nfsd41: want delegation flags

index e8c98f0..a6cdbd5 100644
@@ -2633,7 +2633,7 @@ static __be32 nfsd4_check_seqid(struct nfsd4_compound_state *cstate, struct nfs4
 
 static int share_access_to_flags(u32 share_access)
 {
-	share_access &= ~NFS4_SHARE_WANT_MASK;
+	share_access &= NFS4_SHARE_ACCESS_MASK;
 
 	return share_access == NFS4_SHARE_ACCESS_READ ? RD_STATE : WR_STATE;
 }

index 896da74..a9040be 100644
@@ -310,9 +310,6 @@ static __be32 nfsd_check_obj_isreg(struct svc_fh *fh)
 	if (open->op_create && open->op_claim_type != NFS4_OPEN_CLAIM_NULL)
 		return nfserr_inval;
 
-	/* We don't yet support WANT bits: */
-	open->op_share_access &= NFS4_SHARE_ACCESS_MASK;
-
 	open->op_created = 0;
 	/*
 	 * RFC5661 18.51.3

index a6cdbd5..c165df7 100644
@@ -2633,8 +2633,6 @@ static __be32 nfsd4_check_seqid(struct nfsd4_compound_state *cstate, struct nfs4
 
 static int share_access_to_flags(u32 share_access)
 {
-	share_access &= NFS4_SHARE_ACCESS_MASK;
-
 	return share_access == NFS4_SHARE_ACCESS_READ ? RD_STATE : WR_STATE;
 }
 

@@ -3596,7 +3594,9 @@ static inline void nfs4_stateid_downgrade(struct nfs4_ol_stateid *stp, u32 to_ac
 			cstate->current_fh.fh_dentry->d_name.name);
 
 	/* We don't yet support WANT bits: */
-	od->od_share_access &= NFS4_SHARE_ACCESS_MASK;
+	if (od->od_deleg_want)
+		dprintk("NFSD: %s: od_deleg_want=0x%x ignored\n", __func__,
+			od->od_deleg_want);
 
 	nfs4_lock_state();
 	status = nfs4_preprocess_confirmed_seqid_op(cstate, od->od_seqid,

index 0ec5a1b..78d2bb8 100644
@@ -638,14 +638,18 @@ static __be32 nfsd4_decode_bind_conn_to_session(struct nfsd4_compoundargs *argp,
 	DECODE_TAIL;
 }
 
-static __be32 nfsd4_decode_share_access(struct nfsd4_compoundargs *argp, u32 *x)
+static __be32 nfsd4_decode_share_access(struct nfsd4_compoundargs *argp, u32 *share_access, u32 *deleg_want, u32 *deleg_when)
 {
 	__be32 *p;
 	u32 w;
 
 	READ_BUF(4);
 	READ32(w);
-	*x = w;
+	*share_access = w & NFS4_SHARE_ACCESS_MASK;
+	*deleg_want = w & NFS4_SHARE_WANT_MASK;
+	if (deleg_when)
+		*deleg_when = w & NFS4_SHARE_WHEN_MASK;
+
 	switch (w & NFS4_SHARE_ACCESS_MASK) {
 	case NFS4_SHARE_ACCESS_READ:
 	case NFS4_SHARE_ACCESS_WRITE:

@@ -673,6 +677,9 @@ static __be32 nfsd4_decode_share_access(struct nfsd4_compoundargs *argp, u32 *x)
 	w &= ~NFS4_SHARE_WANT_MASK;
 	if (!w)
 		return nfs_ok;
+
+	if (!deleg_when)	/* open_downgrade */
+		return nfserr_inval;
 	switch (w) {
 	case NFS4_SHARE_SIGNAL_DELEG_WHEN_RESRC_AVAIL:
 	case NFS4_SHARE_PUSH_DELEG_WHEN_UNCONTENDED:

