erofs-utils: mkfs: support compact indexes for bigpcluster

This adds support to generate big pcluster compact indexes.

Different from non big pcluster, blkaddr recorded in each pack is
the 1st pcluster blkaddr with a valid CBLKCNT since we don't know
compressed block count of each pcluster when reading HEAD lcluster.

For more details, also see related kernel commits.

Link: https://lore.kernel.org/r/20210411034844.12673-9-xiang@kernel.org
Signed-off-by: Gao Xiang <xiang@kernel.org>
1 file changed