markbase/docs/FUSE_PHASE2_STATUS.md

# MarkBase FUSE Phase 2 Implementation Status

## Current Status (2026-05-17)

### Completed

1. **FUSE-T Installation** ✅
   - Binary: `/Library/Application Support/fuse-t/bin/go-nfsv4-1.2.6` (20MB)
   - Backend support: nfs, fskit, smb
   - Installation verified via `sudo installer`

2. **FileSystem Trait Implementation** ✅
   - File: `src/fuse/markbase_fs.rs` (370 lines)
   - Implemented methods:
     - `init()` - Initialize filesystem
     - `lookup()` - Find file by name in parent directory
     - `getattr()` - Get file attributes (stat64)
     - `opendir()` - Open directory for reading
     - `readdir()` - List directory contents
     - `releasedir()` - Close directory
     - `open()` - Open file for reading
     - `read()` - Read file content (using ZeroCopyWriter)
     - `release()` - Close file
     - `statfs()` - Filesystem statistics

3. **SQLite Backend Integration** ✅
   - Database: `data/users/warren.sqlite` (12MB, 12659 nodes)
   - Tables used:
     - `file_nodes` - node_id, label, node_type, file_size, parent_id
     - `file_locations` - file_uuid, location
   - UUID-to-Inode mapping: First 8 bytes of UUID → u64 inode

4. **Compilation Success** ✅
   - 11 FUSE tests passed
   - Zero warnings in fuse module
   - Type conversions fixed (rusqlite::Error → io::Error)

### Next Steps (Phase 2)

#### Step 1: Real Mount Implementation

**Current Placeholder:**
```rust
pub fn mount(&self, mount_path: &Path) -> Result<()> {
    println!("=== Mounting MarkBase FUSE ===");
    println!("User: {}", self.user_id);
    println!("Database: {}", self.db_path.display());
    println!("Backend: {}", self.backend.name());
    println!("Mount path: {}", mount_path.display());
    
    Ok(())
}
```

**Required Implementation:**
```rust
use fuse_backend_rs::transport::{FuseSession, FuseChannel};
use fuse_backend_rs::api::server::Server;

pub fn mount(&self, mount_path: &Path) -> Result<()> {
    // 1. Create FUSE session
    let session = FuseSession::new(mount_path, "MarkBase", "", false)?;
    
    // 2. Mount filesystem
    session.mount()?;
    
    // 3. Create server with filesystem
    let server = Server::new(Arc::new(self.clone()));
    
    // 4. Spawn thread to handle requests
    thread::spawn(|| {
        let channel = session.new_channel()?;
        server.svc_loop(channel)?;
        Ok(())
    });
    
    Ok(())
}
```

#### Step 2: Backend Selection

**go-nfsv4 Binary Usage:**

```bash
# FSKit backend (macOS 26+, fastest)
/Library/Application Support/fuse-t/bin/go-nfsv4 \
  --backend fskit \
  --volname "MarkBase_warren" \
  --rwsize 65536 \
  --attrcache \
  --noatime

# NFSv4 backend (all macOS versions)
/Library/Application Support/fuse-t/bin/go-nfsv4 \
  --backend nfs \
  --listen_addr 127.0.0.1 \
  --volname "MarkBase_warren"
```

**Backend Auto-Selection Logic:**
- macOS 26+ → FSKit (direct path, ~650MB/s)
- macOS <26 → NFSv4 (TCP/IP, ~550MB/s)

#### Step 3: Warren User Test (12659 nodes)

**Test Plan:**
1. Mount warren filesystem:
   ```bash
   cargo run -- fuse --mount --user warren --dir /Volumes/MarkBase_warren
   ```

2. Verify mount:
   ```bash
   ls -la /Volumes/MarkBase_warren/
   ls -la /Volumes/MarkBase_warren/Home/
   ```

3. Count nodes:
   ```bash
   find /Volumes/MarkBase_warren -type f | wc -l   # Expected: 11857 files
   find /Volumes/MarkBase_warren -type d | wc -l   # Expected: 802 folders
   ```

4. Read test:
   ```bash
   cat /Volumes/MarkBase_warren/Home/.../test_file.txt
   ```

#### Step 4: Performance Validation

**AJA System Test (600MB/s target):**

1. Download AJA System Test:
   https://www.aja.com/en/products/aja-system-test

2. Install:
   ```bash
   hdiutil attach ~/Downloads/AJA_System_Test.dmg
   cp -R /Volumes/AJA\ System\ Test/*.app /Applications/
   hdiutil detach /Volumes/AJA\ System\ Test
   ```

3. Run 4K ProRes 4444 test:
   - Target: 600MB/s sustained write
   - Test file: `/Volumes/MarkBase_warren/test_4k_prores.mov`
   - Duration: 60 seconds

### Implementation Notes

**Challenges:**
1. **ZeroCopyWriter Integration** - read() method uses complex writer trait
   - Current implementation: `w.write_all(&buffer[..bytes_read])`
   - Optimization: Direct file copy to writer without intermediate buffer

2. **UUID Padding** - ino_to_uuid() truncates to 8 bytes
   - Issue: Full UUID is 32 chars, inode only stores 8 bytes
   - Solution: Use first 8 bytes for lookup, fallback to aliases_json

3. **Thread Safety** - MarkBaseFs needs Arc<Mutex> for concurrent access
   - Current: No locking (single-threaded placeholder)
   - Required: Arc<Mutex<MarkBaseFs>> for multi-threaded FUSE server

4. **Backend Binary Path** - go-nfsv4 is symlink
   - Actual: `/Library/Application Support/fuse-t/bin/go-nfsv4-1.2.6`
   - Symlink: `/Library/Application Support/fuse-t/bin/go-nfsv4`

**Key Learnings:**
- FUSE-T uses go-nfsv4 as unified binary (NFSv4/FSKit/SMB3)
- fuse-backend-rs provides FuseSession for mount management
- ZeroCopyWriter is required for read/write operations
- stat64 is libc::stat on macOS (not fuse_abi::stat64)

### Estimated Timeline

- **Day 1-2**: Mount implementation + backend integration
- **Day 3-4**: Warren user test + node verification
- **Day 5-7**: AJA System Test + performance optimization
- **Day 8-10**: Multi-user concurrent mount (10 users)
- **Day 11-12**: Final validation + documentation

---

**Last Updated:** 2026-05-17 11:00
**Phase:** 2 - Real Mount Implementation
**Status:** FileSystem trait ✅, Mount function ⏳