tests/qemu-iotests/125 - qemu - Git at Google

 #!/usr/bin/env bash
 #
 # Test preallocated growth of qcow2 images
 #
 # Copyright (C) 2017 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_image_size_on_host()
 {
     echo $(($(stat -c '%b * %B' "$TEST_IMG_FILE")))
 }

 # get standard environment and filters
 . ./common.rc
 . ./common.filter

 _supported_fmt qcow2
 _supported_proto file
 # Growing a file with a backing file (without preallocation=full or
 # =falloc) requires zeroing the newly added area, which is impossible
 # to do quickly for v2 images, and hence is unsupported.
 _unsupported_imgopts 'compat=0.10'

 if [ -z "$TEST_IMG_FILE" ]; then
     TEST_IMG_FILE=$TEST_IMG
 fi

 # Test whether we are running on a broken XFS version.  There is this
 # bug:

 # $ rm -f foo
 # $ touch foo
 # $ block_size=4096 # Your FS's block size
 # $ fallocate -o $((block_size / 2)) -l $block_size foo
 # $ LANG=C xfs_bmap foo | grep hole
 #         1: [8..15]: hole
 #
 # The problem is that the XFS driver rounds down the offset and
 # rounds up the length to the block size, but independently.  As
 # such, it only allocates the first block in the example above,
 # even though it should allocate the first two blocks (because our
 # request is to fallocate something that touches both the first
 # two blocks).
 #
 # This means that when you then write to the beginning of the
 # second block, the disk usage of the first two blocks grows.
 #
 # That is precisely what fallocate() promises, though: That when you
 # write to an area that you have fallocated, no new blocks will have
 # to be allocated.

 touch "$TEST_IMG_FILE"
 # Assuming there is no FS with a block size greater than 64k
 fallocate -o 65535 -l 2 "$TEST_IMG_FILE"
 len0=$(get_image_size_on_host)

 # Write to something that in theory we have just fallocated
 # (Thus, the on-disk size should not increase)
 poke_file "$TEST_IMG_FILE" 65536 42
 len1=$(get_image_size_on_host)

 if [ $len1 -gt $len0 ]; then
     _notrun "the test filesystem's fallocate() is broken"
 fi

 rm -f "$TEST_IMG_FILE"

 # Generally, we create some image with or without existing preallocation and
 # then resize it. Then we write some data into the image and verify that its
 # size does not change if we have used preallocation.

 # With a cluster size of 512 B, one L2 table covers 64 * 512 B = 32 kB.
 # One cluster of the L1 table covers 64 * 32 kB = 2 MB.
 # There are multiple cases we want to test:
 # (1) Grow an image without having to allocate a new L2 table.
 # (2) Grow an image, having to allocate a new L2 table.
 # (3) Grow an image, having to grow the L1 table.
 # Therefore, we create an image that is 48 kB below 2 MB. Then:
 # (1) We resize it to 2 MB - 32 kB. (+ 16 kB)
 # (2) We resize it to 2 MB.         (+ 48 kB)
 # (3) We resize it to 2 MB + 32 kB. (+ 80 kB)

 # in B
 CREATION_SIZE=$((2 * 1024 * 1024 - 48 * 1024))

 # 512 is the actual test -- but it's good to test 64k as well, just to be sure.
 for cluster_size in 512 64k; do
 # in kB
 for GROWTH_SIZE in 16 48 80; do
     for create_mode in off metadata falloc full; do
         for growth_mode in off metadata falloc full; do
             echo "--- cluster_size=$cluster_size growth_size=$GROWTH_SIZE create_mode=$create_mode growth_mode=$growth_mode ---"

             _make_test_img -o "preallocation=$create_mode,cluster_size=$cluster_size" ${CREATION_SIZE}
             $QEMU_IMG resize -f "$IMGFMT" --preallocation=$growth_mode "$TEST_IMG" +${GROWTH_SIZE}K

             host_size_0=$(get_image_size_on_host)
             file_length_0=$(stat -c '%s' "$TEST_IMG_FILE")

             $QEMU_IO -c "write 0 $CREATION_SIZE" "$TEST_IMG" | _filter_qemu_io

             host_size_1=$(get_image_size_on_host)
             file_length_1=$(stat -c '%s' "$TEST_IMG_FILE")

             $QEMU_IO -c "write $CREATION_SIZE ${GROWTH_SIZE}K" "$TEST_IMG" | _filter_qemu_io

             host_size_2=$(get_image_size_on_host)
             file_length_2=$(stat -c '%s' "$TEST_IMG_FILE")

             # Test creation preallocation: Compare #0 against #1
             if [ $create_mode != off ]; then
                 # The image length should not have grown
                 if [ $file_length_1 -gt $file_length_0 ]; then
                     echo "ERROR (create): Image length has grown from $file_length_0 to $file_length_1"
                 fi
                 if [ $create_mode != metadata ]; then
                     # The host size should not have grown either
                     if [ $host_size_1 -gt $host_size_0 ]; then
                         echo "ERROR (create): Host size has grown from $host_size_0 to $host_size_1"
                     fi
                 fi
             fi

