Patent ID: 7636946

Claim:
A computer storage medium having computer-executable instructions for executing in an environment supporting file system transactions, comprising: detecting that a file is participating within transaction, wherein the transaction is atomic, consistent, and isolated; upon detecting that the file is participating within the transaction, searching a cache for a cache entry that has a transaction context that is equivalent to the transaction context of the file wherein the cache entry indicates that the file was previously scanned for unwanted modifications; upon locating a cache entry having an equivalent transaction context, accessing a time stamp and metadata within the cache entry, wherein the time stamp indicates when the last scan of the file occurred, and wherein the metadata indicates when the file was last modified; determining from the time stamp and the metadata of the cache entry that the file was modified by the transaction subsequent to the last scan; upon determining that the file was modified subsequent to the last scan, scanning the modified file within the transaction to detect whether the file contains an unwanted modification that was made within the transaction to the file; and upon detecting that the file contains no unwanted modification, modifying the cache entry to indicate that the file contains no unwanted modification such that a subsequent request to open the file may be performed without scanning the file for unwanted modifications.