Method For Implementing Persistent File Pre-Allocation

A computer system comprising:

• a file system to log metadata;
• a first i-node in the file system to manage file operations, said first i-node having initialized blocks;
• a second i-node in the file system for a given file, said second i-node having pre-allocated non-initialized blocks;
• an allocation manager in the file system to establish an association of the first i-node with second i-node;
• and
• said allocation manager to direct transfer of blocks from said second i-node to said first i-node in response to a requirement for non-initialized blocks in a pre-allocated range of blocks present on said second i-node in a write operation.

An article comprising:

• a tangible computer readable carrier including computer program instructions configured to pre-allocate data blocks in conjunction with a first i-node to manage file operations and a second i-node having pre-allocated non-initialized blocks, comprising;
• instructions to associate said first i-node with said second i-node through a mapping technique;
• and
• instructions to transfer corresponding blocks from said second i-node to said first i-node in response to a write operation requiring non-initialized blocks in a pre-allocated range of blocks absent from said first i-node.

A method for persistent pre-allocation of data blocks comprising:

• maintaining a primary i-node to manage file operations, said primary i-node having a contiguous set of mapped data blocks;
• backing said primary i-node with a first level secondary i-node for mapping initialized data blocks in a pre-allocated range;
• backing said first level secondary i-node with a second level secondary i-node for mapping pre-allocated non-initialized data blocks;
• associating said primary i-node with said first level secondary i-node, and associated said first level secondary i-node with said second level secondary i-node through a mapping technique;
• and
• transferring corresponding data blocks from said second level secondary i-node to said first level secondary i-node, and transferring a contiguous set of initialized pre-allocated data blocks from said first level secondary i-node to said primary i-node responsive to a write operation.