blob: 67e9b6339691f9cc01a378564fa5aa0527da1977 [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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090034#include <linux/slab.h>
Roberto Sassu48b512e2010-10-05 18:53:45 +020035#include <linux/xattr.h>
Harvey Harrison0a688ad2008-07-23 21:30:07 -070036#include <asm/unaligned.h>
Michael Halcrow237fead2006-10-04 02:16:22 -070037#include "ecryptfs_kernel.h"
38
39static struct dentry *lock_parent(struct dentry *dentry)
40{
41 struct dentry *dir;
42
Miklos Szeredi8dc4e372008-05-12 14:02:04 -070043 dir = dget_parent(dentry);
Peter Zijlstra908e0a82007-03-07 20:41:30 -080044 mutex_lock_nested(&(dir->d_inode->i_mutex), I_MUTEX_PARENT);
Michael Halcrow237fead2006-10-04 02:16:22 -070045 return dir;
46}
47
Michael Halcrow237fead2006-10-04 02:16:22 -070048static void unlock_dir(struct dentry *dir)
49{
50 mutex_unlock(&dir->d_inode->i_mutex);
51 dput(dir);
52}
53
Tyler Hicksc4f79072011-05-23 21:18:20 -050054static int ecryptfs_inode_test(struct inode *inode, void *lower_inode)
55{
56 if (ecryptfs_inode_to_lower(inode) == (struct inode *)lower_inode)
57 return 1;
58 return 0;
59}
60
Tyler Hicks5ccf9202011-05-24 02:16:51 -050061static int ecryptfs_inode_set(struct inode *inode, void *opaque)
Tyler Hicksc4f79072011-05-23 21:18:20 -050062{
Tyler Hicks5ccf9202011-05-24 02:16:51 -050063 struct inode *lower_inode = opaque;
64
65 ecryptfs_set_inode_lower(inode, lower_inode);
66 fsstack_copy_attr_all(inode, lower_inode);
67 /* i_size will be overwritten for encrypted regular files */
68 fsstack_copy_inode_size(inode, lower_inode);
69 inode->i_ino = lower_inode->i_ino;
Tyler Hicksc4f79072011-05-23 21:18:20 -050070 inode->i_version++;
Tyler Hicksc4f79072011-05-23 21:18:20 -050071 inode->i_mapping->a_ops = &ecryptfs_aops;
Thieu Le985ca0e2011-07-26 16:15:10 -070072 inode->i_mapping->backing_dev_info = inode->i_sb->s_bdi;
Tyler Hicks5ccf9202011-05-24 02:16:51 -050073
74 if (S_ISLNK(inode->i_mode))
75 inode->i_op = &ecryptfs_symlink_iops;
76 else if (S_ISDIR(inode->i_mode))
77 inode->i_op = &ecryptfs_dir_iops;
78 else
79 inode->i_op = &ecryptfs_main_iops;
80
81 if (S_ISDIR(inode->i_mode))
82 inode->i_fop = &ecryptfs_dir_fops;
83 else if (special_file(inode->i_mode))
84 init_special_inode(inode, inode->i_mode, inode->i_rdev);
85 else
86 inode->i_fop = &ecryptfs_main_fops;
87
Tyler Hicksc4f79072011-05-23 21:18:20 -050088 return 0;
89}
90
Tyler Hicks5ccf9202011-05-24 02:16:51 -050091static struct inode *__ecryptfs_get_inode(struct inode *lower_inode,
92 struct super_block *sb)
93{
94 struct inode *inode;
95
96 if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb))
97 return ERR_PTR(-EXDEV);
98 if (!igrab(lower_inode))
99 return ERR_PTR(-ESTALE);
100 inode = iget5_locked(sb, (unsigned long)lower_inode,
101 ecryptfs_inode_test, ecryptfs_inode_set,
102 lower_inode);
103 if (!inode) {
104 iput(lower_inode);
105 return ERR_PTR(-EACCES);
106 }
107 if (!(inode->i_state & I_NEW))
108 iput(lower_inode);
109
110 return inode;
111}
112
Tyler Hicksc4f79072011-05-23 21:18:20 -0500113struct inode *ecryptfs_get_inode(struct inode *lower_inode,
114 struct super_block *sb)
115{
Tyler Hicks5ccf9202011-05-24 02:16:51 -0500116 struct inode *inode = __ecryptfs_get_inode(lower_inode, sb);
Tyler Hicksc4f79072011-05-23 21:18:20 -0500117
Tyler Hicks5ccf9202011-05-24 02:16:51 -0500118 if (!IS_ERR(inode) && (inode->i_state & I_NEW))
Tyler Hicksc4f79072011-05-23 21:18:20 -0500119 unlock_new_inode(inode);
Tyler Hicks5ccf9202011-05-24 02:16:51 -0500120
Tyler Hicksc4f79072011-05-23 21:18:20 -0500121 return inode;
Tyler Hicksc4f79072011-05-23 21:18:20 -0500122}
123
Tyler Hicksc4f79072011-05-23 21:18:20 -0500124/**
125 * ecryptfs_interpose
126 * @lower_dentry: Existing dentry in the lower filesystem
127 * @dentry: ecryptfs' dentry
128 * @sb: ecryptfs's super_block
Tyler Hicksc4f79072011-05-23 21:18:20 -0500129 *
130 * Interposes upper and lower dentries.
131 *
132 * Returns zero on success; non-zero otherwise
133 */
134static int ecryptfs_interpose(struct dentry *lower_dentry,
Tyler Hicks5ccf9202011-05-24 02:16:51 -0500135 struct dentry *dentry, struct super_block *sb)
Tyler Hicksc4f79072011-05-23 21:18:20 -0500136{
Tyler Hicks5ccf9202011-05-24 02:16:51 -0500137 struct inode *inode = ecryptfs_get_inode(lower_dentry->d_inode, sb);
138
Tyler Hicksc4f79072011-05-23 21:18:20 -0500139 if (IS_ERR(inode))
140 return PTR_ERR(inode);
Tyler Hicks5ccf9202011-05-24 02:16:51 -0500141 d_instantiate(dentry, inode);
142
Tyler Hicksc4f79072011-05-23 21:18:20 -0500143 return 0;
144}
145
Tyler Hicks8bc2d3c2012-05-22 15:09:50 -0500146static int ecryptfs_do_unlink(struct inode *dir, struct dentry *dentry,
147 struct inode *inode)
148{
149 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
150 struct inode *lower_dir_inode = ecryptfs_inode_to_lower(dir);
151 struct dentry *lower_dir_dentry;
152 int rc;
153
154 dget(lower_dentry);
155 lower_dir_dentry = lock_parent(lower_dentry);
156 rc = vfs_unlink(lower_dir_inode, lower_dentry);
157 if (rc) {
158 printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc);
159 goto out_unlock;
160 }
161 fsstack_copy_attr_times(dir, lower_dir_inode);
162 set_nlink(inode, ecryptfs_inode_to_lower(inode)->i_nlink);
163 inode->i_ctime = dir->i_ctime;
164 d_drop(dentry);
165out_unlock:
166 unlock_dir(lower_dir_dentry);
167 dput(lower_dentry);
168 return rc;
169}
170
Michael Halcrow237fead2006-10-04 02:16:22 -0700171/**
Michael Halcrow237fead2006-10-04 02:16:22 -0700172 * ecryptfs_do_create
173 * @directory_inode: inode of the new file's dentry's parent in ecryptfs
174 * @ecryptfs_dentry: New file's dentry in ecryptfs
175 * @mode: The mode of the new file
176 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
177 *
178 * Creates the underlying file and the eCryptfs inode which will link to
179 * it. It will also update the eCryptfs directory inode to mimic the
180 * stat of the lower directory inode.
