Re: Cache invalidation bug in NFS v3 - trivially reproducible

From: Trond Myklebust
Date: Tue Oct 11 2005 - 09:48:33 EST

ty den 11.10.2005 Klokka 11:09 (+0200) skreiv Leif Nixon:
> Hi,
> We have come across a bug where a NFS v3 client fails to invalidate
> its data cache for a file even though it realizes that the file
> attributes have changed. We have been able to recreate the bug on a
> range of kernel versions and different underlying file systems.
> Here's a minimal way to reproduce the error (there seems to be some
> timing issues involved, but this has worked at least 90% of the time):
> NFS client n1 NFS client n2
> $ echo 1 > f
> $ cat f
> 1
> $ touch .
> $ echo 2 > f
> $ touch f
> $ cat f
> 1
> Now client n2 is stuck in a state where it uses its old cached data
> forever (or at least for several hours):

Yep. I can see a problem whereby the cache is "losing" consistency
information when you do this sort of thing. I'm working on a fix.


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at