blob: 55b3145b807211102ba9477b434f3040be818e0c [file] [log] [blame]
Michael Halcrow237fead2006-10-04 02:16:22 -07001/**
2 * eCryptfs: Linux filesystem encryption layer
3 *
4 * Copyright (C) 1997-2004 Erez Zadok
5 * Copyright (C) 2001-2004 Stony Brook University
Michael Halcrowdd2a3b72007-02-12 00:53:46 -08006 * Copyright (C) 2004-2007 International Business Machines Corp.
Michael Halcrow237fead2006-10-04 02:16:22 -07007 * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
8 * Michael C. Thompsion <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/file.h>
27#include <linux/vmalloc.h>
28#include <linux/pagemap.h>
29#include <linux/dcache.h>
30#include <linux/namei.h>
31#include <linux/mount.h>
32#include <linux/crypto.h>
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -080033#include <linux/fs_stack.h>
Harvey Harrison0a688ad2008-07-23 21:30:07 -070034#include <asm/unaligned.h>
Michael Halcrow237fead2006-10-04 02:16:22 -070035#include "ecryptfs_kernel.h"
36
37static struct dentry *lock_parent(struct dentry *dentry)
38{
39 struct dentry *dir;
40
Miklos Szeredi8dc4e372008-05-12 14:02:04 -070041 dir = dget_parent(dentry);
Peter Zijlstra908e0a82007-03-07 20:41:30 -080042 mutex_lock_nested(&(dir->d_inode->i_mutex), I_MUTEX_PARENT);
Michael Halcrow237fead2006-10-04 02:16:22 -070043 return dir;
44}
45
Michael Halcrow237fead2006-10-04 02:16:22 -070046static void unlock_dir(struct dentry *dir)
47{
48 mutex_unlock(&dir->d_inode->i_mutex);
49 dput(dir);
50}
51
Michael Halcrow237fead2006-10-04 02:16:22 -070052/**
53 * ecryptfs_create_underlying_file
54 * @lower_dir_inode: inode of the parent in the lower fs of the new file
Qinghuang Fengf70f5822009-01-06 14:42:05 -080055 * @dentry: New file's dentry
Michael Halcrow237fead2006-10-04 02:16:22 -070056 * @mode: The mode of the new file
57 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
58 *
59 * Creates the file in the lower file system.
60 *
61 * Returns zero on success; non-zero on error condition
62 */
63static int
64ecryptfs_create_underlying_file(struct inode *lower_dir_inode,
65 struct dentry *dentry, int mode,
66 struct nameidata *nd)
67{
68 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
69 struct vfsmount *lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry);
70 struct dentry *dentry_save;
71 struct vfsmount *vfsmount_save;
72 int rc;
73
Jan Blunck4ac91372008-02-14 19:34:32 -080074 dentry_save = nd->path.dentry;
75 vfsmount_save = nd->path.mnt;
76 nd->path.dentry = lower_dentry;
77 nd->path.mnt = lower_mnt;
Michael Halcrow237fead2006-10-04 02:16:22 -070078 rc = vfs_create(lower_dir_inode, lower_dentry, mode, nd);
Jan Blunck4ac91372008-02-14 19:34:32 -080079 nd->path.dentry = dentry_save;
80 nd->path.mnt = vfsmount_save;
Michael Halcrow237fead2006-10-04 02:16:22 -070081 return rc;
82}
83
84/**
85 * ecryptfs_do_create
86 * @directory_inode: inode of the new file's dentry's parent in ecryptfs
87 * @ecryptfs_dentry: New file's dentry in ecryptfs
88 * @mode: The mode of the new file
89 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
90 *
91 * Creates the underlying file and the eCryptfs inode which will link to
92 * it. It will also update the eCryptfs directory inode to mimic the
93 * stat of the lower directory inode.
94 *
95 * Returns zero on success; non-zero on error condition
96 */
97static int
98ecryptfs_do_create(struct inode *directory_inode,
99 struct dentry *ecryptfs_dentry, int mode,
100 struct nameidata *nd)
101{
102 int rc;
103 struct dentry *lower_dentry;
104 struct dentry *lower_dir_dentry;
105
106 lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
107 lower_dir_dentry = lock_parent(lower_dentry);
Hirofumi Nakagawa801678c2008-04-29 01:03:09 -0700108 if (IS_ERR(lower_dir_dentry)) {
Michael Halcrow237fead2006-10-04 02:16:22 -0700109 ecryptfs_printk(KERN_ERR, "Error locking directory of "
110 "dentry\n");
111 rc = PTR_ERR(lower_dir_dentry);
112 goto out;
113 }
114 rc = ecryptfs_create_underlying_file(lower_dir_dentry->d_inode,
115 ecryptfs_dentry, mode, nd);
Michael Halcrow4981e082007-10-16 01:28:09 -0700116 if (rc) {
Michael Halcrowcaeeeec2008-01-08 15:33:02 -0800117 printk(KERN_ERR "%s: Failure to create dentry in lower fs; "
Harvey Harrison18d1dbf2008-04-29 00:59:48 -0700118 "rc = [%d]\n", __func__, rc);
Michael Halcrowcaeeeec2008-01-08 15:33:02 -0800119 goto out_lock;
Michael Halcrow237fead2006-10-04 02:16:22 -0700120 }
121 rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry,
122 directory_inode->i_sb, 0);
123 if (rc) {
124 ecryptfs_printk(KERN_ERR, "Failure in ecryptfs_interpose\n");
125 goto out_lock;
126 }
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -0800127 fsstack_copy_attr_times(directory_inode, lower_dir_dentry->d_inode);
128 fsstack_copy_inode_size(directory_inode, lower_dir_dentry->d_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700129out_lock:
130 unlock_dir(lower_dir_dentry);
131out:
132 return rc;
133}
134
135/**
136 * grow_file
Michael Halcrowd7cdc5f2007-10-16 01:28:10 -0700137 * @ecryptfs_dentry: the eCryptfs dentry
Michael Halcrow237fead2006-10-04 02:16:22 -0700138 *
139 * This is the code which will grow the file to its correct size.
