Merge branch 'devel-stable' of master.kernel.org:/home/rmk/linux-2.6-arm
[pandora-kernel.git] / fs / ecryptfs / inode.c
1 /**
2  * eCryptfs: Linux filesystem encryption layer
3  *
4  * Copyright (C) 1997-2004 Erez Zadok
5  * Copyright (C) 2001-2004 Stony Brook University
6  * Copyright (C) 2004-2007 International Business Machines Corp.
7  *   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>
33 #include <linux/fs_stack.h>
34 #include <linux/slab.h>
35 #include <linux/xattr.h>
36 #include <asm/unaligned.h>
37 #include "ecryptfs_kernel.h"
38
39 static struct dentry *lock_parent(struct dentry *dentry)
40 {
41         struct dentry *dir;
42
43         dir = dget_parent(dentry);
44         mutex_lock_nested(&(dir->d_inode->i_mutex), I_MUTEX_PARENT);
45         return dir;
46 }
47
48 static void unlock_dir(struct dentry *dir)
49 {
50         mutex_unlock(&dir->d_inode->i_mutex);
51         dput(dir);
52 }
53
54 /**
55  * ecryptfs_create_underlying_file
56  * @lower_dir_inode: inode of the parent in the lower fs of the new file
57  * @dentry: New file's dentry
58  * @mode: The mode of the new file
59  * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
60  *
61  * Creates the file in the lower file system.
62  *
63  * Returns zero on success; non-zero on error condition
64  */
65 static int
66 ecryptfs_create_underlying_file(struct inode *lower_dir_inode,
67                                 struct dentry *dentry, int mode,
68                                 struct nameidata *nd)
69 {
70         struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
71         struct vfsmount *lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry);
72         struct dentry *dentry_save;
73         struct vfsmount *vfsmount_save;
74         unsigned int flags_save;
75         int rc;
76
77         dentry_save = nd->path.dentry;
78         vfsmount_save = nd->path.mnt;
79         flags_save = nd->flags;
80         nd->path.dentry = lower_dentry;
81         nd->path.mnt = lower_mnt;
82         nd->flags &= ~LOOKUP_OPEN;
83         rc = vfs_create(lower_dir_inode, lower_dentry, mode, nd);
84         nd->path.dentry = dentry_save;
85         nd->path.mnt = vfsmount_save;
86         nd->flags = flags_save;
87         return rc;
88 }
89
90 /**
91  * ecryptfs_do_create
92  * @directory_inode: inode of the new file's dentry's parent in ecryptfs
93  * @ecryptfs_dentry: New file's dentry in ecryptfs
94  * @mode: The mode of the new file
95  * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
96  *
97  * Creates the underlying file and the eCryptfs inode which will link to
98  * it. It will also update the eCryptfs directory inode to mimic the
99  * stat of the lower directory inode.
100  *
101  * Returns zero on success; non-zero on error condition
102  */
103 static int
104 ecryptfs_do_create(struct inode *directory_inode,
105                    struct dentry *ecryptfs_dentry, int mode,
106                    struct nameidata *nd)
107 {
108         int rc;
109         struct dentry *lower_dentry;
110         struct dentry *lower_dir_dentry;
111
112         lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
113         lower_dir_dentry = lock_parent(lower_dentry);
114         if (IS_ERR(lower_dir_dentry)) {
115                 ecryptfs_printk(KERN_ERR, "Error locking directory of "
116                                 "dentry\n");
117                 rc = PTR_ERR(lower_dir_dentry);
118                 goto out;
119         }
120         rc = ecryptfs_create_underlying_file(lower_dir_dentry->d_inode,
121                                              ecryptfs_dentry, mode, nd);
122         if (rc) {
123                 printk(KERN_ERR "%s: Failure to create dentry in lower fs; "
124                        "rc = [%d]\n", __func__, rc);
125                 goto out_lock;
126         }
127         rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry,
128                                 directory_inode->i_sb, 0);
129         if (rc) {
130                 ecryptfs_printk(KERN_ERR, "Failure in ecryptfs_interpose\n");
131                 goto out_lock;
132         }
133         fsstack_copy_attr_times(directory_inode, lower_dir_dentry->d_inode);
134         fsstack_copy_inode_size(directory_inode, lower_dir_dentry->d_inode);
135 out_lock:
136         unlock_dir(lower_dir_dentry);
137 out:
138         return rc;
139 }
140
141 /**
142  * grow_file
143  * @ecryptfs_dentry: the eCryptfs dentry
144  *
145  * This is the code which will grow the file to its correct size.
146  */
147 static int grow_file(struct dentry *ecryptfs_dentry)
148 {
149         struct inode *ecryptfs_inode = ecryptfs_dentry->d_inode;
150         char zero_virt[] = { 0x00 };
151         int rc = 0;
152
153         rc = ecryptfs_write(ecryptfs_inode, zero_virt, 0, 1);
154         i_size_write(ecryptfs_inode, 0);
155         rc = ecryptfs_write_inode_size_to_metadata(ecryptfs_inode);
156         ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat.flags |=
157                 ECRYPTFS_NEW_FILE;
158         return rc;
159 }
160
161 /**
162  * ecryptfs_initialize_file
163  *
164  * Cause the file to be changed from a basic empty file to an ecryptfs
165  * file with a header and first data page.
