blob: b08b5187f6622cb6c7934d6dba9fcdfdbb0aefb6 [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{
Himangi Saraogic4cf3ba2014-06-27 01:11:59 +053056 return ecryptfs_inode_to_lower(inode) == lower_inode;
Tyler Hicksc4f79072011-05-23 21:18:20 -050057}
58
Tyler Hicks5ccf9202011-05-24 02:16:51 -050059static int ecryptfs_inode_set(struct inode *inode, void *opaque)
Tyler Hicksc4f79072011-05-23 21:18:20 -050060{
Tyler Hicks5ccf9202011-05-24 02:16:51 -050061 struct inode *lower_inode = opaque;
62
63 ecryptfs_set_inode_lower(inode, lower_inode);
64 fsstack_copy_attr_all(inode, lower_inode);
65 /* i_size will be overwritten for encrypted regular files */
66 fsstack_copy_inode_size(inode, lower_inode);
67 inode->i_ino = lower_inode->i_ino;
Tyler Hicksc4f79072011-05-23 21:18:20 -050068 inode->i_version++;
Tyler Hicksc4f79072011-05-23 21:18:20 -050069 inode->i_mapping->a_ops = &ecryptfs_aops;
Tyler Hicks5ccf9202011-05-24 02:16:51 -050070
71 if (S_ISLNK(inode->i_mode))
72 inode->i_op = &ecryptfs_symlink_iops;
73 else if (S_ISDIR(inode->i_mode))
74 inode->i_op = &ecryptfs_dir_iops;
75 else
76 inode->i_op = &ecryptfs_main_iops;
77
78 if (S_ISDIR(inode->i_mode))
79 inode->i_fop = &ecryptfs_dir_fops;
80 else if (special_file(inode->i_mode))
81 init_special_inode(inode, inode->i_mode, inode->i_rdev);
82 else
83 inode->i_fop = &ecryptfs_main_fops;
84
Tyler Hicksc4f79072011-05-23 21:18:20 -050085 return 0;
86}
87
Tyler Hicks5ccf9202011-05-24 02:16:51 -050088static struct inode *__ecryptfs_get_inode(struct inode *lower_inode,
89 struct super_block *sb)
90{
91 struct inode *inode;
92
93 if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb))
94 return ERR_PTR(-EXDEV);
95 if (!igrab(lower_inode))
96 return ERR_PTR(-ESTALE);
97 inode = iget5_locked(sb, (unsigned long)lower_inode,
98 ecryptfs_inode_test, ecryptfs_inode_set,
99 lower_inode);
100 if (!inode) {
101 iput(lower_inode);
102 return ERR_PTR(-EACCES);
103 }
104 if (!(inode->i_state & I_NEW))
105 iput(lower_inode);
106
107 return inode;
108}
109
Tyler Hicksc4f79072011-05-23 21:18:20 -0500110struct inode *ecryptfs_get_inode(struct inode *lower_inode,
111 struct super_block *sb)
112{
Tyler Hicks5ccf9202011-05-24 02:16:51 -0500113 struct inode *inode = __ecryptfs_get_inode(lower_inode, sb);
Tyler Hicksc4f79072011-05-23 21:18:20 -0500114
Tyler Hicks5ccf9202011-05-24 02:16:51 -0500115 if (!IS_ERR(inode) && (inode->i_state & I_NEW))
Tyler Hicksc4f79072011-05-23 21:18:20 -0500116 unlock_new_inode(inode);
Tyler Hicks5ccf9202011-05-24 02:16:51 -0500117
Tyler Hicksc4f79072011-05-23 21:18:20 -0500118 return inode;
Tyler Hicksc4f79072011-05-23 21:18:20 -0500119}
120
Tyler Hicksc4f79072011-05-23 21:18:20 -0500121/**
122 * ecryptfs_interpose
123 * @lower_dentry: Existing dentry in the lower filesystem
124 * @dentry: ecryptfs' dentry
125 * @sb: ecryptfs's super_block
Tyler Hicksc4f79072011-05-23 21:18:20 -0500126 *
127 * Interposes upper and lower dentries.
128 *
129 * Returns zero on success; non-zero otherwise
130 */
131static int ecryptfs_interpose(struct dentry *lower_dentry,
Tyler Hicks5ccf9202011-05-24 02:16:51 -0500132 struct dentry *dentry, struct super_block *sb)
Tyler Hicksc4f79072011-05-23 21:18:20 -0500133{
Tyler Hicks5ccf9202011-05-24 02:16:51 -0500134 struct inode *inode = ecryptfs_get_inode(lower_dentry->d_inode, sb);
135
Tyler Hicksc4f79072011-05-23 21:18:20 -0500136 if (IS_ERR(inode))
137 return PTR_ERR(inode);
Tyler Hicks5ccf9202011-05-24 02:16:51 -0500138 d_instantiate(dentry, inode);
139
Tyler Hicksc4f79072011-05-23 21:18:20 -0500140 return 0;
141}
142
Tyler Hicks8bc2d3c2012-05-22 15:09:50 -0500143static int ecryptfs_do_unlink(struct inode *dir, struct dentry *dentry,
144 struct inode *inode)
145{
146 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
147 struct inode *lower_dir_inode = ecryptfs_inode_to_lower(dir);
148 struct dentry *lower_dir_dentry;
149 int rc;
150
151 dget(lower_dentry);
152 lower_dir_dentry = lock_parent(lower_dentry);
J. Bruce Fieldsb21996e2011-09-20 09:14:34 -0400153 rc = vfs_unlink(lower_dir_inode, lower_dentry, NULL);
Tyler Hicks8bc2d3c2012-05-22 15:09:50 -0500154 if (rc) {
155 printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc);
156 goto out_unlock;
157 }
158 fsstack_copy_attr_times(dir, lower_dir_inode);
159 set_nlink(inode, ecryptfs_inode_to_lower(inode)->i_nlink);
160 inode->i_ctime = dir->i_ctime;
161 d_drop(dentry);
162out_unlock:
163 unlock_dir(lower_dir_dentry);
164 dput(lower_dentry);
165 return rc;
166}
167
Michael Halcrow237fead2006-10-04 02:16:22 -0700168/**
Michael Halcrow237fead2006-10-04 02:16:22 -0700169 * ecryptfs_do_create
170 * @directory_inode: inode of the new file's dentry's parent in ecryptfs
171 * @ecryptfs_dentry: New file's dentry in ecryptfs
172 * @mode: The mode of the new file
173 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
174 *
175 * Creates the underlying file and the eCryptfs inode which will link to
176 * it. It will also update the eCryptfs directory inode to mimic the
177 * stat of the lower directory inode.
