From mboxrd@z Thu Jan  1 00:00:00 1970
From: Hans Reiser <reiser@namesys.com>
Subject: Re: reiser4 plugins
Date: Tue, 12 Jul 2005 18:20:25 -0700
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To: Neil Brown <neilb@cse.unsw.edu.au>
Cc: David Masover <ninja@slaphack.com>, Stefan Smietanowski <stesmi@stesmi.com>, Hubert Chan <hubert@uhoreg.ca>, Ross Biro <ross.biro@gmail.com>, Horst von Brand <vonbrand@inf.utfsm.cl>, Kyle Moffett <mrmacman_g4@mac.com>, Valdis.Kletnieks@vt.edu, Lincoln Dale <ltd@cisco.com>, Gregory Maxwell <gmaxwell@gmail.com>, Jeff Garzik <jgarzik@pobox.com>, Christoph Hellwig <hch@infradead.org>, Andrew Morton <akpm@osdl.org>, linux-kernel@vger.kernel.org, ReiserFS List <reiserfs-list@namesys.com>, Alexander Zarochentcev <zam@namesys.com>, vs <vs@thebsh.namesys.com>, Nate Diller <ndiller@namesys.com>, Vladimir Demidov <demidov@namesys.com>

Neil Brown wrote:

>On Tuesday July 12, reiser@namesys.com wrote:
>  
>
>>Neil Brown wrote:
>>
>>    
>>
>>>Maybe it is worth repeating Al Viro's suggestion at this point.  I
>>>don't have a reference but the idea was basically that if you open
>>>"/foo" and get filedescriptor N, then
>>>  /proc/self/fds/N-meta
>>>is a directory which contains all the meta stuff for "/foo".
>>>Then it is trivial to get the 'meta' stuff given a filedescriptor and
>>>if you have a pathname, you can always get yourself a filedescriptor.
>>> 
>>>
>>>      
>>>
>>This sound like it might be cute, but filedescriptors are too heavy
>>weight for stat data accesses in quantity.
>>
>>In general, the whole file handle paradigm is too heavy for lightweight
>>files.
>>    
>>
>
>That may well be true, but is completely orthogonal to filesystem name
>semantics. 
>
>If you find file descriptors too slow, come up with an alternate (I
>suspect you have in the reiser4 syscall, but I haven't looked at
>that yet), implement it in the VFS, and show the world benchmarks of
>real-world applications that go faster with this new interface.
>
>I doubt that you would then have a great deal of trouble in getting
>the interface accepted (some trouble of course as you will need to
>convince a few people, but numbers speak quite loudly).
>
>I suspect that there might need to be a new internal interface into
>filesystems, and filesystems which don't provide that will not get the
>same speed benefit, but that is perfectly acceptable.
>
>NeilBrown
>
>
>  
>
We need time, and then we can demonstrate sys_reiser4, it is not ready
for showing yet.....

Hans