[libvirt] [PATCH] storage: allow metadata preallocation when creating qcow2 images
Currently the 'allocation' element is not used when creating new images with qemu-img. This patch interprets a non-zero value as a request to preallocate metadata when a qcow2 image is created. Bug: https://bugzilla.redhat.com/show_bug.cgi?id=684793 --- src/storage/storage_backend.c | 19 +++++++++++++------ 1 files changed, 13 insertions(+), 6 deletions(-) diff --git a/src/storage/storage_backend.c b/src/storage/storage_backend.c index 41a19a1..bf6f7cc 100644 --- a/src/storage/storage_backend.c +++ b/src/storage/storage_backend.c @@ -669,10 +669,15 @@ virStorageBackendCreateQemuImg(virConnectPtr conn, int imgformat = -1; virCommandPtr cmd = NULL; bool do_encryption = (vol->target.encryption != NULL); + bool preallocate = false; unsigned long long int size_arg; virCheckFlags(0, -1); + /* qcow2: preallocate metadata if requested allocation is non-zero */ + if (vol->allocation > 0 && vol->target.format == VIR_STORAGE_FILE_QCOW2) + preallocate = true; + const char *type = virStorageFileFormatTypeToString(vol->target.format); const char *backingType = vol->backingStore.path ? virStorageFileFormatTypeToString(vol->backingStore.format) : NULL; @@ -842,12 +847,14 @@ virStorageBackendCreateQemuImg(virConnectPtr conn, vol->target.path, NULL); virCommandAddArgFormat(cmd, "%lluK", size_arg); - if (do_encryption) { - if (imgformat == QEMU_IMG_BACKING_FORMAT_OPTIONS) { - virCommandAddArgList(cmd, "-o", "encryption=on", NULL); - } else { - virCommandAddArg(cmd, "-e"); - } + if (imgformat == QEMU_IMG_BACKING_FORMAT_OPTIONS && + (do_encryption || preallocate)) { + virCommandAddArg(cmd, "-o"); + virCommandAddArgFormat(cmd, "%s%s%s", do_encryption ? "encryption=on" : "", + (do_encryption && preallocate) ? "," : "", + preallocate ? "preallocation=metadata" : ""); + } else if (do_encryption){ + virCommandAddArg(cmd, "-e"); } } -- 1.7.8.6
On Thu, Nov 08, 2012 at 04:24:51PM +0100, Ján Tomko wrote:
Currently the 'allocation' element is not used when creating new images with qemu-img. This patch interprets a non-zero value as a request to preallocate metadata when a qcow2 image is created.
Bug: https://bugzilla.redhat.com/show_bug.cgi?id=684793 --- src/storage/storage_backend.c | 19 +++++++++++++------ 1 files changed, 13 insertions(+), 6 deletions(-)
diff --git a/src/storage/storage_backend.c b/src/storage/storage_backend.c index 41a19a1..bf6f7cc 100644 --- a/src/storage/storage_backend.c +++ b/src/storage/storage_backend.c @@ -669,10 +669,15 @@ virStorageBackendCreateQemuImg(virConnectPtr conn, int imgformat = -1; virCommandPtr cmd = NULL; bool do_encryption = (vol->target.encryption != NULL); + bool preallocate = false; unsigned long long int size_arg;
virCheckFlags(0, -1);
+ /* qcow2: preallocate metadata if requested allocation is non-zero */ + if (vol->allocation > 0 && vol->target.format == VIR_STORAGE_FILE_QCOW2) + preallocate = true; + const char *type = virStorageFileFormatTypeToString(vol->target.format); const char *backingType = vol->backingStore.path ? virStorageFileFormatTypeToString(vol->backingStore.format) : NULL;> @@ -842,12 +847,14 @@ virStorageBackendCreateQemuImg(virConnectPtr conn, vol->target.path, NULL); virCommandAddArgFormat(cmd, "%lluK", size_arg);
- if (do_encryption) { - if (imgformat == QEMU_IMG_BACKING_FORMAT_OPTIONS) { - virCommandAddArgList(cmd, "-o", "encryption=on", NULL); - } else { - virCommandAddArg(cmd, "-e"); - } + if (imgformat == QEMU_IMG_BACKING_FORMAT_OPTIONS && + (do_encryption || preallocate)) { + virCommandAddArg(cmd, "-o"); + virCommandAddArgFormat(cmd, "%s%s%s", do_encryption ? "encryption=on" : "", + (do_encryption && preallocate) ? "," : "", + preallocate ? "preallocation=metadata" : ""); + } else if (do_encryption){ + virCommandAddArg(cmd, "-e"); } }
I've thought about doing it this way before, but I always felt it was a bit of a gross hack. It would be nice to keep the 'allocation' element as purely describing the data sector allocation. I was recently wondering if we should just add a flag to the virStorageVolCreate like VIR_STORAGE_VOL_PREALLOC_METADATA Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|
On 11/08/2012 09:28 AM, Daniel P. Berrange wrote:
I've thought about doing it this way before, but I always felt it was a bit of a gross hack. It would be nice to keep the 'allocation' element as purely describing the data sector allocation. I was recently wondering if we should just add a flag to the virStorageVolCreate like
VIR_STORAGE_VOL_PREALLOC_METADATA
I agree that adding a new flag is cleaner; thankfully, virStorageVolCreateXML has a flags argument ready to use. -- Eric Blake eblake@redhat.com +1-919-301-3266 Libvirt virtualization library http://libvirt.org
On 11/08/12 23:10, Eric Blake wrote:
On 11/08/2012 09:28 AM, Daniel P. Berrange wrote:
I've thought about doing it this way before, but I always felt it was a bit of a gross hack. It would be nice to keep the 'allocation' element as purely describing the data sector allocation. I was recently wondering if we should just add a flag to the virStorageVolCreate like
VIR_STORAGE_VOL_PREALLOC_METADATA
I agree that adding a new flag is cleaner; thankfully, virStorageVolCreateXML has a flags argument ready to use.
I found an older thread [1] dealing with this and it seems it doesn't belong in the XML as a separate element either. I'll post another version with the flag. [1] https://www.redhat.com/archives/libvir-list/2012-May/msg00847.html
participants (3)
-
Daniel P. Berrange -
Eric Blake -
Ján Tomko