projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 726dd7ff DH |
1 | /* FS-Cache netfs (client) registration |
| 2 | * | |
| 3 | * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved. | |
| 4 | * Written by David Howells (dhowells@redhat.com) | |
| 5 | * | |
| 6 | * This program is free software; you can redistribute it and/or | |
| 7 | * modify it under the terms of the GNU General Public Licence | |
| 8 | * as published by the Free Software Foundation; either version | |
| 9 | * 2 of the Licence, or (at your option) any later version. | |
| 10 | */ | |
| 11 | ||
| 12 | #define FSCACHE_DEBUG_LEVEL COOKIE | |
| 13 | #include <linux/module.h> | |
| 14 | #include <linux/slab.h> | |
| 15 | #include "internal.h" | |
| 16 | ||
| 726dd7ff DH |
17 | /* |
| 18 | * register a network filesystem for caching | |
| 19 | */ | |
| 20 | int __fscache_register_netfs(struct fscache_netfs *netfs) | |
| 21 | { | |
| ec0328e4 | 22 | struct fscache_cookie *candidate, *cookie; |
| 726dd7ff DH |
23 | |
| 24 | _enter("{%s}", netfs->name); | |
| 25 | ||
| 726dd7ff | 26 | /* allocate a cookie for the primary index */ |
| ec0328e4 DH |
27 | candidate = fscache_alloc_cookie(&fscache_fsdef_index, |
| 28 | &fscache_fsdef_netfs_def, | |
| 29 | netfs->name, strlen(netfs->name), | |
| 30 | &netfs->version, sizeof(netfs->version), | |
| 31 | netfs, 0); | |
| 32 | if (!candidate) { | |
| 726dd7ff DH |
33 | _leave(" = -ENOMEM"); |
| 34 | return -ENOMEM; | |
| 35 | } | |
| 36 | ||
| ec0328e4 | 37 | candidate->flags = 1 << FSCACHE_COOKIE_ENABLED; |
| 726dd7ff DH |
38 | |
| 39 | /* check the netfs type is not already present */ | |
| ec0328e4 DH |
40 | cookie = fscache_hash_cookie(candidate); |
| 41 | if (!cookie) | |
| 42 | goto already_registered; | |
| 43 | if (cookie != candidate) { | |
| 44 | trace_fscache_cookie(candidate, fscache_cookie_discard, 1); | |
| 45 | fscache_free_cookie(candidate); | |
| 726dd7ff DH |
46 | } |
| 47 | ||
| a18feb55 | 48 | fscache_cookie_get(cookie->parent, fscache_cookie_get_register_netfs); |
| b130ed59 | 49 | atomic_inc(&cookie->parent->n_children); |
| 86108c2e | 50 | |
| b130ed59 | 51 | netfs->primary_index = cookie; |
| 726dd7ff | 52 | |
| 36dfd116 | 53 | pr_notice("Netfs '%s' registered for caching\n", netfs->name); |
| a18feb55 | 54 | trace_fscache_netfs(netfs); |
| ec0328e4 DH |
55 | _leave(" = 0"); |
| 56 | return 0; | |
| 726dd7ff DH |
57 | |
| 58 | already_registered: | |
| ec0328e4 DH |
59 | fscache_cookie_put(candidate, fscache_cookie_put_dup_netfs); |
| 60 | _leave(" = -EEXIST"); | |
| 61 | return -EEXIST; | |
| 726dd7ff DH |
62 | } |
| 63 | EXPORT_SYMBOL(__fscache_register_netfs); | |
| 64 | ||
| 65 | /* | |
| 66 | * unregister a network filesystem from the cache | |
| 67 | * - all cookies must have been released first | |
| 68 | */ | |
| 69 | void __fscache_unregister_netfs(struct fscache_netfs *netfs) | |
| 70 | { | |
| 71 | _enter("{%s.%u}", netfs->name, netfs->version); | |
| 72 | ||
| 402cb8dd | 73 | fscache_relinquish_cookie(netfs->primary_index, NULL, false); |
| ec0328e4 | 74 | pr_notice("Netfs '%s' unregistered from caching\n", netfs->name); |
| 726dd7ff DH |
75 | |
| 76 | _leave(""); | |
| 77 | } | |
| 78 | EXPORT_SYMBOL(__fscache_unregister_netfs); |