* fix(admin): release mutex before disk I/O in maintenance queue
saveTaskState performs synchronous BoltDB writes. Calling it while
holding mq.mutex.Lock() in AddTask, GetNextTask, and CompleteTask
blocks all readers (GetTasks via RLock) for the full disk write
duration on every task state change.
During a maintenance scan AddTasksFromResults calls AddTask for every
volume — potentially hundreds of times — meaning the write lock is
held almost continuously. The HTTP handler for /maintenance calls
GetTasks which blocks on RLock, exceeding the 30s timeout and
returning 408 to the browser.
Fix: update in-memory state (mq.tasks, mq.pendingTasks) under the
lock as before, then unlock before calling saveTaskState. In-memory
state is the authoritative source; persistence is crash-recovery only
and does not require lock protection during the write.
* fix(admin): add mutex to ConfigPersistence to synchronize tasks/ filesystem ops
saveTaskState is now called outside mq.mutex, meaning SaveTaskState,
LoadAllTaskStates, DeleteTaskState, and CleanupCompletedTasks can be
invoked concurrently from multiple goroutines. ConfigPersistence had no
internal synchronization, creating races on the tasks/ directory:
- concurrent os.WriteFile + os.ReadFile on the same .pb file could
yield a partial read and unmarshal error
- LoadAllTaskStates (ReadDir + per-file ReadFile) could see a
directory entry for a file being written or deleted concurrently
- CleanupCompletedTasks (LoadAllTaskStates + DeleteTaskState) could
race with SaveTaskState on the same file
Fix: add tasksMu sync.Mutex to ConfigPersistence, acquired at the top
of SaveTaskState, LoadTaskState, LoadAllTaskStates, DeleteTaskState,
and CleanupCompletedTasks. Extract private Locked helpers so that
CleanupCompletedTasks (which holds tasksMu) can call them internally
without deadlocking.
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Co-authored-by: Anton Ustyugov <anton@devops>
Anton
b4c7d42a06