Re: [PATCH RFC] vfs: make fstatat retry on ESTALE errors fromgetattr call

From: Myklebust, Trond
Date: Tue Apr 17 2012 - 10:04:34 EST

On Tue, 2012-04-17 at 09:32 -0400, Jeff Layton wrote:
> On Tue, 17 Apr 2012 15:12:20 +0200
> Miklos Szeredi <miklos@xxxxxxxxxx> wrote:

> To do that would require protocol support that we simply don't have. We
> don't have a way to (for instance) say via NFS "give me the attributes
> for this filename". Well, at least not for NFSv3...

What's wrong with LOOKUP?

> With v4 you could theoretically construct a compound that does that,
> but you'd have to assume that the server won't release the reference to
> the inode midway through the compound. That's a reasonably safe
> assumption.

Actually, NFSv4 is the one that has the problem: there are no atomicity
guarantees within compounds, so you could theoretically get an ESTALE in
the GETATTR part of our lookup compound.

Trond Myklebust
Linux NFS client maintainer


èº{.nÇ+‰·Ÿ®‰­†+%ŠËlzwm…ébëæìr¸›zX§»®w¥Š{ayºÊÚë,j­¢f£¢·hš‹àz¹®w¥¢¸ ¢·¦j:+v‰¨ŠwèjØm¶Ÿÿ¾«‘êçzZ+ƒùšŽŠÝj"ú!¶iO•æ¬z·švØ^¶m§ÿðà nÆàþY&—