Re: [PATCH] nfsd41: compare request's opcnt with session's maxops at nfsd4_sequence

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

On Wed, Apr 27, 2011 at 09:09:58AM +0800, Mi Jinlong wrote:
> Make sure nfs server can distinguish request contains more ops
> than channel allowed.

Yes, sequence looks like a reasonable op to catch this error.  The spec
doesn't care as far as I can tell (and it's a buggy-client case, so why
should it), and we already check that any compound not starting with a
sequence has only one op.

> Signed-off-by: Mi Jinlong <mijinlong@cn.fujitsu.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 fbde6f7..4f9fc68 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -1749,6 +1749,11 @@ nfsd4_sequence(struct svc_rqst *rqstp,
>  	if (!session)
>  		goto out;
>  
> +	status = nfserr_too_many_ops;
> +	if (((struct nfsd4_compoundargs *)rqstp->rq_argp)->opcnt >

Kind of a cumbersome construction, though.

Eh, maybe overkill, but how about this?:

--b.

commit d5eee1629fb9d3a55e5793d156026248c14cb46c
Author: Mi Jinlong <mijinlong@cn.fujitsu.com>
Date:   Wed Apr 27 09:09:58 2011 +0800

    nfsd41: compare request's opcnt with session's maxops at nfsd4_sequence
    
    Make sure nfs server errors out if request contains more ops
    than channel allows.
    
    Signed-off-by: Mi Jinlong <mijinlong@cn.fujitsu.com>
    [bfields@redhat.com: use helper function]
    Signed-off-by: J. Bruce Fields <bfields@redhat.com>

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index fbde6f7..487ba47 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -1721,6 +1721,13 @@ static void nfsd4_sequence_check_conn(struct nfsd4_conn *new, struct nfsd4_sessi
 	return;
 }
 
+static bool nfsd4_session_too_many_ops(struct svc_rqst *rqstp, struct nfsd4_session *session)
+{
+	struct nfsd4_compoundargs *args = rqstp->rq_argp;
+
+	return args->opcnt > session->se_fchannel.maxops;
+}
+
 __be32
 nfsd4_sequence(struct svc_rqst *rqstp,
 	       struct nfsd4_compound_state *cstate,
@@ -1749,6 +1756,10 @@ nfsd4_sequence(struct svc_rqst *rqstp,
 	if (!session)
 		goto out;
 
+	status = nfserr_too_many_ops;
+	if (nfsd4_session_too_many_ops(rqstp, session))
+		goto out;
+
 	status = nfserr_badslot;
 	if (seq->slotid >= session->se_fchannel.maxreqs)
 		goto out;