* Add TraverseBfsWithContext and fix race conditions in error handling
- Add TraverseBfsWithContext function to support context cancellation
- Fix race condition in doTraverseBfsAndSaving using atomic.Bool and sync.Once
- Improve error handling with fail-fast behavior and proper error propagation
- Update command_volume_fsck to use error-returning saveFn callback
- Enhance error messages in readFilerFileIdFile with detailed context
* refactoring
* fix error format
* atomic
* filer_pb: make enqueue return void
* shell: simplify fs.meta.save error handling
* filer_pb: handle enqueue return value
* Revert "atomic"
This reverts commit 712648bc35.
* shell: refine fs.meta.save logic
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Co-authored-by: Chris Lu <chris.lu@gmail.com>
- Modified `needle_map_memory.go` to include needles with size=0 during needle map loading
- Updated `volume_write.go` to handle size=0 needles in delete operations
