summaryrefslogtreecommitdiff
path: root/fs/nfs/fscache-index.c
blob: a824050be80792bc687bd04744ad8a42f05c5e78 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
/* NFS FS-Cache index structure definition
 *
 * 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.
 */

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_fs_sb.h>
#include <linux/in6.h>

#include "internal.h"
#include "fscache.h"

#define NFSDBG_FACILITY		NFSDBG_FSCACHE

/*
 * Define the NFS filesystem for FS-Cache.  Upon registration FS-Cache sticks
 * the cookie for the top-level index object for NFS into here.  The top-level
 * index can than have other cache objects inserted into it.
 */
struct fscache_netfs nfs_fscache_netfs = {
	.name		= "nfs",
	.version	= 0,
};

/*
 * Register NFS for caching
 */
int nfs_fscache_register(void)
{
	return fscache_register_netfs(&nfs_fscache_netfs);
}

/*
 * Unregister NFS for caching
 */
void nfs_fscache_unregister(void)
{
	fscache_unregister_netfs(&nfs_fscache_netfs);
}

/*
 * Layout of the key for an NFS server cache object.
 */
struct nfs_server_key {
	uint16_t	nfsversion;		/* NFS protocol version */
	uint16_t	family;			/* address family */
	uint16_t	port;			/* IP port */
	union {
		struct in_addr	ipv4_addr;	/* IPv4 address */
		struct in6_addr ipv6_addr;	/* IPv6 address */
	} addr[0];
};

/*
 * Generate a key to describe a server in the main NFS index
 * - We return the length of the key, or 0 if we can't generate one
 */
static uint16_t nfs_server_get_key(const void *cookie_netfs_data,
				   void *buffer, uint16_t bufmax)
{
	const struct nfs_client *clp = cookie_netfs_data;
	const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) &clp->cl_addr;
	const struct sockaddr_in *sin = (struct sockaddr_in *) &clp->cl_addr;
	struct nfs_server_key *key = buffer;
	uint16_t len = sizeof(struct nfs_server_key);

	key->nfsversion = clp->rpc_ops->version;
	key->family = clp->cl_addr.ss_family;

	memset(key, 0, len);

	switch (clp->cl_addr.ss_family) {
	case AF_INET:
		key->port = sin->sin_port;
		key->addr[0].ipv4_addr = sin->sin_addr;
		len += sizeof(key->addr[0].ipv4_addr);
		break;

	case AF_INET6:
		key->port = sin6->sin6_port;
		key->addr[0].ipv6_addr = sin6->sin6_addr;
		len += sizeof(key->addr[0].ipv6_addr);
		break;

	default:
		printk(KERN_WARNING "NFS: Unknown network family '%d'\n",
		       clp->cl_addr.ss_family);
		len = 0;
		break;
	}

	return len;
}

/*
 * Define the server object for FS-Cache.  This is used to describe a server
 * object to fscache_acquire_cookie().  It is keyed by the NFS protocol and
 * server address parameters.
 */
const struct fscache_cookie_def nfs_fscache_server_index_def = {
	.name		= "NFS.server",
	.type 		= FSCACHE_COOKIE_TYPE_INDEX,
	.get_key	= nfs_server_get_key,
};

/*
 * Generate a key to describe a superblock key in the main NFS index
 */
static uint16_t nfs_super_get_key(const void *cookie_netfs_data,
				  void *buffer, uint16_t bufmax)
{
	const struct nfs_fscache_key *key;
	const struct nfs_server *nfss = cookie_netfs_data;
	uint16_t len;

	key = nfss->fscache_key;
	len = sizeof(key->key) + key->key.uniq_len;
	if (len > bufmax) {
		len = 0;
	} else {
		memcpy(buffer, &key->key, sizeof(key->key));
		memcpy(buffer + sizeof(key->key),
		       key->key.uniquifier, key->key.uniq_len);
	}

	return len;
}

/*
 * Define the superblock object for FS-Cache.  This is used to describe a
 * superblock object to fscache_acquire_cookie().  It is keyed by all the NFS
 * parameters that might cause a separate superblock.
 */
const struct fscache_cookie_def nfs_fscache_super_index_def = {
	.name		= "NFS.super",
	.type 		= FSCACHE_COOKIE_TYPE_INDEX,
	.get_key	= nfs_super_get_key,
};