@@ -374,27 +374,35 @@ bool btrfs_block_can_be_shared(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *buf)
{
+ const u64 buf_gen = btrfs_header_generation(buf);
+
/*
* Tree blocks not in shareable trees and tree roots are never shared.
* If a block was allocated after the last snapshot and the block was
* not allocated by tree relocation, we know the block is not shared.
*/
- if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state) &&
- buf != root->node &&
- (btrfs_header_generation(buf) <=
- btrfs_root_last_snapshot(&root->root_item) ||
- btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC))) {
- if (buf != root->commit_root)
- return true;
- /*
- * An extent buffer that used to be the commit root may still be
- * shared because the tree height may have increased and it
- * became a child of a higher level root. This can happen when
- * snapshoting a subvolume created in the current transaction.
- */
- if (btrfs_header_generation(buf) == trans->transid)
- return true;
- }
+
+ if (!test_bit(BTRFS_ROOT_SHAREABLE, &root->state))
+ return false;
+
+ if (buf == root->node)
+ return false;
+
+ if (buf_gen > btrfs_root_last_snapshot(&root->root_item) &&
+ !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC))
+ return false;
+
+ if (buf != root->commit_root)
+ return true;
+
+ /*
+ * An extent buffer that used to be the commit root may still be shared
+ * because the tree height may have increased and it became a child of a
+ * higher level root. This can happen when snapshoting a subvolume
+ * created in the current transaction.
+ */
+ if (buf_gen == trans->transid)
+ return true;
return false;
}