178 *
Tyler Hicksb59db432011-11-21 17:31:02 -0600179 * Returns the new eCryptfs inode on success; an ERR_PTR on error condition
Michael Halcrow237fead2006-10-04 02:16:22 -0700180 */
Tyler Hicksb59db432011-11-21 17:31:02 -0600181static struct inode *
Michael Halcrow237fead2006-10-04 02:16:22 -0700182ecryptfs_do_create(struct inode *directory_inode,
Al Viro175a4eb2011-07-26 03:30:54 -0400183 struct dentry *ecryptfs_dentry, umode_t mode)
Michael Halcrow237fead2006-10-04 02:16:22 -0700184{
185 int rc;
186 struct dentry *lower_dentry;
187 struct dentry *lower_dir_dentry;
Tyler Hicksb59db432011-11-21 17:31:02 -0600188 struct inode *inode;
Michael Halcrow237fead2006-10-04 02:16:22 -0700189
190 lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
191 lower_dir_dentry = lock_parent(lower_dentry);
Al Viro312b63f2012-06-10 18:09:36 -0400192 rc = vfs_create(lower_dir_dentry->d_inode, lower_dentry, mode, true);
Michael Halcrow4981e082007-10-16 01:28:09 -0700193 if (rc) {
Michael Halcrowcaeeeec2008-01-08 15:33:02 -0800194 printk(KERN_ERR "%s: Failure to create dentry in lower fs; "
Harvey Harrison18d1dbf2008-04-29 00:59:48 -0700195 "rc = [%d]\n", __func__, rc);
Tyler Hicksb59db432011-11-21 17:31:02 -0600196 inode = ERR_PTR(rc);
Michael Halcrowcaeeeec2008-01-08 15:33:02 -0800197 goto out_lock;
Michael Halcrow237fead2006-10-04 02:16:22 -0700198 }
Tyler Hicksb59db432011-11-21 17:31:02 -0600199 inode = __ecryptfs_get_inode(lower_dentry->d_inode,
200 directory_inode->i_sb);
Tyler Hicks8bc2d3c2012-05-22 15:09:50 -0500201 if (IS_ERR(inode)) {
J. Bruce Fieldsb21996e2011-09-20 09:14:34 -0400202 vfs_unlink(lower_dir_dentry->d_inode, lower_dentry, NULL);
Michael Halcrow237fead2006-10-04 02:16:22 -0700203 goto out_lock;
Tyler Hicks8bc2d3c2012-05-22 15:09:50 -0500204 }
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -0800205 fsstack_copy_attr_times(directory_inode, lower_dir_dentry->d_inode);
206 fsstack_copy_inode_size(directory_inode, lower_dir_dentry->d_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700207out_lock:
208 unlock_dir(lower_dir_dentry);
Tyler Hicksb59db432011-11-21 17:31:02 -0600209 return inode;
Michael Halcrow237fead2006-10-04 02:16:22 -0700210}
211
212/**
Michael Halcrow237fead2006-10-04 02:16:22 -0700213 * ecryptfs_initialize_file
214 *
215 * Cause the file to be changed from a basic empty file to an ecryptfs
216 * file with a header and first data page.
217 *
218 * Returns zero on success
219 */
Tyler Hickse3ccaa92012-06-20 23:50:59 -0700220int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry,
221 struct inode *ecryptfs_inode)
Michael Halcrow237fead2006-10-04 02:16:22 -0700222{
Michael Halcrowd7cdc5f2007-10-16 01:28:10 -0700223 struct ecryptfs_crypt_stat *crypt_stat =
Tyler Hicksb59db432011-11-21 17:31:02 -0600224 &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat;
Michael Halcrow237fead2006-10-04 02:16:22 -0700225 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -0700226
Tyler Hicksb59db432011-11-21 17:31:02 -0600227 if (S_ISDIR(ecryptfs_inode->i_mode)) {
Michael Halcrow237fead2006-10-04 02:16:22 -0700228 ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
Michael Halcrowe2bd99e2007-02-12 00:53:49 -0800229 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
Michael Halcrowd7cdc5f2007-10-16 01:28:10 -0700230 goto out;
Michael Halcrow237fead2006-10-04 02:16:22 -0700231 }
Michael Halcrow237fead2006-10-04 02:16:22 -0700232 ecryptfs_printk(KERN_DEBUG, "Initializing crypto context\n");
Tyler Hicksb59db432011-11-21 17:31:02 -0600233 rc = ecryptfs_new_file_context(ecryptfs_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700234 if (rc) {
Michael Halcrowd7cdc5f2007-10-16 01:28:10 -0700235 ecryptfs_printk(KERN_ERR, "Error creating new file "
236 "context; rc = [%d]\n", rc);
237 goto out;
Michael Halcrow237fead2006-10-04 02:16:22 -0700238 }
Tyler Hicksb59db432011-11-21 17:31:02 -0600239 rc = ecryptfs_get_lower_file(ecryptfs_dentry, ecryptfs_inode);
Roberto Sassu27992892010-11-03 11:11:28 +0100240 if (rc) {
241 printk(KERN_ERR "%s: Error attempting to initialize "
Tyler Hicks332ab162011-04-14 15:35:11 -0500242 "the lower file for the dentry with name "
David Howells9e78d142013-12-10 15:26:48 +0000243 "[%pd]; rc = [%d]\n", __func__,
244 ecryptfs_dentry, rc);
Roberto Sassu27992892010-11-03 11:11:28 +0100245 goto out;
Michael Halcrow391b52f2008-07-23 21:30:08 -0700246 }
Tyler Hicksb59db432011-11-21 17:31:02 -0600247 rc = ecryptfs_write_metadata(ecryptfs_dentry, ecryptfs_inode);
Tyler Hicks332ab162011-04-14 15:35:11 -0500248 if (rc)
Michael Halcrowd7cdc5f2007-10-16 01:28:10 -0700249 printk(KERN_ERR "Error writing headers; rc = [%d]\n", rc);
Tyler Hicksb59db432011-11-21 17:31:02 -0600250 ecryptfs_put_lower_file(ecryptfs_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700251out:
252 return rc;
253}
254
255/**
256 * ecryptfs_create
257 * @dir: The inode of the directory in which to create the file.
258 * @dentry: The eCryptfs dentry
259 * @mode: The mode of the new file.
Michael Halcrow237fead2006-10-04 02:16:22 -0700260 *
261 * Creates a new file.
262 *
263 * Returns zero on success; non-zero on error condition
264 */
265static int
266ecryptfs_create(struct inode *directory_inode, struct dentry *ecryptfs_dentry,
Al Viroebfc3b42012-06-10 18:05:36 -0400267 umode_t mode, bool excl)
Michael Halcrow237fead2006-10-04 02:16:22 -0700268{
Tyler Hicksb59db432011-11-21 17:31:02 -0600269 struct inode *ecryptfs_inode;
Michael Halcrow237fead2006-10-04 02:16:22 -0700270 int rc;
271
Tyler Hicksb59db432011-11-21 17:31:02 -0600272 ecryptfs_inode = ecryptfs_do_create(directory_inode, ecryptfs_dentry,
273 mode);
274 if (unlikely(IS_ERR(ecryptfs_inode))) {
Michael Halcrow237fead2006-10-04 02:16:22 -0700275 ecryptfs_printk(KERN_WARNING, "Failed to create file in"
276 "lower filesystem\n");
Tyler Hicksb59db432011-11-21 17:31:02 -0600277 rc = PTR_ERR(ecryptfs_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700278 goto out;
279 }
280 /* At this point, a file exists on "disk"; we need to make sure
281 * that this on disk file is prepared to be an ecryptfs file */
Tyler Hicksb59db432011-11-21 17:31:02 -0600282 rc = ecryptfs_initialize_file(ecryptfs_dentry, ecryptfs_inode);
283 if (rc) {
Tyler Hicks8bc2d3c2012-05-22 15:09:50 -0500284 ecryptfs_do_unlink(directory_inode, ecryptfs_dentry,
285 ecryptfs_inode);
286 make_bad_inode(ecryptfs_inode);
Tyler Hicksb59db432011-11-21 17:31:02 -0600287 unlock_new_inode(ecryptfs_inode);
288 iput(ecryptfs_inode);
289 goto out;
290 }
Tyler Hicksb59db432011-11-21 17:31:02 -0600291 unlock_new_inode(ecryptfs_inode);
Al Viro8fc37ec2012-07-19 09:18:15 +0400292 d_instantiate(ecryptfs_dentry, ecryptfs_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700293out:
294 return rc;
295}
296
Tyler Hicks778aeb42011-05-24 04:56:23 -0500297static int ecryptfs_i_size_read(struct dentry *dentry, struct inode *inode)
Michael Halcrow237fead2006-10-04 02:16:22 -0700298{
Tyler Hicks2aac0cf2009-03-20 02:23:57 -0500299 struct ecryptfs_crypt_stat *crypt_stat;
