Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 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> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 29 | #include <linux/slab.h> |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 30 | #include <linux/seq_file.h> |
Michael Halcrow | 4981e08 | 2007-10-16 01:28:09 -0700 | [diff] [blame] | 31 | #include <linux/file.h> |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 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 | { |
Michael Halcrow | 035241d | 2007-10-16 01:28:12 -0700 | [diff] [blame] | 51 | struct ecryptfs_inode_info *inode_info; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 52 | struct inode *inode = NULL; |
| 53 | |
Michael Halcrow | 035241d | 2007-10-16 01:28:12 -0700 | [diff] [blame] | 54 | inode_info = kmem_cache_alloc(ecryptfs_inode_info_cache, GFP_KERNEL); |
| 55 | if (unlikely(!inode_info)) |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 56 | goto out; |
Michael Halcrow | 035241d | 2007-10-16 01:28:12 -0700 | [diff] [blame] | 57 | ecryptfs_init_crypt_stat(&inode_info->crypt_stat); |
Tyler Hicks | 332ab16 | 2011-04-14 15:35:11 -0500 | [diff] [blame] | 58 | mutex_init(&inode_info->lower_file_mutex); |
| 59 | atomic_set(&inode_info->lower_file_count, 0); |
Michael Halcrow | 035241d | 2007-10-16 01:28:12 -0700 | [diff] [blame] | 60 | inode_info->lower_file = NULL; |
| 61 | inode = &inode_info->vfs_inode; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 62 | out: |
| 63 | return inode; |
| 64 | } |
| 65 | |
Nick Piggin | fa0d7e3d | 2011-01-07 17:49:49 +1100 | [diff] [blame] | 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 | |
Nick Piggin | fa0d7e3d | 2011-01-07 17:49:49 +1100 | [diff] [blame] | 72 | kmem_cache_free(ecryptfs_inode_info_cache, inode_info); |
| 73 | } |
| 74 | |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 75 | /** |
| 76 | * ecryptfs_destroy_inode |
| 77 | * @inode: The ecryptfs inode |
| 78 | * |
Michael Halcrow | 4981e08 | 2007-10-16 01:28:09 -0700 | [diff] [blame] | 79 | * This is used during the final destruction of the inode. All |
| 80 | * allocation of memory related to the inode, including allocated |
Tyler Hicks | 332ab16 | 2011-04-14 15:35:11 -0500 | [diff] [blame] | 81 | * memory in the crypt_stat struct, will be released here. |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 82 | * There should be no chance that this deallocation will be missed. |
| 83 | */ |
| 84 | static void ecryptfs_destroy_inode(struct inode *inode) |
| 85 | { |
| 86 | struct ecryptfs_inode_info *inode_info; |
| 87 | |
| 88 | inode_info = ecryptfs_inode_to_private(inode); |
Tyler Hicks | 332ab16 | 2011-04-14 15:35:11 -0500 | [diff] [blame] | 89 | BUG_ON(inode_info->lower_file); |
Michael Halcrow | fcd1283 | 2007-10-16 01:28:01 -0700 | [diff] [blame] | 90 | ecryptfs_destroy_crypt_stat(&inode_info->crypt_stat); |
Nick Piggin | fa0d7e3d | 2011-01-07 17:49:49 +1100 | [diff] [blame] | 91 | call_rcu(&inode->i_rcu, ecryptfs_i_callback); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 92 | } |
| 93 | |
| 94 | /** |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 95 | * ecryptfs_statfs |
| 96 | * @sb: The ecryptfs super block |
| 97 | * @buf: The struct kstatfs to fill in with stats |
| 98 | * |
| 99 | * Get the filesystem statistics. Currently, we let this pass right through |
| 100 | * to the lower filesystem and take no action ourselves. |
| 101 | */ |
| 102 | static int ecryptfs_statfs(struct dentry *dentry, struct kstatfs *buf) |
| 103 | { |
Christoph Hellwig | ebabe9a | 2010-07-07 18:53:11 +0200 | [diff] [blame] | 104 | struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry); |
| 105 | |
| 106 | if (!lower_dentry->d_sb->s_op->statfs) |
| 107 | return -ENOSYS; |
| 108 | return lower_dentry->d_sb->s_op->statfs(lower_dentry, buf); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 109 | } |
| 110 | |
| 111 | /** |
Al Viro | b57922d | 2010-06-07 14:34:48 -0400 | [diff] [blame] | 112 | * ecryptfs_evict_inode |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 113 | * @inode - The ecryptfs inode |
| 114 | * |
| 115 | * Called by iput() when the inode reference count reached zero |
| 116 | * and the inode is not hashed anywhere. Used to clear anything |
| 117 | * that needs to be, before the inode is completely destroyed and put |
