blob: 056fed62d0de8beb39f6a0ab6f195bb2577976e1 [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);
Tyler Hicksca8e34f2009-04-22 16:27:12 -0500382 mutex_lock(&lower_dir_dentry->d_inode->i_mutex);
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800383 lower_dentry = lookup_one_len(ecryptfs_dentry->d_name.name,
384 lower_dir_dentry,
385 ecryptfs_dentry->d_name.len);
Tyler Hicksca8e34f2009-04-22 16:27:12 -0500386 mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800387 if (IS_ERR(lower_dentry)) {
388 rc = PTR_ERR(lower_dentry);
389 printk(KERN_ERR "%s: lookup_one_len() returned [%d] on "
390 "lower_dentry = [%s]\n", __func__, rc,
391 ecryptfs_dentry->d_name.name);
392 goto out_d_drop;
393 }
394 if (lower_dentry->d_inode)
395 goto lookup_and_interpose;
Tyler Hicks2aac0cf2009-03-20 02:23:57 -0500396 mount_crypt_stat = &ecryptfs_superblock_to_private(
397 ecryptfs_dentry->d_sb)->mount_crypt_stat;
398 if (!(mount_crypt_stat
399 && (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)))
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800400 goto lookup_and_interpose;
401 dput(lower_dentry);
402 rc = ecryptfs_encrypt_and_encode_filename(
403 &encrypted_and_encoded_name, &encrypted_and_encoded_name_size,
Tyler Hicks2aac0cf2009-03-20 02:23:57 -0500404 NULL, mount_crypt_stat, ecryptfs_dentry->d_name.name,
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800405 ecryptfs_dentry->d_name.len);
406 if (rc) {
407 printk(KERN_ERR "%s: Error attempting to encrypt and encode "
408 "filename; rc = [%d]\n", __func__, rc);
409 goto out_d_drop;
410 }
Tyler Hicksca8e34f2009-04-22 16:27:12 -0500411 mutex_lock(&lower_dir_dentry->d_inode->i_mutex);
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800412 lower_dentry = lookup_one_len(encrypted_and_encoded_name,
413 lower_dir_dentry,
414 encrypted_and_encoded_name_size - 1);
Tyler Hicksca8e34f2009-04-22 16:27:12 -0500415 mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800416 if (IS_ERR(lower_dentry)) {
417 rc = PTR_ERR(lower_dentry);
418 printk(KERN_ERR "%s: lookup_one_len() returned [%d] on "
419 "lower_dentry = [%s]\n", __func__, rc,
420 encrypted_and_encoded_name);
421 goto out_d_drop;
422 }
423lookup_and_interpose:
424 rc = ecryptfs_lookup_and_interpose_lower(ecryptfs_dentry, lower_dentry,
Tyler Hicks2aac0cf2009-03-20 02:23:57 -0500425 ecryptfs_dir_inode,
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800426 ecryptfs_nd);
427 goto out;
428out_d_drop:
429 d_drop(ecryptfs_dentry);
430out:
431 kfree(encrypted_and_encoded_name);
Michael Halcrow237fead2006-10-04 02:16:22 -0700432 return ERR_PTR(rc);
433}
434
435static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
436 struct dentry *new_dentry)
437{
438 struct dentry *lower_old_dentry;
439 struct dentry *lower_new_dentry;
440 struct dentry *lower_dir_dentry;
441 u64 file_size_save;
442 int rc;
443
444 file_size_save = i_size_read(old_dentry->d_inode);
445 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
446 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
447 dget(lower_old_dentry);
448 dget(lower_new_dentry);
449 lower_dir_dentry = lock_parent(lower_new_dentry);
450 rc = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode,
451 lower_new_dentry);
452 if (rc || !lower_new_dentry->d_inode)
453 goto out_lock;
454 rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb, 0);
455 if (rc)
456 goto out_lock;
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -0800457 fsstack_copy_attr_times(dir, lower_new_dentry->d_inode);
458 fsstack_copy_inode_size(dir, lower_new_dentry->d_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700459 old_dentry->d_inode->i_nlink =
460 ecryptfs_inode_to_lower(old_dentry->d_inode)->i_nlink;
461 i_size_write(new_dentry->d_inode, file_size_save);
462out_lock:
463 unlock_dir(lower_dir_dentry);
464 dput(lower_new_dentry);
465 dput(lower_old_dentry);
Michael Halcrowae56fb12006-11-16 01:19:30 -0800466 d_drop(lower_old_dentry);
Michael Halcrow45ec4aba2006-10-30 22:07:20 -0800467 d_drop(new_dentry);
468 d_drop(old_dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -0700469 return rc;
470}
471
472static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
473{
474 int rc = 0;
475 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
