Merge tag 'nfsd-4.14' of git://linux-nfs.org/~bfields/linux

Pull nfsd updates from Bruce Fields:
 "More RDMA work and some op-structure constification from Chuck Lever,
  and a small cleanup to our xdr encoding"

* tag 'nfsd-4.14' of git://linux-nfs.org/~bfields/linux:
  svcrdma: Estimate Send Queue depth properly
  rdma core: Add rdma_rw_mr_payload()
  svcrdma: Limit RQ depth
  svcrdma: Populate tail iovec when receiving
  nfsd: Incoming xdr_bufs may have content in tail buffer
  svcrdma: Clean up svc_rdma_build_read_chunk()
  sunrpc: Const-ify struct sv_serv_ops
  nfsd: Const-ify NFSv4 encoding and decoding ops arrays
  sunrpc: Const-ify instances of struct svc_xprt_ops
  nfsd4: individual encoders no longer see error cases
  nfsd4: skip encoder in trivial error cases
  nfsd4: define ->op_release for compound ops
  nfsd4: opdesc will be useful outside nfs4proc.c
  nfsd4: move some nfsd4 op definitions to xdr4.h

4 files changed, 233 insertions, 275 deletions

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index d27e75ad25e3..3c69db7d4905 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -784,6 +784,14 @@ out:
 	return status;
 }
 
+
+static void
+nfsd4_read_release(union nfsd4_op_u *u)
+{
+	if (u->read.rd_filp)
+		fput(u->read.rd_filp);
+}
+
 static __be32
 nfsd4_readdir(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 	      union nfsd4_op_u *u)
@@ -912,6 +920,13 @@ nfsd4_secinfo_no_name(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstat
 	return nfs_ok;
 }
 
+static void
+nfsd4_secinfo_release(union nfsd4_op_u *u)
+{
+	if (u->secinfo.si_exp)
+		exp_put(u->secinfo.si_exp);
+}
+
 static __be32
 nfsd4_setattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 	      union nfsd4_op_u *u)
@@ -1335,6 +1350,12 @@ out:
 	return nfserr;
 }
 
+static void
+nfsd4_getdeviceinfo_release(union nfsd4_op_u *u)
+{
+	kfree(u->getdeviceinfo.gd_device);
+}
+
 static __be32
 nfsd4_layoutget(struct svc_rqst *rqstp,
 		struct nfsd4_compound_state *cstate, union nfsd4_op_u *u)
@@ -1415,6 +1436,12 @@ out:
 	return nfserr;
 }
 
+static void
+nfsd4_layoutget_release(union nfsd4_op_u *u)
+{
+	kfree(u->layoutget.lg_content);
+}
+
 static __be32
 nfsd4_layoutcommit(struct svc_rqst *rqstp,
 		struct nfsd4_compound_state *cstate, union nfsd4_op_u *u)
@@ -1541,49 +1568,6 @@ static inline void nfsd4_increment_op_stats(u32 opnum)
 		nfsdstats.nfs4_opcount[opnum]++;
 }
 
-enum nfsd4_op_flags {
-	ALLOWED_WITHOUT_FH = 1 << 0,	/* No current filehandle required */
-	ALLOWED_ON_ABSENT_FS = 1 << 1,	/* ops processed on absent fs */
-	ALLOWED_AS_FIRST_OP = 1 << 2,	/* ops reqired first in compound */
-	/* For rfc 5661 section 2.6.3.1.1: */
-	OP_HANDLES_WRONGSEC = 1 << 3,
-	OP_IS_PUTFH_LIKE = 1 << 4,
-	/*
-	 * These are the ops whose result size we estimate before
-	 * encoding, to avoid performing an op then not being able to
-	 * respond or cache a response.  This includes writes and setattrs
-	 * as well as the operations usually called "nonidempotent":
-	 */
-	OP_MODIFIES_SOMETHING = 1 << 5,
-	/*
-	 * Cache compounds containing these ops in the xid-based drc:
-	 * We use the DRC for compounds containing non-idempotent
-	 * operations, *except* those that are 4.1-specific (since
-	 * sessions provide their own EOS), and except for stateful
-	 * operations other than setclientid and setclientid_confirm
-	 * (since sequence numbers provide EOS for open, lock, etc in
-	 * the v4.0 case).
-	 */
-	OP_CACHEME = 1 << 6,
-	/*
-	 * These are ops which clear current state id.
-	 */
-	OP_CLEAR_STATEID = 1 << 7,
-};
-
-struct nfsd4_operation {
-	__be32 (*op_func)(struct svc_rqst *, struct nfsd4_compound_state *,
-			union nfsd4_op_u *);
-	u32 op_flags;
-	char *op_name;
-	/* Try to get response size before operation */
-	u32 (*op_rsize_bop)(struct svc_rqst *, struct nfsd4_op *);
-	void (*op_get_currentstateid)(struct nfsd4_compound_state *,
-			union nfsd4_op_u *);
-	void (*op_set_currentstateid)(struct nfsd4_compound_state *,
-			union nfsd4_op_u *);
-};
-
 static const struct nfsd4_operation nfsd4_ops[];
 
 static const char *nfsd4_op_name(unsigned opnum);
@@ -1621,7 +1605,7 @@ static __be32 nfs41_check_op_ordering(struct nfsd4_compoundargs *args)
 	return nfs_ok;
 }
 
-static inline const struct nfsd4_operation *OPDESC(struct nfsd4_op *op)
+const struct nfsd4_operation *OPDESC(struct nfsd4_op *op)
 {
 	return &nfsd4_ops[op->opnum];
 }
@@ -1694,7 +1678,6 @@ nfsd4_proc_compound(struct svc_rqst *rqstp)
 	struct nfsd4_compoundargs *args = rqstp->rq_argp;
 	struct nfsd4_compoundres *resp = rqstp->rq_resp;
 	struct nfsd4_op	*op;
-	const struct nfsd4_operation *opdesc;
 	struct nfsd4_compound_state *cstate = &resp->cstate;
 	struct svc_fh *current_fh = &cstate->current_fh;
 	struct svc_fh *save_fh = &cstate->save_fh;
@@ -1747,15 +1730,13 @@ nfsd4_proc_compound(struct svc_rqst *rqstp)
 			goto encode_op;
 		}
 
