[Qemu-devel] Doubt about COW feature of QCOW2

[Furquan Shaikh]

Hello All,
I had a doubt about the COW implementation of QCOW2.

Suppose two clusters point to the same address, then in that case, the QCOW_OFLAG_COPIED is cleared in the l2 entries for both the clusters. 
Now suppose a write is made to any one of the clusters, then how is the other cluster identified, in order to set the QCOW_OFLAG_COPIED since only reference is left.

Thanks in advance,
Furquan