79 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			79 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* 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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| 
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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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| /*
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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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| 
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| 	_enter("{%s}", netfs->name);
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| 
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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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| 
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| 	candidate->flags = 1 << FSCACHE_COOKIE_ENABLED;
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| 
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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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| 
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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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| 
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| 	netfs->primary_index = cookie;
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| 
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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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| 
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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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| /*
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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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| 
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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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| 
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| 	_leave("");
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| }
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| EXPORT_SYMBOL(__fscache_unregister_netfs);
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