-		opdesc = OPDESC(op);
-
 		if (!current_fh->fh_dentry) {
-			if (!(opdesc->op_flags & ALLOWED_WITHOUT_FH)) {
+			if (!(op->opdesc->op_flags & ALLOWED_WITHOUT_FH)) {
 				op->status = nfserr_nofilehandle;
 				goto encode_op;
 			}
 		} else if (current_fh->fh_export->ex_fslocs.migrated &&
-			  !(opdesc->op_flags & ALLOWED_ON_ABSENT_FS)) {
+			  !(op->opdesc->op_flags & ALLOWED_ON_ABSENT_FS)) {
 			op->status = nfserr_moved;
 			goto encode_op;
 		}
@@ -1763,12 +1744,12 @@ nfsd4_proc_compound(struct svc_rqst *rqstp)
 		fh_clear_wcc(current_fh);
 
 		/* If op is non-idempotent */
-		if (opdesc->op_flags & OP_MODIFIES_SOMETHING) {
+		if (op->opdesc->op_flags & OP_MODIFIES_SOMETHING) {
 			/*
 			 * Don't execute this op if we couldn't encode a
 			 * succesful reply:
 			 */
-			u32 plen = opdesc->op_rsize_bop(rqstp, op);
+			u32 plen = op->opdesc->op_rsize_bop(rqstp, op);
 			/*
 			 * Plus if there's another operation, make sure
 			 * we'll have space to at least encode an error:
@@ -1781,9 +1762,9 @@ nfsd4_proc_compound(struct svc_rqst *rqstp)
 		if (op->status)
 			goto encode_op;
 
-		if (opdesc->op_get_currentstateid)
-			opdesc->op_get_currentstateid(cstate, &op->u);
-		op->status = opdesc->op_func(rqstp, cstate, &op->u);
+		if (op->opdesc->op_get_currentstateid)
+			op->opdesc->op_get_currentstateid(cstate, &op->u);
+		op->status = op->opdesc->op_func(rqstp, cstate, &op->u);
 
 		/* Only from SEQUENCE */
 		if (cstate->status == nfserr_replay_cache) {
@@ -1792,10 +1773,10 @@ nfsd4_proc_compound(struct svc_rqst *rqstp)
 			goto out;
 		}
 		if (!op->status) {
-			if (opdesc->op_set_currentstateid)
-				opdesc->op_set_currentstateid(cstate, &op->u);
+			if (op->opdesc->op_set_currentstateid)
+				op->opdesc->op_set_currentstateid(cstate, &op->u);
 
-			if (opdesc->op_flags & OP_CLEAR_STATEID)
+			if (op->opdesc->op_flags & OP_CLEAR_STATEID)
 				clear_current_stateid(cstate);
 
 			if (need_wrongsec_check(rqstp))
@@ -2160,13 +2141,15 @@ static const struct nfsd4_operation nfsd4_ops[] = {
 	},
 	[OP_LOCK] = {
 		.op_func = nfsd4_lock,
-		.op_flags = OP_MODIFIES_SOMETHING,
+		.op_flags = OP_MODIFIES_SOMETHING |
+				OP_NONTRIVIAL_ERROR_ENCODE,
 		.op_name = "OP_LOCK",
 		.op_rsize_bop = nfsd4_lock_rsize,
 		.op_set_currentstateid = nfsd4_set_lockstateid,
 	},
 	[OP_LOCKT] = {
 		.op_func = nfsd4_lockt,
+		.op_flags = OP_NONTRIVIAL_ERROR_ENCODE,
 		.op_name = "OP_LOCKT",
 		.op_rsize_bop = nfsd4_lock_rsize,
 	},
@@ -2238,6 +2221,7 @@ static const struct nfsd4_operation nfsd4_ops[] = {
 	},
 	[OP_READ] = {
 		.op_func = nfsd4_read,
+		.op_release = nfsd4_read_release,
 		.op_name = "OP_READ",
 		.op_rsize_bop = nfsd4_read_rsize,
 		.op_get_currentstateid = nfsd4_get_readstateid,
@@ -2287,6 +2271,7 @@ static const struct nfsd4_operation nfsd4_ops[] = {
 	},
 	[OP_SECINFO] = {
 		.op_func = nfsd4_secinfo,
+		.op_release = nfsd4_secinfo_release,
 		.op_flags = OP_HANDLES_WRONGSEC,
 		.op_name = "OP_SECINFO",
 		.op_rsize_bop = nfsd4_secinfo_rsize,
@@ -2294,14 +2279,16 @@ static const struct nfsd4_operation nfsd4_ops[] = {
 	[OP_SETATTR] = {
 		.op_func = nfsd4_setattr,
 		.op_name = "OP_SETATTR",
-		.op_flags = OP_MODIFIES_SOMETHING | OP_CACHEME,
+		.op_flags = OP_MODIFIES_SOMETHING | OP_CACHEME
+				| OP_NONTRIVIAL_ERROR_ENCODE,
 		.op_rsize_bop = nfsd4_setattr_rsize,
 		.op_get_currentstateid = nfsd4_get_setattrstateid,
 	},
 	[OP_SETCLIENTID] = {
 		.op_func = nfsd4_setclientid,
 		.op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
-				| OP_MODIFIES_SOMETHING | OP_CACHEME,
+				| OP_MODIFIES_SOMETHING | OP_CACHEME
+				| OP_NONTRIVIAL_ERROR_ENCODE,
 		.op_name = "OP_SETCLIENTID",
 		.op_rsize_bop = nfsd4_setclientid_rsize,
 	},
@@ -2388,6 +2375,7 @@ static const struct nfsd4_operation nfsd4_ops[] = {
 	},
 	[OP_SECINFO_NO_NAME] = {
 		.op_func = nfsd4_secinfo_no_name,
+		.op_release = nfsd4_secinfo_release,
 		.op_flags = OP_HANDLES_WRONGSEC,
 		.op_name = "OP_SECINFO_NO_NAME",
 		.op_rsize_bop = nfsd4_secinfo_rsize,
@@ -2408,12 +2396,14 @@ static const struct nfsd4_operation nfsd4_ops[] = {
 #ifdef CONFIG_NFSD_PNFS
 	[OP_GETDEVICEINFO] = {
 		.op_func = nfsd4_getdeviceinfo,
+		.op_release = nfsd4_getdeviceinfo_release,
 		.op_flags = ALLOWED_WITHOUT_FH,
 		.op_name = "OP_GETDEVICEINFO",
 		.op_rsize_bop = nfsd4_getdeviceinfo_rsize,
 	},
 	[OP_LAYOUTGET] = {
 		.op_func = nfsd4_layoutget,
+		.op_release = nfsd4_layoutget_release,
 		.op_flags = OP_MODIFIES_SOMETHING,
 		.op_name = "OP_LAYOUTGET",
 		.op_rsize_bop = nfsd4_layoutget_rsize,
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 5f940d2a136b..2c61c6b8ae09 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -159,6 +159,25 @@ static __be32 *read_buf(struct nfsd4_compoundargs *argp, u32 nbytes)
 	 */
 	unsigned int avail = (char *)argp->end - (char *)argp->p;
 	__be32 *p;
+
+	if (argp->pagelen == 0) {
+		struct kvec *vec = &argp->rqstp->rq_arg.tail[0];
+
+		if (!argp->tail) {
+			argp->tail = true;
+			avail = vec->iov_len;
+			argp->p = vec->iov_base;
+			argp->end = vec->iov_base + avail;
+		}
+
+		if (avail < nbytes)
+			return NULL;
+
+		p = argp->p;
+		argp->p += XDR_QUADLEN(nbytes);
+		return p;
+	}
+
 	if (avail + argp->pagelen < nbytes)
 		return NULL;
 	if (avail + PAGE_SIZE < nbytes) /* need more than a page !! */
@@ -1778,7 +1797,7 @@ nfsd4_decode_notsupp(struct nfsd4_compoundargs *argp, void *p)
 
