Subject: Re: Relaxing NFS wcc checks
To: None <jmmv84@gmail.com>
From: YAMAMOTO Takashi <yamt@mwd.biglobe.ne.jp>
List: tech-kern
Date: 11/01/2006 08:30:01
> I found that wcc data
> is considered invalid if the real file's times are less or _equal_ to
> the cached file's times.

yes, detecting the condition is the purpose of the function.

> This causes problems when a file is
> accessed/created/whatever and the cached data is inserted on the exact
> same nanosecond in the wcc.

what problem are you talking about?
the message itself isn't a problem.  it means the client is trying
to avoid problems.

> The attached fix relaxes the condition checks to verifying if the
> cached data is strictly older than the real one.  Is it correct?

no, it isn't correct.

> Are
> there any invalid situations in which a real file's time is equal to
> the cached file's times and therefore wcc shall be disabled?

have you read the comment in the function?

> PS: BTW, what does wcc stand for?

weak cache consistency.

YAMAMOTO Takashi