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

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

[Jeff Layton]

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);
 }
 #else
-- 
2.31.1

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

[David Laight]

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)

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

[Jeff Layton]

On Fri, 2021-08-20 at 15:49 +0000, David Laight wrote:
> 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)
> 

ACK. Of course. That really needs to not be inline. I'll fix that up in
my tree.

Thanks!
-- 
Jeff Layton <jlayton@kernel.org>

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

[David Hildenbrand]

On 20.08.21 15:57, Jeff Layton wrote:
> 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");
> +	}

Is there a reason not to use pr_warn_once() ?


-- 
Thanks,

David / dhildenb

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

[Jeff Layton]

On Fri, 2021-08-20 at 17:52 +0200, David Hildenbrand wrote:
> On 20.08.21 15:57, Jeff Layton wrote:
> > 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");
> > +	}
> 
> Is there a reason not to use pr_warn_once() ?
> 
> 

No reason at all. I'll send out a v3 set in a bit with that change.

Thanks!
-- 
Jeff Layton <jlayton@kernel.org>

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

[Steven Rostedt]

On Fri, 20 Aug 2021 17:52:19 +0200
David Hildenbrand <david@redhat.com> wrote:

> > +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");
> > +	}  
> 
> Is there a reason not to use pr_warn_once() ?

You would need a single call though, otherwise each pr_warn_once()
would have its own state that it warned once.

	const char warning[] =
		"======================================================\n"
		"WARNING: the mand mount option is being deprecated and\n"
		"         will be removed in v5.15!\n"
		"======================================================\n";

	pr_warn_once(warning);

-- Steve