476 struct inode *lower_dir_inode = ecryptfs_inode_to_lower(dir);
Miklos Szeredi8dc4e372008-05-12 14:02:04 -0700477 struct dentry *lower_dir_dentry;
Michael Halcrow237fead2006-10-04 02:16:22 -0700478
Tyler Hicks9c2d2052009-09-22 12:52:17 -0500479 dget(lower_dentry);
Miklos Szeredi8dc4e372008-05-12 14:02:04 -0700480 lower_dir_dentry = lock_parent(lower_dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -0700481 rc = vfs_unlink(lower_dir_inode, lower_dentry);
482 if (rc) {
Michael Halcrowae56fb12006-11-16 01:19:30 -0800483 printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc);
Michael Halcrow237fead2006-10-04 02:16:22 -0700484 goto out_unlock;
485 }
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -0800486 fsstack_copy_attr_times(dir, lower_dir_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700487 dentry->d_inode->i_nlink =
488 ecryptfs_inode_to_lower(dentry->d_inode)->i_nlink;
489 dentry->d_inode->i_ctime = dir->i_ctime;
Michael Halcrowcaeeeec2008-01-08 15:33:02 -0800490 d_drop(dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -0700491out_unlock:
Miklos Szeredi8dc4e372008-05-12 14:02:04 -0700492 unlock_dir(lower_dir_dentry);
Tyler Hicks9c2d2052009-09-22 12:52:17 -0500493 dput(lower_dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -0700494 return rc;
495}
496
497static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry,
498 const char *symname)
499{
500 int rc;
501 struct dentry *lower_dentry;
502 struct dentry *lower_dir_dentry;
Michael Halcrow237fead2006-10-04 02:16:22 -0700503 char *encoded_symname;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800504 size_t encoded_symlen;
505 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
Michael Halcrow237fead2006-10-04 02:16:22 -0700506
507 lower_dentry = ecryptfs_dentry_to_lower(dentry);
508 dget(lower_dentry);
509 lower_dir_dentry = lock_parent(lower_dentry);
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800510 mount_crypt_stat = &ecryptfs_superblock_to_private(
511 dir->i_sb)->mount_crypt_stat;
512 rc = ecryptfs_encrypt_and_encode_filename(&encoded_symname,
513 &encoded_symlen,
514 NULL,
515 mount_crypt_stat, symname,
516 strlen(symname));
517 if (rc)
Michael Halcrow237fead2006-10-04 02:16:22 -0700518 goto out_lock;
Michael Halcrow237fead2006-10-04 02:16:22 -0700519 rc = vfs_symlink(lower_dir_dentry->d_inode, lower_dentry,
Miklos Szeredidb2e7472008-06-24 16:50:16 +0200520 encoded_symname);
Michael Halcrow237fead2006-10-04 02:16:22 -0700521 kfree(encoded_symname);
522 if (rc || !lower_dentry->d_inode)
523 goto out_lock;
524 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
525 if (rc)
526 goto out_lock;
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -0800527 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
528 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700529out_lock:
530 unlock_dir(lower_dir_dentry);
531 dput(lower_dentry);
532 if (!dentry->d_inode)
533 d_drop(dentry);
534 return rc;
535}
536
537static int ecryptfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
538{
539 int rc;
540 struct dentry *lower_dentry;
541 struct dentry *lower_dir_dentry;
542
543 lower_dentry = ecryptfs_dentry_to_lower(dentry);
544 lower_dir_dentry = lock_parent(lower_dentry);
545 rc = vfs_mkdir(lower_dir_dentry->d_inode, lower_dentry, mode);
546 if (rc || !lower_dentry->d_inode)
547 goto out;
548 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
549 if (rc)
550 goto out;
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -0800551 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
552 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700553 dir->i_nlink = lower_dir_dentry->d_inode->i_nlink;
554out:
555 unlock_dir(lower_dir_dentry);
556 if (!dentry->d_inode)
557 d_drop(dentry);
558 return rc;
559}
560
561static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
562{
Michael Halcrow237fead2006-10-04 02:16:22 -0700563 struct dentry *lower_dentry;
Michael Halcrow237fead2006-10-04 02:16:22 -0700564 struct dentry *lower_dir_dentry;
Michael Halcrow45ec4aba2006-10-30 22:07:20 -0800565 int rc;
Michael Halcrow237fead2006-10-04 02:16:22 -0700566
567 lower_dentry = ecryptfs_dentry_to_lower(dentry);
Michael Halcrow45ec4aba2006-10-30 22:07:20 -0800568 dget(dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -0700569 lower_dir_dentry = lock_parent(lower_dentry);
