iotests: Test qemu-img convert of zeroed data cluster

This demonstrates what happens when the block status changes in
sub-min_sparse granularity, but all of the parts are zeroed out. The
alignment logic in is_allocated_sectors() prevents that the target image
remains fully sparse as expected, but turns it into a data cluster of
explicit zeros.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20211217164654.1184218-2-vsementsov@virtuozzo.com>
Tested-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

tests/qemu-iotests/122

@@ -251,6 +251,7 @@ $QEMU_IO -c "write -P 0 0 64k" "$TEST_IMG" 2>&1 | _filter_qemu_io | _filter_test
 $QEMU_IO -c "write 0 1k" "$TEST_IMG" 2>&1 | _filter_qemu_io | _filter_testdir
 $QEMU_IO -c "write 8k 1k" "$TEST_IMG" 2>&1 | _filter_qemu_io | _filter_testdir
 $QEMU_IO -c "write 17k 1k" "$TEST_IMG" 2>&1 | _filter_qemu_io | _filter_testdir
+$QEMU_IO -c "write -P 0 65k 1k" "$TEST_IMG" 2>&1 | _filter_qemu_io | _filter_testdir
 
 for min_sparse in 4k 8k; do
     echo

tests/qemu-iotests/122.out

@@ -192,6 +192,8 @@ wrote 1024/1024 bytes at offset 8192
 1 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 wrote 1024/1024 bytes at offset 17408
 1 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 1024/1024 bytes at offset 66560
+1 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 
 convert -S 4k
 [{ "start": 0, "length": 4096, "depth": 0, "present": true, "zero": false, "data": true, "offset": OFFSET},
@@ -199,7 +201,9 @@ convert -S 4k
 { "start": 8192, "length": 4096, "depth": 0, "present": true, "zero": false, "data": true, "offset": OFFSET},
 { "start": 12288, "length": 4096, "depth": 0, "present": false, "zero": true, "data": false},
 { "start": 16384, "length": 4096, "depth": 0, "present": true, "zero": false, "data": true, "offset": OFFSET},
-{ "start": 20480, "length": 67088384, "depth": 0, "present": false, "zero": true, "data": false}]
+{ "start": 20480, "length": 46080, "depth": 0, "present": false, "zero": true, "data": false},
+{ "start": 66560, "length": 1024, "depth": 0, "present": true, "zero": false, "data": true, "offset": OFFSET},
+{ "start": 67584, "length": 67041280, "depth": 0, "present": false, "zero": true, "data": false}]
 
 convert -c -S 4k
 [{ "start": 0, "length": 1024, "depth": 0, "present": true, "zero": false, "data": true},
@@ -211,7 +215,9 @@ convert -c -S 4k
 
 convert -S 8k
 [{ "start": 0, "length": 24576, "depth": 0, "present": true, "zero": false, "data": true, "offset": OFFSET},
-{ "start": 24576, "length": 67084288, "depth": 0, "present": false, "zero": true, "data": false}]
+{ "start": 24576, "length": 41984, "depth": 0, "present": false, "zero": true, "data": false},
+{ "start": 66560, "length": 1024, "depth": 0, "present": true, "zero": false, "data": true, "offset": OFFSET},
+{ "start": 67584, "length": 67041280, "depth": 0, "present": false, "zero": true, "data": false}]
 
 convert -c -S 8k
 [{ "start": 0, "length": 1024, "depth": 0, "present": true, "zero": false, "data": true},