On Mon, Jul 20, 2020 at 1:33 PM Daniel P. Berrangé <berrange@xxxxxxxxxx> wrote: > > We already support a "nocow" flag for storage volumes, but this requires > extra work by the mgmt app or user when creating images on btrfs. We > want to "do the right thing" out of the box for btrfs. > > We achieve this by changint the storage pool code so that when creating > a storage pool we always try to disable COW on btrfs filesystems. We > then add an <cow state="yes|no"/> feature in the pool XML to let apps > override the default logic. > > The COW setting on the pool is inherited by any volumes. > > The main thing not solved here is that the default directory at > /var/lib/libvirt/images is created by the RPM itself, not by a > normal "pool-build" command. > > Fortunately it appears that virt-install will explicitly invoke a > storage pool build even if the directory already exists. > > Daniel P. Berrangé (4): > util: add a helper method for controlling the COW flag on btrfs > storage: convert to use virFileSetCOW > storage: attempt to disable COW by default > conf: add control over COW for storage pool directories > > docs/formatstorage.html.in | 25 +++++++ > docs/schemas/storagepool.rng | 30 ++++++++ > src/conf/storage_conf.c | 49 +++++++++++++ > src/conf/storage_conf.h | 8 +++ > src/libvirt_private.syms | 1 + > src/storage/storage_util.c | 46 +++++------- > src/util/virfile.c | 76 ++++++++++++++++++++ > src/util/virfile.h | 3 + > tests/storagepoolxml2xmlin/pool-dir-cow.xml | 10 +++ > tests/storagepoolxml2xmlout/pool-dir-cow.xml | 15 ++++ > tests/storagepoolxml2xmltest.c | 1 + > 11 files changed, 237 insertions(+), 27 deletions(-) > create mode 100644 tests/storagepoolxml2xmlin/pool-dir-cow.xml > create mode 100644 tests/storagepoolxml2xmlout/pool-dir-cow.xml > Patch series looks fine. Tested it and it seemed to automatically do what I expected on a fresh Fedora Rawhide system. Reviewed-by: Neal Gompa <ngompa13@xxxxxxxxx> -- 真実はいつも一つ！/ Always, there's only one truth!