             # Test resize preallocation: Compare #2 against #1
             if [ $growth_mode != off ]; then
                 # The image length should not have grown
                 if [ $file_length_2 -gt $file_length_1 ]; then
                     echo "ERROR (grow): Image length has grown from $file_length_1 to $file_length_2"
                 fi
                 if [ $growth_mode != metadata ]; then
                     # The host size should not have grown either
                     if [ $host_size_2 -gt $host_size_1 ]; then
                         echo "ERROR (grow): Host size has grown from $host_size_1 to $host_size_2"
                     fi
                 fi
             fi

             echo
         done
     done
 done
 done

 # Test image resizing using preallocation and unaligned offsets
 $QEMU_IMG create -f raw "$TEST_IMG.base" 128k | _filter_img_create
 $QEMU_IO -c 'write -q -P 1 0 128k' -f raw "$TEST_IMG.base"
 for orig_size in 31k 33k; do
     for dst_size in 96k 128k; do
         for prealloc in metadata full; do
             echo "--- Resizing image from $orig_size to $dst_size (preallocation=$prealloc) ---"
             _make_test_img -F raw -b "$TEST_IMG.base" -o cluster_size=64k "$orig_size"
             $QEMU_IMG resize -f "$IMGFMT" --preallocation="$prealloc" "$TEST_IMG" "$dst_size"
             # The first part of the image should contain data from the backing file
             $QEMU_IO -c "read -q -P 1 0 ${orig_size}" "$TEST_IMG"
             # The resized part of the image should contain zeroes
             $QEMU_IO -c "read -q -P 0 ${orig_size} 63k" "$TEST_IMG"
             # If the image does not have an external data file we can also verify its
             # actual size. The resized image should have 7 clusters:
             # header, L1 table, L2 table, refcount table, refcount block, 2 data clusters
             if ! _get_data_file "$TEST_IMG" > /dev/null; then
                 expected_file_length=$((65536 * 7))
                 file_length=$(stat -c '%s' "$TEST_IMG_FILE")
                 if [ "$file_length" != "$expected_file_length" ]; then
                     echo "ERROR: file length $file_length (expected $expected_file_length)"
                 fi
             fi
             echo
         done
     done
 done

 # success, all done
 echo '*** done'
 rm -f $seq.full
 status=0
	#!/usr/bin/env bash
	#
	# Test preallocated growth of qcow2 images
	#
	# Copyright (C) 2017 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_image_size_on_host()
	{
	echo $(($(stat -c '%b * %B' "$TEST_IMG_FILE")))
	}

	# get standard environment and filters
	. ./common.rc
	. ./common.filter

	_supported_fmt qcow2
	_supported_proto file
	# Growing a file with a backing file (without preallocation=full or
	# =falloc) requires zeroing the newly added area, which is impossible
	# to do quickly for v2 images, and hence is unsupported.
	_unsupported_imgopts 'compat=0.10'

	if [ -z "$TEST_IMG_FILE" ]; then
	TEST_IMG_FILE=$TEST_IMG
	fi

	# Test whether we are running on a broken XFS version. There is this
	# bug:

	# $ rm -f foo
	# $ touch foo
	# $ block_size=4096 # Your FS's block size
	# $ fallocate -o $((block_size / 2)) -l $block_size foo
	# $ LANG=C xfs_bmap foo \| grep hole
	# 1: [8..15]: hole
	#
	# The problem is that the XFS driver rounds down the offset and
	# rounds up the length to the block size, but independently. As
	# such, it only allocates the first block in the example above,
	# even though it should allocate the first two blocks (because our
	# request is to fallocate something that touches both the first
	# two blocks).
	#
	# This means that when you then write to the beginning of the
	# second block, the disk usage of the first two blocks grows.
	#
	# That is precisely what fallocate() promises, though: That when you
	# write to an area that you have fallocated, no new blocks will have
	# to be allocated.

	touch "$TEST_IMG_FILE"
	# Assuming there is no FS with a block size greater than 64k
	fallocate -o 65535 -l 2 "$TEST_IMG_FILE"
	len0=$(get_image_size_on_host)

	# Write to something that in theory we have just fallocated
	# (Thus, the on-disk size should not increase)
	poke_file "$TEST_IMG_FILE" 65536 42
	len1=$(get_image_size_on_host)

	if [ $len1 -gt $len0 ]; then
	_notrun "the test filesystem's fallocate() is broken"
	fi

	rm -f "$TEST_IMG_FILE"

	# Generally, we create some image with or without existing preallocation and
	# then resize it. Then we write some data into the image and verify that its
	# size does not change if we have used preallocation.