 typedef __be32(*nfsd4_dec)(struct nfsd4_compoundargs *argp, void *);
 
-static nfsd4_dec nfsd4_dec_ops[] = {
+static const nfsd4_dec nfsd4_dec_ops[] = {
 	[OP_ACCESS]		= (nfsd4_dec)nfsd4_decode_access,
 	[OP_CLOSE]		= (nfsd4_dec)nfsd4_decode_close,
 	[OP_COMMIT]		= (nfsd4_dec)nfsd4_decode_commit,
@@ -1927,6 +1946,7 @@ nfsd4_decode_compound(struct nfsd4_compoundargs *argp)
 			op->opnum = OP_ILLEGAL;
 			op->status = nfserr_op_illegal;
 		}
+		op->opdesc = OPDESC(op);
 		/*
 		 * We'll try to cache the result in the DRC if any one
 		 * op in the compound wants to be cached:
@@ -3102,14 +3122,12 @@ nfsd4_encode_access(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_
 	struct xdr_stream *xdr = &resp->xdr;
 	__be32 *p;
 
-	if (!nfserr) {
-		p = xdr_reserve_space(xdr, 8);
-		if (!p)
-			return nfserr_resource;
-		*p++ = cpu_to_be32(access->ac_supported);
-		*p++ = cpu_to_be32(access->ac_resp_access);
-	}
-	return nfserr;
+	p = xdr_reserve_space(xdr, 8);
+	if (!p)
+		return nfserr_resource;
+	*p++ = cpu_to_be32(access->ac_supported);
+	*p++ = cpu_to_be32(access->ac_resp_access);
+	return 0;
 }
 
 static __be32 nfsd4_encode_bind_conn_to_session(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_bind_conn_to_session *bcts)
@@ -3117,17 +3135,15 @@ static __be32 nfsd4_encode_bind_conn_to_session(struct nfsd4_compoundres *resp,
 	struct xdr_stream *xdr = &resp->xdr;
 	__be32 *p;
 
-	if (!nfserr) {
-		p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN + 8);
-		if (!p)
-			return nfserr_resource;
-		p = xdr_encode_opaque_fixed(p, bcts->sessionid.data,
-						NFS4_MAX_SESSIONID_LEN);
-		*p++ = cpu_to_be32(bcts->dir);
-		/* Upshifting from TCP to RDMA is not supported */
-		*p++ = cpu_to_be32(0);
-	}
-	return nfserr;
+	p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN + 8);
+	if (!p)
+		return nfserr_resource;
+	p = xdr_encode_opaque_fixed(p, bcts->sessionid.data,
+					NFS4_MAX_SESSIONID_LEN);
+	*p++ = cpu_to_be32(bcts->dir);
+	/* Upshifting from TCP to RDMA is not supported */
+	*p++ = cpu_to_be32(0);
+	return 0;
 }
 
 static __be32
@@ -3135,10 +3151,7 @@ nfsd4_encode_close(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_c
 {
 	struct xdr_stream *xdr = &resp->xdr;
 
-	if (!nfserr)
-		nfserr = nfsd4_encode_stateid(xdr, &close->cl_stateid);
-
-	return nfserr;
+	return nfsd4_encode_stateid(xdr, &close->cl_stateid);
 }
 
 
@@ -3148,14 +3161,12 @@ nfsd4_encode_commit(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_
 	struct xdr_stream *xdr = &resp->xdr;
 	__be32 *p;
 
