On 05/17/2017 12:30 PM, Michal Privoznik wrote:
On 05/17/2017 05:42 PM, John Ferlan wrote:
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@redhat.com> --- 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..
How about this?
Fine - Reviewed-by: John Ferlan <jferlan@redhat.com> John
iff --git i/src/libvirt-storage.c w/src/libvirt-storage.c index 64202998b..35f9926d5 100644 --- i/src/libvirt-storage.c +++ w/src/libvirt-storage.c @@ -1555,6 +1555,13 @@ virStorageVolCreateXMLFrom(virStoragePoolPtr pool, * is zero, then the remaining contents of the volume after * @offset will be downloaded. * + * If VIR_STORAGE_VOL_DOWNLOAD_SPARSE_STREAM is set in @flags + * effective transmission of holes is enabled. This assumes using + * the @stream with combination of virStreamSparseRecvAll() or + * virStreamRecvFlags(stream, ..., flags = + * VIR_STREAM_RECV_STOP_AT_HOLE) for honouring holes sent by + * server. + * * This call sets up an asynchronous stream; subsequent use of * stream APIs is necessary to transfer the actual data, * determine how much data is successfully transferred, and @@ -1621,6 +1628,11 @@ virStorageVolDownload(virStorageVolPtr vol, * will be raised if an attempt is made to upload greater * than @length bytes of data. * + * If VIR_STORAGE_VOL_UPLOAD_SPARSE_STREAM is set in @flags + * effective transmission of holes is enabled. This assumes using + * the @stream with combination of virStreamSparseSendAll() or + * virStreamSendHole() to preserve source file sparseness. + * * This call sets up an asynchronous stream; subsequent use of * stream APIs is necessary to transfer the actual data, * determine how much data is successfully transferred, and
Michal