Data recording/reproduction for write-once discs
View Patent ↗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 (S 1701 ). 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 (S 1703 ). 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 (S 1704 ), and remapping information is written (S 1705 ). 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.
1. A recording method for instructing a drive apparatus having a pseudo-overwrite function to write data on a write-once disc, the write-once disc including a volume space comprising a plurality of tracks, said pseudo-overwriting function allowing the drive apparatus to write data into an unrecorded area in response to an instruction to write said data into an already recorded area by replacement operation,
the recording method comprising the steps of:
(a) receiving a write request which specifies at least data for a file to be written;
(b) instructing the drive apparatus to read a file entry of a metadata file which contains metadata for managing the file from a location of the write-once disc, so as to obtain the file entry of the metadata file;
(c) obtaining track information indicating a location of each of the plurality of tracks;
(d) determining a track from the plurality of tracks in which metadata is to be written next, based on the file entry of the metadata file and the track information;
(e) instructing the drive apparatus to read the metadata from a location of the write-once disc, so as to obtain the metadata;
(f) obtaining a next writable address indicating a location at which data is to be written next within a track other than the track determined in the step (d), the track being selected from the plurality of tracks (S 1606 );
(g) updating the metadata to reflect the writing of the data specified by the write request;
(h) instructing the drive apparatus to write the data specified by the write request to a location indicated by the next writable address in the write-once disc; and
(i) instructing the drive apparatus to write at least a part of the updated metadata to the location from which the metadata is read in the step (e) in the write-once disc,
characterized by further comprising the steps of:
determining whether or not a next writable address within the track determined in the step (d) is valid;
when it is determined that the next writable address within the track determined in the step (d) is not valid, instructing the drive apparatus to allocate a first track in which metadata is to be written next and a second track in which data is to be written next, and updating the next writable address obtained in the step (f) to a next writable address within the second track;
determining whether or not the first track is allocated and at least the part of the updated metadata is written in the first track; and
when it is determined that the first track is allocated and at least the part of the updated metadata is written in the first track, updating the file entry of the metadata file to reflect the writing of at least the part of the updated metadata and instructing the drive apparatus to write the updated file entry of the metadata file at the location from which the file entry of the metadata file is read in step (b).
2. A system controller for instructing a drive apparatus having a pseudo-overwrite function to write data on a write-once disc, the write-once disc including a volume space comprising a plurality of tracks, said pseudo-overwriting function allowing the drive apparatus to write data into an unrecorded area in response to an instruction to write said data into an already recorded area by replacement operation,
the system controller comprising a controller for controlling the drive apparatus,
characterized in that the controller is configured to perform a process including the steps of the recording method according to claim 1 .
3. A system controller according to claim 2 , wherein the controller includes a semiconductor integrated circuit.
4. A non-transitory computer readable storage medium having stored thereon a program for use in a system controller for instructing a drive apparatus having a pseudo-overwrite function to write data on a write-once disc, the write-once disc including a volume space comprising a plurality of tracks, said pseudo-overwriting function allowing the drive apparatus to write data into an unrecorded area in response to an instruction to write said data into an already recorded area by replacement operation,
the program being characterized in that it is configured to perform a process including the steps of the recording method according to claim 1 .