nfsd41: SUPPATTR_EXCLCREAT attribute

Return bitmask for supported EXCLUSIVE4_1 create attributes.
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

fs/nfsd/nfs4xdr.c

@@ -2148,7 +2148,12 @@ nfsd4_encode_fattr(struct svc_fh *fhp, struct svc_export *exp,
 		}
 		WRITE64(stat.ino);
 	}
-	BUG_ON(bmval2);	/* FIXME: not implemented yet */
+	if (bmval2 & FATTR4_WORD2_SUPPATTR_EXCLCREAT) {
+		WRITE32(3);
+		WRITE32(NFSD_SUPPATTR_EXCLCREAT_WORD0);
+		WRITE32(NFSD_SUPPATTR_EXCLCREAT_WORD1);
+		WRITE32(NFSD_SUPPATTR_EXCLCREAT_WORD2);
+	}
 
 	*attrlenp = htonl((char *)p - (char *)attrlenp - 4);
 	*countp = p - buffer;

include/linux/nfs4.h

@@ -404,6 +404,8 @@ enum lock_type4 {
 #define FATTR4_WORD0_UNIQUE_HANDLES     (1UL << 9)
 #define FATTR4_WORD0_LEASE_TIME         (1UL << 10)
 #define FATTR4_WORD0_RDATTR_ERROR       (1UL << 11)
+/* Mandatory in NFSv4.1 */
+#define FATTR4_WORD2_SUPPATTR_EXCLCREAT (1UL << 11)
 
 /* Recommended Attributes */
 #define FATTR4_WORD0_ACL                (1UL << 12)

include/linux/nfsd/nfsd.h

@@ -375,7 +375,7 @@ extern struct timeval	nfssvc_boot;
 	NFSD4_SUPPORTED_ATTRS_WORD1
 
 #define NFSD4_1_SUPPORTED_ATTRS_WORD2 \
-	NFSD4_SUPPORTED_ATTRS_WORD2
+	(NFSD4_SUPPORTED_ATTRS_WORD2 | FATTR4_WORD2_SUPPATTR_EXCLCREAT)
 
 static inline u32 nfsd_suppattrs0(u32 minorversion)
 {
@@ -407,6 +407,18 @@ static inline u32 nfsd_suppattrs2(u32 minorversion)
  | FATTR4_WORD1_TIME_ACCESS_SET | FATTR4_WORD1_TIME_MODIFY_SET)
 #define NFSD_WRITEABLE_ATTRS_WORD2 0
 
+#define NFSD_SUPPATTR_EXCLCREAT_WORD0 \
+	NFSD_WRITEABLE_ATTRS_WORD0
+/*
+ * we currently store the exclusive create verifier in the v_{a,m}time
+ * attributes so the client can't set these at create time using EXCLUSIVE4_1
+ */
+#define NFSD_SUPPATTR_EXCLCREAT_WORD1 \
+	(NFSD_WRITEABLE_ATTRS_WORD1 & \
+	 ~(FATTR4_WORD1_TIME_ACCESS_SET | FATTR4_WORD1_TIME_MODIFY_SET))
+#define NFSD_SUPPATTR_EXCLCREAT_WORD2 \
+	NFSD_WRITEABLE_ATTRS_WORD2
+
 #endif /* CONFIG_NFSD_V4 */
 
 #endif /* LINUX_NFSD_NFSD_H */