blob: 4a430ab4115c056851a9a98788417a44751e6205 [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,
Erez Zadok3469b572009-12-06 18:51:15 -0500285 ecryptfs_dir_inode->i_sb,
286 ECRYPTFS_INTERPOSE_FLAG_D_ADD);
Michael Halcrow237fead2006-10-04 02:16:22 -0700287 if (rc) {
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800288 printk(KERN_ERR "%s: Error interposing; rc = [%d]\n",
289 __func__, rc);
Michael Halcrow391b52f2008-07-23 21:30:08 -0700290 goto out;
Michael Halcrow237fead2006-10-04 02:16:22 -0700291 }
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800292 if (S_ISDIR(lower_inode->i_mode))
Michael Halcrow237fead2006-10-04 02:16:22 -0700293 goto out;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800294 if (S_ISLNK(lower_inode->i_mode))
Michael Halcrow237fead2006-10-04 02:16:22 -0700295 goto out;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800296 if (special_file(lower_inode->i_mode))
Ryusuke Konishi202a21d2007-08-10 13:00:51 -0700297 goto out;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800298 if (!ecryptfs_nd)
Michael Halcrow237fead2006-10-04 02:16:22 -0700299 goto out;
Michael Halcrow237fead2006-10-04 02:16:22 -0700300 /* Released in this function */
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800301 page_virt = kmem_cache_zalloc(ecryptfs_header_cache_2, GFP_USER);
Michael Halcrow237fead2006-10-04 02:16:22 -0700302 if (!page_virt) {
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800303 printk(KERN_ERR "%s: Cannot kmem_cache_zalloc() a page\n",
304 __func__);
Michael Halcrow237fead2006-10-04 02:16:22 -0700305 rc = -ENOMEM;
Michael Halcrow391b52f2008-07-23 21:30:08 -0700306 goto out;
Michael Halcrow237fead2006-10-04 02:16:22 -0700307 }
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800308 if (!ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->lower_file) {
309 rc = ecryptfs_init_persistent_file(ecryptfs_dentry);
Michael Halcrow391b52f2008-07-23 21:30:08 -0700310 if (rc) {
311 printk(KERN_ERR "%s: Error attempting to initialize "
312 "the persistent file for the dentry with name "
313 "[%s]; rc = [%d]\n", __func__,
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800314 ecryptfs_dentry->d_name.name, rc);
315 goto out_free_kmem;
Michael Halcrow391b52f2008-07-23 21:30:08 -0700316 }
317 }
Tyler Hicks2aac0cf2009-03-20 02:23:57 -0500318 crypt_stat = &ecryptfs_inode_to_private(
319 ecryptfs_dentry->d_inode)->crypt_stat;
320 /* TODO: lock for crypt_stat comparison */
321 if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED))
322 ecryptfs_set_default_sizes(crypt_stat);
Michael Halcrowd7cdc5f2007-10-16 01:28:10 -0700323 rc = ecryptfs_read_and_validate_header_region(page_virt,
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800324 ecryptfs_dentry->d_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700325 if (rc) {
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800326 rc = ecryptfs_read_and_validate_xattr_region(page_virt,
327 ecryptfs_dentry);
Michael Halcrowdd2a3b72007-02-12 00:53:46 -0800328 if (rc) {
Michael Halcrowdd2a3b72007-02-12 00:53:46 -0800329 rc = 0;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800330 goto out_free_kmem;
Michael Halcrow237fead2006-10-04 02:16:22 -0700331 }
Michael Halcrowdd2a3b72007-02-12 00:53:46 -0800332 crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
Michael Halcrow237fead2006-10-04 02:16:22 -0700333 }
Michael Halcrowe77a56d2007-02-12 00:53:47 -0800334 mount_crypt_stat = &ecryptfs_superblock_to_private(
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800335 ecryptfs_dentry->d_sb)->mount_crypt_stat;
Michael Halcrowe77a56d2007-02-12 00:53:47 -0800336 if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) {
337 if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
Michael Halcrowcc11bef2008-02-06 01:38:32 -0800338 file_size = (crypt_stat->num_header_bytes_at_front
Michael Halcrowe77a56d2007-02-12 00:53:47 -0800339 + i_size_read(lower_dentry->d_inode));
340 else
341 file_size = i_size_read(lower_dentry->d_inode);
342 } else {
Harvey Harrison0a688ad2008-07-23 21:30:07 -0700343 file_size = get_unaligned_be64(page_virt);
Michael Halcrowe77a56d2007-02-12 00:53:47 -0800344 }
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800345 i_size_write(ecryptfs_dentry->d_inode, (loff_t)file_size);
346out_free_kmem:
Michael Halcrow237fead2006-10-04 02:16:22 -0700347 kmem_cache_free(ecryptfs_header_cache_2, page_virt);
348 goto out;
Michael Halcrow237fead2006-10-04 02:16:22 -0700349out_dput:
350 dput(lower_dentry);
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800351 d_drop(ecryptfs_dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -0700352out:
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800353 return rc;
354}
355
356/**
357 * ecryptfs_lookup
358 * @ecryptfs_dir_inode: The eCryptfs directory inode
359 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
360 * @ecryptfs_nd: nameidata; may be NULL
361 *
362 * Find a file on disk. If the file does not exist, then we'll add it to the
363 * dentry cache and continue on to read it from the disk.
364 */
365static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
366 struct dentry *ecryptfs_dentry,
367 struct nameidata *ecryptfs_nd)
368{
369 char *encrypted_and_encoded_name = NULL;
Michael Halcrowa8f12862009-01-06 14:42:03 -0800370 size_t encrypted_and_encoded_name_size;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800371 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800372 struct dentry *lower_dir_dentry, *lower_dentry;
373 int rc = 0;
374
375 ecryptfs_dentry->d_op = &ecryptfs_dops;
376 if ((ecryptfs_dentry->d_name.len == 1
377 && !strcmp(ecryptfs_dentry->d_name.name, "."))
