From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Masover Subject: Re: reiser4 plugins Date: Wed, 06 Jul 2005 15:47:37 -0500 Message-ID: <42CC4369.3070005@slaphack.com> References: <42CB1E12.2090005@namesys.com> <1740726161-BeMail@cr593174-a> <87hdf8zqca.fsf@evinrude.uhoreg.ca> <42CB7DE0.4050200@namesys.com> <42CBD7F6.2050203@slaphack.com> <42CC1DEE.7030502@namesys.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: list-help: list-unsubscribe: list-post: Errors-To: flx@namesys.com In-Reply-To: <42CC1DEE.7030502@namesys.com> List-Id: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: Hans Reiser Cc: Hubert Chan , "Alexander G. M. Smith" , ross.biro@gmail.com, vonbrand@inf.utfsm.cl, mrmacman_g4@mac.com, Valdis.Kletnieks@vt.edu, ltd@cisco.com, gmaxwell@gmail.com, jgarzik@pobox.com, hch@infradead.org, akpm@osdl.org, linux-kernel@vger.kernel.org, reiserfs-list@namesys.com, zam@namesys.com, vs@thebsh.namesys.com, ndiller@namesys.com, vitaly@thebsh.namesys.com Hans Reiser wrote: > David Masover wrote: > > >>And, once we start talking about applications, /meta will be more >>readily supported (as in, some apps will go through a pathname and >>stop when they get to a file, and then there's tar). On apps which >>don't have direct support for /meta, you'd be navigating to the file >>in question and then manually typing '...' into the dialog, so I don't >>see why typing '...' at the end is better than typing '/meta' or >>'/meta/vfs' at the beginning. > > > Performance. If you type it at the end, and you already have done the > lookup of the filename, then you can go from the file to one of its > methods, instead of a complete new traversal of another tree under /meta Only, it's a different view of the same tree. That may not matter performance-wise, though. Also, for performance-critical applications, the /meta tree is pretty easy -- it becomes more like /meta/inode/some_inode_number/. There's also the chroot issue, though. >>That said, I'm still not entirely sure how we get /meta/vfs to work >>other than adding a '...' sort of delimiter anyway. >> >> >>>>And a question: is it feasible to store, for each inode, its parent(s), >>>>instead of just the hard link count? >>>> >>>> >>> >>>Ooh, now that is an interesting old idea I haven't considered in 20 >>>years.... makes fsck more robust too.... >> >> >>Doesn't it make directory operations slower, too? > > > Not sure. It consumes space though. > > >>And, will it require a format change? >> > > Yes, but we have plugins now, so..... So, will the format change happen at mount time? Will it need a special mount flag? Will I need to use debugfs or some other offline tool?