Re: [PATCH] btrfs: fix a memory leak issue in read_one_chunk()

[Qu Wenruo <quwenruo.btrfs@gmx.com>]

在 2025/3/3 13:12, Haoxiang Li 写道:
> Add btrfs_free_chunk_map() to free the memory allocated
> by btrfs_alloc_chunk_map() if btrfs_add_chunk_map() fails.
>
> Fixes: 7dc66abb5a47 ("btrfs: use a dedicated data structure for chunk maps")
> Cc: stable@vger.kernel.org
> Signed-off-by: Haoxiang Li <haoxiang_li2024@163.com>

Reviewed-by: Qu Wenruo <wqu@suse.com>

And the fixes tag is also correct, before that commit, add_extent_map()
will increase the ref if tree_insert() succeeded, thus if it failed the
unconditional free_extent_map() will just free the no longer utilized em.

But at that commit, we no longer has that feature, thus has to manually
cleanup the map.

Thanks,
Qu

> ---
>   fs/btrfs/volumes.c | 1 +
>   1 file changed, 1 insertion(+)
>
> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
> index fb22d4425cb0..3f8afbd1ebb5 100644
> --- a/fs/btrfs/volumes.c
> +++ b/fs/btrfs/volumes.c
> @@ -7155,6 +7155,7 @@ static int read_one_chunk(struct btrfs_key *key, struct extent_buffer *leaf,
>   		btrfs_err(fs_info,
>   			  "failed to add chunk map, start=%llu len=%llu: %d",
>   			  map->start, map->chunk_len, ret);
> +		btrfs_free_chunk_map(map);
>   	}
>
>   	return ret;