166  *
167  * Returns zero on success
168  */
169 static int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry)
170 {
171         struct ecryptfs_crypt_stat *crypt_stat =
172                 &ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat;
173         int rc = 0;
174
175         if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) {
176                 ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
177                 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
178                 goto out;
179         }
180         crypt_stat->flags |= ECRYPTFS_NEW_FILE;
181         ecryptfs_printk(KERN_DEBUG, "Initializing crypto context\n");
182         rc = ecryptfs_new_file_context(ecryptfs_dentry);
183         if (rc) {
184                 ecryptfs_printk(KERN_ERR, "Error creating new file "
185                                 "context; rc = [%d]\n", rc);
186                 goto out;
187         }
188         if (!ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->lower_file) {
189                 rc = ecryptfs_init_persistent_file(ecryptfs_dentry);
190                 if (rc) {
191                         printk(KERN_ERR "%s: Error attempting to initialize "
192                                "the persistent file for the dentry with name "
193                                "[%s]; rc = [%d]\n", __func__,
194                                ecryptfs_dentry->d_name.name, rc);
195                         goto out;
196                 }
197         }
198         rc = ecryptfs_write_metadata(ecryptfs_dentry);
199         if (rc) {
200                 printk(KERN_ERR "Error writing headers; rc = [%d]\n", rc);
201                 goto out;
202         }
203         rc = grow_file(ecryptfs_dentry);
204         if (rc)
205                 printk(KERN_ERR "Error growing file; rc = [%d]\n", rc);
206 out:
207         return rc;
208 }
209
210 /**
211  * ecryptfs_create
212  * @dir: The inode of the directory in which to create the file.
213  * @dentry: The eCryptfs dentry
214  * @mode: The mode of the new file.
215  * @nd: nameidata
216  *
217  * Creates a new file.
218  *
219  * Returns zero on success; non-zero on error condition
220  */
221 static int
222 ecryptfs_create(struct inode *directory_inode, struct dentry *ecryptfs_dentry,
223                 int mode, struct nameidata *nd)
224 {
225         int rc;
226
227         /* ecryptfs_do_create() calls ecryptfs_interpose() */
228         rc = ecryptfs_do_create(directory_inode, ecryptfs_dentry, mode, nd);
229         if (unlikely(rc)) {
230                 ecryptfs_printk(KERN_WARNING, "Failed to create file in"
231                                 "lower filesystem\n");
232                 goto out;
233         }
234         /* At this point, a file exists on "disk"; we need to make sure
235          * that this on disk file is prepared to be an ecryptfs file */
236         rc = ecryptfs_initialize_file(ecryptfs_dentry);
237 out:
238         return rc;
239 }
240
241 /**
242  * ecryptfs_lookup_and_interpose_lower - Perform a lookup
243  */
244 int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
245                                         struct dentry *lower_dentry,
246                                         struct inode *ecryptfs_dir_inode,
247                                         struct nameidata *ecryptfs_nd)
248 {
249         struct dentry *lower_dir_dentry;
250         struct vfsmount *lower_mnt;
251         struct inode *lower_inode;
252         struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
253         struct ecryptfs_crypt_stat *crypt_stat;
254         char *page_virt = NULL;
255         u64 file_size;
256         int rc = 0;
257
258         lower_dir_dentry = lower_dentry->d_parent;
259         lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(
260                                    ecryptfs_dentry->d_parent));
261         lower_inode = lower_dentry->d_inode;
262         fsstack_copy_attr_atime(ecryptfs_dir_inode, lower_dir_dentry->d_inode);
263         BUG_ON(!lower_dentry->d_count);
264         ecryptfs_set_dentry_private(ecryptfs_dentry,
265                                     kmem_cache_alloc(ecryptfs_dentry_info_cache,
266                                                      GFP_KERNEL));
267         if (!ecryptfs_dentry_to_private(ecryptfs_dentry)) {
268                 rc = -ENOMEM;
269                 printk(KERN_ERR "%s: Out of memory whilst attempting "
270                        "to allocate ecryptfs_dentry_info struct\n",
271                         __func__);
272                 goto out_put;
273         }
274         ecryptfs_set_dentry_lower(ecryptfs_dentry, lower_dentry);
275         ecryptfs_set_dentry_lower_mnt(ecryptfs_dentry, lower_mnt);
276         if (!lower_dentry->d_inode) {
277                 /* We want to add because we couldn't find in lower */
278                 d_add(ecryptfs_dentry, NULL);
279                 goto out;
280         }
281         rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry,
282                                 ecryptfs_dir_inode->i_sb,
283                                 ECRYPTFS_INTERPOSE_FLAG_D_ADD);
284         if (rc) {
285                 printk(KERN_ERR "%s: Error interposing; rc = [%d]\n",
286                        __func__, rc);
287                 goto out;
288         }
289         if (S_ISDIR(lower_inode->i_mode))
290                 goto out;
291         if (S_ISLNK(lower_inode->i_mode))
292                 goto out;
293         if (special_file(lower_inode->i_mode))
294                 goto out;
295         if (!ecryptfs_nd)
296                 goto out;
297         /* Released in this function */
298         page_virt = kmem_cache_zalloc(ecryptfs_header_cache_2, GFP_USER);
299         if (!page_virt) {
300                 printk(KERN_ERR "%s: Cannot kmem_cache_zalloc() a page\n",
301                        __func__);
302                 rc = -ENOMEM;
303                 goto out;
304         }
305         if (!ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->lower_file) {
306                 rc = ecryptfs_init_persistent_file(ecryptfs_dentry);
307                 if (rc) {
308                         printk(KERN_ERR "%s: Error attempting to initialize "
309                                "the persistent file for the dentry with name "
310                                "[%s]; rc = [%d]\n", __func__,
311                                ecryptfs_dentry->d_name.name, rc);
312                         goto out_free_kmem;
313                 }
314         }
315         crypt_stat = &ecryptfs_inode_to_private(
316                                         ecryptfs_dentry->d_inode)->crypt_stat;
317         /* TODO: lock for crypt_stat comparison */
318         if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED))
319                         ecryptfs_set_default_sizes(crypt_stat);
320         rc = ecryptfs_read_and_validate_header_region(page_virt,
321                                                       ecryptfs_dentry->d_inode);
322         if (rc) {
323                 memset(page_virt, 0, PAGE_CACHE_SIZE);
324                 rc = ecryptfs_read_and_validate_xattr_region(page_virt,
325                                                              ecryptfs_dentry);
326                 if (rc) {
327                         rc = 0;
328                         goto out_free_kmem;
329                 }
330                 crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
331         }
332         mount_crypt_stat = &ecryptfs_superblock_to_private(
333                 ecryptfs_dentry->d_sb)->mount_crypt_stat;
334         if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) {
335                 if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
336                         file_size = (crypt_stat->metadata_size
337                                      + i_size_read(lower_dentry->d_inode));
338                 else
339                         file_size = i_size_read(lower_dentry->d_inode);
340         } else {
341                 file_size = get_unaligned_be64(page_virt);
342         }
343         i_size_write(ecryptfs_dentry->d_inode, (loff_t)file_size);
344 out_free_kmem:
345         kmem_cache_free(ecryptfs_header_cache_2, page_virt);
346         goto out;
347 out_put:
348         dput(lower_dentry);
349         mntput(lower_mnt);
350         d_drop(ecryptfs_dentry);
351 out:
352         return rc;
353 }
354
355 /**
356  * ecryptfs_new_lower_dentry
357  * @name: The name of the new dentry.