Michael Halcrow45ec4aba2006-10-30 22:07:20 -0800570 dget(lower_dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -0700571 rc = vfs_rmdir(lower_dir_dentry->d_inode, lower_dentry);
Michael Halcrow45ec4aba2006-10-30 22:07:20 -0800572 dput(lower_dentry);
573 if (!rc)
574 d_delete(lower_dentry);
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -0800575 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700576 dir->i_nlink = lower_dir_dentry->d_inode->i_nlink;
577 unlock_dir(lower_dir_dentry);
578 if (!rc)
579 d_drop(dentry);
Michael Halcrow45ec4aba2006-10-30 22:07:20 -0800580 dput(dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -0700581 return rc;
582}
583
584static int
585ecryptfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
586{
587 int rc;
588 struct dentry *lower_dentry;
589 struct dentry *lower_dir_dentry;
590
591 lower_dentry = ecryptfs_dentry_to_lower(dentry);
592 lower_dir_dentry = lock_parent(lower_dentry);
593 rc = vfs_mknod(lower_dir_dentry->d_inode, lower_dentry, mode, dev);
594 if (rc || !lower_dentry->d_inode)
595 goto out;
Michael Halcrow391b52f2008-07-23 21:30:08 -0700596 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
Michael Halcrow237fead2006-10-04 02:16:22 -0700597 if (rc)
598 goto out;
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -0800599 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
600 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700601out:
602 unlock_dir(lower_dir_dentry);
603 if (!dentry->d_inode)
604 d_drop(dentry);
605 return rc;
606}
607
608static int
609ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
610 struct inode *new_dir, struct dentry *new_dentry)
611{
612 int rc;
613 struct dentry *lower_old_dentry;
614 struct dentry *lower_new_dentry;
615 struct dentry *lower_old_dir_dentry;
616 struct dentry *lower_new_dir_dentry;
617
618 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
619 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
620 dget(lower_old_dentry);
621 dget(lower_new_dentry);
622 lower_old_dir_dentry = dget_parent(lower_old_dentry);
623 lower_new_dir_dentry = dget_parent(lower_new_dentry);
624 lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
625 rc = vfs_rename(lower_old_dir_dentry->d_inode, lower_old_dentry,
626 lower_new_dir_dentry->d_inode, lower_new_dentry);
627 if (rc)
628 goto out_lock;
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -0800629 fsstack_copy_attr_all(new_dir, lower_new_dir_dentry->d_inode, NULL);
Michael Halcrow237fead2006-10-04 02:16:22 -0700630 if (new_dir != old_dir)
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -0800631 fsstack_copy_attr_all(old_dir, lower_old_dir_dentry->d_inode, NULL);
Michael Halcrow237fead2006-10-04 02:16:22 -0700632out_lock:
633 unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
Michael Halcrowa9083082006-11-16 01:19:16 -0800634 dput(lower_new_dentry->d_parent);
635 dput(lower_old_dentry->d_parent);
Michael Halcrow237fead2006-10-04 02:16:22 -0700636 dput(lower_new_dentry);
637 dput(lower_old_dentry);
638 return rc;
639}
640
641static int
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800642ecryptfs_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
Michael Halcrow237fead2006-10-04 02:16:22 -0700643{
Michael Halcrow237fead2006-10-04 02:16:22 -0700644 char *lower_buf;
Tyler Hicks3a6b42c2009-04-16 18:35:37 -0500645 size_t lower_bufsiz;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800646 struct dentry *lower_dentry;
Tyler Hicks3a6b42c2009-04-16 18:35:37 -0500647 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800648 char *plaintext_name;
649 size_t plaintext_name_size;
650 mm_segment_t old_fs;
651 int rc;
Michael Halcrow237fead2006-10-04 02:16:22 -0700652
653 lower_dentry = ecryptfs_dentry_to_lower(dentry);
Al Viroacfa4382008-12-04 10:06:33 -0500654 if (!lower_dentry->d_inode->i_op->readlink) {
Michael Halcrow237fead2006-10-04 02:16:22 -0700655 rc = -EINVAL;
656 goto out;
657 }
Tyler Hicks3a6b42c2009-04-16 18:35:37 -0500658 mount_crypt_stat = &ecryptfs_superblock_to_private(
659 dentry->d_sb)->mount_crypt_stat;
660 /*
661 * If the lower filename is encrypted, it will result in a significantly
662 * longer name. If needed, truncate the name after decode and decrypt.
