knfsd: set the response bitmask for NFS4_CREATE_EXCLUSIVE

RFC 3530 says:

 If the server uses an attribute to store the exclusive create verifier, it
 will signify which attribute by setting the appropriate bit in the attribute
 mask that is returned in the results.

Linux uses the atime and mtime to store the verifier, but sends a zeroed out
bitmask back to the client.  This patch makes sure that we set the correct
bits in the bitmask in this situation.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/nfsd/nfs4proc.c

@@ -100,7 +100,15 @@ do_open_lookup(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_o
 		status = nfsd_create_v3(rqstp, current_fh, open->op_fname.data,
 					open->op_fname.len, &open->op_iattr,
 					&resfh, open->op_createmode,
-					(u32 *)open->op_verf.data, &open->op_truncate, &created);
+					(u32 *)open->op_verf.data,
+					&open->op_truncate, &created);
+
+		/* If we ever decide to use different attrs to store the
+		 * verifier in nfsd_create_v3, then we'll need to change this
+		 */
+		if (open->op_createmode == NFS4_CREATE_EXCLUSIVE && status == 0)
+			open->op_bmval[1] |= (FATTR4_WORD1_TIME_ACCESS |
+						FATTR4_WORD1_TIME_MODIFY);
 	} else {
 		status = nfsd_lookup(rqstp, current_fh,
 				     open->op_fname.data, open->op_fname.len, &resfh);

fs/nfsd/vfs.c

@@ -1309,7 +1309,10 @@ nfsd_create_v3(struct svc_rqst *rqstp, struct svc_fh *fhp,
 
 	if (createmode == NFS3_CREATE_EXCLUSIVE) {
 		/* solaris7 gets confused (bugid 4218508) if these have
-		 * the high bit set, so just clear the high bits.
+		 * the high bit set, so just clear the high bits. If this is
+		 * ever changed to use different attrs for storing the
+		 * verifier, then do_open_lookup() will also need to be fixed
+		 * accordingly.
 		 */
 		v_mtime = verifier[0]&0x7fffffff;
 		v_atime = verifier[1]&0x7fffffff;