358  * @lower_dir_dentry: Parent directory of the new dentry.
359  * @nd: nameidata from last lookup.
360  *
361  * Create a new dentry or get it from lower parent dir.
362  */
363 static struct dentry *
364 ecryptfs_new_lower_dentry(struct qstr *name, struct dentry *lower_dir_dentry,
365                           struct nameidata *nd)
366 {
367         struct dentry *new_dentry;
368         struct dentry *tmp;
369         struct inode *lower_dir_inode;
370
371         lower_dir_inode = lower_dir_dentry->d_inode;
372
373         tmp = d_alloc(lower_dir_dentry, name);
374         if (!tmp)
375                 return ERR_PTR(-ENOMEM);
376
377         mutex_lock(&lower_dir_inode->i_mutex);
378         new_dentry = lower_dir_inode->i_op->lookup(lower_dir_inode, tmp, nd);
379         mutex_unlock(&lower_dir_inode->i_mutex);
380
381         if (!new_dentry)
382                 new_dentry = tmp;
383         else
384                 dput(tmp);
385
386         return new_dentry;
387 }
388
389
390 /**
391  * ecryptfs_lookup_one_lower
392  * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
393  * @lower_dir_dentry: lower parent directory
394  * @name: lower file name
395  *
396  * Get the lower dentry from vfs. If lower dentry does not exist yet,
397  * create it.
398  */
399 static struct dentry *
400 ecryptfs_lookup_one_lower(struct dentry *ecryptfs_dentry,
401                           struct dentry *lower_dir_dentry, struct qstr *name)
402 {
403         struct nameidata nd;
404         struct vfsmount *lower_mnt;
405         int err;
406
407         lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(
408                                     ecryptfs_dentry->d_parent));
409         err = vfs_path_lookup(lower_dir_dentry, lower_mnt, name->name , 0, &nd);
410         mntput(lower_mnt);
411
412         if (!err) {
413                 /* we dont need the mount */
414                 mntput(nd.path.mnt);
415                 return nd.path.dentry;
416         }
417         if (err != -ENOENT)
418                 return ERR_PTR(err);
419
420         /* create a new lower dentry */
421         return ecryptfs_new_lower_dentry(name, lower_dir_dentry, &nd);
422 }
423
424 /**
425  * ecryptfs_lookup
426  * @ecryptfs_dir_inode: The eCryptfs directory inode
427  * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
428  * @ecryptfs_nd: nameidata; may be NULL
429  *
430  * Find a file on disk. If the file does not exist, then we'll add it to the
431  * dentry cache and continue on to read it from the disk.
432  */
433 static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
434                                       struct dentry *ecryptfs_dentry,
435                                       struct nameidata *ecryptfs_nd)
436 {
437         char *encrypted_and_encoded_name = NULL;
438         size_t encrypted_and_encoded_name_size;
439         struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
440         struct dentry *lower_dir_dentry, *lower_dentry;
441         struct qstr lower_name;
442         int rc = 0;
443
444         if ((ecryptfs_dentry->d_name.len == 1
445              && !strcmp(ecryptfs_dentry->d_name.name, "."))
