Re: [PATCH] zonefs: convert zonefs to use the new mount api

[Damien Le Moal <dlemoal@kernel.org>]

On 2/11/24 12:36, Ian Kent wrote:
>>> +static void zonefs_free_fc(struct fs_context *fc)
>>> +{
>>> +	struct zonefs_context *ctx = fc->fs_private;
>> I do not think you need this variable.
> 
> That's a fair comment but it says fs_private contains the fs context
> 
> for the casual reader.
> 
>>
>>> +
>>> +	kfree(ctx);
>> Is it safe to not set fc->fs_private to NULL ?
> 
> I think it's been safe to call kfree() with a NULL argument for ages.

That I know, which is why I asked if *not* setting fc->fs_private to NULL after
the kfree is safe. Because if another call to kfree for that pointer is done, we
will endup with a double free oops. But as long as the mount API guarantees that
it will not happen, then OK.

> 
> 
> This could be done but so far the convention with mount api code
> 
> appears to have been to add the local variable which I thought was for
> descriptive purposes but it could just be the result of cut and pastes.

Keeping the variable is fine. After all, that is not the fast path :)


-- 
Damien Le Moal
Western Digital Research