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iotests: Filter 175's allocation information

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It is possible for an empty file to take up blocks on a filesystem, for
example:

$ qemu-img create -f raw test.img 1G
Formatting 'test.img', fmt=raw size=1073741824
$ mkfs.ext4 -I 128 -q test.img
$ mkdir test-mount
$ sudo mount -o loop test.img test-mount
$ sudo touch test-mount/test-file
$ stat -c 'blocks=%b' test-mount/test-file
blocks=8

These extra blocks (one cluster) are apparently used for metadata,
because they are always there, on top of blocks used for data:

$ sudo dd if=/dev/zero of=test-mount/test-file bs=1M count=1
1+0 records in
1+0 records out
1048576 bytes (1.0 MB, 1.0 MiB) copied, 0.00135339 s, 775 MB/s
$ stat -c 'blocks=%b' test-mount/test-file
blocks=2056

Make iotest 175 take this into account.

Reported-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Nir Soffer <nsoffer@redhat.com>
Message-id: 20190516144319.12570-1-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
This commit is contained in:
Max Reitz 2019-05-16 16:43:19 +02:00
parent 9e8dfad045
commit a3bd71b577
2 changed files with 26 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
tests/qemu-iotests/175
View File

@ -28,10 +28,25 @@ status=1 # failure is the default!
_cleanup()
{
_cleanup_test_img
_cleanup_test_img
rm -f "$TEST_DIR/empty"
}
trap "_cleanup; exit \$status" 0 1 2 3 15
# Some file systems sometimes allocate extra blocks independently of
# the file size. This function hides the resulting difference in the
# stat -c '%b' output.
# Parameter 1: Number of blocks an empty file occupies
# Parameter 2: Image size in bytes
_filter_blocks()
{
extra_blocks=$1
img_size=$2
sed -e "s/blocks=$extra_blocks\\(\$\\|[^0-9]\\)/nothing allocated/" \
-e "s/blocks=$((extra_blocks + img_size / 512))\\(\$\\|[^0-9]\\)/everything allocated/"
}
# get standard environment, filters and checks
. ./common.rc
. ./common.filter
@ -40,18 +55,21 @@ _supported_fmt raw
_supported_proto file
_supported_os Linux
size=1m
size=$((1 * 1024 * 1024))
touch "$TEST_DIR/empty"
extra_blocks=$(stat -c '%b' "$TEST_DIR/empty")
echo
echo "== creating image with default preallocation =="
_make_test_img $size | _filter_imgfmt
stat -c "size=%s, blocks=%b" $TEST_IMG
stat -c "size=%s, blocks=%b" $TEST_IMG | _filter_blocks $extra_blocks $size
for mode in off full falloc; do
echo
echo "== creating image with preallocation $mode =="
IMGOPTS=preallocation=$mode _make_test_img $size | _filter_imgfmt
stat -c "size=%s, blocks=%b" $TEST_IMG
stat -c "size=%s, blocks=%b" $TEST_IMG | _filter_blocks $extra_blocks $size
done
# success, all done

8
tests/qemu-iotests/175.out
View File

@ -2,17 +2,17 @@ QA output created by 175
== creating image with default preallocation ==
Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1048576
size=1048576, blocks=0
size=1048576, nothing allocated
== creating image with preallocation off ==
Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1048576 preallocation=off
size=1048576, blocks=0
size=1048576, nothing allocated
== creating image with preallocation full ==
Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1048576 preallocation=full
size=1048576, blocks=2048
size=1048576, everything allocated
== creating image with preallocation falloc ==
Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1048576 preallocation=falloc
size=1048576, blocks=2048
size=1048576, everything allocated
*** done