Re: [PATCH v2 4/7] btrfs: handle error return of close_fs_devices()

[David Sterba <dsterba@suse.cz>]

On Wed, Nov 13, 2019 at 11:27:25AM +0100, Johannes Thumshirn wrote:
> close_fs_devices() will be able to return an error instead of crashing
> after the following patch.
> 
> Prepare btrfs_close_devices() for this.
> 
> Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
> ---
>  fs/btrfs/volumes.c | 11 +++++++----
>  1 file changed, 7 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
> index e5864ca3bb3b..be1fd935edf7 100644
> --- a/fs/btrfs/volumes.c
> +++ b/fs/btrfs/volumes.c
> @@ -1143,10 +1143,10 @@ static int close_fs_devices(struct btrfs_fs_devices *fs_devices)
>  int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
>  {
>  	struct btrfs_fs_devices *seed_devices = NULL;
> -	int ret;
> +	int err, err2 = 0;

Please use ret and ret2.

>  	mutex_lock(&uuid_mutex);
> -	ret = close_fs_devices(fs_devices);
> +	err = close_fs_devices(fs_devices);
>  	if (!fs_devices->opened) {
>  		seed_devices = fs_devices->seed;
>  		fs_devices->seed = NULL;
> @@ -1156,10 +1156,13 @@ int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
>  	while (seed_devices) {
>  		fs_devices = seed_devices;
>  		seed_devices = fs_devices->seed;
> -		close_fs_devices(fs_devices);
> +		err2 = close_fs_devices(fs_devices);

So only the last error value gets propagated to the return statements.
Is that intentional?

>  		free_fs_devices(fs_devices);
>  	}
> -	return ret;
> +
> +	if (err2)
> +		return err2;
> +	return err;