nfsd4: remove redundant encode buffer size checking

Now that all op encoders can handle running out of space, we no longer
need to check the remaining size for every operation; only nonidempotent
operations need that check, and that can be done by
nfsd4_check_resp_size.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

2 files changed, 13 insertions, 23 deletions

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 6a5b701961a4..a5b666ca560d 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1279,7 +1279,6 @@ nfsd4_proc_compound(struct svc_rqst *rqstp,
         struct nfsd4_compound_state *cstate = &resp->cstate;
         struct svc_fh *current_fh = &cstate->current_fh;
         struct svc_fh *save_fh = &cstate->save_fh;
-        int             slack_bytes;
         u32             plen = 0;
         __be32          status;
 
@@ -1333,19 +1332,6 @@ nfsd4_proc_compound(struct svc_rqst *rqstp,
                         goto encode_op;
                 }
 
-                /* We must be able to encode a successful response to
-                 * this operation, with enough room left over to encode a
-                 * failed response to the next operation.  If we don't
-                 * have enough room, fail with ERR_RESOURCE.
-                 */
-                slack_bytes = (char *)resp->xdr.end - (char *)resp->xdr.p;
-                if (slack_bytes < COMPOUND_SLACK_SPACE
-                                + COMPOUND_ERR_SLACK_SPACE) {
-                        BUG_ON(slack_bytes < COMPOUND_ERR_SLACK_SPACE);
-                        op->status = nfserr_resource;
-                        goto encode_op;
-                }
-
                 opdesc = OPDESC(op);
 
                 if (!current_fh->fh_dentry) {
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 89c65a3e09e4..df643e0fb6b3 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -3753,20 +3753,24 @@ static nfsd4_enc nfsd4_enc_ops[] = {
 __be32 nfsd4_check_resp_size(struct nfsd4_compoundres *resp, u32 pad)
 {
         struct xdr_buf *buf = &resp->rqstp->rq_res;
-        struct nfsd4_session *session = NULL;
+        struct nfsd4_session *session = resp->cstate.session;
         struct nfsd4_slot *slot = resp->cstate.slot;
+        int slack_bytes = (char *)resp->xdr.end - (char *)resp->xdr.p;
 
-        if (!nfsd4_has_session(&resp->cstate))
-                return 0;
+        if (nfsd4_has_session(&resp->cstate)) {
 
-        session = resp->cstate.session;
+                if (buf->len + pad > session->se_fchannel.maxresp_sz)
+                        return nfserr_rep_too_big;
 
-        if (buf->len + pad > session->se_fchannel.maxresp_sz)
-                return nfserr_rep_too_big;
+                if ((slot->sl_flags & NFSD4_SLOT_CACHETHIS) &&
+                    buf->len + pad > session->se_fchannel.maxresp_cached)
+                        return nfserr_rep_too_big_to_cache;
+        }
 
-        if ((slot->sl_flags & NFSD4_SLOT_CACHETHIS) &&
-            buf->len + pad > session->se_fchannel.maxresp_cached)
-                return nfserr_rep_too_big_to_cache;
+        if (pad > slack_bytes) {
+                WARN_ON_ONCE(nfsd4_has_session(&resp->cstate));
+                return nfserr_resource;
+        }
 
         return 0;
 }