663 */
664 if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
665 lower_bufsiz = PATH_MAX;
666 else
667 lower_bufsiz = bufsiz;
Michael Halcrow237fead2006-10-04 02:16:22 -0700668 /* Released in this function */
Tyler Hicks3a6b42c2009-04-16 18:35:37 -0500669 lower_buf = kmalloc(lower_bufsiz, GFP_KERNEL);
Michael Halcrow237fead2006-10-04 02:16:22 -0700670 if (lower_buf == NULL) {
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800671 printk(KERN_ERR "%s: Out of memory whilst attempting to "
Randy Dunlap802b3522009-04-27 21:24:28 -0700672 "kmalloc [%zd] bytes\n", __func__, lower_bufsiz);
Michael Halcrow237fead2006-10-04 02:16:22 -0700673 rc = -ENOMEM;
674 goto out;
675 }
676 old_fs = get_fs();
677 set_fs(get_ds());
Michael Halcrow237fead2006-10-04 02:16:22 -0700678 rc = lower_dentry->d_inode->i_op->readlink(lower_dentry,
679 (char __user *)lower_buf,
Tyler Hicks3a6b42c2009-04-16 18:35:37 -0500680 lower_bufsiz);
Michael Halcrow237fead2006-10-04 02:16:22 -0700681 set_fs(old_fs);
682 if (rc >= 0) {
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800683 rc = ecryptfs_decode_and_decrypt_filename(&plaintext_name,
684 &plaintext_name_size,
685 dentry, lower_buf,
686 rc);
687 if (rc) {
688 printk(KERN_ERR "%s: Error attempting to decode and "
689 "decrypt filename; rc = [%d]\n", __func__,
690 rc);
Michael Halcrow237fead2006-10-04 02:16:22 -0700691 goto out_free_lower_buf;
Michael Halcrow237fead2006-10-04 02:16:22 -0700692 }
Tyler Hicks3a6b42c2009-04-16 18:35:37 -0500693 /* Check for bufsiz <= 0 done in sys_readlinkat() */
694 rc = copy_to_user(buf, plaintext_name,
Tyler Hicksac201002009-04-27 13:31:12 -0500695 min((size_t) bufsiz, plaintext_name_size));
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800696 if (rc)
697 rc = -EFAULT;
698 else
699 rc = plaintext_name_size;
700 kfree(plaintext_name);
701 fsstack_copy_attr_atime(dentry->d_inode, lower_dentry->d_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700702 }
703out_free_lower_buf:
704 kfree(lower_buf);
705out:
706 return rc;
707}
708
709static void *ecryptfs_follow_link(struct dentry *dentry, struct nameidata *nd)
710{
711 char *buf;
712 int len = PAGE_SIZE, rc;
713 mm_segment_t old_fs;
714
715 /* Released in ecryptfs_put_link(); only release here on error */
716 buf = kmalloc(len, GFP_KERNEL);
717 if (!buf) {
718 rc = -ENOMEM;
719 goto out;
720 }
721 old_fs = get_fs();
722 set_fs(get_ds());
Michael Halcrow237fead2006-10-04 02:16:22 -0700723 rc = dentry->d_inode->i_op->readlink(dentry, (char __user *)buf, len);
Michael Halcrow237fead2006-10-04 02:16:22 -0700724 set_fs(old_fs);
725 if (rc < 0)
726 goto out_free;
Duane Griffina17d5232008-12-19 20:47:10 +0000727 else
728 buf[rc] = '\0';
Michael Halcrow237fead2006-10-04 02:16:22 -0700729 rc = 0;
730 nd_set_link(nd, buf);
731 goto out;
732out_free:
733 kfree(buf);
734out:
735 return ERR_PTR(rc);
736}
737
738static void
739ecryptfs_put_link(struct dentry *dentry, struct nameidata *nd, void *ptr)
740{
741 /* Free the char* */
742 kfree(nd_get_link(nd));
743}
744
745/**
746 * upper_size_to_lower_size
747 * @crypt_stat: Crypt_stat associated with file
748 * @upper_size: Size of the upper file
749 *
Michael Halcrowcc11bef2008-02-06 01:38:32 -0800750 * Calculate the required size of the lower file based on the
Michael Halcrow237fead2006-10-04 02:16:22 -0700751 * specified size of the upper file. This calculation is based on the
752 * number of headers in the underlying file and the extent size.
753 *
754 * Returns Calculated size of the lower file.
