Re: [Qemu-devel] [Qemu-block] Failing QEMU iotest 175

[Nir Soffer]

On Sat, May 4, 2019 at 12:32 AM Nir Soffer <address@hidden> wrote:

>
>
> On Fri, May 3, 2019, 23:21 Eric Blake <address@hidden> wrote:
>
>> ...
>> >>>  == creating image with preallocation off ==
>> >>>  Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1048576
>> preallocation=off
>> >>> -size=1048576, blocks=0
>> >>> +size=1048576, blocks=2
>> >>>
>> >>>  == creating image with preallocation full ==
>> >>>  Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1048576
>> preallocation=full
>> >>> -size=1048576, blocks=2048
>> >>> +size=1048576, blocks=2050
>> >>
>> >> 2048/2050, so we DO have some indication of whether the file is sparse
>> >> or fully allocated.
>> >
>> > Maybe we could check that the value after "blocks=" is a single digit in
>> > the first case, and matches "blocks=20.." in the second case?
>>
>> I wonder if 'qemu-img map --output=json $TEST_IMG' might be any more
>> reliable (at least for ignoring any extra block allocations associated
>> with the file, if it is some journaling option or xattr or other reason
>> why your files seem to occupy more disk sectors than just the size of
>> the file would imply).
>>
>
> I think it should work better and is more correct, testing actual
> sparsness instead of underlying file system implementation.
>
> I can send a fix next week.
>

I tested this change:

$ git diff
diff --git a/tests/qemu-iotests/175 b/tests/qemu-iotests/175
index d0ffc495c2..0e3faa50e4 100755
--- a/tests/qemu-iotests/175
+++ b/tests/qemu-iotests/175
@@ -43,17 +43,17 @@ _supported_os Linux
 size=1m

 echo
 echo "== creating image with default preallocation =="
 _make_test_img $size | _filter_imgfmt
-stat -c "size=%s, blocks=%b" $TEST_IMG
+$QEMU_IMG map -f $IMGFMT --output json "$TEST_IMG"

 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
+    $QEMU_IMG map -f $IMGFMT --output json "$TEST_IMG"
 done

 # success, all done
 echo "*** done"
 rm -f $seq.full

It almost works:
$ ./check -raw 175
QEMU          --
"/home/nsoffer/src/qemu/build/tests/qemu-iotests/../../x86_64-softmmu/qemu-system-x86_64"
-nodefaults -machine accel=qtest
QEMU_IMG      --
"/home/nsoffer/src/qemu/build/tests/qemu-iotests/../../qemu-img"
QEMU_IO       --
"/home/nsoffer/src/qemu/build/tests/qemu-iotests/../../qemu-io"  --cache
writeback -f raw
QEMU_NBD      --
"/home/nsoffer/src/qemu/build/tests/qemu-iotests/../../qemu-nbd"
IMGFMT        -- raw
IMGPROTO      -- file
PLATFORM      -- Linux/x86_64 lean 5.0.11-100.fc28.x86_64
TEST_DIR      -- /home/nsoffer/src/qemu/build/tests/qemu-iotests/scratch
SOCKET_SCM_HELPER --
/home/nsoffer/src/qemu/build/tests/qemu-iotests/socket_scm_helper

175         - output mismatch (see 175.out.bad)
--- /home/nsoffer/src/qemu/tests/qemu-iotests/175.out 2019-03-23
18:35:17.788177871 +0200
+++ /home/nsoffer/src/qemu/build/tests/qemu-iotests/175.out.bad 2019-05-11
00:06:09.515873624 +0300
@@ -2,17 +2,17 @@

 == creating image with default preallocation ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1048576
-size=1048576, blocks=0
+[{ "start": 0, "length": 1048576, "depth": 0, "zero": true, "data": false,
"offset": 0}]

 == creating image with preallocation off ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1048576 preallocation=off
-size=1048576, blocks=0
+[{ "start": 0, "length": 1048576, "depth": 0, "zero": true, "data": false,
"offset": 0}]

 == creating image with preallocation full ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1048576 preallocation=full
-size=1048576, blocks=2048
+[{ "start": 0, "length": 1048576, "depth": 0, "zero": false, "data": true,
"offset": 0}]

 == creating image with preallocation falloc ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1048576
preallocation=falloc
-size=1048576, blocks=2048
+[{ "start": 0, "length": 1048576, "depth": 0, "zero": true, "data": false,
"offset": 0}]
The "falloc" test looks exactly like "off", qemu-img map does not report
the allocation
status.
Nir