1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* NFS FS-Cache index structure definition
3 *
4 * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
6 */
7
8 #include <linux/init.h>
9 #include <linux/kernel.h>
10 #include <linux/sched.h>
11 #include <linux/mm.h>
12 #include <linux/nfs_fs.h>
13 #include <linux/nfs_fs_sb.h>
14 #include <linux/in6.h>
15 #include <linux/iversion.h>
16
17 #include "internal.h"
18 #include "fscache.h"
19
20 #define NFSDBG_FACILITY NFSDBG_FSCACHE
21
22 /*
23 * Define the NFS filesystem for FS-Cache. Upon registration FS-Cache sticks
24 * the cookie for the top-level index object for NFS into here. The top-level
25 * index can than have other cache objects inserted into it.
26 */
27 struct fscache_netfs nfs_fscache_netfs = {
28 .name = "nfs",
29 .version = 0,
30 };
31
32 /*
33 * Register NFS for caching
34 */
35 int nfs_fscache_register(void)
36 {
37 return fscache_register_netfs(&nfs_fscache_netfs);
38 }
39
40 /*
41 * Unregister NFS for caching
42 */
43 void nfs_fscache_unregister(void)
44 {
45 fscache_unregister_netfs(&nfs_fscache_netfs);
46 }
47
48 /*
49 * Define the server object for FS-Cache. This is used to describe a server
50 * object to fscache_acquire_cookie(). It is keyed by the NFS protocol and
51 * server address parameters.
52 */
53 const struct fscache_cookie_def nfs_fscache_server_index_def = {
54 .name = "NFS.server",
55 .type = FSCACHE_COOKIE_TYPE_INDEX,
56 };
57
58 /*
59 * Define the superblock object for FS-Cache. This is used to describe a
60 * superblock object to fscache_acquire_cookie(). It is keyed by all the NFS
61 * parameters that might cause a separate superblock.
62 */
63 const struct fscache_cookie_def nfs_fscache_super_index_def = {
64 .name = "NFS.super",
65 .type = FSCACHE_COOKIE_TYPE_INDEX,
66 };
67
68 /*
69 * Consult the netfs about the state of an object
70 * - This function can be absent if the index carries no state data
71 * - The netfs data from the cookie being used as the target is
72 * presented, as is the auxiliary data
73 */
74 static
75 enum fscache_checkaux nfs_fscache_inode_check_aux(void *cookie_netfs_data,
76 const void *data,
77 uint16_t datalen,
78 loff_t object_size)
79 {
80 struct nfs_fscache_inode_auxdata auxdata;
81 struct nfs_inode *nfsi = cookie_netfs_data;
82
83 if (datalen != sizeof(auxdata))
84 return FSCACHE_CHECKAUX_OBSOLETE;
85
86 memset(&auxdata, 0, sizeof(auxdata));
87 auxdata.mtime_sec = nfsi->vfs_inode.i_mtime.tv_sec;
88 auxdata.mtime_nsec = nfsi->vfs_inode.i_mtime.tv_nsec;
89 auxdata.ctime_sec = nfsi->vfs_inode.i_ctime.tv_sec;
90 auxdata.ctime_nsec = nfsi->vfs_inode.i_ctime.tv_nsec;
91
92 if (NFS_SERVER(&nfsi->vfs_inode)->nfs_client->rpc_ops->version == 4)
93 auxdata.change_attr = inode_peek_iversion_raw(&nfsi->vfs_inode);
94
95 if (memcmp(data, &auxdata, datalen) != 0)
96 return FSCACHE_CHECKAUX_OBSOLETE;
97
98 return FSCACHE_CHECKAUX_OKAY;
99 }
100
101 /*
102 * Get an extra reference on a read context.
103 * - This function can be absent if the completion function doesn't require a
104 * context.
105 * - The read context is passed back to NFS in the event that a data read on the
106 * cache fails with EIO - in which case the server must be contacted to
107 * retrieve the data, which requires the read context for security.
108 */
109 static void nfs_fh_get_context(void *cookie_netfs_data, void *context)
110 {
111 get_nfs_open_context(context);
112 }
113
114 /*
115 * Release an extra reference on a read context.
116 * - This function can be absent if the completion function doesn't require a
117 * context.
118 */
119 static void nfs_fh_put_context(void *cookie_netfs_data, void *context)
120 {
121 if (context)
122 put_nfs_open_context(context);
123 }
124
125 /*
126 * Define the inode object for FS-Cache. This is used to describe an inode
127 * object to fscache_acquire_cookie(). It is keyed by the NFS file handle for
128 * an inode.
129 *
130 * Coherency is managed by comparing the copies of i_size, i_mtime and i_ctime
131 * held in the cache auxiliary data for the data storage object with those in
132 * the inode struct in memory.
133 */
134 const struct fscache_cookie_def nfs_fscache_inode_object_def = {
135 .name = "NFS.fh",
136 .type = FSCACHE_COOKIE_TYPE_DATAFILE,
137 .check_aux = nfs_fscache_inode_check_aux,
138 .get_context = nfs_fh_get_context,
139 .put_context = nfs_fh_put_context,
140 };