On Tue, 2024-02-27 at 06:29 -0800, Ben Greear wrote:
> > --- a/fs/debugfs/inode.c
> > +++ b/fs/debugfs/inode.c
> > @@ -751,13 +751,19 @@ static void __debugfs_file_removed(struct dentry *dentry)
> > if ((unsigned long)fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT)
> > return;
> >
> > - /* if we hit zero, just wait for all to finish */
> > - if (!refcount_dec_and_test(&fsd->active_users)) {
> > - wait_for_completion(&fsd->active_users_drained);
> > - return;
> > - }
> > + /*
> > + * Now that debugfs_file_get() no longer sees a valid entry,
> > + * decrement the refcount to remove the initial reference.
> > + */
> > + refcount_dec(&fsd->active_users);
>
> [ 94.576688] ------------[ cut here ]------------
> [ 94.576699] refcount_t: decrement hit 0; leaking memory.
>
Ah ... right, refcount_dec() doesn't like to hit 0, it's not meant for
this path.
I guess we can
if (refcount_dec_and_test(...))
return;
while (refcount_read(...)) { ... }
johannes