Tyler Hicks778aeb42011-05-24 04:56:23 -0500300 int rc;
Michael Halcrow237fead2006-10-04 02:16:22 -0700301
Tyler Hicks778aeb42011-05-24 04:56:23 -0500302 rc = ecryptfs_get_lower_file(dentry, inode);
Roberto Sassu27992892010-11-03 11:11:28 +0100303 if (rc) {
304 printk(KERN_ERR "%s: Error attempting to initialize "
Tyler Hicks332ab162011-04-14 15:35:11 -0500305 "the lower file for the dentry with name "
David Howells9e78d142013-12-10 15:26:48 +0000306 "[%pd]; rc = [%d]\n", __func__,
307 dentry, rc);
Tyler Hicks778aeb42011-05-24 04:56:23 -0500308 return rc;
Michael Halcrow391b52f2008-07-23 21:30:08 -0700309 }
Tyler Hicks778aeb42011-05-24 04:56:23 -0500310
Tyler Hicks3b06b3e2011-05-24 03:49:02 -0500311 crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
Tyler Hicks2aac0cf2009-03-20 02:23:57 -0500312 /* TODO: lock for crypt_stat comparison */
313 if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED))
Tyler Hicks778aeb42011-05-24 04:56:23 -0500314 ecryptfs_set_default_sizes(crypt_stat);
315
316 rc = ecryptfs_read_and_validate_header_region(inode);
317 ecryptfs_put_lower_file(inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700318 if (rc) {
Tyler Hicks778aeb42011-05-24 04:56:23 -0500319 rc = ecryptfs_read_and_validate_xattr_region(dentry, inode);
320 if (!rc)
321 crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
Michael Halcrow237fead2006-10-04 02:16:22 -0700322 }
Tyler Hicks778aeb42011-05-24 04:56:23 -0500323
324 /* Must return 0 to allow non-eCryptfs files to be looked up, too */
325 return 0;
326}
327
328/**
329 * ecryptfs_lookup_interpose - Dentry interposition for a lookup
330 */
331static int ecryptfs_lookup_interpose(struct dentry *dentry,
332 struct dentry *lower_dentry,
333 struct inode *dir_inode)
334{
335 struct inode *inode, *lower_inode = lower_dentry->d_inode;
336 struct ecryptfs_dentry_info *dentry_info;
337 struct vfsmount *lower_mnt;
338 int rc = 0;
339
Tyler Hicks778aeb42011-05-24 04:56:23 -0500340 dentry_info = kmem_cache_alloc(ecryptfs_dentry_info_cache, GFP_KERNEL);
Tyler Hicks778aeb42011-05-24 04:56:23 -0500341 if (!dentry_info) {
342 printk(KERN_ERR "%s: Out of memory whilst attempting "
343 "to allocate ecryptfs_dentry_info struct\n",
344 __func__);
345 dput(lower_dentry);
Tyler Hicks778aeb42011-05-24 04:56:23 -0500346 return -ENOMEM;
347 }
Al Viro0b1d9012012-07-20 12:09:19 +0400348
349 lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(dentry->d_parent));
350 fsstack_copy_attr_atime(dir_inode, lower_dentry->d_parent->d_inode);
Al Viro84d08fa2013-07-05 18:59:33 +0400351 BUG_ON(!d_count(lower_dentry));
Al Viro0b1d9012012-07-20 12:09:19 +0400352
353 ecryptfs_set_dentry_private(dentry, dentry_info);
Al Viro92dd1232013-09-15 20:50:13 -0400354 dentry_info->lower_path.mnt = lower_mnt;
355 dentry_info->lower_path.dentry = lower_dentry;
Tyler Hicks778aeb42011-05-24 04:56:23 -0500356
357 if (!lower_dentry->d_inode) {
358 /* We want to add because we couldn't find in lower */
359 d_add(dentry, NULL);
360 return 0;
361 }
362 inode = __ecryptfs_get_inode(lower_inode, dir_inode->i_sb);
363 if (IS_ERR(inode)) {
364 printk(KERN_ERR "%s: Error interposing; rc = [%ld]\n",
365 __func__, PTR_ERR(inode));
366 return PTR_ERR(inode);
367 }
368 if (S_ISREG(inode->i_mode)) {
369 rc = ecryptfs_i_size_read(dentry, inode);
370 if (rc) {
371 make_bad_inode(inode);
372 return rc;
373 }
374 }
375
Tyler Hicks3b06b3e2011-05-24 03:49:02 -0500376 if (inode->i_state & I_NEW)
377 unlock_new_inode(inode);
Tyler Hicks778aeb42011-05-24 04:56:23 -0500378 d_add(dentry, inode);
379
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800380 return rc;
381}
382
383/**
384 * ecryptfs_lookup
385 * @ecryptfs_dir_inode: The eCryptfs directory inode
386 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
387 * @ecryptfs_nd: nameidata; may be NULL
388 *
389 * Find a file on disk. If the file does not exist, then we'll add it to the
390 * dentry cache and continue on to read it from the disk.
391 */
392static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
393 struct dentry *ecryptfs_dentry,
Al Viro00cd8dd2012-06-10 17:13:09 -0400394 unsigned int flags)
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800395{
396 char *encrypted_and_encoded_name = NULL;
Michael Halcrowa8f12862009-01-06 14:42:03 -0800397 size_t encrypted_and_encoded_name_size;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800398 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800399 struct dentry *lower_dir_dentry, *lower_dentry;
400 int rc = 0;
401
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800402 lower_dir_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry->d_parent);
Tyler Hicks8787c7a2011-02-17 18:51:24 -0600403 mutex_lock(&lower_dir_dentry->d_inode->i_mutex);
404 lower_dentry = lookup_one_len(ecryptfs_dentry->d_name.name,
405 lower_dir_dentry,
406 ecryptfs_dentry->d_name.len);
407 mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800408 if (IS_ERR(lower_dentry)) {
409 rc = PTR_ERR(lower_dentry);
Tyler Hicks8787c7a2011-02-17 18:51:24 -0600410 ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
David Howells9e78d142013-12-10 15:26:48 +0000411 "[%d] on lower_dentry = [%pd]\n", __func__, rc,
412 ecryptfs_dentry);
Al Virobc65a122012-07-20 12:03:41 +0400413 goto out;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800414 }
415 if (lower_dentry->d_inode)
Tyler Hicks5ccf9202011-05-24 02:16:51 -0500416 goto interpose;
Tyler Hicks2aac0cf2009-03-20 02:23:57 -0500417 mount_crypt_stat = &ecryptfs_superblock_to_private(
418 ecryptfs_dentry->d_sb)->mount_crypt_stat;
419 if (!(mount_crypt_stat
420 && (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)))
Tyler Hicks5ccf9202011-05-24 02:16:51 -0500421 goto interpose;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800422 dput(lower_dentry);
423 rc = ecryptfs_encrypt_and_encode_filename(
424 &encrypted_and_encoded_name, &encrypted_and_encoded_name_size,
Tyler Hicks2aac0cf2009-03-20 02:23:57 -0500425 NULL, mount_crypt_stat, ecryptfs_dentry->d_name.name,
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800426 ecryptfs_dentry->d_name.len);
427 if (rc) {
428 printk(KERN_ERR "%s: Error attempting to encrypt and encode "
429 "filename; rc = [%d]\n", __func__, rc);
Al Virobc65a122012-07-20 12:03:41 +0400430 goto out;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800431 }
Tyler Hicks8787c7a2011-02-17 18:51:24 -0600432 mutex_lock(&lower_dir_dentry->d_inode->i_mutex);
433 lower_dentry = lookup_one_len(encrypted_and_encoded_name,
434 lower_dir_dentry,
435 encrypted_and_encoded_name_size);
436 mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800437 if (IS_ERR(lower_dentry)) {
438 rc = PTR_ERR(lower_dentry);
Tyler Hicks8787c7a2011-02-17 18:51:24 -0600439 ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
Tyler Hicks9f376222010-03-25 11:16:56 -0500440 "[%d] on lower_dentry = [%s]\n", __func__, rc,
441 encrypted_and_encoded_name);
