NFSD: Replace READ* macros that decode the fattr4 time_set attributes

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

fs/nfsd/nfs4xdr.c

@@ -219,6 +219,21 @@ nfsd4_decode_time(struct nfsd4_compoundargs *argp, struct timespec64 *tv)
 	DECODE_TAIL;
 }
 
+static __be32
+nfsd4_decode_nfstime4(struct nfsd4_compoundargs *argp, struct timespec64 *tv)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(argp->xdr, XDR_UNIT * 3);
+	if (!p)
+		return nfserr_bad_xdr;
+	p = xdr_decode_hyper(p, &tv->tv_sec);
+	tv->tv_nsec = be32_to_cpup(p++);
+	if (tv->tv_nsec >= (u32)1000000000)
+		return nfserr_inval;
+	return nfs_ok;
+}
+
 static __be32
 nfsd4_decode_bitmap(struct nfsd4_compoundargs *argp, u32 *bmval)
 {
@@ -388,11 +403,13 @@ nfsd4_decode_fattr(struct nfsd4_compoundargs *argp, u32 *bmval,
 		iattr->ia_valid |= ATTR_GID;
 	}
 	if (bmval[1] & FATTR4_WORD1_TIME_ACCESS_SET) {
-		READ_BUF(4);
-		dummy32 = be32_to_cpup(p++);
-		switch (dummy32) {
+		u32 set_it;
+
+		if (xdr_stream_decode_u32(argp->xdr, &set_it) < 0)
+			return nfserr_bad_xdr;
+		switch (set_it) {
 		case NFS4_SET_TO_CLIENT_TIME:
-			status = nfsd4_decode_time(argp, &iattr->ia_atime);
+			status = nfsd4_decode_nfstime4(argp, &iattr->ia_atime);
 			if (status)
 				return status;
 			iattr->ia_valid |= (ATTR_ATIME | ATTR_ATIME_SET);
@@ -401,15 +418,17 @@ nfsd4_decode_fattr(struct nfsd4_compoundargs *argp, u32 *bmval,
 			iattr->ia_valid |= ATTR_ATIME;
 			break;
 		default:
-			goto xdr_error;
+			return nfserr_bad_xdr;
 		}
 	}
 	if (bmval[1] & FATTR4_WORD1_TIME_MODIFY_SET) {
-		READ_BUF(4);
-		dummy32 = be32_to_cpup(p++);
-		switch (dummy32) {
+		u32 set_it;
+
+		if (xdr_stream_decode_u32(argp->xdr, &set_it) < 0)
+			return nfserr_bad_xdr;
+		switch (set_it) {
 		case NFS4_SET_TO_CLIENT_TIME:
-			status = nfsd4_decode_time(argp, &iattr->ia_mtime);
+			status = nfsd4_decode_nfstime4(argp, &iattr->ia_mtime);
 			if (status)
 				return status;
 			iattr->ia_valid |= (ATTR_MTIME | ATTR_MTIME_SET);
@@ -418,7 +437,7 @@ nfsd4_decode_fattr(struct nfsd4_compoundargs *argp, u32 *bmval,
 			iattr->ia_valid |= ATTR_MTIME;
 			break;
 		default:
-			goto xdr_error;
+			return nfserr_bad_xdr;
 		}
 	}