Btrfs: make sure the backref walker catches all refs to our extent

[karo-tx-linux.git] / fs / btrfs / backref.c

diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index 30dbe1c618577bcfd7c7f47f3403845d35b7ee91..8bc5e8ccb091852dd53f262eb556fe5578a419a3 100644 (file)
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -196,7 +196,7 @@ static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path,
        struct extent_buffer *eb;
        struct btrfs_key key;
        struct btrfs_file_extent_item *fi;
-       struct extent_inode_elem *eie = NULL;
+       struct extent_inode_elem *eie = NULL, *old = NULL;
        u64 disk_byte;
 
        if (level != 0) {
@@ -230,6 +230,7 @@ static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path,
 
                if (disk_byte == wanted_disk_byte) {
                        eie = NULL;
+                       old = NULL;
                        if (extent_item_pos) {
                                ret = check_extent_in_eb(&key, eb, fi,
                                                *extent_item_pos,
@@ -237,18 +238,20 @@ static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path,
                                if (ret < 0)
                                        break;
                        }
-                       if (!ret) {
-                               ret = ulist_add(parents, eb->start,
-                                               (uintptr_t)eie, GFP_NOFS);
-                               if (ret < 0)
-                                       break;
-                               if (!extent_item_pos) {
-                                       ret = btrfs_next_old_leaf(root, path,
-                                                       time_seq);
-                                       continue;
-                               }
+                       if (ret > 0)
+                               goto next;
+                       ret = ulist_add_merge(parents, eb->start,
+                                             (uintptr_t)eie,
+                                             (u64 *)&old, GFP_NOFS);
+                       if (ret < 0)
+                               break;
+                       if (!ret && extent_item_pos) {
+                               while (old->next)
+                                       old = old->next;
+                               old->next = eie;
                        }
                }
+next:
                ret = btrfs_next_old_item(root, path, time_seq);
        }