nfsd4: allow space for final error return

This post-encoding check should be taking into account the need to
encode at least an out-of-space error to the following op (if any).

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 7 insertions, 2 deletions

diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 24ba652008db..2ed803662b09 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -3636,6 +3636,7 @@ void
 nfsd4_encode_operation(struct nfsd4_compoundres *resp, struct nfsd4_op *op)
 {
         struct nfs4_stateowner *so = resp->cstate.replay_owner;
+        struct svc_rqst *rqstp = resp->rqstp;
         __be32 *statp;
         nfsd4_enc encoder;
         __be32 *p;
@@ -3652,8 +3653,12 @@ nfsd4_encode_operation(struct nfsd4_compoundres *resp, struct nfsd4_op *op)
         encoder = nfsd4_enc_ops[op->opnum];
         op->status = encoder(resp, op->status, &op->u);
         /* nfsd4_check_resp_size guarantees enough room for error status */
-        if (!op->status)
-                op->status = nfsd4_check_resp_size(resp, 0);
+        if (!op->status) {
+                int space_needed = 0;
+                if (!nfsd4_last_compound_op(rqstp))
+                        space_needed = COMPOUND_ERR_SLACK_SPACE;
+                op->status = nfsd4_check_resp_size(resp, space_needed);
+        }
         if (op->status == nfserr_resource ||
             op->status == nfserr_rep_too_big ||
             op->status == nfserr_rep_too_big_to_cache) {