140 */
Michael Halcrowd7cdc5f2007-10-16 01:28:10 -0700141static int grow_file(struct dentry *ecryptfs_dentry)
Michael Halcrow237fead2006-10-04 02:16:22 -0700142{
Michael Halcrowd7cdc5f2007-10-16 01:28:10 -0700143 struct inode *ecryptfs_inode = ecryptfs_dentry->d_inode;
Michael Halcrow237fead2006-10-04 02:16:22 -0700144 struct file fake_file;
145 struct ecryptfs_file_info tmp_file_info;
Michael Halcrowd7cdc5f2007-10-16 01:28:10 -0700146 char zero_virt[] = { 0x00 };
147 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -0700148
149 memset(&fake_file, 0, sizeof(fake_file));
Josef "Jeff" Sipekbd243a42006-12-08 02:36:48 -0800150 fake_file.f_path.dentry = ecryptfs_dentry;
Michael Halcrow237fead2006-10-04 02:16:22 -0700151 memset(&tmp_file_info, 0, sizeof(tmp_file_info));
152 ecryptfs_set_file_private(&fake_file, &tmp_file_info);
Michael Halcrowd7cdc5f2007-10-16 01:28:10 -0700153 ecryptfs_set_file_lower(
154 &fake_file,
155 ecryptfs_inode_to_private(ecryptfs_inode)->lower_file);
156 rc = ecryptfs_write(&fake_file, zero_virt, 0, 1);
157 i_size_write(ecryptfs_inode, 0);
158 rc = ecryptfs_write_inode_size_to_metadata(ecryptfs_inode);
159 ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat.flags |=
160 ECRYPTFS_NEW_FILE;
Michael Halcrow237fead2006-10-04 02:16:22 -0700161 return rc;
162}
163
164/**
165 * ecryptfs_initialize_file
166 *
167 * Cause the file to be changed from a basic empty file to an ecryptfs
168 * file with a header and first data page.
169 *
170 * Returns zero on success
171 */
172static int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry)
173{
Michael Halcrowd7cdc5f2007-10-16 01:28:10 -0700174 struct ecryptfs_crypt_stat *crypt_stat =
175 &ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat;
Michael Halcrow237fead2006-10-04 02:16:22 -0700176 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -0700177
Michael Halcrow237fead2006-10-04 02:16:22 -0700178 if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) {
179 ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
Michael Halcrowe2bd99e2007-02-12 00:53:49 -0800180 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
Michael Halcrowd7cdc5f2007-10-16 01:28:10 -0700181 goto out;
Michael Halcrow237fead2006-10-04 02:16:22 -0700182 }
Michael Halcrowe2bd99e2007-02-12 00:53:49 -0800183 crypt_stat->flags |= ECRYPTFS_NEW_FILE;
Michael Halcrow237fead2006-10-04 02:16:22 -0700184 ecryptfs_printk(KERN_DEBUG, "Initializing crypto context\n");
185 rc = ecryptfs_new_file_context(ecryptfs_dentry);
186 if (rc) {
Michael Halcrowd7cdc5f2007-10-16 01:28:10 -0700187 ecryptfs_printk(KERN_ERR, "Error creating new file "
188 "context; rc = [%d]\n", rc);
189 goto out;
Michael Halcrow237fead2006-10-04 02:16:22 -0700190 }
Michael Halcrow391b52f2008-07-23 21:30:08 -0700191 if (!ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->lower_file) {
192 rc = ecryptfs_init_persistent_file(ecryptfs_dentry);
193 if (rc) {
194 printk(KERN_ERR "%s: Error attempting to initialize "
195 "the persistent file for the dentry with name "
196 "[%s]; rc = [%d]\n", __func__,
197 ecryptfs_dentry->d_name.name, rc);
198 goto out;
199 }
200 }
Michael Halcrowd7cdc5f2007-10-16 01:28:10 -0700201 rc = ecryptfs_write_metadata(ecryptfs_dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -0700202 if (rc) {
Michael Halcrowd7cdc5f2007-10-16 01:28:10 -0700203 printk(KERN_ERR "Error writing headers; rc = [%d]\n", rc);
204 goto out;
Michael Halcrow237fead2006-10-04 02:16:22 -0700205 }
Michael Halcrowd7cdc5f2007-10-16 01:28:10 -0700206 rc = grow_file(ecryptfs_dentry);
Michael Halcrow5dda6992007-10-16 01:28:06 -0700207 if (rc)
Michael Halcrowd7cdc5f2007-10-16 01:28:10 -0700208 printk(KERN_ERR "Error growing file; rc = [%d]\n", rc);
Michael Halcrow237fead2006-10-04 02:16:22 -0700209out:
210 return rc;
211}
212
213/**
214 * ecryptfs_create
215 * @dir: The inode of the directory in which to create the file.
216 * @dentry: The eCryptfs dentry
217 * @mode: The mode of the new file.
218 * @nd: nameidata
219 *
220 * Creates a new file.
221 *
222 * Returns zero on success; non-zero on error condition
223 */
224static int
225ecryptfs_create(struct inode *directory_inode, struct dentry *ecryptfs_dentry,
226 int mode, struct nameidata *nd)
227{
228 int rc;
229
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800230 /* ecryptfs_do_create() calls ecryptfs_interpose() */
Michael Halcrow237fead2006-10-04 02:16:22 -0700231 rc = ecryptfs_do_create(directory_inode, ecryptfs_dentry, mode, nd);
232 if (unlikely(rc)) {
233 ecryptfs_printk(KERN_WARNING, "Failed to create file in"
234 "lower filesystem\n");
235 goto out;
236 }
237 /* At this point, a file exists on "disk"; we need to make sure
238 * that this on disk file is prepared to be an ecryptfs file */
239 rc = ecryptfs_initialize_file(ecryptfs_dentry);
240out:
241 return rc;
242}
243
244/**
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800245 * ecryptfs_lookup_and_interpose_lower - Perform a lookup
Michael Halcrow237fead2006-10-04 02:16:22 -0700246 */
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800247int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
248 struct dentry *lower_dentry,
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800249 struct inode *ecryptfs_dir_inode,
250 struct nameidata *ecryptfs_nd)
Michael Halcrow237fead2006-10-04 02:16:22 -0700251{
Michael Halcrow237fead2006-10-04 02:16:22 -0700252 struct dentry *lower_dir_dentry;
Michael Halcrow237fead2006-10-04 02:16:22 -0700253 struct vfsmount *lower_mnt;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800254 struct inode *lower_inode;
Michael Halcrowe77a56d2007-02-12 00:53:47 -0800255 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
Tyler Hicks2aac0cf2009-03-20 02:23:57 -0500256 struct ecryptfs_crypt_stat *crypt_stat;
Michael Halcrow237fead2006-10-04 02:16:22 -0700257 char *page_virt = NULL;
Michael Halcrow237fead2006-10-04 02:16:22 -0700258 u64 file_size;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800259 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -0700260
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800261 lower_dir_dentry = lower_dentry->d_parent;
262 lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(
263 ecryptfs_dentry->d_parent));
Michael Halcrow237fead2006-10-04 02:16:22 -0700264 lower_inode = lower_dentry->d_inode;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800265 fsstack_copy_attr_atime(ecryptfs_dir_inode, lower_dir_dentry->d_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700266 BUG_ON(!atomic_read(&lower_dentry->d_count));
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800267 ecryptfs_set_dentry_private(ecryptfs_dentry,