378 || (ecryptfs_dentry->d_name.len == 2
379 && !strcmp(ecryptfs_dentry->d_name.name, ".."))) {
380 goto out_d_drop;
381 }
382 lower_dir_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry->d_parent);
Tyler Hicksca8e34f2009-04-22 16:27:12 -0500383 mutex_lock(&lower_dir_dentry->d_inode->i_mutex);
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800384 lower_dentry = lookup_one_len(ecryptfs_dentry->d_name.name,
385 lower_dir_dentry,
386 ecryptfs_dentry->d_name.len);
Tyler Hicksca8e34f2009-04-22 16:27:12 -0500387 mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800388 if (IS_ERR(lower_dentry)) {
389 rc = PTR_ERR(lower_dentry);
390 printk(KERN_ERR "%s: lookup_one_len() returned [%d] on "
391 "lower_dentry = [%s]\n", __func__, rc,
392 ecryptfs_dentry->d_name.name);
393 goto out_d_drop;
394 }
395 if (lower_dentry->d_inode)
396 goto lookup_and_interpose;
Tyler Hicks2aac0cf2009-03-20 02:23:57 -0500397 mount_crypt_stat = &ecryptfs_superblock_to_private(
398 ecryptfs_dentry->d_sb)->mount_crypt_stat;
399 if (!(mount_crypt_stat
400 && (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)))
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800401 goto lookup_and_interpose;
402 dput(lower_dentry);
403 rc = ecryptfs_encrypt_and_encode_filename(
404 &encrypted_and_encoded_name, &encrypted_and_encoded_name_size,
Tyler Hicks2aac0cf2009-03-20 02:23:57 -0500405 NULL, mount_crypt_stat, ecryptfs_dentry->d_name.name,
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800406 ecryptfs_dentry->d_name.len);
407 if (rc) {
408 printk(KERN_ERR "%s: Error attempting to encrypt and encode "
409 "filename; rc = [%d]\n", __func__, rc);
410 goto out_d_drop;
411 }
Tyler Hicksca8e34f2009-04-22 16:27:12 -0500412 mutex_lock(&lower_dir_dentry->d_inode->i_mutex);
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800413 lower_dentry = lookup_one_len(encrypted_and_encoded_name,
414 lower_dir_dentry,
415 encrypted_and_encoded_name_size - 1);
Tyler Hicksca8e34f2009-04-22 16:27:12 -0500416 mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800417 if (IS_ERR(lower_dentry)) {
418 rc = PTR_ERR(lower_dentry);
419 printk(KERN_ERR "%s: lookup_one_len() returned [%d] on "
420 "lower_dentry = [%s]\n", __func__, rc,
421 encrypted_and_encoded_name);
422 goto out_d_drop;
423 }
424lookup_and_interpose:
425 rc = ecryptfs_lookup_and_interpose_lower(ecryptfs_dentry, lower_dentry,
Tyler Hicks2aac0cf2009-03-20 02:23:57 -0500426 ecryptfs_dir_inode,
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800427 ecryptfs_nd);
428 goto out;
429out_d_drop:
430 d_drop(ecryptfs_dentry);
431out:
432 kfree(encrypted_and_encoded_name);
Michael Halcrow237fead2006-10-04 02:16:22 -0700433 return ERR_PTR(rc);
434}
435
436static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
437 struct dentry *new_dentry)
438{
439 struct dentry *lower_old_dentry;
440 struct dentry *lower_new_dentry;
441 struct dentry *lower_dir_dentry;
442 u64 file_size_save;
443 int rc;
444
445 file_size_save = i_size_read(old_dentry->d_inode);
446 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
447 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
448 dget(lower_old_dentry);
449 dget(lower_new_dentry);
450 lower_dir_dentry = lock_parent(lower_new_dentry);
451 rc = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode,
452 lower_new_dentry);
453 if (rc || !lower_new_dentry->d_inode)
454 goto out_lock;
455 rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb, 0);
456 if (rc)
457 goto out_lock;
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -0800458 fsstack_copy_attr_times(dir, lower_new_dentry->d_inode);
459 fsstack_copy_inode_size(dir, lower_new_dentry->d_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700460 old_dentry->d_inode->i_nlink =
461 ecryptfs_inode_to_lower(old_dentry->d_inode)->i_nlink;
462 i_size_write(new_dentry->d_inode, file_size_save);
463out_lock:
464 unlock_dir(lower_dir_dentry);
465 dput(lower_new_dentry);
466 dput(lower_old_dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -0700467 return rc;
468}
469
470static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
471{
472 int rc = 0;
473 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
474 struct inode *lower_dir_inode = ecryptfs_inode_to_lower(dir);
Miklos Szeredi8dc4e372008-05-12 14:02:04 -0700475 struct dentry *lower_dir_dentry;
Michael Halcrow237fead2006-10-04 02:16:22 -0700476
Tyler Hicks9c2d2052009-09-22 12:52:17 -0500477 dget(lower_dentry);
Miklos Szeredi8dc4e372008-05-12 14:02:04 -0700478 lower_dir_dentry = lock_parent(lower_dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -0700479 rc = vfs_unlink(lower_dir_inode, lower_dentry);
480 if (rc) {
Michael Halcrowae56fb12006-11-16 01:19:30 -0800481 printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc);
Michael Halcrow237fead2006-10-04 02:16:22 -0700482 goto out_unlock;
483 }
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -0800484 fsstack_copy_attr_times(dir, lower_dir_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700485 dentry->d_inode->i_nlink =
486 ecryptfs_inode_to_lower(dentry->d_inode)->i_nlink;
487 dentry->d_inode->i_ctime = dir->i_ctime;
Michael Halcrowcaeeeec2008-01-08 15:33:02 -0800488 d_drop(dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -0700489out_unlock:
Miklos Szeredi8dc4e372008-05-12 14:02:04 -0700490 unlock_dir(lower_dir_dentry);
Tyler Hicks9c2d2052009-09-22 12:52:17 -0500491 dput(lower_dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -0700492 return rc;
493}
494
495static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry,
496 const char *symname)
497{
498 int rc;
499 struct dentry *lower_dentry;
500 struct dentry *lower_dir_dentry;
Michael Halcrow237fead2006-10-04 02:16:22 -0700501 char *encoded_symname;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800502 size_t encoded_symlen;
503 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
Michael Halcrow237fead2006-10-04 02:16:22 -0700504
505 lower_dentry = ecryptfs_dentry_to_lower(dentry);
506 dget(lower_dentry);
507 lower_dir_dentry = lock_parent(lower_dentry);
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800508 mount_crypt_stat = &ecryptfs_superblock_to_private(
509 dir->i_sb)->mount_crypt_stat;
510 rc = ecryptfs_encrypt_and_encode_filename(&encoded_symname,
511 &encoded_symlen,
512 NULL,
513 mount_crypt_stat, symname,
514 strlen(symname));
515 if (rc)
Michael Halcrow237fead2006-10-04 02:16:22 -0700516 goto out_lock;
Michael Halcrow237fead2006-10-04 02:16:22 -0700517 rc = vfs_symlink(lower_dir_dentry->d_inode, lower_dentry,
Miklos Szeredidb2e7472008-06-24 16:50:16 +0200518 encoded_symname);
Michael Halcrow237fead2006-10-04 02:16:22 -0700519 kfree(encoded_symname);
520 if (rc || !lower_dentry->d_inode)
521 goto out_lock;
522 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
523 if (rc)
524 goto out_lock;
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -0800525 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
526 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700527out_lock:
528 unlock_dir(lower_dir_dentry);
529 dput(lower_dentry);
530 if (!dentry->d_inode)
531 d_drop(dentry);
532 return rc;
533}
534
535static int ecryptfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
536{
537 int rc;
538 struct dentry *lower_dentry;
539 struct dentry *lower_dir_dentry;
540
541 lower_dentry = ecryptfs_dentry_to_lower(dentry);
542 lower_dir_dentry = lock_parent(lower_dentry);
543 rc = vfs_mkdir(lower_dir_dentry->d_inode, lower_dentry, mode);
544 if (rc || !lower_dentry->d_inode)
545 goto out;
546 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
547 if (rc)
548 goto out;
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -0800549 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
550 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700551 dir->i_nlink = lower_dir_dentry->d_inode->i_nlink;
552out:
553 unlock_dir(lower_dir_dentry);
554 if (!dentry->d_inode)
555 d_drop(dentry);
556 return rc;
557}
558
559static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
560{
Michael Halcrow237fead2006-10-04 02:16:22 -0700561 struct dentry *lower_dentry;
Michael Halcrow237fead2006-10-04 02:16:22 -0700562 struct dentry *lower_dir_dentry;
Michael Halcrow45ec4aba2006-10-30 22:07:20 -0800563 int rc;
Michael Halcrow237fead2006-10-04 02:16:22 -0700564
565 lower_dentry = ecryptfs_dentry_to_lower(dentry);
Michael Halcrow45ec4aba2006-10-30 22:07:20 -0800566 dget(dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -0700567 lower_dir_dentry = lock_parent(lower_dentry);
Michael Halcrow45ec4aba2006-10-30 22:07:20 -0800568 dget(lower_dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -0700569 rc = vfs_rmdir(lower_dir_dentry->d_inode, lower_dentry);
Michael Halcrow45ec4aba2006-10-30 22:07:20 -0800570 dput(lower_dentry);
571 if (!rc)
572 d_delete(lower_dentry);
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -0800573 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700574 dir->i_nlink = lower_dir_dentry->d_inode->i_nlink;
575 unlock_dir(lower_dir_dentry);
576 if (!rc)
577 d_drop(dentry);
Michael Halcrow45ec4aba2006-10-30 22:07:20 -0800578 dput(dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -0700579 return rc;
580}
581
582static int
583ecryptfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
584{
585 int rc;
586 struct dentry *lower_dentry;
587 struct dentry *lower_dir_dentry;
588
589 lower_dentry = ecryptfs_dentry_to_lower(dentry);
590 lower_dir_dentry = lock_parent(lower_dentry);
591 rc = vfs_mknod(lower_dir_dentry->d_inode, lower_dentry, mode, dev);
592 if (rc || !lower_dentry->d_inode)
593 goto out;
Michael Halcrow391b52f2008-07-23 21:30:08 -0700594 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
Michael Halcrow237fead2006-10-04 02:16:22 -0700595 if (rc)
596 goto out;
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -0800597 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
598 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700599out:
600 unlock_dir(lower_dir_dentry);
601 if (!dentry->d_inode)
602 d_drop(dentry);
603 return rc;
604}
605
606static int
607ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
608 struct inode *new_dir, struct dentry *new_dentry)
609{
610 int rc;
611 struct dentry *lower_old_dentry;
612 struct dentry *lower_new_dentry;
613 struct dentry *lower_old_dir_dentry;
614 struct dentry *lower_new_dir_dentry;
Erez Zadok0d132f72009-12-05 21:17:09 -0500615 struct dentry *trap = NULL;