-	if (!nfserr) {
-		p = xdr_reserve_space(xdr, NFS4_VERIFIER_SIZE);
-		if (!p)
-			return nfserr_resource;
-		p = xdr_encode_opaque_fixed(p, commit->co_verf.data,
+	p = xdr_reserve_space(xdr, NFS4_VERIFIER_SIZE);
+	if (!p)
+		return nfserr_resource;
+	p = xdr_encode_opaque_fixed(p, commit->co_verf.data,
 						NFS4_VERIFIER_SIZE);
-	}
-	return nfserr;
+	return 0;
 }
 
 static __be32
@@ -3164,15 +3175,13 @@ nfsd4_encode_create(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_
 	struct xdr_stream *xdr = &resp->xdr;
 	__be32 *p;
 
-	if (!nfserr) {
-		p = xdr_reserve_space(xdr, 20);
-		if (!p)
-			return nfserr_resource;
-		encode_cinfo(p, &create->cr_cinfo);
-		nfserr = nfsd4_encode_bitmap(xdr, create->cr_bmval[0],
-				create->cr_bmval[1], create->cr_bmval[2]);
-	}
-	return nfserr;
+	p = xdr_reserve_space(xdr, 20);
+	if (!p)
+		return nfserr_resource;
+	encode_cinfo(p, &create->cr_cinfo);
+	nfserr = nfsd4_encode_bitmap(xdr, create->cr_bmval[0],
+			create->cr_bmval[1], create->cr_bmval[2]);
+	return 0;
 }
 
 static __be32
@@ -3181,13 +3190,8 @@ nfsd4_encode_getattr(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4
 	struct svc_fh *fhp = getattr->ga_fhp;
 	struct xdr_stream *xdr = &resp->xdr;
 
-	if (nfserr)
-		return nfserr;
-
-	nfserr = nfsd4_encode_fattr(xdr, fhp, fhp->fh_export, fhp->fh_dentry,
-				    getattr->ga_bmval,
-				    resp->rqstp, 0);
-	return nfserr;
+	return nfsd4_encode_fattr(xdr, fhp, fhp->fh_export, fhp->fh_dentry,
+				    getattr->ga_bmval, resp->rqstp, 0);
 }
 
 static __be32
@@ -3198,14 +3202,12 @@ nfsd4_encode_getfh(struct nfsd4_compoundres *resp, __be32 nfserr, struct svc_fh
 	unsigned int len;
 	__be32 *p;
 
-	if (!nfserr) {
-		len = fhp->fh_handle.fh_size;
-		p = xdr_reserve_space(xdr, len + 4);
-		if (!p)
-			return nfserr_resource;
-		p = xdr_encode_opaque(p, &fhp->fh_handle.fh_base, len);
-	}
-	return nfserr;
+	len = fhp->fh_handle.fh_size;
+	p = xdr_reserve_space(xdr, len + 4);
+	if (!p)
+		return nfserr_resource;
+	p = xdr_encode_opaque(p, &fhp->fh_handle.fh_base, len);
+	return 0;
 }
 
 /*
@@ -3275,10 +3277,7 @@ nfsd4_encode_locku(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_l
 {
 	struct xdr_stream *xdr = &resp->xdr;
 
-	if (!nfserr)
-		nfserr = nfsd4_encode_stateid(xdr, &locku->lu_stateid);
-
-	return nfserr;
+	return nfsd4_encode_stateid(xdr, &locku->lu_stateid);
 }
 
 
@@ -3288,13 +3287,11 @@ nfsd4_encode_link(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_li
 	struct xdr_stream *xdr = &resp->xdr;
 	__be32 *p;
 
-	if (!nfserr) {
-		p = xdr_reserve_space(xdr, 20);
-		if (!p)
-			return nfserr_resource;
-		p = encode_cinfo(p, &link->li_cinfo);
-	}
-	return nfserr;
+	p = xdr_reserve_space(xdr, 20);
+	if (!p)
+		return nfserr_resource;
+	p = encode_cinfo(p, &link->li_cinfo);
+	return 0;
 }
 
 
@@ -3304,12 +3301,9 @@ nfsd4_encode_open(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_op
 	struct xdr_stream *xdr = &resp->xdr;
 	__be32 *p;
 
-	if (nfserr)
-		goto out;
-
 	nfserr = nfsd4_encode_stateid(xdr, &open->op_stateid);
 	if (nfserr)
-		goto out;
+		return nfserr;
 	p = xdr_reserve_space(xdr, 24);
 	if (!p)
 		return nfserr_resource;
@@ -3319,7 +3313,7 @@ nfsd4_encode_open(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_op
 	nfserr = nfsd4_encode_bitmap(xdr, open->op_bmval[0], open->op_bmval[1],
 					open->op_bmval[2]);
 	if (nfserr)
-		goto out;
+		return nfserr;
 
 	p = xdr_reserve_space(xdr, 4);
 	if (!p)
@@ -3392,8 +3386,7 @@ nfsd4_encode_open(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_op
 		BUG();
 	}
 	/* XXX save filehandle here */
-out:
-	return nfserr;
+	return 0;
 }
 
 static __be32
@@ -3401,10 +3394,7 @@ nfsd4_encode_open_confirm(struct nfsd4_compoundres *resp, __be32 nfserr, struct
 {
 	struct xdr_stream *xdr = &resp->xdr;
 
-	if (!nfserr)
-		nfserr = nfsd4_encode_stateid(xdr, &oc->oc_resp_stateid);
-
-	return nfserr;
+	return nfsd4_encode_stateid(xdr, &oc->oc_resp_stateid);
 }
 
 static __be32
@@ -3412,10 +3402,7 @@ nfsd4_encode_open_downgrade(struct nfsd4_compoundres *resp, __be32 nfserr, struc
 {
 	struct xdr_stream *xdr = &resp->xdr;
 
-	if (!nfserr)
-		nfserr = nfsd4_encode_stateid(xdr, &od->od_stateid);
-
-	return nfserr;
+	return nfsd4_encode_stateid(xdr, &od->od_stateid);
 }
 
 static __be32 nfsd4_encode_splice_read(
@@ -3552,20 +3539,15 @@ nfsd4_encode_read(struct nfsd4_compoundres *resp, __be32 nfserr,
 	struct raparms *ra = NULL;
 	__be32 *p;
 
