Hi Lucas, On Mon, Mar 09, 2026 at 12:38:20PM -0400, Lucas Karpinski wrote: > This patch introduces experimental support for merging multiple source > images in mkfs. Each source image becomes a directory directly under root > and keeps its UUID stored as a device table tag. The raw block data from > each source is copied using erofs_copy_file_range. We preserve the file > metadata and layout (FLAT_PLAIN and FLAT_INLINE). Symlink paths are handled > by reading and copy link targets. > > This does not yet support chunk-based files at this time or compressed > images. > > Signed-off-by: Lucas Karpinski <[email protected]>
Thanks for your effort, I finally get the time to look into this new feature. So you'd like to cleanly rebuild a new filesystem with given sub filesystems? I think first, yes, that is what `--clean=data` is used instead. But I think uniaddr shouldn't be used like this (uniaddr is used to give a flat mapping for multiple blobs, in addition to the device id + offset ones, which is mainly used for compressed data multi blob support), instead, I think we need to find a way to wrap up the data source into a valid vfile (so that erofs_pread can be called to get the source data) , and make erofs_mkfs_job_write_file() to write (un)compressed data from its source instead. Thanks, Gao Xiang
