81a56777df
The slow-filesystem warning fired for any model path under /mnt/, which false-positives on native-Linux mounts (ZFS/ext4/xfs/NFS) that commonly live there. Check the actual filesystem type via statfs() against the 9p superblock magic (0x01021997) instead, so it only warns for a genuine WSL 9p mount. Linux-only (statfs); no behavior change on other platforms.