-	if (nfserr)
-		goto out;
-
 	p = xdr_reserve_space(xdr, 8); /* eof flag and byte count */
 	if (!p) {
 		WARN_ON_ONCE(test_bit(RQ_SPLICE_OK, &resp->rqstp->rq_flags));
-		nfserr = nfserr_resource;
-		goto out;
+		return nfserr_resource;
 	}
 	if (resp->xdr.buf->page_len &&
 	    test_bit(RQ_SPLICE_OK, &resp->rqstp->rq_flags)) {
 		WARN_ON_ONCE(1);
-		nfserr = nfserr_resource;
-		goto out;
+		return nfserr_resource;
 	}
 	xdr_commit_encode(xdr);
 
@@ -3589,9 +3571,6 @@ nfsd4_encode_read(struct nfsd4_compoundres *resp, __be32 nfserr,
 	if (nfserr)
 		xdr_truncate_encode(xdr, starting_len);
 
-out:
-	if (file)
-		fput(file);
 	return nfserr;
 }
 
@@ -3605,9 +3584,6 @@ nfsd4_encode_readlink(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd
 	int length_offset = xdr->buf->len;
 	__be32 *p;
 
-	if (nfserr)
-		return nfserr;
-
 	p = xdr_reserve_space(xdr, 4);
 	if (!p)
 		return nfserr_resource;
@@ -3651,9 +3627,6 @@ nfsd4_encode_readdir(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4
 	int starting_len = xdr->buf->len;
 	__be32 *p;
 
-	if (nfserr)
-		return nfserr;
-
 	p = xdr_reserve_space(xdr, NFS4_VERIFIER_SIZE);
 	if (!p)
 		return nfserr_resource;
@@ -3739,13 +3712,11 @@ nfsd4_encode_remove(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_
 	struct xdr_stream *xdr = &resp->xdr;
 	__be32 *p;
 
-	if (!nfserr) {
-		p = xdr_reserve_space(xdr, 20);
-		if (!p)
-			return nfserr_resource;
-		p = encode_cinfo(p, &remove->rm_cinfo);
-	}
-	return nfserr;
+	p = xdr_reserve_space(xdr, 20);
+	if (!p)
+		return nfserr_resource;
+	p = encode_cinfo(p, &remove->rm_cinfo);
+	return 0;
 }
 
 static __be32
@@ -3754,19 +3725,16 @@ nfsd4_encode_rename(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_
 	struct xdr_stream *xdr = &resp->xdr;
 	__be32 *p;
 
-	if (!nfserr) {
-		p = xdr_reserve_space(xdr, 40);
-		if (!p)
-			return nfserr_resource;
-		p = encode_cinfo(p, &rename->rn_sinfo);
-		p = encode_cinfo(p, &rename->rn_tinfo);
-	}
-	return nfserr;
+	p = xdr_reserve_space(xdr, 40);
+	if (!p)
+		return nfserr_resource;
+	p = encode_cinfo(p, &rename->rn_sinfo);
+	p = encode_cinfo(p, &rename->rn_tinfo);
+	return 0;
 }
 
 static __be32
-nfsd4_do_encode_secinfo(struct xdr_stream *xdr,
-			 __be32 nfserr, struct svc_export *exp)
+nfsd4_do_encode_secinfo(struct xdr_stream *xdr, struct svc_export *exp)
 {
 	u32 i, nflavs, supported;
 	struct exp_flavor_info *flavs;
@@ -3774,9 +3742,6 @@ nfsd4_do_encode_secinfo(struct xdr_stream *xdr,
 	__be32 *p, *flavorsp;
 	static bool report = true;
 
-	if (nfserr)
-		goto out;
-	nfserr = nfserr_resource;
 	if (exp->ex_nflavors) {
 		flavs = exp->ex_flavors;
 		nflavs = exp->ex_nflavors;
@@ -3800,7 +3765,7 @@ nfsd4_do_encode_secinfo(struct xdr_stream *xdr,
 	supported = 0;
 	p = xdr_reserve_space(xdr, 4);
 	if (!p)
-		goto out;
+		return nfserr_resource;
 	flavorsp = p++;		/* to be backfilled later */
 
 	for (i = 0; i < nflavs; i++) {
@@ -3812,7 +3777,7 @@ nfsd4_do_encode_secinfo(struct xdr_stream *xdr,
 			p = xdr_reserve_space(xdr, 4 + 4 +
 					      XDR_LEN(info.oid.len) + 4 + 4);
 			if (!p)
-				goto out;
+				return nfserr_resource;
 			*p++ = cpu_to_be32(RPC_AUTH_GSS);
 			p = xdr_encode_opaque(p,  info.oid.data, info.oid.len);
 			*p++ = cpu_to_be32(info.qop);
@@ -3821,7 +3786,7 @@ nfsd4_do_encode_secinfo(struct xdr_stream *xdr,
 			supported++;
 			p = xdr_reserve_space(xdr, 4);
 			if (!p)
-				goto out;
+				return nfserr_resource;
 			*p++ = cpu_to_be32(pf);
 		} else {
 			if (report)
@@ -3833,11 +3798,7 @@ nfsd4_do_encode_secinfo(struct xdr_stream *xdr,
 	if (nflavs != supported)
 		report = false;
 	*flavorsp = htonl(supported);
-	nfserr = 0;
-out:
-	if (exp)
-		exp_put(exp);
-	return nfserr;
+	return 0;
 }
 
 static __be32
@@ -3846,7 +3807,7 @@ nfsd4_encode_secinfo(struct nfsd4_compoundres *resp, __be32 nfserr,
 {
 	struct xdr_stream *xdr = &resp->xdr;
 
-	return nfsd4_do_encode_secinfo(xdr, nfserr, secinfo->si_exp);
+	return nfsd4_do_encode_secinfo(xdr, secinfo->si_exp);
 }
 
 static __be32
@@ -3855,7 +3816,7 @@ nfsd4_encode_secinfo_no_name(struct nfsd4_compoundres *resp, __be32 nfserr,
 {
 	struct xdr_stream *xdr = &resp->xdr;
 
