Patent ID: 6571259
Filing Date: 2003-05-27
Classification: G06F,Y10S

Abstract:
A method of operating a file server having a file system cache memory and storage, a file system being stored in the storage, said method comprising:(a) the file server receiving at least one write request from at least one client, and in response, writing new file system attributes and new file system data to the file system cache memory, the new file system attributes including new links between file system objects and file system blocks, (b) the-file server receiving a commit request from the client, the new file system attributes and the new file system data not being written into the file system in storage until receipt of the commit request, and in response to the commit request, writing the new file system attributes and the new file system data to the file system in storage; wherein the file server maintains in memory a directory and file mapping data structure for the file system, the directory and file mapping data structure permitting file system block allocations and linkages between file system objects and the file system blocks to change during read/write access to the file system by the client prior to receiving the commit request, the file system block allocations including allocated blocks having block allocations that are the same as block allocations in the file system as stored in the storage, and preallocated blocks having block allocations that are different from block allocations in the file system as stored in the storage, the preallocated blocks storing new file system data for changes to be made to the on-disk file system and not yet committed to the on-disk file system, and the directory and file mapping data structure identifying the allocated blocks and the preallocated blocks and distinguishing the preallocated blocks from the allocated blocks.