[PATCH v3 0/4] erofs-utils: implement the FULLDATA rebuild mode

[Lucas Karpinski]

On 2026-04-14 10:07 p.m., Gao Xiang wrote:
> 
> 
> On 2026/4/15 03:10, Lucas Karpinski wrote:
>> Currently, erofs-utils supports backing blobs for multi-image setups. 
>> This
>> implements the FULLDATA import which allows for the merging of multiple
>> source images into a single self-contained erofs image.
>>
>> To optimize the rebuild process, erofs_io_xcopy() is used to leverage the
>> copy_file_range(2) if available. This bypasses userspace buffering and
>> enables kernel side data transfers.
>>   Verification: Built same image with default rebuild and rebuild with
>> FULLDATA. Then ran F-i-f/tdiff comparing the two.
>>
>> changes in v3:
>> - adhere to uniaddress semantics.
>> - take advantage of existing infrastructure which allows us to drop a
>>    significant amount of complexity + code.
>>
>> changes in v2:
>> - reworked erofs_rebuild_load_trees_full into
>>    erofs_mkfs_rebuild_load_trees.
>> - removed --merge option (use --clean=data instead).
>> - updated man.
>>
>> Signed-off-by: Lucas Karpinski <lkarpinski at nvidia.com>
> 
> Overally looks good to me, will apply to -experimental branch.
> 
> ... Would you mind taking some time working on some tests
> in experimental-tests branch?
> 
> Thanks,
> Gao Xiang

Yes, I'll work on adding some tests.

Regards,
Lucas