A few codes were not properly updated for changes of extent map.  This
may be the causes of "no csum found for inode" issue.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
        u64 end = start + PAGE_CACHE_SIZE - 1;
        u64 orig_start = start;
        int ret = 1;
-
        if ((mask & __GFP_WAIT) &&
            page->mapping->host->i_size > 16 * 1024 * 1024) {
+               u64 len;
                while (start <= end) {
+                       len = end - start + 1;
                        spin_lock(&map->lock);
-                       em = lookup_extent_mapping(map, start, end);
+                       em = lookup_extent_mapping(map, start, len);
                        if (!em || IS_ERR(em)) {
                                spin_unlock(&map->lock);
                                break;
 
 {
        struct extent_map *em;
        struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
+       u64 len = end - start + 1;
 
+       if (end == (u64)-1)
+               len = (u64)-1;
        while(1) {
                spin_lock(&em_tree->lock);
-               em = lookup_extent_mapping(em_tree, start, end);
+               em = lookup_extent_mapping(em_tree, start, len);
                if (!em) {
                        spin_unlock(&em_tree->lock);
                        break;