btrfs: convert some BUG_ON()'s to ASSERT()'s in do_relocation

A few of these are checking for correctness, and won't be triggered by
corrupted file systems, so convert them to ASSERT() instead of BUG_ON()
and add a comment explaining their existence.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index bf269ee..4d9b6f9 100644 (file)
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -2181,7 +2181,11 @@ static int do_relocation(struct btrfs_trans_handle *trans,
        int slot;
        int ret = 0;
 
-       BUG_ON(lowest && node->eb);
+       /*
+        * If we are lowest then this is the first time we're processing this
+        * block, and thus shouldn't have an eb associated with it yet.
+        */
+       ASSERT(!lowest || !node->eb);
 
        path->lowest_level = node->level + 1;
        rc->backref_cache.path[node->level] = node;
@@ -2266,7 +2270,11 @@ static int do_relocation(struct btrfs_trans_handle *trans,
                        free_extent_buffer(eb);
                        if (ret < 0)
                                goto next;
-                       BUG_ON(node->eb != eb);
+                       /*
+                        * We've just COWed this block, it should have updated
+                        * the correct backref node entry.
+                        */
+                       ASSERT(node->eb == eb);
                } else {
                        btrfs_set_node_blockptr(upper->eb, slot,
                                                node->eb->start);
@@ -2302,7 +2310,12 @@ next:
        }
 
        path->lowest_level = 0;
-       BUG_ON(ret == -ENOSPC);
+
+       /*
+        * We should have allocated all of our space in the block rsv and thus
+        * shouldn't ENOSPC.
+        */
+       ASSERT(ret != -ENOSPC);
        return ret;
 }