Messages in this thread |  | | Date | Wed, 06 Jul 2005 08:09:10 -0500 | From | David Masover <> | Subject | Re: reiser4 plugins |
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Hans Reiser wrote: > Hubert Chan wrote: > > >>On Tue, 05 Jul 2005 20:50:08 -0400 EDT, "Alexander G. M. Smith" <agmsmith@rogers.com> said: >> >> >> >> >>>That sounds equivalent to no hard links (other than the usual parent >>>directory one). If there's any directory with two links to it, then >>>there will be a cycle somewhere! >>> >>> >> >>What we want is no directed cycles. That is A is the parent of B is the >>parent of C is the parent of A. We don't care about A is the parent of >>B is the parent of C; A is the parent of B is the parent of C. >> >>OK, here's a random idea that just popped into my head, and to which >>I've given little thought (read: none whatsoever), and may be the >>stupidest idea ever proposed on LKML, but thought I would just toss it >>out to see if it could stimulate someone to come up with something >>better (read: sane): Conceptually, foo/.... is just a symlink to >>/meta/[filesystem]/[inode of foo]. >> >> > > Except that we want the metafiles to go away when the base file goes away.
Only, /meta is a filesystem that already makes stuff go away for us, so all we have left is the issue of whether using /meta costs us performance, or whether breaking POSIX to add a symlink (such as foo/...) really gives us that much more usability.
I don't know the first thing about whether it costs us performance, although it seems like it could be negligable considering the existance of mount --bind.
I don't think file-as-dir gives us that much more usability, because we can always create a simple program or shell script that 'cd's us into metadata. It's still easier than having a simple program that manipulates the metadata directly, because this way we can do 'cd' and 'ls' and so on inside the metadata directory.
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.
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?
And, will it require a format change? - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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