Re: [libvirt] [PATCH v1 1/2] storage: extend preallocation flags support for qemu-img

On 04/03/2018 04:14 PM, Wim Ten Have wrote: > From: Wim ten Have <wim.ten.have(a)oracle.com&gt; > > This patch adds support to qcow2 formatted filesystem object storage by > instructing qemu-img to build them with preallocation=falloc whenever the > XML described storage <allocation> matches its <capacity>. For all other > cases the filesystem stored objects are built with preallocation=metadata. > > Signed-off-by: Wim ten Have <wim.ten.have(a)oracle.com&gt;

> VIR_STORAGE_VOL_CREATE_PREALLOC_METADATA = 1 << 0, > - VIR_STORAGE_VOL_CREATE_REFLINK = 1 << 1, /* perform a btrfs lightweight copy */ > + VIR_STORAGE_VOL_CREATE_PREALLOC_FALLOC = 1 << 1, > + VIR_STORAGE_VOL_CREATE_PREALLOC_FULL = 1 << 2, > + VIR_STORAGE_VOL_CREATE_REFLINK = 1 << 3, /* perform a btrfs lightweight copy */ This is not. Imagine there's a mgmt application already written and compiled which calls: virStorageVolCreateXML(flags = VIR_STORAGE_VOL_CREATE_REFLINK); Because it is already compiled it is effectively calling: virStorageVolCreateXML(flags = 1); and everything works. However, if this change would be merged, the mgmt application would be still making the same call but now it would have different semantic, because you are changing the numbering. So effectively mgmt app would be calling virStorageVolCreateXML(flags = VIR_STORAGE_VOL_CREATE_PREALLOC_FALLOC) which is obviously wrong. We can not expect mgmt applications to be recompiled every time there's a new release of libvirt.

Also, storagevolxml2argvtest is failing after this change. See 'make check'.

Michal -- libvir-list mailing list libvir-list(a)redhat.com https://www.redhat.com/mailman/listinfo/libvir-list