drm/i915: un-EXPORT and make 'intelfb_panic' static
[linux-2.6/mini2440.git] / fs / ecryptfs / inode.c
blob89209f00f9c74ecc752ed944f26ecff6e2f5c974
1 /**
2 * eCryptfs: Linux filesystem encryption layer
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>
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.
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.
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.
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 <asm/unaligned.h>
35 #include "ecryptfs_kernel.h"
37 static struct dentry *lock_parent(struct dentry *dentry)
39 struct dentry *dir;
41 dir = dget_parent(dentry);
42 mutex_lock_nested(&(dir->d_inode->i_mutex), I_MUTEX_PARENT);
43 return dir;
46 static void unlock_dir(struct dentry *dir)
48 mutex_unlock(&dir->d_inode->i_mutex);
49 dput(dir);
52 /**
53 * ecryptfs_create_underlying_file
54 * @lower_dir_inode: inode of the parent in the lower fs of the new file
55 * @lower_dentry: New file's dentry in the lower fs
56 * @ecryptfs_dentry: New file's dentry in ecryptfs
57 * @mode: The mode of the new file
58 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
60 * Creates the file in the lower file system.
62 * Returns zero on success; non-zero on error condition
64 static int
65 ecryptfs_create_underlying_file(struct inode *lower_dir_inode,
66 struct dentry *dentry, int mode,
67 struct nameidata *nd)
69 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
70 struct vfsmount *lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry);
71 struct dentry *dentry_save;
72 struct vfsmount *vfsmount_save;
73 int rc;
75 dentry_save = nd->path.dentry;
76 vfsmount_save = nd->path.mnt;
77 nd->path.dentry = lower_dentry;
78 nd->path.mnt = lower_mnt;
79 rc = vfs_create(lower_dir_inode, lower_dentry, mode, nd);
80 nd->path.dentry = dentry_save;
81 nd->path.mnt = vfsmount_save;
82 return rc;
85 /**
86 * ecryptfs_do_create
87 * @directory_inode: inode of the new file's dentry's parent in ecryptfs
88 * @ecryptfs_dentry: New file's dentry in ecryptfs
89 * @mode: The mode of the new file
90 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
92 * Creates the underlying file and the eCryptfs inode which will link to
93 * it. It will also update the eCryptfs directory inode to mimic the
94 * stat of the lower directory inode.
96 * Returns zero on success; non-zero on error condition
98 static int
99 ecryptfs_do_create(struct inode *directory_inode,
100 struct dentry *ecryptfs_dentry, int mode,
101 struct nameidata *nd)
103 int rc;
104 struct dentry *lower_dentry;
105 struct dentry *lower_dir_dentry;
107 lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
108 lower_dir_dentry = lock_parent(lower_dentry);
109 if (IS_ERR(lower_dir_dentry)) {
110 ecryptfs_printk(KERN_ERR, "Error locking directory of "
111 "dentry\n");
112 rc = PTR_ERR(lower_dir_dentry);
113 goto out;
115 rc = ecryptfs_create_underlying_file(lower_dir_dentry->d_inode,
116 ecryptfs_dentry, mode, nd);
117 if (rc) {
118 printk(KERN_ERR "%s: Failure to create dentry in lower fs; "
119 "rc = [%d]\n", __func__, rc);
120 goto out_lock;
122 rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry,
123 directory_inode->i_sb, 0);
124 if (rc) {
125 ecryptfs_printk(KERN_ERR, "Failure in ecryptfs_interpose\n");
126 goto out_lock;
128 fsstack_copy_attr_times(directory_inode, lower_dir_dentry->d_inode);
129 fsstack_copy_inode_size(directory_inode, lower_dir_dentry->d_inode);
130 out_lock:
131 unlock_dir(lower_dir_dentry);
132 out:
133 return rc;
137 * grow_file
138 * @ecryptfs_dentry: the eCryptfs dentry
140 * This is the code which will grow the file to its correct size.
