tests/qemu-iotests/112 - qemu - Git at Google

 #!/bin/bash
 #
 # 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"

 here="$PWD"
 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
 _supported_os Linux
 # This test will set refcount_bits on its own which would conflict with the
 # manual setting; compat will be overridden as well
 _unsupported_imgopts refcount_bits 'compat=0.10'

 function 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)
 IMGOPTS="$IMGOPTS,refcount_bits=0" _make_test_img 64M
 # Must be positive (non-negative)
 IMGOPTS="$IMGOPTS,refcount_bits=-1" _make_test_img 64M
 # May not exceed 64
 IMGOPTS="$IMGOPTS,refcount_bits=128" _make_test_img 64M
 # Must be a power of two
 IMGOPTS="$IMGOPTS,refcount_bits=42" _make_test_img 64M

 # 1 is the minimum
 IMGOPTS="$IMGOPTS,refcount_bits=1" _make_test_img 64M
 print_refcount_bits

 # 64 is the maximum
 IMGOPTS="$IMGOPTS,refcount_bits=64" _make_test_img 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
 IMGOPTS="$IMGOPTS,compat=0.10,refcount_bits=16" _make_test_img 64M
 print_refcount_bits

 # Should not work
 IMGOPTS="$IMGOPTS,compat=0.10,refcount_bits=1" _make_test_img 64M
 IMGOPTS="$IMGOPTS,compat=0.10,refcount_bits=64" _make_test_img 64M


 echo
 echo '=== Snapshot limit on refcount_bits=1 ==='
 echo

 IMGOPTS="$IMGOPTS,refcount_bits=1" _make_test_img 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

 IMGOPTS="$IMGOPTS,refcount_bits=2" _make_test_img 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

 IMGOPTS="$IMGOPTS,refcount_bits=1" _make_test_img 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

 IMGOPTS="$IMGOPTS,refcount_bits=64" _make_test_img 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

 IMGOPTS="$IMGOPTS,refcount_bits=64" _make_test_img 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

 IMGOPTS="$IMGOPTS,refcount_bits=1" _make_test_img 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

 IMGOPTS="$IMGOPTS,refcount_bits=1,cluster_size=512" _make_test_img 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
	#!/bin/bash
	#
	# 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"

	here="$PWD"
	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
	_supported_os Linux
	# This test will set refcount_bits on its own which would conflict with the
	# manual setting; compat will be overridden as well
	_unsupported_imgopts refcount_bits 'compat=0.10'

	function 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)
	IMGOPTS="$IMGOPTS,refcount_bits=0" _make_test_img 64M
	# Must be positive (non-negative)
	IMGOPTS="$IMGOPTS,refcount_bits=-1" _make_test_img 64M
	# May not exceed 64
	IMGOPTS="$IMGOPTS,refcount_bits=128" _make_test_img 64M
	# Must be a power of two
	IMGOPTS="$IMGOPTS,refcount_bits=42" _make_test_img 64M

	# 1 is the minimum
	IMGOPTS="$IMGOPTS,refcount_bits=1" _make_test_img 64M
	print_refcount_bits

	# 64 is the maximum
	IMGOPTS="$IMGOPTS,refcount_bits=64" _make_test_img 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
	IMGOPTS="$IMGOPTS,compat=0.10,refcount_bits=16" _make_test_img 64M
	print_refcount_bits

	# Should not work
	IMGOPTS="$IMGOPTS,compat=0.10,refcount_bits=1" _make_test_img 64M
	IMGOPTS="$IMGOPTS,compat=0.10,refcount_bits=64" _make_test_img 64M


	echo
	echo '=== Snapshot limit on refcount_bits=1 ==='
	echo

	IMGOPTS="$IMGOPTS,refcount_bits=1" _make_test_img 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

	IMGOPTS="$IMGOPTS,refcount_bits=2" _make_test_img 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

	IMGOPTS="$IMGOPTS,refcount_bits=1" _make_test_img 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

	IMGOPTS="$IMGOPTS,refcount_bits=64" _make_test_img 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

	IMGOPTS="$IMGOPTS,refcount_bits=64" _make_test_img 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

	IMGOPTS="$IMGOPTS,refcount_bits=1" _make_test_img 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

	IMGOPTS="$IMGOPTS,refcount_bits=1,cluster_size=512" _make_test_img 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