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237fead6 MH |
1 | /** |
2 | * eCryptfs: Linux filesystem encryption layer | |
3 | * | |
4 | * Copyright (C) 1997-2003 Erez Zadok | |
5 | * Copyright (C) 2001-2003 Stony Brook University | |
6 | * Copyright (C) 2004-2006 International Business Machines Corp. | |
7 | * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com> | |
8 | * Michael C. Thompson <mcthomps@us.ibm.com> | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or | |
11 | * modify it under the terms of the GNU General Public License as | |
12 | * published by the Free Software Foundation; either version 2 of the | |
13 | * License, or (at your option) any later version. | |
14 | * | |
15 | * This program is distributed in the hope that it will be useful, but | |
16 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
18 | * General Public License for more details. | |
19 | * | |
20 | * You should have received a copy of the GNU General Public License | |
21 | * along with this program; if not, write to the Free Software | |
22 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA | |
23 | * 02111-1307, USA. | |
24 | */ | |
25 | ||
26 | #include <linux/fs.h> | |
27 | #include <linux/mount.h> | |
28 | #include <linux/key.h> | |
5a0e3ad6 | 29 | #include <linux/slab.h> |
237fead6 | 30 | #include <linux/seq_file.h> |
4981e081 | 31 | #include <linux/file.h> |
237fead6 MH |
32 | #include <linux/crypto.h> |
33 | #include "ecryptfs_kernel.h" | |
34 | ||
35 | struct kmem_cache *ecryptfs_inode_info_cache; | |
36 | ||
37 | /** | |
38 | * ecryptfs_alloc_inode - allocate an ecryptfs inode | |
39 | * @sb: Pointer to the ecryptfs super block | |
40 | * | |
41 | * Called to bring an inode into existence. | |
42 | * | |
43 | * Only handle allocation, setting up structures should be done in | |
44 | * ecryptfs_read_inode. This is because the kernel, between now and | |
45 | * then, will 0 out the private data pointer. | |
46 | * | |
47 | * Returns a pointer to a newly allocated inode, NULL otherwise | |
48 | */ | |
49 | static struct inode *ecryptfs_alloc_inode(struct super_block *sb) | |
50 | { | |
035241d3 | 51 | struct ecryptfs_inode_info *inode_info; |
237fead6 MH |
52 | struct inode *inode = NULL; |
53 | ||
035241d3 MH |
54 | inode_info = kmem_cache_alloc(ecryptfs_inode_info_cache, GFP_KERNEL); |
55 | if (unlikely(!inode_info)) | |
237fead6 | 56 | goto out; |
035241d3 | 57 | ecryptfs_init_crypt_stat(&inode_info->crypt_stat); |
332ab16f TH |
58 | mutex_init(&inode_info->lower_file_mutex); |
59 | atomic_set(&inode_info->lower_file_count, 0); | |
035241d3 MH |
60 | inode_info->lower_file = NULL; |
61 | inode = &inode_info->vfs_inode; | |
237fead6 MH |
62 | out: |
63 | return inode; | |
64 | } | |
65 | ||
fa0d7e3d NP |
66 | static void ecryptfs_i_callback(struct rcu_head *head) |
67 | { | |
68 | struct inode *inode = container_of(head, struct inode, i_rcu); | |
69 | struct ecryptfs_inode_info *inode_info; | |
70 | inode_info = ecryptfs_inode_to_private(inode); | |
71 | ||
72 | INIT_LIST_HEAD(&inode->i_dentry); | |
73 | kmem_cache_free(ecryptfs_inode_info_cache, inode_info); | |
74 | } | |
75 | ||
237fead6 MH |
76 | /** |
77 | * ecryptfs_destroy_inode | |
78 | * @inode: The ecryptfs inode | |
79 | * | |
4981e081 MH |
80 | * This is used during the final destruction of the inode. All |
81 | * allocation of memory related to the inode, including allocated | |
332ab16f | 82 | * memory in the crypt_stat struct, will be released here. |
237fead6 MH |
83 | * There should be no chance that this deallocation will be missed. |
84 | */ | |
85 | static void ecryptfs_destroy_inode(struct inode *inode) | |
86 | { | |
87 | struct ecryptfs_inode_info *inode_info; | |
88 | ||
89 | inode_info = ecryptfs_inode_to_private(inode); | |
332ab16f | 90 | BUG_ON(inode_info->lower_file); |
fcd12835 | 91 | ecryptfs_destroy_crypt_stat(&inode_info->crypt_stat); |
fa0d7e3d | 92 | call_rcu(&inode->i_rcu, ecryptfs_i_callback); |