142 static int grow_file(struct dentry *ecryptfs_dentry)
144 struct inode *ecryptfs_inode = ecryptfs_dentry->d_inode;
145 struct file fake_file;
146 struct ecryptfs_file_info tmp_file_info;
147 char zero_virt[] = { 0x00 };
148 int rc = 0;
150 memset(&fake_file, 0, sizeof(fake_file));
151 fake_file.f_path.dentry = ecryptfs_dentry;
152 memset(&tmp_file_info, 0, sizeof(tmp_file_info));
153 ecryptfs_set_file_private(&fake_file, &tmp_file_info);
154 ecryptfs_set_file_lower(
155 &fake_file,
156 ecryptfs_inode_to_private(ecryptfs_inode)->lower_file);
157 rc = ecryptfs_write(&fake_file, zero_virt, 0, 1);
158 i_size_write(ecryptfs_inode, 0);
159 rc = ecryptfs_write_inode_size_to_metadata(ecryptfs_inode);
160 ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat.flags |=
161 ECRYPTFS_NEW_FILE;
162 return rc;
166 * ecryptfs_initialize_file
168 * Cause the file to be changed from a basic empty file to an ecryptfs
169 * file with a header and first data page.
171 * Returns zero on success
173 static int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry)
175 struct ecryptfs_crypt_stat *crypt_stat =
176 &ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat;
177 int rc = 0;
179 if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) {
180 ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
181 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
182 goto out;
184 crypt_stat->flags |= ECRYPTFS_NEW_FILE;
185 ecryptfs_printk(KERN_DEBUG, "Initializing crypto context\n");
186 rc = ecryptfs_new_file_context(ecryptfs_dentry);
187 if (rc) {
188 ecryptfs_printk(KERN_ERR, "Error creating new file "
189 "context; rc = [%d]\n", rc);
190 goto out;
192 if (!ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->lower_file) {
193 rc = ecryptfs_init_persistent_file(ecryptfs_dentry);
194 if (rc) {
195 printk(KERN_ERR "%s: Error attempting to initialize "
196 "the persistent file for the dentry with name "
197 "[%s]; rc = [%d]\n", __func__,
198 ecryptfs_dentry->d_name.name, rc);
199 goto out;
202 rc = ecryptfs_write_metadata(ecryptfs_dentry);
203 if (rc) {
204 printk(KERN_ERR "Error writing headers; rc = [%d]\n", rc);
205 goto out;
207 rc = grow_file(ecryptfs_dentry);
208 if (rc)
209 printk(KERN_ERR "Error growing file; rc = [%d]\n", rc);
210 out:
211 return rc;
215 * ecryptfs_create
216 * @dir: The inode of the directory in which to create the file.
217 * @dentry: The eCryptfs dentry
218 * @mode: The mode of the new file.
219 * @nd: nameidata
221 * Creates a new file.
223 * Returns zero on success; non-zero on error condition
225 static int
226 ecryptfs_create(struct inode *directory_inode, struct dentry *ecryptfs_dentry,
227 int mode, struct nameidata *nd)
229 int rc;
231 /* ecryptfs_do_create() calls ecryptfs_interpose(), which opens
232 * the crypt_stat->lower_file (persistent file) */
233 rc = ecryptfs_do_create(directory_inode, ecryptfs_dentry, mode, nd);
234 if (unlikely(rc)) {
235 ecryptfs_printk(KERN_WARNING, "Failed to create file in"
236 "lower filesystem\n");
237 goto out;
239 /* At this point, a file exists on "disk"; we need to make sure
240 * that this on disk file is prepared to be an ecryptfs file */
241 rc = ecryptfs_initialize_file(ecryptfs_dentry);
242 out:
243 return rc;
247 * ecryptfs_lookup
248 * @dir: inode
249 * @dentry: The dentry
250 * @nd: nameidata, may be NULL
252 * Find a file on disk. If the file does not exist, then we'll add it to the
253 * dentry cache and continue on to read it from the disk.
255 static struct dentry *ecryptfs_lookup(struct inode *dir, struct dentry *dentry,
256 struct nameidata *nd)
258 int rc = 0;
259 struct dentry *lower_dir_dentry;
260 struct dentry *lower_dentry;
261 struct vfsmount *lower_mnt;
262 char *encoded_name;
263 int encoded_namelen;
264 struct ecryptfs_crypt_stat *crypt_stat = NULL;
265 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
266 char *page_virt = NULL;
267 struct inode *lower_inode;
268 u64 file_size;
270 lower_dir_dentry = ecryptfs_dentry_to_lower(dentry->d_parent);
271 dentry->d_op = &ecryptfs_dops;
272 if ((dentry->d_name.len == 1 && !strcmp(dentry->d_name.name, "."))
