[Gnu-arch-users] FL-COW ...

[Davide Libenzi]

(... is not a Florida cow :)
The new version fixes the problem Andrea had on x32-64 in 64 bit mode and
handles home paths (~/).
It works fine here, used to replicate kernel source with cp -al and
working on it (diff+patch+emacs). Not tried with arch hardlinks but it
should not make any difference. To use it you setup the FLCOW_PATH
environment variable to list all paths where you want COW to take place
(using : separator) and you export your LD_PRELOAD to ($prefix)/lib/libflcow.so.
I set that up in my developer shells startup. The code is trivial,
basically if:

1) a file path begins with a path listed inside FLCOW_PATH
2) a file path is open with O_RDWR or O_WRONLY
3) S_ISREG(->st_mode) is true
4) ->st_nlink > 1

the hard link is broken by making a COW.


http://www.xmailserver.org/fl-cow-0.3.tar.gz



- Davide