Al Virobc65a122012-07-20 12:03:41 +0400442 goto out;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800443 }
Tyler Hicks5ccf9202011-05-24 02:16:51 -0500444interpose:
445 rc = ecryptfs_lookup_interpose(ecryptfs_dentry, lower_dentry,
446 ecryptfs_dir_inode);
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800447out:
448 kfree(encrypted_and_encoded_name);
Michael Halcrow237fead2006-10-04 02:16:22 -0700449 return ERR_PTR(rc);
450}
451
452static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
453 struct dentry *new_dentry)
454{
455 struct dentry *lower_old_dentry;
456 struct dentry *lower_new_dentry;
457 struct dentry *lower_dir_dentry;
458 u64 file_size_save;
459 int rc;
460
461 file_size_save = i_size_read(old_dentry->d_inode);
462 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
463 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
464 dget(lower_old_dentry);
465 dget(lower_new_dentry);
466 lower_dir_dentry = lock_parent(lower_new_dentry);
467 rc = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode,
J. Bruce Fields146a8592011-09-20 17:14:31 -0400468 lower_new_dentry, NULL);
Michael Halcrow237fead2006-10-04 02:16:22 -0700469 if (rc || !lower_new_dentry->d_inode)
470 goto out_lock;
Tyler Hicks5ccf9202011-05-24 02:16:51 -0500471 rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb);
Michael Halcrow237fead2006-10-04 02:16:22 -0700472 if (rc)
473 goto out_lock;
Tyler Hicks3a8380c2010-03-23 18:09:02 -0500474 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
475 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
Miklos Szeredibfe86842011-10-28 14:13:29 +0200476 set_nlink(old_dentry->d_inode,
477 ecryptfs_inode_to_lower(old_dentry->d_inode)->i_nlink);
Michael Halcrow237fead2006-10-04 02:16:22 -0700478 i_size_write(new_dentry->d_inode, file_size_save);
479out_lock:
480 unlock_dir(lower_dir_dentry);
481 dput(lower_new_dentry);
482 dput(lower_old_dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -0700483 return rc;
484}
485
486static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
487{
Tyler Hicks8bc2d3c2012-05-22 15:09:50 -0500488 return ecryptfs_do_unlink(dir, dentry, dentry->d_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700489}
490
491static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry,
492 const char *symname)
493{
494 int rc;
495 struct dentry *lower_dentry;
496 struct dentry *lower_dir_dentry;
Michael Halcrow237fead2006-10-04 02:16:22 -0700497 char *encoded_symname;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800498 size_t encoded_symlen;
499 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
Michael Halcrow237fead2006-10-04 02:16:22 -0700500
501 lower_dentry = ecryptfs_dentry_to_lower(dentry);
502 dget(lower_dentry);
503 lower_dir_dentry = lock_parent(lower_dentry);
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800504 mount_crypt_stat = &ecryptfs_superblock_to_private(
505 dir->i_sb)->mount_crypt_stat;
506 rc = ecryptfs_encrypt_and_encode_filename(&encoded_symname,
507 &encoded_symlen,
508 NULL,
509 mount_crypt_stat, symname,
510 strlen(symname));
511 if (rc)
Michael Halcrow237fead2006-10-04 02:16:22 -0700512 goto out_lock;
Michael Halcrow237fead2006-10-04 02:16:22 -0700513 rc = vfs_symlink(lower_dir_dentry->d_inode, lower_dentry,
Miklos Szeredidb2e7472008-06-24 16:50:16 +0200514 encoded_symname);
Michael Halcrow237fead2006-10-04 02:16:22 -0700515 kfree(encoded_symname);
516 if (rc || !lower_dentry->d_inode)
517 goto out_lock;
Tyler Hicks5ccf9202011-05-24 02:16:51 -0500518 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
Michael Halcrow237fead2006-10-04 02:16:22 -0700519 if (rc)
520 goto out_lock;
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -0800521 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
522 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700523out_lock:
524 unlock_dir(lower_dir_dentry);
525 dput(lower_dentry);
526 if (!dentry->d_inode)
527 d_drop(dentry);
528 return rc;
529}
530
Al Viro18bb1db2011-07-26 01:41:39 -0400531static int ecryptfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
Michael Halcrow237fead2006-10-04 02:16:22 -0700532{
533 int rc;
534 struct dentry *lower_dentry;
535 struct dentry *lower_dir_dentry;
536
537 lower_dentry = ecryptfs_dentry_to_lower(dentry);
538 lower_dir_dentry = lock_parent(lower_dentry);
539 rc = vfs_mkdir(lower_dir_dentry->d_inode, lower_dentry, mode);
540 if (rc || !lower_dentry->d_inode)
541 goto out;
Tyler Hicks5ccf9202011-05-24 02:16:51 -0500542 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
Michael Halcrow237fead2006-10-04 02:16:22 -0700543 if (rc)
544 goto out;
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -0800545 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
546 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
Miklos Szeredibfe86842011-10-28 14:13:29 +0200547 set_nlink(dir, lower_dir_dentry->d_inode->i_nlink);
Michael Halcrow237fead2006-10-04 02:16:22 -0700548out:
549 unlock_dir(lower_dir_dentry);
550 if (!dentry->d_inode)
551 d_drop(dentry);
552 return rc;
553}
554
555static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
556{
Michael Halcrow237fead2006-10-04 02:16:22 -0700557 struct dentry *lower_dentry;
Michael Halcrow237fead2006-10-04 02:16:22 -0700558 struct dentry *lower_dir_dentry;
Michael Halcrow45ec4aba2006-10-30 22:07:20 -0800559 int rc;
Michael Halcrow237fead2006-10-04 02:16:22 -0700560
561 lower_dentry = ecryptfs_dentry_to_lower(dentry);
Michael Halcrow45ec4aba2006-10-30 22:07:20 -0800562 dget(dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -0700563 lower_dir_dentry = lock_parent(lower_dentry);
Michael Halcrow45ec4aba2006-10-30 22:07:20 -0800564 dget(lower_dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -0700565 rc = vfs_rmdir(lower_dir_dentry->d_inode, lower_dentry);
Michael Halcrow45ec4aba2006-10-30 22:07:20 -0800566 dput(lower_dentry);
Tyler Hicks07850552011-04-29 16:26:27 -0500567 if (!rc && dentry->d_inode)
568 clear_nlink(dentry->d_inode);
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -0800569 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
Miklos Szeredibfe86842011-10-28 14:13:29 +0200570 set_nlink(dir, lower_dir_dentry->d_inode->i_nlink);
Michael Halcrow237fead2006-10-04 02:16:22 -0700571 unlock_dir(lower_dir_dentry);
572 if (!rc)
573 d_drop(dentry);
Michael Halcrow45ec4aba2006-10-30 22:07:20 -0800574 dput(dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -0700575 return rc;
576}
577
578static int
Al Viro1a67aaf2011-07-26 01:52:52 -0400579ecryptfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
Michael Halcrow237fead2006-10-04 02:16:22 -0700580{
581 int rc;
582 struct dentry *lower_dentry;
583 struct dentry *lower_dir_dentry;
584
585 lower_dentry = ecryptfs_dentry_to_lower(dentry);
586 lower_dir_dentry = lock_parent(lower_dentry);
587 rc = vfs_mknod(lower_dir_dentry->d_inode, lower_dentry, mode, dev);
588 if (rc || !lower_dentry->d_inode)
589 goto out;
Tyler Hicks5ccf9202011-05-24 02:16:51 -0500590 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