755 */
756static loff_t
757upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
758 loff_t upper_size)
759{
760 loff_t lower_size;
761
Michael Halcrowcc11bef2008-02-06 01:38:32 -0800762 lower_size = crypt_stat->num_header_bytes_at_front;
Michael Halcrow237fead2006-10-04 02:16:22 -0700763 if (upper_size != 0) {
764 loff_t num_extents;
765
766 num_extents = upper_size >> crypt_stat->extent_shift;
767 if (upper_size & ~crypt_stat->extent_mask)
768 num_extents++;
769 lower_size += (num_extents * crypt_stat->extent_size);
770 }
771 return lower_size;
772}
773
774/**
775 * ecryptfs_truncate
776 * @dentry: The ecryptfs layer dentry
777 * @new_length: The length to expand the file to
778 *
779 * Function to handle truncations modifying the size of the file. Note
780 * that the file sizes are interpolated. When expanding, we are simply
781 * writing strings of 0's out. When truncating, we need to modify the
782 * underlying file size according to the page index interpolations.
783 *
784 * Returns zero on success; non-zero otherwise
785 */
786int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
787{
788 int rc = 0;
789 struct inode *inode = dentry->d_inode;
790 struct dentry *lower_dentry;
Michael Halcrow2ed92552007-10-16 01:28:10 -0700791 struct file fake_ecryptfs_file;
Michael Halcrow237fead2006-10-04 02:16:22 -0700792 struct ecryptfs_crypt_stat *crypt_stat;
793 loff_t i_size = i_size_read(inode);
794 loff_t lower_size_before_truncate;
795 loff_t lower_size_after_truncate;
796
797 if (unlikely((new_length == i_size)))
798 goto out;
799 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
800 /* Set up a fake ecryptfs file, this is used to interface with
801 * the file in the underlying filesystem so that the
802 * truncation has an effect there as well. */
803 memset(&fake_ecryptfs_file, 0, sizeof(fake_ecryptfs_file));
Josef "Jeff" Sipekbd243a42006-12-08 02:36:48 -0800804 fake_ecryptfs_file.f_path.dentry = dentry;
Michael Halcrow237fead2006-10-04 02:16:22 -0700805 /* Released at out_free: label */
806 ecryptfs_set_file_private(&fake_ecryptfs_file,
807 kmem_cache_alloc(ecryptfs_file_info_cache,
Christoph Lametere94b1762006-12-06 20:33:17 -0800808 GFP_KERNEL));
Michael Halcrow237fead2006-10-04 02:16:22 -0700809 if (unlikely(!ecryptfs_file_to_private(&fake_ecryptfs_file))) {
810 rc = -ENOMEM;
811 goto out;
812 }
813 lower_dentry = ecryptfs_dentry_to_lower(dentry);
Michael Halcrow2ed92552007-10-16 01:28:10 -0700814 ecryptfs_set_file_lower(
815 &fake_ecryptfs_file,
816 ecryptfs_inode_to_private(dentry->d_inode)->lower_file);
Michael Halcrow237fead2006-10-04 02:16:22 -0700817 /* Switch on growing or shrinking file */
818 if (new_length > i_size) {
Michael Halcrow2ed92552007-10-16 01:28:10 -0700819 char zero[] = { 0x00 };
Michael Halcrow240e2df2007-06-27 14:09:44 -0700820
Michael Halcrow2ed92552007-10-16 01:28:10 -0700821 /* Write a single 0 at the last position of the file;
822 * this triggers code that will fill in 0's throughout
823 * the intermediate portion of the previous end of the
824 * file and the new and of the file */
825 rc = ecryptfs_write(&fake_ecryptfs_file, zero,
826 (new_length - 1), 1);
827 } else { /* new_length < i_size_read(inode) */
