On 18/09/2018 19.15, Goffredo Baroncelli wrote: >> b. The bootloader code, would have to have sophisticated enough Btrfs >> knowledge to know if the grubenv has been reflinked or snapshot, >> because even if +C, it may not be valid to overwrite, and COW must >> still happen, and there's no way the code in GRUB can do full blow COW >> and update a bunch of metadata. > And what if GRUB ignore the possibility of COWing and overwrite the data ? Is it a so big problem that the data is changed in all the snapshots ? > It would be interested if the same problem happens for a swap file..... I gave a look to the Sandoval's patches about implementing swap on BTRFS. This patch set prevents the subvolume containing the swapfile to be snapshot-ted (and the file to be balanced and so on...); what if we would add the same constraint to the grubenv file ? BR G.Baroncelli -- gpg @keyserver.linux.it: Goffredo Baroncelli <kreijackATinwind.it> Key fingerprint BBF5 1610 0B64 DAC6 5F7D 17B2 0EDA 9B37 8B82 E0B5