Michael Halcrow237fead2006-10-04 02:16:22 -0700268 kmem_cache_alloc(ecryptfs_dentry_info_cache,
Christoph Lametere94b1762006-12-06 20:33:17 -0800269 GFP_KERNEL));
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800270 if (!ecryptfs_dentry_to_private(ecryptfs_dentry)) {
Michael Halcrow237fead2006-10-04 02:16:22 -0700271 rc = -ENOMEM;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800272 printk(KERN_ERR "%s: Out of memory whilst attempting "
273 "to allocate ecryptfs_dentry_info struct\n",
274 __func__);
Michael Halcrow237fead2006-10-04 02:16:22 -0700275 goto out_dput;
276 }
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800277 ecryptfs_set_dentry_lower(ecryptfs_dentry, lower_dentry);
278 ecryptfs_set_dentry_lower_mnt(ecryptfs_dentry, lower_mnt);
Michael Halcrow237fead2006-10-04 02:16:22 -0700279 if (!lower_dentry->d_inode) {
280 /* We want to add because we couldn't find in lower */
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800281 d_add(ecryptfs_dentry, NULL);
Michael Halcrow237fead2006-10-04 02:16:22 -0700282 goto out;
283 }
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800284 rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry,
285 ecryptfs_dir_inode->i_sb, 1);
Michael Halcrow237fead2006-10-04 02:16:22 -0700286 if (rc) {
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800287 printk(KERN_ERR "%s: Error interposing; rc = [%d]\n",
288 __func__, rc);
Michael Halcrow391b52f2008-07-23 21:30:08 -0700289 goto out;
Michael Halcrow237fead2006-10-04 02:16:22 -0700290 }
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800291 if (S_ISDIR(lower_inode->i_mode))
Michael Halcrow237fead2006-10-04 02:16:22 -0700292 goto out;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800293 if (S_ISLNK(lower_inode->i_mode))
Michael Halcrow237fead2006-10-04 02:16:22 -0700294 goto out;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800295 if (special_file(lower_inode->i_mode))
Ryusuke Konishi202a21d2007-08-10 13:00:51 -0700296 goto out;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800297 if (!ecryptfs_nd)
Michael Halcrow237fead2006-10-04 02:16:22 -0700298 goto out;
Michael Halcrow237fead2006-10-04 02:16:22 -0700299 /* Released in this function */
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800300 page_virt = kmem_cache_zalloc(ecryptfs_header_cache_2, GFP_USER);
Michael Halcrow237fead2006-10-04 02:16:22 -0700301 if (!page_virt) {
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800302 printk(KERN_ERR "%s: Cannot kmem_cache_zalloc() a page\n",
303 __func__);
Michael Halcrow237fead2006-10-04 02:16:22 -0700304 rc = -ENOMEM;
Michael Halcrow391b52f2008-07-23 21:30:08 -0700305 goto out;
Michael Halcrow237fead2006-10-04 02:16:22 -0700306 }
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800307 if (!ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->lower_file) {
308 rc = ecryptfs_init_persistent_file(ecryptfs_dentry);
Michael Halcrow391b52f2008-07-23 21:30:08 -0700309 if (rc) {
310 printk(KERN_ERR "%s: Error attempting to initialize "
311 "the persistent file for the dentry with name "
312 "[%s]; rc = [%d]\n", __func__,
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800313 ecryptfs_dentry->d_name.name, rc);
314 goto out_free_kmem;
Michael Halcrow391b52f2008-07-23 21:30:08 -0700315 }
316 }
Tyler Hicks2aac0cf2009-03-20 02:23:57 -0500317 crypt_stat = &ecryptfs_inode_to_private(
318 ecryptfs_dentry->d_inode)->crypt_stat;
319 /* TODO: lock for crypt_stat comparison */
320 if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED))
321 ecryptfs_set_default_sizes(crypt_stat);
Michael Halcrowd7cdc5f2007-10-16 01:28:10 -0700322 rc = ecryptfs_read_and_validate_header_region(page_virt,
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800323 ecryptfs_dentry->d_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700324 if (rc) {
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800325 rc = ecryptfs_read_and_validate_xattr_region(page_virt,
326 ecryptfs_dentry);
Michael Halcrowdd2a3b72007-02-12 00:53:46 -0800327 if (rc) {
Michael Halcrowdd2a3b72007-02-12 00:53:46 -0800328 rc = 0;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800329 goto out_free_kmem;
Michael Halcrow237fead2006-10-04 02:16:22 -0700330 }
Michael Halcrowdd2a3b72007-02-12 00:53:46 -0800331 crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
Michael Halcrow237fead2006-10-04 02:16:22 -0700332 }
Michael Halcrowe77a56d2007-02-12 00:53:47 -0800333 mount_crypt_stat = &ecryptfs_superblock_to_private(
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800334 ecryptfs_dentry->d_sb)->mount_crypt_stat;
Michael Halcrowe77a56d2007-02-12 00:53:47 -0800335 if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) {
336 if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
Michael Halcrowcc11bef2008-02-06 01:38:32 -0800337 file_size = (crypt_stat->num_header_bytes_at_front
Michael Halcrowe77a56d2007-02-12 00:53:47 -0800338 + i_size_read(lower_dentry->d_inode));
339 else
340 file_size = i_size_read(lower_dentry->d_inode);
341 } else {
Harvey Harrison0a688ad2008-07-23 21:30:07 -0700342 file_size = get_unaligned_be64(page_virt);
Michael Halcrowe77a56d2007-02-12 00:53:47 -0800343 }
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800344 i_size_write(ecryptfs_dentry->d_inode, (loff_t)file_size);
345out_free_kmem:
Michael Halcrow237fead2006-10-04 02:16:22 -0700346 kmem_cache_free(ecryptfs_header_cache_2, page_virt);
347 goto out;
Michael Halcrow237fead2006-10-04 02:16:22 -0700348out_dput:
349 dput(lower_dentry);
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800350 d_drop(ecryptfs_dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -0700351out:
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800352 return rc;
353}
354
355/**
356 * ecryptfs_lookup
357 * @ecryptfs_dir_inode: The eCryptfs directory inode
358 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
359 * @ecryptfs_nd: nameidata; may be NULL
360 *
361 * Find a file on disk. If the file does not exist, then we'll add it to the
362 * dentry cache and continue on to read it from the disk.
363 */
364static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
365 struct dentry *ecryptfs_dentry,
366 struct nameidata *ecryptfs_nd)
367{
368 char *encrypted_and_encoded_name = NULL;
Michael Halcrowa8f12862009-01-06 14:42:03 -0800369 size_t encrypted_and_encoded_name_size;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800370 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800371 struct dentry *lower_dir_dentry, *lower_dentry;
372 int rc = 0;
373
374 ecryptfs_dentry->d_op = &ecryptfs_dops;
375 if ((ecryptfs_dentry->d_name.len == 1
376 && !strcmp(ecryptfs_dentry->d_name.name, "."))
