@@ -2209,7 +2209,13 @@ struct btrfs_root *select_one_root(struct btrfs_backref_node *node)
cond_resched();
next = walk_up_backref(next, edges, &index);
root = next->root;
- BUG_ON(!root);
+
+ /*
+ * This can occur if we have incomplete extent refs leading all
+ * the way up a particular path, in this case return -EUCLEAN.
+ */
+ if (!root)
+ return ERR_PTR(-EUCLEAN);
/* No other choice for non-shareable tree */
if (!test_bit(BTRFS_ROOT_SHAREABLE, &root->state))
@@ -2599,8 +2605,15 @@ static int relocate_tree_block(struct btrfs_trans_handle *trans,
BUG_ON(node->processed);
root = select_one_root(node);
- if (root == ERR_PTR(-ENOENT)) {
- update_processed_blocks(rc, node);
+ if (IS_ERR(root)) {
+ ret = PTR_ERR(root);
+
+ /* See explanation in select_one_root for the -EUCLEAN case. */
+ ASSERT(ret == -ENOENT);
+ if (ret == -ENOENT) {
+ ret = 0;
+ update_processed_blocks(rc, node);
+ }
goto out;
}
In corruption cases we could have paths from a block up to no root at all, and thus we'll BUG_ON(!root) in select_one_root. Handle this by adding an ASSERT() for developers, and returning an error for normal users. Signed-off-by: Josef Bacik <josef@toxicpanda.com> --- fs/btrfs/relocation.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-)