On Mon, 16 Dec 2019 07:43:30 +0000 "Ardelean, Alexandru" <alexandru.Ardelean@xxxxxxxxxx> wrote: > On Sun, 2019-12-15 at 16:25 +0000, Jonathan Cameron wrote: > > [External] > > > > On Wed, 11 Dec 2019 16:59:03 +0200 > > Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx> wrote: > > > > > From: Lars-Peter Clausen <lars@xxxxxxxxxx> > > > > > > The debugfs dir may have multiple files/dirs attached to it. Use > > > debugfs_remove_recursive() to clean it up when the IIO module unloads. > > > > > > Signed-off-by: Lars-Peter Clausen <lars@xxxxxxxxxx> > > > Signed-off-by: Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx> > > > --- > > > > > > Note: note sure if this needs a Fixes tag. It's been in here for ages > > > now, > > > so it may not be a big issue. > > > > There is some argument in favour of doing this as a defensive measure, > > but > > in current IIO debugfs directories are only created by drivers that call > > (indirectly) iio_device_register_debugfs and those must call > > (again indirectly) iio_device_unregister_debugfs which has called > > the recursive free on everything in their directories. So unless > > something > > very odd is going on this isn't a bug. > > > > Am I missing something? > > So, I admit my note is open for interpretation. > [ Rergarding the "Fixes" tag, I'm still not super-clear on when/why/how > it's needed. I'll get there soon though. ] > > This patch has been in our tree since 2012, and I'm not sure why it's using > debugfs_remove_recursive() vs plain debugfs_remove(). > > I sometimes take a look at these old patches, try to make some sense of > them and upstream them, or override them with the version of upstream code. > My intent is to sync ADI code [for IIO] closer to upstream. Which would > make it easier to track any divergence. > > We're not seeing any bug with/without this. > I guess my note about the "Fixes" tag may be a bit clumsy. > > From my side, both debugfs_remove_recursive() & plain debugfs_remove() are > fine. I'd rather leave it be as it kind of avoids people thinking they can get away without cleaning up properly at the higher levels. Thanks, Jonathan > > Thanks > Alex > > > > > > > > drivers/iio/industrialio-core.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/drivers/iio/industrialio-core.c > > > b/drivers/iio/industrialio-core.c > > > index 9a3579943574..dab67cb69fe6 100644 > > > --- a/drivers/iio/industrialio-core.c > > > +++ b/drivers/iio/industrialio-core.c > > > @@ -292,7 +292,7 @@ static void __exit iio_exit(void) > > > if (iio_devt) > > > unregister_chrdev_region(iio_devt, IIO_DEV_MAX); > > > bus_unregister(&iio_bus_type); > > > - debugfs_remove(iio_debugfs_dentry); > > > + debugfs_remove_recursive(iio_debugfs_dentry); > > > } > > > > > > #if defined(CONFIG_DEBUG_FS)
