Re: HELP! vfs_readv() issue

From: Avishay Traeger
Date: Thu May 18 2006 - 14:05:18 EST


On Wed, 2006-05-17 at 17:44 -0400, Xin Zhao wrote:
> Thank you for your care. What I am trying to do is to rewrite NFS in
> the virtual machine environment so that network communication can be
> replaced with inter-VM communication.
>
> But after I remove the original rpc stuff, I ran into some strange
> problem, including this one. Interesting thing is that I noticed that
> even with standard NFS implementation, it is still possible that
> nfsd_read() return resp->count to be 0. At this time, eof is also
> equal to 1. This seems to be right since NFSD already reach the end of
> the file. But question is since 0 byte is read this time, NFS should
> detect EOF in previous read. Why need one more read?
>
> Xin

How are you reading the file? Some programs (I believe 'cat' is one of
them) will read a file until 0 is returned. Try writing a small C
program to read a file until EOF and see if the behavior changes.

Avishay Traeger
http://www.fsl.cs.sunysb.edu/~avishay/

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