Michael Halcrow237fead2006-10-04 02:16:22 -0700616
617 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
618 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
619 dget(lower_old_dentry);
620 dget(lower_new_dentry);
621 lower_old_dir_dentry = dget_parent(lower_old_dentry);
622 lower_new_dir_dentry = dget_parent(lower_new_dentry);
Erez Zadok0d132f72009-12-05 21:17:09 -0500623 trap = lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
624 /* source should not be ancestor of target */
625 if (trap == lower_old_dentry) {
626 rc = -EINVAL;
627 goto out_lock;
628 }
629 /* target should not be ancestor of source */
630 if (trap == lower_new_dentry) {
631 rc = -ENOTEMPTY;
632 goto out_lock;
633 }
Michael Halcrow237fead2006-10-04 02:16:22 -0700634 rc = vfs_rename(lower_old_dir_dentry->d_inode, lower_old_dentry,
635 lower_new_dir_dentry->d_inode, lower_new_dentry);
636 if (rc)
637 goto out_lock;
Erez Zadok9afa2fb2009-12-02 19:51:54 -0500638 fsstack_copy_attr_all(new_dir, lower_new_dir_dentry->d_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700639 if (new_dir != old_dir)
Erez Zadok9afa2fb2009-12-02 19:51:54 -0500640 fsstack_copy_attr_all(old_dir, lower_old_dir_dentry->d_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700641out_lock:
642 unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
Michael Halcrowa9083082006-11-16 01:19:16 -0800643 dput(lower_new_dentry->d_parent);
644 dput(lower_old_dentry->d_parent);
Michael Halcrow237fead2006-10-04 02:16:22 -0700645 dput(lower_new_dentry);
646 dput(lower_old_dentry);
647 return rc;
648}
649
650static int
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800651ecryptfs_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
Michael Halcrow237fead2006-10-04 02:16:22 -0700652{
Michael Halcrow237fead2006-10-04 02:16:22 -0700653 char *lower_buf;
Tyler Hicks3a6b42c2009-04-16 18:35:37 -0500654 size_t lower_bufsiz;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800655 struct dentry *lower_dentry;
Tyler Hicks3a6b42c2009-04-16 18:35:37 -0500656 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800657 char *plaintext_name;
658 size_t plaintext_name_size;
659 mm_segment_t old_fs;
660 int rc;
Michael Halcrow237fead2006-10-04 02:16:22 -0700661
662 lower_dentry = ecryptfs_dentry_to_lower(dentry);
Al Viroacfa4382008-12-04 10:06:33 -0500663 if (!lower_dentry->d_inode->i_op->readlink) {
Michael Halcrow237fead2006-10-04 02:16:22 -0700664 rc = -EINVAL;
665 goto out;
666 }
Tyler Hicks3a6b42c2009-04-16 18:35:37 -0500667 mount_crypt_stat = &ecryptfs_superblock_to_private(
668 dentry->d_sb)->mount_crypt_stat;
669 /*
670 * If the lower filename is encrypted, it will result in a significantly
671 * longer name. If needed, truncate the name after decode and decrypt.
672 */
673 if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
674 lower_bufsiz = PATH_MAX;
675 else
676 lower_bufsiz = bufsiz;
Michael Halcrow237fead2006-10-04 02:16:22 -0700677 /* Released in this function */
Tyler Hicks3a6b42c2009-04-16 18:35:37 -0500678 lower_buf = kmalloc(lower_bufsiz, GFP_KERNEL);
Michael Halcrow237fead2006-10-04 02:16:22 -0700679 if (lower_buf == NULL) {
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800680 printk(KERN_ERR "%s: Out of memory whilst attempting to "
Randy Dunlap802b3522009-04-27 21:24:28 -0700681 "kmalloc [%zd] bytes\n", __func__, lower_bufsiz);
Michael Halcrow237fead2006-10-04 02:16:22 -0700682 rc = -ENOMEM;
683 goto out;
684 }
685 old_fs = get_fs();
686 set_fs(get_ds());
Michael Halcrow237fead2006-10-04 02:16:22 -0700687 rc = lower_dentry->d_inode->i_op->readlink(lower_dentry,
688 (char __user *)lower_buf,
Tyler Hicks3a6b42c2009-04-16 18:35:37 -0500689 lower_bufsiz);
Michael Halcrow237fead2006-10-04 02:16:22 -0700690 set_fs(old_fs);
691 if (rc >= 0) {
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800692 rc = ecryptfs_decode_and_decrypt_filename(&plaintext_name,
693 &plaintext_name_size,
694 dentry, lower_buf,
695 rc);
696 if (rc) {
697 printk(KERN_ERR "%s: Error attempting to decode and "
698 "decrypt filename; rc = [%d]\n", __func__,
699 rc);
Michael Halcrow237fead2006-10-04 02:16:22 -0700700 goto out_free_lower_buf;
Michael Halcrow237fead2006-10-04 02:16:22 -0700701 }
Tyler Hicks3a6b42c2009-04-16 18:35:37 -0500702 /* Check for bufsiz <= 0 done in sys_readlinkat() */
703 rc = copy_to_user(buf, plaintext_name,
Tyler Hicksac201002009-04-27 13:31:12 -0500704 min((size_t) bufsiz, plaintext_name_size));
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800705 if (rc)
706 rc = -EFAULT;
707 else
708 rc = plaintext_name_size;
709 kfree(plaintext_name);
710 fsstack_copy_attr_atime(dentry->d_inode, lower_dentry->d_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700711 }
712out_free_lower_buf:
713 kfree(lower_buf);
714out:
715 return rc;
716}
717
718static void *ecryptfs_follow_link(struct dentry *dentry, struct nameidata *nd)
719{
720 char *buf;
721 int len = PAGE_SIZE, rc;
722 mm_segment_t old_fs;
723
724 /* Released in ecryptfs_put_link(); only release here on error */
725 buf = kmalloc(len, GFP_KERNEL);
726 if (!buf) {
OGAWA Hirofumi806892e2010-01-12 03:36:14 +0900727 buf = ERR_PTR(-ENOMEM);
Michael Halcrow237fead2006-10-04 02:16:22 -0700728 goto out;
