pnfsblock: call and parse getdevicelist

Call GETDEVICELIST during mount, then call and parse GETDEVICEINFO
for each device returned.

[pnfsblock: get rid of deprecated xdr macros]
Signed-off-by: Jim Rees <rees@umich.edu>
[pnfsblock: fix pnfs_deviceid references]
Signed-off-by: Fred Isaman <iisaman@citi.umich.edu>
[pnfsblock: fix print format warnings for sector_t and size_t]
[pnfs-block: #include <linux/vmalloc.h>]
[pnfsblock: no PNFS_NFS_SERVER]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[pnfsblock: fix bug determining size of striped volume]
[pnfsblock: fix oops when using multiple devices]
Signed-off-by: Fred Isaman <iisaman@citi.umich.edu>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Benny Halevy <bhalevy@tonian.com>
[pnfsblock: get rid of vmap and deviceid->area structure]
Signed-off-by: Peng Tao <peng_tao@emc.com>
Signed-off-by: Jim Rees <rees@umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index b2ea8b8..cc03fc1 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -146,6 +146,7 @@
 	struct pnfs_layoutdriver_type  *pnfs_curr_ld; /* Active layout driver */
 	struct rpc_wait_queue	roc_rpcwaitq;
 	u32			pnfs_blksize;	/* layout_blksize attr */
+	void			*pnfs_ld_data;	/* per mount point data */
 
 	/* the following fields are protected by nfs_client->cl_lock */
 	struct rb_root		state_owners;