Michael Halcrow237fead2006-10-04 02:16:22 -0700591 if (rc)
592 goto out;
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -0800593 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
594 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700595out:
596 unlock_dir(lower_dir_dentry);
597 if (!dentry->d_inode)
598 d_drop(dentry);
599 return rc;
600}
601
602static int
603ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
604 struct inode *new_dir, struct dentry *new_dentry)
605{
606 int rc;
607 struct dentry *lower_old_dentry;
608 struct dentry *lower_new_dentry;
609 struct dentry *lower_old_dir_dentry;
610 struct dentry *lower_new_dir_dentry;
Erez Zadok0d132f72009-12-05 21:17:09 -0500611 struct dentry *trap = NULL;
Tyler Hicks8335eaf2012-09-13 12:00:56 -0700612 struct inode *target_inode;
Michael Halcrow237fead2006-10-04 02:16:22 -0700613
614 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
615 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
616 dget(lower_old_dentry);
617 dget(lower_new_dentry);
618 lower_old_dir_dentry = dget_parent(lower_old_dentry);
619 lower_new_dir_dentry = dget_parent(lower_new_dentry);
Tyler Hicks8335eaf2012-09-13 12:00:56 -0700620 target_inode = new_dentry->d_inode;
Erez Zadok0d132f72009-12-05 21:17:09 -0500621 trap = lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
622 /* source should not be ancestor of target */
623 if (trap == lower_old_dentry) {
624 rc = -EINVAL;
625 goto out_lock;
626 }
627 /* target should not be ancestor of source */
628 if (trap == lower_new_dentry) {
629 rc = -ENOTEMPTY;
630 goto out_lock;
631 }
Michael Halcrow237fead2006-10-04 02:16:22 -0700632 rc = vfs_rename(lower_old_dir_dentry->d_inode, lower_old_dentry,
J. Bruce Fields8e6d7822011-09-20 16:59:58 -0400633 lower_new_dir_dentry->d_inode, lower_new_dentry,
Miklos Szeredi520c8b12014-04-01 17:08:42 +0200634 NULL, 0);
Michael Halcrow237fead2006-10-04 02:16:22 -0700635 if (rc)
636 goto out_lock;
Tyler Hicks8335eaf2012-09-13 12:00:56 -0700637 if (target_inode)
638 fsstack_copy_attr_all(target_inode,
639 ecryptfs_inode_to_lower(target_inode));
Erez Zadok9afa2fb2009-12-02 19:51:54 -0500640 fsstack_copy_attr_all(new_dir, lower_new_dir_dentry->d_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700641 if (new_dir != old_dir)
Erez Zadok9afa2fb2009-12-02 19:51:54 -0500642 fsstack_copy_attr_all(old_dir, lower_old_dir_dentry->d_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700643out_lock:
644 unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
Tyler Hicksdd55c8982011-04-12 11:23:09 -0500645 dput(lower_new_dir_dentry);
646 dput(lower_old_dir_dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -0700647 dput(lower_new_dentry);
648 dput(lower_old_dentry);
649 return rc;
650}
651
Al Virob22e8fe2013-11-29 22:51:47 -0500652static char *ecryptfs_readlink_lower(struct dentry *dentry, size_t *bufsiz)
Michael Halcrow237fead2006-10-04 02:16:22 -0700653{
Tyler Hicks3a60a162010-03-22 00:41:35 -0500654 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -0700655 char *lower_buf;
Al Virob22e8fe2013-11-29 22:51:47 -0500656 char *buf;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800657 mm_segment_t old_fs;
658 int rc;
Michael Halcrow237fead2006-10-04 02:16:22 -0700659
Al Viro408bd622012-05-03 09:34:20 -0400660 lower_buf = kmalloc(PATH_MAX, GFP_KERNEL);
Al Virob22e8fe2013-11-29 22:51:47 -0500661 if (!lower_buf)
662 return ERR_PTR(-ENOMEM);
Michael Halcrow237fead2006-10-04 02:16:22 -0700663 old_fs = get_fs();
664 set_fs(get_ds());
Michael Halcrow237fead2006-10-04 02:16:22 -0700665 rc = lower_dentry->d_inode->i_op->readlink(lower_dentry,
666 (char __user *)lower_buf,
Al Viro408bd622012-05-03 09:34:20 -0400667 PATH_MAX);
Michael Halcrow237fead2006-10-04 02:16:22 -0700668 set_fs(old_fs);
Tyler Hicks3a60a162010-03-22 00:41:35 -0500669 if (rc < 0)
670 goto out;
Al Virob22e8fe2013-11-29 22:51:47 -0500671 rc = ecryptfs_decode_and_decrypt_filename(&buf, bufsiz, dentry->d_sb,
Al Viro408bd622012-05-03 09:34:20 -0400672 lower_buf, rc);
Tyler Hicks3a60a162010-03-22 00:41:35 -0500673out:
Michael Halcrow237fead2006-10-04 02:16:22 -0700674 kfree(lower_buf);
Al Virob22e8fe2013-11-29 22:51:47 -0500675 return rc ? ERR_PTR(rc) : buf;
Tyler Hicks3a60a162010-03-22 00:41:35 -0500676}
677
Michael Halcrow237fead2006-10-04 02:16:22 -0700678static void *ecryptfs_follow_link(struct dentry *dentry, struct nameidata *nd)
679{
Al Virob22e8fe2013-11-29 22:51:47 -0500680 size_t len;
681 char *buf = ecryptfs_readlink_lower(dentry, &len);
682 if (IS_ERR(buf))
Michael Halcrow237fead2006-10-04 02:16:22 -0700683 goto out;
Al Viro408bd622012-05-03 09:34:20 -0400684 fsstack_copy_attr_atime(dentry->d_inode,
685 ecryptfs_dentry_to_lower(dentry)->d_inode);
686 buf[len] = '\0';
Michael Halcrow237fead2006-10-04 02:16:22 -0700687out:
OGAWA Hirofumi806892e2010-01-12 03:36:14 +0900688 nd_set_link(nd, buf);
689 return NULL;
Michael Halcrow237fead2006-10-04 02:16:22 -0700690}
691
Michael Halcrow237fead2006-10-04 02:16:22 -0700692/**
693 * upper_size_to_lower_size
694 * @crypt_stat: Crypt_stat associated with file
695 * @upper_size: Size of the upper file
696 *
Michael Halcrowcc11bef2008-02-06 01:38:32 -0800697 * Calculate the required size of the lower file based on the
Michael Halcrow237fead2006-10-04 02:16:22 -0700698 * specified size of the upper file. This calculation is based on the
699 * number of headers in the underlying file and the extent size.
700 *
701 * Returns Calculated size of the lower file.
702 */
703static loff_t
704upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
705 loff_t upper_size)
706{
707 loff_t lower_size;
708
Tyler Hicks157f1072010-02-11 07:10:38 -0600709 lower_size = ecryptfs_lower_header_size(crypt_stat);
Michael Halcrow237fead2006-10-04 02:16:22 -0700710 if (upper_size != 0) {
711 loff_t num_extents;
712
713 num_extents = upper_size >> crypt_stat->extent_shift;
714 if (upper_size & ~crypt_stat->extent_mask)
715 num_extents++;
716 lower_size += (num_extents * crypt_stat->extent_size);
717 }
718 return lower_size;
719}
720
721/**
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500722 * truncate_upper
Michael Halcrow237fead2006-10-04 02:16:22 -0700723 * @dentry: The ecryptfs layer dentry
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500724 * @ia: Address of the ecryptfs inode's attributes
725 * @lower_ia: Address of the lower inode's attributes
Michael Halcrow237fead2006-10-04 02:16:22 -0700726 *
727 * Function to handle truncations modifying the size of the file. Note
728 * that the file sizes are interpolated. When expanding, we are simply
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500729 * writing strings of 0's out. When truncating, we truncate the upper
730 * inode and update the lower_ia according to the page index
731 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
732 * the caller must use lower_ia in a call to notify_change() to perform
733 * the truncation of the lower inode.
