Re: [libvirt] [PATCH 2/2] Storage : Fix cloning of raw, sparse volumes

From: Prerna Saxena <prerna(a)linux.vnet.ibm.com&gt; Date: Mon, 22 Jun 2015 02:54:32 -0500 When virsh vol-clone is attempted on a raw file where capacity > allocation, the resulting cloned volume has a size that matches the virtual-size of the parent; in place of matching its actual, disk size. This patch fixes the cloned disk to have same _allocated_size_ as the parent file from which it was cloned. Ref: http://www.redhat.com/archives/libvir-list/2015-May/msg00050.html Also fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1130739 Signed-off-by: Prerna Saxena <prerna(a)linux.vnet.ibm.com&gt; --- src/storage/storage_backend.c | 10 +++++----- src/storage/storage_driver.c | 5 ----- 2 files changed, 5 insertions(+), 10 deletions(-) diff --git a/src/storage/storage_backend.c b/src/storage/storage_backend.c index ce59f63..c99b718 100644 --- a/src/storage/storage_backend.c +++ b/src/storage/storage_backend.c @@ -342,7 +342,7 @@ virStorageBackendCreateBlockFrom(virConnectPtr conn ATTRIBUTE_UNUSED, goto cleanup; } - remain = vol->target.allocation; + remain = vol->target.capacity; if (inputvol) { int res = virStorageBackendCopyToFD(vol, inputvol, @@ -397,7 +397,7 @@ createRawFile(int fd, virStorageVolDefPtr vol, virStorageVolDefPtr inputvol, bool reflink_copy) { - bool need_alloc = true; + bool need_alloc = !(inputvol && (inputvol->target.capacity > inputvol->target.allocation));

int ret = 0; unsigned long long remain; @@ -420,7 +420,7 @@ createRawFile(int fd, virStorageVolDefPtr vol, * to writing zeroes block by block in case fallocate isn't * available, and since we're going to copy data from another * file it doesn't make sense to write the file twice. */ - if (vol->target.allocation) { + if (vol->target.allocation && need_alloc) { if (fallocate(fd, 0, 0, vol->target.allocation) == 0) { need_alloc = false; } else if (errno != ENOSYS && errno != EOPNOTSUPP) { @@ -433,14 +433,14 @@ createRawFile(int fd, virStorageVolDefPtr vol, } #endif - remain = vol->target.allocation; + remain = vol->target.capacity; if (inputvol) { /* allow zero blocks to be skipped if we've requested sparse * allocation (allocation < capacity) or we have already * been able to allocate the required space. */ bool want_sparse = !need_alloc || - (vol->target.allocation < inputvol->target.capacity); + (inputvol->target.allocation < inputvol->target.capacity);