pnfs: ask for layout_blksize and save it in nfs_server

Block layout needs it to determine IO size.

Signed-off-by: Fred Isaman <iisaman@citi.umich.edu>
Signed-off-by: Tao Guo <glorioustao@gmail.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Benny Halevy <bhalevy@tonian.com>
Signed-off-by: Jim Rees <rees@umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 21f333e..94f27e5 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -122,6 +122,7 @@
 	struct timespec		time_delta; /* server time granularity */
 	__u32			lease_time; /* in seconds */
 	__u32			layouttype; /* supported pnfs layout driver */
+	__u32			blksize; /* preferred pnfs io block size */
 };
 
 struct nfs_fsstat {
@@ -954,7 +955,7 @@
 };
 
 struct nfs4_server_caps_res {
-	u32				attr_bitmask[2];
+	u32				attr_bitmask[3];
 	u32				acl_bitmask;
 	u32				has_links;
 	u32				has_symlinks;