Michael Halcrow237fead2006-10-04 02:16:22 -0700734 *
735 * Returns zero on success; non-zero otherwise
736 */
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500737static int truncate_upper(struct dentry *dentry, struct iattr *ia,
738 struct iattr *lower_ia)
Michael Halcrow237fead2006-10-04 02:16:22 -0700739{
740 int rc = 0;
741 struct inode *inode = dentry->d_inode;
Michael Halcrow237fead2006-10-04 02:16:22 -0700742 struct ecryptfs_crypt_stat *crypt_stat;
743 loff_t i_size = i_size_read(inode);
744 loff_t lower_size_before_truncate;
745 loff_t lower_size_after_truncate;
746
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500747 if (unlikely((ia->ia_size == i_size))) {
748 lower_ia->ia_valid &= ~ATTR_SIZE;
Tyler Hicks332ab162011-04-14 15:35:11 -0500749 return 0;
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500750 }
Tyler Hicks3b06b3e2011-05-24 03:49:02 -0500751 rc = ecryptfs_get_lower_file(dentry, inode);
Tyler Hicks332ab162011-04-14 15:35:11 -0500752 if (rc)
753 return rc;
Michael Halcrow237fead2006-10-04 02:16:22 -0700754 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
Michael Halcrow237fead2006-10-04 02:16:22 -0700755 /* Switch on growing or shrinking file */
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500756 if (ia->ia_size > i_size) {
Michael Halcrow2ed92552007-10-16 01:28:10 -0700757 char zero[] = { 0x00 };
Michael Halcrow240e2df2007-06-27 14:09:44 -0700758
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500759 lower_ia->ia_valid &= ~ATTR_SIZE;
Michael Halcrow2ed92552007-10-16 01:28:10 -0700760 /* Write a single 0 at the last position of the file;
761 * this triggers code that will fill in 0's throughout
762 * the intermediate portion of the previous end of the
763 * file and the new and of the file */
Al Viro48c1e442010-05-21 11:09:58 -0400764 rc = ecryptfs_write(inode, zero,
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500765 (ia->ia_size - 1), 1);
766 } else { /* ia->ia_size < i_size_read(inode) */
767 /* We're chopping off all the pages down to the page
768 * in which ia->ia_size is located. Fill in the end of
769 * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
Michael Halcrow2ed92552007-10-16 01:28:10 -0700770 * PAGE_CACHE_SIZE with zeros. */
771 size_t num_zeros = (PAGE_CACHE_SIZE
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500772 - (ia->ia_size & ~PAGE_CACHE_MASK));
Michael Halcrow2ed92552007-10-16 01:28:10 -0700773
Tyler Hicks13a791b2009-04-13 15:29:27 -0500774 if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
Christoph Hellwig2c27c652010-06-04 11:30:04 +0200775 truncate_setsize(inode, ia->ia_size);
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500776 lower_ia->ia_size = ia->ia_size;
777 lower_ia->ia_valid |= ATTR_SIZE;
Al Viro48c1e442010-05-21 11:09:58 -0400778 goto out;
Tyler Hicks13a791b2009-04-13 15:29:27 -0500779 }
Michael Halcrow2ed92552007-10-16 01:28:10 -0700780 if (num_zeros) {
781 char *zeros_virt;
782
783 zeros_virt = kzalloc(num_zeros, GFP_KERNEL);
784 if (!zeros_virt) {
785 rc = -ENOMEM;
Al Viro48c1e442010-05-21 11:09:58 -0400786 goto out;
Michael Halcrow2ed92552007-10-16 01:28:10 -0700787 }
Al Viro48c1e442010-05-21 11:09:58 -0400788 rc = ecryptfs_write(inode, zeros_virt,
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500789 ia->ia_size, num_zeros);
Michael Halcrow2ed92552007-10-16 01:28:10 -0700790 kfree(zeros_virt);
Michael Halcrow5dda6992007-10-16 01:28:06 -0700791 if (rc) {
Michael Halcrow240e2df2007-06-27 14:09:44 -0700792 printk(KERN_ERR "Error attempting to zero out "
793 "the remainder of the end page on "
794 "reducing truncate; rc = [%d]\n", rc);
Al Viro48c1e442010-05-21 11:09:58 -0400795 goto out;
Michael Halcrow240e2df2007-06-27 14:09:44 -0700796 }
797 }
Christoph Hellwig2c27c652010-06-04 11:30:04 +0200798 truncate_setsize(inode, ia->ia_size);
Michael Halcrow0216f7f2007-10-16 01:28:08 -0700799 rc = ecryptfs_write_inode_size_to_metadata(inode);
Michael Halcrowdd2a3b72007-02-12 00:53:46 -0800800 if (rc) {
801 printk(KERN_ERR "Problem with "
802 "ecryptfs_write_inode_size_to_metadata; "
803 "rc = [%d]\n", rc);
Al Viro48c1e442010-05-21 11:09:58 -0400804 goto out;
Michael Halcrowdd2a3b72007-02-12 00:53:46 -0800805 }
Michael Halcrow237fead2006-10-04 02:16:22 -0700806 /* We are reducing the size of the ecryptfs file, and need to
807 * know if we need to reduce the size of the lower file. */
808 lower_size_before_truncate =
809 upper_size_to_lower_size(crypt_stat, i_size);
810 lower_size_after_truncate =
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500811 upper_size_to_lower_size(crypt_stat, ia->ia_size);
812 if (lower_size_after_truncate < lower_size_before_truncate) {
813 lower_ia->ia_size = lower_size_after_truncate;
814 lower_ia->ia_valid |= ATTR_SIZE;
815 } else
816 lower_ia->ia_valid &= ~ATTR_SIZE;
Michael Halcrow237fead2006-10-04 02:16:22 -0700817 }
Michael Halcrow237fead2006-10-04 02:16:22 -0700818out:
Tyler Hicks332ab162011-04-14 15:35:11 -0500819 ecryptfs_put_lower_file(inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700820 return rc;
821}
822
Tyler Hicksa261a032012-01-19 20:33:44 -0600823static int ecryptfs_inode_newsize_ok(struct inode *inode, loff_t offset)
824{
825 struct ecryptfs_crypt_stat *crypt_stat;
826 loff_t lower_oldsize, lower_newsize;
827
828 crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
829 lower_oldsize = upper_size_to_lower_size(crypt_stat,
830 i_size_read(inode));
831 lower_newsize = upper_size_to_lower_size(crypt_stat, offset);
832 if (lower_newsize > lower_oldsize) {
833 /*
834 * The eCryptfs inode and the new *lower* size are mixed here
835 * because we may not have the lower i_mutex held and/or it may
836 * not be appropriate to call inode_newsize_ok() with inodes
837 * from other filesystems.
838 */
839 return inode_newsize_ok(inode, lower_newsize);
840 }
841
842 return 0;
843}
844
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500845/**
846 * ecryptfs_truncate
847 * @dentry: The ecryptfs layer dentry
848 * @new_length: The length to expand the file to
849 *
850 * Simple function that handles the truncation of an eCryptfs inode and
851 * its corresponding lower inode.
