[PATCH 3/6] xfs/117: fix fragility in this fuzz test

["Darrick J. Wong" <djwong@kernel.org>]

From: Darrick J. Wong <djwong@kernel.org>

This fuzz test has some fragility problems -- it doesn't do anything to
guarantee that the inodes that it checks for EFSCORRUPTED are the same
ones that it fuzzed, and it doesn't explicitly try to avoid victimizing
inodes in the same chunk as the root directory.  As a result, this test
fails annoyingly frequently.

Fix both of these problems and get rid of the confusingly named TESTDIR
variable.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---
 tests/xfs/117 |   47 +++++++++++++++++++++++++++++------------------
 1 file changed, 29 insertions(+), 18 deletions(-)


diff --git a/tests/xfs/117 b/tests/xfs/117
index d3f4675f..32be525f 100755
--- a/tests/xfs/117
+++ b/tests/xfs/117
@@ -39,8 +39,7 @@ _require_xfs_db_blocktrash_z_command
 test -z "${FUZZ_ARGS}" && FUZZ_ARGS="-n 8 -3"
 
 rm -f $seqres.full
-TESTDIR="${SCRATCH_MNT}/scratchdir"
-TESTFILE="${TESTDIR}/testfile"
+victimdir="${SCRATCH_MNT}/scratchdir"
 
 echo "+ create scratch fs"
 _scratch_mkfs_xfs > /dev/null
@@ -50,37 +49,49 @@ _scratch_mount
 blksz="$(stat -f -c '%s' "${SCRATCH_MNT}")"
 
 echo "+ make some files"
-mkdir -p "${TESTDIR}"
-for x in `seq 1 1024`; do
-	touch "${SCRATCH_MNT}/junk.${x}"
-	inode="$(stat -c '%i' "${SCRATCH_MNT}/junk.${x}")"
-	if [ "$x" -gt 512 ] && [ "$((inode % 64))" -eq 0 ]; then
-		mv "${SCRATCH_MNT}/junk.${x}" "${TESTFILE}.1"
-		break
-	fi
+mkdir -p "$victimdir"
+
+rootdir="$(stat -c '%i' "$SCRATCH_MNT")"
+rootchunk=$(( rootdir / 64 ))
+
+# First we create some dummy file so that the victim files don't get created
+# in the same inode chunk as the root directory, because a corrupt inode in
+# the root chunk causes mount to fail.
+for ((i = 0; i < 256; i++)); do
+	fname="$SCRATCH_MNT/dummy.$i"
+	touch "$fname"
+	ino="$(stat -c '%i' "$fname")"
+	ichunk=$(( ino / 64 ))
+	test "$ichunk" -gt "$rootchunk" && break
 done
-for x in `seq 2 64`; do
-	touch "${TESTFILE}.${x}"
+
+# Now create some victim files
+inos=()
+for ((i = 0; i < 64; i++)); do
+	fname="$victimdir/test.$i"
+	touch "$fname"
+	inos+=("$(stat -c '%i' "$fname")")
 done
-inode="$(stat -c '%i' "${TESTFILE}.1")"
+echo "First victim inode is: " >> $seqres.full
+stat -c '%i' "$fname" >> $seqres.full
 umount "${SCRATCH_MNT}"
 
 echo "+ check fs"
 _scratch_xfs_repair -n >> $seqres.full 2>&1 || _fail "xfs_repair should not fail"
 
 echo "+ corrupt image"
-seq "${inode}" "$((inode + 63))" | while read ino; do
+for ino in "${inos[@]}"; do
 	_scratch_xfs_db -x -c "inode ${ino}" -c "stack" -c "blocktrash -x 32 -y $((blksz * 8)) -z ${FUZZ_ARGS}" >> $seqres.full 2>&1
 done
 
 echo "+ mount image && modify files"
 broken=1
 if _try_scratch_mount >> $seqres.full 2>&1; then
-
-	for x in `seq 1 64`; do
-		stat "${TESTFILE}.${x}" >> $seqres.full 2>&1
+	for ((i = 0; i < 64; i++)); do
+		fname="$victimdir/test.$i"
+		stat "$fname" &>> $seqres.full
 		test $? -eq 0 && broken=0
-		touch "${TESTFILE}.${x}" >> $seqres.full 2>&1
+		touch "$fname" &>> $seqres.full
 		test $? -eq 0 && broken=0
 	done
 	umount "${SCRATCH_MNT}"