828 /* We're chopping off all the pages down do the page
829 * in which new_length is located. Fill in the end of
830 * that page from (new_length & ~PAGE_CACHE_MASK) to
831 * PAGE_CACHE_SIZE with zeros. */
832 size_t num_zeros = (PAGE_CACHE_SIZE
833 - (new_length & ~PAGE_CACHE_MASK));
834
Tyler Hicks13a791b2009-04-13 15:29:27 -0500835 if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
836 rc = vmtruncate(inode, new_length);
837 if (rc)
838 goto out_free;
839 rc = vmtruncate(lower_dentry->d_inode, new_length);
840 goto out_free;
841 }
Michael Halcrow2ed92552007-10-16 01:28:10 -0700842 if (num_zeros) {
843 char *zeros_virt;
844
845 zeros_virt = kzalloc(num_zeros, GFP_KERNEL);
846 if (!zeros_virt) {
847 rc = -ENOMEM;
848 goto out_free;
849 }
850 rc = ecryptfs_write(&fake_ecryptfs_file, zeros_virt,
851 new_length, num_zeros);
852 kfree(zeros_virt);
Michael Halcrow5dda6992007-10-16 01:28:06 -0700853 if (rc) {
Michael Halcrow240e2df2007-06-27 14:09:44 -0700854 printk(KERN_ERR "Error attempting to zero out "
855 "the remainder of the end page on "
856 "reducing truncate; rc = [%d]\n", rc);
Michael Halcrow2ed92552007-10-16 01:28:10 -0700857 goto out_free;
Michael Halcrow240e2df2007-06-27 14:09:44 -0700858 }
859 }
Michael Halcrow237fead2006-10-04 02:16:22 -0700860 vmtruncate(inode, new_length);
Michael Halcrow0216f7f2007-10-16 01:28:08 -0700861 rc = ecryptfs_write_inode_size_to_metadata(inode);
Michael Halcrowdd2a3b72007-02-12 00:53:46 -0800862 if (rc) {
863 printk(KERN_ERR "Problem with "
864 "ecryptfs_write_inode_size_to_metadata; "
865 "rc = [%d]\n", rc);
Michael Halcrow2ed92552007-10-16 01:28:10 -0700866 goto out_free;
Michael Halcrowdd2a3b72007-02-12 00:53:46 -0800867 }
Michael Halcrow237fead2006-10-04 02:16:22 -0700868 /* We are reducing the size of the ecryptfs file, and need to
869 * know if we need to reduce the size of the lower file. */
870 lower_size_before_truncate =
871 upper_size_to_lower_size(crypt_stat, i_size);
872 lower_size_after_truncate =
873 upper_size_to_lower_size(crypt_stat, new_length);
874 if (lower_size_after_truncate < lower_size_before_truncate)
875 vmtruncate(lower_dentry->d_inode,
876 lower_size_after_truncate);
877 }
Michael Halcrow237fead2006-10-04 02:16:22 -0700878out_free:
879 if (ecryptfs_file_to_private(&fake_ecryptfs_file))
880 kmem_cache_free(ecryptfs_file_info_cache,
881 ecryptfs_file_to_private(&fake_ecryptfs_file));
882out:
883 return rc;
884}
885
886static int
Al Viroe6305c42008-07-15 21:03:57 -0400887ecryptfs_permission(struct inode *inode, int mask)
Michael Halcrow237fead2006-10-04 02:16:22 -0700888{
Al Virof419a2e2008-07-22 00:07:17 -0400889 return inode_permission(ecryptfs_inode_to_lower(inode), mask);
Michael Halcrow237fead2006-10-04 02:16:22 -0700890}
891
892/**
893 * ecryptfs_setattr
894 * @dentry: dentry handle to the inode to modify
895 * @ia: Structure with flags of what to change and values
896 *
897 * Updates the metadata of an inode. If the update is to the size
898 * i.e. truncation, then ecryptfs_truncate will handle the size modification
899 * of both the ecryptfs inode and the lower inode.
900 *
901 * All other metadata changes will be passed right to the lower filesystem,
902 * and we will just update our inode to look like the lower.
