blob: 0782be9f43c4d8cd95174994c074da1f91d35ee5 [file] [log] [blame]
From aa8a1e69a36691c75a77297a0a873fe0f7a9ee9f Mon Sep 17 00:00:00 2001
From: Josef Bacik <>
Date: Wed, 4 Mar 2020 11:18:23 -0500
Subject: [PATCH] btrfs: drop block from cache on error in relocation
commit 8e19c9732ad1d127b5575a10f4fbcacf740500ff upstream.
If we have an error while building the backref tree in relocation we'll
process all the pending edges and then free the node. However if we
integrated some edges into the cache we'll lose our link to those edges
by simply freeing this node, which means we'll leak memory and
references to any roots that we've found.
Instead we need to use remove_backref_node(), which walks through all of
the edges that are still linked to this node and free's them up and
drops any root references we may be holding.
CC: # 4.9+
Reviewed-by: Qu Wenruo <>
Signed-off-by: Josef Bacik <>
Reviewed-by: David Sterba <>
Signed-off-by: David Sterba <>
Signed-off-by: Paul Gortmaker <>
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 95ff8f631d06..f3876884e714 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -1152,7 +1152,7 @@ struct backref_node *build_backref_tree(struct reloc_control *rc,
free_backref_node(cache, lower);
- free_backref_node(cache, node);
+ remove_backref_node(cache, node);
return ERR_PTR(err);
ASSERT(!node || !node->detached);