273 || (dentry->d_name.len == 2
274 && !strcmp(dentry->d_name.name, ".."))) {
275 d_drop(dentry);
276 goto out;
278 encoded_namelen = ecryptfs_encode_filename(crypt_stat,
279 dentry->d_name.name,
280 dentry->d_name.len,
281 &encoded_name);
282 if (encoded_namelen < 0) {
283 rc = encoded_namelen;
284 d_drop(dentry);
285 goto out;
287 ecryptfs_printk(KERN_DEBUG, "encoded_name = [%s]; encoded_namelen "
288 "= [%d]\n", encoded_name, encoded_namelen);
289 lower_dentry = lookup_one_len(encoded_name, lower_dir_dentry,
290 encoded_namelen - 1);
291 kfree(encoded_name);
292 if (IS_ERR(lower_dentry)) {
293 ecryptfs_printk(KERN_ERR, "ERR from lower_dentry\n");
294 rc = PTR_ERR(lower_dentry);
295 d_drop(dentry);
296 goto out;
298 lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(dentry->d_parent));
299 ecryptfs_printk(KERN_DEBUG, "lower_dentry = [%p]; lower_dentry->"
300 "d_name.name = [%s]\n", lower_dentry,
301 lower_dentry->d_name.name);
302 lower_inode = lower_dentry->d_inode;
303 fsstack_copy_attr_atime(dir, lower_dir_dentry->d_inode);
304 BUG_ON(!atomic_read(&lower_dentry->d_count));
305 ecryptfs_set_dentry_private(dentry,
306 kmem_cache_alloc(ecryptfs_dentry_info_cache,
307 GFP_KERNEL));
308 if (!ecryptfs_dentry_to_private(dentry)) {
309 rc = -ENOMEM;
310 ecryptfs_printk(KERN_ERR, "Out of memory whilst attempting "
311 "to allocate ecryptfs_dentry_info struct\n");
312 goto out_dput;
314 ecryptfs_set_dentry_lower(dentry, lower_dentry);
315 ecryptfs_set_dentry_lower_mnt(dentry, lower_mnt);
316 if (!lower_dentry->d_inode) {
317 /* We want to add because we couldn't find in lower */
318 d_add(dentry, NULL);
319 goto out;
321 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb,
322 ECRYPTFS_INTERPOSE_FLAG_D_ADD);
323 if (rc) {
324 ecryptfs_printk(KERN_ERR, "Error interposing\n");
325 goto out;
327 if (S_ISDIR(lower_inode->i_mode)) {
328 ecryptfs_printk(KERN_DEBUG, "Is a directory; returning\n");
329 goto out;
331 if (S_ISLNK(lower_inode->i_mode)) {
332 ecryptfs_printk(KERN_DEBUG, "Is a symlink; returning\n");
333 goto out;
335 if (special_file(lower_inode->i_mode)) {
336 ecryptfs_printk(KERN_DEBUG, "Is a special file; returning\n");
337 goto out;
339 if (!nd) {
340 ecryptfs_printk(KERN_DEBUG, "We have a NULL nd, just leave"
341 "as we *think* we are about to unlink\n");
342 goto out;
344 /* Released in this function */
345 page_virt = kmem_cache_zalloc(ecryptfs_header_cache_2,
346 GFP_USER);
347 if (!page_virt) {
348 rc = -ENOMEM;
349 ecryptfs_printk(KERN_ERR,
350 "Cannot ecryptfs_kmalloc a page\n");
351 goto out;
353 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
354 if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED))
355 ecryptfs_set_default_sizes(crypt_stat);
356 if (!ecryptfs_inode_to_private(dentry->d_inode)->lower_file) {
357 rc = ecryptfs_init_persistent_file(dentry);
358 if (rc) {
359 printk(KERN_ERR "%s: Error attempting to initialize "
360 "the persistent file for the dentry with name "
361 "[%s]; rc = [%d]\n", __func__,
362 dentry->d_name.name, rc);
363 goto out;
366 rc = ecryptfs_read_and_validate_header_region(page_virt,
367 dentry->d_inode);
368 if (rc) {
369 rc = ecryptfs_read_and_validate_xattr_region(page_virt, dentry);
370 if (rc) {
371 printk(KERN_DEBUG "Valid metadata not found in header "
372 "region or xattr region; treating file as "
373 "unencrypted\n");
374 rc = 0;
375 kmem_cache_free(ecryptfs_header_cache_2, page_virt);
376 goto out;
378 crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
380 mount_crypt_stat = &ecryptfs_superblock_to_private(
381 dentry->d_sb)->mount_crypt_stat;
382 if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) {
383 if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
384 file_size = (crypt_stat->num_header_bytes_at_front
385 + i_size_read(lower_dentry->d_inode));
