1 files changed, 295 insertions, 0 deletions
diff --git a/tests/qemu-iotests/112 b/tests/qemu-iotests/112
new file mode 100755
index 000000000..07ac74fb2
--- /dev/null
+++ b/tests/qemu-iotests/112
@@ -0,0 +1,295 @@
+#!/usr/bin/env bash
+# group: rw
+#
+# Test cases for different refcount_bits values
+#
+# Copyright (C) 2015 Red Hat, Inc.
+#
+# 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; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will 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, see <http://www.gnu.org/licenses/>.
+#
+
+# creator
+owner=mreitz@redhat.com
+
+seq="$(basename $0)"
+echo "QA output created by $seq"
+
+status=1	# failure is the default!
+
+_cleanup()
+{
+	_cleanup_test_img
+}
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+# get standard environment, filters and checks
+. ./common.rc
+. ./common.filter
+
+# This tests qcow2-specific low-level functionality
+_supported_fmt qcow2
+_supported_proto file fuse
+# This test will set refcount_bits on its own which would conflict with the
+# manual setting; compat will be overridden as well;
+# and external data files do not work well with our refcount testing
+_unsupported_imgopts refcount_bits 'compat=0.10' data_file
+
+print_refcount_bits()
+{
+    $QEMU_IMG info "$TEST_IMG" | sed -n '/refcount bits:/ s/^ *//p'
+}
+
+echo
+echo '=== refcount_bits limits ==='
+echo
+
+# Must be positive (non-zero)
+_make_test_img -o "refcount_bits=0" 64M
+# Must be positive (non-negative)
+_make_test_img -o "refcount_bits=-1" 64M
+# May not exceed 64
+_make_test_img -o "refcount_bits=128" 64M
+# Must be a power of two
+_make_test_img -o "refcount_bits=42" 64M
+
+# 1 is the minimum
+_make_test_img -o "refcount_bits=1" 64M
+print_refcount_bits
+
+# 64 is the maximum
+_make_test_img -o "refcount_bits=64" 64M
+print_refcount_bits
+
+# 16 is the default
+_make_test_img 64M
+print_refcount_bits
+
+echo
+echo '=== refcount_bits and compat=0.10 ==='
+echo
+
+# Should work
+_make_test_img -o "compat=0.10,refcount_bits=16" 64M
+print_refcount_bits
+
+# Should not work
+_make_test_img -o "compat=0.10,refcount_bits=1" 64M
+_make_test_img -o "compat=0.10,refcount_bits=64" 64M
+
+
+echo
+echo '=== Snapshot limit on refcount_bits=1 ==='
+echo
+
+_make_test_img -o "refcount_bits=1" 64M
+print_refcount_bits
+
+$QEMU_IO -c 'write 0 512' "$TEST_IMG" | _filter_qemu_io
+
+# Should fail for now; in the future, this might be supported by automatically
+# copying all clusters with overflowing refcount
+$QEMU_IMG snapshot -c foo "$TEST_IMG"
+
+# The new L1 table could/should be leaked
+_check_test_img
+
+echo
+echo '=== Snapshot limit on refcount_bits=2 ==='
+echo
+
+_make_test_img -o "refcount_bits=2" 64M
+print_refcount_bits
+
+$QEMU_IO -c 'write 0 512' "$TEST_IMG" | _filter_qemu_io
+
+# Should succeed
+$QEMU_IMG snapshot -c foo "$TEST_IMG"
+$QEMU_IMG snapshot -c bar "$TEST_IMG"
+# Should fail (4th reference)
+$QEMU_IMG snapshot -c baz "$TEST_IMG"
+
+# The new L1 table could/should be leaked
+_check_test_img
+
+echo
+echo '=== Compressed clusters with refcount_bits=1 ==='
+echo
+
+_make_test_img -o "refcount_bits=1" 64M
+print_refcount_bits
+
+# Both should fit into a single host cluster; instead of failing to increase the
+# refcount of that cluster, qemu should just allocate a new cluster and make
+# this operation succeed
+$QEMU_IO -c 'write -P 0 -c  0  64k' \
+         -c 'write -P 1 -c 64k 64k' \
+         "$TEST_IMG" | _filter_qemu_io
+
+_check_test_img
+
+echo
+echo '=== MSb set in 64 bit refcount ==='
+echo
+
+_make_test_img -o "refcount_bits=64" 64M
+print_refcount_bits
+
+$QEMU_IO -c 'write 0 512' "$TEST_IMG" | _filter_qemu_io
+
+# Set the MSb in the refblock entry of the data cluster
+poke_file "$TEST_IMG" $((0x20028)) "\x80\x00\x00\x00\x00\x00\x00\x00"
+
+# Clear OFLAG_COPIED in the L2 entry of the data cluster
+poke_file "$TEST_IMG" $((0x40000)) "\x00\x00\x00\x00\x00\x05\x00\x00"
+
+# Try to write to that cluster (should work, even though the MSb is set)
+$QEMU_IO -c 'write 0 512' "$TEST_IMG" | _filter_qemu_io
+
+echo
+echo '=== Snapshot on maximum 64 bit refcount value ==='
+echo
+
+_make_test_img -o "refcount_bits=64" 64M
+print_refcount_bits
+