@@ -719,6 +726,7 @@ static __be32 nfsd4_decode_opaque(struct nfsd4_compoundargs *argp, struct xdr_ne
 nfsd4_decode_open(struct nfsd4_compoundargs *argp, struct nfsd4_open *open)
 {
 	DECODE_HEAD;
+	u32 dummy;
 
 	memset(open->op_bmval, 0, sizeof(open->op_bmval));
 	open->op_iattr.ia_valid = 0;

@@ -727,7 +735,9 @@ static __be32 nfsd4_decode_opaque(struct nfsd4_compoundargs *argp, struct xdr_ne
 	/* seqid, share_access, share_deny, clientid, ownerlen */
 	READ_BUF(4);
 	READ32(open->op_seqid);
-	status = nfsd4_decode_share_access(argp, &open->op_share_access);
+	/* decode, yet ignore deleg_when until supported */
+	status = nfsd4_decode_share_access(argp, &open->op_share_access,
+					   &open->op_deleg_want, &dummy);
 	if (status)
 		goto xdr_error;
 	status = nfsd4_decode_share_deny(argp, &open->op_share_deny);

@@ -848,7 +858,8 @@ static __be32 nfsd4_decode_opaque(struct nfsd4_compoundargs *argp, struct xdr_ne
 		return status;
 	READ_BUF(4);
 	READ32(open_down->od_seqid);
-	status = nfsd4_decode_share_access(argp, &open_down->od_share_access);
+	status = nfsd4_decode_share_access(argp, &open_down->od_share_access,
+					   &open_down->od_deleg_want, NULL);
 	if (status)
 		return status;
 	status = nfsd4_decode_share_deny(argp, &open_down->od_share_deny);

index 2364747..1771a91 100644
@@ -222,6 +222,7 @@ struct nfsd4_open {
 	u32		op_seqid;           /* request */
 	u32		op_share_access;    /* request */
 	u32		op_share_deny;      /* request */
+	u32		op_deleg_want;      /* request */
 	stateid_t	op_stateid;         /* response */
 	u32		op_recall;          /* recall */
 	struct nfsd4_change_info  op_cinfo; /* response */

@@ -245,8 +246,9 @@ struct nfsd4_open_confirm {
 struct nfsd4_open_downgrade {
 	stateid_t       od_stateid;
 	u32             od_seqid;
-	u32             od_share_access;
-	u32             od_share_deny;
+	u32             od_share_access;	/* request */
+	u32		od_deleg_want;		/* request */
+	u32             od_share_deny;		/* request */
 };
 
 

index c165df7..ad21b06 100644
@@ -2862,7 +2862,7 @@ static int nfs4_set_delegation(struct nfs4_delegation *dp, int flag)
 	struct nfs4_delegation *dp;
 	struct nfs4_openowner *oo = container_of(stp->st_stateowner, struct nfs4_openowner, oo_owner);
 	int cb_up;
-	int status, flag = 0;
+	int status = 0, flag = 0;
 
 	cb_up = nfsd4_cb_channel_good(oo->oo_owner.so_client);
 	flag = NFS4_OPEN_DELEGATE_NONE;

