In principle, the JSON format of Tree objects is extensible without
requiring a format change. In order to not loose information just play
it safe and reject rewriting trees for which we could loose data.
The lock test creates a lock and checks that it is not stale. However,
it is possible that the lock is refreshed concurrently, which updates
the lock timestamp. Checking the timestamp in `Stale()` without
synchronization results in a data race. Thus add a lock to prevent
concurrent accesses.
The lock test creates a lock and checks that it is not stale. This also
tests whether the corresponding process still exists. However, it is
possible that the lock is refreshed concurrently, which updates the lock
timestamp. Calling `processExists()` with a value receiver, however,
creates an unsynchronized copy of this field. Thus call the method using
a pointer receiver.
The test did not wait for the mount command to fully shutdown all
running goroutines. This caused the go race detector to report a data
race related to lock refreshes.
==================
WARNING: DATA RACE
Write at 0x0000021bdfdb by goroutine 667:
github.com/restic/restic/internal/backend/retry.TestFastRetries()
/restic/restic/internal/backend/retry/testing.go:7 +0x18f
github.com/restic/restic/cmd/restic.withTestEnvironment()
/restic/restic/cmd/restic/integration_helpers_test.go:175 +0x183
github.com/restic/restic/cmd/restic.TestMountSameTimestamps()
/restic/restic/cmd/restic/integration_fuse_test.go:202 +0xac
testing.tRunner()
/usr/lib/go/src/testing/testing.go:1446 +0x216
testing.(*T).Run.func1()
/usr/lib/go/src/testing/testing.go:1493 +0x47
Previous read at 0x0000021bdfdb by goroutine 609:
github.com/restic/restic/internal/backend/retry.(*Backend).retry()
/restic/restic/internal/backend/retry/backend_retry.go:72 +0x9e
github.com/restic/restic/internal/backend/retry.(*Backend).Remove()
/restic/restic/internal/backend/retry/backend_retry.go:149 +0x17d
github.com/restic/restic/internal/cache.(*Backend).Remove()
/restic/restic/internal/cache/backend.go:38 +0x11d
github.com/restic/restic/internal/restic.(*Lock).Unlock()
/restic/restic/internal/restic/lock.go:190 +0x249
github.com/restic/restic/cmd/restic.refreshLocks.func1()
/restic/restic/cmd/restic/lock.go:86 +0xae
runtime.deferreturn()
/usr/lib/go/src/runtime/panic.go:476 +0x32
github.com/restic/restic/cmd/restic.lockRepository.func2()
/restic/restic/cmd/restic/lock.go:61 +0x71
[...]
Goroutine 609 (finished) created at:
github.com/restic/restic/cmd/restic.lockRepository()
/restic/restic/cmd/restic/lock.go:61 +0x488
github.com/restic/restic/cmd/restic.lockRepo()
/restic/restic/cmd/restic/lock.go:25 +0x219
github.com/restic/restic/cmd/restic.runMount()
/restic/restic/cmd/restic/cmd_mount.go:126 +0x1f8
github.com/restic/restic/cmd/restic.testRunMount()
/restic/restic/cmd/restic/integration_fuse_test.go:61 +0x1ce
github.com/restic/restic/cmd/restic.checkSnapshots.func1()
/restic/restic/cmd/restic/integration_fuse_test.go:90 +0x124
==================
In some rare cases files could be created which contain null IDs (all
zero) in their content list. This was caused by a race condition between
growing the `Content` slice and inserting the blob IDs into it. In some
cases the blob ID was written to the old slice, which a short time
afterwards was replaced with a larger copy, that did not yet contain the
blob ID.
We previously checked whether the set of snapshots might have changed
based only on their number, which fails when as many snapshots are
forgotten as are added. Check for the SHA-256 of their id's instead.
