[libvirt] [PATCH libvirt sparse files under format=qcow2 v1 0/2] Problem: libvirt fails to create fully allocated qcow2 storage objects.
From: Wim ten Have <wim.ten.have@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
From: Wim ten Have <wim.ten.have@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@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
From: Wim ten Have <wim.ten.have@oracle.com> Signed-off-by: Wim ten Have <wim.ten.have@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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