Btrfs: Fix compressed writes on truncated pages

The compression code was using isize to limit the amount of data it
sent through zlib.  But, it wasn't properly limiting the looping to
just the pages inside i_size.  The end result was trying to compress
too many pages, including those that had not been setup and properly locked
down.  This made the compression code oops while trying find_get_page on a
page that didn't exist.

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index c0c95cccbb5b..f6f7a6af0357 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -2887,8 +2887,8 @@ int btrfs_split_item(struct btrfs_trans_handle *trans,
         path->keep_locks = 0;
         BUG_ON(ret);
 
-        BUG_ON(btrfs_leaf_free_space(root, leaf) < sizeof(struct btrfs_item));
         leaf = path->nodes[0];
+        BUG_ON(btrfs_leaf_free_space(root, leaf) < sizeof(struct btrfs_item));
 
 split:
         item = btrfs_item_nr(leaf, path->slots[0]);