On Fri, Sep 05, 2025 at 10:32:24PM +0200, Daniel Kiper wrote: > On Tue, Sep 02, 2025 at 02:45:56PM +0800, Michael Chang via Grub-devel wrote: > > This patch series adds support for storing the GRUB environment block in > > a reserved area of the Btrfs header. On copy on write filesystems such > > as Btrfs, the normal file based envblk cannot be updated safely at > > runtime because block addresses are not stable. The reserved area > > provides a fixed location that GRUB can write directly, allowing > > commands such as grub-reboot and savedefault to work on Btrfs volumes. > > > > The series proceeds in small chunks to keep each change buildable and > > easier to review. The first patches add new data structures and helpers > > for creating, opening, and writing an environment block in the reserved > > area. Later patches update set_variables, unset_variables, and > > list_variables so they can use the external block when it is present. An > > entry is added to the Btrfs header to reserve space at 256 KiB for the > > environment block. Finally, grub.cfg is modified so that load_env and > > save_env use the external block automatically when env_block is defined. > > > > Michael Chang (8): > > util/grub-editenv: add basic structures and probe call for external > > envblk > > util/grub-editenv: add fs_envblk open helper > > util/grub-editenv: add fs_envblk write helper > > util/grub-editenv: wire set_variables to optional fs_envblk > > util/grub-editenv: wire unset_variables to optional fs_envblk > > util/grub-editenv: wire list_variables to optional fs_envblk > > btrfs: add environment block to reserved header area > > 00_header.in: wire grub.cfg to use env_block when present > > I have stopped reviewing the series at the patch #4. Some code requires > clarification. Additionally, please add a description of the new feature > to the GRUB documentation.
Thanks a lot for your time and effort in reviewing the patches. I will add a section in the documentation to better describe the feature in the next version. Thanks, Michael > > Daniel _______________________________________________ Grub-devel mailing list [email protected] https://lists.gnu.org/mailman/listinfo/grub-devel
