NFSv4: Service delegation recall requests from the server.

Signed-off-by: Trond Myklebust <trond.myklebust@fys.uio.no>

fs/nfs/delegation.h

@@ -28,5 +28,6 @@ struct inode *nfs_delegation_find_inode(struct nfs4_client *clp, const struct nf
 void nfs_return_all_delegations(struct super_block *sb);
 /* NFSv4 delegation-related procedures */
 int nfs4_proc_delegreturn(struct inode *inode, struct rpc_cred *cred, const nfs4_stateid *stateid);
+int nfs4_open_delegation_recall(struct dentry *dentry, struct nfs4_state *state);
 
 #endif

fs/nfs/nfs4proc.c

@@ -196,9 +196,6 @@ static int _nfs4_open_reclaim(struct nfs4_state_owner *sp, struct nfs4_state *st
 {
 	struct inode *inode = state->inode;
 	struct nfs_server *server = NFS_SERVER(inode);
-	struct nfs_fattr fattr = {
-		.valid = 0,
-	};
 	struct nfs_openargs o_arg = {
 		.fh = NFS_FH(inode),
 		.seqid = sp->so_seqid,
@@ -209,11 +206,10 @@ static int _nfs4_open_reclaim(struct nfs4_state_owner *sp, struct nfs4_state *st
 		.bitmask = server->attr_bitmask,
 	};
 	struct nfs_openres o_res = {
-		.f_attr = &fattr,
 		.server = server,	/* Grrr */
 	};
 	struct rpc_message msg = {
-		.rpc_proc       = &nfs4_procedures[NFSPROC4_CLNT_OPEN_RECLAIM],
+		.rpc_proc       = &nfs4_procedures[NFSPROC4_CLNT_OPEN_NOATTR],
 		.rpc_argp       = &o_arg,
 		.rpc_resp	= &o_res,
 		.rpc_cred	= sp->so_cred,
@@ -222,10 +218,17 @@ static int _nfs4_open_reclaim(struct nfs4_state_owner *sp, struct nfs4_state *st
 
 	status = rpc_call_sync(server->client, &msg, 0);
 	nfs4_increment_seqid(status, sp);
-	if (status == 0)
+	if (status == 0) {
 		memcpy(&state->stateid, &o_res.stateid, sizeof(state->stateid));
-	/* Update the inode attributes */
-	nfs_refresh_inode(inode, &fattr);
+		if (o_res.delegation_type != 0) {
+			nfs_inode_set_delegation(inode, sp->so_cred, &o_res);
+			/* Did the server issue an immediate delegation recall? */
+			if (o_res.do_recall)
+				nfs_async_inode_return_delegation(inode, &o_res.stateid);
+		}
+	}
+	/* Ensure we update the inode attributes */
+	NFS_CACHEINV(inode);
 	return status;
 }
 
@@ -248,7 +251,76 @@ int nfs4_open_reclaim(struct nfs4_state_owner *sp, struct nfs4_state *state)
 	return err;
 }
 
-static int _nfs4_proc_open_confirm(struct rpc_clnt *clnt, const struct nfs_fhandle *fh, struct nfs4_state_owner *sp, nfs4_stateid *stateid)
+static int _nfs4_open_delegation_recall(struct dentry *dentry, struct nfs4_state *state)
+{
+	struct nfs4_state_owner  *sp  = state->owner;
+	struct inode *inode = dentry->d_inode;
+	struct nfs_server *server = NFS_SERVER(inode);
+	struct dentry *parent = dget_parent(dentry);
+	struct nfs_openargs arg = {
+		.fh = NFS_FH(parent->d_inode),
+		.clientid = server->nfs4_state->cl_clientid,
+		.name = &dentry->d_name,
+		.id = sp->so_id,
+		.server = server,
+		.bitmask = server->attr_bitmask,
+		.claim = NFS4_OPEN_CLAIM_DELEGATE_CUR,
+	};
+	struct nfs_openres res = {
+		.server = server,
+	};
+	struct 	rpc_message msg = {
+		.rpc_proc       = &nfs4_procedures[NFSPROC4_CLNT_OPEN_NOATTR],
+		.rpc_argp       = &arg,
+		.rpc_resp       = &res,
+		.rpc_cred	= sp->so_cred,
+	};
+	int status = 0;
+
+	down(&sp->so_sema);
+	if (!test_bit(NFS_DELEGATED_STATE, &state->flags))
+		goto out;
+	if (state->state == 0)
+		goto out;
+	arg.seqid = sp->so_seqid;
+	arg.open_flags = state->state;
+	memcpy(arg.u.delegation.data, state->stateid.data, sizeof(arg.u.delegation.data));
+	status = rpc_call_sync(server->client, &msg, 0);
+	nfs4_increment_seqid(status, sp);
+	if (status >= 0) {
+		memcpy(state->stateid.data, res.stateid.data,
+				sizeof(state->stateid.data));
+		clear_bit(NFS_DELEGATED_STATE, &state->flags);
+	}
+out:
+	up(&sp->so_sema);
+	dput(parent);
+	return status;
+}
+
+int nfs4_open_delegation_recall(struct dentry *dentry, struct nfs4_state *state)
+{
+	struct nfs4_exception exception = { };
+	struct nfs_server *server = NFS_SERVER(dentry->d_inode);
+	int err;
+	do {
+		err = _nfs4_open_delegation_recall(dentry, state);
+		switch (err) {
+			case 0:
+				return err;
+			case -NFS4ERR_STALE_CLIENTID:
+			case -NFS4ERR_STALE_STATEID:
+			case -NFS4ERR_EXPIRED:
+				/* Don't recall a delegation if it was lost */
+				nfs4_schedule_state_recovery(server->nfs4_state);
+				return err;
+		}
+		err = nfs4_handle_exception(server, err, &exception);
+	} while (exception.retry);
+	return err;
+}
+
+static int _nfs4_proc_open_confirm(struct rpc_clnt *clnt, const struct nfs_fh *fh, struct nfs4_state_owner *sp, nfs4_stateid *stateid)
 {
 	struct nfs_open_confirmargs arg = {
 		.fh             = fh,