903 */
904static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
905{
906 int rc = 0;
907 struct dentry *lower_dentry;
908 struct inode *inode;
909 struct inode *lower_inode;
910 struct ecryptfs_crypt_stat *crypt_stat;
911
912 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
Michael Halcrowe10f2812007-06-27 14:09:44 -0700913 if (!(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED))
914 ecryptfs_init_crypt_stat(crypt_stat);
Michael Halcrow237fead2006-10-04 02:16:22 -0700915 inode = dentry->d_inode;
916 lower_inode = ecryptfs_inode_to_lower(inode);
Michael Halcrowe10f2812007-06-27 14:09:44 -0700917 lower_dentry = ecryptfs_dentry_to_lower(dentry);
918 mutex_lock(&crypt_stat->cs_mutex);
919 if (S_ISDIR(dentry->d_inode->i_mode))
920 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
Michael Halcrow64ee4802007-07-19 01:47:54 -0700921 else if (S_ISREG(dentry->d_inode->i_mode)
922 && (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
923 || !(crypt_stat->flags & ECRYPTFS_KEY_VALID))) {
Michael Halcrowe10f2812007-06-27 14:09:44 -0700924 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
Michael Halcrowe10f2812007-06-27 14:09:44 -0700925
Michael Halcrowe10f2812007-06-27 14:09:44 -0700926 mount_crypt_stat = &ecryptfs_superblock_to_private(
927 dentry->d_sb)->mount_crypt_stat;
Michael Halcrowd7cdc5f2007-10-16 01:28:10 -0700928 rc = ecryptfs_read_metadata(dentry);
Michael Halcrow5dda6992007-10-16 01:28:06 -0700929 if (rc) {
Michael Halcrowe10f2812007-06-27 14:09:44 -0700930 if (!(mount_crypt_stat->flags
931 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
932 rc = -EIO;
Michael Halcrow25bd8172008-02-06 01:38:35 -0800933 printk(KERN_WARNING "Either the lower file "
Michael Halcrowe10f2812007-06-27 14:09:44 -0700934 "is not in a valid eCryptfs format, "
Michael Halcrow25bd8172008-02-06 01:38:35 -0800935 "or the key could not be retrieved. "
936 "Plaintext passthrough mode is not "
Michael Halcrowe10f2812007-06-27 14:09:44 -0700937 "enabled; returning -EIO\n");
Michael Halcrowe10f2812007-06-27 14:09:44 -0700938 mutex_unlock(&crypt_stat->cs_mutex);
Michael Halcrowe10f2812007-06-27 14:09:44 -0700939 goto out;
940 }
941 rc = 0;
942 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
Michael Halcrowe10f2812007-06-27 14:09:44 -0700943 }
Michael Halcrowe10f2812007-06-27 14:09:44 -0700944 }
945 mutex_unlock(&crypt_stat->cs_mutex);
Michael Halcrow237fead2006-10-04 02:16:22 -0700946 if (ia->ia_valid & ATTR_SIZE) {
947 ecryptfs_printk(KERN_DEBUG,
948 "ia->ia_valid = [0x%x] ATTR_SIZE" " = [0x%x]\n",
949 ia->ia_valid, ATTR_SIZE);
950 rc = ecryptfs_truncate(dentry, ia->ia_size);
951 /* ecryptfs_truncate handles resizing of the lower file */
952 ia->ia_valid &= ~ATTR_SIZE;
953 ecryptfs_printk(KERN_DEBUG, "ia->ia_valid = [%x]\n",
954 ia->ia_valid);
955 if (rc < 0)
956 goto out;
957 }
Jeff Layton1ac564e2007-10-18 03:05:17 -0700958
959 /*
960 * mode change is for clearing setuid/setgid bits. Allow lower fs
961 * to interpret this in its own way.
962 */
963 if (ia->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
964 ia->ia_valid &= ~ATTR_MODE;
965
Miklos Szeredi9c3580a2008-04-29 00:59:48 -0700966 mutex_lock(&lower_dentry->d_inode->i_mutex);
Michael Halcrow237fead2006-10-04 02:16:22 -0700967 rc = notify_change(lower_dentry, ia);
Miklos Szeredi9c3580a2008-04-29 00:59:48 -0700968 mutex_unlock(&lower_dentry->d_inode->i_mutex);
Michael Halcrow237fead2006-10-04 02:16:22 -0700969out:
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -0800970 fsstack_copy_attr_all(inode, lower_inode, NULL);
Michael Halcrow237fead2006-10-04 02:16:22 -0700971 return rc;
972}
973
Michael Halcrowdd2a3b72007-02-12 00:53:46 -0800974int
Michael Halcrow237fead2006-10-04 02:16:22 -0700975ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value,
976 size_t size, int flags)
977{
978 int rc = 0;
979 struct dentry *lower_dentry;
980
981 lower_dentry = ecryptfs_dentry_to_lower(dentry);
982 if (!lower_dentry->d_inode->i_op->setxattr) {
983 rc = -ENOSYS;
984 goto out;
985 }
986 mutex_lock(&lower_dentry->d_inode->i_mutex);