181 *
Tyler Hicksb59db432011-11-21 17:31:02 -0600182 * Returns the new eCryptfs inode on success; an ERR_PTR on error condition
Michael Halcrow237fead2006-10-04 02:16:22 -0700183 */
Tyler Hicksb59db432011-11-21 17:31:02 -0600184static struct inode *
Michael Halcrow237fead2006-10-04 02:16:22 -0700185ecryptfs_do_create(struct inode *directory_inode,
Al Viro175a4eb2011-07-26 03:30:54 -0400186 struct dentry *ecryptfs_dentry, umode_t mode)
Michael Halcrow237fead2006-10-04 02:16:22 -0700187{
188 int rc;
189 struct dentry *lower_dentry;
190 struct dentry *lower_dir_dentry;
Tyler Hicksb59db432011-11-21 17:31:02 -0600191 struct inode *inode;
Michael Halcrow237fead2006-10-04 02:16:22 -0700192
193 lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
194 lower_dir_dentry = lock_parent(lower_dentry);
Hirofumi Nakagawa801678c2008-04-29 01:03:09 -0700195 if (IS_ERR(lower_dir_dentry)) {
Michael Halcrow237fead2006-10-04 02:16:22 -0700196 ecryptfs_printk(KERN_ERR, "Error locking directory of "
197 "dentry\n");
Tyler Hicksb59db432011-11-21 17:31:02 -0600198 inode = ERR_CAST(lower_dir_dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -0700199 goto out;
200 }
Al Viro312b63f2012-06-10 18:09:36 -0400201 rc = vfs_create(lower_dir_dentry->d_inode, lower_dentry, mode, true);
Michael Halcrow4981e082007-10-16 01:28:09 -0700202 if (rc) {
Michael Halcrowcaeeeec2008-01-08 15:33:02 -0800203 printk(KERN_ERR "%s: Failure to create dentry in lower fs; "
Harvey Harrison18d1dbf2008-04-29 00:59:48 -0700204 "rc = [%d]\n", __func__, rc);
Tyler Hicksb59db432011-11-21 17:31:02 -0600205 inode = ERR_PTR(rc);
Michael Halcrowcaeeeec2008-01-08 15:33:02 -0800206 goto out_lock;
Michael Halcrow237fead2006-10-04 02:16:22 -0700207 }
Tyler Hicksb59db432011-11-21 17:31:02 -0600208 inode = __ecryptfs_get_inode(lower_dentry->d_inode,
209 directory_inode->i_sb);
Tyler Hicks8bc2d3c2012-05-22 15:09:50 -0500210 if (IS_ERR(inode)) {
211 vfs_unlink(lower_dir_dentry->d_inode, lower_dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -0700212 goto out_lock;
Tyler Hicks8bc2d3c2012-05-22 15:09:50 -0500213 }
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -0800214 fsstack_copy_attr_times(directory_inode, lower_dir_dentry->d_inode);
215 fsstack_copy_inode_size(directory_inode, lower_dir_dentry->d_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700216out_lock:
217 unlock_dir(lower_dir_dentry);
218out:
Tyler Hicksb59db432011-11-21 17:31:02 -0600219 return inode;
Michael Halcrow237fead2006-10-04 02:16:22 -0700220}
221
222/**
Michael Halcrow237fead2006-10-04 02:16:22 -0700223 * ecryptfs_initialize_file
224 *
225 * Cause the file to be changed from a basic empty file to an ecryptfs
226 * file with a header and first data page.
227 *
228 * Returns zero on success
229 */
Tyler Hickse3ccaa92012-06-20 23:50:59 -0700230int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry,
231 struct inode *ecryptfs_inode)
Michael Halcrow237fead2006-10-04 02:16:22 -0700232{
Michael Halcrowd7cdc5f2007-10-16 01:28:10 -0700233 struct ecryptfs_crypt_stat *crypt_stat =
Tyler Hicksb59db432011-11-21 17:31:02 -0600234 &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat;
Michael Halcrow237fead2006-10-04 02:16:22 -0700235 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -0700236
Tyler Hicksb59db432011-11-21 17:31:02 -0600237 if (S_ISDIR(ecryptfs_inode->i_mode)) {
Michael Halcrow237fead2006-10-04 02:16:22 -0700238 ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
Michael Halcrowe2bd99e2007-02-12 00:53:49 -0800239 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
Michael Halcrowd7cdc5f2007-10-16 01:28:10 -0700240 goto out;
Michael Halcrow237fead2006-10-04 02:16:22 -0700241 }
Michael Halcrow237fead2006-10-04 02:16:22 -0700242 ecryptfs_printk(KERN_DEBUG, "Initializing crypto context\n");
Tyler Hicksb59db432011-11-21 17:31:02 -0600243 rc = ecryptfs_new_file_context(ecryptfs_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700244 if (rc) {
Michael Halcrowd7cdc5f2007-10-16 01:28:10 -0700245 ecryptfs_printk(KERN_ERR, "Error creating new file "
246 "context; rc = [%d]\n", rc);
247 goto out;
Michael Halcrow237fead2006-10-04 02:16:22 -0700248 }
Tyler Hicksb59db432011-11-21 17:31:02 -0600249 rc = ecryptfs_get_lower_file(ecryptfs_dentry, ecryptfs_inode);
Roberto Sassu27992892010-11-03 11:11:28 +0100250 if (rc) {
251 printk(KERN_ERR "%s: Error attempting to initialize "
Tyler Hicks332ab162011-04-14 15:35:11 -0500252 "the lower file for the dentry with name "
Roberto Sassu27992892010-11-03 11:11:28 +0100253 "[%s]; rc = [%d]\n", __func__,
254 ecryptfs_dentry->d_name.name, rc);
255 goto out;
Michael Halcrow391b52f2008-07-23 21:30:08 -0700256 }
Tyler Hicksb59db432011-11-21 17:31:02 -0600257 rc = ecryptfs_write_metadata(ecryptfs_dentry, ecryptfs_inode);
Tyler Hicks332ab162011-04-14 15:35:11 -0500258 if (rc)
Michael Halcrowd7cdc5f2007-10-16 01:28:10 -0700259 printk(KERN_ERR "Error writing headers; rc = [%d]\n", rc);
Tyler Hicksb59db432011-11-21 17:31:02 -0600260 ecryptfs_put_lower_file(ecryptfs_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700261out:
262 return rc;
263}
264
265/**
266 * ecryptfs_create
267 * @dir: The inode of the directory in which to create the file.
268 * @dentry: The eCryptfs dentry
269 * @mode: The mode of the new file.
Michael Halcrow237fead2006-10-04 02:16:22 -0700270 *
271 * Creates a new file.
