On December 9, 2004 [sic], Sergey Reva wrote: > term%: pwd > term%: /n/dump/2004/xxxx > term%: lc > xxxxxxxxxxxxxx > xxxxxxxxxxxxxx > xxxxxxxxxxxxxx > term%: unmount /n/dump # how I can do this? > # I mean, Linux in this case > # say: ... busy ...
Linux is broken. Not being able to unmount a file system (thus stopping people from accessing it in the future) shouldn't be held up by one or two processes that have open files on that file system. It's not hard to get the reference counts right, and Plan 9 does. The 9P connection corresponding to /n/dump won't be dropped until all the references go away, but it can be removed from the name space at any time. > term%: cd .. > # now I in /n/dump/2004 > term%: cd .. > # now I in /n/dump > term%: cd .. > # now I in /n > term%: lc # but, what I see? > active archive snapshot > term%: # now I can browse all subfolders Plan 9 is broken too. The implementation of dotdot consults the name space to answer the question "I just walked ..; what directory am I in?", but you removed the necessary entry from the name space! This is a nice example why the dotdot algorithm isn't quite right. (I have previously posted much more complicated and less understandable examples of the same.) Thanks. I missed this email the first time it went by (I was out of town and only skimming mail), but it was a joy to discover, even nine months late. There is a new dotdot algorithm in the works. Russ