729 }
730 old_fs = get_fs();
731 set_fs(get_ds());
Michael Halcrow237fead2006-10-04 02:16:22 -0700732 rc = dentry->d_inode->i_op->readlink(dentry, (char __user *)buf, len);
Michael Halcrow237fead2006-10-04 02:16:22 -0700733 set_fs(old_fs);
OGAWA Hirofumi806892e2010-01-12 03:36:14 +0900734 if (rc < 0) {
735 kfree(buf);
736 buf = ERR_PTR(rc);
737 } else
Duane Griffina17d5232008-12-19 20:47:10 +0000738 buf[rc] = '\0';
Michael Halcrow237fead2006-10-04 02:16:22 -0700739out:
OGAWA Hirofumi806892e2010-01-12 03:36:14 +0900740 nd_set_link(nd, buf);
741 return NULL;
Michael Halcrow237fead2006-10-04 02:16:22 -0700742}
743
744static void
745ecryptfs_put_link(struct dentry *dentry, struct nameidata *nd, void *ptr)
746{
OGAWA Hirofumi806892e2010-01-12 03:36:14 +0900747 char *buf = nd_get_link(nd);
748 if (!IS_ERR(buf)) {
749 /* Free the char* */
750 kfree(buf);
751 }
Michael Halcrow237fead2006-10-04 02:16:22 -0700752}
753
754/**
755 * upper_size_to_lower_size
756 * @crypt_stat: Crypt_stat associated with file
757 * @upper_size: Size of the upper file
758 *
Michael Halcrowcc11bef2008-02-06 01:38:32 -0800759 * Calculate the required size of the lower file based on the
Michael Halcrow237fead2006-10-04 02:16:22 -0700760 * specified size of the upper file. This calculation is based on the
761 * number of headers in the underlying file and the extent size.
762 *
763 * Returns Calculated size of the lower file.
764 */
765static loff_t
766upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
767 loff_t upper_size)
768{
769 loff_t lower_size;
770
Michael Halcrowcc11bef2008-02-06 01:38:32 -0800771 lower_size = crypt_stat->num_header_bytes_at_front;
Michael Halcrow237fead2006-10-04 02:16:22 -0700772 if (upper_size != 0) {
773 loff_t num_extents;
774
775 num_extents = upper_size >> crypt_stat->extent_shift;
776 if (upper_size & ~crypt_stat->extent_mask)
777 num_extents++;
778 lower_size += (num_extents * crypt_stat->extent_size);
779 }
780 return lower_size;
781}
782
783/**
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500784 * truncate_upper
Michael Halcrow237fead2006-10-04 02:16:22 -0700785 * @dentry: The ecryptfs layer dentry
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500786 * @ia: Address of the ecryptfs inode's attributes
787 * @lower_ia: Address of the lower inode's attributes
Michael Halcrow237fead2006-10-04 02:16:22 -0700788 *
789 * Function to handle truncations modifying the size of the file. Note
790 * that the file sizes are interpolated. When expanding, we are simply
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500791 * writing strings of 0's out. When truncating, we truncate the upper
792 * inode and update the lower_ia according to the page index
793 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
794 * the caller must use lower_ia in a call to notify_change() to perform
795 * the truncation of the lower inode.
Michael Halcrow237fead2006-10-04 02:16:22 -0700796 *
797 * Returns zero on success; non-zero otherwise
798 */
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500799static int truncate_upper(struct dentry *dentry, struct iattr *ia,
800 struct iattr *lower_ia)
Michael Halcrow237fead2006-10-04 02:16:22 -0700801{
802 int rc = 0;
803 struct inode *inode = dentry->d_inode;
804 struct dentry *lower_dentry;
Michael Halcrow2ed92552007-10-16 01:28:10 -0700805 struct file fake_ecryptfs_file;
Michael Halcrow237fead2006-10-04 02:16:22 -0700806 struct ecryptfs_crypt_stat *crypt_stat;
807 loff_t i_size = i_size_read(inode);
808 loff_t lower_size_before_truncate;
809 loff_t lower_size_after_truncate;
810
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500811 if (unlikely((ia->ia_size == i_size))) {
812 lower_ia->ia_valid &= ~ATTR_SIZE;
Michael Halcrow237fead2006-10-04 02:16:22 -0700813 goto out;
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500814 }
Michael Halcrow237fead2006-10-04 02:16:22 -0700815 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
816 /* Set up a fake ecryptfs file, this is used to interface with
817 * the file in the underlying filesystem so that the
818 * truncation has an effect there as well. */
819 memset(&fake_ecryptfs_file, 0, sizeof(fake_ecryptfs_file));
Josef "Jeff" Sipekbd243a42006-12-08 02:36:48 -0800820 fake_ecryptfs_file.f_path.dentry = dentry;
Michael Halcrow237fead2006-10-04 02:16:22 -0700821 /* Released at out_free: label */
822 ecryptfs_set_file_private(&fake_ecryptfs_file,
823 kmem_cache_alloc(ecryptfs_file_info_cache,
Christoph Lametere94b1762006-12-06 20:33:17 -0800824 GFP_KERNEL));
Michael Halcrow237fead2006-10-04 02:16:22 -0700825 if (unlikely(!ecryptfs_file_to_private(&fake_ecryptfs_file))) {
826 rc = -ENOMEM;
827 goto out;
828 }
829 lower_dentry = ecryptfs_dentry_to_lower(dentry);
Michael Halcrow2ed92552007-10-16 01:28:10 -0700830 ecryptfs_set_file_lower(
831 &fake_ecryptfs_file,
832 ecryptfs_inode_to_private(dentry->d_inode)->lower_file);
Michael Halcrow237fead2006-10-04 02:16:22 -0700833 /* Switch on growing or shrinking file */
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500834 if (ia->ia_size > i_size) {
Michael Halcrow2ed92552007-10-16 01:28:10 -0700835 char zero[] = { 0x00 };
Michael Halcrow240e2df2007-06-27 14:09:44 -0700836
