Btrfs: fix wrong return value of btrfs_lookup_csum()

If we don't find the expected csum item, but find a csum item which is
adjacent to the specified extent, we should return -EFBIG, or we should
return -ENOENT. But btrfs_lookup_csum() return -EFBIG even the csum item
is not adjacent to the specified extent. Fix it.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index b7e529d2860f2f42e3a826593359419a4e5f4111..c4628a201cb30fe6e2daa09eff83bd1fec79ecf1 100644 (file)
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -118,9 +118,11 @@ struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans,
                csums_in_item = btrfs_item_size_nr(leaf, path->slots[0]);
                csums_in_item /= csum_size;
 
-               if (csum_offset >= csums_in_item) {
+               if (csum_offset == csums_in_item) {
                        ret = -EFBIG;
                        goto fail;
+               } else if (csum_offset > csums_in_item) {
+                       goto fail;
                }
        }
        item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);