Allow SETATTR to handle delegated timestamps. This patch assumes that
only the delegation holder has the ability to set the timestamps in this
way, so we allow this only if the SETATTR stateid refers to a
*_ATTRS_DELEG delegation.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
 fs/nfsd/nfs4proc.c | 26 +++++++++++++++++++++++---
 fs/nfsd/nfs4xdr.c  | 20 ++++++++++++++++++++
 2 files changed, 43 insertions(+), 3 deletions(-)

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index fcce1f2e5454b0f3c4aa4b85fb4a4e24b2dee932..320c4f79662e65848dc824885566d48e696fe97c 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1133,18 +1133,38 @@ nfsd4_setattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 		.na_iattr	= &setattr->sa_iattr,
 		.na_seclabel	= &setattr->sa_label,
 	};
+	bool save_no_wcc, deleg_attrs;
+	struct nfs4_stid *st = NULL;
 	struct inode *inode;
 	__be32 status = nfs_ok;
-	bool save_no_wcc;
 	int err;
 
-	if (setattr->sa_iattr.ia_valid & ATTR_SIZE) {
+	deleg_attrs = setattr->sa_bmval[2] & (FATTR4_WORD2_TIME_DELEG_ACCESS |
+					      FATTR4_WORD2_TIME_DELEG_MODIFY);
+
+	if (deleg_attrs || (setattr->sa_iattr.ia_valid & ATTR_SIZE)) {
 		status = nfs4_preprocess_stateid_op(rqstp, cstate,
 				&cstate->current_fh, &setattr->sa_stateid,
-				WR_STATE, NULL, NULL);
+				WR_STATE, NULL, &st);
 		if (status)
 			return status;
 	}
+
+	if (deleg_attrs) {
+		status = nfserr_bad_stateid;
+		if (st->sc_type & SC_TYPE_DELEG) {
+			struct nfs4_delegation *dp = delegstateid(st);
+
+			/* Only for *_ATTRS_DELEG flavors */
+			if (deleg_attrs_deleg(dp->dl_type))
+				status = nfs_ok;
+		}
+	}
+	if (st)
+		nfs4_put_stid(st);
+	if (status)
+		return status;
+
 	err = fh_want_write(&cstate->current_fh);
 	if (err)
 		return nfserrno(err);
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 0e9f59f6be015bfa37893973f38fec880ff4c0b1..857b39fcdb772585601f760705564968bb0d554c 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -521,6 +521,26 @@ nfsd4_decode_fattr4(struct nfsd4_compoundargs *argp, u32 *bmval, u32 bmlen,
 		*umask = mask & S_IRWXUGO;
 		iattr->ia_valid |= ATTR_MODE;
 	}
+	if (bmval[2] & FATTR4_WORD2_TIME_DELEG_ACCESS) {
+		fattr4_time_deleg_access access;
+
+		if (!xdrgen_decode_fattr4_time_deleg_access(argp->xdr, &access))
+			return nfserr_bad_xdr;
+		iattr->ia_atime.tv_sec = access.seconds;
+		iattr->ia_atime.tv_nsec = access.nseconds;
+		iattr->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET | ATTR_DELEG;
+	}
+	if (bmval[2] & FATTR4_WORD2_TIME_DELEG_MODIFY) {
+		fattr4_time_deleg_modify modify;
+
+		if (!xdrgen_decode_fattr4_time_deleg_modify(argp->xdr, &modify))
+			return nfserr_bad_xdr;
+		iattr->ia_mtime.tv_sec = modify.seconds;
+		iattr->ia_mtime.tv_nsec = modify.nseconds;
+		iattr->ia_ctime.tv_sec = modify.seconds;
+		iattr->ia_ctime.tv_nsec = modify.seconds;
+		iattr->ia_valid |= ATTR_CTIME | ATTR_MTIME | ATTR_MTIME_SET | ATTR_DELEG;
+	}
 
 	/* request sanity: did attrlist4 contain the expected number of words? */
 	if (attrlist4_count != xdr_stream_pos(argp->xdr) - starting_pos)

-- 
2.47.0