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500837 lower_ia->ia_valid &= ~ATTR_SIZE;
Michael Halcrow2ed92552007-10-16 01:28:10 -0700838 /* Write a single 0 at the last position of the file;
839 * this triggers code that will fill in 0's throughout
840 * the intermediate portion of the previous end of the
841 * file and the new and of the file */
842 rc = ecryptfs_write(&fake_ecryptfs_file, zero,
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500843 (ia->ia_size - 1), 1);
844 } else { /* ia->ia_size < i_size_read(inode) */
845 /* We're chopping off all the pages down to the page
846 * in which ia->ia_size is located. Fill in the end of
847 * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
Michael Halcrow2ed92552007-10-16 01:28:10 -0700848 * PAGE_CACHE_SIZE with zeros. */
849 size_t num_zeros = (PAGE_CACHE_SIZE
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500850 - (ia->ia_size & ~PAGE_CACHE_MASK));
Michael Halcrow2ed92552007-10-16 01:28:10 -0700851
Tyler Hicks13a791b2009-04-13 15:29:27 -0500852 if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500853 rc = vmtruncate(inode, ia->ia_size);
Tyler Hicks13a791b2009-04-13 15:29:27 -0500854 if (rc)
855 goto out_free;
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500856 lower_ia->ia_size = ia->ia_size;
857 lower_ia->ia_valid |= ATTR_SIZE;
Tyler Hicks13a791b2009-04-13 15:29:27 -0500858 goto out_free;
859 }
Michael Halcrow2ed92552007-10-16 01:28:10 -0700860 if (num_zeros) {
861 char *zeros_virt;
862
863 zeros_virt = kzalloc(num_zeros, GFP_KERNEL);
864 if (!zeros_virt) {
865 rc = -ENOMEM;
866 goto out_free;
867 }
868 rc = ecryptfs_write(&fake_ecryptfs_file, zeros_virt,
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500869 ia->ia_size, num_zeros);
Michael Halcrow2ed92552007-10-16 01:28:10 -0700870 kfree(zeros_virt);
Michael Halcrow5dda6992007-10-16 01:28:06 -0700871 if (rc) {
Michael Halcrow240e2df2007-06-27 14:09:44 -0700872 printk(KERN_ERR "Error attempting to zero out "
873 "the remainder of the end page on "
874 "reducing truncate; rc = [%d]\n", rc);
Michael Halcrow2ed92552007-10-16 01:28:10 -0700875 goto out_free;
Michael Halcrow240e2df2007-06-27 14:09:44 -0700876 }
877 }
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500878 vmtruncate(inode, ia->ia_size);
Michael Halcrow0216f7f2007-10-16 01:28:08 -0700879 rc = ecryptfs_write_inode_size_to_metadata(inode);
Michael Halcrowdd2a3b72007-02-12 00:53:46 -0800880 if (rc) {
881 printk(KERN_ERR "Problem with "
882 "ecryptfs_write_inode_size_to_metadata; "
883 "rc = [%d]\n", rc);
Michael Halcrow2ed92552007-10-16 01:28:10 -0700884 goto out_free;
Michael Halcrowdd2a3b72007-02-12 00:53:46 -0800885 }
Michael Halcrow237fead2006-10-04 02:16:22 -0700886 /* We are reducing the size of the ecryptfs file, and need to
887 * know if we need to reduce the size of the lower file. */
888 lower_size_before_truncate =
889 upper_size_to_lower_size(crypt_stat, i_size);
890 lower_size_after_truncate =
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500891 upper_size_to_lower_size(crypt_stat, ia->ia_size);
892 if (lower_size_after_truncate < lower_size_before_truncate) {
893 lower_ia->ia_size = lower_size_after_truncate;
894 lower_ia->ia_valid |= ATTR_SIZE;
895 } else
896 lower_ia->ia_valid &= ~ATTR_SIZE;
Michael Halcrow237fead2006-10-04 02:16:22 -0700897 }
Michael Halcrow237fead2006-10-04 02:16:22 -0700898out_free:
899 if (ecryptfs_file_to_private(&fake_ecryptfs_file))
900 kmem_cache_free(ecryptfs_file_info_cache,
901 ecryptfs_file_to_private(&fake_ecryptfs_file));
902out:
903 return rc;
904}
905
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500906/**
907 * ecryptfs_truncate
908 * @dentry: The ecryptfs layer dentry
909 * @new_length: The length to expand the file to
910 *
911 * Simple function that handles the truncation of an eCryptfs inode and
912 * its corresponding lower inode.
913 *
914 * Returns zero on success; non-zero otherwise
915 */
916int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
917{
918 struct iattr ia = { .ia_valid = ATTR_SIZE, .ia_size = new_length };
919 struct iattr lower_ia = { .ia_valid = 0 };
920 int rc;
921
922 rc = truncate_upper(dentry, &ia, &lower_ia);
923 if (!rc && lower_ia.ia_valid & ATTR_SIZE) {
924 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
925
926 mutex_lock(&lower_dentry->d_inode->i_mutex);
927 rc = notify_change(lower_dentry, &lower_ia);
928 mutex_unlock(&lower_dentry->d_inode->i_mutex);
929 }
930 return rc;
931}
932
Michael Halcrow237fead2006-10-04 02:16:22 -0700933static int
Al Viroe6305c42008-07-15 21:03:57 -0400934ecryptfs_permission(struct inode *inode, int mask)
Michael Halcrow237fead2006-10-04 02:16:22 -0700935{
Al Virof419a2e2008-07-22 00:07:17 -0400936 return inode_permission(ecryptfs_inode_to_lower(inode), mask);
Michael Halcrow237fead2006-10-04 02:16:22 -0700937}
938
939/**
940 * ecryptfs_setattr
941 * @dentry: dentry handle to the inode to modify
942 * @ia: Structure with flags of what to change and values
943 *
944 * Updates the metadata of an inode. If the update is to the size
945 * i.e. truncation, then ecryptfs_truncate will handle the size modification
946 * of both the ecryptfs inode and the lower inode.
