext4/309 b/tests/ext4/309
new file mode 100755
index 00000000..e0497e1a
--- /dev/null
+++ b/tests/ext4/309
@@ -0,0 +1,192 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2021 Google, Inc. All Rights Reserved.
+#
+# FS QA Test No. 309
+#
+# Test wiping of ext4_dir_entry2 data upon file removal, conversion
+# to htree, and splitting of htree nodes
+#
+seq=`basename $0`
+seqres=$RESULT_DIR/$seq
+echo "QA output created by $seq"
+
+status=1       # failure is the default!
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+
+# remove previous $seqres.full before test
+rm -f $seqres.full
+
+# real QA test starts here
+_supported_fs ext4
+
+_require_scratch
+_require_command "$DEBUGFS_PROG" debugfs
+_require_od_endian_flag
+
+testdir="${SCRATCH_MNT}/testdir"
+
+# get block number filename's dir ent
+# argument 1: filename
+get_block() {
+	echo $($DEBUGFS_PROG $SCRATCH_DEV -R "dirsearch /testdir $1" 2>> $seqres.full | grep -o -m 1 "phys [0-9]\+" | cut -c 6-)
+}
+
+# get offset of filename's dirent within the block
+# argument 1: filename
+get_offset() {
+	echo $($DEBUGFS_PROG $SCRATCH_DEV -R "dirsearch /testdir $1" 2>> $seqres.full | grep -o -m 1 "offset [0-9]\+" | cut -c 8-)
+}
+
+# get record length of dir ent at specified block and offset
+# argument 1: block
+# argument 2: offset
+get_reclen() {
+	echo $(od $SCRATCH_DEV --skip-bytes=$(($1 * $blocksize + $2 + 4)) --read-bytes=2  -d -An  --endian=little | tr -d ' \t\n\r')
+}
+
+# reads portion of dirent that should be zero'd out (starting at offset of name_len = 6)
+# and trims 0s and whitespace
+# argument 1: block num containing dir ent
+# argument 2: offset of dir ent within block
+# argument 3: rec len of dir ent
+read_dir_ent() {
+	echo $(od $SCRATCH_DEV --skip-bytes=$(($1 * $blocksize + $2 + 6)) --read-bytes=$(($3 - 6)) -d -An -v | sed -e 's/[0 \t\n\r]//g')
+}
+
+# forces node split on test directory
+# can be used to convert to htree and to split node on existing htree
+# looks for jump in directory size as indicator of node split
+induce_node_split() {
+	_scratch_mount >> $seqres.full 2>&1
+	dir_size="$(stat --printf="%s" $testdir)"
+	while [[ "$(stat --printf="%s" $testdir)" == "$dir_size" ]]; do
+		file_num=$(($file_num + 1))
+		touch $testdir/test"$(printf "%04d" $file_num)"
+	done
+	_scratch_unmount >> $seqres.full 2>&1
+}
+
+#
+# TEST 1: dir entry fields wiped upon file removal
+#
+
+test_file1="test0001"
+test_file2="test0002"
+test_file3="test0003"
+
+_scratch_mkfs_sized $((128 * 1024 * 1024)) >> $seqres.full 2>&1
+
+# create scratch dir for testing
+# create some files with no name a substr of another name so we can grep later
+_scratch_mount >> $seqres.full 2>&1
+blocksize="$(_get_block_size $SCRATCH_MNT)"
+mkdir $testdir
+file_num=1
+for file_num in {1..10}; do
+	touch $testdir/test"$(printf "%04d" $file_num)"
+done
+_scratch_unmount >> $seqres.full 2>&1
+
+# get block, offset, and rec_len of two test files
+block1=$(get_block $test_file1)
+offset1=$(get_offset $test_file1)
+rec_len1=$(get_reclen $block1 $offset1)
+
+block2=$(get_block $test_file2)
+offset2=$(get_offset $test_file2)
+rec_len2=$(get_reclen $block2 $offset2)
+
+_scratch_mount >> $seqres.full 2>&1
+rm $testdir/$test_file1
+_scratch_unmount >> $seqres.full 2>&1
+
+# read name_len field to end of dir entry
+check1=$(read_dir_ent $block1 $offset1 $rec_len1)
+check2=$(read_dir_ent $block2 $offset2 $rec_len2)
+
+# if check is empty, bytes read was all 0's, file data wiped
+# at this point, check1 should be empty, but check 2 should not be
+if [ -z "$check1" ] && [ ! -z "$check2" ]; then
+	echo "Test 1 part 1 passed."