@@ -2903,11 +2903,32 @@ static int nfs4_set_delegation(struct nfs4_delegation *dp, int flag)
 	dprintk("NFSD: delegation stateid=" STATEID_FMT "\n",
 		STATEID_VAL(&dp->dl_stid.sc_stateid));
 out:
-	if (open->op_claim_type == NFS4_OPEN_CLAIM_PREVIOUS
-			&& flag == NFS4_OPEN_DELEGATE_NONE
-			&& open->op_delegate_type != NFS4_OPEN_DELEGATE_NONE)
-		dprintk("NFSD: WARNING: refusing delegation reclaim\n");
 	open->op_delegate_type = flag;
+	if (flag == NFS4_OPEN_DELEGATE_NONE) {
+		if (open->op_claim_type == NFS4_OPEN_CLAIM_PREVIOUS &&
+		    open->op_delegate_type != NFS4_OPEN_DELEGATE_NONE)
+			dprintk("NFSD: WARNING: refusing delegation reclaim\n");
+
+		if (open->op_deleg_want) {
+			open->op_delegate_type = NFS4_OPEN_DELEGATE_NONE_EXT;
+			if (status == -EAGAIN)
+				open->op_why_no_deleg = WND4_CONTENTION;
+			else {
+				open->op_why_no_deleg = WND4_RESOURCE;
+				switch (open->op_deleg_want) {
+				case NFS4_SHARE_WANT_READ_DELEG:
+				case NFS4_SHARE_WANT_WRITE_DELEG:
+				case NFS4_SHARE_WANT_ANY_DELEG:
+					break;
+				case NFS4_SHARE_WANT_CANCEL:
+					open->op_why_no_deleg = WND4_CANCELLED;
+					break;
+				case NFS4_SHARE_WANT_NO_DELEG:
+					BUG();	/* not supposed to get here */
+				}
+			}
+		}
+	}
 	return;
 out_free:
 	nfs4_put_delegation(dp);

@@ -2977,20 +2998,45 @@ static int nfs4_set_delegation(struct nfs4_delegation *dp, int flag)
 	update_stateid(&stp->st_stid.sc_stateid);
 	memcpy(&open->op_stateid, &stp->st_stid.sc_stateid, sizeof(stateid_t));
 
-	if (nfsd4_has_session(&resp->cstate))
+	if (nfsd4_has_session(&resp->cstate)) {
 		open->op_openowner->oo_flags |= NFS4_OO_CONFIRMED;
 
+		if (open->op_deleg_want & NFS4_SHARE_WANT_NO_DELEG) {
+			open->op_delegate_type = NFS4_OPEN_DELEGATE_NONE_EXT;
+			open->op_why_no_deleg = WND4_NOT_WANTED;
+			goto nodeleg;
+		}
+	}
+
 	/*
 	* Attempt to hand out a delegation. No error return, because the
 	* OPEN succeeds even if we fail.
 	*/
 	nfs4_open_delegation(current_fh, open, stp);
-
+nodeleg:
 	status = nfs_ok;
 
 	dprintk("%s: stateid=" STATEID_FMT "\n", __func__,
 		STATEID_VAL(&stp->st_stid.sc_stateid));
 out:
+	/* 4.1 client trying to upgrade/downgrade delegation? */
+	if (open->op_delegate_type == NFS4_OPEN_DELEGATE_NONE && dp &&
+	    open->op_deleg_want) {
+		if (open->op_deleg_want == NFS4_SHARE_WANT_READ_DELEG &&
+		    dp->dl_type == NFS4_OPEN_DELEGATE_WRITE) {
+			open->op_delegate_type = NFS4_OPEN_DELEGATE_NONE_EXT;
+			open->op_why_no_deleg = WND4_NOT_SUPP_DOWNGRADE;
+		} else if (open->op_deleg_want == NFS4_SHARE_WANT_WRITE_DELEG &&
+			   dp->dl_type == NFS4_OPEN_DELEGATE_WRITE) {
+			open->op_delegate_type = NFS4_OPEN_DELEGATE_NONE_EXT;
+			open->op_why_no_deleg = WND4_NOT_SUPP_UPGRADE;
+		}
+		/* Otherwise the client must be confused wanting a delegation
+		 * it already has, therefore we don't return
+		 * NFS4_OPEN_DELEGATE_NONE_EXT and reason.
+		 */
+	}
+
 	if (fp)
 		put_nfs4_file(fp);
 	if (status == 0 && open->op_claim_type == NFS4_OPEN_CLAIM_PREVIOUS)

