01.08.2019 18:12, Max Reitz wrote: > Hi, > > In a discussion with Vladimir today, we noticed that the backup job > currently is pretty broken when using copy offloading. I don’t know > about you, but my local filesystem (XFS) supports copy offloading, so > the job uses it automatically. That means, that backup is broken and > has been broken for a year on my local FS. > > The last working version was 2.12, so this isn’t a regression in 4.1. > We could thus justify moving it to 4.2. But I think this should really > go into 4.1, because this is not really an edge case and as far as I > know users cannot do anything to prevent the backup job from performing > copy offloading if the system and all involved block drivers support it. > I just wonder why nobody has noticed... >
Agree. And if this goes into 4.1, I suggest to add [PATCH 2/3] block/backup: disable copy_range for compressed backup as for now compressed backup just don't compress anything on FS with copy offloading supported. > > Max Reitz (2): > backup: Copy only dirty areas > iotests: Test backup job with two guest writes > > block/backup.c | 13 +++++++++++-- > tests/qemu-iotests/056 | 34 ++++++++++++++++++++++++++++++++++ > tests/qemu-iotests/056.out | 4 ++-- > 3 files changed, 47 insertions(+), 4 deletions(-) > -- Best regards, Vladimir
