On Tuesday 30 June 2015 06:20 PM, Ján Tomko wrote:
On Fri, Jun 26, 2015 at 05:05:11PM +0530, Prerna Saxena wrote:
Libvirt periodically refreshes all volumes in a storage pool, including the volumes being cloned. While cloning a storage volume from parent, we drop pool locks. Subsequent volume refresh sometimes changes allocation for an ongoing copy, and leads to corrupt images. Fix: Introduce a shadow volume that isolates the volume object under refresh from the base which has a copy ongoing.
Signed-off-by: Prerna Saxena <prerna@linux.vnet.ibm.com> --- src/storage/storage_driver.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-)
ACK
diff --git a/src/storage/storage_driver.c b/src/storage/storage_driver.c index 57060ab..41de8df 100644 --- a/src/storage/storage_driver.c +++ b/src/storage/storage_driver.c @@ -1898,7 +1898,7 @@ storageVolCreateXMLFrom(virStoragePoolPtr obj, { virStoragePoolObjPtr pool, origpool = NULL; virStorageBackendPtr backend; - virStorageVolDefPtr origvol = NULL, newvol = NULL; + virStorageVolDefPtr origvol = NULL, newvol = NULL, shadowvol = NULL; virStorageVolPtr ret = NULL, volobj = NULL; unsigned long long allocation; int buildret; @@ -2010,6 +2010,15 @@ storageVolCreateXMLFrom(virStoragePoolPtr obj, if (backend->createVol(obj->conn, pool, newvol) < 0) goto cleanup;
+ /* Make a shallow copy of the 'defined' volume definition, since the + * original allocation value will change as the user polls 'info', + * but we only need the initial requested values + */ + if (VIR_ALLOC(shadowvol) < 0) + goto cleanup; + + memcpy(shadowvol, newvol, sizeof(*newvol)); + pool->volumes.objs[pool->volumes.count++] = newvol; volobj = virGetStorageVol(obj->conn, pool->def->name, newvol->name, newvol->key, NULL, NULL); @@ -2029,7 +2038,7 @@ storageVolCreateXMLFrom(virStoragePoolPtr obj, virStoragePoolObjUnlock(origpool); }
- buildret = backend->buildVolFrom(obj->conn, pool, newvol, origvol, flags); + buildret = backend->buildVolFrom(obj->conn, pool, shadowvol, origvol, flags);
newvol->target.allocation should also use the value from shadowvol. I have made the adjustment and pushed the patch.
Jan
Hi Jan, Thanks. Could you also take a look at the second patch in this series ? Regards, -- Prerna Saxena Linux Technology Centre, IBM Systems and Technology Lab, Bangalore, India