Abstract: A file system independent virtualized boot block with discovery volume and cover files renders a volume visible when accessed by an accessing system which differs from a source system. For example, a downlevel operating system recognizes that data is present on a volume created in an uplevel operating system, even where the uplevel data itself may not be accessible.

Abstract: Method and system for establishing and maintaining quotas. An auto quota is defined and applied to a directory. Input and output is monitored to detect a successful operation that involves a subdirectory of the directory. A determination is made as to whether to apply a quota associated with the auto quota to the subdirectory. If the determination is that the quota is to be applied to the subdirectory, it is automatically applied.

Abstract: Method and system for maintaining namespace consistency between selected objects maintained by a file system and a filter associated therewith. Metadata regarding selected objects of a file system is maintained by a filter while the filter is attached to the file system and persisted in non-volatile storage. The namespace of the file system may be changed while the filter is unattached from the file system. Afterwards, when the filter is attached to the file system, the namespace of the filter is synchronized with the namespace of the file system for the selected objects.

Abstract: An extensible file system format for portable storage media is provided. The extensible file system format includes the specification of primary and secondary directory entry types that may be custom defined. The primary and secondary directory entry types can be further classified as critical and benign directory entries.

Abstract: Described is a mechanism comprising a data screening filter and user mode service that applies (enforces) policies regarding allowing or blocking file content of a directory, based on matching the filename against patterns associated with that directory. An administrator configures a screening policy, such as the types of files to allow in a particular directory and the types of files to block. File groups of member patterns and non-member exclusion patterns are defined and selectively collected in directory screening objects (DSOs). A directory screening object (DSO) is associated with a directory. When an I/O create request specifying a filename and a target directory is received, the filename is evaluated against the member/non-member patterns in the file groups referenced by the DSO for that directory to make for an allow or block policy decision. If not matched, DSOs on parent directories are evaluated upwards seeking a policy decision.

Abstract: Described is a mechanism comprising a data screening filter and user mode service that applies (enforces) policies regarding allowing or blocking file content of a directory, based on matching the filename against patterns associated with that directory. An administrator configures a screening policy, such as the types of files to allow in a particular directory and the types of files to block. File groups of member patterns and non-member exclusion patterns are defined and selectively collected in directory screening objects (DSOs). A directory screening object (DSO) is associated with a directory. When an I/O create request specifying a filename and a target directory is received, the filename is evaluated against the member/non-member patterns in the file groups referenced by the DSO for that directory to make for an allow or block policy decision. If not matched, DSOs on parent directories are evaluated upwards seeking a policy decision.

Abstract: File system methods and systems enabling efficient detection that a filename exists, by executing a hash function on the file name to reduce the overall computational complexity of determining that a directory entry might match the target filename, prior to performing the string comparison to determine the entry does match the target filename. A cross-device extensible means of providing a conversion function, such as uppercasing the filename, occurs prior to the hash. Methods of creating, deleting, and modifying the directory entries is further provided, as well as details of an embodiment of the file system described.

Abstract: Disclosed is a method for creating and reading a contiguous file in an extensible file system. During the creation of a file on the storage media, the file system format check the bitmap to determine if there are areas of free space on the media that would permit the storage of the file in a contiguous manner. By storing the file in a contiguous manner the file may later be read without resorting to the file allocation table, because the file itself would not be fragmented on the storage media. Once an area of free space has been identified, the file is written to the media in a contiguous manner. Further, an associated entry for the file in the directory entry is updated or created to indicate that the file is a contiguous file and also provides basic parameters necessary to read the file without resorting to accessing the file allocation table.

Abstract: File system metadata regarding states of a file system affected by transactions is tracked consistently even in the face of dirty shutdowns which might cause rollbacks in transactions which have already been reflected in the metadata. In order to only request time- and resource-heavy rebuilding of metadata for metadata which may have been affected by rollbacks, reliability information is tracked regarding metadata items. When a metadata item is affected by a transaction which may not complete properly in the case of a problematic shutdown or other event, that metadata item's reliability information indicates that it may not be reliable in case of such a problematic (“dirty” or “abnormal”) event. In addition to flag information indicating unreliability, timestamp information tracking a time of the command which has made a metadata item unreliable is also maintained.

Abstract: A method and system for maintaining namespace consistency between selected objects maintained by a file system and a filter associated therewith. A filter monitors selected types of requests (or operations associated therewith) and determines whether the object is within a namespace associated with the filter. The namespace associated with the filter is updated based on a change to the object.

Abstract: A recording method of the present invention includes the steps of: receiving a write instruction which specifies at least a logical sector in which data is to be written; determining whether the logical sector specified by the write instruction corresponds to a recorded physical sector or an unrecorded physical sector (S1111); when it is determined that the logical sector specified by the write instruction corresponds to an unrecorded physical sector, writing the data into the unrecorded physical sector (S1112); and when it is determined that the logical sector specified by the write instruction corresponds to a recorded physical sector, writing the data into an unrecorded physical sector other than the recorded physical sector (S1113), generating a remapping table including remapping information which remaps an original address of the recorded physical sector to a remapping address of the selected physical sector, and writing the remapping table on the write-once disc (S1114).

Abstract: A file system is enabled to use a Metadata Partition instead of VAT for write-once discs, and is provided by a pseudo-overwrite method with a plurality of tracks especially for metadata and file data. On applying this invention to a drive apparatus that supports pseudo-overwrite media, the file system distinguishes data to overwrite from data to append (S1701). When the data is newly written to a logical sector, the drive apparatus writes the data to a physical sector to which the logical sector corresponds (S1703). When the data being overwritten is data stored in the logical sector, the data is written to the other unrecorded physical sector in the volume space (S1704), and remapping information is written (S1705). The remapping information specifies the original address of the physical sector, and the remapping address of the physical sector in which the data is written.

Abstract: A method and system for computing disk space used by a directory and its descendants that may proceed while input and output are occurring that involve the directory and any of its descendants. A calculation of the total amount of disk space consumed by a set of objects is commenced. While performing the calculation, changes to the objects are monitored. If a change to one or more of the objects affects the disk space consumed by the objects, the calculation is changed so that the total reflects the change to the one or more objects.

Abstract: The recording method of the present invention includes the steps of: receiving a write instruction which specifies at least a logical sector in which data is to be written; determining whether the logical sector corresponds to a recorded physical sector or an unrecorded physical sector; when it is determined that the logical sector corresponds to an unrecorded physical sector, writing the data into the unrecorded physical sector, determining whether a verification of the data which has been written into a physical sector is successful, if the verification of the data that has been written is not successful, writing the data into an unrecorded physical sector, generating a remapping table including remapping information which remaps an original address of the physical sector corresponding to the logical sector to a remapping address of the selected physical sector, and writing the remapping table on the write-once disc.