I wrote a test utility which opens a file on volume (), then dismounts FASTFAT volume using FSCTL_DISMOUNT_VOLUME, writes the file and closes the file.( intentionally not using FSCTL_LOCK_VOLUME, FSCTL_DISMOUNT_VOLUME and FSCTL_UNLOCK_VOLUME )
Write on the file failed with “device not ready error”. But close handle succeeded.
Does Dismount mark the handles invalid ? How the file system behaves in this case.