From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Al Viro <viro@zeniv.linux.org.uk>
Cc: Kuyo Chang <kuyo.chang@mediatek.com>,
major.chen@samsung.com, Ingo Molnar <mingo@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Juri Lelli <juri.lelli@redhat.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Steven Rostedt <rostedt@goodmis.org>,
Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>,
Daniel Bristot de Oliveira <bristot@redhat.com>,
Valentin Schneider <vschneid@redhat.com>,
Matthias Brugger <matthias.bgg@gmail.com>,
wsd_upstream@mediatek.com, hongfei.tang@samsung.com,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-mediatek@lists.infradead.org
Subject: Re: [PATCH 1/1] sched/debug: fix dentry leak in update_sched_domain_debugfs
Date: Fri, 2 Sep 2022 16:56:05 +0200 [thread overview]
Message-ID: <YxIZhWB2tCXzlzWj@kroah.com> (raw)
In-Reply-To: <YxIX96nUnwz56fte@ZenIV>
On Fri, Sep 02, 2022 at 03:49:27PM +0100, Al Viro wrote:
> On Fri, Sep 02, 2022 at 11:11:54AM +0200, Greg Kroah-Hartman wrote:
>
> > +/**
> > + * debugfs_lookup_and_remove - lookup a directory or file and recursively remove it
> > + * @name: a pointer to a string containing the name of the item to look up.
> > + * @parent: a pointer to the parent dentry of the item.
> > + *
> > + * This is the equlivant of doing something like
> > + * debugfs_remove(debugfs_lookup(..)) but with the proper reference counting
> > + * handled for the directory being looked up.
> > + */
> > +void debugfs_lookup_and_remove(const char *name, struct dentry *parent)
> > +{
> > + struct dentry *dentry;
> > +
> > + dentry = debugfs_lookup(name, parent);
> > + if (IS_ERR_OR_NULL(dentry))
> > + return;
>
> Could somebody explain how could that return ERR_PTR()?
If debugfs is not enabled then debugfs_lookup() will return an
ERR_PTR(). But, doh, this _IS_ debugfs so you are right, that will
never happen.
> Incidentally, IS_ERR_OR_NULL is almost always a sign of bad interface - or
> that of lazy cargo-culting. Please, don't propagate that garbage... ;-/
Fair enough, I'll fix that up, many thanks for noticing it.
greg k-h
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prev parent reply other threads:[~2022-09-02 14:57 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-02 3:15 [PATCH 1/1] sched/debug: fix dentry leak in update_sched_domain_debugfs Kuyo Chang
2022-09-02 5:26 ` Greg Kroah-Hartman
2022-09-02 6:40 ` Kuyo Chang
2022-09-02 6:58 ` Greg Kroah-Hartman
2022-09-02 7:36 ` Kuyo Chang
2022-09-02 9:11 ` Greg Kroah-Hartman
2022-09-02 10:47 ` Kuyo Chang
2022-09-02 12:47 ` Greg Kroah-Hartman
2022-09-02 14:49 ` Al Viro
2022-09-02 14:56 ` Greg Kroah-Hartman [this message]
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