237fead6 MH |
93 | } |
94 | ||
237fead6 MH |
95 | /** |
96 | * ecryptfs_statfs | |
97 | * @sb: The ecryptfs super block | |
98 | * @buf: The struct kstatfs to fill in with stats | |
99 | * | |
100 | * Get the filesystem statistics. Currently, we let this pass right through | |
101 | * to the lower filesystem and take no action ourselves. | |
102 | */ | |
103 | static int ecryptfs_statfs(struct dentry *dentry, struct kstatfs *buf) | |
104 | { | |
ebabe9a9 CH |
105 | struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry); |
106 | ||
107 | if (!lower_dentry->d_sb->s_op->statfs) | |
108 | return -ENOSYS; | |
109 | return lower_dentry->d_sb->s_op->statfs(lower_dentry, buf); | |
237fead6 MH |
110 | } |
111 | ||
112 | /** | |
b57922d9 | 113 | * ecryptfs_evict_inode |
237fead6 MH |
114 | * @inode - The ecryptfs inode |
115 | * | |
116 | * Called by iput() when the inode reference count reached zero | |
117 | * and the inode is not hashed anywhere. Used to clear anything | |
118 | * that needs to be, before the inode is completely destroyed and put | |
119 | * on the inode free list. We use this to drop out reference to the | |
120 | * lower inode. | |
121 | */ | |
b57922d9 | 122 | static void ecryptfs_evict_inode(struct inode *inode) |
237fead6 | 123 | { |
b57922d9 AV |
124 | truncate_inode_pages(&inode->i_data, 0); |
125 | end_writeback(inode); | |
237fead6 MH |
126 | iput(ecryptfs_inode_to_lower(inode)); |
127 | } | |
128 | ||
237fead6 MH |
129 | /** |
130 | * ecryptfs_show_options | |
131 | * | |
99db6e4a ES |
132 | * Prints the mount options for a given superblock. |
133 | * Returns zero; does not fail. | |
237fead6 MH |
134 | */ |
135 | static int ecryptfs_show_options(struct seq_file *m, struct vfsmount *mnt) | |
136 | { | |
137 | struct super_block *sb = mnt->mnt_sb; | |
99db6e4a ES |
138 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat = |
139 | &ecryptfs_superblock_to_private(sb)->mount_crypt_stat; | |
140 | struct ecryptfs_global_auth_tok *walker; | |
141 | ||
142 | mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex); | |
143 | list_for_each_entry(walker, | |
144 | &mount_crypt_stat->global_auth_tok_list, | |
145 | mount_crypt_stat_list) { | |
3a5203ab TH |
146 | if (walker->flags & ECRYPTFS_AUTH_TOK_FNEK) |
147 | seq_printf(m, ",ecryptfs_fnek_sig=%s", walker->sig); | |
148 | else | |
149 | seq_printf(m, ",ecryptfs_sig=%s", walker->sig); | |
237fead6 | 150 | } |
99db6e4a ES |
151 | mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex); |
152 | ||
99db6e4a ES |
153 | seq_printf(m, ",ecryptfs_cipher=%s", |
154 | mount_crypt_stat->global_default_cipher_name); | |
155 | ||
156 | if (mount_crypt_stat->global_default_cipher_key_size) | |
157 | seq_printf(m, ",ecryptfs_key_bytes=%zd", | |
158 | mount_crypt_stat->global_default_cipher_key_size); | |
159 | if (mount_crypt_stat->flags & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED) | |
160 | seq_printf(m, ",ecryptfs_passthrough"); | |
161 | if (mount_crypt_stat->flags & ECRYPTFS_XATTR_METADATA_ENABLED) | |
162 | seq_printf(m, ",ecryptfs_xattr_metadata"); | |
163 | if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) | |
164 | seq_printf(m, ",ecryptfs_encrypted_view"); | |
e77cc8d2 TH |
165 | if (mount_crypt_stat->flags & ECRYPTFS_UNLINK_SIGS) |
166 | seq_printf(m, ",ecryptfs_unlink_sigs"); | |
8747f954 TH |
167 | if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY) |
168 | seq_printf(m, ",ecryptfs_mount_auth_tok_only"); | |
99db6e4a ES |
169 | |
170 | return 0; | |
237fead6 MH |
171 | } |
172 | ||
ee9b6d61 | 173 | const struct super_operations ecryptfs_sops = { |
237fead6 MH |
174 | .alloc_inode = ecryptfs_alloc_inode, |
175 | .destroy_inode = ecryptfs_destroy_inode, | |
57db4e8d | 176 | .drop_inode = generic_drop_inode, |
237fead6 MH |
177 | .statfs = ecryptfs_statfs, |
178 | .remount_fs = NULL, | |
b57922d9 | 179 | .evict_inode = ecryptfs_evict_inode, |
237fead6 MH |
180 | .show_options = ecryptfs_show_options |
181 | }; |