272 *
273 * Returns zero on success; non-zero on error condition
274 */
275static int
276ecryptfs_create(struct inode *directory_inode, struct dentry *ecryptfs_dentry,
Al Viroebfc3b42012-06-10 18:05:36 -0400277 umode_t mode, bool excl)
Michael Halcrow237fead2006-10-04 02:16:22 -0700278{
Tyler Hicksb59db432011-11-21 17:31:02 -0600279 struct inode *ecryptfs_inode;
Michael Halcrow237fead2006-10-04 02:16:22 -0700280 int rc;
281
Tyler Hicksb59db432011-11-21 17:31:02 -0600282 ecryptfs_inode = ecryptfs_do_create(directory_inode, ecryptfs_dentry,
283 mode);
284 if (unlikely(IS_ERR(ecryptfs_inode))) {
Michael Halcrow237fead2006-10-04 02:16:22 -0700285 ecryptfs_printk(KERN_WARNING, "Failed to create file in"
286 "lower filesystem\n");
Tyler Hicksb59db432011-11-21 17:31:02 -0600287 rc = PTR_ERR(ecryptfs_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700288 goto out;
289 }
290 /* At this point, a file exists on "disk"; we need to make sure
291 * that this on disk file is prepared to be an ecryptfs file */
Tyler Hicksb59db432011-11-21 17:31:02 -0600292 rc = ecryptfs_initialize_file(ecryptfs_dentry, ecryptfs_inode);
293 if (rc) {
Tyler Hicks8bc2d3c2012-05-22 15:09:50 -0500294 ecryptfs_do_unlink(directory_inode, ecryptfs_dentry,
295 ecryptfs_inode);
296 make_bad_inode(ecryptfs_inode);
Tyler Hicksb59db432011-11-21 17:31:02 -0600297 unlock_new_inode(ecryptfs_inode);
298 iput(ecryptfs_inode);
299 goto out;
300 }
Tyler Hicksb59db432011-11-21 17:31:02 -0600301 unlock_new_inode(ecryptfs_inode);
Al Viro8fc37ec2012-07-19 09:18:15 +0400302 d_instantiate(ecryptfs_dentry, ecryptfs_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700303out:
304 return rc;
305}
306
Tyler Hicks778aeb42011-05-24 04:56:23 -0500307static int ecryptfs_i_size_read(struct dentry *dentry, struct inode *inode)
Michael Halcrow237fead2006-10-04 02:16:22 -0700308{
Tyler Hicks2aac0cf2009-03-20 02:23:57 -0500309 struct ecryptfs_crypt_stat *crypt_stat;
Tyler Hicks778aeb42011-05-24 04:56:23 -0500310 int rc;
Michael Halcrow237fead2006-10-04 02:16:22 -0700311
Tyler Hicks778aeb42011-05-24 04:56:23 -0500312 rc = ecryptfs_get_lower_file(dentry, inode);
Roberto Sassu27992892010-11-03 11:11:28 +0100313 if (rc) {
314 printk(KERN_ERR "%s: Error attempting to initialize "
Tyler Hicks332ab162011-04-14 15:35:11 -0500315 "the lower file for the dentry with name "
Roberto Sassu27992892010-11-03 11:11:28 +0100316 "[%s]; rc = [%d]\n", __func__,
Tyler Hicks778aeb42011-05-24 04:56:23 -0500317 dentry->d_name.name, rc);
318 return rc;
Michael Halcrow391b52f2008-07-23 21:30:08 -0700319 }
Tyler Hicks778aeb42011-05-24 04:56:23 -0500320
Tyler Hicks3b06b3e2011-05-24 03:49:02 -0500321 crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
Tyler Hicks2aac0cf2009-03-20 02:23:57 -0500322 /* TODO: lock for crypt_stat comparison */
323 if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED))
Tyler Hicks778aeb42011-05-24 04:56:23 -0500324 ecryptfs_set_default_sizes(crypt_stat);
325
326 rc = ecryptfs_read_and_validate_header_region(inode);
327 ecryptfs_put_lower_file(inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700328 if (rc) {
Tyler Hicks778aeb42011-05-24 04:56:23 -0500329 rc = ecryptfs_read_and_validate_xattr_region(dentry, inode);
330 if (!rc)
331 crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
Michael Halcrow237fead2006-10-04 02:16:22 -0700332 }
Tyler Hicks778aeb42011-05-24 04:56:23 -0500333
334 /* Must return 0 to allow non-eCryptfs files to be looked up, too */
335 return 0;
336}
337
338/**
339 * ecryptfs_lookup_interpose - Dentry interposition for a lookup
340 */
341static int ecryptfs_lookup_interpose(struct dentry *dentry,
342 struct dentry *lower_dentry,
343 struct inode *dir_inode)
344{
345 struct inode *inode, *lower_inode = lower_dentry->d_inode;
346 struct ecryptfs_dentry_info *dentry_info;
347 struct vfsmount *lower_mnt;
348 int rc = 0;
349
Tyler Hicks778aeb42011-05-24 04:56:23 -0500350 dentry_info = kmem_cache_alloc(ecryptfs_dentry_info_cache, GFP_KERNEL);
Tyler Hicks778aeb42011-05-24 04:56:23 -0500351 if (!dentry_info) {
352 printk(KERN_ERR "%s: Out of memory whilst attempting "
353 "to allocate ecryptfs_dentry_info struct\n",
354 __func__);
355 dput(lower_dentry);
Tyler Hicks778aeb42011-05-24 04:56:23 -0500356 return -ENOMEM;
357 }
Al Viro0b1d9012012-07-20 12:09:19 +0400358
359 lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(dentry->d_parent));
360 fsstack_copy_attr_atime(dir_inode, lower_dentry->d_parent->d_inode);
Al Viro84d08fa2013-07-05 18:59:33 +0400361 BUG_ON(!d_count(lower_dentry));
Al Viro0b1d9012012-07-20 12:09:19 +0400362
363 ecryptfs_set_dentry_private(dentry, dentry_info);
Tyler Hicks778aeb42011-05-24 04:56:23 -0500364 ecryptfs_set_dentry_lower(dentry, lower_dentry);
365 ecryptfs_set_dentry_lower_mnt(dentry, lower_mnt);
366
367 if (!lower_dentry->d_inode) {
368 /* We want to add because we couldn't find in lower */
369 d_add(dentry, NULL);
370 return 0;
371 }
372 inode = __ecryptfs_get_inode(lower_inode, dir_inode->i_sb);
373 if (IS_ERR(inode)) {
374 printk(KERN_ERR "%s: Error interposing; rc = [%ld]\n",
375 __func__, PTR_ERR(inode));
376 return PTR_ERR(inode);
377 }
378 if (S_ISREG(inode->i_mode)) {
379 rc = ecryptfs_i_size_read(dentry, inode);
380 if (rc) {
381 make_bad_inode(inode);
382 return rc;
383 }
384 }
385
Tyler Hicks3b06b3e2011-05-24 03:49:02 -0500386 if (inode->i_state & I_NEW)
387 unlock_new_inode(inode);
Tyler Hicks778aeb42011-05-24 04:56:23 -0500388 d_add(dentry, inode);
389
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800390 return rc;
391}
392
393/**
394 * ecryptfs_lookup
395 * @ecryptfs_dir_inode: The eCryptfs directory inode
396 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
397 * @ecryptfs_nd: nameidata; may be NULL
398 *
399 * Find a file on disk. If the file does not exist, then we'll add it to the
400 * dentry cache and continue on to read it from the disk.
