US Patent 10146782 Secure erasure of files by a filesystem

In one embodiment, a method is performed by a computing device configured to manage a filesystem stored on persistent storage. The method includes (a) receiving a command to delete a range of a file of the filesystem, (b) removing blocks of the range from being accessible to the filesystem as part of the file, (c) overwriting a block of the range using a secure erasure technique, and (d) subsequent to overwriting the block, freeing the block for re-use by the filesystem. A data storage system, apparatus, and computer program product for performing a similar method are also provided.