377 || (ecryptfs_dentry->d_name.len == 2
378 && !strcmp(ecryptfs_dentry->d_name.name, ".."))) {
379 goto out_d_drop;
380 }
381 lower_dir_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry->d_parent);
382 lower_dentry = lookup_one_len(ecryptfs_dentry->d_name.name,
383 lower_dir_dentry,
384 ecryptfs_dentry->d_name.len);
385 if (IS_ERR(lower_dentry)) {
386 rc = PTR_ERR(lower_dentry);
387 printk(KERN_ERR "%s: lookup_one_len() returned [%d] on "
388 "lower_dentry = [%s]\n", __func__, rc,
389 ecryptfs_dentry->d_name.name);
390 goto out_d_drop;
391 }
392 if (lower_dentry->d_inode)
393 goto lookup_and_interpose;
Tyler Hicks2aac0cf2009-03-20 02:23:57 -0500394 mount_crypt_stat = &ecryptfs_superblock_to_private(
395 ecryptfs_dentry->d_sb)->mount_crypt_stat;
396 if (!(mount_crypt_stat
397 && (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)))
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800398 goto lookup_and_interpose;
399 dput(lower_dentry);
400 rc = ecryptfs_encrypt_and_encode_filename(
401 &encrypted_and_encoded_name, &encrypted_and_encoded_name_size,
Tyler Hicks2aac0cf2009-03-20 02:23:57 -0500402 NULL, mount_crypt_stat, ecryptfs_dentry->d_name.name,
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800403 ecryptfs_dentry->d_name.len);
404 if (rc) {
405 printk(KERN_ERR "%s: Error attempting to encrypt and encode "
406 "filename; rc = [%d]\n", __func__, rc);
407 goto out_d_drop;
408 }
409 lower_dentry = lookup_one_len(encrypted_and_encoded_name,
410 lower_dir_dentry,
411 encrypted_and_encoded_name_size - 1);
412 if (IS_ERR(lower_dentry)) {
413 rc = PTR_ERR(lower_dentry);
414 printk(KERN_ERR "%s: lookup_one_len() returned [%d] on "
415 "lower_dentry = [%s]\n", __func__, rc,
416 encrypted_and_encoded_name);
417 goto out_d_drop;
418 }
419lookup_and_interpose:
420 rc = ecryptfs_lookup_and_interpose_lower(ecryptfs_dentry, lower_dentry,
Tyler Hicks2aac0cf2009-03-20 02:23:57 -0500421 ecryptfs_dir_inode,
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800422 ecryptfs_nd);
423 goto out;
424out_d_drop:
425 d_drop(ecryptfs_dentry);
426out:
427 kfree(encrypted_and_encoded_name);
Michael Halcrow237fead2006-10-04 02:16:22 -0700428 return ERR_PTR(rc);
429}
430
431static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
432 struct dentry *new_dentry)
433{
434 struct dentry *lower_old_dentry;
435 struct dentry *lower_new_dentry;
436 struct dentry *lower_dir_dentry;
437 u64 file_size_save;
438 int rc;
439
440 file_size_save = i_size_read(old_dentry->d_inode);
441 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
442 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
443 dget(lower_old_dentry);
444 dget(lower_new_dentry);
445 lower_dir_dentry = lock_parent(lower_new_dentry);
446 rc = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode,
447 lower_new_dentry);
448 if (rc || !lower_new_dentry->d_inode)
449 goto out_lock;
450 rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb, 0);
451 if (rc)
452 goto out_lock;
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -0800453 fsstack_copy_attr_times(dir, lower_new_dentry->d_inode);
454 fsstack_copy_inode_size(dir, lower_new_dentry->d_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700455 old_dentry->d_inode->i_nlink =
456 ecryptfs_inode_to_lower(old_dentry->d_inode)->i_nlink;
457 i_size_write(new_dentry->d_inode, file_size_save);
458out_lock:
459 unlock_dir(lower_dir_dentry);
460 dput(lower_new_dentry);
461 dput(lower_old_dentry);
Michael Halcrowae56fb12006-11-16 01:19:30 -0800462 d_drop(lower_old_dentry);
Michael Halcrow45ec4aba2006-10-30 22:07:20 -0800463 d_drop(new_dentry);
464 d_drop(old_dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -0700465 return rc;
466}
467
468static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
469{
470 int rc = 0;
471 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
472 struct inode *lower_dir_inode = ecryptfs_inode_to_lower(dir);
Miklos Szeredi8dc4e372008-05-12 14:02:04 -0700473 struct dentry *lower_dir_dentry;
Michael Halcrow237fead2006-10-04 02:16:22 -0700474
Miklos Szeredi8dc4e372008-05-12 14:02:04 -0700475 lower_dir_dentry = lock_parent(lower_dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -0700476 rc = vfs_unlink(lower_dir_inode, lower_dentry);
477 if (rc) {
Michael Halcrowae56fb12006-11-16 01:19:30 -0800478 printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc);
Michael Halcrow237fead2006-10-04 02:16:22 -0700479 goto out_unlock;
480 }
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -0800481 fsstack_copy_attr_times(dir, lower_dir_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700482 dentry->d_inode->i_nlink =
483 ecryptfs_inode_to_lower(dentry->d_inode)->i_nlink;
484 dentry->d_inode->i_ctime = dir->i_ctime;
Michael Halcrowcaeeeec2008-01-08 15:33:02 -0800485 d_drop(dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -0700486out_unlock:
Miklos Szeredi8dc4e372008-05-12 14:02:04 -0700487 unlock_dir(lower_dir_dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -0700488 return rc;
489}
490
491static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry,
492 const char *symname)
493{
494 int rc;
495 struct dentry *lower_dentry;
496 struct dentry *lower_dir_dentry;
Michael Halcrow237fead2006-10-04 02:16:22 -0700497 char *encoded_symname;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800498 size_t encoded_symlen;
499 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
Michael Halcrow237fead2006-10-04 02:16:22 -0700500
501 lower_dentry = ecryptfs_dentry_to_lower(dentry);
502 dget(lower_dentry);
503 lower_dir_dentry = lock_parent(lower_dentry);
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800504 mount_crypt_stat = &ecryptfs_superblock_to_private(
505 dir->i_sb)->mount_crypt_stat;
506 rc = ecryptfs_encrypt_and_encode_filename(&encoded_symname,
507 &encoded_symlen,
508 NULL,
509 mount_crypt_stat, symname,
510 strlen(symname));
511 if (rc)
Michael Halcrow237fead2006-10-04 02:16:22 -0700512 goto out_lock;
Michael Halcrow237fead2006-10-04 02:16:22 -0700513 rc = vfs_symlink(lower_dir_dentry->d_inode, lower_dentry,
