Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759903AbZGIIWa (ORCPT ); Thu, 9 Jul 2009 04:22:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757101AbZGIIWR (ORCPT ); Thu, 9 Jul 2009 04:22:17 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:59156 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1756258AbZGIIWQ (ORCPT ); Thu, 9 Jul 2009 04:22:16 -0400 Message-ID: <4A55A8BE.9010707@cn.fujitsu.com> Date: Thu, 09 Jul 2009 16:22:22 +0800 From: Xiao Guangrong User-Agent: Thunderbird 2.0.0.6 (Windows/20070728) MIME-Version: 1.0 To: Ingo Molnar CC: Frederic Weisbecker , Steven Rostedt , Tom Zanussi , LKML Subject: [PATCH 2/2] tracing/filter: remove empty subsystem and it's directory References: <4A55A83C.1030005@cn.fujitsu.com> In-Reply-To: <4A55A83C.1030005@cn.fujitsu.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2827 Lines: 104 Remove empty subsystem and it's directory when module unload. Before patch: # rmmod trace-events-sample.ko # ls sample enable filter After patch: # rmmod trace-events-sample.ko # ls sample ls: cannot access sample: No such file or directory Signed-off-by: Xiao Guangrong --- kernel/trace/trace.h | 1 + kernel/trace/trace_events.c | 32 +++++++++++++++++++++++++++++++- 2 files changed, 32 insertions(+), 1 deletions(-) diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 61b4e94..0e7de4b 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -780,6 +780,7 @@ struct event_subsystem { const char *name; struct dentry *entry; void *filter; + int nr_events; }; struct filter_pred; diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index fecac13..90cf936 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -851,8 +851,10 @@ event_subsystem_dir(const char *name, struct dentry *d_events) /* First see if we did not already create this dir */ list_for_each_entry(system, &event_subsystems, list) { - if (strcmp(system->name, name) == 0) + if (strcmp(system->name, name) == 0) { + system->nr_events++; return system->entry; + } } /* need to create new entry */ @@ -871,6 +873,7 @@ event_subsystem_dir(const char *name, struct dentry *d_events) return d_events; } + system->nr_events = 1; system->name = kstrdup(name, GFP_KERNEL); if (!system->name) { debugfs_remove(system->entry); @@ -905,6 +908,32 @@ event_subsystem_dir(const char *name, struct dentry *d_events) return system->entry; } +static void remove_subsystem_dir(const char *name) +{ + struct event_subsystem *system; + + if (strcmp(name, TRACE_SYSTEM) == 0) + return; + + list_for_each_entry(system, &event_subsystems, list) { + if (strcmp(system->name, name) == 0) { + if (!--system->nr_events) { + struct event_filter *filter = system->filter; + + debugfs_remove_recursive(system->entry); + list_del(&system->list); + if (filter) { + kfree(filter->filter_string); + kfree(filter); + } + kfree(system->name); + kfree(system); + } + break; + } + } +} + static int event_create_dir(struct ftrace_event_call *call, struct dentry *d_events, const struct file_operations *id, @@ -1079,6 +1108,7 @@ static void trace_module_remove_events(struct module *mod) list_del(&call->list); trace_destroy_fields(call); destroy_preds(call); + remove_subsystem_dir(call->system); } } -- 1.6.1.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/