Introduce restic.Chunker and ChunkerFactory interfaces with a
repository-backed implementation. The archiver obtains chunkers via
ChunkerFactory() from the repository.
Update the chunker dependency. Move the chunk memory handling into the
fileSaver. This minimizes the logic required in a chunker
implementation.
readNextChunk is a direct derivative of Chunker.Next.
The treeCache in SnapshotsDir was never cleared when snapshots were
reloaded. This caused the "latest" symlink to keep pointing to the
previous snapshot even after new snapshots were added.
Add a generation counter to SnapshotsDirStructure that is incremented
whenever the directory structure is rebuilt (in makeDirs). The
treeCache checks this generation on each lookup and resets itself
when the generation changes, ensuring cached nodes (including symlinks)
are refreshed after a snapshot reload.
Mounting a local repository onto its own directory caused the FUSE
server to read its own backend files through the mount it had just
created, deadlocking the kernel. `umount` then reported "Device or
resource busy" and recovery required a reboot that took several
minutes. The same shape occurs when the mountpoint is nested inside
the repository directory, or when the repository directory is nested
inside the mountpoint.
The mount command now resolves both paths via filepath.Abs and
filepath.EvalSymlinks and refuses with a fatal error if either path
equals or contains the other. The check runs before the repository
lock is acquired so an overlap fails fast. Only the local backend is
checked; remote backends cannot shadow the mountpoint directory.
The treeCache in SnapshotsDir was never cleared when snapshots were
reloaded. This caused the "latest" symlink to keep pointing to the
previous snapshot even after new snapshots were added.
Add a generation counter to SnapshotsDirStructure that is incremented
whenever the directory structure is rebuilt (in makeDirs). The
treeCache checks this generation on each lookup and resets itself
when the generation changes, ensuring cached nodes (including symlinks)
are refreshed after a snapshot reload.