| 118 | * on the inode free list. We use this to drop out reference to the |
| 119 | * lower inode. |
| 120 | */ |
Al Viro | b57922d | 2010-06-07 14:34:48 -0400 | [diff] [blame] | 121 | static void ecryptfs_evict_inode(struct inode *inode) |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 122 | { |
Al Viro | b57922d | 2010-06-07 14:34:48 -0400 | [diff] [blame] | 123 | truncate_inode_pages(&inode->i_data, 0); |
| 124 | end_writeback(inode); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 125 | iput(ecryptfs_inode_to_lower(inode)); |
| 126 | } |
| 127 | |
| 128 | /** |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 129 | * ecryptfs_show_options |
| 130 | * |
Eric Sandeen | 99db6e4 | 2008-02-06 01:38:34 -0800 | [diff] [blame] | 131 | * Prints the mount options for a given superblock. |
| 132 | * Returns zero; does not fail. |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 133 | */ |
Al Viro | 34c80b1 | 2011-12-08 21:32:45 -0500 | [diff] [blame] | 134 | static int ecryptfs_show_options(struct seq_file *m, struct dentry *root) |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 135 | { |
Al Viro | 34c80b1 | 2011-12-08 21:32:45 -0500 | [diff] [blame] | 136 | struct super_block *sb = root->d_sb; |
Eric Sandeen | 99db6e4 | 2008-02-06 01:38:34 -0800 | [diff] [blame] | 137 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat = |
| 138 | &ecryptfs_superblock_to_private(sb)->mount_crypt_stat; |
| 139 | struct ecryptfs_global_auth_tok *walker; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 140 | |
Eric Sandeen | 99db6e4 | 2008-02-06 01:38:34 -0800 | [diff] [blame] | 141 | mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex); |
| 142 | list_for_each_entry(walker, |
| 143 | &mount_crypt_stat->global_auth_tok_list, |
| 144 | mount_crypt_stat_list) { |
Tyler Hicks | 3a5203a | 2009-03-16 12:35:12 -0500 | [diff] [blame] | 145 | if (walker->flags & ECRYPTFS_AUTH_TOK_FNEK) |
| 146 | seq_printf(m, ",ecryptfs_fnek_sig=%s", walker->sig); |
| 147 | else |
| 148 | seq_printf(m, ",ecryptfs_sig=%s", walker->sig); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 149 | } |
Eric Sandeen | 99db6e4 | 2008-02-06 01:38:34 -0800 | [diff] [blame] | 150 | mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex); |
| 151 | |
Eric Sandeen | 99db6e4 | 2008-02-06 01:38:34 -0800 | [diff] [blame] | 152 | seq_printf(m, ",ecryptfs_cipher=%s", |
| 153 | mount_crypt_stat->global_default_cipher_name); |
| 154 | |
| 155 | if (mount_crypt_stat->global_default_cipher_key_size) |
| 156 | seq_printf(m, ",ecryptfs_key_bytes=%zd", |
| 157 | mount_crypt_stat->global_default_cipher_key_size); |
| 158 | if (mount_crypt_stat->flags & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED) |
| 159 | seq_printf(m, ",ecryptfs_passthrough"); |
| 160 | if (mount_crypt_stat->flags & ECRYPTFS_XATTR_METADATA_ENABLED) |
| 161 | seq_printf(m, ",ecryptfs_xattr_metadata"); |
| 162 | if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) |
| 163 | seq_printf(m, ",ecryptfs_encrypted_view"); |
Tyler Hicks | e77cc8d | 2009-04-22 04:08:46 -0500 | [diff] [blame] | 164 | if (mount_crypt_stat->flags & ECRYPTFS_UNLINK_SIGS) |
| 165 | seq_printf(m, ",ecryptfs_unlink_sigs"); |
Tyler Hicks | 8747f95 | 2010-10-15 16:43:41 -0500 | [diff] [blame] | 166 | if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY) |
| 167 | seq_printf(m, ",ecryptfs_mount_auth_tok_only"); |
Eric Sandeen | 99db6e4 | 2008-02-06 01:38:34 -0800 | [diff] [blame] | 168 | |
| 169 | return 0; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 170 | } |
| 171 | |
Josef 'Jeff' Sipek | ee9b6d6 | 2007-02-12 00:55:41 -0800 | [diff] [blame] | 172 | const struct super_operations ecryptfs_sops = { |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 173 | .alloc_inode = ecryptfs_alloc_inode, |
| 174 | .destroy_inode = ecryptfs_destroy_inode, |
Thieu Le | 57db4e8 | 2011-03-08 16:26:03 -0800 | [diff] [blame] | 175 | .drop_inode = generic_drop_inode, |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 176 | .statfs = ecryptfs_statfs, |
| 177 | .remount_fs = NULL, |
Al Viro | b57922d | 2010-06-07 14:34:48 -0400 | [diff] [blame] | 178 | .evict_inode = ecryptfs_evict_inode, |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 179 | .show_options = ecryptfs_show_options |
| 180 | }; |