+else
+	_fail "ERROR (test 1 part 1): metadata not wiped upon removing test file 1"
+fi
+
+_scratch_mount >> $seqres.full 2>&1
+rm $testdir/$test_file2
+_scratch_unmount >> $seqres.full 2>&1
+
+check2=$(read_dir_ent $block2 $offset2 $rec_len2)
+
+# at this point, both should be wiped
+[ -z "$check2" ] && echo "Test 1 part 2 passed." || _fail "ERROR (test 1 part 2): metadata not wiped upon removing test file 2"
+
+#
+# TEST 2: old dir entry fields wiped when directory converted to htree
+#
+
+# get original location
+block1=$(get_block $test_file3)
+offset1=$(get_offset $test_file3)
+rec_len1=$(get_reclen $block1 $offset1)
+
+# sanity check, ensures not an htree yet
+check_htree=$($DEBUGFS_PROG $SCRATCH_DEV -R "htree_dump /testdir" 2>&1)
+if [[ "$check_htree" != *"htree_dump: Not a hash-indexed directory"* ]]; then
+	_fail "ERROR (test 2): already an htree"
+fi
+
+# force conversion to htree
+induce_node_split
+
+# ensure it is now an htree
+check_htree=$($DEBUGFS_PROG $SCRATCH_DEV -R "htree_dump /testdir" 2>&1)
+if [[ "$check_htree" == *"htree_dump: Not a hash-indexed directory"* ]]; then
+	_fail "ERROR (test 2): directory was not converted to an htree after creation of many files"
+fi
+
+# check that old data was wiped
+# (this location is not immediately reused by ext4)
+check1=$(read_dir_ent $block1 $offset1 $rec_len1)
+
+# at this point, check1 should be empty meaning data was wiped
+[ -z "$check1" ] &&  echo "Test 2 passed." || _fail "ERROR (test 2): file metadata not wiped during conversion to htree"
+
+#
+# TEST 3: old dir entries wiped when moved to another block during split_node
+#
+
+# force splitting of a node
+induce_node_split
+# use debugfs to get names of two files from block 3
+hdump=$($DEBUGFS_PROG $SCRATCH_DEV -R "htree_dump /testdir" 2>> $seqres.full)
+
+# get line number of "Reading directory block 3"
+block3_line=$(echo "$hdump" | awk '/Reading directory block 3/{ print NR; exit }')
+
+[ -z "$block3_line" ] && echo "ERROR (test 3): could not find block number 3 after node split"
+
+test_file1=$(echo "$hdump" | sed -n "$(($block3_line + 1))"p | cut -d ' ' -f4)
+test_file2=$(echo "$hdump" | sed -n "$(($block3_line + 2))"p | cut -d ' ' -f4)
+
+# check these filenames don't exist in block 1 or 2
+# get block numbers of first two blocks
+block1=$(echo "$hdump" | grep -o -m 1 "Reading directory block 1, phys [0-9]\+" | cut -c 33-)
+block2=$(echo "$hdump" | grep -o -m 1 "Reading directory block 2, phys [0-9]\+" | cut -c 33-)
+
+# search all of both these blocks for these file names
+check1=$(od $SCRATCH_DEV --skip-bytes=$(($block1 * $blocksize)) --read-bytes=$blocksize -c -An -v | tr -d '\\ \t\n\r\v' | grep -e $test_file1 -e $test_file2)
+check2=$(od $SCRATCH_DEV --skip-bytes=$(($block2 * $blocksize)) --read-bytes=$blocksize -c -An -v | tr -d '\\ \t\n\r\v' | grep -e $test_file1 -e $test_file2)
+
+if [ -z "$check1" ] && [ -z "$check2" ]; then
+	echo "Test 3 passed."
+else
+	_fail "ERROR (test 3): file name not wiped during node split"
+fi
+
+status=0
+exit
diff --git a/tests/ext4/309.out b/tests/ext4/309.out
new file mode 100644
index 00000000..e5febaac
--- /dev/null
+++ b/tests/ext4/309.out
@@ -0,0 +1,5 @@
+QA output created by 309
+Test 1 part 1 passed.
+Test 1 part 2 passed.
+Test 2 passed.
+Test 3 passed.
diff --git a/tests/ext4/group b/tests/ext4/group
index ceda2ba6..e7ad3c24 100644
--- a/tests/ext4/group
+++ b/tests/ext4/group
@@ -59,3 +59,4 @@
 306 auto rw resize quick
 307 auto ioctl rw defrag
 308 auto ioctl rw prealloc quick defrag
+309 auto quick dir
-- 
2.32.0.rc1.229.g3e70b5a671-goog