From: Josef Bacik <josef@toxicpanda.com>
Date: Wed, 4 Mar 2020 11:18:26 -0500
Git-commit: 1a0afa0ecfc4dbc8d7583d03cafd3f68f781df0c
Patch-mainline: 5.7-rc1
References: bsc#1176019
Subject: [PATCH] btrfs: free the reloc_control in a consistent way

If we have an error while processing the reloc roots we could leak roots
that were added to rc->reloc_roots before we hit the error.  We could
have also not removed the reloc tree mapping from our rb_tree, so clean
up any remaining nodes in the reloc root rb_tree.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ use rbtree_postorder_for_each_entry_safe ]
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
---
 fs/btrfs/relocation.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 631f94085ba6..a0c8f7949a19 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -4202,6 +4202,18 @@ static struct reloc_control *alloc_reloc_control(struct btrfs_fs_info *fs_info)
 	return rc;
 }
 
+static void free_reloc_control(struct reloc_control *rc)
+{
+	struct mapping_node *node, *tmp;
+
+	free_reloc_roots(&rc->reloc_roots);
+	rbtree_postorder_for_each_entry_safe(node, tmp,
+			&rc->reloc_root_tree.rb_root, rb_node)
+		kfree(node);
+
+	kfree(rc);
+}
+
 /*
  * Print the block group being relocated
  */
@@ -4346,7 +4358,7 @@ int btrfs_relocate_block_group(struct btrfs_fs_info *fs_info, u64 group_start)
 		btrfs_dec_block_group_ro(rc->block_group);
 	iput(rc->data_inode);
 	btrfs_put_block_group(rc->block_group);
-	kfree(rc);
+	free_reloc_control(rc);
 	return err;
 }
 
@@ -4522,7 +4534,7 @@ int btrfs_recover_relocation(struct btrfs_root *root)
 		err = ret;
 out_unset:
 	unset_reloc_control(rc);
-	kfree(rc);
+	free_reloc_control(rc);
 out:
 	if (!list_empty(&reloc_roots))
 		free_reloc_roots(&reloc_roots);
-- 
2.26.2