Miklos Szeredidb2e7472008-06-24 16:50:16 +0200514 encoded_symname);
Michael Halcrow237fead2006-10-04 02:16:22 -0700515 kfree(encoded_symname);
516 if (rc || !lower_dentry->d_inode)
517 goto out_lock;
518 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
519 if (rc)
520 goto out_lock;
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -0800521 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
522 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700523out_lock:
524 unlock_dir(lower_dir_dentry);
525 dput(lower_dentry);
526 if (!dentry->d_inode)
527 d_drop(dentry);
528 return rc;
529}
530
531static int ecryptfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
532{
533 int rc;
534 struct dentry *lower_dentry;
535 struct dentry *lower_dir_dentry;
536
537 lower_dentry = ecryptfs_dentry_to_lower(dentry);
538 lower_dir_dentry = lock_parent(lower_dentry);
539 rc = vfs_mkdir(lower_dir_dentry->d_inode, lower_dentry, mode);
540 if (rc || !lower_dentry->d_inode)
541 goto out;
542 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
543 if (rc)
544 goto out;
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -0800545 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
546 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700547 dir->i_nlink = lower_dir_dentry->d_inode->i_nlink;
548out:
549 unlock_dir(lower_dir_dentry);
550 if (!dentry->d_inode)
551 d_drop(dentry);
552 return rc;
553}
554
555static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
556{
Michael Halcrow237fead2006-10-04 02:16:22 -0700557 struct dentry *lower_dentry;
Michael Halcrow237fead2006-10-04 02:16:22 -0700558 struct dentry *lower_dir_dentry;
Michael Halcrow45ec4aba2006-10-30 22:07:20 -0800559 int rc;
Michael Halcrow237fead2006-10-04 02:16:22 -0700560
561 lower_dentry = ecryptfs_dentry_to_lower(dentry);
Michael Halcrow45ec4aba2006-10-30 22:07:20 -0800562 dget(dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -0700563 lower_dir_dentry = lock_parent(lower_dentry);
Michael Halcrow45ec4aba2006-10-30 22:07:20 -0800564 dget(lower_dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -0700565 rc = vfs_rmdir(lower_dir_dentry->d_inode, lower_dentry);
Michael Halcrow45ec4aba2006-10-30 22:07:20 -0800566 dput(lower_dentry);
567 if (!rc)
568 d_delete(lower_dentry);
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -0800569 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700570 dir->i_nlink = lower_dir_dentry->d_inode->i_nlink;
571 unlock_dir(lower_dir_dentry);
572 if (!rc)
573 d_drop(dentry);
Michael Halcrow45ec4aba2006-10-30 22:07:20 -0800574 dput(dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -0700575 return rc;
576}
577
578static int
579ecryptfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
580{
581 int rc;
582 struct dentry *lower_dentry;
583 struct dentry *lower_dir_dentry;
584
585 lower_dentry = ecryptfs_dentry_to_lower(dentry);
586 lower_dir_dentry = lock_parent(lower_dentry);
587 rc = vfs_mknod(lower_dir_dentry->d_inode, lower_dentry, mode, dev);
588 if (rc || !lower_dentry->d_inode)
589 goto out;
Michael Halcrow391b52f2008-07-23 21:30:08 -0700590 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
Michael Halcrow237fead2006-10-04 02:16:22 -0700591 if (rc)
592 goto out;
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -0800593 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
594 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700595out:
596 unlock_dir(lower_dir_dentry);
597 if (!dentry->d_inode)
598 d_drop(dentry);
599 return rc;
600}
601
602static int
603ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
604 struct inode *new_dir, struct dentry *new_dentry)
605{
606 int rc;
607 struct dentry *lower_old_dentry;
608 struct dentry *lower_new_dentry;
609 struct dentry *lower_old_dir_dentry;
610 struct dentry *lower_new_dir_dentry;
611
612 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
613 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
614 dget(lower_old_dentry);
615 dget(lower_new_dentry);
616 lower_old_dir_dentry = dget_parent(lower_old_dentry);
617 lower_new_dir_dentry = dget_parent(lower_new_dentry);
618 lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
619 rc = vfs_rename(lower_old_dir_dentry->d_inode, lower_old_dentry,
620 lower_new_dir_dentry->d_inode, lower_new_dentry);
621 if (rc)
622 goto out_lock;
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -0800623 fsstack_copy_attr_all(new_dir, lower_new_dir_dentry->d_inode, NULL);
Michael Halcrow237fead2006-10-04 02:16:22 -0700624 if (new_dir != old_dir)
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -0800625 fsstack_copy_attr_all(old_dir, lower_old_dir_dentry->d_inode, NULL);
Michael Halcrow237fead2006-10-04 02:16:22 -0700626out_lock:
627 unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
Michael Halcrowa9083082006-11-16 01:19:16 -0800628 dput(lower_new_dentry->d_parent);
629 dput(lower_old_dentry->d_parent);
Michael Halcrow237fead2006-10-04 02:16:22 -0700630 dput(lower_new_dentry);
631 dput(lower_old_dentry);
632 return rc;
633}
634
635static int
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800636ecryptfs_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
Michael Halcrow237fead2006-10-04 02:16:22 -0700637{
Michael Halcrow237fead2006-10-04 02:16:22 -0700638 char *lower_buf;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800639 struct dentry *lower_dentry;
Michael Halcrow237fead2006-10-04 02:16:22 -0700640 struct ecryptfs_crypt_stat *crypt_stat;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800641 char *plaintext_name;
642 size_t plaintext_name_size;
643 mm_segment_t old_fs;
644 int rc;
Michael Halcrow237fead2006-10-04 02:16:22 -0700645
646 lower_dentry = ecryptfs_dentry_to_lower(dentry);
Al Viroacfa4382008-12-04 10:06:33 -0500647 if (!lower_dentry->d_inode->i_op->readlink) {
Michael Halcrow237fead2006-10-04 02:16:22 -0700648 rc = -EINVAL;
649 goto out;
650 }
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800651 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
Michael Halcrow237fead2006-10-04 02:16:22 -0700652 /* Released in this function */
