Detailed step by step instructions to reproduce the problem
The import cant be done cause the btrfs is using space_cache=v2. After cleaning space cache the import works!
we’re at kernel 4.12@rockstor right now. Imho space_cache=v2 is mature enough to be used. So plz add support for the space_cache=v2 mount option! Even make it default for new installs.
This is something I can’t agree with however. We essentially follow the lead re btrfs devs on all defaults so upon our elrepo kernel-ml version adopting this by default then as do we. I don’t think it is wise to deviate from the developer ascribed defaults. Apologies if I have the wrong end of the stick here.
Hope that helps and thanks for your ongoing contribution.
another suggestion: How about giving the user the opportunity to choose with space_cache option to use?
a dropdown like for the compression option. the dropdown must have at least 3 settings space_cache, space_cache=v2 and clear_cache (this must be set with option no_space_cache, so users can safely switch from space_cache=v1 to space_cache=v2 without breaking anything)