-	return nfsd4_do_encode_secinfo(xdr, nfserr, secinfo->sin_exp);
+	return nfsd4_do_encode_secinfo(xdr, secinfo->sin_exp);
 }
 
 /*
@@ -3916,16 +3877,14 @@ nfsd4_encode_write(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_w
 	struct xdr_stream *xdr = &resp->xdr;
 	__be32 *p;
 
-	if (!nfserr) {
-		p = xdr_reserve_space(xdr, 16);
-		if (!p)
-			return nfserr_resource;
-		*p++ = cpu_to_be32(write->wr_bytes_written);
-		*p++ = cpu_to_be32(write->wr_how_written);
-		p = xdr_encode_opaque_fixed(p, write->wr_verifier.data,
-							NFS4_VERIFIER_SIZE);
-	}
-	return nfserr;
+	p = xdr_reserve_space(xdr, 16);
+	if (!p)
+		return nfserr_resource;
+	*p++ = cpu_to_be32(write->wr_bytes_written);
+	*p++ = cpu_to_be32(write->wr_how_written);
+	p = xdr_encode_opaque_fixed(p, write->wr_verifier.data,
+						NFS4_VERIFIER_SIZE);
+	return 0;
 }
 
 static __be32
@@ -3938,12 +3897,8 @@ nfsd4_encode_exchange_id(struct nfsd4_compoundres *resp, __be32 nfserr,
 	char *server_scope;
 	int major_id_sz;
 	int server_scope_sz;
-	int status = 0;
 	uint64_t minor_id = 0;
 
-	if (nfserr)
-		return nfserr;
-
 	major_id = utsname()->nodename;
 	major_id_sz = strlen(major_id);
 	server_scope = utsname()->nodename;
@@ -3968,19 +3923,19 @@ nfsd4_encode_exchange_id(struct nfsd4_compoundres *resp, __be32 nfserr,
 		break;
 	case SP4_MACH_CRED:
 		/* spo_must_enforce bitmap: */
-		status = nfsd4_encode_bitmap(xdr,
+		nfserr = nfsd4_encode_bitmap(xdr,
 					exid->spo_must_enforce[0],
 					exid->spo_must_enforce[1],
 					exid->spo_must_enforce[2]);
-		if (status)
-			goto out;
+		if (nfserr)
+			return nfserr;
 		/* spo_must_allow bitmap: */
-		status = nfsd4_encode_bitmap(xdr,
+		nfserr = nfsd4_encode_bitmap(xdr,
 					exid->spo_must_allow[0],
 					exid->spo_must_allow[1],
 					exid->spo_must_allow[2]);
-		if (status)
-			goto out;
+		if (nfserr)
+			return nfserr;
 		break;
 	default:
 		WARN_ON_ONCE(1);
@@ -4007,8 +3962,6 @@ nfsd4_encode_exchange_id(struct nfsd4_compoundres *resp, __be32 nfserr,
 	/* Implementation id */
 	*p++ = cpu_to_be32(0);	/* zero length nfs_impl_id4 array */
 	return 0;
-out:
-	return status;
 }
 
 static __be32
@@ -4018,9 +3971,6 @@ nfsd4_encode_create_session(struct nfsd4_compoundres *resp, __be32 nfserr,
 	struct xdr_stream *xdr = &resp->xdr;
 	__be32 *p;
 
-	if (nfserr)
-		return nfserr;
-
 	p = xdr_reserve_space(xdr, 24);
 	if (!p)
 		return nfserr_resource;
@@ -4074,9 +4024,6 @@ nfsd4_encode_sequence(struct nfsd4_compoundres *resp, __be32 nfserr,
 	struct xdr_stream *xdr = &resp->xdr;
 	__be32 *p;
 
-	if (nfserr)
-		return nfserr;
-
 	p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN + 20);
 	if (!p)
 		return nfserr_resource;
@@ -4101,9 +4048,6 @@ nfsd4_encode_test_stateid(struct nfsd4_compoundres *resp, __be32 nfserr,
 	struct nfsd4_test_stateid_id *stateid, *next;
 	__be32 *p;
 
-	if (nfserr)
-		return nfserr;
-
 	p = xdr_reserve_space(xdr, 4 + (4 * test_stateid->ts_num_ids));
 	if (!p)
 		return nfserr_resource;
@@ -4113,7 +4057,7 @@ nfsd4_encode_test_stateid(struct nfsd4_compoundres *resp, __be32 nfserr,
 		*p++ = stateid->ts_id_status;
 	}
 
-	return nfserr;
+	return 0;
 }
 
 #ifdef CONFIG_NFSD_PNFS
@@ -4126,14 +4070,9 @@ nfsd4_encode_getdeviceinfo(struct nfsd4_compoundres *resp, __be32 nfserr,
 	u32 starting_len = xdr->buf->len, needed_len;
 	__be32 *p;
 
-	dprintk("%s: err %d\n", __func__, be32_to_cpu(nfserr));
-	if (nfserr)
-		goto out;
-
-	nfserr = nfserr_resource;
 	p = xdr_reserve_space(xdr, 4);
 	if (!p)
-		goto out;
+		return nfserr_resource;
 
 	*p++ = cpu_to_be32(gdev->gd_layout_type);
 
@@ -4149,42 +4088,33 @@ nfsd4_encode_getdeviceinfo(struct nfsd4_compoundres *resp, __be32 nfserr,
 			 */
 			if (xdr->buf->len + 4 > gdev->gd_maxcount)
 				goto toosmall;
-			goto out;
+			return nfserr;
 		}
 	}
 
-	nfserr = nfserr_resource;
 	if (gdev->gd_notify_types) {
 		p = xdr_reserve_space(xdr, 4 + 4);
 		if (!p)
-			goto out;
+			return nfserr_resource;
 		*p++ = cpu_to_be32(1);			/* bitmap length */
 		*p++ = cpu_to_be32(gdev->gd_notify_types);
 	} else {
 		p = xdr_reserve_space(xdr, 4);
 		if (!p)
-			goto out;
+			return nfserr_resource;
 		*p++ = 0;
 	}
 
