2 files changed, 31 insertions, 3 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index ab36769c356c..280ac1aa9b6d 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -1151,6 +1151,14 @@ int btrfs_cache_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                 }
 
                 ret = btrfs_add_leaf_ref(root, ref, shared);
+                if (ret == -EEXIST && shared) {
+                        struct btrfs_leaf_ref *old;
+                        old = btrfs_lookup_leaf_ref(root, ref->bytenr);
+                        BUG_ON(!old);
+                        btrfs_remove_leaf_ref(root, old);
+                        btrfs_free_leaf_ref(root, old);
+                        ret = btrfs_add_leaf_ref(root, ref, shared);
+                }
                 WARN_ON(ret);
                 btrfs_free_leaf_ref(root, ref);
         }
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 3ab147dc3c05..11bfe131fde6 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -48,6 +48,7 @@
 #include "xattr.h"
 #include "compat.h"
 #include "tree-log.h"
+#include "ref-cache.h"
 
 struct btrfs_iget_args {
         u64 ino;
@@ -1416,6 +1417,9 @@ static noinline int drop_csum_leaves(struct btrfs_trans_handle *trans,
         int nritems;
         struct btrfs_key found_key;
         struct btrfs_key other_key;
+        struct btrfs_leaf_ref *ref;
+        u64 leaf_gen;
+        u64 leaf_start;
 
         path->lowest_level = 1;
         key.objectid = inode->i_ino;
@@ -1509,15 +1513,31 @@ next_node:
         if (other_key.objectid != inode->i_ino || other_key.type != key.type)
                 goto out;
 
+        leaf_start = btrfs_node_blockptr(path->nodes[1], path->slots[1]);
+        leaf_gen = btrfs_node_ptr_generation(path->nodes[1], path->slots[1]);
         /*
          * it is safe to delete this leaf, it contains only
          * csum items from this inode at an offset >= new_size
          */
-        ret = btrfs_del_leaf(trans, root, path,
-                             btrfs_node_blockptr(path->nodes[1],
-                                                 path->slots[1]));
+        ret = btrfs_del_leaf(trans, root, path, leaf_start);
         BUG_ON(ret);
 
+        if (root->ref_cows && leaf_gen < trans->transid) {
+                ref = btrfs_alloc_leaf_ref(root, 0);
+                if (ref) {
+                        ref->root_gen = root->root_key.offset;
+                        ref->bytenr = leaf_start;
+                        ref->owner = 0;
+                        ref->generation = leaf_gen;
+                        ref->nritems = 0;
+
+                        ret = btrfs_add_leaf_ref(root, ref, 0);
+                        WARN_ON(ret);
+                        btrfs_free_leaf_ref(root, ref);
+                } else {
+                        WARN_ON(1);
+                }
+        }
 next_key:
         btrfs_release_path(root, path);