mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-18 02:04:05 +08:00
c21dbe20f6
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>
147 lines
4.0 KiB
C
147 lines
4.0 KiB
C
/*
|
|
* Copyright (C) 2008 Red Hat, Inc., Eric Paris <eparis@redhat.com>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2, or (at your option)
|
|
* any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; see the file COPYING. If not, write to
|
|
* the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
|
|
*/
|
|
|
|
#include <linux/list.h>
|
|
#include <linux/mutex.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/srcu.h>
|
|
#include <linux/rculist.h>
|
|
#include <linux/wait.h>
|
|
|
|
#include <linux/fsnotify_backend.h>
|
|
#include "fsnotify.h"
|
|
|
|
#include <linux/atomic.h>
|
|
|
|
/*
|
|
* Final freeing of a group
|
|
*/
|
|
static void fsnotify_final_destroy_group(struct fsnotify_group *group)
|
|
{
|
|
if (group->ops->free_group_priv)
|
|
group->ops->free_group_priv(group);
|
|
|
|
kfree(group);
|
|
}
|
|
|
|
/*
|
|
* Stop queueing new events for this group. Once this function returns
|
|
* fsnotify_add_event() will not add any new events to the group's queue.
|
|
*/
|
|
void fsnotify_group_stop_queueing(struct fsnotify_group *group)
|
|
{
|
|
spin_lock(&group->notification_lock);
|
|
group->shutdown = true;
|
|
spin_unlock(&group->notification_lock);
|
|
}
|
|
|
|
/*
|
|
* Trying to get rid of a group. Remove all marks, flush all events and release
|
|
* the group reference.
|
|
* Note that another thread calling fsnotify_clear_marks_by_group() may still
|
|
* hold a ref to the group.
|
|
*/
|
|
void fsnotify_destroy_group(struct fsnotify_group *group)
|
|
{
|
|
/*
|
|
* Stop queueing new events. The code below is careful enough to not
|
|
* require this but fanotify needs to stop queuing events even before
|
|
* fsnotify_destroy_group() is called and this makes the other callers
|
|
* of fsnotify_destroy_group() to see the same behavior.
|
|
*/
|
|
fsnotify_group_stop_queueing(group);
|
|
|
|
/* clear all inode marks for this group, attach them to destroy_list */
|
|
fsnotify_detach_group_marks(group);
|
|
|
|
/*
|
|
* Wait for fsnotify_mark_srcu period to end and free all marks in
|
|
* destroy_list
|
|
*/
|
|
fsnotify_mark_destroy_list();
|
|
|
|
/*
|
|
* Since we have waited for fsnotify_mark_srcu in
|
|
* fsnotify_mark_destroy_list() there can be no outstanding event
|
|
* notification against this group. So clearing the notification queue
|
|
* of all events is reliable now.
|
|
*/
|
|
fsnotify_flush_notify(group);
|
|
|
|
/*
|
|
* Destroy overflow event (we cannot use fsnotify_destroy_event() as
|
|
* that deliberately ignores overflow events.
|
|
*/
|
|
if (group->overflow_event)
|
|
group->ops->free_event(group->overflow_event);
|
|
|
|
fsnotify_put_group(group);
|
|
}
|
|
|
|
/*
|
|
* Get reference to a group.
|
|
*/
|
|
void fsnotify_get_group(struct fsnotify_group *group)
|
|
{
|
|
atomic_inc(&group->refcnt);
|
|
}
|
|
|
|
/*
|
|
* Drop a reference to a group. Free it if it's through.
|
|
*/
|
|
void fsnotify_put_group(struct fsnotify_group *group)
|
|
{
|
|
if (atomic_dec_and_test(&group->refcnt))
|
|
fsnotify_final_destroy_group(group);
|
|
}
|
|
|
|
/*
|
|
* Create a new fsnotify_group and hold a reference for the group returned.
|
|
*/
|
|
struct fsnotify_group *fsnotify_alloc_group(const struct fsnotify_ops *ops)
|
|
{
|
|
struct fsnotify_group *group;
|
|
|
|
group = kzalloc(sizeof(struct fsnotify_group), GFP_KERNEL);
|
|
if (!group)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
/* set to 0 when there a no external references to this group */
|
|
atomic_set(&group->refcnt, 1);
|
|
atomic_set(&group->num_marks, 0);
|
|
|
|
spin_lock_init(&group->notification_lock);
|
|
INIT_LIST_HEAD(&group->notification_list);
|
|
init_waitqueue_head(&group->notification_waitq);
|
|
group->max_events = UINT_MAX;
|
|
|
|
mutex_init(&group->mark_mutex);
|
|
INIT_LIST_HEAD(&group->marks_list);
|
|
|
|
group->ops = ops;
|
|
|
|
return group;
|
|
}
|
|
|
|
int fsnotify_fasync(int fd, struct file *file, int on)
|
|
{
|
|
struct fsnotify_group *group = file->private_data;
|
|
|
|
return fasync_helper(fd, file, on, &group->fsn_fa) >= 0 ? 0 : -EIO;
|
|
}
|