401 */
402static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
403 struct dentry *ecryptfs_dentry,
Al Viro00cd8dd2012-06-10 17:13:09 -0400404 unsigned int flags)
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800405{
406 char *encrypted_and_encoded_name = NULL;
Michael Halcrowa8f12862009-01-06 14:42:03 -0800407 size_t encrypted_and_encoded_name_size;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800408 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800409 struct dentry *lower_dir_dentry, *lower_dentry;
410 int rc = 0;
411
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800412 lower_dir_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry->d_parent);
Tyler Hicks8787c7a2011-02-17 18:51:24 -0600413 mutex_lock(&lower_dir_dentry->d_inode->i_mutex);
414 lower_dentry = lookup_one_len(ecryptfs_dentry->d_name.name,
415 lower_dir_dentry,
416 ecryptfs_dentry->d_name.len);
417 mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800418 if (IS_ERR(lower_dentry)) {
419 rc = PTR_ERR(lower_dentry);
Tyler Hicks8787c7a2011-02-17 18:51:24 -0600420 ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
Tyler Hicks9f376222010-03-25 11:16:56 -0500421 "[%d] on lower_dentry = [%s]\n", __func__, rc,
Al Virobc65a122012-07-20 12:03:41 +0400422 ecryptfs_dentry->d_name.name);
423 goto out;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800424 }
425 if (lower_dentry->d_inode)
Tyler Hicks5ccf9202011-05-24 02:16:51 -0500426 goto interpose;
Tyler Hicks2aac0cf2009-03-20 02:23:57 -0500427 mount_crypt_stat = &ecryptfs_superblock_to_private(
428 ecryptfs_dentry->d_sb)->mount_crypt_stat;
429 if (!(mount_crypt_stat
430 && (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)))
Tyler Hicks5ccf9202011-05-24 02:16:51 -0500431 goto interpose;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800432 dput(lower_dentry);
433 rc = ecryptfs_encrypt_and_encode_filename(
434 &encrypted_and_encoded_name, &encrypted_and_encoded_name_size,
Tyler Hicks2aac0cf2009-03-20 02:23:57 -0500435 NULL, mount_crypt_stat, ecryptfs_dentry->d_name.name,
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800436 ecryptfs_dentry->d_name.len);
437 if (rc) {
438 printk(KERN_ERR "%s: Error attempting to encrypt and encode "
439 "filename; rc = [%d]\n", __func__, rc);
Al Virobc65a122012-07-20 12:03:41 +0400440 goto out;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800441 }
Tyler Hicks8787c7a2011-02-17 18:51:24 -0600442 mutex_lock(&lower_dir_dentry->d_inode->i_mutex);
443 lower_dentry = lookup_one_len(encrypted_and_encoded_name,
444 lower_dir_dentry,
445 encrypted_and_encoded_name_size);
446 mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800447 if (IS_ERR(lower_dentry)) {
448 rc = PTR_ERR(lower_dentry);
Tyler Hicks8787c7a2011-02-17 18:51:24 -0600449 ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
Tyler Hicks9f376222010-03-25 11:16:56 -0500450 "[%d] on lower_dentry = [%s]\n", __func__, rc,
451 encrypted_and_encoded_name);
Al Virobc65a122012-07-20 12:03:41 +0400452 goto out;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800453 }
Tyler Hicks5ccf9202011-05-24 02:16:51 -0500454interpose:
455 rc = ecryptfs_lookup_interpose(ecryptfs_dentry, lower_dentry,
456 ecryptfs_dir_inode);
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800457out:
458 kfree(encrypted_and_encoded_name);
Michael Halcrow237fead2006-10-04 02:16:22 -0700459 return ERR_PTR(rc);
460}
461
462static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
463 struct dentry *new_dentry)
464{
465 struct dentry *lower_old_dentry;
466 struct dentry *lower_new_dentry;
467 struct dentry *lower_dir_dentry;
468 u64 file_size_save;
469 int rc;
470
471 file_size_save = i_size_read(old_dentry->d_inode);
472 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
473 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
474 dget(lower_old_dentry);
475 dget(lower_new_dentry);
476 lower_dir_dentry = lock_parent(lower_new_dentry);
477 rc = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode,
478 lower_new_dentry);
479 if (rc || !lower_new_dentry->d_inode)
480 goto out_lock;
Tyler Hicks5ccf9202011-05-24 02:16:51 -0500481 rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb);
Michael Halcrow237fead2006-10-04 02:16:22 -0700482 if (rc)
483 goto out_lock;
Tyler Hicks3a8380c2010-03-23 18:09:02 -0500484 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
485 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
Miklos Szeredibfe86842011-10-28 14:13:29 +0200486 set_nlink(old_dentry->d_inode,
487 ecryptfs_inode_to_lower(old_dentry->d_inode)->i_nlink);
Michael Halcrow237fead2006-10-04 02:16:22 -0700488 i_size_write(new_dentry->d_inode, file_size_save);
489out_lock:
490 unlock_dir(lower_dir_dentry);
491 dput(lower_new_dentry);
492 dput(lower_old_dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -0700493 return rc;
494}
495
496static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
497{
Tyler Hicks8bc2d3c2012-05-22 15:09:50 -0500498 return ecryptfs_do_unlink(dir, dentry, dentry->d_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700499}
500
501static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry,
502 const char *symname)
503{
504 int rc;
505 struct dentry *lower_dentry;
506 struct dentry *lower_dir_dentry;
Michael Halcrow237fead2006-10-04 02:16:22 -0700507 char *encoded_symname;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800508 size_t encoded_symlen;
509 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
Michael Halcrow237fead2006-10-04 02:16:22 -0700510
511 lower_dentry = ecryptfs_dentry_to_lower(dentry);
512 dget(lower_dentry);
513 lower_dir_dentry = lock_parent(lower_dentry);
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800514 mount_crypt_stat = &ecryptfs_superblock_to_private(
515 dir->i_sb)->mount_crypt_stat;
516 rc = ecryptfs_encrypt_and_encode_filename(&encoded_symname,
517 &encoded_symlen,
518 NULL,
519 mount_crypt_stat, symname,
520 strlen(symname));
521 if (rc)
Michael Halcrow237fead2006-10-04 02:16:22 -0700522 goto out_lock;
Michael Halcrow237fead2006-10-04 02:16:22 -0700523 rc = vfs_symlink(lower_dir_dentry->d_inode, lower_dentry,
Miklos Szeredidb2e7472008-06-24 16:50:16 +0200524 encoded_symname);
Michael Halcrow237fead2006-10-04 02:16:22 -0700525 kfree(encoded_symname);
526 if (rc || !lower_dentry->d_inode)
527 goto out_lock;
Tyler Hicks5ccf9202011-05-24 02:16:51 -0500528 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
Michael Halcrow237fead2006-10-04 02:16:22 -0700529 if (rc)
530 goto out_lock;
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -0800531 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
532 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700533out_lock:
534 unlock_dir(lower_dir_dentry);
535 dput(lower_dentry);
536 if (!dentry->d_inode)
537 d_drop(dentry);
538 return rc;
539}
540
Al Viro18bb1db2011-07-26 01:41:39 -0400541static int ecryptfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
Michael Halcrow237fead2006-10-04 02:16:22 -0700542{
543 int rc;
544 struct dentry *lower_dentry;
545 struct dentry *lower_dir_dentry;
546
547 lower_dentry = ecryptfs_dentry_to_lower(dentry);
548 lower_dir_dentry = lock_parent(lower_dentry);
549 rc = vfs_mkdir(lower_dir_dentry->d_inode, lower_dentry, mode);
550 if (rc || !lower_dentry->d_inode)
551 goto out;
Tyler Hicks5ccf9202011-05-24 02:16:51 -0500552 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
Michael Halcrow237fead2006-10-04 02:16:22 -0700553 if (rc)
554 goto out;
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -0800555 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
556 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
Miklos Szeredibfe86842011-10-28 14:13:29 +0200557 set_nlink(dir, lower_dir_dentry->d_inode->i_nlink);