446             || (ecryptfs_dentry->d_name.len == 2
447                 && !strcmp(ecryptfs_dentry->d_name.name, ".."))) {
448                 goto out_d_drop;
449         }
450         lower_dir_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry->d_parent);
451         lower_name.name = ecryptfs_dentry->d_name.name;
452         lower_name.len = ecryptfs_dentry->d_name.len;
453         lower_name.hash = ecryptfs_dentry->d_name.hash;
454         if (lower_dir_dentry->d_op && lower_dir_dentry->d_op->d_hash) {
455                 rc = lower_dir_dentry->d_op->d_hash(lower_dir_dentry,
456                                 lower_dir_dentry->d_inode, &lower_name);
457                 if (rc < 0)
458                         goto out_d_drop;
459         }
460         lower_dentry = ecryptfs_lookup_one_lower(ecryptfs_dentry,
461                                                  lower_dir_dentry, &lower_name);
462         if (IS_ERR(lower_dentry)) {
463                 rc = PTR_ERR(lower_dentry);
464                 ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_lower() returned "
465                                 "[%d] on lower_dentry = [%s]\n", __func__, rc,
466                                 encrypted_and_encoded_name);
467                 goto out_d_drop;
468         }
469         if (lower_dentry->d_inode)
470                 goto lookup_and_interpose;
471         mount_crypt_stat = &ecryptfs_superblock_to_private(
472                                 ecryptfs_dentry->d_sb)->mount_crypt_stat;
473         if (!(mount_crypt_stat
474             && (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)))
475                 goto lookup_and_interpose;
476         dput(lower_dentry);
477         rc = ecryptfs_encrypt_and_encode_filename(
478                 &encrypted_and_encoded_name, &encrypted_and_encoded_name_size,
479                 NULL, mount_crypt_stat, ecryptfs_dentry->d_name.name,
480                 ecryptfs_dentry->d_name.len);
481         if (rc) {
482                 printk(KERN_ERR "%s: Error attempting to encrypt and encode "
483                        "filename; rc = [%d]\n", __func__, rc);
484                 goto out_d_drop;
485         }
486         lower_name.name = encrypted_and_encoded_name;
487         lower_name.len = encrypted_and_encoded_name_size;
488         lower_name.hash = full_name_hash(lower_name.name, lower_name.len);
489         if (lower_dir_dentry->d_op && lower_dir_dentry->d_op->d_hash) {
490                 rc = lower_dir_dentry->d_op->d_hash(lower_dir_dentry,
491                                 lower_dir_dentry->d_inode, &lower_name);
492                 if (rc < 0)
493                         goto out_d_drop;
494         }
495         lower_dentry = ecryptfs_lookup_one_lower(ecryptfs_dentry,
496                                                  lower_dir_dentry, &lower_name);
497         if (IS_ERR(lower_dentry)) {
498                 rc = PTR_ERR(lower_dentry);
499                 ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_lower() returned "
500                                 "[%d] on lower_dentry = [%s]\n", __func__, rc,
501                                 encrypted_and_encoded_name);
502                 goto out_d_drop;
503         }
504 lookup_and_interpose:
505         rc = ecryptfs_lookup_and_interpose_lower(ecryptfs_dentry, lower_dentry,
506                                                  ecryptfs_dir_inode,
507                                                  ecryptfs_nd);
508         goto out;
509 out_d_drop:
510         d_drop(ecryptfs_dentry);
511 out:
512         kfree(encrypted_and_encoded_name);
513         return ERR_PTR(rc);
514 }
515
516 static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
517                          struct dentry *new_dentry)
518 {
519         struct dentry *lower_old_dentry;
520         struct dentry *lower_new_dentry;
521         struct dentry *lower_dir_dentry;
522         u64 file_size_save;
523         int rc;
524
525         file_size_save = i_size_read(old_dentry->d_inode);
526         lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
527         lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
528         dget(lower_old_dentry);
529         dget(lower_new_dentry);
530         lower_dir_dentry = lock_parent(lower_new_dentry);
531         rc = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode,
532                       lower_new_dentry);
533         if (rc || !lower_new_dentry->d_inode)
534                 goto out_lock;
535         rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb, 0);
536         if (rc)
537                 goto out_lock;
538         fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
539         fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
540         old_dentry->d_inode->i_nlink =
541                 ecryptfs_inode_to_lower(old_dentry->d_inode)->i_nlink;
542         i_size_write(new_dentry->d_inode, file_size_save);
543 out_lock:
544         unlock_dir(lower_dir_dentry);
545         dput(lower_new_dentry);
546         dput(lower_old_dentry);
547         return rc;
548 }
549
550 static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
551 {
552         int rc = 0;
553         struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
554         struct inode *lower_dir_inode = ecryptfs_inode_to_lower(dir);
555         struct dentry *lower_dir_dentry;
556
557         dget(lower_dentry);
558         lower_dir_dentry = lock_parent(lower_dentry);
559         rc = vfs_unlink(lower_dir_inode, lower_dentry);
560         if (rc) {
561                 printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc);
562                 goto out_unlock;
563         }
564         fsstack_copy_attr_times(dir, lower_dir_inode);
565         dentry->d_inode->i_nlink =
566                 ecryptfs_inode_to_lower(dentry->d_inode)->i_nlink;
567         dentry->d_inode->i_ctime = dir->i_ctime;
568         d_drop(dentry);
569 out_unlock:
570         unlock_dir(lower_dir_dentry);
571         dput(lower_dentry);
572         return rc;
573 }
574
575 static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry,
576                             const char *symname)
577 {
578         int rc;
579         struct dentry *lower_dentry;
580         struct dentry *lower_dir_dentry;
581         char *encoded_symname;
582         size_t encoded_symlen;
583         struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
584
585         lower_dentry = ecryptfs_dentry_to_lower(dentry);
586         dget(lower_dentry);
587         lower_dir_dentry = lock_parent(lower_dentry);
588         mount_crypt_stat = &ecryptfs_superblock_to_private(
589                 dir->i_sb)->mount_crypt_stat;
590         rc = ecryptfs_encrypt_and_encode_filename(&encoded_symname,
591                                                   &encoded_symlen,
592                                                   NULL,
593                                                   mount_crypt_stat, symname,
594                                                   strlen(symname));
595         if (rc)
596                 goto out_lock;
597         rc = vfs_symlink(lower_dir_dentry->d_inode, lower_dentry,
598                          encoded_symname);
599         kfree(encoded_symname);
600         if (rc || !lower_dentry->d_inode)
601                 goto out_lock;
602         rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
603         if (rc)
604                 goto out_lock;
605         fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
606         fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
607 out_lock:
608         unlock_dir(lower_dir_dentry);
609         dput(lower_dentry);
610         if (!dentry->d_inode)
