[Ocfs2-devel] [patch 1/4] ocfs2: fix a couple of memory leaks at o2hb_map_slot_data()

[Joseph Qi]

These memory will be freed in o2hb_region_release. If we free them here,
then it will lead to double freed issue.

> This patch can fix a couple of potential memory leaks at
> o2hb_map_slot_data().
> 
> Signed-off-by: Jie Liu <jeff.liu at oracle.com>
> 
> ---
>  fs/ocfs2/cluster/heartbeat.c |   33 +++++++++++++++++++++++++--------
>  1 files changed, 25 insertions(+), 8 deletions(-)
> 
> diff --git a/fs/ocfs2/cluster/heartbeat.c b/fs/ocfs2/cluster/heartbeat.c
> index a4e855e..1b6ce53 100644
> --- a/fs/ocfs2/cluster/heartbeat.c
> +++ b/fs/ocfs2/cluster/heartbeat.c
> @@ -1638,7 +1638,7 @@ static void o2hb_init_region_params(struct
> o2hb_region *reg)
> 
>  static int o2hb_map_slot_data(struct o2hb_region *reg)
>  {
> -	int i, j;
> +	int ret = 0, i, j;
>  	unsigned int last_slot;
>  	unsigned int spp = reg->hr_slots_per_page;
>  	struct page *page;
> @@ -1654,8 +1654,8 @@ static int o2hb_map_slot_data(struct o2hb_region *reg)
>  	reg->hr_slots = kcalloc(reg->hr_blocks,
>  				sizeof(struct o2hb_disk_slot), GFP_KERNEL);
>  	if (reg->hr_slots == NULL) {
> -		mlog_errno(-ENOMEM);
> -		return -ENOMEM;
> +		ret = -ENOMEM;
> +		goto free;
>  	}
> 
>  	for(i = 0; i < reg->hr_blocks; i++) {
> @@ -1673,15 +1673,15 @@ static int o2hb_map_slot_data(struct o2hb_region
> *reg)
>  	reg->hr_slot_data = kcalloc(reg->hr_num_pages, sizeof(struct page *),
>  				    GFP_KERNEL);
>  	if (!reg->hr_slot_data) {
> -		mlog_errno(-ENOMEM);
> -		return -ENOMEM;
> +		ret = -ENOMEM;
> +		goto free;
>  	}
> 
>  	for(i = 0; i < reg->hr_num_pages; i++) {
>  		page = alloc_page(GFP_KERNEL);
>  		if (!page) {
> -			mlog_errno(-ENOMEM);
> -			return -ENOMEM;
> +			ret = -ENOMEM;
> +			goto free;
>  		}
> 
>  		reg->hr_slot_data[i] = page;
> @@ -1701,7 +1701,24 @@ static int o2hb_map_slot_data(struct o2hb_region
> *reg)
>  		}
>  	}
> 
> -	return 0;
> +	return ret;
> +
> +free:
> +	mlog_errno(ret);
> +
> +	kfree(reg->hr_tmp_block);
> +	kfree(reg->hr_slots);
> +
> +	if (reg->hr_slot_data) {
> +		for (i = 0; i < reg->hr_num_pages; i++) {
> +			page = reg->hr_slot_data[i];
> +			if (page)
> +				__free_page(reg->hr_slot_data[i]);
> +		}
> +		kfree(reg->hr_slot_data);
> +	}
> +
> +	return ret;
>  }
> 
>  /* Read in all the slots available and populate the tracking
>