Michael Halcrow237fead2006-10-04 02:16:22 -0700558out:
559 unlock_dir(lower_dir_dentry);
560 if (!dentry->d_inode)
561 d_drop(dentry);
562 return rc;
563}
564
565static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
566{
Michael Halcrow237fead2006-10-04 02:16:22 -0700567 struct dentry *lower_dentry;
Michael Halcrow237fead2006-10-04 02:16:22 -0700568 struct dentry *lower_dir_dentry;
Michael Halcrow45ec4aba2006-10-30 22:07:20 -0800569 int rc;
Michael Halcrow237fead2006-10-04 02:16:22 -0700570
571 lower_dentry = ecryptfs_dentry_to_lower(dentry);
Michael Halcrow45ec4aba2006-10-30 22:07:20 -0800572 dget(dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -0700573 lower_dir_dentry = lock_parent(lower_dentry);
Michael Halcrow45ec4aba2006-10-30 22:07:20 -0800574 dget(lower_dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -0700575 rc = vfs_rmdir(lower_dir_dentry->d_inode, lower_dentry);
Michael Halcrow45ec4aba2006-10-30 22:07:20 -0800576 dput(lower_dentry);
Tyler Hicks07850552011-04-29 16:26:27 -0500577 if (!rc && dentry->d_inode)
578 clear_nlink(dentry->d_inode);
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -0800579 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
Miklos Szeredibfe86842011-10-28 14:13:29 +0200580 set_nlink(dir, lower_dir_dentry->d_inode->i_nlink);
Michael Halcrow237fead2006-10-04 02:16:22 -0700581 unlock_dir(lower_dir_dentry);
582 if (!rc)
583 d_drop(dentry);
Michael Halcrow45ec4aba2006-10-30 22:07:20 -0800584 dput(dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -0700585 return rc;
586}
587
588static int
Al Viro1a67aaf2011-07-26 01:52:52 -0400589ecryptfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
Michael Halcrow237fead2006-10-04 02:16:22 -0700590{
591 int rc;
592 struct dentry *lower_dentry;
593 struct dentry *lower_dir_dentry;
594
595 lower_dentry = ecryptfs_dentry_to_lower(dentry);
596 lower_dir_dentry = lock_parent(lower_dentry);
597 rc = vfs_mknod(lower_dir_dentry->d_inode, lower_dentry, mode, dev);
598 if (rc || !lower_dentry->d_inode)
599 goto out;
Tyler Hicks5ccf9202011-05-24 02:16:51 -0500600 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
Michael Halcrow237fead2006-10-04 02:16:22 -0700601 if (rc)
602 goto out;
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -0800603 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
604 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700605out:
606 unlock_dir(lower_dir_dentry);
607 if (!dentry->d_inode)
608 d_drop(dentry);
609 return rc;
610}
611
612static int
613ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
614 struct inode *new_dir, struct dentry *new_dentry)
615{
616 int rc;
617 struct dentry *lower_old_dentry;
618 struct dentry *lower_new_dentry;
619 struct dentry *lower_old_dir_dentry;
620 struct dentry *lower_new_dir_dentry;
Erez Zadok0d132f72009-12-05 21:17:09 -0500621 struct dentry *trap = NULL;
Tyler Hicks8335eaf2012-09-13 12:00:56 -0700622 struct inode *target_inode;
Michael Halcrow237fead2006-10-04 02:16:22 -0700623
624 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
625 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
626 dget(lower_old_dentry);
627 dget(lower_new_dentry);
628 lower_old_dir_dentry = dget_parent(lower_old_dentry);
629 lower_new_dir_dentry = dget_parent(lower_new_dentry);
Tyler Hicks8335eaf2012-09-13 12:00:56 -0700630 target_inode = new_dentry->d_inode;
Erez Zadok0d132f72009-12-05 21:17:09 -0500631 trap = lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
632 /* source should not be ancestor of target */
633 if (trap == lower_old_dentry) {
634 rc = -EINVAL;
635 goto out_lock;
636 }
637 /* target should not be ancestor of source */
638 if (trap == lower_new_dentry) {
639 rc = -ENOTEMPTY;
640 goto out_lock;
641 }
Michael Halcrow237fead2006-10-04 02:16:22 -0700642 rc = vfs_rename(lower_old_dir_dentry->d_inode, lower_old_dentry,
643 lower_new_dir_dentry->d_inode, lower_new_dentry);
644 if (rc)
645 goto out_lock;
Tyler Hicks8335eaf2012-09-13 12:00:56 -0700646 if (target_inode)
647 fsstack_copy_attr_all(target_inode,
648 ecryptfs_inode_to_lower(target_inode));
Erez Zadok9afa2fb2009-12-02 19:51:54 -0500649 fsstack_copy_attr_all(new_dir, lower_new_dir_dentry->d_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700650 if (new_dir != old_dir)
Erez Zadok9afa2fb2009-12-02 19:51:54 -0500651 fsstack_copy_attr_all(old_dir, lower_old_dir_dentry->d_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700652out_lock:
653 unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
Tyler Hicksdd55c8982011-04-12 11:23:09 -0500654 dput(lower_new_dir_dentry);
655 dput(lower_old_dir_dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -0700656 dput(lower_new_dentry);
657 dput(lower_old_dentry);
658 return rc;
659}
660
Tyler Hicks3a60a162010-03-22 00:41:35 -0500661static int ecryptfs_readlink_lower(struct dentry *dentry, char **buf,
662 size_t *bufsiz)
Michael Halcrow237fead2006-10-04 02:16:22 -0700663{
Tyler Hicks3a60a162010-03-22 00:41:35 -0500664 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -0700665 char *lower_buf;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800666 mm_segment_t old_fs;
667 int rc;
Michael Halcrow237fead2006-10-04 02:16:22 -0700668
Al Viro408bd622012-05-03 09:34:20 -0400669 lower_buf = kmalloc(PATH_MAX, GFP_KERNEL);
Tyler Hicks3a60a162010-03-22 00:41:35 -0500670 if (!lower_buf) {
Michael Halcrow237fead2006-10-04 02:16:22 -0700671 rc = -ENOMEM;
672 goto out;
673 }
674 old_fs = get_fs();
675 set_fs(get_ds());
Michael Halcrow237fead2006-10-04 02:16:22 -0700676 rc = lower_dentry->d_inode->i_op->readlink(lower_dentry,
677 (char __user *)lower_buf,
Al Viro408bd622012-05-03 09:34:20 -0400678 PATH_MAX);
Michael Halcrow237fead2006-10-04 02:16:22 -0700679 set_fs(old_fs);
Tyler Hicks3a60a162010-03-22 00:41:35 -0500680 if (rc < 0)
681 goto out;
Al Viro0747fdb2013-06-16 20:05:38 +0400682 rc = ecryptfs_decode_and_decrypt_filename(buf, bufsiz, dentry->d_sb,
Al Viro408bd622012-05-03 09:34:20 -0400683 lower_buf, rc);
Tyler Hicks3a60a162010-03-22 00:41:35 -0500684out:
Michael Halcrow237fead2006-10-04 02:16:22 -0700685 kfree(lower_buf);
Tyler Hicks3a60a162010-03-22 00:41:35 -0500686 return rc;
687}
688
Michael Halcrow237fead2006-10-04 02:16:22 -0700689static void *ecryptfs_follow_link(struct dentry *dentry, struct nameidata *nd)
690{
691 char *buf;
Al Viro408bd622012-05-03 09:34:20 -0400692 size_t len = PATH_MAX;
693 int rc;
Michael Halcrow237fead2006-10-04 02:16:22 -0700694
Al Viro408bd622012-05-03 09:34:20 -0400695 rc = ecryptfs_readlink_lower(dentry, &buf, &len);
696 if (rc)
Michael Halcrow237fead2006-10-04 02:16:22 -0700697 goto out;
Al Viro408bd622012-05-03 09:34:20 -0400698 fsstack_copy_attr_atime(dentry->d_inode,
699 ecryptfs_dentry_to_lower(dentry)->d_inode);
700 buf[len] = '\0';
Michael Halcrow237fead2006-10-04 02:16:22 -0700701out:
OGAWA Hirofumi806892e2010-01-12 03:36:14 +0900702 nd_set_link(nd, buf);
703 return NULL;
Michael Halcrow237fead2006-10-04 02:16:22 -0700704}
705
706static void
707ecryptfs_put_link(struct dentry *dentry, struct nameidata *nd, void *ptr)
708{
OGAWA Hirofumi806892e2010-01-12 03:36:14 +0900709 char *buf = nd_get_link(nd);
710 if (!IS_ERR(buf)) {
711 /* Free the char* */
712 kfree(buf);
713 }
Michael Halcrow237fead2006-10-04 02:16:22 -0700714}
715
716/**
717 * upper_size_to_lower_size
718 * @crypt_stat: Crypt_stat associated with file
719 * @upper_size: Size of the upper file
720 *
Michael Halcrowcc11bef2008-02-06 01:38:32 -0800721 * Calculate the required size of the lower file based on the
Michael Halcrow237fead2006-10-04 02:16:22 -0700722 * specified size of the upper file. This calculation is based on the
723 * number of headers in the underlying file and the extent size.
724 *
725 * Returns Calculated size of the lower file.
