From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BA3E3EE57E5 for ; Fri, 8 Sep 2023 08:48:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232097AbjIHIsZ (ORCPT ); Fri, 8 Sep 2023 04:48:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35908 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230413AbjIHIsY (ORCPT ); Fri, 8 Sep 2023 04:48:24 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0966A1BDA; Fri, 8 Sep 2023 01:48:20 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 907CAC433C7; Fri, 8 Sep 2023 08:48:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1694162899; bh=bJ7NhyJD9NHnfvbX3T+2HwcdtRMHnTXPcMy23isQEKs=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=bN+I+59/Sp8q4+wM/cbWgOQIf6I6bmKa4YUUBE3j8jip5uylr3YaGQ1YTGd25XFQ0 kYlcjIsFhgzpGTB6TDqGJpCocQXWYzWypwkyLiiS0TYpfkkCQWnJvVAxcEcDh0W58M B612l/FV4ab4IJmRMSeS+9t5WB9WMPcGJHDUt/CwNcDdbbzui8PxyfBn39Ar69dzbk l5f+PztbXfaFepj2nU0RnPRYOcTEGcW8OsLJC/idInpmOJEjOhP6k+iA266PIYRBDx 356qMvyVlyliW4MNaOB3hnRN6sZ/FK+jRhlmrykl3uKFyQa3NOTJ3c1Ckdoenvqf/Q qMmAh5pJUszoQ== Date: Fri, 8 Sep 2023 17:48:15 +0900 From: Masami Hiramatsu (Google) To: Steven Rostedt Cc: LKML , Linux Trace Kernel , Masami Hiramatsu , Mark Rutland , Ajay Kaher , Zheng Yejian , Naresh Kamboju Subject: Re: [PATCH] tracefs/eventfs: Free top level files on removal Message-Id: <20230908174815.9700f5ad32821579d073c86c@kernel.org> In-Reply-To: <20230907175859.6fedbaa2@gandalf.local.home> References: <20230907175859.6fedbaa2@gandalf.local.home> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-trace-kernel@vger.kernel.org On Thu, 7 Sep 2023 17:58:59 -0400 Steven Rostedt wrote: > From: "Steven Rostedt (Google)" > > When an instance is removed, the top level files of the eventfs directory > are not cleaned up. Call the eventfs_remove() on each of the entries to > free them. > > This was found via kmemleak: > > unreferenced object 0xffff8881047c1280 (size 96): > comm "mkdir", pid 924, jiffies 4294906489 (age 2013.077s) > hex dump (first 32 bytes): > 18 31 ed 03 81 88 ff ff 00 31 09 24 81 88 ff ff .1.......1.$.... > 00 00 00 00 00 00 00 00 98 19 7c 04 81 88 ff ff ..........|..... > backtrace: > [<000000000fa46b4d>] kmalloc_trace+0x2a/0xa0 > [<00000000e729cd0c>] eventfs_prepare_ef.constprop.0+0x3a/0x160 > [<000000009032e6a8>] eventfs_add_events_file+0xa0/0x160 > [<00000000fe968442>] create_event_toplevel_files+0x6f/0x130 > [<00000000e364d173>] event_trace_add_tracer+0x14/0x140 > [<00000000411840fa>] trace_array_create_dir+0x52/0xf0 > [<00000000967804fa>] trace_array_create+0x208/0x370 > [<00000000da505565>] instance_mkdir+0x6b/0xb0 > [<00000000dc1215af>] tracefs_syscall_mkdir+0x5b/0x90 > [<00000000a8aca289>] vfs_mkdir+0x272/0x380 > [<000000007709b242>] do_mkdirat+0xfc/0x1d0 > [<00000000c0b6d219>] __x64_sys_mkdir+0x78/0xa0 > [<0000000097b5dd4b>] do_syscall_64+0x3f/0x90 > [<00000000a3f00cfa>] entry_SYSCALL_64_after_hwframe+0x6e/0xd8 > unreferenced object 0xffff888103ed3118 (size 8): > comm "mkdir", pid 924, jiffies 4294906489 (age 2013.077s) > hex dump (first 8 bytes): > 65 6e 61 62 6c 65 00 00 enable.. > backtrace: > [<0000000010f75127>] __kmalloc_node_track_caller+0x51/0x160 > [<000000004b3eca91>] kstrdup+0x34/0x60 > [<0000000050074d7a>] eventfs_prepare_ef.constprop.0+0x53/0x160 > [<000000009032e6a8>] eventfs_add_events_file+0xa0/0x160 > [<00000000fe968442>] create_event_toplevel_files+0x6f/0x130 > [<00000000e364d173>] event_trace_add_tracer+0x14/0x140 > [<00000000411840fa>] trace_array_create_dir+0x52/0xf0 > [<00000000967804fa>] trace_array_create+0x208/0x370 > [<00000000da505565>] instance_mkdir+0x6b/0xb0 > [<00000000dc1215af>] tracefs_syscall_mkdir+0x5b/0x90 > [<00000000a8aca289>] vfs_mkdir+0x272/0x380 > [<000000007709b242>] do_mkdirat+0xfc/0x1d0 > [<00000000c0b6d219>] __x64_sys_mkdir+0x78/0xa0 > [<0000000097b5dd4b>] do_syscall_64+0x3f/0x90 > [<00000000a3f00cfa>] entry_SYSCALL_64_after_hwframe+0x6e/0xd8 > > Fixes: 5bdcd5f5331a2 eventfs: ("Implement removal of meta data from eventfs") > Signed-off-by: Steven Rostedt (Google) Looks good to me. Reviewed-by: Masami Hiramatsu (Google) Thank you, > --- > > This is on top of: > > https://lore.kernel.org/linux-trace-kernel/20230907024710.866917011@goodmis.org/ > > fs/tracefs/event_inode.c | 30 ++++++++++++++++++++++++++---- > 1 file changed, 26 insertions(+), 4 deletions(-) > > diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c > index 609ccb5b7cfc..f168aca45458 100644 > --- a/fs/tracefs/event_inode.c > +++ b/fs/tracefs/event_inode.c > @@ -195,17 +195,39 @@ void eventfs_set_ef_status_free(struct tracefs_inode *ti, struct dentry *dentry) > { > struct tracefs_inode *ti_parent; > struct eventfs_inode *ei; > - struct eventfs_file *ef; > - > - mutex_lock(&eventfs_mutex); > + struct eventfs_file *ef, *tmp; > > /* The top level events directory may be freed by this */ > if (unlikely(ti->flags & TRACEFS_EVENT_TOP_INODE)) { > + LIST_HEAD(ef_del_list); > + > + mutex_lock(&eventfs_mutex); > + > ei = ti->private; > + > + /* Record all the top level files */ > + list_for_each_entry_srcu(ef, &ei->e_top_files, list, > + lockdep_is_held(&eventfs_mutex)) { > + list_add_tail(&ef->del_list, &ef_del_list); > + } > + > + /* Nothing should access this, but just in case! */ > + ti->private = NULL; > + > + mutex_unlock(&eventfs_mutex); > + > + /* Now safely free the top level files and their children */ > + list_for_each_entry_safe(ef, tmp, &ef_del_list, del_list) { > + list_del(&ef->del_list); > + eventfs_remove(ef); > + } > + > kfree(ei); > - goto out; > + return; > } > > + mutex_lock(&eventfs_mutex); > + > ti_parent = get_tracefs(dentry->d_parent->d_inode); > if (!ti_parent || !(ti_parent->flags & TRACEFS_EVENT_INODE)) > goto out; > -- > 2.40.1 > -- Masami Hiramatsu (Google)