From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754648AbaCCLNs (ORCPT ); Mon, 3 Mar 2014 06:13:48 -0500 Received: from cantor2.suse.de ([195.135.220.15]:43680 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754342AbaCCLMf (ORCPT ); Mon, 3 Mar 2014 06:12:35 -0500 From: Jan Kara To: Andrew Morton Cc: LKML , linux-fsdevel@vger.kernel.org, Eric Paris , Jan Kara Subject: [PATCH 3/5] fanotify: Convert access_mutex to spinlock Date: Mon, 3 Mar 2014 12:12:21 +0100 Message-Id: <1393845143-28007-4-git-send-email-jack@suse.cz> X-Mailer: git-send-email 1.8.1.4 In-Reply-To: <1393845143-28007-1-git-send-email-jack@suse.cz> References: <1393845143-28007-1-git-send-email-jack@suse.cz> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org access_mutex is used only to guard operations on access_list. There's no need for sleeping within this lock so just make a spinlock out of it. Signed-off-by: Jan Kara --- fs/notify/fanotify/fanotify_user.c | 14 +++++++------- include/linux/fsnotify_backend.h | 2 +- 2 files changed, 8 insertions(+), 8 deletions(-) diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index 517732dedee2..e0379d725cd9 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -134,7 +134,7 @@ static struct fanotify_perm_event_info *dequeue_event( { struct fanotify_perm_event_info *event, *return_e = NULL; - mutex_lock(&group->fanotify_data.access_mutex); + spin_lock(&group->fanotify_data.access_lock); list_for_each_entry(event, &group->fanotify_data.access_list, fae.fse.list) { if (event->fd != fd) @@ -144,7 +144,7 @@ static struct fanotify_perm_event_info *dequeue_event( return_e = event; break; } - mutex_unlock(&group->fanotify_data.access_mutex); + spin_unlock(&group->fanotify_data.access_lock); pr_debug("%s: found return_re=%p\n", __func__, return_e); @@ -210,10 +210,10 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group, #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS if (event->mask & FAN_ALL_PERM_EVENTS) { FANOTIFY_PE(event)->fd = fd; - mutex_lock(&group->fanotify_data.access_mutex); + spin_lock(&group->fanotify_data.access_lock); list_add_tail(&event->fae.fse.list, &group->fanotify_data.access_list); - mutex_unlock(&group->fanotify_data.access_mutex); + spin_unlock(&group->fanotify_data.access_lock); } #endif @@ -343,7 +343,7 @@ static int fanotify_release(struct inode *ignored, struct file *file) #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS struct fanotify_perm_event_info *event, *next; - mutex_lock(&group->fanotify_data.access_mutex); + spin_lock(&group->fanotify_data.access_lock); atomic_inc(&group->fanotify_data.bypass_perm); @@ -355,7 +355,7 @@ static int fanotify_release(struct inode *ignored, struct file *file) list_del_init(&event->fae.fse.list); event->response = FAN_ALLOW; } - mutex_unlock(&group->fanotify_data.access_mutex); + spin_unlock(&group->fanotify_data.access_lock); wake_up(&group->fanotify_data.access_waitq); #endif @@ -697,7 +697,7 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags) group->fanotify_data.f_flags = event_f_flags; #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS - mutex_init(&group->fanotify_data.access_mutex); + spin_lock_init(&group->fanotify_data.access_lock); init_waitqueue_head(&group->fanotify_data.access_waitq); INIT_LIST_HEAD(&group->fanotify_data.access_list); atomic_set(&group->fanotify_data.bypass_perm, 0); diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index 64cf3ef50696..fc7718c6bd3e 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -178,7 +178,7 @@ struct fsnotify_group { struct fanotify_group_private_data { #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS /* allows a group to block waiting for a userspace response */ - struct mutex access_mutex; + spinlock_t access_lock; struct list_head access_list; wait_queue_head_t access_waitq; atomic_t bypass_perm; -- 1.8.1.4