726 */
727static loff_t
728upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
729 loff_t upper_size)
730{
731 loff_t lower_size;
732
Tyler Hicks157f1072010-02-11 07:10:38 -0600733 lower_size = ecryptfs_lower_header_size(crypt_stat);
Michael Halcrow237fead2006-10-04 02:16:22 -0700734 if (upper_size != 0) {
735 loff_t num_extents;
736
737 num_extents = upper_size >> crypt_stat->extent_shift;
738 if (upper_size & ~crypt_stat->extent_mask)
739 num_extents++;
740 lower_size += (num_extents * crypt_stat->extent_size);
741 }
742 return lower_size;
743}
744
745/**
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500746 * truncate_upper
Michael Halcrow237fead2006-10-04 02:16:22 -0700747 * @dentry: The ecryptfs layer dentry
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500748 * @ia: Address of the ecryptfs inode's attributes
749 * @lower_ia: Address of the lower inode's attributes
Michael Halcrow237fead2006-10-04 02:16:22 -0700750 *
751 * Function to handle truncations modifying the size of the file. Note
752 * that the file sizes are interpolated. When expanding, we are simply
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500753 * writing strings of 0's out. When truncating, we truncate the upper
754 * inode and update the lower_ia according to the page index
755 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
756 * the caller must use lower_ia in a call to notify_change() to perform
757 * the truncation of the lower inode.
Michael Halcrow237fead2006-10-04 02:16:22 -0700758 *
759 * Returns zero on success; non-zero otherwise
760 */
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500761static int truncate_upper(struct dentry *dentry, struct iattr *ia,
762 struct iattr *lower_ia)
Michael Halcrow237fead2006-10-04 02:16:22 -0700763{
764 int rc = 0;
765 struct inode *inode = dentry->d_inode;
Michael Halcrow237fead2006-10-04 02:16:22 -0700766 struct ecryptfs_crypt_stat *crypt_stat;
767 loff_t i_size = i_size_read(inode);
768 loff_t lower_size_before_truncate;
769 loff_t lower_size_after_truncate;
770
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500771 if (unlikely((ia->ia_size == i_size))) {
772 lower_ia->ia_valid &= ~ATTR_SIZE;
Tyler Hicks332ab162011-04-14 15:35:11 -0500773 return 0;
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500774 }
Tyler Hicks3b06b3e2011-05-24 03:49:02 -0500775 rc = ecryptfs_get_lower_file(dentry, inode);
Tyler Hicks332ab162011-04-14 15:35:11 -0500776 if (rc)
777 return rc;
Michael Halcrow237fead2006-10-04 02:16:22 -0700778 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
Michael Halcrow237fead2006-10-04 02:16:22 -0700779 /* Switch on growing or shrinking file */
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500780 if (ia->ia_size > i_size) {
Michael Halcrow2ed92552007-10-16 01:28:10 -0700781 char zero[] = { 0x00 };
Michael Halcrow240e2df2007-06-27 14:09:44 -0700782
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500783 lower_ia->ia_valid &= ~ATTR_SIZE;
Michael Halcrow2ed92552007-10-16 01:28:10 -0700784 /* Write a single 0 at the last position of the file;
785 * this triggers code that will fill in 0's throughout
786 * the intermediate portion of the previous end of the
787 * file and the new and of the file */
Al Viro48c1e442010-05-21 11:09:58 -0400788 rc = ecryptfs_write(inode, zero,
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500789 (ia->ia_size - 1), 1);
790 } else { /* ia->ia_size < i_size_read(inode) */
791 /* We're chopping off all the pages down to the page
792 * in which ia->ia_size is located. Fill in the end of
793 * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
Michael Halcrow2ed92552007-10-16 01:28:10 -0700794 * PAGE_CACHE_SIZE with zeros. */
795 size_t num_zeros = (PAGE_CACHE_SIZE
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500796 - (ia->ia_size & ~PAGE_CACHE_MASK));
Michael Halcrow2ed92552007-10-16 01:28:10 -0700797
Tyler Hicks13a791b2009-04-13 15:29:27 -0500798 if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
Christoph Hellwig2c27c652010-06-04 11:30:04 +0200799 truncate_setsize(inode, ia->ia_size);
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500800 lower_ia->ia_size = ia->ia_size;
801 lower_ia->ia_valid |= ATTR_SIZE;
Al Viro48c1e442010-05-21 11:09:58 -0400802 goto out;
Tyler Hicks13a791b2009-04-13 15:29:27 -0500803 }
Michael Halcrow2ed92552007-10-16 01:28:10 -0700804 if (num_zeros) {
805 char *zeros_virt;
806
807 zeros_virt = kzalloc(num_zeros, GFP_KERNEL);
808 if (!zeros_virt) {
809 rc = -ENOMEM;
Al Viro48c1e442010-05-21 11:09:58 -0400810 goto out;
Michael Halcrow2ed92552007-10-16 01:28:10 -0700811 }
Al Viro48c1e442010-05-21 11:09:58 -0400812 rc = ecryptfs_write(inode, zeros_virt,
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500813 ia->ia_size, num_zeros);
Michael Halcrow2ed92552007-10-16 01:28:10 -0700814 kfree(zeros_virt);
Michael Halcrow5dda6992007-10-16 01:28:06 -0700815 if (rc) {
Michael Halcrow240e2df2007-06-27 14:09:44 -0700816 printk(KERN_ERR "Error attempting to zero out "
817 "the remainder of the end page on "
818 "reducing truncate; rc = [%d]\n", rc);
Al Viro48c1e442010-05-21 11:09:58 -0400819 goto out;
Michael Halcrow240e2df2007-06-27 14:09:44 -0700820 }
821 }
Christoph Hellwig2c27c652010-06-04 11:30:04 +0200822 truncate_setsize(inode, ia->ia_size);
Michael Halcrow0216f7f2007-10-16 01:28:08 -0700823 rc = ecryptfs_write_inode_size_to_metadata(inode);
Michael Halcrowdd2a3b72007-02-12 00:53:46 -0800824 if (rc) {
825 printk(KERN_ERR "Problem with "
826 "ecryptfs_write_inode_size_to_metadata; "
827 "rc = [%d]\n", rc);
Al Viro48c1e442010-05-21 11:09:58 -0400828 goto out;
Michael Halcrowdd2a3b72007-02-12 00:53:46 -0800829 }
Michael Halcrow237fead2006-10-04 02:16:22 -0700830 /* We are reducing the size of the ecryptfs file, and need to
831 * know if we need to reduce the size of the lower file. */
832 lower_size_before_truncate =
833 upper_size_to_lower_size(crypt_stat, i_size);
834 lower_size_after_truncate =
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500835 upper_size_to_lower_size(crypt_stat, ia->ia_size);
836 if (lower_size_after_truncate < lower_size_before_truncate) {
837 lower_ia->ia_size = lower_size_after_truncate;
838 lower_ia->ia_valid |= ATTR_SIZE;
839 } else
840 lower_ia->ia_valid &= ~ATTR_SIZE;
Michael Halcrow237fead2006-10-04 02:16:22 -0700841 }
Michael Halcrow237fead2006-10-04 02:16:22 -0700842out:
Tyler Hicks332ab162011-04-14 15:35:11 -0500843 ecryptfs_put_lower_file(inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700844 return rc;
845}
846
Tyler Hicksa261a032012-01-19 20:33:44 -0600847static int ecryptfs_inode_newsize_ok(struct inode *inode, loff_t offset)
848{
849 struct ecryptfs_crypt_stat *crypt_stat;
850 loff_t lower_oldsize, lower_newsize;
851
852 crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
853 lower_oldsize = upper_size_to_lower_size(crypt_stat,
854 i_size_read(inode));
855 lower_newsize = upper_size_to_lower_size(crypt_stat, offset);
856 if (lower_newsize > lower_oldsize) {
857 /*
858 * The eCryptfs inode and the new *lower* size are mixed here
859 * because we may not have the lower i_mutex held and/or it may
860 * not be appropriate to call inode_newsize_ok() with inodes
861 * from other filesystems.
