forked from Minki/linux
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>
57 lines
1.3 KiB
C
57 lines
1.3 KiB
C
/* netfs cookie management
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*
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* Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#define FSCACHE_DEBUG_LEVEL COOKIE
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#include <linux/module.h>
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#include <linux/slab.h>
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#include "internal.h"
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struct kmem_cache *fscache_cookie_jar;
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/*
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* initialise an cookie jar slab element prior to any use
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*/
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void fscache_cookie_init_once(void *_cookie)
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{
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struct fscache_cookie *cookie = _cookie;
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memset(cookie, 0, sizeof(*cookie));
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spin_lock_init(&cookie->lock);
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INIT_HLIST_HEAD(&cookie->backing_objects);
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}
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/*
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* destroy a cookie
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*/
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void __fscache_cookie_put(struct fscache_cookie *cookie)
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{
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struct fscache_cookie *parent;
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_enter("%p", cookie);
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for (;;) {
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_debug("FREE COOKIE %p", cookie);
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parent = cookie->parent;
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BUG_ON(!hlist_empty(&cookie->backing_objects));
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kmem_cache_free(fscache_cookie_jar, cookie);
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if (!parent)
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break;
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cookie = parent;
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BUG_ON(atomic_read(&cookie->usage) <= 0);
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if (!atomic_dec_and_test(&cookie->usage))
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break;
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}
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_leave("");
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}
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