	# With a cluster size of 512 B, one L2 table covers 64 * 512 B = 32 kB.
	# One cluster of the L1 table covers 64 * 32 kB = 2 MB.
	# There are multiple cases we want to test:
	# (1) Grow an image without having to allocate a new L2 table.
	# (2) Grow an image, having to allocate a new L2 table.
	# (3) Grow an image, having to grow the L1 table.
	# Therefore, we create an image that is 48 kB below 2 MB. Then:
	# (1) We resize it to 2 MB - 32 kB. (+ 16 kB)
	# (2) We resize it to 2 MB. (+ 48 kB)
	# (3) We resize it to 2 MB + 32 kB. (+ 80 kB)

	# in B
	CREATION_SIZE=$((2 * 1024 * 1024 - 48 * 1024))

	# 512 is the actual test -- but it's good to test 64k as well, just to be sure.
	for cluster_size in 512 64k; do
	# in kB
	for GROWTH_SIZE in 16 48 80; do
	for create_mode in off metadata falloc full; do
	for growth_mode in off metadata falloc full; do
	echo "--- cluster_size=$cluster_size growth_size=$GROWTH_SIZE create_mode=$create_mode growth_mode=$growth_mode ---"

	_make_test_img -o "preallocation=$create_mode,cluster_size=$cluster_size" ${CREATION_SIZE}
	$QEMU_IMG resize -f "$IMGFMT" --preallocation=$growth_mode "$TEST_IMG" +${GROWTH_SIZE}K

	host_size_0=$(get_image_size_on_host)
	file_length_0=$(stat -c '%s' "$TEST_IMG_FILE")

	$QEMU_IO -c "write 0 $CREATION_SIZE" "$TEST_IMG" \| _filter_qemu_io

	host_size_1=$(get_image_size_on_host)
	file_length_1=$(stat -c '%s' "$TEST_IMG_FILE")

	$QEMU_IO -c "write $CREATION_SIZE ${GROWTH_SIZE}K" "$TEST_IMG" \| _filter_qemu_io

	host_size_2=$(get_image_size_on_host)
	file_length_2=$(stat -c '%s' "$TEST_IMG_FILE")

	# Test creation preallocation: Compare #0 against #1
	if [ $create_mode != off ]; then
	# The image length should not have grown
	if [ $file_length_1 -gt $file_length_0 ]; then
	echo "ERROR (create): Image length has grown from $file_length_0 to $file_length_1"
	fi
	if [ $create_mode != metadata ]; then
	# The host size should not have grown either
	if [ $host_size_1 -gt $host_size_0 ]; then
	echo "ERROR (create): Host size has grown from $host_size_0 to $host_size_1"
	fi
	fi
	fi

	# Test resize preallocation: Compare #2 against #1
	if [ $growth_mode != off ]; then
	# The image length should not have grown
	if [ $file_length_2 -gt $file_length_1 ]; then
	echo "ERROR (grow): Image length has grown from $file_length_1 to $file_length_2"
	fi
	if [ $growth_mode != metadata ]; then
	# The host size should not have grown either
	if [ $host_size_2 -gt $host_size_1 ]; then
	echo "ERROR (grow): Host size has grown from $host_size_1 to $host_size_2"
	fi
	fi
	fi

	echo
	done
	done
	done
	done

	# Test image resizing using preallocation and unaligned offsets
	$QEMU_IMG create -f raw "$TEST_IMG.base" 128k \| _filter_img_create
	$QEMU_IO -c 'write -q -P 1 0 128k' -f raw "$TEST_IMG.base"
	for orig_size in 31k 33k; do
	for dst_size in 96k 128k; do
	for prealloc in metadata full; do
	echo "--- Resizing image from $orig_size to $dst_size (preallocation=$prealloc) ---"
	_make_test_img -F raw -b "$TEST_IMG.base" -o cluster_size=64k "$orig_size"
	$QEMU_IMG resize -f "$IMGFMT" --preallocation="$prealloc" "$TEST_IMG" "$dst_size"
	# The first part of the image should contain data from the backing file
	$QEMU_IO -c "read -q -P 1 0 ${orig_size}" "$TEST_IMG"
	# The resized part of the image should contain zeroes
	$QEMU_IO -c "read -q -P 0 ${orig_size} 63k" "$TEST_IMG"
	# If the image does not have an external data file we can also verify its
	# actual size. The resized image should have 7 clusters:
	# header, L1 table, L2 table, refcount table, refcount block, 2 data clusters
	if ! _get_data_file "$TEST_IMG" > /dev/null; then
	expected_file_length=$((65536 * 7))
	file_length=$(stat -c '%s' "$TEST_IMG_FILE")
	if [ "$file_length" != "$expected_file_length" ]; then
	echo "ERROR: file length $file_length (expected $expected_file_length)"
	fi
	fi
	echo
	done
	done
	done

	# success, all done
	echo '*** done'
	rm -f $seq.full
	status=0