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/* FS-Cache netfs (client) registration
*
* Copyright (C) 2008 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 Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/
#define FSCACHE_DEBUG_LEVEL COOKIE
#include <linux/module.h>
#include <linux/slab.h>
#include "internal.h"
/*
* register a network filesystem for caching
*/
int __fscache_register_netfs(struct fscache_netfs *netfs)
{
struct fscache_cookie *candidate, *cookie;
_enter("{%s}", netfs->name);
/* allocate a cookie for the primary index */
candidate = fscache_alloc_cookie(&fscache_fsdef_index,
&fscache_fsdef_netfs_def,
netfs->name, strlen(netfs->name),
&netfs->version, sizeof(netfs->version),
netfs, 0);
if (!candidate) {
_leave(" = -ENOMEM");
return -ENOMEM;
}
candidate->flags = 1 << FSCACHE_COOKIE_ENABLED;
/* check the netfs type is not already present */
cookie = fscache_hash_cookie(candidate);
if (!cookie)
goto already_registered;
if (cookie != candidate) {
trace_fscache_cookie(candidate, fscache_cookie_discard, 1);
fscache_free_cookie(candidate);
}
fscache_cookie_get(cookie->parent, fscache_cookie_get_register_netfs);
atomic_inc(&cookie->parent->n_children);
netfs->primary_index = cookie;
pr_notice("Netfs '%s' registered for caching\n", netfs->name);
trace_fscache_netfs(netfs);
_leave(" = 0");
return 0;
already_registered:
fscache_cookie_put(candidate, fscache_cookie_put_dup_netfs);
_leave(" = -EEXIST");
return -EEXIST;
}
EXPORT_SYMBOL(__fscache_register_netfs);
/*
* unregister a network filesystem from the cache
* - all cookies must have been released first
*/
void __fscache_unregister_netfs(struct fscache_netfs *netfs)
{
_enter("{%s.%u}", netfs->name, netfs->version);
fscache_relinquish_cookie(netfs->primary_index, NULL, false);
pr_notice("Netfs '%s' unregistered from caching\n", netfs->name);
_leave("");
}
EXPORT_SYMBOL(__fscache_unregister_netfs);
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