NFS: Fix an infinite loop when layoutget fail with BAD_STATEID

If layouget fail with BAD_STATEID, restart should not using the old stateid.
But, nfs client choose the layout stateid at first, and then the open stateid.

To avoid the infinite loop of using bad stateid for layoutget,
this patch sets the layout flag'ss NFS_LAYOUT_INVALID_STID bit to
skip choosing the bad layout stateid.
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

fs/nfs/nfs4proc.c

@@ -7820,6 +7820,7 @@ static void nfs4_layoutget_done(struct rpc_task *task, void *calldata)
 			 * Mark the bad layout state as invalid, then retry
 			 * with the current stateid.
 			 */
+			set_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
 			pnfs_mark_matching_lsegs_invalid(lo, &head, NULL);
 			spin_unlock(&inode->i_lock);
 			pnfs_free_lseg_list(&head);