With this, previous snapshots (far relations) are still listed when
restoring a snapshot.
Example (S = source subvolume, readwrite):
After 3 snapshots:
A->S, B->S, C->S
Restore B: `btrfs subvol delete S; btrfs subvol snapshot B S'`
A->S, B->S, C->S, S'->B
Previous implementation would show now snapshots for S', as no
snapshot has parent_uuid=S'.
New implementation shows A, B, C as snapshots for S', as orphaned
siblings (A, B, C pointing to deleted S) are also related.
Makes sure that if, for whatever reason, a subvolume having correct
btrbk name scheme does NOT share any extents with previous snapshots
is never used as parent.
Note that if a related parent is found, the unrelated closest
older/newer (by btrbk timestamp) subvolumes are still added as clone
sources.
Preferences for parent (and required clone sources):
1. closest older in snapdir (by btrbk timestamp), related
2. closest older related (by cgen)
3. closest newer related (by cgen)
4. closest older in snapdir (by btrbk timestamp)
5. closest newer in snapdir (by btrbk timestamp)
Note: prefering 1 over 2 helps keeping parent-chain within droot on
target (assuming that btrfs always uses correlated parent on
btrfs-receive).
This will e.g. add a clone source on "btrbk resume", if both older AND
newer snapshot/backup pairs exists.
Also makes sure that the closest older btrbk snapshot is always added
as clone source, even if another related subvolume has newer cgen.
Old implementation was missing last readonly parent in chain, as well
as orphaned siblings.
Also sort all by cgen, not by distance, then cgen.
Also skip self.
Allowed values for "incremental_resolve":
- "mountpoint" (default): Use parents in the filesystem tree below
mount points of source `<volume-directory>/<snapshot-dir>` and
target `<target-directory>`.
- "directory": Use parents strictly below source/target
directories. Useful when restricting access, e.g. when using
ssh_filter_btrbk.sh.
- "_all_accessible" (experimental): Use parents from all mount points.
Note that using "_all_accessible" causes btrfs-progs to fail:
- btrfs send -p: "ERROR: not on mount point: /path/to/mountpoint"
- btrfs receive: "ERROR: parent subvol is not reachable from inside the root subvol"
see also: https://github.com/kdave/btrfs-progs/issues/96
Build check hash within btr_tree node instead per URL. This makes it
aware of shared btr_tree (different hostname:port pointing to same
btrfs filesystem).
Common virtual machine setups have multiple volume sections with same
host, but distinct port numbers for each machine.
- make caches dependent on MACHINE_ID instead of HOST
- append port number to URL
- add MACHINE_ID to vinfo
- use MACHINE_ID where applicable
This even works if virtual machines share the same btrfs filesystems:
If a equal UUID is found on distinct machines, btr_tree() will return
the already present tree, in order to be consistent after node
injections.
Setting the ssh port directly in the "volume" / "target" config lines
adds the possibility to have a create a unique "hostname:port"
identifier (preparatory for MACHINE_ID to distinguish virtual machines
on same host with different ports.)
btrbk <= 0.27.2 does not print "target_rsh" and "target_type" when
called with --format=raw, see $table_formats{resolved}. This is fixed
in 0.28.0.
Hardcoding target_type=send-receive is not so bad, as for raw targets
btrbk-verify complains first with:
btrbk-verify: missing required variable "target_rsh" in btrbk --format=raw line
So we should not run rsync (which is not really a problem, rsync just
fails with "not a directory").
Compare files and attributes by checksum, using rsync(1) in dry-run
mode with all preserve options enabled.
Resolves snapshot/backup pairs by evaluating the output of
"btrbk list latest [filter...]".
Restrictions:
- ".d..t...... ./" lines are ignored by default:
Root folder timestamp always differ.
- "cd+++++++++ .*" lines are ignored by default:
Nested subvolumes appear as new empty directories.
- btrbk raw targets are skipped
- rsync needs root in most cases (see --ssh-* options)
When called from another script, we dont want the help message printed
on errors. E.g. when running something like:
btrbk list snapshots -q filter_which_does_not_match
While on traditional UNIX the documentation (especially the man pages)
are gzip'ed, modern distros have helpers to compress it.
This patch adds an option to disable compression:
make COMPRESS=no
When configuring "target" in a global (or "volume") context, and
overriding target_preserve_min in "subvolume" section, the scheduler
has undefined behavior (mixing up the "min" values).
Fixed by returning a copy of the preserve hash in
config_preserve_hash().
It is possible that the subvolume path is not accessible by the user
calling btrbk. When resolving mount points, "readlink" is used on the
path, which also needs to be wrapped with "sudo".
Axel Burri