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