[PATCH RFC 21/24] nfs: add a GDD_GETATTR rpc operation

[Jeff Layton <jlayton@kernel.org>]

Add a new compound that does a GET_DIR_DELEGATION just before doing a
GETATTR on an inode. Add a delegation stateid and a nf_status code to
struct nfs4_getattr_res to store the result.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
 fs/nfs/nfs4xdr.c        | 136 ++++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/nfs4.h    |   1 +
 include/linux/nfs_xdr.h |   2 +
 3 files changed, 139 insertions(+)

diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 1416099dfcd1..c28025018bda 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -391,6 +391,22 @@ static int decode_layoutget(struct xdr_stream *xdr, struct rpc_rqst *req,
 				XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN) + 5)
 #define encode_reclaim_complete_maxsz	(op_encode_hdr_maxsz + 4)
 #define decode_reclaim_complete_maxsz	(op_decode_hdr_maxsz + 4)
+#define encode_get_dir_delegation_maxsz (op_encode_hdr_maxsz +				\
+					 4 /* gdda_signal_deleg_avail */ +		\
+					 8 /* gdda_notification_types */ +		\
+					 nfstime4_maxsz  /* gdda_child_attr_delay */ +	\
+					 nfstime4_maxsz  /* gdda_dir_attr_delay */ +	\
+					 nfs4_fattr_bitmap_maxsz /* gdda_child_attributes */ + \
+					 nfs4_fattr_bitmap_maxsz /* gdda_dir_attributes */)
+
+#define decode_get_dir_delegation_maxsz (op_encode_hdr_maxsz +				\
+					 4 /* gddrnf_status */ +			\
+					 encode_verifier_maxsz /* gddr_cookieverf */ +	\
+					 encode_stateid_maxsz /* gddr_stateid */ +	\
+					 8 /* gddr_notification */ +			\
+					 nfs4_fattr_bitmap_maxsz /* gddr_child_attributes */ + \
+					 nfs4_fattr_bitmap_maxsz /* gddr_dir_attributes */)
+
 #define encode_getdeviceinfo_maxsz (op_encode_hdr_maxsz + \
 				XDR_QUADLEN(NFS4_DEVICEID4_SIZE) + \
 				1 /* layout type */ + \
@@ -636,6 +652,18 @@ static int decode_layoutget(struct xdr_stream *xdr, struct rpc_rqst *req,
 				decode_putfh_maxsz + \
 				decode_getattr_maxsz + \
 				decode_renew_maxsz)
+#define NFS4_enc_gdd_getattr_sz	(compound_encode_hdr_maxsz + \
+				encode_sequence_maxsz + \
+				encode_putfh_maxsz + \
+				encode_get_dir_delegation_maxsz + \
+				encode_getattr_maxsz + \
+				encode_renew_maxsz)
+#define NFS4_dec_gdd_getattr_sz	(compound_decode_hdr_maxsz + \
+				decode_sequence_maxsz + \
+				decode_putfh_maxsz + \
+				decode_get_dir_delegation_maxsz + \
+				decode_getattr_maxsz + \
+				decode_renew_maxsz)
 #define NFS4_enc_lookup_sz	(compound_encode_hdr_maxsz + \
 				encode_sequence_maxsz + \
 				encode_putfh_maxsz + \
@@ -1981,6 +2009,30 @@ static void encode_sequence(struct xdr_stream *xdr,
 }
 
 #ifdef CONFIG_NFS_V4_1
+static void
+encode_get_dir_delegation(struct xdr_stream *xdr, struct compound_hdr *hdr)
+{
+	__be32 *p;
+	struct timespec64 ts = {};
+	u32 zerobm[1] = {};
+
+	encode_op_hdr(xdr, OP_GET_DIR_DELEGATION, decode_get_dir_delegation_maxsz, hdr);
+
+	/* We can't handle CB_RECALLABLE_OBJ_AVAIL yet */
+	xdr_stream_encode_bool(xdr, false);
+
+	/* for now, we request no notification types */
+	xdr_encode_bitmap4(xdr, zerobm, ARRAY_SIZE(zerobm));
+
+	/* Request no attribute updates */
+	p = reserve_space(xdr, 12 + 12);
+	p = xdr_encode_nfstime4(p, &ts);
+	xdr_encode_nfstime4(p, &ts);
+
+	xdr_encode_bitmap4(xdr, zerobm, ARRAY_SIZE(zerobm));
+	xdr_encode_bitmap4(xdr, zerobm, ARRAY_SIZE(zerobm));
+}
+
 static void
 encode_getdeviceinfo(struct xdr_stream *xdr,
 		     const struct nfs4_getdeviceinfo_args *args,
@@ -2334,6 +2386,25 @@ static void nfs4_xdr_enc_getattr(struct rpc_rqst *req, struct xdr_stream *xdr,
 	encode_nops(&hdr);
 }
 
