On 4/19/19 9:05 AM, Vladimir Sementsov-Ogievskiy wrote: > This test checks bug in qcow2_process_discards, fixed by previous > commit. > > Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com> > ---
> +# This test checks that qcow2_process_discards does not truncate a discard > +# request > 2G. > +# To reproduce bug we need to overflow int by one sequential discard, so we > +# need size > 2G, bigger cluster size (as with default 64k we may have > maximum > +# of 512M sequential data, corresponding to one L1 entry), and we need some > +# data of the beginning of the disk mapped to the end of file to prevent > +# bdrv_co_truncate(bs->file) call in qcow2_co_truncate(), which may success s/may success/might succeed/ > +# anyway. > + > +size=2100M > +IMGOPTS="cluster_size=1M,preallocation=metadata" > + > +_make_test_img $size > +$QEMU_IO -c 'discard 0 10M' -c 'discard 2090M 10M' \ > + -c 'write 2090M 10M' -c 'write 0 10M' "$TEST_IMG" | _filter_qemu_io > + > +# Check that our trick with swapping first and last 10M chunks succeeded. > +# Otherwise test will may pass even if bdrv_pdiscard() fails in > +# qcow2_process_discards() > +$QEMU_IMG map "$TEST_IMG" | _filter_testdir > +$QEMU_IMG info "$TEST_IMG" | grep size | _filter_testdir Nice - that's a lot faster than v1! And makes the test fit in the quick group after all. > + > +$QEMU_IMG -T 'qcow2_process_discards_failed*' resize --shrink "$TEST_IMG" 5M However, I'm quite certain that trace output is not reliable in iotests. Depending on configure options, traces might not be enabled at all, or might not go to stderr. Drop the -T '...'. Even without the trace line, > + > +$QEMU_IMG info "$TEST_IMG" | grep size | _filter_testdir this second image info is sufficient to prove whether the resize had an effect (post-patch) or exposes the bug (without patch 2/3). That is, applying this patch but not 2/3, I see this (with my cleanups to qemu-img info in place, from Kevin's block-next branch): +++ /home/eblake/qemu/tests/qemu-iotests/250.out.bad 2019-04-22 08:52:26.072968731 -0500 @@ -14,8 +14,9 @@ virtual size: 2.05 GiB (2202009600 bytes) disk size: 24 MiB cluster_size: 1048576 +18274@1555941145.999195:qcow2_process_discards_failed_region offset 0x500000 bytes 0x82a00000 ret -5 Image resized. virtual size: 5 MiB (5242880 bytes) -disk size: 9.01 MiB +disk size: 19 MiB where the trace did indeed show show that we had a bug, but where even without the trace, the difference in size between 19M with incomplete discards vs. 9M with patch 2/3 is enough to show that patch 2/3 fixes a bug. > +virtual size: 2.1G (2202009600 bytes) > +disk size: 24M > +cluster_size: 1048576 > +Image resized. > +virtual size: 5.0M (5242880 bytes) > +disk size: 9.0M > +cluster_size: 1048576 When Kevin's block-next branch is applied, you'll need this squashed in: diff --git a/tests/qemu-iotests/250.out b/tests/qemu-iotests/250.out index 37e37f0c9e7..d1c1c7180b5 100644 --- a/tests/qemu-iotests/250.out +++ b/tests/qemu-iotests/250.out @@ -11,11 +11,11 @@ wrote 10485760/10485760 bytes at offset 0 Offset Length Mapped to File 0 0xa00000 0x82f00000 TEST_DIR/t.qcow2 0x82a00000 0xa00000 0x500000 TEST_DIR/t.qcow2 -virtual size: 2.1G (2202009600 bytes) -disk size: 24M +virtual size: 2.05 GiB (2202009600 bytes) +disk size: 24 MiB cluster_size: 1048576 Image resized. -virtual size: 5.0M (5242880 bytes) -disk size: 9.0M +virtual size: 5 MiB (5242880 bytes) +disk size: 9.01 MiB cluster_size: 1048576 *** done With the updated output to match changes to qemu-img output, the grammar fixes, and with the -T option removed, Reviewed-by: Eric Blake <ebl...@redhat.com> Tested-by: Eric Blake <ebl...@redhat.com> -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org
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