Re: [PATCH v9 32/34] qcow2: Allow preallocation and backing files if extended_l2 is set

2020-07-03 Thread Max Reitz
On 28.06.20 13:02, Alberto Garcia wrote: > Traditional qcow2 images don't allow preallocation if a backing file > is set. This is because once a cluster is allocated there is no way to > tell that its data should be read from the backing file. > > Extended L2 entries have individual allocation

[PATCH v9 32/34] qcow2: Allow preallocation and backing files if extended_l2 is set

2020-06-28 Thread Alberto Garcia
Traditional qcow2 images don't allow preallocation if a backing file is set. This is because once a cluster is allocated there is no way to tell that its data should be read from the backing file. Extended L2 entries have individual allocation bits for each subcluster, and therefore it is