[CRIU] [PATCHv0 4/4] files-reg: move remaps unlink code into single function

[Pavel Emelyanov]

On 06/24/2016 11:38 PM, Eugene Batalov wrote:
> Signed-off-by: Eugene Batalov <eabatalov89 at gmail.com>
> ---
>  criu/files-reg.c | 34 +++++++++++++++++++++++-----------
>  1 file changed, 23 insertions(+), 11 deletions(-)
> 
> diff --git a/criu/files-reg.c b/criu/files-reg.c
> index 2f1c695..2b6a876 100644
> --- a/criu/files-reg.c
> +++ b/criu/files-reg.c
> @@ -522,6 +522,26 @@ static void try_clean_ghost(struct remap_info *ri)
>  	pr_perror(" `- XFail [%s] ghost", path);
>  }
>  
> +static int clean_one_remap(struct file_remap *remap, int rmntns_root)
> +{
> +	int ret = 0;
> +	if (rmntns_root == -1)
> +		rmntns_root = mntns_get_root_by_mnt_id(remap->rmnt_id);
> +
> +	if (rmntns_root < 0)
> +		return -1;
> +
> +	pr_info("Unlink remap %s\n", remap->rpath);
> +
> +	ret = unlinkat(rmntns_root, remap->rpath, remap->is_dir ? AT_REMOVEDIR : 0);
> +	if (ret < 0) {
> +		pr_perror("Couldn't unlink remap %s", remap->rpath);
> +		return -1;
> +	}
> +
> +	return 0;
> +}
> +
>  void try_clean_remaps(int ns_fd)
>  {
>  	struct remap_info *ri;
> @@ -647,14 +667,8 @@ static int dump_ghost_file(int _fd, u32 id, const struct stat *st, dev_t phys_de
>  void remap_put(struct file_remap *remap)
>  {
>  	mutex_lock(ghost_file_mutex);
> -	if (--remap->users == 0) {
> -		int mntns_root;
> -
> -		pr_info("Unlink the ghost %s\n", remap->rpath);
> -
> -		mntns_root = mntns_get_root_by_mnt_id(remap->rmnt_id);
> -		unlinkat(mntns_root, remap->rpath, 0);
> -	}
> +	if (--remap->users == 0)
> +		clean_one_remap(remap, -1);
>  	mutex_unlock(ghost_file_mutex);
>  }
>  
> @@ -1514,9 +1528,7 @@ ext:
>  
>  		BUG_ON(!rfi->remap->users);
>  		if (--rfi->remap->users == 0) {
> -			pr_info("Unlink the ghost %s\n", rfi->remap->rpath);
> -			mntns_root = mntns_get_root_by_mnt_id(rfi->remap->rmnt_id);
> -			unlinkat(mntns_root, rfi->remap->rpath, rfi->remap->is_dir ? AT_REMOVEDIR : 0);
> +			clean_one_remap(rfi->remap, mntns_root);

You change the behavior -- originall the mntns_root was re-initialized, but
this patch forces it to get reused. Is that OK?

>  		}
>  
>  		mutex_unlock(ghost_file_mutex);
>