index 78d2bb8..c2cf857 100644
@@ -2862,6 +2862,20 @@ static __be32 nfsd4_encode_bind_conn_to_session(struct nfsd4_compoundres *resp,
 		WRITE32(0);   /* XXX: is NULL principal ok? */
 		ADJUST_ARGS();
 		break;
+	case NFS4_OPEN_DELEGATE_NONE_EXT: /* 4.1 */
+		switch (open->op_why_no_deleg) {
+		case WND4_CONTENTION:
+		case WND4_RESOURCE:
+			RESERVE_SPACE(8);
+			WRITE32(open->op_why_no_deleg);
+			WRITE32(0);	/* deleg signaling not supported yet */
+			break;
+		default:
+			RESERVE_SPACE(4);
+			WRITE32(open->op_why_no_deleg);
+		}
+		ADJUST_ARGS();
+		break;
 	default:
 		BUG();
 	}

index 1771a91..fea600f 100644
@@ -212,6 +212,7 @@ struct nfsd4_open {
 	struct xdr_netobj op_fname;	    /* request - everything but CLAIM_PREV */
 	u32		op_delegate_type;   /* request - CLAIM_PREV only */
 	stateid_t       op_delegate_stateid; /* request - response */
+	u32		op_why_no_deleg;    /* response - DELEG_NONE_EXT only */
 	u32		op_create;     	    /* request */
 	u32		op_createmode;      /* request */
 	u32		op_bmval[3];        /* request */

index 32345c2..8cdde4d 100644
@@ -441,7 +441,20 @@ enum limit_by4 {
 enum open_delegation_type4 {
 	NFS4_OPEN_DELEGATE_NONE = 0,
 	NFS4_OPEN_DELEGATE_READ = 1,
-	NFS4_OPEN_DELEGATE_WRITE = 2
+	NFS4_OPEN_DELEGATE_WRITE = 2,
+	NFS4_OPEN_DELEGATE_NONE_EXT = 3, /* 4.1 */
+};
+
+enum why_no_delegation4 { /* new to v4.1 */
+	WND4_NOT_WANTED = 0,
+	WND4_CONTENTION = 1,
+	WND4_RESOURCE = 2,
+	WND4_NOT_SUPP_FTYPE = 3,
+	WND4_WRITE_DELEG_NOT_SUPP_FTYPE = 4,
+	WND4_NOT_SUPP_UPGRADE = 5,
+	WND4_NOT_SUPP_DOWNGRADE = 6,
+	WND4_CANCELLED = 7,
+	WND4_IS_DIR = 8,
 };
 
 enum lock_type4 {

index ad21b06..94daab4 100644
@@ -2853,6 +2853,27 @@ static int nfs4_set_delegation(struct nfs4_delegation *dp, int flag)
 	return 0;
 }
 
+static void nfsd4_open_deleg_none_ext(struct nfsd4_open *open, int status)
+{
+	open->op_delegate_type = NFS4_OPEN_DELEGATE_NONE_EXT;
+	if (status == -EAGAIN)
+		open->op_why_no_deleg = WND4_CONTENTION;
+	else {
+		open->op_why_no_deleg = WND4_RESOURCE;
+		switch (open->op_deleg_want) {
+		case NFS4_SHARE_WANT_READ_DELEG:
+		case NFS4_SHARE_WANT_WRITE_DELEG:
+		case NFS4_SHARE_WANT_ANY_DELEG:
+			break;
+		case NFS4_SHARE_WANT_CANCEL:
+			open->op_why_no_deleg = WND4_CANCELLED;
+			break;
+		case NFS4_SHARE_WANT_NO_DELEG:
+			BUG();	/* not supposed to get here */
+		}
+	}
+}
+
 /*
  * Attempt to hand out a delegation.
  */

@@ -2909,25 +2930,9 @@ static int nfs4_set_delegation(struct nfs4_delegation *dp, int flag)
 		    open->op_delegate_type != NFS4_OPEN_DELEGATE_NONE)
 			dprintk("NFSD: WARNING: refusing delegation reclaim\n");
 
