iotests/221: Discard image before qemu-img map

See the new comment for why this should be done.

I do not have a reproducer on master, but when using FUSE block exports,
this test breaks depending on the underlying filesystem (for me, it
works on tmpfs, but fails on xfs, because the block allocated by
file-posix has 16 kB there instead of 4 kB).

Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20201207152245.66987-1-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

diff --git a/tests/qemu-iotests/221 b/tests/qemu-iotests/221
index ca62b3baa178df7eb4dce479de0a6803a1a7669c..7e6086b205d0407ee63da6bce54c5b2ffd5421f7 100755 (executable)
--- a/tests/qemu-iotests/221
+++ b/tests/qemu-iotests/221
@@ -46,6 +46,13 @@ echo "=== Check mapping of unaligned raw image ==="
 echo
 
 _make_test_img 65537 # qemu-img create rounds size up
+
+# file-posix allocates the first block of any images when it is created;
+# the size of this block depends on the host page size and the file
+# system block size, none of which are constant.  Discard the whole
+# image so we will not see this allocation in qemu-img map's output.
+$QEMU_IO -c 'discard 0 65537' "$TEST_IMG" | _filter_qemu_io
+
 $QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
 
 truncate --size=65537 "$TEST_IMG" # so we resize it and check again

diff --git a/tests/qemu-iotests/221.out b/tests/qemu-iotests/221.out
index dca024a0c3dbda67a75e46c72c75acb5d2088d57..93846c7dabb6d62508e650207ecfbd1643322eeb 100644 (file)
--- a/tests/qemu-iotests/221.out
+++ b/tests/qemu-iotests/221.out
@@ -3,18 +3,16 @@ QA output created by 221
 === Check mapping of unaligned raw image ===
 
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=65537
-[{ "start": 0, "length": 4096, "depth": 0, "zero": false, "data": true, "offset": OFFSET},
-{ "start": 4096, "length": 61952, "depth": 0, "zero": true, "data": false, "offset": OFFSET}]
-[{ "start": 0, "length": 4096, "depth": 0, "zero": false, "data": true, "offset": OFFSET},
-{ "start": 4096, "length": 61952, "depth": 0, "zero": true, "data": false, "offset": OFFSET}]
+discard 65537/65537 bytes at offset 0
+64.001 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+[{ "start": 0, "length": 66048, "depth": 0, "zero": true, "data": false, "offset": OFFSET}]
+[{ "start": 0, "length": 66048, "depth": 0, "zero": true, "data": false, "offset": OFFSET}]
 wrote 1/1 bytes at offset 65536
 1 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-[{ "start": 0, "length": 4096, "depth": 0, "zero": false, "data": true, "offset": OFFSET},
-{ "start": 4096, "length": 61440, "depth": 0, "zero": true, "data": false, "offset": OFFSET},
+[{ "start": 0, "length": 65536, "depth": 0, "zero": true, "data": false, "offset": OFFSET},
 { "start": 65536, "length": 1, "depth": 0, "zero": false, "data": true, "offset": OFFSET},
 { "start": 65537, "length": 511, "depth": 0, "zero": true, "data": false, "offset": OFFSET}]
-[{ "start": 0, "length": 4096, "depth": 0, "zero": false, "data": true, "offset": OFFSET},
-{ "start": 4096, "length": 61440, "depth": 0, "zero": true, "data": false, "offset": OFFSET},
+[{ "start": 0, "length": 65536, "depth": 0, "zero": true, "data": false, "offset": OFFSET},
 { "start": 65536, "length": 1, "depth": 0, "zero": false, "data": true, "offset": OFFSET},
 { "start": 65537, "length": 511, "depth": 0, "zero": true, "data": false, "offset": OFFSET}]
 *** done