From: Prerna Saxena <prerna(a)linux.vnet.ibm.com>
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>
Signed-off-by: Ján Tomko <jtomko(a)redhat.com>
---
src/storage/storage_backend.c | 23 ++++++++++++++---------
src/storage/storage_driver.c | 5 -----
2 files changed, 14 insertions(+), 14 deletions(-)
diff --git a/src/storage/storage_backend.c b/src/storage/storage_backend.c
index c71545c..bab81e3 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,
@@ -401,6 +401,12 @@ createRawFile(int fd, virStorageVolDefPtr vol,
int ret = 0;
unsigned long long pos = 0;
+ /* If the new allocation is lower than the capacity of the orignal file,
+ * the cloned volume will be sparse */
+ if (inputvol &&
+ vol->target.allocation < inputvol->target.capacity)
+ need_alloc = false;
+
/* Seek to the final size, so the capacity is available upfront
* for progress reporting */
if (ftruncate(fd, vol->target.capacity) < 0) {
@@ -420,7 +426,7 @@ 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) {
@@ -433,21 +439,20 @@ createRawFile(int fd, virStorageVolDefPtr vol,
}
#endif
-
if (inputvol) {
- unsigned long long remain = vol->target.allocation;
+ unsigned long long remain = inputvol->target.capacity;
/* 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);
-
ret = virStorageBackendCopyToFD(vol, inputvol, fd, &remain,
- want_sparse, reflink_copy);
+ !need_alloc, reflink_copy);
if (ret < 0)
goto cleanup;
- pos = vol->target.allocation - remain;
+ /* If the new allocation is greater than the original capacity,
+ * but fallocate failed, fill the rest with zeroes.
+ */
+ pos = inputvol->target.capacity - remain;
}
if (need_alloc) {
diff --git a/src/storage/storage_driver.c b/src/storage/storage_driver.c
index e600514..ba27acf 100644
--- a/src/storage/storage_driver.c
+++ b/src/storage/storage_driver.c
@@ -1975,11 +1975,6 @@ storageVolCreateXMLFrom(virStoragePoolPtr obj,
if (newvol->target.capacity < origvol->target.capacity)
newvol->target.capacity = origvol->target.capacity;
- /* Make sure allocation is at least as large as the destination cap,
- * to make absolutely sure we copy all possible contents */
- if (newvol->target.allocation < origvol->target.capacity)
- newvol->target.allocation = origvol->target.capacity;
-
if (!backend->buildVolFrom) {
virReportError(VIR_ERR_NO_SUPPORT,
"%s", _("storage pool does not support"
--
2.3.6