+/*
+ * Encode GDD_GETATTR request
+ */
+static void nfs4_xdr_enc_gdd_getattr(struct rpc_rqst *req, struct xdr_stream *xdr,
+				     const void *data)
+{
+	const struct nfs4_getattr_arg *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->fh, &hdr);
+	encode_get_dir_delegation(xdr, &hdr);
+	encode_getfattr(xdr, args->bitmask, &hdr);
+	encode_nops(&hdr);
+}
+
 /*
  * Encode a CLOSE request
  */
@@ -5919,6 +5990,43 @@ static int decode_layout_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
 	return decode_stateid(xdr, stateid);
 }
 
+static int decode_get_dir_delegation(struct xdr_stream *xdr,
+				     struct nfs4_getattr_res *res)
+{
+	nfs4_verifier	cookieverf;
+	int		status;
+	u32		bm[1];
+
+	status = decode_op_hdr(xdr, OP_GET_DIR_DELEGATION);
+	if (status)
+		return status;
+
+	if (xdr_stream_decode_u32(xdr, &res->nf_status))
+		return -EIO;
+
+	if (res->nf_status == GDD4_UNAVAIL)
+		return xdr_inline_decode(xdr, 4) ? 0 : -EIO;
+
+	status = decode_verifier(xdr, &cookieverf);
+	if (status)
+		return status;
+
+	status = decode_delegation_stateid(xdr, &res->deleg);
+	if (status)
+		return status;
+
+	status = decode_bitmap4(xdr, bm, ARRAY_SIZE(bm));
+	if (status < 0)
+		return status;
+	status = decode_bitmap4(xdr, bm, ARRAY_SIZE(bm));
+	if (status < 0)
+		return status;
+	status = decode_bitmap4(xdr, bm, ARRAY_SIZE(bm));
+	if (status < 0)
+		return status;
+	return 0;
+}
+
 static int decode_getdeviceinfo(struct xdr_stream *xdr,
 				struct nfs4_getdeviceinfo_res *res)
 {
@@ -6455,6 +6563,33 @@ static int nfs4_xdr_dec_getattr(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
 	return status;
 }
 
+/*
+ * Decode GDD_GETATTR response
+ */
+static int nfs4_xdr_dec_gdd_getattr(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
+				    void *data)
+{
+	struct nfs4_getattr_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_get_dir_delegation(xdr, res);
+	if (status)
+		goto out;
+	status = decode_getfattr(xdr, res->fattr, res->server);
+out:
+	return status;
+}
+
 /*
  * Encode an SETACL request
  */
@@ -7704,6 +7839,7 @@ const struct rpc_procinfo nfs4_procedures[] = {
 	PROC41(BIND_CONN_TO_SESSION,
 			enc_bind_conn_to_session, dec_bind_conn_to_session),
 	PROC41(DESTROY_CLIENTID,enc_destroy_clientid,	dec_destroy_clientid),
+	PROC41(GDD_GETATTR,	enc_gdd_getattr,	dec_gdd_getattr),
 	PROC42(SEEK,		enc_seek,		dec_seek),
 	PROC42(ALLOCATE,	enc_allocate,		dec_allocate),
 	PROC42(DEALLOCATE,	enc_deallocate,		dec_deallocate),
diff --git a/include/linux/nfs4.h b/include/linux/nfs4.h
index 11ad088b411d..86cbfd50ecd1 100644
--- a/include/linux/nfs4.h
+++ b/include/linux/nfs4.h
@@ -681,6 +681,7 @@ enum {
 	NFSPROC4_CLNT_LISTXATTRS,
 	NFSPROC4_CLNT_REMOVEXATTR,
 	NFSPROC4_CLNT_READ_PLUS,
+	NFSPROC4_CLNT_GDD_GETATTR,
 };
 
 /* nfs41 types */
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index d09b9773b20c..85ee37ccc25e 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -1072,6 +1072,8 @@ struct nfs4_getattr_res {
 	struct nfs4_sequence_res	seq_res;
 	const struct nfs_server *	server;
 	struct nfs_fattr *		fattr;
+	nfs4_stateid			deleg;
+	u32				nf_status;
 };
 
 struct nfs4_link_arg {

-- 
2.44.0