611                 d_drop(dentry);
612         return rc;
613 }
614
615 static int ecryptfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
616 {
617         int rc;
618         struct dentry *lower_dentry;
619         struct dentry *lower_dir_dentry;
620
621         lower_dentry = ecryptfs_dentry_to_lower(dentry);
622         lower_dir_dentry = lock_parent(lower_dentry);
623         rc = vfs_mkdir(lower_dir_dentry->d_inode, lower_dentry, mode);
624         if (rc || !lower_dentry->d_inode)
625                 goto out;
626         rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
627         if (rc)
628                 goto out;
629         fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
630         fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
631         dir->i_nlink = lower_dir_dentry->d_inode->i_nlink;
632 out:
633         unlock_dir(lower_dir_dentry);
634         if (!dentry->d_inode)
635                 d_drop(dentry);
636         return rc;
637 }
638
639 static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
640 {
641         struct dentry *lower_dentry;
642         struct dentry *lower_dir_dentry;
643         int rc;
644
645         lower_dentry = ecryptfs_dentry_to_lower(dentry);
646         dget(dentry);
647         lower_dir_dentry = lock_parent(lower_dentry);
648         dget(lower_dentry);
649         rc = vfs_rmdir(lower_dir_dentry->d_inode, lower_dentry);
650         dput(lower_dentry);
651         if (!rc)
652                 d_delete(lower_dentry);
653         fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
654         dir->i_nlink = lower_dir_dentry->d_inode->i_nlink;
655         unlock_dir(lower_dir_dentry);
656         if (!rc)
657                 d_drop(dentry);
658         dput(dentry);
659         return rc;
660 }
661
662 static int
663 ecryptfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
664 {
665         int rc;
666         struct dentry *lower_dentry;
667         struct dentry *lower_dir_dentry;
668
669         lower_dentry = ecryptfs_dentry_to_lower(dentry);
670         lower_dir_dentry = lock_parent(lower_dentry);
671         rc = vfs_mknod(lower_dir_dentry->d_inode, lower_dentry, mode, dev);
672         if (rc || !lower_dentry->d_inode)
673                 goto out;
674         rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
675         if (rc)
676                 goto out;
677         fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
678         fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
679 out:
680         unlock_dir(lower_dir_dentry);
681         if (!dentry->d_inode)
682                 d_drop(dentry);
683         return rc;
684 }
685
686 static int
687 ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
688                 struct inode *new_dir, struct dentry *new_dentry)
689 {
690         int rc;
691         struct dentry *lower_old_dentry;
692         struct dentry *lower_new_dentry;
693         struct dentry *lower_old_dir_dentry;
694         struct dentry *lower_new_dir_dentry;
695         struct dentry *trap = NULL;
696
697         lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
698         lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
699         dget(lower_old_dentry);
700         dget(lower_new_dentry);
701         lower_old_dir_dentry = dget_parent(lower_old_dentry);
702         lower_new_dir_dentry = dget_parent(lower_new_dentry);
703         trap = lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
704         /* source should not be ancestor of target */
705         if (trap == lower_old_dentry) {
706                 rc = -EINVAL;
707                 goto out_lock;
708         }
709         /* target should not be ancestor of source */
710         if (trap == lower_new_dentry) {
711                 rc = -ENOTEMPTY;
712                 goto out_lock;
713         }
714         rc = vfs_rename(lower_old_dir_dentry->d_inode, lower_old_dentry,
715                         lower_new_dir_dentry->d_inode, lower_new_dentry);
716         if (rc)
717                 goto out_lock;
718         fsstack_copy_attr_all(new_dir, lower_new_dir_dentry->d_inode);
719         if (new_dir != old_dir)
720                 fsstack_copy_attr_all(old_dir, lower_old_dir_dentry->d_inode);
721 out_lock:
722         unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
723         dput(lower_new_dentry->d_parent);
724         dput(lower_old_dentry->d_parent);
725         dput(lower_new_dentry);
726         dput(lower_old_dentry);
727         return rc;
728 }
729
730 static int ecryptfs_readlink_lower(struct dentry *dentry, char **buf,
731                                    size_t *bufsiz)
732 {
733         struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
734         char *lower_buf;
735         size_t lower_bufsiz = PATH_MAX;
736         mm_segment_t old_fs;
737         int rc;
738
739         lower_buf = kmalloc(lower_bufsiz, GFP_KERNEL);
740         if (!lower_buf) {
741                 rc = -ENOMEM;
742                 goto out;
743         }
744         old_fs = get_fs();
745         set_fs(get_ds());
746         rc = lower_dentry->d_inode->i_op->readlink(lower_dentry,
747                                                    (char __user *)lower_buf,
748                                                    lower_bufsiz);
749         set_fs(old_fs);
750         if (rc < 0)
751                 goto out;
752         lower_bufsiz = rc;
753         rc = ecryptfs_decode_and_decrypt_filename(buf, bufsiz, dentry,
754                                                   lower_buf, lower_bufsiz);
755 out:
756         kfree(lower_buf);
757         return rc;
758 }
759
760 static int
761 ecryptfs_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
762 {
763         char *kbuf;
764         size_t kbufsiz, copied;
765         int rc;
766
767         rc = ecryptfs_readlink_lower(dentry, &kbuf, &kbufsiz);
768         if (rc)
769                 goto out;
770         copied = min_t(size_t, bufsiz, kbufsiz);
771         rc = copy_to_user(buf, kbuf, copied) ? -EFAULT : copied;
772         kfree(kbuf);
773         fsstack_copy_attr_atime(dentry->d_inode,
774                                 ecryptfs_dentry_to_lower(dentry)->d_inode);
775 out:
776         return rc;
777 }
778
779 static void *ecryptfs_follow_link(struct dentry *dentry, struct nameidata *nd)
780 {
781         char *buf;
782         int len = PAGE_SIZE, rc;
783         mm_segment_t old_fs;
784
785         /* Released in ecryptfs_put_link(); only release here on error */
786         buf = kmalloc(len, GFP_KERNEL);
787         if (!buf) {
788                 buf = ERR_PTR(-ENOMEM);
789                 goto out;
790         }
791         old_fs = get_fs();
792         set_fs(get_ds());
793         rc = dentry->d_inode->i_op->readlink(dentry, (char __user *)buf, len);
794         set_fs(old_fs);
795         if (rc < 0) {
796                 kfree(buf);
797                 buf = ERR_PTR(rc);
798         } else
799                 buf[rc] = '\0';
800 out:
801         nd_set_link(nd, buf);
802         return NULL;
803 }
804
805 static void
806 ecryptfs_put_link(struct dentry *dentry, struct nameidata *nd, void *ptr)
807 {
808         char *buf = nd_get_link(nd);
809         if (!IS_ERR(buf)) {
810                 /* Free the char* */
811                 kfree(buf);
812         }
813 }
814
815 /**
816  * upper_size_to_lower_size
817  * @crypt_stat: Crypt_stat associated with file
818  * @upper_size: Size of the upper file
819  *
820  * Calculate the required size of the lower file based on the
821  * specified size of the upper file. This calculation is based on the
822  * number of headers in the underlying file and the extent size.
