mirror of
https://github.com/adulau/aha.git
synced 2024-12-28 11:46:19 +00:00
955d00917f
Provide a slab from which can be allocated the FS-Cache cookies that will be presented to the netfs. Also provide a slab constructor and a function to recursively discard a cookie and its ancestor chain. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Steve Dickson <steved@redhat.com> Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Tested-by: Daire Byrne <Daire.Byrne@framestore.com>
56 lines
1.3 KiB
C
56 lines
1.3 KiB
C
/* netfs cookie management
|
|
*
|
|
* Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved.
|
|
* Written by David Howells (dhowells@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 of the License, or (at your option) any later version.
|
|
*/
|
|
|
|
#define FSCACHE_DEBUG_LEVEL COOKIE
|
|
#include <linux/module.h>
|
|
#include <linux/slab.h>
|
|
#include "internal.h"
|
|
|
|
struct kmem_cache *fscache_cookie_jar;
|
|
|
|
/*
|
|
* initialise an cookie jar slab element prior to any use
|
|
*/
|
|
void fscache_cookie_init_once(void *_cookie)
|
|
{
|
|
struct fscache_cookie *cookie = _cookie;
|
|
|
|
memset(cookie, 0, sizeof(*cookie));
|
|
spin_lock_init(&cookie->lock);
|
|
INIT_HLIST_HEAD(&cookie->backing_objects);
|
|
}
|
|
|
|
/*
|
|
* destroy a cookie
|
|
*/
|
|
void __fscache_cookie_put(struct fscache_cookie *cookie)
|
|
{
|
|
struct fscache_cookie *parent;
|
|
|
|
_enter("%p", cookie);
|
|
|
|
for (;;) {
|
|
_debug("FREE COOKIE %p", cookie);
|
|
parent = cookie->parent;
|
|
BUG_ON(!hlist_empty(&cookie->backing_objects));
|
|
kmem_cache_free(fscache_cookie_jar, cookie);
|
|
|
|
if (!parent)
|
|
break;
|
|
|
|
cookie = parent;
|
|
BUG_ON(atomic_read(&cookie->usage) <= 0);
|
|
if (!atomic_dec_and_test(&cookie->usage))
|
|
break;
|
|
}
|
|
|
|
_leave("");
|
|
}
|