386 else
387 file_size = i_size_read(lower_dentry->d_inode);
388 } else {
389 file_size = get_unaligned_be64(page_virt);
391 i_size_write(dentry->d_inode, (loff_t)file_size);
392 kmem_cache_free(ecryptfs_header_cache_2, page_virt);
393 goto out;
395 out_dput:
396 dput(lower_dentry);
397 d_drop(dentry);
398 out:
399 return ERR_PTR(rc);
402 static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
403 struct dentry *new_dentry)
405 struct dentry *lower_old_dentry;
406 struct dentry *lower_new_dentry;
407 struct dentry *lower_dir_dentry;
408 u64 file_size_save;
409 int rc;
411 file_size_save = i_size_read(old_dentry->d_inode);
412 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
413 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
414 dget(lower_old_dentry);
415 dget(lower_new_dentry);
416 lower_dir_dentry = lock_parent(lower_new_dentry);
417 rc = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode,
418 lower_new_dentry);
419 if (rc || !lower_new_dentry->d_inode)
420 goto out_lock;
421 rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb, 0);
422 if (rc)
423 goto out_lock;
424 fsstack_copy_attr_times(dir, lower_new_dentry->d_inode);
425 fsstack_copy_inode_size(dir, lower_new_dentry->d_inode);
426 old_dentry->d_inode->i_nlink =
427 ecryptfs_inode_to_lower(old_dentry->d_inode)->i_nlink;
428 i_size_write(new_dentry->d_inode, file_size_save);
429 out_lock:
430 unlock_dir(lower_dir_dentry);
431 dput(lower_new_dentry);
432 dput(lower_old_dentry);
433 d_drop(lower_old_dentry);
434 d_drop(new_dentry);
435 d_drop(old_dentry);
436 return rc;
439 static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
441 int rc = 0;
442 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
443 struct inode *lower_dir_inode = ecryptfs_inode_to_lower(dir);
444 struct dentry *lower_dir_dentry;
446 lower_dir_dentry = lock_parent(lower_dentry);
447 rc = vfs_unlink(lower_dir_inode, lower_dentry);
448 if (rc) {
449 printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc);
450 goto out_unlock;
452 fsstack_copy_attr_times(dir, lower_dir_inode);
453 dentry->d_inode->i_nlink =
454 ecryptfs_inode_to_lower(dentry->d_inode)->i_nlink;
455 dentry->d_inode->i_ctime = dir->i_ctime;
456 d_drop(dentry);
457 out_unlock:
458 unlock_dir(lower_dir_dentry);
459 return rc;
462 static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry,
463 const char *symname)
465 int rc;
466 struct dentry *lower_dentry;
467 struct dentry *lower_dir_dentry;
468 char *encoded_symname;
469 int encoded_symlen;
470 struct ecryptfs_crypt_stat *crypt_stat = NULL;
472 lower_dentry = ecryptfs_dentry_to_lower(dentry);
473 dget(lower_dentry);
474 lower_dir_dentry = lock_parent(lower_dentry);
475 encoded_symlen = ecryptfs_encode_filename(crypt_stat, symname,
476 strlen(symname),
477 &encoded_symname);
478 if (encoded_symlen < 0) {
479 rc = encoded_symlen;
480 goto out_lock;
482 rc = vfs_symlink(lower_dir_dentry->d_inode, lower_dentry,
483 encoded_symname);
484 kfree(encoded_symname);
485 if (rc || !lower_dentry->d_inode)
486 goto out_lock;
487 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
488 if (rc)
489 goto out_lock;
490 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
491 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
492 out_lock:
493 unlock_dir(lower_dir_dentry);
494 dput(lower_dentry);
495 if (!dentry->d_inode)
496 d_drop(dentry);
497 return rc;
500 static int ecryptfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
502 int rc;
503 struct dentry *lower_dentry;
504 struct dentry *lower_dir_dentry;
506 lower_dentry = ecryptfs_dentry_to_lower(dentry);
507 lower_dir_dentry = lock_parent(lower_dentry);
508 rc = vfs_mkdir(lower_dir_dentry->d_inode, lower_dentry, mode);
509 if (rc || !lower_dentry->d_inode)
510 goto out;
511 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
