btrfs-tree-log · shipping · also Btrfs log tree

Btrfs tree log

The Btrfs tree log is a per-subvolume recovery structure that can persist file or directory changes for fsync without a full filesystem transaction commit.

The Linux v6.16 fsync path can also fall back to a full commit. Mount-time replay can write even on a read-only mount. Upstream Linux 6.16 removed standalone nologreplay; rescue=nologreplay remains available and requires read-only mounting. Suppressing replay can hide recent logged changes, while btrfs rescue zero-log clears the log and may lose them. [2] [3] [4] [6]

Relations

related

btrfs, copy-on-write, fsync, data-scrubbing

Limitations

• A source-registration audit does not test actual recovery or distribution backports. [5]
• notreelog and rescue=nologreplay control different flags; rescue=all additionally disables checksum checks. [5]

Citations

1. Linux v6.16: Btrfs tree-log.c, design comment and replay implementation (accessed 2026-10-15)
2. Linux v6.16: Btrfs file.c, btrfs_sync_file and transaction-commit fallback (accessed 2026-10-15)
3. Btrfs documentation: btrfs(5), tree logging and rescue mount options (accessed 2026-10-15)
4. Btrfs feature-by-version: rescue in 5.9 and standalone nologreplay removal in 6.16 (accessed 2026-10-15)
5. Linux v6.16: Btrfs super.c, option registration and read-only checks (accessed 2026-10-15)
6. Btrfs documentation: btrfs-rescue(8), zero-log and possible loss of changes (accessed 2026-10-15)
7. Hesela: Btrfs tree logs, read-only replay and version boundaries (accessed 2026-10-15)

JSON: /data/terms/btrfs-tree-log.json