Instead of using a separate .durable file to indicate
the durable status of a .data file, rename the .data
to include a durable marker in the filename. This saves
one inode for every EC fragment archive.
An EC policy PUT will, as before, first rename a temp
file to:
<timestamp>#<frag_index>.data
but now, when the object is committed, that file will be
renamed:
<timestamp>#<frag_index>#d.data
with the '#d' suffix marking the data file as durable.
Diskfile suffix hashing returns the same result when the
new durable-data filename or the legacy durable file is
found in an object directory. A fragment archive that has
been created on an upgraded object server will therefore
appear to be in the same state, as far as the consistency
engine is concerned, as the same fragment archive created
on an older object server.
Since legacy .durable files will still exist in deployed
clusters, many of the unit tests scenarios have been
duplicated for both new durable-data filenames and legacy
durable files.
Change-Id: I6f1f62d47be0b0ac7919888c77480a636f11f607
b13b49a27c