We have a BUG_ON() if we get an error back from btrfs_get_fs_root().
This honestly should never fail, as at this point we have a solid
coordination of fs root to reloc root, and these roots will all be in
memory. But in the name of killing BUG_ON()'s remove these and handle
the error condition properly, ASSERT()'ing for developers.
Signed-off-by: Josef Bacik <jo...@toxicpanda.com>
---
fs/btrfs/relocation.c | 25 +++++++++++++++++++++++--
1 file changed, 23 insertions(+), 2 deletions(-)
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 621c4284d158..557d4f09ce7f 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -1960,8 +1960,29 @@ void merge_reloc_roots(struct reloc_control *rc)
root = btrfs_get_fs_root(fs_info, reloc_root->root_key.offset,
false);
if (btrfs_root_refs(&reloc_root->root_item) > 0) {
- BUG_ON(IS_ERR(root));
- BUG_ON(root->reloc_root != reloc_root);
+ if (IS_ERR(root)) {
+ /*
+ * For recovery we read the fs roots on mount,
+ * and if we didn't find the root then we marked
+ * the reloc root as a garbage root. For normal
+ * relocation obviously the root should exist in
+ * memory. However there's no reason we can't
+ * handle the error properly here just in case.
+ */
+ ASSERT(0);
+ ret = PTR_ERR(root);
+ goto out;
+ }
+ if (root->reloc_root != reloc_root) {
+ /*
+ * This is actually impossible without something
+ * going really wrong (like weird race condition
+ * or cosmic rays).
+ */
+ ASSERT(0);
+ ret = -EINVAL;
+ goto out;
+ }
ret = merge_reloc_root(rc, root);
btrfs_put_root(root);
if (ret) {
--
2.26.2
