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.
it could result in theory result in descriptor trashing.
On the performance side, it would try to fixup *every* descriptor even if
it wasn't an internally allocated one. Performance loss wasn't that big but
every bit helps.
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)
unlock the source directory again on exit. The stub that doesn't allow
cross directory renames for now jumped to the wrong exit point and thus
left a locked directory node that paniced on next locking.
