Patent ID: 9727470
Date: 2017-08-08
CPC Classifications: G06F

Claim:
1. A method comprising: generating a cache tracking tree based on a stub file, wherein the cache tracking tree tracks file regions of the stub file, cached states associated with regions of the stub file, a set of cache flags, a version, a file size, a region size, a data offset, a last region, and a range map; associating the cache tracking tree with the stub file; receiving a read request associated with a set of regions of the stub file; activating a shared cache tracking tree lock on the cache tracking tree wherein the set of cache flags are set to indicate the shared cache tracking tree lock; activating a shared region lock for the set of regions, wherein the set of cache flags are set to indicate the shared region lock; determining a cached state associated with the set of regions of the stub file; in response to determining the cached state associated with the set of regions of the stub file do not have a state of not cached, upgrading the shared region lock to an exclusive region lock; reading file data from the set of regions; and deactivating the shared cache tracking tree lock and the exclusive region lock.