987 rc = lower_dentry->d_inode->i_op->setxattr(lower_dentry, name, value,
988 size, flags);
989 mutex_unlock(&lower_dentry->d_inode->i_mutex);
990out:
991 return rc;
992}
993
Michael Halcrowdd2a3b72007-02-12 00:53:46 -0800994ssize_t
Michael Halcrowd7cdc5f2007-10-16 01:28:10 -0700995ecryptfs_getxattr_lower(struct dentry *lower_dentry, const char *name,
996 void *value, size_t size)
997{
998 int rc = 0;
999
1000 if (!lower_dentry->d_inode->i_op->getxattr) {
1001 rc = -ENOSYS;
1002 goto out;
1003 }
1004 mutex_lock(&lower_dentry->d_inode->i_mutex);
1005 rc = lower_dentry->d_inode->i_op->getxattr(lower_dentry, name, value,
1006 size);
1007 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1008out:
1009 return rc;
1010}
1011
Adrian Bunk7896b632008-02-06 01:38:32 -08001012static ssize_t
Michael Halcrow237fead2006-10-04 02:16:22 -07001013ecryptfs_getxattr(struct dentry *dentry, const char *name, void *value,
1014 size_t size)
1015{
Michael Halcrow2ed92552007-10-16 01:28:10 -07001016 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry), name,
1017 value, size);
Michael Halcrow237fead2006-10-04 02:16:22 -07001018}
1019
1020static ssize_t
1021ecryptfs_listxattr(struct dentry *dentry, char *list, size_t size)
1022{
1023 int rc = 0;
1024 struct dentry *lower_dentry;
1025
1026 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1027 if (!lower_dentry->d_inode->i_op->listxattr) {
1028 rc = -ENOSYS;
1029 goto out;
1030 }
1031 mutex_lock(&lower_dentry->d_inode->i_mutex);
1032 rc = lower_dentry->d_inode->i_op->listxattr(lower_dentry, list, size);
1033 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1034out:
1035 return rc;
1036}
1037
1038static int ecryptfs_removexattr(struct dentry *dentry, const char *name)
1039{
1040 int rc = 0;
1041 struct dentry *lower_dentry;
1042
1043 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1044 if (!lower_dentry->d_inode->i_op->removexattr) {
1045 rc = -ENOSYS;
1046 goto out;
1047 }
1048 mutex_lock(&lower_dentry->d_inode->i_mutex);
1049 rc = lower_dentry->d_inode->i_op->removexattr(lower_dentry, name);
1050 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1051out:
1052 return rc;
1053}
1054
1055int ecryptfs_inode_test(struct inode *inode, void *candidate_lower_inode)
1056{
1057 if ((ecryptfs_inode_to_lower(inode)
1058 == (struct inode *)candidate_lower_inode))
1059 return 1;
1060 else
1061 return 0;
1062}
1063
1064int ecryptfs_inode_set(struct inode *inode, void *lower_inode)
1065{
1066 ecryptfs_init_inode(inode, (struct inode *)lower_inode);
1067 return 0;
1068}
1069
Arjan van de Ven754661f2007-02-12 00:55:38 -08001070const struct inode_operations ecryptfs_symlink_iops = {
Michael Halcrow237fead2006-10-04 02:16:22 -07001071 .readlink = ecryptfs_readlink,
1072 .follow_link = ecryptfs_follow_link,
1073 .put_link = ecryptfs_put_link,
1074 .permission = ecryptfs_permission,
1075 .setattr = ecryptfs_setattr,
1076 .setxattr = ecryptfs_setxattr,
1077 .getxattr = ecryptfs_getxattr,
1078 .listxattr = ecryptfs_listxattr,
1079 .removexattr = ecryptfs_removexattr
1080};
1081
Arjan van de Ven754661f2007-02-12 00:55:38 -08001082const struct inode_operations ecryptfs_dir_iops = {
Michael Halcrow237fead2006-10-04 02:16:22 -07001083 .create = ecryptfs_create,
1084 .lookup = ecryptfs_lookup,
1085 .link = ecryptfs_link,
1086 .unlink = ecryptfs_unlink,
1087 .symlink = ecryptfs_symlink,
1088 .mkdir = ecryptfs_mkdir,
1089 .rmdir = ecryptfs_rmdir,
1090 .mknod = ecryptfs_mknod,
1091 .rename = ecryptfs_rename,
1092 .permission = ecryptfs_permission,
1093 .setattr = ecryptfs_setattr,
1094 .setxattr = ecryptfs_setxattr,
1095 .getxattr = ecryptfs_getxattr,
1096 .listxattr = ecryptfs_listxattr,
1097 .removexattr = ecryptfs_removexattr
1098};
1099
Arjan van de Ven754661f2007-02-12 00:55:38 -08001100const struct inode_operations ecryptfs_main_iops = {
Michael Halcrow237fead2006-10-04 02:16:22 -07001101 .permission = ecryptfs_permission,
1102 .setattr = ecryptfs_setattr,
1103 .setxattr = ecryptfs_setxattr,
1104 .getxattr = ecryptfs_getxattr,
1105 .listxattr = ecryptfs_listxattr,
1106 .removexattr = ecryptfs_removexattr
1107};