Re: [PATCH v3 2/3] rust: miscdevice: access the `struct miscdevice` from fops->open()

[Lee Jones <lee@kernel.org>]

On Wed, 11 Dec 2024, Lee Jones wrote:

> On Tue, 10 Dec 2024, Alice Ryhl wrote:
> 
> > Providing access to the underlying `struct miscdevice` is useful for
> > various reasons. For example, this allows you access the miscdevice's
> > internal `struct device` for use with the `dev_*` printing macros.
> > 
> > Note that since the underlying `struct miscdevice` could get freed at
> > any point after the fops->open() call (if misc_deregister is called),
> > only the open call is given access to it. To use `dev_*` printing macros
> > from other fops hooks, take a refcount on `miscdevice->this_device` to
> > keep it alive. See the linked thread for further discussion on the
> > lifetime of `struct miscdevice`.
> > 
> > Link: https://lore.kernel.org/r/2024120951-botanist-exhale-4845@gregkh
> > Signed-off-by: Alice Ryhl <aliceryhl@google.com>
> > ---
> >  rust/kernel/miscdevice.rs | 30 ++++++++++++++++++++++--------
> >  1 file changed, 22 insertions(+), 8 deletions(-)
> 
> Reviewed-by: Lee Jones <lee@kernel.org>

Tested-by: Lee Jones <lee@kernel.org>

-- 
Lee Jones [李琼斯]