Runtime filesystem consistency checking [LWN.net]

Runtime filesystem consistency checking

Posted Apr 3, 2012 19:58 UTC (Tue) by NAR (subscriber, #1313)
In reply to: Runtime filesystem consistency checking by nybble41
Parent article: Runtime filesystem consistency checking

This also seems to introduce a second point of failure

This was my first thought too. They are using code to check code, which is kind of like automated tests. In my experience tests are wrong about as many times as the code itself (but this could be due to our fragile test environment), so it's one more thing to get right. On the other hand if Recon is changed a lot fewer times than the filesystem code itself, then Recon can reach sufficient maturity to be actually useful.

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Runtime filesystem consistency checking

Posted Apr 3, 2012 23:28 UTC (Tue) by neilbrown (subscriber, #359) [Link]

It reminds me a lot of lockdep.

lockdep is brilliant for developers as it warns you early of your bugs, just as this 'recon' would warn ext3 developers of their bugs.
But lockdep used to report lots of false positives - this has got a lot better over the years though.

I'm not sure I'd enable lockdep or recon in production though. There is a real cost, and it is not at all likely to help more than it hurts.

Runtime filesystem consistency checking

Posted Apr 4, 2012 13:10 UTC (Wed) by ashvin (guest, #83894) [Link]

We expect that Recon will initially be used mainly for development. As it matures, it could be deployed in production use. The need to change it over time should be comparable to the need to change fsck.