On Thu, Jun 13, 2019 at 10:33:23AM -0400, Jason Baron wrote:
> On 6/12/19 11:35 AM, Greg Kroah-Hartman wrote:
> > When calling debugfs functions, there is no need to ever check the
> > return value. The function can work or not, but the code logic should
> > never do something different based on this.
> >
> > Cc: Jason Baron <jba...@akamai.com>
> > Cc: linux-kernel@vger.kernel.org
> > Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
> > ---
> > lib/dynamic_debug.c | 12 +++---------
> > 1 file changed, 3 insertions(+), 9 deletions(-)
> >
> > diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
> > index 8a16c2d498e9..c60409138e13 100644
> > --- a/lib/dynamic_debug.c
> > +++ b/lib/dynamic_debug.c
> > @@ -993,20 +993,14 @@ static __initdata int ddebug_init_success;
> >
> > static int __init dynamic_debug_init_debugfs(void)
> > {
> > - struct dentry *dir, *file;
> > + struct dentry *dir;
> >
> > if (!ddebug_init_success)
> > return -ENODEV;
> >
> > dir = debugfs_create_dir("dynamic_debug", NULL);
> > - if (!dir)
> > - return -ENOMEM;
> > - file = debugfs_create_file("control", 0644, dir, NULL,
> > - &ddebug_proc_fops);
> > - if (!file) {
> > - debugfs_remove(dir);
> > - return -ENOMEM;
> > - }
> > + debugfs_create_file("control", 0644, dir, NULL, &ddebug_proc_fops);
> > +
> > return 0;
> > }
> >
> >
>
> Looks like debugfs_create_dir() can return NULL,
No it can not.
> and in that case if its passed to debugfs_create_file() then the
> 'control' file ends up in the root of debugfs?
If it could, yes, that is what would happen.
> I think its better to just not create the file then have it in the
> wrong place so maybe the file creation should be guarded by
> if(IS_ERR_OR_NULL(dir)).
As debugfs_create_dir() can not return NULL, you don't have to worry
about this :)
thanks,
greg k-h