653 lower_buf = kmalloc(bufsiz, GFP_KERNEL);
654 if (lower_buf == NULL) {
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800655 printk(KERN_ERR "%s: Out of memory whilst attempting to "
656 "kmalloc [%d] bytes\n", __func__, bufsiz);
Michael Halcrow237fead2006-10-04 02:16:22 -0700657 rc = -ENOMEM;
658 goto out;
659 }
660 old_fs = get_fs();
661 set_fs(get_ds());
Michael Halcrow237fead2006-10-04 02:16:22 -0700662 rc = lower_dentry->d_inode->i_op->readlink(lower_dentry,
663 (char __user *)lower_buf,
664 bufsiz);
665 set_fs(old_fs);
666 if (rc >= 0) {
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800667 rc = ecryptfs_decode_and_decrypt_filename(&plaintext_name,
668 &plaintext_name_size,
669 dentry, lower_buf,
670 rc);
671 if (rc) {
672 printk(KERN_ERR "%s: Error attempting to decode and "
673 "decrypt filename; rc = [%d]\n", __func__,
674 rc);
Michael Halcrow237fead2006-10-04 02:16:22 -0700675 goto out_free_lower_buf;
Michael Halcrow237fead2006-10-04 02:16:22 -0700676 }
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800677 rc = copy_to_user(buf, plaintext_name, plaintext_name_size);
678 if (rc)
679 rc = -EFAULT;
680 else
681 rc = plaintext_name_size;
682 kfree(plaintext_name);
683 fsstack_copy_attr_atime(dentry->d_inode, lower_dentry->d_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700684 }
685out_free_lower_buf:
686 kfree(lower_buf);
687out:
688 return rc;
689}
690
691static void *ecryptfs_follow_link(struct dentry *dentry, struct nameidata *nd)
692{
693 char *buf;
694 int len = PAGE_SIZE, rc;
695 mm_segment_t old_fs;
696
697 /* Released in ecryptfs_put_link(); only release here on error */
698 buf = kmalloc(len, GFP_KERNEL);
699 if (!buf) {
700 rc = -ENOMEM;
701 goto out;
702 }
703 old_fs = get_fs();
704 set_fs(get_ds());
Michael Halcrow237fead2006-10-04 02:16:22 -0700705 rc = dentry->d_inode->i_op->readlink(dentry, (char __user *)buf, len);
Michael Halcrow237fead2006-10-04 02:16:22 -0700706 set_fs(old_fs);
707 if (rc < 0)
708 goto out_free;
Duane Griffina17d5232008-12-19 20:47:10 +0000709 else
710 buf[rc] = '\0';
Michael Halcrow237fead2006-10-04 02:16:22 -0700711 rc = 0;
712 nd_set_link(nd, buf);
713 goto out;
714out_free:
715 kfree(buf);
716out:
717 return ERR_PTR(rc);
718}
719
720static void
721ecryptfs_put_link(struct dentry *dentry, struct nameidata *nd, void *ptr)
722{
723 /* Free the char* */
724 kfree(nd_get_link(nd));
725}
726
727/**
728 * upper_size_to_lower_size
729 * @crypt_stat: Crypt_stat associated with file
730 * @upper_size: Size of the upper file
731 *
Michael Halcrowcc11bef2008-02-06 01:38:32 -0800732 * Calculate the required size of the lower file based on the
Michael Halcrow237fead2006-10-04 02:16:22 -0700733 * specified size of the upper file. This calculation is based on the
734 * number of headers in the underlying file and the extent size.
735 *
736 * Returns Calculated size of the lower file.
737 */
738static loff_t
739upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
740 loff_t upper_size)
741{
742 loff_t lower_size;
743
Michael Halcrowcc11bef2008-02-06 01:38:32 -0800744 lower_size = crypt_stat->num_header_bytes_at_front;
Michael Halcrow237fead2006-10-04 02:16:22 -0700745 if (upper_size != 0) {
746 loff_t num_extents;
747
748 num_extents = upper_size >> crypt_stat->extent_shift;
749 if (upper_size & ~crypt_stat->extent_mask)
750 num_extents++;
751 lower_size += (num_extents * crypt_stat->extent_size);
752 }
753 return lower_size;
754}
755
756/**
757 * ecryptfs_truncate
758 * @dentry: The ecryptfs layer dentry
759 * @new_length: The length to expand the file to
760 *
761 * Function to handle truncations modifying the size of the file. Note
762 * that the file sizes are interpolated. When expanding, we are simply
763 * writing strings of 0's out. When truncating, we need to modify the
764 * underlying file size according to the page index interpolations.
765 *
766 * Returns zero on success; non-zero otherwise
767 */
768int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
769{
770 int rc = 0;
771 struct inode *inode = dentry->d_inode;
772 struct dentry *lower_dentry;
Michael Halcrow2ed92552007-10-16 01:28:10 -0700773 struct file fake_ecryptfs_file;
Michael Halcrow237fead2006-10-04 02:16:22 -0700774 struct ecryptfs_crypt_stat *crypt_stat;
775 loff_t i_size = i_size_read(inode);
776 loff_t lower_size_before_truncate;
777 loff_t lower_size_after_truncate;
778
779 if (unlikely((new_length == i_size)))
780 goto out;
781 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
782 /* Set up a fake ecryptfs file, this is used to interface with
783 * the file in the underlying filesystem so that the
784 * truncation has an effect there as well. */
785 memset(&fake_ecryptfs_file, 0, sizeof(fake_ecryptfs_file));
Josef "Jeff" Sipekbd243a42006-12-08 02:36:48 -0800786 fake_ecryptfs_file.f_path.dentry = dentry;
Michael Halcrow237fead2006-10-04 02:16:22 -0700787 /* Released at out_free: label */
788 ecryptfs_set_file_private(&fake_ecryptfs_file,
789 kmem_cache_alloc(ecryptfs_file_info_cache,
Christoph Lametere94b1762006-12-06 20:33:17 -0800790 GFP_KERNEL));
Michael Halcrow237fead2006-10-04 02:16:22 -0700791 if (unlikely(!ecryptfs_file_to_private(&fake_ecryptfs_file))) {
792 rc = -ENOMEM;
793 goto out;
794 }
795 lower_dentry = ecryptfs_dentry_to_lower(dentry);
Michael Halcrow2ed92552007-10-16 01:28:10 -0700796 ecryptfs_set_file_lower(
797 &fake_ecryptfs_file,
798 ecryptfs_inode_to_private(dentry->d_inode)->lower_file);
Michael Halcrow237fead2006-10-04 02:16:22 -0700799 /* Switch on growing or shrinking file */
800 if (new_length > i_size) {
Michael Halcrow2ed92552007-10-16 01:28:10 -0700801 char zero[] = { 0x00 };
Michael Halcrow240e2df2007-06-27 14:09:44 -0700802
Michael Halcrow2ed92552007-10-16 01:28:10 -0700803 /* Write a single 0 at the last position of the file;
804 * this triggers code that will fill in 0's throughout
805 * the intermediate portion of the previous end of the
806 * file and the new and of the file */
807 rc = ecryptfs_write(&fake_ecryptfs_file, zero,
808 (new_length - 1), 1);