852 *
853 * Returns zero on success; non-zero otherwise
854 */
855int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
856{
857 struct iattr ia = { .ia_valid = ATTR_SIZE, .ia_size = new_length };
858 struct iattr lower_ia = { .ia_valid = 0 };
859 int rc;
860
Tyler Hicksa261a032012-01-19 20:33:44 -0600861 rc = ecryptfs_inode_newsize_ok(dentry->d_inode, new_length);
862 if (rc)
863 return rc;
864
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500865 rc = truncate_upper(dentry, &ia, &lower_ia);
866 if (!rc && lower_ia.ia_valid & ATTR_SIZE) {
867 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
868
869 mutex_lock(&lower_dentry->d_inode->i_mutex);
J. Bruce Fields27ac0ff2011-09-20 17:19:26 -0400870 rc = notify_change(lower_dentry, &lower_ia, NULL);
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500871 mutex_unlock(&lower_dentry->d_inode->i_mutex);
872 }
873 return rc;
874}
875
Michael Halcrow237fead2006-10-04 02:16:22 -0700876static int
Al Viro10556cb2011-06-20 19:28:19 -0400877ecryptfs_permission(struct inode *inode, int mask)
Michael Halcrow237fead2006-10-04 02:16:22 -0700878{
Al Virof419a2e2008-07-22 00:07:17 -0400879 return inode_permission(ecryptfs_inode_to_lower(inode), mask);
Michael Halcrow237fead2006-10-04 02:16:22 -0700880}
881
882/**
883 * ecryptfs_setattr
884 * @dentry: dentry handle to the inode to modify
885 * @ia: Structure with flags of what to change and values
886 *
887 * Updates the metadata of an inode. If the update is to the size
888 * i.e. truncation, then ecryptfs_truncate will handle the size modification
889 * of both the ecryptfs inode and the lower inode.
890 *
891 * All other metadata changes will be passed right to the lower filesystem,
892 * and we will just update our inode to look like the lower.
893 */
894static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
895{
896 int rc = 0;
897 struct dentry *lower_dentry;
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500898 struct iattr lower_ia;
Michael Halcrow237fead2006-10-04 02:16:22 -0700899 struct inode *inode;
900 struct inode *lower_inode;
901 struct ecryptfs_crypt_stat *crypt_stat;
902
903 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
Michael Halcrowe10f2812007-06-27 14:09:44 -0700904 if (!(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED))
905 ecryptfs_init_crypt_stat(crypt_stat);
Michael Halcrow237fead2006-10-04 02:16:22 -0700906 inode = dentry->d_inode;
907 lower_inode = ecryptfs_inode_to_lower(inode);
Michael Halcrowe10f2812007-06-27 14:09:44 -0700908 lower_dentry = ecryptfs_dentry_to_lower(dentry);
909 mutex_lock(&crypt_stat->cs_mutex);
David Howellse36cb0b2015-01-29 12:02:35 +0000910 if (d_is_dir(dentry))
Michael Halcrowe10f2812007-06-27 14:09:44 -0700911 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
David Howellse36cb0b2015-01-29 12:02:35 +0000912 else if (d_is_reg(dentry)
Michael Halcrow64ee4802007-07-19 01:47:54 -0700913 && (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
914 || !(crypt_stat->flags & ECRYPTFS_KEY_VALID))) {
Michael Halcrowe10f2812007-06-27 14:09:44 -0700915 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
Michael Halcrowe10f2812007-06-27 14:09:44 -0700916
Michael Halcrowe10f2812007-06-27 14:09:44 -0700917 mount_crypt_stat = &ecryptfs_superblock_to_private(
918 dentry->d_sb)->mount_crypt_stat;
Tyler Hicks3b06b3e2011-05-24 03:49:02 -0500919 rc = ecryptfs_get_lower_file(dentry, inode);
Tyler Hicks332ab162011-04-14 15:35:11 -0500920 if (rc) {
921 mutex_unlock(&crypt_stat->cs_mutex);
922 goto out;
923 }
Michael Halcrowd7cdc5f2007-10-16 01:28:10 -0700924 rc = ecryptfs_read_metadata(dentry);
Tyler Hicks332ab162011-04-14 15:35:11 -0500925 ecryptfs_put_lower_file(inode);
Michael Halcrow5dda6992007-10-16 01:28:06 -0700926 if (rc) {
Michael Halcrowe10f2812007-06-27 14:09:44 -0700927 if (!(mount_crypt_stat->flags
928 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
929 rc = -EIO;
Michael Halcrow25bd8172008-02-06 01:38:35 -0800930 printk(KERN_WARNING "Either the lower file "
Michael Halcrowe10f2812007-06-27 14:09:44 -0700931 "is not in a valid eCryptfs format, "
Michael Halcrow25bd8172008-02-06 01:38:35 -0800932 "or the key could not be retrieved. "
933 "Plaintext passthrough mode is not "
Michael Halcrowe10f2812007-06-27 14:09:44 -0700934 "enabled; returning -EIO\n");
Michael Halcrowe10f2812007-06-27 14:09:44 -0700935 mutex_unlock(&crypt_stat->cs_mutex);
Michael Halcrowe10f2812007-06-27 14:09:44 -0700936 goto out;
937 }
938 rc = 0;
Tyler Hicks3aeb86e2011-03-15 14:54:00 -0500939 crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED
940 | ECRYPTFS_ENCRYPTED);
Michael Halcrowe10f2812007-06-27 14:09:44 -0700941 }
Michael Halcrowe10f2812007-06-27 14:09:44 -0700942 }
943 mutex_unlock(&crypt_stat->cs_mutex);
Tyler Hicksa261a032012-01-19 20:33:44 -0600944
945 rc = inode_change_ok(inode, ia);
946 if (rc)
947 goto out;
948 if (ia->ia_valid & ATTR_SIZE) {
949 rc = ecryptfs_inode_newsize_ok(inode, ia->ia_size);
950 if (rc)
951 goto out;
952 }
953
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500954 memcpy(&lower_ia, ia, sizeof(lower_ia));
955 if (ia->ia_valid & ATTR_FILE)
956 lower_ia.ia_file = ecryptfs_file_to_lower(ia->ia_file);
Michael Halcrow237fead2006-10-04 02:16:22 -0700957 if (ia->ia_valid & ATTR_SIZE) {
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500958 rc = truncate_upper(dentry, ia, &lower_ia);
Michael Halcrow237fead2006-10-04 02:16:22 -0700959 if (rc < 0)
960 goto out;
961 }
Jeff Layton1ac564e2007-10-18 03:05:17 -0700962
963 /*
964 * mode change is for clearing setuid/setgid bits. Allow lower fs
965 * to interpret this in its own way.
