[PATCH 4/8] btrfs: free the reloc_control in a consistent way

Josef Bacik
2020-03-04T16:18:43Z

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 reloct 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>
---
fs/btrfs/relocation.c | 18 ++++++++++++++++--
1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index c496f8ed8c7e..f6237d885fe0 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -4387,6 +4387,20 @@ 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 rb_node *rb_node;
+ struct mapping_node *node;
+
+ free_reloc_roots(&rc->reloc_roots);
+ while ((rb_node = rb_first(&rc->reloc_root_tree.rb_root))) {
+ node = rb_entry(rb_node, struct mapping_node, rb_node);
+ rb_erase(rb_node, &rc->reloc_root_tree.rb_root);
+ kfree(node);
+ }
+ kfree(rc);
+}
+
/*
* Print the block group being relocated
*/
@@ -4531,7 +4545,7 @@ 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;
}

@@ -4708,7 +4722,7 @@ int btrfs_recover_relocation(struct btrfs_root *root)
out_unset:
unset_reloc_control(rc);
out_free:
- kfree(rc);
+ free_reloc_control(rc);
out:
if (!list_empty(&reloc_roots))
free_reloc_roots(&reloc_roots);
--
2.24.1