823  *
824  * Returns Calculated size of the lower file.
825  */
826 static loff_t
827 upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
828                          loff_t upper_size)
829 {
830         loff_t lower_size;
831
832         lower_size = ecryptfs_lower_header_size(crypt_stat);
833         if (upper_size != 0) {
834                 loff_t num_extents;
835
836                 num_extents = upper_size >> crypt_stat->extent_shift;
837                 if (upper_size & ~crypt_stat->extent_mask)
838                         num_extents++;
839                 lower_size += (num_extents * crypt_stat->extent_size);
840         }
841         return lower_size;
842 }
843
844 /**
845  * truncate_upper
846  * @dentry: The ecryptfs layer dentry
847  * @ia: Address of the ecryptfs inode's attributes
848  * @lower_ia: Address of the lower inode's attributes
849  *
850  * Function to handle truncations modifying the size of the file. Note
851  * that the file sizes are interpolated. When expanding, we are simply
852  * writing strings of 0's out. When truncating, we truncate the upper
853  * inode and update the lower_ia according to the page index
854  * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
855  * the caller must use lower_ia in a call to notify_change() to perform
856  * the truncation of the lower inode.
857  *
858  * Returns zero on success; non-zero otherwise
859  */
860 static int truncate_upper(struct dentry *dentry, struct iattr *ia,
861                           struct iattr *lower_ia)
862 {
863         int rc = 0;
864         struct inode *inode = dentry->d_inode;
865         struct ecryptfs_crypt_stat *crypt_stat;
866         loff_t i_size = i_size_read(inode);
867         loff_t lower_size_before_truncate;
868         loff_t lower_size_after_truncate;
869
870         if (unlikely((ia->ia_size == i_size))) {
871                 lower_ia->ia_valid &= ~ATTR_SIZE;
872                 goto out;
873         }
874         crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
875         /* Switch on growing or shrinking file */
876         if (ia->ia_size > i_size) {
877                 char zero[] = { 0x00 };
878
879                 lower_ia->ia_valid &= ~ATTR_SIZE;
880                 /* Write a single 0 at the last position of the file;
881                  * this triggers code that will fill in 0's throughout
882                  * the intermediate portion of the previous end of the
883                  * file and the new and of the file */
884                 rc = ecryptfs_write(inode, zero,
885                                     (ia->ia_size - 1), 1);
886         } else { /* ia->ia_size < i_size_read(inode) */
887                 /* We're chopping off all the pages down to the page
888                  * in which ia->ia_size is located. Fill in the end of
889                  * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
890                  * PAGE_CACHE_SIZE with zeros. */
891                 size_t num_zeros = (PAGE_CACHE_SIZE
892                                     - (ia->ia_size & ~PAGE_CACHE_MASK));
893
894
895                 /*
896                  * XXX(truncate) this should really happen at the begginning
897                  * of ->setattr.  But the code is too messy to that as part
898                  * of a larger patch.  ecryptfs is also totally missing out
899                  * on the inode_change_ok check at the beginning of
900                  * ->setattr while would include this.
901                  */
902                 rc = inode_newsize_ok(inode, ia->ia_size);
903                 if (rc)
904                         goto out;
905
906                 if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
907                         truncate_setsize(inode, ia->ia_size);
908                         lower_ia->ia_size = ia->ia_size;
909                         lower_ia->ia_valid |= ATTR_SIZE;
910                         goto out;
911                 }
912                 if (num_zeros) {
913                         char *zeros_virt;
914
915                         zeros_virt = kzalloc(num_zeros, GFP_KERNEL);
916                         if (!zeros_virt) {
917                                 rc = -ENOMEM;
918                                 goto out;
919                         }
920                         rc = ecryptfs_write(inode, zeros_virt,
921                                             ia->ia_size, num_zeros);
922                         kfree(zeros_virt);
923                         if (rc) {
924                                 printk(KERN_ERR "Error attempting to zero out "
925                                        "the remainder of the end page on "
926                                        "reducing truncate; rc = [%d]\n", rc);
927                                 goto out;
928                         }
929                 }
930                 truncate_setsize(inode, ia->ia_size);
931                 rc = ecryptfs_write_inode_size_to_metadata(inode);
932                 if (rc) {
933                         printk(KERN_ERR "Problem with "
934                                "ecryptfs_write_inode_size_to_metadata; "
935                                "rc = [%d]\n", rc);
936                         goto out;
937                 }
938                 /* We are reducing the size of the ecryptfs file, and need to
939                  * know if we need to reduce the size of the lower file. */
940                 lower_size_before_truncate =
941                     upper_size_to_lower_size(crypt_stat, i_size);
942                 lower_size_after_truncate =
943                     upper_size_to_lower_size(crypt_stat, ia->ia_size);
944                 if (lower_size_after_truncate < lower_size_before_truncate) {
945                         lower_ia->ia_size = lower_size_after_truncate;
946                         lower_ia->ia_valid |= ATTR_SIZE;
947                 } else
948                         lower_ia->ia_valid &= ~ATTR_SIZE;
949         }
950 out:
951         return rc;
952 }
953
954 /**
955  * ecryptfs_truncate
956  * @dentry: The ecryptfs layer dentry
957  * @new_length: The length to expand the file to
958  *
959  * Simple function that handles the truncation of an eCryptfs inode and
960  * its corresponding lower inode.
