Re: [PATCH 08/31] nfsd41: sanity check client drc maxreqs

[Benny Halevy <bhalevy@panasas.com>]

On Apr. 28, 2009, 19:59 +0300, andros@netapp.com wrote:
> From: Andy Adamson <andros@netapp.com>
> 
> Ensure the client requested maximum requests are between 1 and
> NFSD_MAX_SLOTS_PER_SESSION
> 
> Signed-off-by: Andy Adamson <andros@netapp.com>
> ---
>  fs/nfsd/nfs4state.c |    5 +++++
>  1 files changed, 5 insertions(+), 0 deletions(-)
> 
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index e216169..59b601b 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -427,6 +427,11 @@ static int set_forechannel_maxreqs(struct nfsd4_channel_attrs *fchan)
>  {
>  	int status = 0, np = fchan->maxreqs * NFSD_PAGES_PER_SLOT;
>  
> +	if (fchan->maxreqs < 1)
> +		return nfserr_inval;

Is 0 prohibited by the protocol?
The server can set it to whatever value it wants,
or if we can live with it, it actually provides a
nice way to test the server end-cases.

Benny

> +	else if (fchan->maxreqs > NFSD_MAX_SLOTS_PER_SESSION)
> +		fchan->maxreqs = NFSD_MAX_SLOTS_PER_SESSION;
> +
>  	spin_lock(&nfsd_serv->sv_lock);
>  	if (np + nfsd_serv->sv_drc_pages_used > nfsd_serv->sv_drc_max_pages)
>  		np = nfsd_serv->sv_drc_max_pages - nfsd_serv->sv_drc_pages_used;