Re: bcachefs - snapshots

[Bernd Schubert]

On 9/27/21 3:49 AM, Kent Overstreet wrote:
> Snapshots have been merged! 9 months of work and 3k lines of new code, finally
> released. Some highlights:
> 
>  - btrfs style subvolumes & snapshots interface
>  - snapshots are writeable
>  - highly scalable: number of snapshots is limited only by your disk space
>  - highly space efficient: no internal fragmentation issues
> 
> Design doc here: https://bcachefs.org/Snapshots/
> 
> The core functionality is complete - snapshot creation and deletion works, fsck
> changes are done (most of the complexity was in making fsck work without
> O(number of snapshots) performance - tricky). Everything else is a todo item:
> 
>  - still need to export different st_dev for files in different subvolumes
>    (we'll never allocate a new inode with an inode number that collides with an
>    inode inother subvolume - but snapshots will naturally result in colliding
>    inode numbers)

With my limited high level view on it - shouldn't you discuss with Neil
about a solution and to avoid going the btrfs route for colliding inode
numbers?