[PATCH] NFSd: nfs4_preprocess_seqid_op should only set *stpp on success

[PATCH] NFSd: nfs4_preprocess_seqid_op should only set *stpp on success

[Jeff Layton]

From: Trond Myklebust <trond.myklebust@primarydata.com>

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
---
 fs/nfsd/nfs4state.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index f429883fb4bb..f8c61c2a0a9e 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -3897,6 +3897,7 @@ nfs4_preprocess_seqid_op(struct nfsd4_compound_state *cstate, u32 seqid,
 {
 	__be32 status;
 	struct nfs4_stid *s;
+	struct nfs4_ol_stateid *stp = NULL;
 
 	dprintk("NFSD: %s: seqid=%d stateid = " STATEID_FMT "\n", __func__,
 		seqid, STATEID_VAL(stateid));
@@ -3906,11 +3907,14 @@ nfs4_preprocess_seqid_op(struct nfsd4_compound_state *cstate, u32 seqid,
 				      cstate->minorversion, nn);
 	if (status)
 		return status;
-	*stpp = openlockstateid(s);
+	stp = openlockstateid(s);
 	if (!nfsd4_has_session(cstate))
-		cstate->replay_owner = (*stpp)->st_stateowner;
+		cstate->replay_owner = stp->st_stateowner;
 
-	return nfs4_seqid_op_checks(cstate, stateid, seqid, *stpp);
+	status = nfs4_seqid_op_checks(cstate, stateid, seqid, stp);
+	if (!status)
+		*stpp = stp;
+	return status;
 }
 
 static __be32 nfs4_preprocess_confirmed_seqid_op(struct nfsd4_compound_state *cstate, u32 seqid,
-- 
1.9.3

Re: [PATCH] NFSd: nfs4_preprocess_seqid_op should only set *stpp on success

[Christoph Hellwig]

On Fri, Jun 06, 2014 at 02:56:34PM -0400, Jeff Layton wrote:
> From: Trond Myklebust <trond.myklebust@primarydata.com>
> 
> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
> Signed-off-by: Jeff Layton <jlayton@primarydata.com>

The new code looks correct, but shouldn't callers already take care
not to use the returned stateid only if nfs4_preprocess_seqid_op returns
0?

Re: [PATCH] NFSd: nfs4_preprocess_seqid_op should only set *stpp on success

[Jeff Layton]

On Sat, 7 Jun 2014 07:08:00 -0700
Christoph Hellwig <hch@infradead.org> wrote:

> On Fri, Jun 06, 2014 at 02:56:34PM -0400, Jeff Layton wrote:
> > From: Trond Myklebust <trond.myklebust@primarydata.com>
> > 
> > Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
> > Signed-off-by: Jeff Layton <jlayton@primarydata.com>
> 
> The new code looks correct, but shouldn't callers already take care
> not to use the returned stateid only if nfs4_preprocess_seqid_op returns
> 0?
> 

Yeah, I mentioned that to Bruce on IRC. This is not really a bugfix,
per-se, but more of a defensive coding measure.

-- 
Jeff Layton <jlayton@primarydata.com>

Re: [PATCH] NFSd: nfs4_preprocess_seqid_op should only set *stpp on success

[Christoph Hellwig]

On Sat, Jun 07, 2014 at 10:23:26AM -0400, Jeff Layton wrote:
> Yeah, I mentioned that to Bruce on IRC. This is not really a bugfix,
> per-se, but more of a defensive coding measure.

Looks fine to me for that,

Reviewed-by: Christoph Hellwig <hch@lst.de>