nfsd: trivial GET_DIR_DELEGATION support

This adds basic infrastructure for handing GET_DIR_DELEGATION calls from
clients, including the decoders and encoders. For now, it always just
returns NFS4_OK + GDD4_UNAVAIL.

Eventually clients may start sending this operation, and it's better if
we can return GDD4_UNAVAIL instead of having to abort the whole compound.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

1 files changed, 74 insertions, 2 deletions

diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index a644460f3a5e..ea76100e50ca 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -1732,6 +1732,35 @@ nfsd4_decode_free_stateid(struct nfsd4_compoundargs *argp,
 	return nfsd4_decode_stateid4(argp, &free_stateid->fr_stateid);
 }
 
+static __be32
+nfsd4_decode_get_dir_delegation(struct nfsd4_compoundargs *argp,
+		union nfsd4_op_u *u)
+{
+	struct nfsd4_get_dir_delegation *gdd = &u->get_dir_delegation;
+	__be32 status;
+
+	memset(gdd, 0, sizeof(*gdd));
+
+	if (xdr_stream_decode_bool(argp->xdr, &gdd->gdda_signal_deleg_avail) < 0)
+		return nfserr_bad_xdr;
+	status = nfsd4_decode_bitmap4(argp, gdd->gdda_notification_types,
+				      ARRAY_SIZE(gdd->gdda_notification_types));
+	if (status)
+		return status;
+	status = nfsd4_decode_nfstime4(argp, &gdd->gdda_child_attr_delay);
+	if (status)
+		return status;
+	status = nfsd4_decode_nfstime4(argp, &gdd->gdda_dir_attr_delay);
+	if (status)
+		return status;
+	status = nfsd4_decode_bitmap4(argp, gdd->gdda_child_attributes,
+					ARRAY_SIZE(gdd->gdda_child_attributes));
+	if (status)
+		return status;
+	return nfsd4_decode_bitmap4(argp, gdd->gdda_dir_attributes,
+					ARRAY_SIZE(gdd->gdda_dir_attributes));
+}
+
 #ifdef CONFIG_NFSD_PNFS
 static __be32
 nfsd4_decode_getdeviceinfo(struct nfsd4_compoundargs *argp,
@@ -2370,7 +2399,7 @@ static const nfsd4_dec nfsd4_dec_ops[] = {
 	[OP_CREATE_SESSION]	= nfsd4_decode_create_session,
 	[OP_DESTROY_SESSION]	= nfsd4_decode_destroy_session,
 	[OP_FREE_STATEID]	= nfsd4_decode_free_stateid,
-	[OP_GET_DIR_DELEGATION]	= nfsd4_decode_notsupp,
+	[OP_GET_DIR_DELEGATION]	= nfsd4_decode_get_dir_delegation,
 #ifdef CONFIG_NFSD_PNFS
 	[OP_GETDEVICEINFO]	= nfsd4_decode_getdeviceinfo,
 	[OP_GETDEVICELIST]	= nfsd4_decode_notsupp,
@@ -4963,6 +4992,49 @@ nfsd4_encode_test_stateid(struct nfsd4_compoundres *resp, __be32 nfserr,
 	return nfs_ok;
 }
 
+static __be32
+nfsd4_encode_get_dir_delegation(struct nfsd4_compoundres *resp, __be32 nfserr,
+				union nfsd4_op_u *u)
+{
+	struct nfsd4_get_dir_delegation *gdd = &u->get_dir_delegation;
+	struct xdr_stream *xdr = resp->xdr;
+	__be32 status = nfserr_resource;
+
+	switch(gdd->gddrnf_status) {
+	case GDD4_OK:
+		if (xdr_stream_encode_u32(xdr, GDD4_OK) != XDR_UNIT)
+			break;
+		status = nfsd4_encode_verifier4(xdr, &gdd->gddr_cookieverf);
+		if (status)
+			break;
+		status = nfsd4_encode_stateid4(xdr, &gdd->gddr_stateid);
+		if (status)
+			break;
+		status = nfsd4_encode_bitmap4(xdr, gdd->gddr_notification[0], 0, 0);
+		if (status)
+			break;
+		status = nfsd4_encode_bitmap4(xdr, gdd->gddr_child_attributes[0],
+						   gdd->gddr_child_attributes[1],
+						   gdd->gddr_child_attributes[2]);
+		if (status)
+			break;
+		status = nfsd4_encode_bitmap4(xdr, gdd->gddr_dir_attributes[0],
+						   gdd->gddr_dir_attributes[1],
+						   gdd->gddr_dir_attributes[2]);
+		break;
+	default:
+		pr_warn("nfsd: bad gddrnf_status (%u)\n", gdd->gddrnf_status);
+		gdd->gddrnf_will_signal_deleg_avail = 0;
+		fallthrough;
+	case GDD4_UNAVAIL:
+		if (xdr_stream_encode_u32(xdr, GDD4_UNAVAIL) != XDR_UNIT)
+			break;
+		status = nfsd4_encode_bool(xdr, gdd->gddrnf_will_signal_deleg_avail);
+		break;
+	}
+	return status;
+}
+
 #ifdef CONFIG_NFSD_PNFS
 static __be32
 nfsd4_encode_device_addr4(struct xdr_stream *xdr,
@@ -5579,7 +5651,7 @@ static const nfsd4_enc nfsd4_enc_ops[] = {
 	[OP_CREATE_SESSION]	= nfsd4_encode_create_session,
 	[OP_DESTROY_SESSION]	= nfsd4_encode_noop,
 	[OP_FREE_STATEID]	= nfsd4_encode_noop,
-	[OP_GET_DIR_DELEGATION]	= nfsd4_encode_noop,
+	[OP_GET_DIR_DELEGATION]	= nfsd4_encode_get_dir_delegation,
 #ifdef CONFIG_NFSD_PNFS
 	[OP_GETDEVICEINFO]	= nfsd4_encode_getdeviceinfo,
 	[OP_GETDEVICELIST]	= nfsd4_encode_noop,