Benefits are significant speed improvements on node creation/insertion while
keeping the lookup times low and still allowing sequential iteration over the
nodes.
of free blocks on the device and when free blocks are getting tight it tries
to readjust/recalculate that value by syncing the FS.
Second stage will be resizing the data/metadata partitions.
allow CD-ROM/DVD-ROM/DB-ROM drives to read the media while still allowing them
to be appended later. It can also be seen as a way to make mountable
snapshots.
old somewhat naive selection scheme that didn't allow different allocation
settings for nodes, directory information (FIDs) and data.
Also fix some curious side-effects of atime updates on RMW devices.
preliminary Metadata partition write support but its disabled still since
its not finished yet and not functioning correctly. All other formats are
checked and should work fine.
improvements of at least 4 times in untarring and roughly 100 to 500 times
on file creation in big directories. Lookup of files was O(n*n) and is now
O(1) even for file creation. Free spaces in the directory are kept in a
seperate list for fast file creation.
The postmark benchmark gives:
UDF old:
pm>set transactions 2000
pm>set number 3000
pm>run
Creating files...Done
Performing transactions..........Done
Deleting files...Done
Time:
1593 seconds total
681 seconds of transactions (2 per second)
Files:
3956 created (2 per second)
Creation alone: 3000 files (4 per second)
Mixed with transactions: 956 files (1 per second)
990 read (1 per second)
1010 appended (1 per second)
3956 deleted (2 per second)
Deletion alone: 2912 files (9 per second)
Mixed with transactions: 1044 files (1 per second)
Data:
5.26 megabytes read (3.38 kilobytes per second)
21.93 megabytes written (14.10 kilobytes per second)
pm>
UDF new:
pm>set transactions 2000
pm>set number 3000
pm>run
Creating files...Done
Performing transactions..........Done
Deleting files...Done
Time:
19 seconds total
3 seconds of transactions (666 per second)
Files:
3956 created (208 per second)
Creation alone: 3000 files (230 per second)
Mixed with transactions: 956 files (318 per second)
990 read (330 per second)
1010 appended (336 per second)
3956 deleted (208 per second)
Deletion alone: 2912 files (970 per second)
Mixed with transactions: 1044 files (348 per second)
Data:
5.26 megabytes read (283.66 kilobytes per second)
21.93 megabytes written (1.15 megabytes per second)
heavily fragmented files.
Also fixing some (rare) allocation bugs and function name streamlining.
Tested on harddisc, CD-RW and CD-R i.e. all three basic backend classes.
and DVD's behave like floppy discs. Writing is supported upto and including
version 2.01; version 2.50 and 2.60 will follow.
Also extending the UDF implementation to support symbolic links and
hardlinks.
Added are the mmcformat(8) tool to format rewritable CD/DVD discs and
newfs_udf(8).
Limitations:
all operations can be performed on the file system though the
sheduling is currently optimised for archiving workloads.
mv(1)/rename(2) is currently only implemented for non-directories.
The code supports read access to all media types that CD/DVD type drives
can recognize including DVD-RAM and BD- drives as well as harddisc partions
and vnd devices. UDF versions upto the latest 2.60 are to be supported
though due to lack of test media version 2.50 and 2.60 are not implemented
yet though easy to add. Both open and closed media are supported.
Write access is planned and in preparation. To facilitate this some hooks
are present in the code that are not strictly needed in a read-only
implementation but which allow writing to be added more easily.
Implemented and tested media types are CD-ROM, CD-R, CD-RW, CD-MRW,
DVD-ROM, DVD*R, DVD*RW, DVD+MRW but the same code can also read DVD-RAM,
HD-DVD and BluRay discs. Also vnd devices have been tested with several
sector sizes.
Discs created and written by UDFclient, Nero's InCD and Roxio's
DirectCD/Drag2Disc read fine.
