reflink: test what happens when we hit resource limits

Add a few horrible opt-in stress tests to see what happens if we try
to reflink the same block billions of times, and what happens if we
run out of space while reflinking a file.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>

tests/generic/175

@@ -0,0 +1,99 @@
+#! /bin/bash
+# FS QA Test No. 175
+#
+# Try to hit the maximum reference count (eek!)
+#
+# This test runs extremely slowly, so it's not automatically run anywhere.
+#
+#-----------------------------------------------------------------------
+# Copyright (c) 2015, Oracle and/or its affiliates.  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 -rf "$tmp".* "$TESTDIR1"
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+. ./common/attr
+. ./common/reflink
+
+# real QA test starts here
+_supported_os Linux
+_require_scratch_reflink
+_require_cp_reflink
+
+rm -f "$seqres.full"
+
+echo "Format and mount"
+_scratch_mkfs > "$seqres.full" 2>&1
+_scratch_mount >> "$seqres.full" 2>&1
+
+TESTDIR="$SCRATCH_MNT/test-$seq"
+rm -rf "$TESTDIR"
+mkdir "$TESTDIR"
+
+# Well let's hope the maximum reflink count is (less than (ha!)) 2^32...
+
+echo "Create a one block file"
+BLKSZ="$(stat -f "$TESTDIR" -c '%S')"
+_pwrite_byte 0x61 0 $BLKSZ "$TESTDIR/file1" >> "$seqres.full"
+_pwrite_byte 0x62 0 $BLKSZ "$TESTDIR/file2" >> "$seqres.full"
+_cp_reflink "$TESTDIR/file1" "$TESTDIR/file2" >> "$seqres.full"
+
+nr=32
+fnr=32
+for i in $(seq 0 $fnr); do
+	echo " ++ Reflink size $i, $(( (2 ** i) * BLKSZ)) bytes" | tee -a "$seqres.full"
+	n=$(( (2 ** i) * BLKSZ))
+	_reflink_range "$TESTDIR/file1" 0 "$TESTDIR/file1" $n $n >> "$seqres.full" || break
+done
+
+nrf=$((nr - fnr))
+echo "Clone $((2 ** nrf)) files"
+seq 0 $((2 ** nrf)) | while read i; do
+	_cp-reflink "$TESTDIR/file1" "$TESTDIR/file1-$i"
+done
+
+echo "Check scratch fs"
+umount "$SCRATCH_MNT"
+_check_scratch_fs
+
+echo "Remove big file and recheck"
+_scratch_mount >> "$seqres.full" 2>&1
+umount "$SCRATCH_MNT"
+_check_scratch_fs
+
+echo "Remove all files and recheck"
+_scratch_mount >> "$seqres.full" 2>&1
+umount "$SCRATCH_MNT"
+_check_scratch_fs
+
+# success, all done
+status=0
+exit

tests/generic/176

@@ -0,0 +1,81 @@
+#! /bin/bash
+# FS QA Test No. 176
+#
+# Try to run out of space while cloning?
+#
+#-----------------------------------------------------------------------
+# Copyright (c) 2015, Oracle and/or its affiliates.  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 -rf "$tmp".* "$TESTDIR1"
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+. ./common/attr
+. ./common/reflink
+
+# real QA test starts here
+_supported_os Linux
+_require_scratch_reflink
+
+rm -f "$seqres.full"
+
+echo "Format and mount"
+_scratch_mkfs > "$seqres.full" 2>&1
+_scratch_mount >> "$seqres.full" 2>&1
+
+TESTDIR="$SCRATCH_MNT/test-$seq"
+rm -rf "$TESTDIR"
+mkdir "$TESTDIR"
+
+BLKSZ="$(stat -f "$TESTDIR" -c '%S')"
+NR_FREE="$(stat -f -c '%f' "$TESTDIR")"
+echo "Create a big file"
+touch "$TESTDIR/file0" "$TESTDIR/file1"
+_pwrite_byte 0x61 0 $((BLKSZ * NR_FREE)) "$TESTDIR/bigfile" >> "$seqres.full" 2>&1
+_scratch_remount
+sz="$(stat -c '%s' "$TESTDIR/bigfile")"
+
+blks="$((sz / BLKSZ))"
+echo "Try to reflink"
+seq 0 $blks | while read lblk; do
+	fname="$TESTDIR/file$((lblk % 2))"
+	out="$(_reflink_range "$TESTDIR/bigfile" $((lblk * BLKSZ)) "$fname" $((lblk * BLKSZ)) $BLKSZ 2>&1)"
+	echo "$fname: $out" >> "$seqres.full"
+	echo "$out" | grep -q "No space left on device" && break
+done
+
+echo "Check scratch fs"
+umount "$SCRATCH_MNT"
+_check_scratch_fs
+
+# success, all done
+status=0
+exit

tests/generic/176.out

@@ -0,0 +1,5 @@
+QA output created by 176
+Format and mount
+Create a big file
+Try to reflink
+Check scratch fs

tests/generic/group

@@ -177,6 +177,8 @@
 172 auto quick clone
 173 auto quick clone
 174 auto quick clone
+175 clone_stress
+176 clone_stress
 184 metadata auto quick
 192 atime auto
 193 metadata auto quick