947 *
948 * All other metadata changes will be passed right to the lower filesystem,
949 * and we will just update our inode to look like the lower.
950 */
951static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
952{
953 int rc = 0;
954 struct dentry *lower_dentry;
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500955 struct iattr lower_ia;
Michael Halcrow237fead2006-10-04 02:16:22 -0700956 struct inode *inode;
957 struct inode *lower_inode;
958 struct ecryptfs_crypt_stat *crypt_stat;
959
960 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
Michael Halcrowe10f2812007-06-27 14:09:44 -0700961 if (!(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED))
962 ecryptfs_init_crypt_stat(crypt_stat);
Michael Halcrow237fead2006-10-04 02:16:22 -0700963 inode = dentry->d_inode;
964 lower_inode = ecryptfs_inode_to_lower(inode);
Michael Halcrowe10f2812007-06-27 14:09:44 -0700965 lower_dentry = ecryptfs_dentry_to_lower(dentry);
966 mutex_lock(&crypt_stat->cs_mutex);
967 if (S_ISDIR(dentry->d_inode->i_mode))
968 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
Michael Halcrow64ee4802007-07-19 01:47:54 -0700969 else if (S_ISREG(dentry->d_inode->i_mode)
970 && (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
971 || !(crypt_stat->flags & ECRYPTFS_KEY_VALID))) {
Michael Halcrowe10f2812007-06-27 14:09:44 -0700972 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
Michael Halcrowe10f2812007-06-27 14:09:44 -0700973
Michael Halcrowe10f2812007-06-27 14:09:44 -0700974 mount_crypt_stat = &ecryptfs_superblock_to_private(
975 dentry->d_sb)->mount_crypt_stat;
Michael Halcrowd7cdc5f2007-10-16 01:28:10 -0700976 rc = ecryptfs_read_metadata(dentry);
Michael Halcrow5dda6992007-10-16 01:28:06 -0700977 if (rc) {
Michael Halcrowe10f2812007-06-27 14:09:44 -0700978 if (!(mount_crypt_stat->flags
979 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
980 rc = -EIO;
Michael Halcrow25bd8172008-02-06 01:38:35 -0800981 printk(KERN_WARNING "Either the lower file "
Michael Halcrowe10f2812007-06-27 14:09:44 -0700982 "is not in a valid eCryptfs format, "
Michael Halcrow25bd8172008-02-06 01:38:35 -0800983 "or the key could not be retrieved. "
984 "Plaintext passthrough mode is not "
Michael Halcrowe10f2812007-06-27 14:09:44 -0700985 "enabled; returning -EIO\n");
Michael Halcrowe10f2812007-06-27 14:09:44 -0700986 mutex_unlock(&crypt_stat->cs_mutex);
Michael Halcrowe10f2812007-06-27 14:09:44 -0700987 goto out;
988 }
989 rc = 0;
990 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
Michael Halcrowe10f2812007-06-27 14:09:44 -0700991 }
Michael Halcrowe10f2812007-06-27 14:09:44 -0700992 }
993 mutex_unlock(&crypt_stat->cs_mutex);
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500994 memcpy(&lower_ia, ia, sizeof(lower_ia));
995 if (ia->ia_valid & ATTR_FILE)
996 lower_ia.ia_file = ecryptfs_file_to_lower(ia->ia_file);
Michael Halcrow237fead2006-10-04 02:16:22 -0700997 if (ia->ia_valid & ATTR_SIZE) {
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500998 rc = truncate_upper(dentry, ia, &lower_ia);
Michael Halcrow237fead2006-10-04 02:16:22 -0700999 if (rc < 0)
1000 goto out;
1001 }
Jeff Layton1ac564e2007-10-18 03:05:17 -07001002
1003 /*
1004 * mode change is for clearing setuid/setgid bits. Allow lower fs
1005 * to interpret this in its own way.