966 */
Tyler Hicks5f3ef642009-10-14 16:18:27 -0500967 if (lower_ia.ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
968 lower_ia.ia_valid &= ~ATTR_MODE;
Jeff Layton1ac564e2007-10-18 03:05:17 -0700969
Miklos Szeredi9c3580a2008-04-29 00:59:48 -0700970 mutex_lock(&lower_dentry->d_inode->i_mutex);
J. Bruce Fields27ac0ff2011-09-20 17:19:26 -0400971 rc = notify_change(lower_dentry, &lower_ia, NULL);
Miklos Szeredi9c3580a2008-04-29 00:59:48 -0700972 mutex_unlock(&lower_dentry->d_inode->i_mutex);
Michael Halcrow237fead2006-10-04 02:16:22 -0700973out:
Erez Zadok9afa2fb2009-12-02 19:51:54 -0500974 fsstack_copy_attr_all(inode, lower_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700975 return rc;
976}
977
Tyler Hicks111d61a2013-01-17 12:19:35 -0800978static int ecryptfs_getattr_link(struct vfsmount *mnt, struct dentry *dentry,
979 struct kstat *stat)
Tyler Hicks3a60a162010-03-22 00:41:35 -0500980{
981 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
982 int rc = 0;
983
984 mount_crypt_stat = &ecryptfs_superblock_to_private(
985 dentry->d_sb)->mount_crypt_stat;
986 generic_fillattr(dentry->d_inode, stat);
987 if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) {
988 char *target;
989 size_t targetsiz;
990
Al Virob22e8fe2013-11-29 22:51:47 -0500991 target = ecryptfs_readlink_lower(dentry, &targetsiz);
992 if (!IS_ERR(target)) {
Tyler Hicks3a60a162010-03-22 00:41:35 -0500993 kfree(target);
994 stat->size = targetsiz;
Al Virob22e8fe2013-11-29 22:51:47 -0500995 } else {
996 rc = PTR_ERR(target);
Tyler Hicks3a60a162010-03-22 00:41:35 -0500997 }
998 }
999 return rc;
1000}
1001
Tyler Hicks111d61a2013-01-17 12:19:35 -08001002static int ecryptfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
1003 struct kstat *stat)
Tyler Hicksf8f484d2009-11-04 02:48:01 -06001004{
1005 struct kstat lower_stat;
1006 int rc;
1007
Al Viro3dadecc2013-01-24 02:18:08 -05001008 rc = vfs_getattr(ecryptfs_dentry_to_lower_path(dentry), &lower_stat);
Tyler Hicksf8f484d2009-11-04 02:48:01 -06001009 if (!rc) {
Tyler Hicks55f9cf62011-01-11 12:43:42 -06001010 fsstack_copy_attr_all(dentry->d_inode,
1011 ecryptfs_inode_to_lower(dentry->d_inode));
Tyler Hicksf8f484d2009-11-04 02:48:01 -06001012 generic_fillattr(dentry->d_inode, stat);
1013 stat->blocks = lower_stat.blocks;
1014 }
1015 return rc;
1016}
1017
Michael Halcrowdd2a3b72007-02-12 00:53:46 -08001018int
Michael Halcrow237fead2006-10-04 02:16:22 -07001019ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value,
1020 size_t size, int flags)
1021{
1022 int rc = 0;
1023 struct dentry *lower_dentry;
1024
1025 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1026 if (!lower_dentry->d_inode->i_op->setxattr) {
Christian Pulvermachercfce08c2010-03-23 11:51:38 -05001027 rc = -EOPNOTSUPP;
Michael Halcrow237fead2006-10-04 02:16:22 -07001028 goto out;
1029 }
Roberto Sassu48b512e2010-10-05 18:53:45 +02001030
1031 rc = vfs_setxattr(lower_dentry, name, value, size, flags);
Chao Yu35425ea2014-07-24 17:25:42 +08001032 if (!rc && dentry->d_inode)
Tyler Hicks545d6802012-02-07 17:55:40 -06001033 fsstack_copy_attr_all(dentry->d_inode, lower_dentry->d_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -07001034out:
1035 return rc;
1036}
1037
Michael Halcrowdd2a3b72007-02-12 00:53:46 -08001038ssize_t
Michael Halcrowd7cdc5f2007-10-16 01:28:10 -07001039ecryptfs_getxattr_lower(struct dentry *lower_dentry, const char *name,
1040 void *value, size_t size)
1041{
1042 int rc = 0;
1043
1044 if (!lower_dentry->d_inode->i_op->getxattr) {
Christian Pulvermachercfce08c2010-03-23 11:51:38 -05001045 rc = -EOPNOTSUPP;
Michael Halcrowd7cdc5f2007-10-16 01:28:10 -07001046 goto out;
1047 }
1048 mutex_lock(&lower_dentry->d_inode->i_mutex);
1049 rc = lower_dentry->d_inode->i_op->getxattr(lower_dentry, name, value,
1050 size);
1051 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1052out:
1053 return rc;
1054}
1055
Adrian Bunk7896b632008-02-06 01:38:32 -08001056static ssize_t
Michael Halcrow237fead2006-10-04 02:16:22 -07001057ecryptfs_getxattr(struct dentry *dentry, const char *name, void *value,
1058 size_t size)
1059{
Michael Halcrow2ed92552007-10-16 01:28:10 -07001060 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry), name,
1061 value, size);
Michael Halcrow237fead2006-10-04 02:16:22 -07001062}
1063
1064static ssize_t
1065ecryptfs_listxattr(struct dentry *dentry, char *list, size_t size)
1066{
1067 int rc = 0;
1068 struct dentry *lower_dentry;
1069
1070 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1071 if (!lower_dentry->d_inode->i_op->listxattr) {
Christian Pulvermachercfce08c2010-03-23 11:51:38 -05001072 rc = -EOPNOTSUPP;
Michael Halcrow237fead2006-10-04 02:16:22 -07001073 goto out;
1074 }
1075 mutex_lock(&lower_dentry->d_inode->i_mutex);
1076 rc = lower_dentry->d_inode->i_op->listxattr(lower_dentry, list, size);
1077 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1078out:
1079 return rc;
1080}
1081
1082static int ecryptfs_removexattr(struct dentry *dentry, const char *name)
1083{
1084 int rc = 0;
1085 struct dentry *lower_dentry;
1086
1087 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1088 if (!lower_dentry->d_inode->i_op->removexattr) {
Christian Pulvermachercfce08c2010-03-23 11:51:38 -05001089 rc = -EOPNOTSUPP;
Michael Halcrow237fead2006-10-04 02:16:22 -07001090 goto out;
1091 }
1092 mutex_lock(&lower_dentry->d_inode->i_mutex);
1093 rc = lower_dentry->d_inode->i_op->removexattr(lower_dentry, name);
1094 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1095out:
1096 return rc;
1097}
1098
Arjan van de Ven754661f2007-02-12 00:55:38 -08001099const struct inode_operations ecryptfs_symlink_iops = {
Al Viro408bd622012-05-03 09:34:20 -04001100 .readlink = generic_readlink,
Michael Halcrow237fead2006-10-04 02:16:22 -07001101 .follow_link = ecryptfs_follow_link,
Al Viro87dc8002013-09-16 10:30:04 -04001102 .put_link = kfree_put_link,
Michael Halcrow237fead2006-10-04 02:16:22 -07001103 .permission = ecryptfs_permission,
1104 .setattr = ecryptfs_setattr,
Tyler Hicks3a60a162010-03-22 00:41:35 -05001105 .getattr = ecryptfs_getattr_link,
Michael Halcrow237fead2006-10-04 02:16:22 -07001106 .setxattr = ecryptfs_setxattr,
1107 .getxattr = ecryptfs_getxattr,
1108 .listxattr = ecryptfs_listxattr,
1109 .removexattr = ecryptfs_removexattr
1110};
1111
Arjan van de Ven754661f2007-02-12 00:55:38 -08001112const struct inode_operations ecryptfs_dir_iops = {
Michael Halcrow237fead2006-10-04 02:16:22 -07001113 .create = ecryptfs_create,
1114 .lookup = ecryptfs_lookup,
1115 .link = ecryptfs_link,
1116 .unlink = ecryptfs_unlink,
1117 .symlink = ecryptfs_symlink,
1118 .mkdir = ecryptfs_mkdir,
1119 .rmdir = ecryptfs_rmdir,
1120 .mknod = ecryptfs_mknod,
1121 .rename = ecryptfs_rename,
1122 .permission = ecryptfs_permission,
1123 .setattr = ecryptfs_setattr,
1124 .setxattr = ecryptfs_setxattr,
1125 .getxattr = ecryptfs_getxattr,
1126 .listxattr = ecryptfs_listxattr,
1127 .removexattr = ecryptfs_removexattr
1128};
1129
Arjan van de Ven754661f2007-02-12 00:55:38 -08001130const struct inode_operations ecryptfs_main_iops = {
Michael Halcrow237fead2006-10-04 02:16:22 -07001131 .permission = ecryptfs_permission,
1132 .setattr = ecryptfs_setattr,
Tyler Hicksf8f484d2009-11-04 02:48:01 -06001133 .getattr = ecryptfs_getattr,
Michael Halcrow237fead2006-10-04 02:16:22 -07001134 .setxattr = ecryptfs_setxattr,
1135 .getxattr = ecryptfs_getxattr,
1136 .listxattr = ecryptfs_listxattr,
1137 .removexattr = ecryptfs_removexattr
1138};