809 } else { /* new_length < i_size_read(inode) */
810 /* We're chopping off all the pages down do the page
811 * in which new_length is located. Fill in the end of
812 * that page from (new_length & ~PAGE_CACHE_MASK) to
813 * PAGE_CACHE_SIZE with zeros. */
814 size_t num_zeros = (PAGE_CACHE_SIZE
815 - (new_length & ~PAGE_CACHE_MASK));
816
817 if (num_zeros) {
818 char *zeros_virt;
819
820 zeros_virt = kzalloc(num_zeros, GFP_KERNEL);
821 if (!zeros_virt) {
822 rc = -ENOMEM;
823 goto out_free;
824 }
825 rc = ecryptfs_write(&fake_ecryptfs_file, zeros_virt,
826 new_length, num_zeros);
827 kfree(zeros_virt);
Michael Halcrow5dda6992007-10-16 01:28:06 -0700828 if (rc) {
Michael Halcrow240e2df2007-06-27 14:09:44 -0700829 printk(KERN_ERR "Error attempting to zero out "
830 "the remainder of the end page on "
831 "reducing truncate; rc = [%d]\n", rc);
Michael Halcrow2ed92552007-10-16 01:28:10 -0700832 goto out_free;
Michael Halcrow240e2df2007-06-27 14:09:44 -0700833 }
834 }
Michael Halcrow237fead2006-10-04 02:16:22 -0700835 vmtruncate(inode, new_length);
Michael Halcrow0216f7f2007-10-16 01:28:08 -0700836 rc = ecryptfs_write_inode_size_to_metadata(inode);
Michael Halcrowdd2a3b72007-02-12 00:53:46 -0800837 if (rc) {
838 printk(KERN_ERR "Problem with "
839 "ecryptfs_write_inode_size_to_metadata; "
840 "rc = [%d]\n", rc);
Michael Halcrow2ed92552007-10-16 01:28:10 -0700841 goto out_free;
Michael Halcrowdd2a3b72007-02-12 00:53:46 -0800842 }
Michael Halcrow237fead2006-10-04 02:16:22 -0700843 /* We are reducing the size of the ecryptfs file, and need to
844 * know if we need to reduce the size of the lower file. */
845 lower_size_before_truncate =
846 upper_size_to_lower_size(crypt_stat, i_size);
847 lower_size_after_truncate =
848 upper_size_to_lower_size(crypt_stat, new_length);
849 if (lower_size_after_truncate < lower_size_before_truncate)
850 vmtruncate(lower_dentry->d_inode,
851 lower_size_after_truncate);
852 }
Michael Halcrow237fead2006-10-04 02:16:22 -0700853out_free:
854 if (ecryptfs_file_to_private(&fake_ecryptfs_file))
855 kmem_cache_free(ecryptfs_file_info_cache,
856 ecryptfs_file_to_private(&fake_ecryptfs_file));
857out:
858 return rc;
859}
860
861static int
Al Viroe6305c42008-07-15 21:03:57 -0400862ecryptfs_permission(struct inode *inode, int mask)
Michael Halcrow237fead2006-10-04 02:16:22 -0700863{
Al Virof419a2e2008-07-22 00:07:17 -0400864 return inode_permission(ecryptfs_inode_to_lower(inode), mask);
Michael Halcrow237fead2006-10-04 02:16:22 -0700865}
866
867/**
868 * ecryptfs_setattr
869 * @dentry: dentry handle to the inode to modify
870 * @ia: Structure with flags of what to change and values
871 *
872 * Updates the metadata of an inode. If the update is to the size
873 * i.e. truncation, then ecryptfs_truncate will handle the size modification
874 * of both the ecryptfs inode and the lower inode.
875 *
876 * All other metadata changes will be passed right to the lower filesystem,
877 * and we will just update our inode to look like the lower.
878 */
879static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
880{
881 int rc = 0;
882 struct dentry *lower_dentry;
883 struct inode *inode;
884 struct inode *lower_inode;
885 struct ecryptfs_crypt_stat *crypt_stat;
886
887 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
Michael Halcrowe10f2812007-06-27 14:09:44 -0700888 if (!(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED))
889 ecryptfs_init_crypt_stat(crypt_stat);
Michael Halcrow237fead2006-10-04 02:16:22 -0700890 inode = dentry->d_inode;
891 lower_inode = ecryptfs_inode_to_lower(inode);
Michael Halcrowe10f2812007-06-27 14:09:44 -0700892 lower_dentry = ecryptfs_dentry_to_lower(dentry);
893 mutex_lock(&crypt_stat->cs_mutex);
894 if (S_ISDIR(dentry->d_inode->i_mode))
895 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
Michael Halcrow64ee4802007-07-19 01:47:54 -0700896 else if (S_ISREG(dentry->d_inode->i_mode)
897 && (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
898 || !(crypt_stat->flags & ECRYPTFS_KEY_VALID))) {
Michael Halcrowe10f2812007-06-27 14:09:44 -0700899 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
Michael Halcrowe10f2812007-06-27 14:09:44 -0700900
Michael Halcrowe10f2812007-06-27 14:09:44 -0700901 mount_crypt_stat = &ecryptfs_superblock_to_private(
902 dentry->d_sb)->mount_crypt_stat;
Michael Halcrowd7cdc5f2007-10-16 01:28:10 -0700903 rc = ecryptfs_read_metadata(dentry);
Michael Halcrow5dda6992007-10-16 01:28:06 -0700904 if (rc) {
Michael Halcrowe10f2812007-06-27 14:09:44 -0700905 if (!(mount_crypt_stat->flags
906 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
907 rc = -EIO;
Michael Halcrow25bd8172008-02-06 01:38:35 -0800908 printk(KERN_WARNING "Either the lower file "
Michael Halcrowe10f2812007-06-27 14:09:44 -0700909 "is not in a valid eCryptfs format, "
Michael Halcrow25bd8172008-02-06 01:38:35 -0800910 "or the key could not be retrieved. "
911 "Plaintext passthrough mode is not "
Michael Halcrowe10f2812007-06-27 14:09:44 -0700912 "enabled; returning -EIO\n");
Michael Halcrowe10f2812007-06-27 14:09:44 -0700913 mutex_unlock(&crypt_stat->cs_mutex);
Michael Halcrowe10f2812007-06-27 14:09:44 -0700914 goto out;
915 }
916 rc = 0;
917 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
918 mutex_unlock(&crypt_stat->cs_mutex);
Michael Halcrowe10f2812007-06-27 14:09:44 -0700919 goto out;
920 }
Michael Halcrowe10f2812007-06-27 14:09:44 -0700921 }
922 mutex_unlock(&crypt_stat->cs_mutex);
Michael Halcrow237fead2006-10-04 02:16:22 -0700923 if (ia->ia_valid & ATTR_SIZE) {
924 ecryptfs_printk(KERN_DEBUG,
925 "ia->ia_valid = [0x%x] ATTR_SIZE" " = [0x%x]\n",
926 ia->ia_valid, ATTR_SIZE);
927 rc = ecryptfs_truncate(dentry, ia->ia_size);
928 /* ecryptfs_truncate handles resizing of the lower file */
929 ia->ia_valid &= ~ATTR_SIZE;
930 ecryptfs_printk(KERN_DEBUG, "ia->ia_valid = [%x]\n",
931 ia->ia_valid);
932 if (rc < 0)
933 goto out;
934 }
Jeff Layton1ac564e2007-10-18 03:05:17 -0700935
936 /*
937 * mode change is for clearing setuid/setgid bits. Allow lower fs
938 * to interpret this in its own way.