1006 */
Tyler Hicks5f3ef642009-10-14 16:18:27 -05001007 if (lower_ia.ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
1008 lower_ia.ia_valid &= ~ATTR_MODE;
Jeff Layton1ac564e2007-10-18 03:05:17 -07001009
Miklos Szeredi9c3580a2008-04-29 00:59:48 -07001010 mutex_lock(&lower_dentry->d_inode->i_mutex);
Tyler Hicks5f3ef642009-10-14 16:18:27 -05001011 rc = notify_change(lower_dentry, &lower_ia);
Miklos Szeredi9c3580a2008-04-29 00:59:48 -07001012 mutex_unlock(&lower_dentry->d_inode->i_mutex);
Michael Halcrow237fead2006-10-04 02:16:22 -07001013out:
Erez Zadok9afa2fb2009-12-02 19:51:54 -05001014 fsstack_copy_attr_all(inode, lower_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -07001015 return rc;
1016}
1017
Tyler Hicksf8f484d2009-11-04 02:48:01 -06001018int ecryptfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
1019 struct kstat *stat)
1020{
1021 struct kstat lower_stat;
1022 int rc;
1023
1024 rc = vfs_getattr(ecryptfs_dentry_to_lower_mnt(dentry),
1025 ecryptfs_dentry_to_lower(dentry), &lower_stat);
1026 if (!rc) {
1027 generic_fillattr(dentry->d_inode, stat);
1028 stat->blocks = lower_stat.blocks;
1029 }
1030 return rc;
1031}
1032
Michael Halcrowdd2a3b72007-02-12 00:53:46 -08001033int
Michael Halcrow237fead2006-10-04 02:16:22 -07001034ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value,
1035 size_t size, int flags)
1036{
1037 int rc = 0;
1038 struct dentry *lower_dentry;
1039
1040 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1041 if (!lower_dentry->d_inode->i_op->setxattr) {
1042 rc = -ENOSYS;
1043 goto out;
1044 }
1045 mutex_lock(&lower_dentry->d_inode->i_mutex);
1046 rc = lower_dentry->d_inode->i_op->setxattr(lower_dentry, name, value,
1047 size, flags);
1048 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1049out:
1050 return rc;
1051}
1052
Michael Halcrowdd2a3b72007-02-12 00:53:46 -08001053ssize_t
Michael Halcrowd7cdc5f2007-10-16 01:28:10 -07001054ecryptfs_getxattr_lower(struct dentry *lower_dentry, const char *name,
1055 void *value, size_t size)
1056{
1057 int rc = 0;
1058
1059 if (!lower_dentry->d_inode->i_op->getxattr) {
1060 rc = -ENOSYS;
1061 goto out;
1062 }
1063 mutex_lock(&lower_dentry->d_inode->i_mutex);
1064 rc = lower_dentry->d_inode->i_op->getxattr(lower_dentry, name, value,
1065 size);
1066 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1067out:
1068 return rc;
1069}
1070
Adrian Bunk7896b632008-02-06 01:38:32 -08001071static ssize_t
Michael Halcrow237fead2006-10-04 02:16:22 -07001072ecryptfs_getxattr(struct dentry *dentry, const char *name, void *value,
1073 size_t size)
1074{
Michael Halcrow2ed92552007-10-16 01:28:10 -07001075 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry), name,
1076 value, size);
Michael Halcrow237fead2006-10-04 02:16:22 -07001077}
1078
1079static ssize_t
1080ecryptfs_listxattr(struct dentry *dentry, char *list, size_t size)
1081{
1082 int rc = 0;
1083 struct dentry *lower_dentry;
1084
1085 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1086 if (!lower_dentry->d_inode->i_op->listxattr) {
1087 rc = -ENOSYS;
1088 goto out;
1089 }
1090 mutex_lock(&lower_dentry->d_inode->i_mutex);
1091 rc = lower_dentry->d_inode->i_op->listxattr(lower_dentry, list, size);
1092 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1093out:
1094 return rc;
1095}
1096
1097static int ecryptfs_removexattr(struct dentry *dentry, const char *name)
1098{
1099 int rc = 0;
1100 struct dentry *lower_dentry;
1101
1102 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1103 if (!lower_dentry->d_inode->i_op->removexattr) {
1104 rc = -ENOSYS;
1105 goto out;
1106 }
1107 mutex_lock(&lower_dentry->d_inode->i_mutex);
1108 rc = lower_dentry->d_inode->i_op->removexattr(lower_dentry, name);
1109 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1110out:
1111 return rc;
1112}
1113
1114int ecryptfs_inode_test(struct inode *inode, void *candidate_lower_inode)
1115{
1116 if ((ecryptfs_inode_to_lower(inode)
1117 == (struct inode *)candidate_lower_inode))
1118 return 1;
1119 else
1120 return 0;
1121}
1122
1123int ecryptfs_inode_set(struct inode *inode, void *lower_inode)
1124{
1125 ecryptfs_init_inode(inode, (struct inode *)lower_inode);
1126 return 0;
1127}
1128
Arjan van de Ven754661f2007-02-12 00:55:38 -08001129const struct inode_operations ecryptfs_symlink_iops = {
Michael Halcrow237fead2006-10-04 02:16:22 -07001130 .readlink = ecryptfs_readlink,
1131 .follow_link = ecryptfs_follow_link,
1132 .put_link = ecryptfs_put_link,
1133 .permission = ecryptfs_permission,
1134 .setattr = ecryptfs_setattr,
1135 .setxattr = ecryptfs_setxattr,
1136 .getxattr = ecryptfs_getxattr,
1137 .listxattr = ecryptfs_listxattr,
1138 .removexattr = ecryptfs_removexattr
1139};
1140
Arjan van de Ven754661f2007-02-12 00:55:38 -08001141const struct inode_operations ecryptfs_dir_iops = {
Michael Halcrow237fead2006-10-04 02:16:22 -07001142 .create = ecryptfs_create,
1143 .lookup = ecryptfs_lookup,
1144 .link = ecryptfs_link,
1145 .unlink = ecryptfs_unlink,
1146 .symlink = ecryptfs_symlink,
1147 .mkdir = ecryptfs_mkdir,
1148 .rmdir = ecryptfs_rmdir,
1149 .mknod = ecryptfs_mknod,
1150 .rename = ecryptfs_rename,
1151 .permission = ecryptfs_permission,
1152 .setattr = ecryptfs_setattr,
1153 .setxattr = ecryptfs_setxattr,
1154 .getxattr = ecryptfs_getxattr,
1155 .listxattr = ecryptfs_listxattr,
1156 .removexattr = ecryptfs_removexattr
1157};
1158
Arjan van de Ven754661f2007-02-12 00:55:38 -08001159const struct inode_operations ecryptfs_main_iops = {
Michael Halcrow237fead2006-10-04 02:16:22 -07001160 .permission = ecryptfs_permission,
1161 .setattr = ecryptfs_setattr,
Tyler Hicksf8f484d2009-11-04 02:48:01 -06001162 .getattr = ecryptfs_getattr,
Michael Halcrow237fead2006-10-04 02:16:22 -07001163 .setxattr = ecryptfs_setxattr,
1164 .getxattr = ecryptfs_getxattr,
1165 .listxattr = ecryptfs_listxattr,
1166 .removexattr = ecryptfs_removexattr
1167};