862 */
863 return inode_newsize_ok(inode, lower_newsize);
864 }
865
866 return 0;
867}
868
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500869/**
870 * ecryptfs_truncate
871 * @dentry: The ecryptfs layer dentry
872 * @new_length: The length to expand the file to
873 *
874 * Simple function that handles the truncation of an eCryptfs inode and
875 * its corresponding lower inode.
876 *
877 * Returns zero on success; non-zero otherwise
878 */
879int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
880{
881 struct iattr ia = { .ia_valid = ATTR_SIZE, .ia_size = new_length };
882 struct iattr lower_ia = { .ia_valid = 0 };
883 int rc;
884
Tyler Hicksa261a032012-01-19 20:33:44 -0600885 rc = ecryptfs_inode_newsize_ok(dentry->d_inode, new_length);
886 if (rc)
887 return rc;
888
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500889 rc = truncate_upper(dentry, &ia, &lower_ia);
890 if (!rc && lower_ia.ia_valid & ATTR_SIZE) {
891 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
892
893 mutex_lock(&lower_dentry->d_inode->i_mutex);
894 rc = notify_change(lower_dentry, &lower_ia);
895 mutex_unlock(&lower_dentry->d_inode->i_mutex);
896 }
897 return rc;
898}
899
Michael Halcrow237fead2006-10-04 02:16:22 -0700900static int
Al Viro10556cb2011-06-20 19:28:19 -0400901ecryptfs_permission(struct inode *inode, int mask)
Michael Halcrow237fead2006-10-04 02:16:22 -0700902{
Al Virof419a2e2008-07-22 00:07:17 -0400903 return inode_permission(ecryptfs_inode_to_lower(inode), mask);
Michael Halcrow237fead2006-10-04 02:16:22 -0700904}
905
906/**
907 * ecryptfs_setattr
908 * @dentry: dentry handle to the inode to modify
909 * @ia: Structure with flags of what to change and values
910 *
911 * Updates the metadata of an inode. If the update is to the size
912 * i.e. truncation, then ecryptfs_truncate will handle the size modification
913 * of both the ecryptfs inode and the lower inode.
914 *
915 * All other metadata changes will be passed right to the lower filesystem,
916 * and we will just update our inode to look like the lower.
917 */
918static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
919{
920 int rc = 0;
921 struct dentry *lower_dentry;
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500922 struct iattr lower_ia;
Michael Halcrow237fead2006-10-04 02:16:22 -0700923 struct inode *inode;
924 struct inode *lower_inode;
925 struct ecryptfs_crypt_stat *crypt_stat;
926
927 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
Michael Halcrowe10f2812007-06-27 14:09:44 -0700928 if (!(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED))
929 ecryptfs_init_crypt_stat(crypt_stat);
Michael Halcrow237fead2006-10-04 02:16:22 -0700930 inode = dentry->d_inode;
931 lower_inode = ecryptfs_inode_to_lower(inode);
Michael Halcrowe10f2812007-06-27 14:09:44 -0700932 lower_dentry = ecryptfs_dentry_to_lower(dentry);
933 mutex_lock(&crypt_stat->cs_mutex);
934 if (S_ISDIR(dentry->d_inode->i_mode))
935 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
Michael Halcrow64ee4802007-07-19 01:47:54 -0700936 else if (S_ISREG(dentry->d_inode->i_mode)
937 && (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
938 || !(crypt_stat->flags & ECRYPTFS_KEY_VALID))) {
Michael Halcrowe10f2812007-06-27 14:09:44 -0700939 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
Michael Halcrowe10f2812007-06-27 14:09:44 -0700940
Michael Halcrowe10f2812007-06-27 14:09:44 -0700941 mount_crypt_stat = &ecryptfs_superblock_to_private(
942 dentry->d_sb)->mount_crypt_stat;
Tyler Hicks3b06b3e2011-05-24 03:49:02 -0500943 rc = ecryptfs_get_lower_file(dentry, inode);
Tyler Hicks332ab162011-04-14 15:35:11 -0500944 if (rc) {
945 mutex_unlock(&crypt_stat->cs_mutex);
946 goto out;
947 }
Michael Halcrowd7cdc5f2007-10-16 01:28:10 -0700948 rc = ecryptfs_read_metadata(dentry);
Tyler Hicks332ab162011-04-14 15:35:11 -0500949 ecryptfs_put_lower_file(inode);
Michael Halcrow5dda6992007-10-16 01:28:06 -0700950 if (rc) {
Michael Halcrowe10f2812007-06-27 14:09:44 -0700951 if (!(mount_crypt_stat->flags
952 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
953 rc = -EIO;
Michael Halcrow25bd8172008-02-06 01:38:35 -0800954 printk(KERN_WARNING "Either the lower file "
Michael Halcrowe10f2812007-06-27 14:09:44 -0700955 "is not in a valid eCryptfs format, "
Michael Halcrow25bd8172008-02-06 01:38:35 -0800956 "or the key could not be retrieved. "
957 "Plaintext passthrough mode is not "
Michael Halcrowe10f2812007-06-27 14:09:44 -0700958 "enabled; returning -EIO\n");
Michael Halcrowe10f2812007-06-27 14:09:44 -0700959 mutex_unlock(&crypt_stat->cs_mutex);
Michael Halcrowe10f2812007-06-27 14:09:44 -0700960 goto out;
961 }
962 rc = 0;
Tyler Hicks3aeb86e2011-03-15 14:54:00 -0500963 crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED
964 | ECRYPTFS_ENCRYPTED);
Michael Halcrowe10f2812007-06-27 14:09:44 -0700965 }
Michael Halcrowe10f2812007-06-27 14:09:44 -0700966 }
967 mutex_unlock(&crypt_stat->cs_mutex);
Tyler Hicksa261a032012-01-19 20:33:44 -0600968
969 rc = inode_change_ok(inode, ia);
970 if (rc)
971 goto out;
972 if (ia->ia_valid & ATTR_SIZE) {
973 rc = ecryptfs_inode_newsize_ok(inode, ia->ia_size);
974 if (rc)
975 goto out;
976 }
977
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500978 memcpy(&lower_ia, ia, sizeof(lower_ia));
979 if (ia->ia_valid & ATTR_FILE)
980 lower_ia.ia_file = ecryptfs_file_to_lower(ia->ia_file);
Michael Halcrow237fead2006-10-04 02:16:22 -0700981 if (ia->ia_valid & ATTR_SIZE) {
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500982 rc = truncate_upper(dentry, ia, &lower_ia);
Michael Halcrow237fead2006-10-04 02:16:22 -0700983 if (rc < 0)
984 goto out;
985 }
Jeff Layton1ac564e2007-10-18 03:05:17 -0700986
987 /*
988 * mode change is for clearing setuid/setgid bits. Allow lower fs
989 * to interpret this in its own way.