512 if (rc)
513 goto out;
514 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
515 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
516 dir->i_nlink = lower_dir_dentry->d_inode->i_nlink;
517 out:
518 unlock_dir(lower_dir_dentry);
519 if (!dentry->d_inode)
520 d_drop(dentry);
521 return rc;
524 static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
526 struct dentry *lower_dentry;
527 struct dentry *lower_dir_dentry;
528 int rc;
530 lower_dentry = ecryptfs_dentry_to_lower(dentry);
531 dget(dentry);
532 lower_dir_dentry = lock_parent(lower_dentry);
533 dget(lower_dentry);
534 rc = vfs_rmdir(lower_dir_dentry->d_inode, lower_dentry);
535 dput(lower_dentry);
536 if (!rc)
537 d_delete(lower_dentry);
538 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
539 dir->i_nlink = lower_dir_dentry->d_inode->i_nlink;
540 unlock_dir(lower_dir_dentry);
541 if (!rc)
542 d_drop(dentry);
543 dput(dentry);
544 return rc;
547 static int
548 ecryptfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
550 int rc;
551 struct dentry *lower_dentry;
552 struct dentry *lower_dir_dentry;
554 lower_dentry = ecryptfs_dentry_to_lower(dentry);
555 lower_dir_dentry = lock_parent(lower_dentry);
556 rc = vfs_mknod(lower_dir_dentry->d_inode, lower_dentry, mode, dev);
557 if (rc || !lower_dentry->d_inode)
558 goto out;
559 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
560 if (rc)
561 goto out;
562 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
563 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
564 out:
565 unlock_dir(lower_dir_dentry);
566 if (!dentry->d_inode)
567 d_drop(dentry);
568 return rc;
571 static int
572 ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
573 struct inode *new_dir, struct dentry *new_dentry)
575 int rc;
576 struct dentry *lower_old_dentry;
577 struct dentry *lower_new_dentry;
578 struct dentry *lower_old_dir_dentry;
579 struct dentry *lower_new_dir_dentry;
581 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
582 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
583 dget(lower_old_dentry);
584 dget(lower_new_dentry);
585 lower_old_dir_dentry = dget_parent(lower_old_dentry);
586 lower_new_dir_dentry = dget_parent(lower_new_dentry);
587 lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
588 rc = vfs_rename(lower_old_dir_dentry->d_inode, lower_old_dentry,
589 lower_new_dir_dentry->d_inode, lower_new_dentry);
590 if (rc)
591 goto out_lock;
592 fsstack_copy_attr_all(new_dir, lower_new_dir_dentry->d_inode, NULL);
593 if (new_dir != old_dir)
594 fsstack_copy_attr_all(old_dir, lower_old_dir_dentry->d_inode, NULL);
595 out_lock:
596 unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
597 dput(lower_new_dentry->d_parent);
598 dput(lower_old_dentry->d_parent);
599 dput(lower_new_dentry);
600 dput(lower_old_dentry);
601 return rc;
604 static int
605 ecryptfs_readlink(struct dentry *dentry, char __user * buf, int bufsiz)
607 int rc;
608 struct dentry *lower_dentry;
609 char *decoded_name;
610 char *lower_buf;
611 mm_segment_t old_fs;
612 struct ecryptfs_crypt_stat *crypt_stat;
614 lower_dentry = ecryptfs_dentry_to_lower(dentry);
615 if (!lower_dentry->d_inode->i_op ||
616 !lower_dentry->d_inode->i_op->readlink) {
617 rc = -EINVAL;
618 goto out;
620 /* Released in this function */
621 lower_buf = kmalloc(bufsiz, GFP_KERNEL);
622 if (lower_buf == NULL) {
623 ecryptfs_printk(KERN_ERR, "Out of memory\n");
624 rc = -ENOMEM;
625 goto out;
627 old_fs = get_fs();
628 set_fs(get_ds());
629 ecryptfs_printk(KERN_DEBUG, "Calling readlink w/ "
630 "lower_dentry->d_name.name = [%s]\n",
631 lower_dentry->d_name.name);
632 rc = lower_dentry->d_inode->i_op->readlink(lower_dentry,
633 (char __user *)lower_buf,
634 bufsiz);
635 set_fs(old_fs);
636 if (rc >= 0) {
637 crypt_stat = NULL;
