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authorJan Kara <jack@suse.cz>2016-10-08 01:56:52 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2016-10-08 03:46:26 +0200
commitc21dbe20f606219fe54faf555b7bc5565487c58f (patch)
tree91e57fe4aad1f1358f099521b570d9daf7b6a758 /fs/notify/notification.c
parentfsnotify: drop notification_mutex before destroying event (diff)
downloadlinux-c21dbe20f606219fe54faf555b7bc5565487c58f.tar.xz
linux-c21dbe20f606219fe54faf555b7bc5565487c58f.zip
fsnotify: convert notification_mutex to a spinlock
notification_mutex is used to protect the list of pending events. As such there's no reason to use a sleeping lock for it. Convert it to a spinlock. [jack@suse.cz: fixed version] Link: http://lkml.kernel.org/r/1474031567-1831-1-git-send-email-jack@suse.cz Link: http://lkml.kernel.org/r/1473797711-14111-5-git-send-email-jack@suse.cz Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> Tested-by: Guenter Roeck <linux@roeck-us.net> Cc: Miklos Szeredi <mszeredi@redhat.com> Cc: Eric Paris <eparis@redhat.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/notify/notification.c')
-rw-r--r--fs/notify/notification.c27
1 files changed, 15 insertions, 12 deletions
diff --git a/fs/notify/notification.c b/fs/notify/notification.c
index 7d563dea52a4..8a7a8cd041e8 100644
--- a/fs/notify/notification.c
+++ b/fs/notify/notification.c
@@ -63,7 +63,8 @@ EXPORT_SYMBOL_GPL(fsnotify_get_cookie);
/* return true if the notify queue is empty, false otherwise */
bool fsnotify_notify_queue_is_empty(struct fsnotify_group *group)
{
- BUG_ON(!mutex_is_locked(&group->notification_mutex));
+ BUG_ON(IS_ENABLED(CONFIG_SMP) &&
+ !spin_is_locked(&group->notification_lock));
return list_empty(&group->notification_list) ? true : false;
}
@@ -95,10 +96,10 @@ int fsnotify_add_event(struct fsnotify_group *group,
pr_debug("%s: group=%p event=%p\n", __func__, group, event);
- mutex_lock(&group->notification_mutex);
+ spin_lock(&group->notification_lock);
if (group->shutdown) {
- mutex_unlock(&group->notification_mutex);
+ spin_unlock(&group->notification_lock);
return 2;
}
@@ -106,7 +107,7 @@ int fsnotify_add_event(struct fsnotify_group *group,
ret = 2;
/* Queue overflow event only if it isn't already queued */
if (!list_empty(&group->overflow_event->list)) {
- mutex_unlock(&group->notification_mutex);
+ spin_unlock(&group->notification_lock);
return ret;
}
event = group->overflow_event;
@@ -116,7 +117,7 @@ int fsnotify_add_event(struct fsnotify_group *group,
if (!list_empty(list) && merge) {
ret = merge(list, event);
if (ret) {
- mutex_unlock(&group->notification_mutex);
+ spin_unlock(&group->notification_lock);
return ret;
}
}
@@ -124,7 +125,7 @@ int fsnotify_add_event(struct fsnotify_group *group,
queue:
group->q_len++;
list_add_tail(&event->list, list);
- mutex_unlock(&group->notification_mutex);
+ spin_unlock(&group->notification_lock);
wake_up(&group->notification_waitq);
kill_fasync(&group->fsn_fa, SIGIO, POLL_IN);
@@ -139,7 +140,8 @@ struct fsnotify_event *fsnotify_remove_first_event(struct fsnotify_group *group)
{
struct fsnotify_event *event;
- BUG_ON(!mutex_is_locked(&group->notification_mutex));
+ BUG_ON(IS_ENABLED(CONFIG_SMP) &&
+ !spin_is_locked(&group->notification_lock));
pr_debug("%s: group=%p\n", __func__, group);
@@ -161,7 +163,8 @@ struct fsnotify_event *fsnotify_remove_first_event(struct fsnotify_group *group)
*/
struct fsnotify_event *fsnotify_peek_first_event(struct fsnotify_group *group)
{
- BUG_ON(!mutex_is_locked(&group->notification_mutex));
+ BUG_ON(IS_ENABLED(CONFIG_SMP) &&
+ !spin_is_locked(&group->notification_lock));
return list_first_entry(&group->notification_list,
struct fsnotify_event, list);
@@ -175,14 +178,14 @@ void fsnotify_flush_notify(struct fsnotify_group *group)
{
struct fsnotify_event *event;
- mutex_lock(&group->notification_mutex);
+ spin_lock(&group->notification_lock);
while (!fsnotify_notify_queue_is_empty(group)) {
event = fsnotify_remove_first_event(group);
- mutex_unlock(&group->notification_mutex);
+ spin_unlock(&group->notification_lock);
fsnotify_destroy_event(group, event);
- mutex_lock(&group->notification_mutex);
+ spin_lock(&group->notification_lock);
}
- mutex_unlock(&group->notification_mutex);
+ spin_unlock(&group->notification_lock);
}
/*