svcrpc: simpler request dropping

Currently we use -EAGAIN returns to determine when to drop a deferred
request.  On its own, that is error-prone, as it makes us treat -EAGAIN
returns from other functions specially to prevent inadvertent dropping.

So, use a flag on the request instead.

Returning an error on request deferral is still required, to prevent
further processing, but we no longer need worry that an error return on
its own could result in a drop.

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

2 files changed, 3 insertions, 1 deletions

diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index 6359c42c4941..df1931f8ae98 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -1005,6 +1005,7 @@ svc_process_common(struct svc_rqst *rqstp, struct kvec *argv, struct kvec *resv)
         rqstp->rq_splice_ok = 1;
         /* Will be turned off only when NFSv4 Sessions are used */
         rqstp->rq_usedeferral = 1;
+        rqstp->rq_dropme = false;
 
         /* Setup reply header */
         rqstp->rq_xprt->xpt_ops->xpo_prep_reply_hdr(rqstp);
@@ -1106,7 +1107,7 @@ svc_process_common(struct svc_rqst *rqstp, struct kvec *argv, struct kvec *resv)
                 *statp = procp->pc_func(rqstp, rqstp->rq_argp, rqstp->rq_resp);
 
                 /* Encode reply */
-                if (*statp == rpc_drop_reply) {
+                if (rqstp->rq_dropme) {
                         if (procp->pc_release)
                                 procp->pc_release(rqstp, NULL, rqstp->rq_resp);
                         goto dropit;
diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index 5eae53b1e306..173f3b975d49 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -1019,6 +1019,7 @@ static struct cache_deferred_req *svc_defer(struct cache_req *req)
         }
         svc_xprt_get(rqstp->rq_xprt);
         dr->xprt = rqstp->rq_xprt;
+        rqstp->rq_dropme = true;
 
         dr->handle.revisit = svc_revisit;
         return &dr->handle;