On Fri, Mar 26, 2021 at 12:18:47PM +0100, Peter Zijlstra wrote:
> On Fri, Mar 26, 2021 at 12:05:07PM +0100, Greg KH wrote:
> > On Fri, Mar 26, 2021 at 11:33:58AM +0100, Peter Zijlstra wrote:
> > >
> > > Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org>
> >
> > No changelog text? :(
>
> Yeah, didn't really know what to say that the Subject didn't already do.
>
> > > +/**
> > > + * debugfs_create_str - create a debugfs file that is used to read and
> > > write a string value
> > > + * @name: a pointer to a string containing the name of the file to
> > > create.
> > > + * @mode: the permission that the file should have
> > > + * @parent: a pointer to the parent dentry for this file. This should
> > > be a
> > > + * directory dentry if set. If this parameter is %NULL, then
> > > the
> > > + * file will be created in the root of the debugfs filesystem.
> > > + * @value: a pointer to the variable that the file should read to and
> > > write
> > > + * from.
> > > + *
> > > + * This function creates a file in debugfs with the given name that
> > > + * contains the value of the variable @value. If the @mode variable is
> > > so
> > > + * set, it can be read from, and written to.
> > > + *
> > > + * This function will return a pointer to a dentry if it succeeds. This
> > > + * pointer must be passed to the debugfs_remove() function when the file
> > > is
> > > + * to be removed (no automatic cleanup happens if your module is
> > > unloaded,
> > > + * you are responsible here.) If an error occurs, ERR_PTR(-ERROR) will
> > > be
> > > + * returned.
> > > + *
> > > + * NOTE: when writing is enabled it will replace the string, string
> > > lifetime is
> > > + * assumed to be RCU managed.
> > > + *
> > > + * If debugfs is not enabled in the kernel, the value ERR_PTR(-ENODEV)
> > > will
> > > + * be returned.
> > > + */
> > > +struct dentry *debugfs_create_str(const char *name, umode_t mode,
> > > + struct dentry *parent, char **value)
> >
> > Please have this return void, no need for me to have to clean up
> > afterward later on :)
>
> That would make it inconsistent with debugfs_create_{bool,blob}() from
> which I copiously 'borrowed'.
As mentioned on IRC, I am trying to get rid of the return value, those
are the only 2 holdouts given their current use in some of the cruftier
areas of the kernel at the moment :(
> Also, the return dentry might be useful with debugfs_create_symlink(),
> but you're right in that most other create_file wrappers return void.
Great, change that and limit the size of the string that can be written
and it looks good to me, thanks for adding this.
greg k-h
