Re: [NFS] [PATCH] NFS server does not update mtime on setattr request

["J. Bruce Fields" <bfields@fieldses.org>]

On Wed, Jun 07, 2006 at 11:26:24AM -0400, Peter Staubach wrote:
> J. Bruce Fields wrote:
> >What's the basis for that interpretation?  The language seems extremely
> >clear:
> >
> >	"On successful completion, if the file size is changed, these
> >	functions will mark for update the st_ctime and st_mtime fields
> >	of the file, and if the file is a regular file, the S_ISUID and
> >	S_ISGID bits of the file mode may be cleared."
> >
> >Why are you concerned about this?  Do you have an actual application
> >that breaks?
> 
> Yes, there is a customer who is quite unhappy that the semantics over Linux
> client NFS are different than those of BSD, Solaris, and local file system
> access on Linux itself.  The basis for my work is based on a bugzilla from
> this customer.

OK; just out of curiosity, what's the url/bug number/whatever?

> My interpretation is based on looking at the local behavior on Linux, which
> changes mtime/ctime even if the file size does not change, and SunOS, which
> changes mtime/ctime even if the file size does not change and is very
> heavily SUSv3 compliant.

Fair enough.

> In this case, "changed" does not mean "made different".  It simply means
> that the file size is set to the new value.

That's ridiculous, though; that's just not what "changed" means, and
that renders the "if" clause redundant.  Better just to say "SUS is
wrong, and this is what everybody actually does...."

--b.