Re: [libvirt] [PATCH v3 29/31] Introduce virStorageVol{Download, Upload}Flags

On 05/16/2017 10:04 AM, Michal Privoznik wrote: > These flags to APIs will tell if caller wants to use sparse > stream for storage transfer. At the same time, it's safe to > enable them in storage driver frontend and rely on our backends > checking the flags. This way we can enable specific flags only on > some specific backends, e.g. enable > VIR_STORAGE_VOL_DOWNLOAD_SPARSE_STREAM for filesystem backend but > not iSCSI backend. > > Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; > --- > include/libvirt/libvirt-storage.h | 9 +++++++++ > src/libvirt-storage.c | 4 ++-- > src/remote/remote_protocol.x | 2 ++ > src/storage/storage_driver.c | 4 ++-- > src/storage/storage_util.c | 10 ++++++---- > 5 files changed, 21 insertions(+), 8 deletions(-) > > diff --git a/include/libvirt/libvirt-storage.h b/include/libvirt/libvirt-storage.h > index 45ec72065..4517f713c 100644 > --- a/include/libvirt/libvirt-storage.h > +++ b/include/libvirt/libvirt-storage.h > @@ -346,11 +346,20 @@ virStorageVolPtr virStorageVolCreateXMLFrom (virStoragePoolPtr pool, > const char *xmldesc, > virStorageVolPtr clonevol, > unsigned int flags); > + > +typedef enum { > + VIR_STORAGE_VOL_DOWNLOAD_SPARSE_STREAM = 1 << 0, /* Use sparse stream */ > +} virStorageVolDownloadFlags; > + > int virStorageVolDownload (virStorageVolPtr vol, > virStreamPtr stream, > unsigned long long offset, > unsigned long long length, > unsigned int flags); > +typedef enum { > + VIR_STORAGE_VOL_UPLOAD_SPARSE_STREAM = 1 << 0, /* Use sparse stream */ > +} virStorageVolUploadFlags; > + /me wonders should the backend specific concerns be described in comments prior to each enum or is that too specific. Maybe it's more of a 'specific backends' that perform "file based manipulation" (rather than block based)... I dunno. I'll leave it to you though - the more documentation now while it's fresh in your mind the better. > int virStorageVolUpload (virStorageVolPtr vol, > virStreamPtr stream, > unsigned long long offset, > diff --git a/src/libvirt-storage.c b/src/libvirt-storage.c > index 05eec8a9d..64202998b 100644 > --- a/src/libvirt-storage.c > +++ b/src/libvirt-storage.c > @@ -1549,7 +1549,7 @@ virStorageVolCreateXMLFrom(virStoragePoolPtr pool, > * @stream: stream to use as output > * @offset: position in @vol to start reading from > * @length: limit on amount of data to download > - * @flags: extra flags; not used yet, so callers should always pass 0 > + * @flags: bitwise-OR of virStorageVolDownloadFlags > * > * Download the content of the volume as a stream. If @length > * is zero, then the remaining contents of the volume after > @@ -1613,7 +1613,7 @@ virStorageVolDownload(virStorageVolPtr vol, > * @stream: stream to use as input > * @offset: position to start writing to > * @length: limit on amount of data to upload > - * @flags: extra flags; not used yet, so callers should always pass 0 > + * @flags: bitwise-OR of virStorageVolUploadFlags > * > * Upload new content to the volume from a stream. This call > * will fail if @offset + @length exceeds the size of the I suppose for each you c(sh)ould have documented what the specific FLAG does and the expectations therein..