Re: [PATCH 1/3] iotests/290: add test case to check 'discard-no-unref' option behavior

[Kevin Wolf <kwolf@redhat.com>]

Am 27.10.2026 um 11:44 hat Andrey Drobyshev geschrieben:
> We basically fill 2 images with identical data and perform discard
> operations with and without 'discard-no-unref' enabled.  Then we check
> that images still read identically, that their disk usage is the same
> (i.e. fallocate(FALLOC_FL_PUNCH_HOLE|FALLOC_FL_KEEP_SIZE) is called for
> both) and that with the option enabled cluster is still marked as
> allocated in "qemu-img map" output.  We also check that the option
> doesn't work with qcow2 v2 images.
> 
> Signed-off-by: Andrey Drobyshev <andrey.drobyshev@virtuozzo.com>
> Reviewed-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
> Reviewed-by: Alberto Garcia <berto@igalia.com>

This test fails with -fuse:

$ tests/qemu-iotests/check -fuse -qcow2 290
[...]
290   fail       [16:49:10] [16:49:16]   5.3s                 output mismatch (see /home/kwolf/source/qemu/build-clang/scratch/qcow2-fuse-290/290.out.bad)
--- /home/kwolf/source/qemu/tests/qemu-iotests/290.out
+++ /home/kwolf/source/qemu/build-clang/scratch/qcow2-fuse-290/290.out.bad
@@ -77,7 +77,7 @@
 discard 65536/65536 bytes at offset 65536
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 # Compare disk usage of the 2 images
-disk_usage(t.qcow2) - disk_usage(t.qcow2.nounref) = 0
+disk_usage(fuse-t.qcow2) - disk_usage(fuse-t.qcow2.nounref) = 0
 # Check that images are still identical
 Images are identical.
 # Output of qemu-img map for the image with dropped reference
Failures: 290
Failed 1 of 1 iotests

Kevin