[libvirt] [PATCH libvirt sparse files under format=qcow2 v1 0/2] Problem: libvirt fails to create fully allocated qcow2 storage objects.
3:48 a.m.
From: Wim ten Have <wim.ten.have(a)oracle.com>
When virt-install requests to create fully allocated storage object when
the parameter sparse=no is set, libvirt doesn't allow that to happen
for qcow2 formatted files.
Regardless of its XML instuction request libvirt always targets its
filesystem object storage with preallocation=metadata if format=qcow2
is in effect. This results in sparse files which could cause problems
since total image storage potentially can overrun actual filesystem
available space.
Wim ten Have (2):
libvirt can't create fully allocated qcow2 formatted storage objects.
Adjust qemu-img test required to target with preallocation=falloc.
include/libvirt/libvirt-storage.h | 5 ++++-
src/storage/storage_util.c | 21 +++++++++++++++++----
.../qcow2-nocapacity-convert-prealloc.argv | 2 +-
3 files changed, 22 insertions(+), 6 deletions(-)
--
2.14.3
3:48 a.m.
New subject: [libvirt] [PATCH libvirt sparse files under format=qcow2 v1 1/2] libvirt can't create fully allocated qcow2 formatted storage objects.
From: Wim ten Have <wim.ten.have(a)oracle.com>
This patch adds support to qcow2 formatted storage objects by instructing
qemu-img to build them with preallocation=falloc whenever the XML
described storage <allocation> matches its <capacity>. For all other
cases the objects are built with preallocation=metadata.
Signed-off-by: Wim ten Have <wim.ten.have(a)oracle.com>
---
include/libvirt/libvirt-storage.h | 5 ++++-
src/storage/storage_util.c | 21 +++++++++++++++++----
2 files changed, 21 insertions(+), 5 deletions(-)
diff --git a/include/libvirt/libvirt-storage.h b/include/libvirt/libvirt-storage.h
index 413d9f6c4..2f22b388c 100644
--- a/include/libvirt/libvirt-storage.h
+++ b/include/libvirt/libvirt-storage.h
@@ -337,8 +337,11 @@ const char* virStorageVolGetName
(virStorageVolPtr vol);
const char* virStorageVolGetKey (virStorageVolPtr vol);
typedef enum {
+ VIR_STORAGE_VOL_CREATE_PREALLOC_NONE = 0 << 0,
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 */
} virStorageVolCreateFlags;
virStorageVolPtr virStorageVolCreateXML (virStoragePoolPtr pool,
diff --git a/src/storage/storage_util.c b/src/storage/storage_util.c
index b4aed0f70..7728fb63e 100644
--- a/src/storage/storage_util.c
+++ b/src/storage/storage_util.c
@@ -852,7 +852,7 @@ struct _virStorageBackendQemuImgInfo {
const char *path;
unsigned long long size_arg;
bool encryption;
- bool preallocate;
+ unsigned int preallocate;
const char *compat;
virBitmapPtr features;
bool nocow;
@@ -884,8 +884,15 @@ storageBackendCreateQemuImgOpts(virStorageEncryptionInfoDefPtr enc,
virStorageFileFormatTypeToString(info.backingFormat));
if (info.encryption)
virBufferAddLit(&buf, "encryption=on,");
- if (info.preallocate)
+
+ /* Handle various types of file-system storage pre-allocate sets.
+ */
+ if (info.preallocate & VIR_STORAGE_VOL_CREATE_PREALLOC_METADATA)
virBufferAddLit(&buf, "preallocation=metadata,");
+ else if (info.preallocate & VIR_STORAGE_VOL_CREATE_PREALLOC_FALLOC)
+ virBufferAddLit(&buf, "preallocation=falloc,");
+ else if (info.preallocate & VIR_STORAGE_VOL_CREATE_PREALLOC_FULL)
+ virBufferAddLit(&buf, "preallocation=full,");
}
if (info.nocow)
@@ -1183,7 +1190,7 @@ virStorageBackendCreateQemuImgCmdFromVol(virStoragePoolObjPtr pool,
.format = vol->target.format,
.path = vol->target.path,
.encryption = vol->target.encryption != NULL,
- .preallocate = !!(flags & VIR_STORAGE_VOL_CREATE_PREALLOC_METADATA),
+ .preallocate = VIR_STORAGE_VOL_CREATE_PREALLOC_NONE,
.compat = vol->target.compat,
.features = vol->target.features,
.nocow = vol->target.nocow,
@@ -1192,7 +1199,13 @@ virStorageBackendCreateQemuImgCmdFromVol(virStoragePoolObjPtr
pool,
};
virStorageEncryptionInfoDefPtr enc = NULL;
- virCheckFlags(VIR_STORAGE_VOL_CREATE_PREALLOC_METADATA, NULL);
+ if (flags) {
+ info.preallocate = (vol->target.capacity == vol->target.allocation) ?
+ VIR_STORAGE_VOL_CREATE_PREALLOC_FALLOC :
VIR_STORAGE_VOL_CREATE_PREALLOC_METADATA;
+ virCheckFlags((VIR_STORAGE_VOL_CREATE_PREALLOC_METADATA|
+ VIR_STORAGE_VOL_CREATE_PREALLOC_FALLOC|
+ VIR_STORAGE_VOL_CREATE_PREALLOC_FULL), NULL);
+ }
/* Treat output block devices as 'raw' format */
if (vol->type == VIR_STORAGE_VOL_BLOCK)
--
2.14.3
3:48 a.m.
New subject: [libvirt] [PATCH libvirt sparse files under format=qcow2 v1 2/2] Adjust qemu-img test required to target with preallocation=falloc.
From: Wim ten Have <wim.ten.have(a)oracle.com>
Signed-off-by: Wim ten Have <wim.ten.have(a)oracle.com>
---
tests/storagevolxml2argvdata/qcow2-nocapacity-convert-prealloc.argv | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tests/storagevolxml2argvdata/qcow2-nocapacity-convert-prealloc.argv
b/tests/storagevolxml2argvdata/qcow2-nocapacity-convert-prealloc.argv
index 9073b1b16..b151b9401 100644
--- a/tests/storagevolxml2argvdata/qcow2-nocapacity-convert-prealloc.argv
+++ b/tests/storagevolxml2argvdata/qcow2-nocapacity-convert-prealloc.argv
@@ -1,4 +1,4 @@
qemu-img convert -f raw -O qcow2 \
--o encryption=on,preallocation=metadata \
+-o encryption=on,preallocation=falloc \
/var/lib/libvirt/images/sparse.img \
/var/lib/libvirt/images/OtherDemo.img
--
2.14.3
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Wim Ten Have