projects / linux.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 ([email protected]) | |
| 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 | ||
| 17 | static LIST_HEAD(fscache_netfs_list); | |
| 18 | ||
| 19 | /* | |
| 20 | * register a network filesystem for caching | |
| 21 | */ | |
| 22 | int __fscache_register_netfs(struct fscache_netfs *netfs) | |
| 23 | { | |
| 24 | struct fscache_netfs *ptr; | |
| 25 | int ret; | |
| 26 | ||
| 27 | _enter("{%s}", netfs->name); | |
| 28 | ||
| 29 | INIT_LIST_HEAD(&netfs->link); | |
| 30 | ||
| 31 | /* allocate a cookie for the primary index */ | |
| 32 | netfs->primary_index = | |
| 33 | kmem_cache_zalloc(fscache_cookie_jar, GFP_KERNEL); | |
| 34 | ||
| 35 | if (!netfs->primary_index) { | |
| 36 | _leave(" = -ENOMEM"); | |
| 37 | return -ENOMEM; | |
| 38 | } | |
| 39 | ||
| 40 | /* initialise the primary index cookie */ | |
| 41 | atomic_set(&netfs->primary_index->usage, 1); | |
| 42 | atomic_set(&netfs->primary_index->n_children, 0); | |
| 1362729b | 43 | atomic_set(&netfs->primary_index->n_active, 1); |
| 726dd7ff DH |
44 | |
| 45 | netfs->primary_index->def = &fscache_fsdef_netfs_def; | |
| 46 | netfs->primary_index->parent = &fscache_fsdef_index; | |
| 47 | netfs->primary_index->netfs_data = netfs; | |
| 94d30ae9 | 48 | netfs->primary_index->flags = 1 << FSCACHE_COOKIE_ENABLED; |
| 726dd7ff DH |
49 | |
| 50 | atomic_inc(&netfs->primary_index->parent->usage); | |
| 51 | atomic_inc(&netfs->primary_index->parent->n_children); | |
| 52 | ||
| 53 | spin_lock_init(&netfs->primary_index->lock); | |
| 54 | INIT_HLIST_HEAD(&netfs->primary_index->backing_objects); | |
| 55 | ||
| 56 | /* check the netfs type is not already present */ | |
| 57 | down_write(&fscache_addremove_sem); | |
| 58 | ||
| 59 | ret = -EEXIST; | |
| 60 | list_for_each_entry(ptr, &fscache_netfs_list, link) { | |
| 61 | if (strcmp(ptr->name, netfs->name) == 0) | |
| 62 | goto already_registered; | |
| 63 | } | |
| 64 | ||
| 65 | list_add(&netfs->link, &fscache_netfs_list); | |
| 66 | ret = 0; | |
| 67 | ||
| 36dfd116 | 68 | pr_notice("Netfs '%s' registered for caching\n", netfs->name); |
| 726dd7ff DH |
69 | |
| 70 | already_registered: | |
| 71 | up_write(&fscache_addremove_sem); | |
| 72 | ||
| 73 | if (ret < 0) { | |
| 74 | netfs->primary_index->parent = NULL; | |
| 75 | __fscache_cookie_put(netfs->primary_index); | |
| 76 | netfs->primary_index = NULL; | |
| 77 | } | |
| 78 | ||
| 79 | _leave(" = %d", ret); | |
| 80 | return ret; | |
| 81 | } | |
| 82 | EXPORT_SYMBOL(__fscache_register_netfs); | |
| 83 | ||
| 84 | /* | |
| 85 | * unregister a network filesystem from the cache | |
| 86 | * - all cookies must have been released first | |
| 87 | */ | |
| 88 | void __fscache_unregister_netfs(struct fscache_netfs *netfs) | |
| 89 | { | |
| 90 | _enter("{%s.%u}", netfs->name, netfs->version); | |
| 91 | ||
| 92 | down_write(&fscache_addremove_sem); | |
| 93 | ||
| 94 | list_del(&netfs->link); | |
| 95 | fscache_relinquish_cookie(netfs->primary_index, 0); | |
| 96 | ||
| 97 | up_write(&fscache_addremove_sem); | |
| 98 | ||
| 36dfd116 FF |
99 | pr_notice("Netfs '%s' unregistered from caching\n", |
| 100 | netfs->name); | |
| 726dd7ff DH |
101 | |
| 102 | _leave(""); | |
| 103 | } | |
| 104 | EXPORT_SYMBOL(__fscache_unregister_netfs); |