qcow2: Add subcluster support to zero_in_l2_slice()
commit205fa507508e1f8caa79325bafb3cd2ae8814125
authorAlberto Garcia <berto@igalia.com>
Fri, 10 Jul 2020 16:13:04 +0000 (10 18:13 +0200)
committerMax Reitz <mreitz@redhat.com>
Tue, 25 Aug 2020 06:33:20 +0000 (25 08:33 +0200)
tree169261bc86f926ef299717637ba920fc77a0468a
parent3f9c6b3b1f48d6c59d27df658f03792b857d7b55
qcow2: Add subcluster support to zero_in_l2_slice()

The QCOW_OFLAG_ZERO bit that indicates that a cluster reads as
zeroes is only used in standard L2 entries. Extended L2 entries use
individual 'all zeroes' bits for each subcluster.

This must be taken into account when updating the L2 entry and also
when deciding that an existing entry does not need to be updated.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <b61d61606d8c9b367bd641ab37351ddb9172799a.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
block/qcow2-cluster.c