From patchwork Wed Jan 31 21:37:00 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Rostedt X-Patchwork-Id: 13539987 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6208A39AD0; Wed, 31 Jan 2024 21:36:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706737007; cv=none; b=V1OTfyDX+E0nCM6SL4eD863zMJYq/JkYu8xv/XZFILXhBTanuo6x9/pQWyjILr7puSG1Mv0d93iPh+sPX9JsfDoimQhCVHhqc6iKHuaPocHLhOA4M8KP/uja4AXcKAcXn4BtX8k33cI5QPRCQIxvwBIu6EkZ6MT0YMXCOz1CKOA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706737007; c=relaxed/simple; bh=/hq3X/Hp2ZFRDTAg8t+kikWWPidIFF7L9VYN7g8mrtE=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type; b=Aclisf6RAZJgIr0f2b8HboE9nJjT5nCO2ud/bfWN1zul2+g9yKP9nR4W8s/yDmjtaiMfI6i9djyZSTtXQKEjetsmf4IkbF9/yPNwqN2r3pnvH1Wx1jh2vcd2i/GGHbEsK35uwFM6UOzV5NdsNyrfSRZ/qDlr7Jz2/9HEaOoKBgc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3B244C433F1; Wed, 31 Jan 2024 21:36:46 +0000 (UTC) Date: Wed, 31 Jan 2024 16:37:00 -0500 From: Steven Rostedt To: LKML , Linux Trace Kernel Cc: Masami Hiramatsu , Mathieu Desnoyers , Linus Torvalds Subject: [PATCH] eventfs: Warn if an eventfs_inode is freed without is_freed being set Message-ID: <20240131163700.2342a110@gandalf.local.home> X-Mailer: Claws Mail 3.19.1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: "Steven Rostedt (Google)" There should never be a case where an evenfs_inode is being freed without is_freed being set. Add a WARN_ON_ONCE() if it ever happens. That would mean there was one too many put_ei()s. As put_ei() is also called on failure cases to free the ei, add a free_ei() helper that sets the is_freed and then calls put_ei(). Signed-off-by: Steven Rostedt (Google) --- fs/tracefs/event_inode.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c index 31cbe38739fa..463920295237 100644 --- a/fs/tracefs/event_inode.c +++ b/fs/tracefs/event_inode.c @@ -73,6 +73,9 @@ enum { static void release_ei(struct kref *ref) { struct eventfs_inode *ei = container_of(ref, struct eventfs_inode, kref); + + WARN_ON_ONCE(!ei->is_freed); + kfree(ei->entry_attrs); kfree_const(ei->name); kfree_rcu(ei, rcu); @@ -84,6 +87,14 @@ static inline void put_ei(struct eventfs_inode *ei) kref_put(&ei->kref, release_ei); } +static inline void free_ei(struct eventfs_inode *ei) +{ + if (ei) { + ei->is_freed = 1; + put_ei(ei); + } +} + static inline struct eventfs_inode *get_ei(struct eventfs_inode *ei) { if (ei) @@ -684,7 +695,7 @@ struct eventfs_inode *eventfs_create_dir(const char *name, struct eventfs_inode /* Was the parent freed? */ if (list_empty(&ei->list)) { - put_ei(ei); + free_ei(ei); ei = NULL; } return ei; @@ -775,7 +786,7 @@ struct eventfs_inode *eventfs_create_events_dir(const char *name, struct dentry return ei; fail: - put_ei(ei); + free_ei(ei); tracefs_failed_creating(dentry); return ERR_PTR(-ENOMEM); } @@ -806,9 +817,8 @@ static void eventfs_remove_rec(struct eventfs_inode *ei, int level) list_for_each_entry(ei_child, &ei->children, list) eventfs_remove_rec(ei_child, level + 1); - ei->is_freed = 1; list_del(&ei->list); - put_ei(ei); + free_ei(ei); } /**