961  *
962  * Returns zero on success; non-zero otherwise
963  */
964 int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
965 {
966         struct iattr ia = { .ia_valid = ATTR_SIZE, .ia_size = new_length };
967         struct iattr lower_ia = { .ia_valid = 0 };
968         int rc;
969
970         rc = truncate_upper(dentry, &ia, &lower_ia);
971         if (!rc && lower_ia.ia_valid & ATTR_SIZE) {
972                 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
973
974                 mutex_lock(&lower_dentry->d_inode->i_mutex);
975                 rc = notify_change(lower_dentry, &lower_ia);
976                 mutex_unlock(&lower_dentry->d_inode->i_mutex);
977         }
978         return rc;
979 }
980
981 static int
982 ecryptfs_permission(struct inode *inode, int mask, unsigned int flags)
983 {
984         if (flags & IPERM_FLAG_RCU)
985                 return -ECHILD;
986         return inode_permission(ecryptfs_inode_to_lower(inode), mask);
987 }
988
989 /**
990  * ecryptfs_setattr
991  * @dentry: dentry handle to the inode to modify
992  * @ia: Structure with flags of what to change and values
993  *
994  * Updates the metadata of an inode. If the update is to the size
995  * i.e. truncation, then ecryptfs_truncate will handle the size modification
996  * of both the ecryptfs inode and the lower inode.
997  *
998  * All other metadata changes will be passed right to the lower filesystem,
999  * and we will just update our inode to look like the lower.
1000  */
1001 static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
1002 {
1003         int rc = 0;
1004         struct dentry *lower_dentry;
1005         struct iattr lower_ia;
1006         struct inode *inode;
1007         struct inode *lower_inode;
1008         struct ecryptfs_crypt_stat *crypt_stat;
1009
1010         crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
1011         if (!(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED))
1012                 ecryptfs_init_crypt_stat(crypt_stat);
1013         inode = dentry->d_inode;
1014         lower_inode = ecryptfs_inode_to_lower(inode);
1015         lower_dentry = ecryptfs_dentry_to_lower(dentry);
1016         mutex_lock(&crypt_stat->cs_mutex);
1017         if (S_ISDIR(dentry->d_inode->i_mode))
1018                 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
1019         else if (S_ISREG(dentry->d_inode->i_mode)
1020                  && (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
1021                      || !(crypt_stat->flags & ECRYPTFS_KEY_VALID))) {
1022                 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
1023
1024                 mount_crypt_stat = &ecryptfs_superblock_to_private(
1025                         dentry->d_sb)->mount_crypt_stat;
1026                 rc = ecryptfs_read_metadata(dentry);
1027                 if (rc) {
1028                         if (!(mount_crypt_stat->flags
1029                               & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
1030                                 rc = -EIO;
1031                                 printk(KERN_WARNING "Either the lower file "
1032                                        "is not in a valid eCryptfs format, "
1033                                        "or the key could not be retrieved. "
1034                                        "Plaintext passthrough mode is not "
1035                                        "enabled; returning -EIO\n");
1036                                 mutex_unlock(&crypt_stat->cs_mutex);
1037                                 goto out;
1038                         }
1039                         rc = 0;
1040                         crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
1041                 }
1042         }
1043         mutex_unlock(&crypt_stat->cs_mutex);
1044         memcpy(&lower_ia, ia, sizeof(lower_ia));
1045         if (ia->ia_valid & ATTR_FILE)
1046                 lower_ia.ia_file = ecryptfs_file_to_lower(ia->ia_file);
1047         if (ia->ia_valid & ATTR_SIZE) {
1048                 rc = truncate_upper(dentry, ia, &lower_ia);
1049                 if (rc < 0)
1050                         goto out;
1051         }
1052
1053         /*
1054          * mode change is for clearing setuid/setgid bits. Allow lower fs
1055          * to interpret this in its own way.
