RE: [PATCH v2 1/2] fs: warn about impending deprecation of mandatory locks

[David Laight <David.Laight@ACULAB.COM>]

From: Jeff Layton
> Sent: 20 August 2021 14:57
> 
> We've had CONFIG_MANDATORY_FILE_LOCKING since 2015 and a lot of distros
> have disabled it. Warn the stragglers that still use "-o mand" that
> we'll be dropping support for that mount option.
> 
> Cc: stable@vger.kernel.org
> Signed-off-by: Jeff Layton <jlayton@kernel.org>
> ---
>  fs/namespace.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/fs/namespace.c b/fs/namespace.c
> index ab4174a3c802..ffab0bb1e649 100644
> --- a/fs/namespace.c
> +++ b/fs/namespace.c
> @@ -1716,8 +1716,16 @@ static inline bool may_mount(void)
>  }
> 
>  #ifdef	CONFIG_MANDATORY_FILE_LOCKING
> +static bool warned_mand;
>  static inline bool may_mandlock(void)
>  {
> +	if (!warned_mand) {
> +		warned_mand = true;
> +		pr_warn("======================================================\n");
> +		pr_warn("WARNING: the mand mount option is being deprecated and\n");
> +		pr_warn("         will be removed in v5.15!\n");
> +		pr_warn("======================================================\n");
> +	}
>  	return capable(CAP_SYS_ADMIN);
>  }

If that is called more than once you don't want the 'inline'.
I doubt it matters is not inlined - hardly a hot path.

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)