This adds error returns to model methods called by the protocol layer.
Returning an error will cause the connection to be torn down as the
message couldn't be handled. Using this to signal that a folder isn't
currently available will then cause a reconnection a few moments later,
when it'll hopefully work better.
Tested manually by running with STRECHECKDBEVERY=0 on a nontrivially
sized setup. This panics reliably before this patch, but just causes a
disconnect/reconnect now.
As foretold by the prophecy, "once the database refactor is merged, then
shall appear a request to propagate errors from the store known
throughout the land as the NamedspacedKV, and it shall be good".
This PR does two things, because one lead to the other:
- Move the leveldb specific stuff into a small "backend" package that
defines a backend interface and the leveldb implementation. This allows,
potentially, in the future, switching the db implementation so another
KV store should we wish to do so.
- Add proper error handling all along the way. The db and backend
packages are now errcheck clean. However, I drew the line at modifying
the FileSet API in order to keep this manageable and not continue
refactoring all of the rest of Syncthing. As such, the FileSet methods
still panic on database errors, except for the "database is closed"
error which is instead handled by silently returning as quickly as
possible, with the assumption that we're anyway "on the way out".
* lib/versioner: Reduce surface area
This is a refactor while I was anyway rooting around in the versioner.
Instead of exporting every possible implementation and the factory and
letting the caller do whatever, this now encapsulates all that and
exposes a New() that takes a config.VersioningConfiguration.
Given that and that we don't know (from the outside) how a versioner
works or what state it keeps, we now just construct it once per folder
and keep it around. Previously it was recreated for each restore
request.
* unparam
* wip
Assume a folder error was set due to bad ignores on the latest scan.
Previously, doing a manual rescan would result in:
1. Clearing the folder error, which schedules (immediately) an fs
watcher restart
2. Attempting to load the ignores, which fails, so we set a folder
error and bail.
3. Now the fs watcher restarts, as scheduled, so we trigger a scan.
Goto 1.
This change fixes this by not clearing the error until the error is
actually cleared, that is, if both the health check and ignore loading
succeeds.
* lib/model: Don't panic on failed chmod-back on directory (fixes#5836)
This makes the "in writable dir"-wrapper log chmod-back errors instead
of panicking. To do that we need a logger so the function moved into the
model package which is also the only place it's used. The tests came
along.
(The test also exercised osutil.RenameOrCopy like some sort of
piggybacking. I removed that.)
