Re: [PATCH net-next 8/8] SUNRPC: use min() to simplify the code

[Trond Myklebust <trondmy@hammerspace.com>]

On Sat, 2024-08-24 at 14:21 -0400, Chuck Lever wrote:
> On Sat, Aug 24, 2024 at 07:07:50PM +0100, Simon Horman wrote:
> > On Thu, Aug 22, 2024 at 09:39:08PM +0800, Li Zetao wrote:
> > > When reading pages in xdr_read_pages, the number of XDR encoded
> > > bytes
> > > should be less than the len of aligned pages, so using min() here
> > > is
> > > very semantic.
> > > 
> > > Signed-off-by: Li Zetao <lizetao1@huawei.com>
> > > ---
> > >  net/sunrpc/xdr.c | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > 
> > > diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c
> > > index 62e07c330a66..6746e920dbbb 100644
> > > --- a/net/sunrpc/xdr.c
> > > +++ b/net/sunrpc/xdr.c
> > > @@ -1602,7 +1602,7 @@ unsigned int xdr_read_pages(struct
> > > xdr_stream *xdr, unsigned int len)
> > >  	end = xdr_stream_remaining(xdr) - pglen;
> > >  
> > >  	xdr_set_tail_base(xdr, base, end);
> > > -	return len <= pglen ? len : pglen;
> > > +	return min(len, pglen);
> > 
> > Both len and pglen are unsigned int, so this seems correct to me.
> > 
> > And the code being replaced does appear to be a min() operation in
> > both form and function.
> > 
> > Reviewed-by: Simon Horman <horms@kernel.org>
> > 
> > However, I don't believe SUNRPC changes usually don't go through
> > next-next.
> > So I think this either needs to be reposted or get some acks from
> > Chuck Lever (already CCed).
> > 
> > Chuck, perhaps you can offer some guidance here?
> > 
> > >  }
> > >  EXPORT_SYMBOL_GPL(xdr_read_pages);
> > >  
> > > -- 
> > > 2.34.1
> > > 
> > > 
> 
> Changes to net/sunrpc/ can go through Anna and Trond's NFS client
> trees, through the NFSD tree, or via netdev, but they are typically
> taken through the NFS-related trees.
> 
> Unless the submitter or the relevant maintainers prefer otherwise,
> I don't see a problem with this one going through netdev. Let me
> know otherwise.
> 
> Acked-by: Chuck Lever <chuck.lever@oracle.com>
> 
> 

What is the value of this change? Unless the current code is actually
broken or somehow difficult to read, then I much prefer to leave it
untouched so that any future back ports of fixes to code around that
line remain trivial.

So NACK to this change for now.

-- 
Trond Myklebust
Linux NFS client maintainer, Hammerspace
trond.myklebust@hammerspace.com