A transactional file system wherein multiple file system operations may be performed as a transaction. An application specifies that file system-related operations are to be handled as a transaction, and the application is given a file handle associated with a transaction context. For file system requests associated with a transaction context, a file system component manages the operations consistent with transactional behavior. The component provides data isolation by providing multiple versions of a file by tracking copies of changed pages, such that transactional readers do not receive changes to a file made by transactional writers, until the transactional writer commits the transaction and the reader reopens the file. The component handles namespace logging operations in a multiple-level log that facilitates logging and recovery. Page data is logged separate from the main log, with a unique signature that enables the log to determine whether a page was fully flushed to disk.