-		if (open->op_deleg_want) {
-			open->op_delegate_type = NFS4_OPEN_DELEGATE_NONE_EXT;
-			if (status == -EAGAIN)
-				open->op_why_no_deleg = WND4_CONTENTION;
-			else {
-				open->op_why_no_deleg = WND4_RESOURCE;
-				switch (open->op_deleg_want) {
-				case NFS4_SHARE_WANT_READ_DELEG:
-				case NFS4_SHARE_WANT_WRITE_DELEG:
-				case NFS4_SHARE_WANT_ANY_DELEG:
-					break;
-				case NFS4_SHARE_WANT_CANCEL:
-					open->op_why_no_deleg = WND4_CANCELLED;
-					break;
-				case NFS4_SHARE_WANT_NO_DELEG:
-					BUG();	/* not supposed to get here */
-				}
-			}
-		}
+		/* 4.1 client asking for a delegation? */
+		if (open->op_deleg_want)
+			nfsd4_open_deleg_none_ext(open, status);
 	}
 	return;
 out_free:

index 94daab4..5bfc846 100644
@@ -2942,6 +2942,24 @@ static void nfsd4_open_deleg_none_ext(struct nfsd4_open *open, int status)
 	goto out;
 }
 
+static void nfsd4_deleg_xgrade_none_ext(struct nfsd4_open *open,
+					struct nfs4_delegation *dp)
+{
+	if (open->op_deleg_want == NFS4_SHARE_WANT_READ_DELEG &&
+	    dp->dl_type == NFS4_OPEN_DELEGATE_WRITE) {
+		open->op_delegate_type = NFS4_OPEN_DELEGATE_NONE_EXT;
+		open->op_why_no_deleg = WND4_NOT_SUPP_DOWNGRADE;
+	} else if (open->op_deleg_want == NFS4_SHARE_WANT_WRITE_DELEG &&
+		   dp->dl_type == NFS4_OPEN_DELEGATE_WRITE) {
+		open->op_delegate_type = NFS4_OPEN_DELEGATE_NONE_EXT;
+		open->op_why_no_deleg = WND4_NOT_SUPP_UPGRADE;
+	}
+	/* Otherwise the client must be confused wanting a delegation
+	 * it already has, therefore we don't return
+	 * NFS4_OPEN_DELEGATE_NONE_EXT and reason.
+	 */
+}
+
 /*
  * called with nfs4_lock_state() held.
  */

@@ -3026,21 +3044,8 @@ static void nfsd4_open_deleg_none_ext(struct nfsd4_open *open, int status)
 out:
 	/* 4.1 client trying to upgrade/downgrade delegation? */
 	if (open->op_delegate_type == NFS4_OPEN_DELEGATE_NONE && dp &&
-	    open->op_deleg_want) {
-		if (open->op_deleg_want == NFS4_SHARE_WANT_READ_DELEG &&
-		    dp->dl_type == NFS4_OPEN_DELEGATE_WRITE) {
-			open->op_delegate_type = NFS4_OPEN_DELEGATE_NONE_EXT;
-			open->op_why_no_deleg = WND4_NOT_SUPP_DOWNGRADE;
-		} else if (open->op_deleg_want == NFS4_SHARE_WANT_WRITE_DELEG &&
-			   dp->dl_type == NFS4_OPEN_DELEGATE_WRITE) {
-			open->op_delegate_type = NFS4_OPEN_DELEGATE_NONE_EXT;
-			open->op_why_no_deleg = WND4_NOT_SUPP_UPGRADE;
-		}
-		/* Otherwise the client must be confused wanting a delegation
-		 * it already has, therefore we don't return
-		 * NFS4_OPEN_DELEGATE_NONE_EXT and reason.
-		 */
-	}
+	    open->op_deleg_want)
+		nfsd4_deleg_xgrade_none_ext(open, dp);
 
 	if (fp)
 		put_nfs4_file(fp);