fs/nfs/nfs4xdr.c

@@ -180,16 +180,14 @@ static int nfs_stat_to_errno(int);
 #define NFS4_dec_open_confirm_sz        (compound_decode_hdr_maxsz + \
                                         decode_putfh_maxsz + \
                                         op_decode_hdr_maxsz + 4)
-#define NFS4_enc_open_reclaim_sz	(compound_encode_hdr_maxsz + \
+#define NFS4_enc_open_noattr_sz	(compound_encode_hdr_maxsz + \
 					encode_putfh_maxsz + \
 					op_encode_hdr_maxsz + \
-					11 + \
-					encode_getattr_maxsz)
-#define NFS4_dec_open_reclaim_sz	(compound_decode_hdr_maxsz + \
+					11)
+#define NFS4_dec_open_noattr_sz	(compound_decode_hdr_maxsz + \
 					decode_putfh_maxsz + \
 					op_decode_hdr_maxsz + \
-					4 + 5 + 2 + 3 + \
-					decode_getattr_maxsz)
+					4 + 5 + 2 + 3)
 #define NFS4_enc_open_downgrade_sz \
 				(compound_encode_hdr_maxsz + \
                                 encode_putfh_maxsz + \
@@ -1425,13 +1423,13 @@ static int nfs4_xdr_enc_open_confirm(struct rpc_rqst *req, uint32_t *p, struct n
 }
 
 /*
- * Encode an OPEN request
+ * Encode an OPEN request with no attributes.
  */
-static int nfs4_xdr_enc_open_reclaim(struct rpc_rqst *req, uint32_t *p, struct nfs_openargs *args)
+static int nfs4_xdr_enc_open_noattr(struct rpc_rqst *req, uint32_t *p, struct nfs_openargs *args)
 {
 	struct xdr_stream xdr;
 	struct compound_hdr hdr = {
-		.nops   = 3,
+		.nops   = 2,
 	};
 	int status;
 
@@ -1441,9 +1439,6 @@ static int nfs4_xdr_enc_open_reclaim(struct rpc_rqst *req, uint32_t *p, struct n
 	if (status)
 		goto out;
 	status = encode_open(&xdr, args);
-	if (status)
-		goto out;
-	status = encode_getfattr(&xdr, args->bitmask);
 out:
 	return status;
 }
@@ -3491,9 +3486,9 @@ static int nfs4_xdr_dec_open_confirm(struct rpc_rqst *rqstp, uint32_t *p, struct
 }
 
 /*
- * Decode OPEN_RECLAIM response
+ * Decode OPEN response
  */
-static int nfs4_xdr_dec_open_reclaim(struct rpc_rqst *rqstp, uint32_t *p, struct nfs_openres *res)
+static int nfs4_xdr_dec_open_noattr(struct rpc_rqst *rqstp, uint32_t *p, struct nfs_openres *res)
 {
         struct xdr_stream xdr;
         struct compound_hdr hdr;
@@ -3507,11 +3502,6 @@ static int nfs4_xdr_dec_open_reclaim(struct rpc_rqst *rqstp, uint32_t *p, struct
         if (status)
                 goto out;
         status = decode_open(&xdr, res);
-        if (status)
-                goto out;
-	status = decode_getfattr(&xdr, res->f_attr, res->server);
-	if (status == NFS4ERR_DELAY)
-		status = 0;
 out:
         return status;
 }
@@ -3993,7 +3983,7 @@ struct rpc_procinfo	nfs4_procedures[] = {
   PROC(COMMIT,		enc_commit,	dec_commit),
   PROC(OPEN,		enc_open,	dec_open),
   PROC(OPEN_CONFIRM,	enc_open_confirm,	dec_open_confirm),
-  PROC(OPEN_RECLAIM,	enc_open_reclaim,	dec_open_reclaim),
+  PROC(OPEN_NOATTR,	enc_open_noattr,	dec_open_noattr),
   PROC(OPEN_DOWNGRADE,	enc_open_downgrade,	dec_open_downgrade),
   PROC(CLOSE,		enc_close,	dec_close),
   PROC(SETATTR,		enc_setattr,	dec_setattr),

include/linux/nfs4.h

@@ -355,7 +355,7 @@ enum {
 	NFSPROC4_CLNT_COMMIT,
 	NFSPROC4_CLNT_OPEN,
 	NFSPROC4_CLNT_OPEN_CONFIRM,
-	NFSPROC4_CLNT_OPEN_RECLAIM,
+	NFSPROC4_CLNT_OPEN_NOATTR,
 	NFSPROC4_CLNT_OPEN_DOWNGRADE,
 	NFSPROC4_CLNT_CLOSE,
 	NFSPROC4_CLNT_SETATTR,

include/linux/nfs_fs.h

@@ -630,6 +630,7 @@ struct nfs4_lock_state {
 /* bits for nfs4_state->flags */
 enum {
 	LK_STATE_IN_USE,
+	NFS_DELEGATED_STATE,
 };
 
 struct nfs4_state {