-	nfserr = 0;
-out:
-	kfree(gdev->gd_device);
-	dprintk("%s: done: %d\n", __func__, be32_to_cpu(nfserr));
-	return nfserr;
-
+	return 0;
 toosmall:
 	dprintk("%s: maxcount too small\n", __func__);
 	needed_len = xdr->buf->len + 4 /* notifications */;
 	xdr_truncate_encode(xdr, starting_len);
 	p = xdr_reserve_space(xdr, 4);
-	if (!p) {
-		nfserr = nfserr_resource;
-	} else {
-		*p++ = cpu_to_be32(needed_len);
-		nfserr = nfserr_toosmall;
-	}
-	goto out;
+	if (!p)
+		return nfserr_resource;
+	*p++ = cpu_to_be32(needed_len);
+	return nfserr_toosmall;
 }
 
 static __be32
@@ -4195,14 +4125,9 @@ nfsd4_encode_layoutget(struct nfsd4_compoundres *resp, __be32 nfserr,
 	const struct nfsd4_layout_ops *ops;
 	__be32 *p;
 
-	dprintk("%s: err %d\n", __func__, nfserr);
-	if (nfserr)
-		goto out;
-
-	nfserr = nfserr_resource;
 	p = xdr_reserve_space(xdr, 36 + sizeof(stateid_opaque_t));
 	if (!p)
-		goto out;
+		return nfserr_resource;
 
 	*p++ = cpu_to_be32(1);	/* we always set return-on-close */
 	*p++ = cpu_to_be32(lgp->lg_sid.si_generation);
@@ -4216,10 +4141,7 @@ nfsd4_encode_layoutget(struct nfsd4_compoundres *resp, __be32 nfserr,
 	*p++ = cpu_to_be32(lgp->lg_layout_type);
 
 	ops = nfsd4_layout_ops[lgp->lg_layout_type];
-	nfserr = ops->encode_layoutget(xdr, lgp);
-out:
-	kfree(lgp->lg_content);
-	return nfserr;
+	return ops->encode_layoutget(xdr, lgp);
 }
 
 static __be32
@@ -4229,9 +4151,6 @@ nfsd4_encode_layoutcommit(struct nfsd4_compoundres *resp, __be32 nfserr,
 	struct xdr_stream *xdr = &resp->xdr;
 	__be32 *p;
 
-	if (nfserr)
-		return nfserr;
-
 	p = xdr_reserve_space(xdr, 4);
 	if (!p)
 		return nfserr_resource;
@@ -4243,7 +4162,7 @@ nfsd4_encode_layoutcommit(struct nfsd4_compoundres *resp, __be32 nfserr,
 		p = xdr_encode_hyper(p, lcp->lc_newsize);
 	}
 
-	return nfs_ok;
+	return 0;
 }
 
 static __be32
@@ -4253,16 +4172,13 @@ nfsd4_encode_layoutreturn(struct nfsd4_compoundres *resp, __be32 nfserr,
 	struct xdr_stream *xdr = &resp->xdr;
 	__be32 *p;
 
-	if (nfserr)
-		return nfserr;
-
 	p = xdr_reserve_space(xdr, 4);
 	if (!p)
 		return nfserr_resource;
 	*p++ = cpu_to_be32(lrp->lrs_present);
 	if (lrp->lrs_present)
 		return nfsd4_encode_stateid(xdr, &lrp->lr_sid);
-	return nfs_ok;
+	return 0;
 }
 #endif /* CONFIG_NFSD_PNFS */
 
@@ -4289,16 +4205,14 @@ nfsd4_encode_copy(struct nfsd4_compoundres *resp, __be32 nfserr,
 {
 	__be32 *p;
 
-	if (!nfserr) {
-		nfserr = nfsd42_encode_write_res(resp, &copy->cp_res);
-		if (nfserr)
-			return nfserr;
+	nfserr = nfsd42_encode_write_res(resp, &copy->cp_res);
+	if (nfserr)
+		return nfserr;
 
-		p = xdr_reserve_space(&resp->xdr, 4 + 4);
-		*p++ = cpu_to_be32(copy->cp_consecutive);
-		*p++ = cpu_to_be32(copy->cp_synchronous);
-	}
-	return nfserr;
+	p = xdr_reserve_space(&resp->xdr, 4 + 4);
+	*p++ = cpu_to_be32(copy->cp_consecutive);
+	*p++ = cpu_to_be32(copy->cp_synchronous);
+	return 0;
 }
 
 static __be32
@@ -4307,14 +4221,11 @@ nfsd4_encode_seek(struct nfsd4_compoundres *resp, __be32 nfserr,
 {
 	__be32 *p;
 
-	if (nfserr)
-		return nfserr;
-
 	p = xdr_reserve_space(&resp->xdr, 4 + 8);
 	*p++ = cpu_to_be32(seek->seek_eof);
 	p = xdr_encode_hyper(p, seek->seek_pos);
 
