Whiteout support for tmpfs [Was: unionfs a little improvement]

Ed Schouten ed at 80386.nl
Fri Aug 20 17:03:30 UTC 2010


Hi all,

Even though the proposed fix for unionfs would still be nice to have in
SVN, I just wrote a patch for tmpfs to add support for whiteouts:

	http://80386.nl/pub/tmpfs-whiteout.txt

Basically I've implemented it by allowing directory entries to refer to
NULL inodes, to indicate the entry is a whiteout. I think the patch
should work pretty well, but what I dislike about it, is that when it
removes a file and replaces it by a whiteout, it deallocates the entire
directory entry, followed by the allocation of a new directory entry for
the whiteout. This could be done more efficiently, but the problem is
that it turns the code into a mess.

Any comments?

-- 
 Ed Schouten <ed at 80386.nl>
 WWW: http://80386.nl/
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