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>

diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index 2bae1d86f5f241b8d62a61bf9ed8b5a0bcfc9c8e..18743c4d8bca848d493829f6385127f8e89508eb 100644 (file)
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -608,7 +608,7 @@ nfsd_dispatch(struct svc_rqst *rqstp, __be32 *statp)
        /* Now call the procedure handler, and encode NFS status. */
        nfserr = proc->pc_func(rqstp, rqstp->rq_argp, rqstp->rq_resp);
        nfserr = map_new_errors(rqstp->rq_vers, nfserr);
-       if (nfserr == nfserr_dropit) {
+       if (nfserr == nfserr_dropit || rqstp->rq_dropme) {
                dprintk("nfsd: Dropping request; may be revisited later\n");
                nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
                return 0;

diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h
index 5a3085b9b3941d8f67fd9dec1c0584f360cfb3f6..d45c482b64441ed368b05b92f9564f379076bf65 100644 (file)
--- a/include/linux/sunrpc/svc.h
+++ b/include/linux/sunrpc/svc.h
@@ -269,6 +269,7 @@ struct svc_rqst {
        struct cache_req        rq_chandle;     /* handle passed to caches for 
                                                 * request delaying 
                                                 */
+       bool                    rq_dropme;
        /* Catering to nfsd */
        struct auth_domain *    rq_client;      /* RPC peer info */
        struct auth_domain *    rq_gssclient;   /* "gss/"-style peer info */

diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index 6359c42c49410f73fbf9e8c7c570964f1ca739b1..df1931f8ae983122dadb235b64f6fbaf20fee5b9 100644 (file)
--- 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 5eae53b1e306d529c7347d463898b2114083e4e2..173f3b975d494e933a184e78b56dfdf6a6ab8de8 100644 (file)
--- 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;