To prevent a race with a background GC operation, do not allow deletion
of backups who's index might currently be referenced as the "known chunk
list" for successive backups. Otherwise the GC could delete chunks it
thinks are no longer referenced, while at the same time telling the
client that it doesn't need to upload said chunks because they already
exist.
Additionally, prevent deletion of whole backup groups, if there are
snapshots contained that appear to be currently in-progress. This is
currently unlikely to trigger, as that function is only used for sync
jobs, but it's a useful safeguard either way.
Deleting a single snapshot has a 'force' parameter, which is necessary
to allow deleting incomplete snapshots on an aborted backup. Pruning
also sets force=true to avoid the check, since it calculates which
snapshots to keep on its own.
To avoid code duplication, the is_finished method is factored out.
Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>
And make verify_crc private for now. We always call load_from_reader() to
verify the CRC.
Also add load_chunk() to datastore.rs (from chunk_store::read_chunk())
We support using an ext4 mountpoint directly as datastore and even do
so ourself when creating one through the disk manage code.
Such ext4 ountpoints have a lost+found directory which only root can
traverse into. As the GC list images is done as backup:backup user
walkdir gets an error.
We cannot ignore just all permission errors, as they could lead to
missing some backup indexes and thus possibly sweeping more chunks
than desired. While *normally* that should not happen through our
stack, we had already user report that they do rsyncs to move a
datastore from old to new server and got the permission wrong.
So for now be still very strict, only allow a "lost+found" directory
as immediate child of the datastore base directory, nothing else.
If deemed safe, this can always be made less strict. Possibly by
filtering the known backup-types on the highest level first.
Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
last_successful_backup: Returns the time of the last successful backup
group_path: Returns the absolute path for a backup_group
snapshot_path: Returns the absolute path for a backup_dir