1056          */
1057         if (lower_ia.ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
1058                 lower_ia.ia_valid &= ~ATTR_MODE;
1059
1060         mutex_lock(&lower_dentry->d_inode->i_mutex);
1061         rc = notify_change(lower_dentry, &lower_ia);
1062         mutex_unlock(&lower_dentry->d_inode->i_mutex);
1063 out:
1064         fsstack_copy_attr_all(inode, lower_inode);
1065         return rc;
1066 }
1067
1068 int ecryptfs_getattr_link(struct vfsmount *mnt, struct dentry *dentry,
1069                           struct kstat *stat)
1070 {
1071         struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
1072         int rc = 0;
1073
1074         mount_crypt_stat = &ecryptfs_superblock_to_private(
1075                                                 dentry->d_sb)->mount_crypt_stat;
1076         generic_fillattr(dentry->d_inode, stat);
1077         if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) {
1078                 char *target;
1079                 size_t targetsiz;
1080
1081                 rc = ecryptfs_readlink_lower(dentry, &target, &targetsiz);
1082                 if (!rc) {
1083                         kfree(target);
1084                         stat->size = targetsiz;
1085                 }
1086         }
1087         return rc;
1088 }
1089
1090 int ecryptfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
1091                      struct kstat *stat)
1092 {
1093         struct kstat lower_stat;
1094         int rc;
1095
1096         rc = vfs_getattr(ecryptfs_dentry_to_lower_mnt(dentry),
1097                          ecryptfs_dentry_to_lower(dentry), &lower_stat);
1098         if (!rc) {
1099                 generic_fillattr(dentry->d_inode, stat);
1100                 stat->blocks = lower_stat.blocks;
1101         }
1102         return rc;
1103 }
1104
1105 int
1106 ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value,
1107                   size_t size, int flags)
1108 {
1109         int rc = 0;
1110         struct dentry *lower_dentry;
1111
1112         lower_dentry = ecryptfs_dentry_to_lower(dentry);
1113         if (!lower_dentry->d_inode->i_op->setxattr) {
1114                 rc = -EOPNOTSUPP;
1115                 goto out;
1116         }
1117
1118         rc = vfs_setxattr(lower_dentry, name, value, size, flags);
1119 out:
1120         return rc;
1121 }
1122
1123 ssize_t
1124 ecryptfs_getxattr_lower(struct dentry *lower_dentry, const char *name,
1125                         void *value, size_t size)
1126 {
1127         int rc = 0;
1128
1129         if (!lower_dentry->d_inode->i_op->getxattr) {
1130                 rc = -EOPNOTSUPP;
1131                 goto out;
1132         }
1133         mutex_lock(&lower_dentry->d_inode->i_mutex);
1134         rc = lower_dentry->d_inode->i_op->getxattr(lower_dentry, name, value,
1135                                                    size);
1136         mutex_unlock(&lower_dentry->d_inode->i_mutex);
1137 out:
1138         return rc;
1139 }
1140
1141 static ssize_t
1142 ecryptfs_getxattr(struct dentry *dentry, const char *name, void *value,
1143                   size_t size)
1144 {
1145         return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry), name,
1146                                        value, size);
1147 }
1148
1149 static ssize_t
1150 ecryptfs_listxattr(struct dentry *dentry, char *list, size_t size)
1151 {
1152         int rc = 0;
1153         struct dentry *lower_dentry;
1154
1155         lower_dentry = ecryptfs_dentry_to_lower(dentry);
1156         if (!lower_dentry->d_inode->i_op->listxattr) {
1157                 rc = -EOPNOTSUPP;
1158                 goto out;
1159         }
1160         mutex_lock(&lower_dentry->d_inode->i_mutex);
1161         rc = lower_dentry->d_inode->i_op->listxattr(lower_dentry, list, size);
1162         mutex_unlock(&lower_dentry->d_inode->i_mutex);
1163 out:
1164         return rc;
1165 }
1166
1167 static int ecryptfs_removexattr(struct dentry *dentry, const char *name)
1168 {
1169         int rc = 0;
1170         struct dentry *lower_dentry;
1171
1172         lower_dentry = ecryptfs_dentry_to_lower(dentry);
1173         if (!lower_dentry->d_inode->i_op->removexattr) {
1174                 rc = -EOPNOTSUPP;
1175                 goto out;
1176         }
1177         mutex_lock(&lower_dentry->d_inode->i_mutex);
1178         rc = lower_dentry->d_inode->i_op->removexattr(lower_dentry, name);
1179         mutex_unlock(&lower_dentry->d_inode->i_mutex);
1180 out:
1181         return rc;
1182 }
1183
1184 int ecryptfs_inode_test(struct inode *inode, void *candidate_lower_inode)
1185 {
1186         if ((ecryptfs_inode_to_lower(inode)
1187              == (struct inode *)candidate_lower_inode))
1188                 return 1;
1189         else
1190                 return 0;
1191 }
1192
1193 int ecryptfs_inode_set(struct inode *inode, void *lower_inode)
1194 {
1195         ecryptfs_init_inode(inode, (struct inode *)lower_inode);
1196         return 0;
1197 }
1198
1199 const struct inode_operations ecryptfs_symlink_iops = {
1200         .readlink = ecryptfs_readlink,
1201         .follow_link = ecryptfs_follow_link,
1202         .put_link = ecryptfs_put_link,
1203         .permission = ecryptfs_permission,
1204         .setattr = ecryptfs_setattr,
1205         .getattr = ecryptfs_getattr_link,
1206         .setxattr = ecryptfs_setxattr,
1207         .getxattr = ecryptfs_getxattr,
1208         .listxattr = ecryptfs_listxattr,
1209         .removexattr = ecryptfs_removexattr
1210 };
1211
1212 const struct inode_operations ecryptfs_dir_iops = {
1213         .create = ecryptfs_create,
1214         .lookup = ecryptfs_lookup,
1215         .link = ecryptfs_link,
1216         .unlink = ecryptfs_unlink,
1217         .symlink = ecryptfs_symlink,
1218         .mkdir = ecryptfs_mkdir,
1219         .rmdir = ecryptfs_rmdir,
1220         .mknod = ecryptfs_mknod,
1221         .rename = ecryptfs_rename,
1222         .permission = ecryptfs_permission,
1223         .setattr = ecryptfs_setattr,
1224         .setxattr = ecryptfs_setxattr,
1225         .getxattr = ecryptfs_getxattr,
1226         .listxattr = ecryptfs_listxattr,
1227         .removexattr = ecryptfs_removexattr
1228 };
1229
1230 const struct inode_operations ecryptfs_main_iops = {
1231         .permission = ecryptfs_permission,
1232         .setattr = ecryptfs_setattr,
1233         .getattr = ecryptfs_getattr,
1234         .setxattr = ecryptfs_setxattr,
1235         .getxattr = ecryptfs_getxattr,
1236         .listxattr = ecryptfs_listxattr,
1237         .removexattr = ecryptfs_removexattr
1238 };