939 */
940 if (ia->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
941 ia->ia_valid &= ~ATTR_MODE;
942
Miklos Szeredi9c3580a2008-04-29 00:59:48 -0700943 mutex_lock(&lower_dentry->d_inode->i_mutex);
Michael Halcrow237fead2006-10-04 02:16:22 -0700944 rc = notify_change(lower_dentry, ia);
Miklos Szeredi9c3580a2008-04-29 00:59:48 -0700945 mutex_unlock(&lower_dentry->d_inode->i_mutex);
Michael Halcrow237fead2006-10-04 02:16:22 -0700946out:
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -0800947 fsstack_copy_attr_all(inode, lower_inode, NULL);
Michael Halcrow237fead2006-10-04 02:16:22 -0700948 return rc;
949}
950
Michael Halcrowdd2a3b72007-02-12 00:53:46 -0800951int
Michael Halcrow237fead2006-10-04 02:16:22 -0700952ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value,
953 size_t size, int flags)
954{
955 int rc = 0;
956 struct dentry *lower_dentry;
957
958 lower_dentry = ecryptfs_dentry_to_lower(dentry);
959 if (!lower_dentry->d_inode->i_op->setxattr) {
960 rc = -ENOSYS;
961 goto out;
962 }
963 mutex_lock(&lower_dentry->d_inode->i_mutex);
964 rc = lower_dentry->d_inode->i_op->setxattr(lower_dentry, name, value,
965 size, flags);
966 mutex_unlock(&lower_dentry->d_inode->i_mutex);
967out:
968 return rc;
969}
970
Michael Halcrowdd2a3b72007-02-12 00:53:46 -0800971ssize_t
Michael Halcrowd7cdc5f2007-10-16 01:28:10 -0700972ecryptfs_getxattr_lower(struct dentry *lower_dentry, const char *name,
973 void *value, size_t size)
974{
975 int rc = 0;
976
977 if (!lower_dentry->d_inode->i_op->getxattr) {
978 rc = -ENOSYS;
979 goto out;
980 }
981 mutex_lock(&lower_dentry->d_inode->i_mutex);
982 rc = lower_dentry->d_inode->i_op->getxattr(lower_dentry, name, value,
983 size);
984 mutex_unlock(&lower_dentry->d_inode->i_mutex);
985out:
986 return rc;
987}
988
Adrian Bunk7896b632008-02-06 01:38:32 -0800989static ssize_t
Michael Halcrow237fead2006-10-04 02:16:22 -0700990ecryptfs_getxattr(struct dentry *dentry, const char *name, void *value,
991 size_t size)
992{
Michael Halcrow2ed92552007-10-16 01:28:10 -0700993 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry), name,
994 value, size);
Michael Halcrow237fead2006-10-04 02:16:22 -0700995}
996
997static ssize_t
998ecryptfs_listxattr(struct dentry *dentry, char *list, size_t size)
999{
1000 int rc = 0;
1001 struct dentry *lower_dentry;
1002
1003 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1004 if (!lower_dentry->d_inode->i_op->listxattr) {
1005 rc = -ENOSYS;
1006 goto out;
1007 }
1008 mutex_lock(&lower_dentry->d_inode->i_mutex);
1009 rc = lower_dentry->d_inode->i_op->listxattr(lower_dentry, list, size);
1010 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1011out:
1012 return rc;
1013}
1014
1015static int ecryptfs_removexattr(struct dentry *dentry, const char *name)
1016{
1017 int rc = 0;
1018 struct dentry *lower_dentry;
1019
1020 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1021 if (!lower_dentry->d_inode->i_op->removexattr) {
1022 rc = -ENOSYS;
1023 goto out;
1024 }
1025 mutex_lock(&lower_dentry->d_inode->i_mutex);
1026 rc = lower_dentry->d_inode->i_op->removexattr(lower_dentry, name);
1027 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1028out:
1029 return rc;
1030}
1031
1032int ecryptfs_inode_test(struct inode *inode, void *candidate_lower_inode)
1033{
1034 if ((ecryptfs_inode_to_lower(inode)
1035 == (struct inode *)candidate_lower_inode))
1036 return 1;
1037 else
1038 return 0;
1039}
1040
1041int ecryptfs_inode_set(struct inode *inode, void *lower_inode)
1042{
1043 ecryptfs_init_inode(inode, (struct inode *)lower_inode);
1044 return 0;
1045}
1046
Arjan van de Ven754661f2007-02-12 00:55:38 -08001047const struct inode_operations ecryptfs_symlink_iops = {
Michael Halcrow237fead2006-10-04 02:16:22 -07001048 .readlink = ecryptfs_readlink,
1049 .follow_link = ecryptfs_follow_link,
1050 .put_link = ecryptfs_put_link,
1051 .permission = ecryptfs_permission,
1052 .setattr = ecryptfs_setattr,
1053 .setxattr = ecryptfs_setxattr,
1054 .getxattr = ecryptfs_getxattr,
1055 .listxattr = ecryptfs_listxattr,
1056 .removexattr = ecryptfs_removexattr
1057};
1058
Arjan van de Ven754661f2007-02-12 00:55:38 -08001059const struct inode_operations ecryptfs_dir_iops = {
Michael Halcrow237fead2006-10-04 02:16:22 -07001060 .create = ecryptfs_create,
1061 .lookup = ecryptfs_lookup,
1062 .link = ecryptfs_link,
1063 .unlink = ecryptfs_unlink,
1064 .symlink = ecryptfs_symlink,
1065 .mkdir = ecryptfs_mkdir,
1066 .rmdir = ecryptfs_rmdir,
1067 .mknod = ecryptfs_mknod,
1068 .rename = ecryptfs_rename,
1069 .permission = ecryptfs_permission,
1070 .setattr = ecryptfs_setattr,
1071 .setxattr = ecryptfs_setxattr,
1072 .getxattr = ecryptfs_getxattr,
1073 .listxattr = ecryptfs_listxattr,
1074 .removexattr = ecryptfs_removexattr
1075};
1076
Arjan van de Ven754661f2007-02-12 00:55:38 -08001077const struct inode_operations ecryptfs_main_iops = {
Michael Halcrow237fead2006-10-04 02:16:22 -07001078 .permission = ecryptfs_permission,
1079 .setattr = ecryptfs_setattr,
1080 .setxattr = ecryptfs_setxattr,
1081 .getxattr = ecryptfs_getxattr,
1082 .listxattr = ecryptfs_listxattr,
1083 .removexattr = ecryptfs_removexattr
1084};