1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* FS-Cache netfs (client) registration
3 *
4 * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
6 */
7
8 #define FSCACHE_DEBUG_LEVEL COOKIE
9 #include <linux/module.h>
10 #include <linux/slab.h>
11 #include "internal.h"
12
13 /*
14 * register a network filesystem for caching
15 */
__fscache_register_netfs(struct fscache_netfs * netfs)16 int __fscache_register_netfs(struct fscache_netfs *netfs)
17 {
18 struct fscache_cookie *candidate, *cookie;
19
20 _enter("{%s}", netfs->name);
21
22 /* allocate a cookie for the primary index */
23 candidate = fscache_alloc_cookie(&fscache_fsdef_index,
24 &fscache_fsdef_netfs_def,
25 netfs->name, strlen(netfs->name),
26 &netfs->version, sizeof(netfs->version),
27 netfs, 0);
28 if (!candidate) {
29 _leave(" = -ENOMEM");
30 return -ENOMEM;
31 }
32
33 candidate->flags = 1 << FSCACHE_COOKIE_ENABLED;
34
35 /* check the netfs type is not already present */
36 cookie = fscache_hash_cookie(candidate);
37 if (!cookie)
38 goto already_registered;
39 if (cookie != candidate) {
40 trace_fscache_cookie(candidate->debug_id, 1, fscache_cookie_discard);
41 fscache_free_cookie(candidate);
42 }
43
44 fscache_cookie_get(cookie->parent, fscache_cookie_get_register_netfs);
45 atomic_inc(&cookie->parent->n_children);
46
47 netfs->primary_index = cookie;
48
49 pr_notice("Netfs '%s' registered for caching\n", netfs->name);
50 trace_fscache_netfs(netfs);
51 _leave(" = 0");
52 return 0;
53
54 already_registered:
55 fscache_cookie_put(candidate, fscache_cookie_put_dup_netfs);
56 _leave(" = -EEXIST");
57 return -EEXIST;
58 }
59 EXPORT_SYMBOL(__fscache_register_netfs);
60
61 /*
62 * unregister a network filesystem from the cache
63 * - all cookies must have been released first
64 */
__fscache_unregister_netfs(struct fscache_netfs * netfs)65 void __fscache_unregister_netfs(struct fscache_netfs *netfs)
66 {
67 _enter("{%s.%u}", netfs->name, netfs->version);
68
69 fscache_relinquish_cookie(netfs->primary_index, NULL, false);
70 pr_notice("Netfs '%s' unregistered from caching\n", netfs->name);
71
72 _leave("");
73 }
74 EXPORT_SYMBOL(__fscache_unregister_netfs);
75