zrepl/endpoint
Christian Schwarz bbdc6f5465
fix handling of tenative cursor presence if protection strategy doesn't use it (#714)
Before this PR, we would panic in the `check` phase of `endpoint.Send()`'s `TryBatchDestroy` call in the following cases: the current protection strategy does NOT produce a tentative replication cursor AND
  * `FromVersion` is a tentative cursor bookmark
  * `FromVersion` is a snapshot, and there exists a tentative cursor bookmark for that snapshot
  * `FromVersion` is a bookmark != tentative cursor bookmark, but there exists a tentative cursor bookmark for the same snapshot as the `FromVersion` bookmark

In those cases, the `check` concluded that we would delete `FromVersion`.
It came to that conclusion because the tentative cursor isn't part of `obsoleteAbs` if the protection strategy doesn't produce a tentative replication cursor.

The scenarios above can happen if the user changes the protection strategy from "with tentative cursor" to one "without tentative replication cursor", while there is a tentative replication cursor on disk.
The workaround was to rename the tentative cursor.

In all cases above, `TryBatchDestroy` would have destroyed the tentative cursor.

In case 1, that would fail the `Send` step and potentially break replication if the cursor is the last common bookmark. The `check` conclusion was correct.

In cases 2 and 3, deleting the tentative cursor would have been fine because `FromVersion` was a different entity than the tentative cursor. So, destroying the tentative cursor would be the right call.

The solution in this PR is as follows:
* add the `FromVersion` to the `liveAbs` set of live abstractions
* rewrite the `check` closure to use the full dataset path (`fullpath`) to identify the concrete ZFS object instead of the `zfs.FilesystemVersionEqualIdentity`, which is only identified by matching GUID.
  * Holds have no dataset path and are not the `FromVersion` in any case, so disregard them.

fixes #666
2023-07-04 20:21:48 +02:00
..
context.go [#307] add package trace, integrate it with logging, and adopt it throughout zrepl 2020-05-19 11:30:02 +02:00
endpoint_abstractions_cache.go Reformat all files with make format. 2020-08-31 23:57:45 +02:00
endpoint_guarantees.go fix handling of tenative cursor presence if protection strategy doesn't use it (#714) 2023-07-04 20:21:48 +02:00
endpoint_metrics.go replication + endpoint: replication guarantees: guarantee_{resumability,incremental,nothing} 2020-07-26 20:32:35 +02:00
endpoint_zfs_abstraction_last_received_hold.go Reformat all files with make format. 2020-08-31 23:57:45 +02:00
endpoint_zfs_abstraction_replication_cursor.go run go1.19 gofmt and make adjustments as needed 2022-10-24 22:22:41 +02:00
endpoint_zfs_abstraction_step_hold.go replication + endpoint: replication guarantees: guarantee_{resumability,incremental,nothing} 2020-07-26 20:32:35 +02:00
endpoint_zfs_abstraction_test.go zfs.NilBool: document its purpose and move it to its own package 'nodefault' 2021-02-20 17:04:57 +01:00
endpoint_zfs_abstraction.go fix handling of tenative cursor presence if protection strategy doesn't use it (#714) 2023-07-04 20:21:48 +02:00
endpoint_zfs_helpers_repr_test.go endpoint: refactor, fix stale holds on initial replication failure, zfs-abstractions subcmd, more efficient ZFS queries 2020-04-18 12:26:03 +02:00
endpoint_zfs_helpers_repr.go endpoint: refactor, fix stale holds on initial replication failure, zfs-abstractions subcmd, more efficient ZFS queries 2020-04-18 12:26:03 +02:00
endpoint_zfs_helpers_types.go endpoint: refactor, fix stale holds on initial replication failure, zfs-abstractions subcmd, more efficient ZFS queries 2020-04-18 12:26:03 +02:00
endpoint.go fix handling of tenative cursor presence if protection strategy doesn't use it (#714) 2023-07-04 20:21:48 +02:00
jobid.go replication + endpoint: replication guarantees: guarantee_{resumability,incremental,nothing} 2020-07-26 20:32:35 +02:00
placeholdercreationencryptionproperty_enumer.go fix encrypt-on-receive with placeholders 2021-12-18 15:12:47 +01:00
replicationguaranteekind_enumer.go replication + endpoint: replication guarantees: guarantee_{resumability,incremental,nothing} 2020-07-26 20:32:35 +02:00