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. Daniel _______________________________________________ Grub-devel mailing list [email protected] https://lists.gnu.org/mailman/listinfo/grub-devel