990 */
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500991 if (lower_ia.ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
992 lower_ia.ia_valid &= ~ATTR_MODE;
Jeff Layton1ac564e2007-10-18 03:05:17 -0700993
Miklos Szeredi9c3580a2008-04-29 00:59:48 -0700994 mutex_lock(&lower_dentry->d_inode->i_mutex);
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500995 rc = notify_change(lower_dentry, &lower_ia);
Miklos Szeredi9c3580a2008-04-29 00:59:48 -0700996 mutex_unlock(&lower_dentry->d_inode->i_mutex);
Michael Halcrow237fead2006-10-04 02:16:22 -0700997out:
Erez Zadok9afa2fb2009-12-02 19:51:54 -0500998 fsstack_copy_attr_all(inode, lower_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700999 return rc;
1000}
1001
Tyler Hicks111d61a2013-01-17 12:19:35 -08001002static int ecryptfs_getattr_link(struct vfsmount *mnt, struct dentry *dentry,
1003 struct kstat *stat)
Tyler Hicks3a60a162010-03-22 00:41:35 -05001004{
1005 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
1006 int rc = 0;
1007
1008 mount_crypt_stat = &ecryptfs_superblock_to_private(
1009 dentry->d_sb)->mount_crypt_stat;
1010 generic_fillattr(dentry->d_inode, stat);
1011 if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) {
1012 char *target;
1013 size_t targetsiz;
1014
1015 rc = ecryptfs_readlink_lower(dentry, &target, &targetsiz);
1016 if (!rc) {
1017 kfree(target);
1018 stat->size = targetsiz;
1019 }
1020 }
1021 return rc;
1022}
1023
Tyler Hicks111d61a2013-01-17 12:19:35 -08001024static int ecryptfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
1025 struct kstat *stat)
Tyler Hicksf8f484d2009-11-04 02:48:01 -06001026{
1027 struct kstat lower_stat;
1028 int rc;
1029
Al Viro3dadecc2013-01-24 02:18:08 -05001030 rc = vfs_getattr(ecryptfs_dentry_to_lower_path(dentry), &lower_stat);
Tyler Hicksf8f484d2009-11-04 02:48:01 -06001031 if (!rc) {
Tyler Hicks55f9cf62011-01-11 12:43:42 -06001032 fsstack_copy_attr_all(dentry->d_inode,
1033 ecryptfs_inode_to_lower(dentry->d_inode));
Tyler Hicksf8f484d2009-11-04 02:48:01 -06001034 generic_fillattr(dentry->d_inode, stat);
1035 stat->blocks = lower_stat.blocks;
1036 }
1037 return rc;
1038}
1039
Michael Halcrowdd2a3b72007-02-12 00:53:46 -08001040int
Michael Halcrow237fead2006-10-04 02:16:22 -07001041ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value,
1042 size_t size, int flags)
1043{
1044 int rc = 0;
1045 struct dentry *lower_dentry;
1046
1047 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1048 if (!lower_dentry->d_inode->i_op->setxattr) {
Christian Pulvermachercfce08c2010-03-23 11:51:38 -05001049 rc = -EOPNOTSUPP;
Michael Halcrow237fead2006-10-04 02:16:22 -07001050 goto out;
1051 }
Roberto Sassu48b512e2010-10-05 18:53:45 +02001052
1053 rc = vfs_setxattr(lower_dentry, name, value, size, flags);
Tyler Hicks545d6802012-02-07 17:55:40 -06001054 if (!rc)
1055 fsstack_copy_attr_all(dentry->d_inode, lower_dentry->d_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -07001056out:
1057 return rc;
1058}
1059
Michael Halcrowdd2a3b72007-02-12 00:53:46 -08001060ssize_t
Michael Halcrowd7cdc5f2007-10-16 01:28:10 -07001061ecryptfs_getxattr_lower(struct dentry *lower_dentry, const char *name,
1062 void *value, size_t size)
1063{
1064 int rc = 0;
1065
1066 if (!lower_dentry->d_inode->i_op->getxattr) {
Christian Pulvermachercfce08c2010-03-23 11:51:38 -05001067 rc = -EOPNOTSUPP;
Michael Halcrowd7cdc5f2007-10-16 01:28:10 -07001068 goto out;
1069 }
1070 mutex_lock(&lower_dentry->d_inode->i_mutex);
1071 rc = lower_dentry->d_inode->i_op->getxattr(lower_dentry, name, value,
1072 size);
1073 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1074out:
1075 return rc;
1076}
1077
Adrian Bunk7896b632008-02-06 01:38:32 -08001078static ssize_t
Michael Halcrow237fead2006-10-04 02:16:22 -07001079ecryptfs_getxattr(struct dentry *dentry, const char *name, void *value,
1080 size_t size)
1081{
Michael Halcrow2ed92552007-10-16 01:28:10 -07001082 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry), name,
1083 value, size);
Michael Halcrow237fead2006-10-04 02:16:22 -07001084}
1085
1086static ssize_t
1087ecryptfs_listxattr(struct dentry *dentry, char *list, size_t size)
1088{
1089 int rc = 0;
1090 struct dentry *lower_dentry;
1091
1092 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1093 if (!lower_dentry->d_inode->i_op->listxattr) {
Christian Pulvermachercfce08c2010-03-23 11:51:38 -05001094 rc = -EOPNOTSUPP;
Michael Halcrow237fead2006-10-04 02:16:22 -07001095 goto out;
1096 }
1097 mutex_lock(&lower_dentry->d_inode->i_mutex);
1098 rc = lower_dentry->d_inode->i_op->listxattr(lower_dentry, list, size);
1099 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1100out:
1101 return rc;
1102}
1103
1104static int ecryptfs_removexattr(struct dentry *dentry, const char *name)
1105{
1106 int rc = 0;
1107 struct dentry *lower_dentry;
1108
1109 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1110 if (!lower_dentry->d_inode->i_op->removexattr) {
Christian Pulvermachercfce08c2010-03-23 11:51:38 -05001111 rc = -EOPNOTSUPP;
Michael Halcrow237fead2006-10-04 02:16:22 -07001112 goto out;
1113 }
1114 mutex_lock(&lower_dentry->d_inode->i_mutex);
1115 rc = lower_dentry->d_inode->i_op->removexattr(lower_dentry, name);
1116 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1117out:
1118 return rc;
1119}
1120
Arjan van de Ven754661f2007-02-12 00:55:38 -08001121const struct inode_operations ecryptfs_symlink_iops = {
Al Viro408bd622012-05-03 09:34:20 -04001122 .readlink = generic_readlink,
Michael Halcrow237fead2006-10-04 02:16:22 -07001123 .follow_link = ecryptfs_follow_link,
1124 .put_link = ecryptfs_put_link,
1125 .permission = ecryptfs_permission,
1126 .setattr = ecryptfs_setattr,
Tyler Hicks3a60a162010-03-22 00:41:35 -05001127 .getattr = ecryptfs_getattr_link,
Michael Halcrow237fead2006-10-04 02:16:22 -07001128 .setxattr = ecryptfs_setxattr,
1129 .getxattr = ecryptfs_getxattr,
1130 .listxattr = ecryptfs_listxattr,
1131 .removexattr = ecryptfs_removexattr
1132};
1133
Arjan van de Ven754661f2007-02-12 00:55:38 -08001134const struct inode_operations ecryptfs_dir_iops = {
Michael Halcrow237fead2006-10-04 02:16:22 -07001135 .create = ecryptfs_create,
1136 .lookup = ecryptfs_lookup,
1137 .link = ecryptfs_link,
1138 .unlink = ecryptfs_unlink,
1139 .symlink = ecryptfs_symlink,
1140 .mkdir = ecryptfs_mkdir,
1141 .rmdir = ecryptfs_rmdir,
1142 .mknod = ecryptfs_mknod,
1143 .rename = ecryptfs_rename,
1144 .permission = ecryptfs_permission,
1145 .setattr = ecryptfs_setattr,
1146 .setxattr = ecryptfs_setxattr,
1147 .getxattr = ecryptfs_getxattr,
1148 .listxattr = ecryptfs_listxattr,
1149 .removexattr = ecryptfs_removexattr
1150};
1151
Arjan van de Ven754661f2007-02-12 00:55:38 -08001152const struct inode_operations ecryptfs_main_iops = {
Michael Halcrow237fead2006-10-04 02:16:22 -07001153 .permission = ecryptfs_permission,
1154 .setattr = ecryptfs_setattr,
Tyler Hicksf8f484d2009-11-04 02:48:01 -06001155 .getattr = ecryptfs_getattr,
Michael Halcrow237fead2006-10-04 02:16:22 -07001156 .setxattr = ecryptfs_setxattr,
1157 .getxattr = ecryptfs_getxattr,
1158 .listxattr = ecryptfs_listxattr,
1159 .removexattr = ecryptfs_removexattr
1160};