-	return nfserr;
+	return 0;
 }
 
 static __be32
@@ -4330,7 +4241,7 @@ typedef __be32(* nfsd4_enc)(struct nfsd4_compoundres *, __be32, void *);
  * since we don't need to filter out obsolete ops as this is
  * done in the decoding phase.
  */
-static nfsd4_enc nfsd4_enc_ops[] = {
+static const nfsd4_enc nfsd4_enc_ops[] = {
 	[OP_ACCESS]		= (nfsd4_enc)nfsd4_encode_access,
 	[OP_CLOSE]		= (nfsd4_enc)nfsd4_encode_close,
 	[OP_COMMIT]		= (nfsd4_enc)nfsd4_encode_commit,
@@ -4449,6 +4360,7 @@ nfsd4_encode_operation(struct nfsd4_compoundres *resp, struct nfsd4_op *op)
 	struct xdr_stream *xdr = &resp->xdr;
 	struct nfs4_stateowner *so = resp->cstate.replay_owner;
 	struct svc_rqst *rqstp = resp->rqstp;
+	const struct nfsd4_operation *opdesc = op->opdesc;
 	int post_err_offset;
 	nfsd4_enc encoder;
 	__be32 *p;
@@ -4463,10 +4375,15 @@ nfsd4_encode_operation(struct nfsd4_compoundres *resp, struct nfsd4_op *op)
 
 	if (op->opnum == OP_ILLEGAL)
 		goto status;
+	if (op->status && opdesc &&
+			!(opdesc->op_flags & OP_NONTRIVIAL_ERROR_ENCODE))
+		goto status;
 	BUG_ON(op->opnum < 0 || op->opnum >= ARRAY_SIZE(nfsd4_enc_ops) ||
 	       !nfsd4_enc_ops[op->opnum]);
 	encoder = nfsd4_enc_ops[op->opnum];
 	op->status = encoder(resp, op->status, &op->u);
+	if (opdesc && opdesc->op_release)
+		opdesc->op_release(&op->u);
 	xdr_commit_encode(xdr);
 
 	/* nfsd4_check_resp_size guarantees enough room for error status */
@@ -4573,6 +4490,7 @@ nfs4svc_decode_compoundargs(struct svc_rqst *rqstp, __be32 *p)
 	args->end = rqstp->rq_arg.head[0].iov_base + rqstp->rq_arg.head[0].iov_len;
 	args->pagelist = rqstp->rq_arg.pages;
 	args->pagelen = rqstp->rq_arg.page_len;
+	args->tail = false;
 	args->tmpp = NULL;
 	args->to_free = NULL;
 	args->ops = args->iops;
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index 063ae7de2c12..7e3af3ef0917 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -475,7 +475,7 @@ static int nfsd_get_default_max_blksize(void)
 	return ret;
 }
 
-static struct svc_serv_ops nfsd_thread_sv_ops = {
+static const struct svc_serv_ops nfsd_thread_sv_ops = {
 	.svo_shutdown		= nfsd_last_thread,
 	.svo_function		= nfsd,
 	.svo_enqueue_xprt	= svc_xprt_do_enqueue,
diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h
index 72c6ad136107..1e4edbf70052 100644
--- a/fs/nfsd/xdr4.h
+++ b/fs/nfsd/xdr4.h
@@ -538,6 +538,7 @@ struct nfsd4_seek {
 
 struct nfsd4_op {
 	int					opnum;
+	const struct nfsd4_operation *		opdesc;
 	__be32					status;
 	union nfsd4_op_u {
 		struct nfsd4_access		access;
@@ -614,6 +615,7 @@ struct nfsd4_compoundargs {
 	__be32 *			end;
 	struct page **			pagelist;
 	int				pagelen;
+	bool				tail;
 	__be32				tmp[8];
 	__be32 *			tmpp;
 	struct svcxdr_tmpbuf		*to_free;
@@ -661,6 +663,7 @@ static inline bool nfsd4_last_compound_op(struct svc_rqst *rqstp)
 	return argp->opcnt == resp->opcnt;
 }
 
+const struct nfsd4_operation *OPDESC(struct nfsd4_op *op);
 int nfsd4_max_reply(struct svc_rqst *rqstp, struct nfsd4_op *op);
 void warn_on_nonidempotent_op(struct nfsd4_op *op);
 
@@ -748,6 +751,53 @@ extern __be32 nfsd4_free_stateid(struct svc_rqst *rqstp,
 		struct nfsd4_compound_state *, union nfsd4_op_u *);
 extern void nfsd4_bump_seqid(struct nfsd4_compound_state *, __be32 nfserr);
 
+enum nfsd4_op_flags {
+	ALLOWED_WITHOUT_FH = 1 << 0,    /* No current filehandle required */
+	ALLOWED_ON_ABSENT_FS = 1 << 1,  /* ops processed on absent fs */
+	ALLOWED_AS_FIRST_OP = 1 << 2,   /* ops reqired first in compound */
+	/* For rfc 5661 section 2.6.3.1.1: */
+	OP_HANDLES_WRONGSEC = 1 << 3,
+	OP_IS_PUTFH_LIKE = 1 << 4,
+	/*
+	 * These are the ops whose result size we estimate before
+	 * encoding, to avoid performing an op then not being able to
+	 * respond or cache a response.  This includes writes and setattrs
+	 * as well as the operations usually called "nonidempotent":
+	 */
+	OP_MODIFIES_SOMETHING = 1 << 5,
+	/*
+	 * Cache compounds containing these ops in the xid-based drc:
+	 * We use the DRC for compounds containing non-idempotent
+	 * operations, *except* those that are 4.1-specific (since
+	 * sessions provide their own EOS), and except for stateful
+	 * operations other than setclientid and setclientid_confirm
+	 * (since sequence numbers provide EOS for open, lock, etc in
+	 * the v4.0 case).
+	 */
+	OP_CACHEME = 1 << 6,
+	/*
+	 * These are ops which clear current state id.
+	 */
+	OP_CLEAR_STATEID = 1 << 7,
+	/* Most ops return only an error on failure; some may do more: */
+	OP_NONTRIVIAL_ERROR_ENCODE = 1 << 8,
+};
+
+struct nfsd4_operation {
+	__be32 (*op_func)(struct svc_rqst *, struct nfsd4_compound_state *,
+			union nfsd4_op_u *);
+	void (*op_release)(union nfsd4_op_u *);
+	u32 op_flags;
+	char *op_name;
+	/* Try to get response size before operation */
+	u32 (*op_rsize_bop)(struct svc_rqst *, struct nfsd4_op *);
+	void (*op_get_currentstateid)(struct nfsd4_compound_state *,
+			union nfsd4_op_u *);
+	void (*op_set_currentstateid)(struct nfsd4_compound_state *,
+			union nfsd4_op_u *);
+};
+
+
 #endif
 
 /*