[tahoe-dev] [tahoe-lafs] #956: embed security metadata in parent directory

[tahoe-lafs]

#956: embed security metadata in parent directory
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 Reporter:  zooko                                                   |           Owner:           
     Type:  defect                                                  |          Status:  new      
 Priority:  major                                                   |       Milestone:  undecided
Component:  code-dirnodes                                           |         Version:  1.6.0    
 Keywords:  mutable newcaps newurls metadata forward-compatibility  |   Launchpad_bug:           
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Comment(by zooko):

 Replying to [comment:4 warner]:
 > Wouldn't a "last-known-version" update necessarily propagate all the way
 up to the rootcap?

 Yes, if a client feels compelled to update all parent dirs that it knows
 point to a node once it has learned about a new highest-known-version for
 the node. But it could instead opportunistically update parent nodes only
 when it was going to write to them anyway. This is a trade-off between
 safety and performance, and I was imagining a design at the better-
 performane end of the trade-off, requiring no extra writes to parent
 nodes. If we keep the highest-known-version info persistently in the
 client (per #955) then there would sometimes be useful highest-known-
 version information available locally when we are about to write to a
 dirnode for other reasons.

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Ticket URL: <http://allmydata.org/trac/tahoe/ticket/956#comment:5>
tahoe-lafs <http://allmydata.org>
secure decentralized file storage grid