Btrfs: Fix "no csum found for inode" issue.

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>

1 files changed, 3 insertions, 2 deletions

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index fcae999ab712..9262ab37a7cd 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2417,12 +2417,13 @@ int try_release_extent_mapping(struct extent_map_tree *map,
         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;