From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Masover Subject: Re: reiser4 plugins Date: Fri, 01 Jul 2005 03:06:19 -0500 Message-ID: <42C4F97B.1080803@slaphack.com> References: <200506290509.j5T595I6010576@laptop11.inf.utfsm.cl> <87hdfgvqvl.fsf@evinrude.uhoreg.ca> <8783be6605062914341bcff7cb@mail.gmail.com> <878y0svj1h.fsf@evinrude.uhoreg.ca> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: list-help: list-unsubscribe: list-post: Errors-To: flx@namesys.com In-Reply-To: <878y0svj1h.fsf@evinrude.uhoreg.ca> List-Id: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: Hubert Chan Cc: Ross Biro , Horst von Brand , Kyle Moffett , Valdis.Kletnieks@vt.edu, Lincoln Dale , Gregory Maxwell , Hans Reiser , Jeff Garzik , Christoph Hellwig , Andrew Morton , linux-kernel@vger.kernel.org, ReiserFS List Hubert Chan wrote: > On Wed, 29 Jun 2005 17:34:41 -0400, Ross Biro said: > > >>I'm confused. Can someone on one of these lists enlighten me? > > >>How is directories as files logically any different than putting all >>data into .data files and making all files directories (yes you would >>need some sort of special handling for files that were really called >>.data). Then it's just a matter of deciding what happens when you >>call open and stat on one of these files? > > > Logically, I don't think there is a difference. A filesystem that > doesn't support file-as-dir could implement the same functionality that > way. [1] In fact, that's essentially what MacOS X/NeXTSTEP does with its > bundle format -- it's just a regular directory with regular files > inside. I, personally, would hate it if everything in my /bin suddenly became a directory, mainly because everything would stop working. Is that the kind of thing you're suggesting? I'm a little confused about the .data idea, I guess. >>But we could have a whole new set of system calls that treat things as >>magic, and if files as directories is as cool as many people think, >>apps will start using the new api. If not, they won't and the new api >>can be deprecated. > > > File-as-dir doesn't require new system calls (that I know of), which is > the whole point of the idea. Existing programs can edit the strange new > attributes without being modified. That is indeed the point, but scroll down. > The main thing blocking file-as-dir is that there are some > locking(IIRC?) issues. And, of course, some people wouldn't want it to > be merged into the mainline kernel. (Of course, the latter doesn't > prevent Namesys from maintaining their own patches for people to play > around with.) What's the locking issue? I think that was more about transactions... [...] > People like Horst (and probably others, who are less vocal), I think, > don't think that it's even worth trying it out because they don't see > any major advantages. Or at least they think that the potential > negatives outweigh the potential positives. I respect that they have > different opinions, but I of course disagree and attempt to convince > them otherwise. Did the /meta (metafs) idea get killed while I was out? Using that approach, your potential negatives are that apps which crawl the entire FS tree, starting at /, with hardcoded apps for /proc and /sys, are now broken -- but then, /sys already broke them once, so I don't particularly care if we break them again. Potential positives? I think even just because we like the idea is enough, because it doesn't break anything and doesn't really affect anyone who doesn't use it. Maybe there are coding standards, but I think others are working that out now.