+$QEMU_IO -c 'write 0 512' "$TEST_IMG" | _filter_qemu_io
+
+# Set the refblock entry to the maximum value possible
+poke_file "$TEST_IMG" $((0x20028)) "\xff\xff\xff\xff\xff\xff\xff\xff"
+
+# Clear OFLAG_COPIED in the L2 entry of the data cluster
+poke_file "$TEST_IMG" $((0x40000)) "\x00\x00\x00\x00\x00\x05\x00\x00"
+
+# Try a snapshot (should correctly identify the overflow; may work in the future
+# by falling back to COW)
+$QEMU_IMG snapshot -c foo "$TEST_IMG"
+
+# The new L1 table could/should be leaked; and obviously the data cluster is
+# leaked (refcount=UINT64_MAX reference=1)
+_check_test_img
+
+echo
+echo '=== Amend from refcount_bits=16 to refcount_bits=1 ==='
+echo
+
+_make_test_img 64M
+print_refcount_bits
+
+$QEMU_IO -c 'write 16M 32M' "$TEST_IMG" | _filter_qemu_io
+$QEMU_IMG amend -o refcount_bits=1 "$TEST_IMG"
+_check_test_img
+print_refcount_bits
+
+echo
+echo '=== Amend from refcount_bits=1 to refcount_bits=64 ==='
+echo
+
+$QEMU_IMG amend -o refcount_bits=64 "$TEST_IMG"
+_check_test_img
+print_refcount_bits
+
+echo
+echo '=== Amend to compat=0.10 ==='
+echo
+
+# Should not work because refcount_bits needs to be 16 for compat=0.10
+$QEMU_IMG amend -o compat=0.10 "$TEST_IMG"
+print_refcount_bits
+# Should work
+$QEMU_IMG amend -o compat=0.10,refcount_bits=16 "$TEST_IMG"
+_check_test_img
+print_refcount_bits
+
+# Get back to compat=1.1 and refcount_bits=16
+$QEMU_IMG amend -o compat=1.1 "$TEST_IMG"
+print_refcount_bits
+# Should not work
+$QEMU_IMG amend -o refcount_bits=32,compat=0.10 "$TEST_IMG"
+print_refcount_bits
+
+echo
+echo '=== Amend with snapshot ==='
+echo
+
+$QEMU_IMG snapshot -c foo "$TEST_IMG"
+# Just to have different refcounts across the image
+$QEMU_IO -c 'write 0 16M' "$TEST_IMG" | _filter_qemu_io
+
+# Should not work (may work in the future by first decreasing all refcounts so
+# they fit into the target range by copying them)
+$QEMU_IMG amend -o refcount_bits=1 "$TEST_IMG"
+_check_test_img
+print_refcount_bits
+
+# Should work
+$QEMU_IMG amend -o refcount_bits=2 "$TEST_IMG"
+_check_test_img
+print_refcount_bits
+
+echo
+echo '=== Testing too many references for check ==='
+echo
+
+_make_test_img -o "refcount_bits=1" 64M
+print_refcount_bits
+
+# This cluster should be created at 0x50000
+$QEMU_IO -c 'write 0 64k' "$TEST_IMG" | _filter_qemu_io
+# Now make the second L2 entry (the L2 table should be at 0x40000) point to that
+# cluster, so we have two references
+poke_file "$TEST_IMG" $((0x40008)) "\x80\x00\x00\x00\x00\x05\x00\x00"
+
+# This should say "please use amend"
+_check_test_img -r all
+
+# So we do that
+$QEMU_IMG amend -o refcount_bits=2 "$TEST_IMG"
+print_refcount_bits
+
+# And try again
+_check_test_img -r all
+
+echo
+echo '=== Multiple walks necessary during amend ==='
+echo
+
+_make_test_img -o "refcount_bits=1,cluster_size=512" 64k
+
+# Cluster 0 is the image header, clusters 1 to 4 are used by the L1 table, a
+# single L2 table, the reftable and a single refblock. This creates 58 data
+# clusters (actually, the L2 table is created here, too), so in total there are
+# then 63 used clusters in the image. With a refcount width of 64, one refblock
+# describes 64 clusters (512 bytes / 64 bits/entry = 64 entries), so this will
+# make the first refblock in the amended image have exactly one free entry.
+$QEMU_IO -c "write 0 $((58 * 512))" "$TEST_IMG" | _filter_qemu_io
+
+# Now change the refcount width; since the first new refblock will have exactly
+# one free entry, that entry will be used to store its own reference. No other
+# refblocks are needed, so then the new reftable will be allocated; since the
+# first new refblock is completely filled up, this will require a new refblock
+# which is why the refcount width changing function will need to run through
+# everything one more time until the allocations are stable.
+# Having more walks than usual should be visible as regressing progress (from
+# 66.67 % (2/3 walks) to 50.00 % (2/4 walks)).
+$QEMU_IMG amend -o refcount_bits=64 -p "$TEST_IMG" | tr '\r' '\n' \
+                                                   | grep -A 1 '66.67'
+print_refcount_bits
+
+_check_test_img
+
+
+# success, all done
+echo '*** done'
+rm -f $seq.full
+status=0