Re: [PATCH for-11.1?] qemu-iotest 161: fix race

[Kevin Wolf <kwolf@redhat.com>]

Am 28.07.2026 um 18:39 hat Michael Tokarev geschrieben:
> qemu-iotest 161 fails intermittedly due to a race condition:
> 
> qemu:block / io-qcow2-161             ERROR            2.08s   exit status 1
> ――――――――――――――――――――――――――――――――――― ✀  ―――――――――――――――――――――――――――――――――――――
> stderr:
> --- tests/qemu-iotests/161.out
> +++ scratch/qcow2-file-161/161.out.bad
> @@ -34,6 +34,8 @@
>  *** Commit and then change an option on the backing file
> 
>  Formatting 'TEST_DIR/t.IMGFMT.base', fmt=IMGFMT size=1048576
> +qemu-img: TEST_DIR/t.IMGFMT.base: Failed to get "write" lock
> +Is another process using the image [TEST_DIR/t.IMGFMT.base]?
>  Formatting 'TEST_DIR/t.IMGFMT.int', fmt=IMGFMT size=1048576 backing_file=TEST_DIR/t.IMGFMT.base backing_fmt=IMGFMT
>  Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1048576 backing_file=TEST_DIR/t.IMGFMT.int backing_fmt=IMGFMT
>  { 'execute': 'qmp_capabilities' }
> 
> This test is run right after a previous test, where we've
> killed qemu process which holds the test image open.
> It looks like when the next test is started (with creating
> the image files), old qemu is still running, so we're racing
> with that qemu, and qemu-img is unable to lock the image file
> properly.
> 
> We can add some `sleep $little-amount` here, but it is simpler
> and more reliable to just remove the image files, so that new
> ones are created.
> 
> Resolves: https://gitlab.com/qemu-project/qemu/-/work_items/2867
> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
> 
> diff --git a/tests/qemu-iotests/161 b/tests/qemu-iotests/161
> index f25effab936..0b8ba0b19e2 100755
> --- a/tests/qemu-iotests/161
> +++ b/tests/qemu-iotests/161
> @@ -106,6 +106,7 @@ echo
>  echo "*** Commit and then change an option on the backing file"
>  echo
>  # Create the images again
> +rm -f -- "$TEST_IMG.base" "$TEST_IMG.int"
>  TEST_IMG="$TEST_IMG.base" _make_test_img $IMG_SIZE
>  TEST_IMG="$TEST_IMG.int" _make_test_img -b "$TEST_IMG.base" -F $IMGFMT
>  _make_test_img -b "$TEST_IMG.int" -F $IMGFMT

This can only work for the file protocol, but the test also supports
fuse, which is now broken.

Kevin


161   fail       [19:51:58] [19:52:03]   5.3s                 output mismatch (see /home/kwolf/source/qemu/build-clang/scratch/qcow2-fuse-161/161.out.bad)
--- /home/kwolf/source/qemu/tests/qemu-iotests/161.out
+++ /home/kwolf/source/qemu/build-clang/scratch/qcow2-fuse-161/161.out.bad
@@ -33,6 +33,8 @@

 *** Commit and then change an option on the backing file

+rm: cannot remove '/tmp/qemu-iotests-9_5xqdbm/qcow2-fuse-161/fuse-t.qcow2.base': Device or resource busy
+rm: cannot remove '/tmp/qemu-iotests-9_5xqdbm/qcow2-fuse-161/fuse-t.qcow2.int': Device or resource busy
 Formatting 'TEST_DIR/t.IMGFMT.base', fmt=IMGFMT size=1048576
 Formatting 'TEST_DIR/t.IMGFMT.int', fmt=IMGFMT size=1048576 backing_file=TEST_DIR/t.IMGFMT.base backing_fmt=IMGFMT
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1048576 backing_file=TEST_DIR/t.IMGFMT.int backing_fmt=IMGFMT
Failures: 161
Failed 1 of 1 iotests