From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans Reiser Subject: Re: File as a directory - VFS Changes Date: Mon, 06 Jun 2005 22:08:54 -0700 Message-ID: <42A52BE6.3000403@namesys.com> References: <17050.62052.318426.711322@gargle.gargle.HOWL> <429C7D0A.6040200@namesys.com> <200505311630.j4VGUeIt007432@turing-police.cc.vt.edu> <1117558515.13252.21.camel@localhost> <429C97F9.8000009@namesys.com> <1117559594.13252.26.camel@localhost> <429CAC86.3080308@namesys.com> <1117573285.13252.63.camel@localhost> <1117573714.13252.69.camel@localhost> <17052.59096.785042.935234@gargle.gargle.HOWL> <1117580508.25017.21.camel@localhost> <17053.36948.892227.432434@gargle.gargle.HOWL> <17053.37172.885941.857716@gargle.gargle.HOWL> <1117634812.26560.33.camel@titania.zlynx.org> <17053.51551.825703.450388@gargle.gargle.HOWL> <1117640452.12866.9.camel@localhost> <17053.61465.359382.791640@gargle.gargle.HOWL> <1117652606.28827.7.camel@localhost> <17054.57795.295945.256623@gargle.gargle.HOWL> <1117737334.9224.51.camel@localhost> <17055.39986.10130.284697@gargle.gargle.HOWL> <42A099F6.20208@nam Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: list-help: list-unsubscribe: list-post: Errors-To: flx@namesys.com In-Reply-To: <17058.1217.672209.187032@gargle.gargle.HOWL> List-Id: Content-Type: text/plain; charset="us-ascii" To: Nikita Danilov Cc: Jonathan Briggs , Valdis.Kletnieks@vt.edu, "Alexander G. M. Smith" , leocomerford@gmail.com, reiserfs-list@namesys.com, ninja@slaphack.com, Nate Diller Nikita Danilov wrote: >Hans Reiser writes: > > Nikita Danilov wrote: > > > > > > > >But cycles are "solvable" in current file systems too: they simply do > > >not exist there. > > > > > > > > Yes, but Nikita, cycles represent semantic functionality that has value > > because being able to embody more expressions means more power of > >If you mean that multiple parents have some value, I agree. Problem is >that solutions proposed so far have severe limitation: > > - they add support for cycle detection that is necessary to support > multiple parents, but that support is only efficient for "small" > datasets: when total number of objects is not very big, and "average" > object has only one parent. > > - even when there are no multiple parents, system is not efficient for > large number of files. > > Can you say this in more detail? > > expression. If some way can be found to allow them, then functionality > > is increased. Separating links that increase reference count from links > > that merely point (ala hard vs. sym links) is one approach. If there > > was effective enough for real world use cycle detection, that would be > > better. > >It seems to me that in the domains where proposed designs are >applicable, symlinks already provide viable solution. > > I have been thinking that disabling hard links for filedirectories might be an acceptable solution for reiser4 if cycles are a deeper problem than I currently appreciate. We can then allow people to turn off one of either filedirectories or hard links. I would prefer solving the cycles problem though.... >Nikita. > > > >