symlinks in extended attributes

Corinna Vinschen corinna-cygwin@cygwin.com
Tue Jul 4 08:12:00 GMT 2006


In path.cc are two functions, get_symlink_ea and set_symlink_ea, which
are supposed to write and read symlink info to and from extended
attributes in a symlink file.  The functions are called in
symlink_worker resp. in symlink_info::check.

As it turns out now, I broke writing symlink info in EAs back in April
2004 (see the IMPLEMENT_STATUS_FLAG patch from 2004-04-13), and nobody
ever realized it!  This is obviously because the symlink info is still
available, just the additional info in the EA is missing.

I can fix this with a simple one-line patch, but I'm curious if this
doesn't rather mean we can drop this functionality entirely.

Every symlink reading requires some sort of CreateFile/ReadFile/
CloseHandle sequence anyway.  Given that the other two symlink readers,
symlink_info::check_shortcut and symlink_info::check_sysfile are pretty
streamlined, I'm wondering about the advantage of keeping the info
another time in the EAs.  Is it supposed to be faster?  I guess it's
faster now than before (using NtQueryEaFile instead of BackupRead), but
is it so much faster than symlink_info::check_shortcut/check_sysfile
that it's actually worth to keep another code path?


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Project Co-Leader          cygwin AT cygwin DOT com
Red Hat



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