638 rc = ecryptfs_decode_filename(crypt_stat, lower_buf, rc,
639 &decoded_name);
640 if (rc == -ENOMEM)
641 goto out_free_lower_buf;
642 if (rc > 0) {
643 ecryptfs_printk(KERN_DEBUG, "Copying [%d] bytes "
644 "to userspace: [%*s]\n", rc,
645 decoded_name);
646 if (copy_to_user(buf, decoded_name, rc))
647 rc = -EFAULT;
649 kfree(decoded_name);
650 fsstack_copy_attr_atime(dentry->d_inode,
651 lower_dentry->d_inode);
653 out_free_lower_buf:
654 kfree(lower_buf);
655 out:
656 return rc;
659 static void *ecryptfs_follow_link(struct dentry *dentry, struct nameidata *nd)
661 char *buf;
662 int len = PAGE_SIZE, rc;
663 mm_segment_t old_fs;
665 /* Released in ecryptfs_put_link(); only release here on error */
666 buf = kmalloc(len, GFP_KERNEL);
667 if (!buf) {
668 rc = -ENOMEM;
669 goto out;
671 old_fs = get_fs();
672 set_fs(get_ds());
673 ecryptfs_printk(KERN_DEBUG, "Calling readlink w/ "
674 "dentry->d_name.name = [%s]\n", dentry->d_name.name);
675 rc = dentry->d_inode->i_op->readlink(dentry, (char __user *)buf, len);
676 buf[rc] = '\0';
677 set_fs(old_fs);
678 if (rc < 0)
679 goto out_free;
680 rc = 0;
681 nd_set_link(nd, buf);
682 goto out;
683 out_free:
684 kfree(buf);
685 out:
686 return ERR_PTR(rc);
689 static void
690 ecryptfs_put_link(struct dentry *dentry, struct nameidata *nd, void *ptr)
692 /* Free the char* */
693 kfree(nd_get_link(nd));
697 * upper_size_to_lower_size
698 * @crypt_stat: Crypt_stat associated with file
699 * @upper_size: Size of the upper file
701 * Calculate the required size of the lower file based on the
702 * specified size of the upper file. This calculation is based on the
703 * number of headers in the underlying file and the extent size.
705 * Returns Calculated size of the lower file.
707 static loff_t
708 upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
709 loff_t upper_size)
711 loff_t lower_size;
713 lower_size = crypt_stat->num_header_bytes_at_front;
714 if (upper_size != 0) {
715 loff_t num_extents;
717 num_extents = upper_size >> crypt_stat->extent_shift;
718 if (upper_size & ~crypt_stat->extent_mask)
719 num_extents++;
720 lower_size += (num_extents * crypt_stat->extent_size);
722 return lower_size;
726 * ecryptfs_truncate
727 * @dentry: The ecryptfs layer dentry
728 * @new_length: The length to expand the file to
730 * Function to handle truncations modifying the size of the file. Note
731 * that the file sizes are interpolated. When expanding, we are simply
732 * writing strings of 0's out. When truncating, we need to modify the
733 * underlying file size according to the page index interpolations.
735 * Returns zero on success; non-zero otherwise
737 int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
739 int rc = 0;
740 struct inode *inode = dentry->d_inode;
741 struct dentry *lower_dentry;
742 struct file fake_ecryptfs_file;
743 struct ecryptfs_crypt_stat *crypt_stat;
744 loff_t i_size = i_size_read(inode);
745 loff_t lower_size_before_truncate;
746 loff_t lower_size_after_truncate;
748 if (unlikely((new_length == i_size)))
749 goto out;
750 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
751 /* Set up a fake ecryptfs file, this is used to interface with
752 * the file in the underlying filesystem so that the
753 * truncation has an effect there as well. */
754 memset(&fake_ecryptfs_file, 0, sizeof(fake_ecryptfs_file));
755 fake_ecryptfs_file.f_path.dentry = dentry;
756 /* Released at out_free: label */
757 ecryptfs_set_file_private(&fake_ecryptfs_file,
758 kmem_cache_alloc(ecryptfs_file_info_cache,
759 GFP_KERNEL));
760 if (unlikely(!ecryptfs_file_to_private(&fake_ecryptfs_file))) {
761 rc = -ENOMEM;
762 goto out;
764 lower_dentry = ecryptfs_dentry_to_lower(dentry);
765 ecryptfs_set_file_lower(
766 &fake_ecryptfs_file,
767 ecryptfs_inode_to_private(dentry->d_inode)->lower_file);
768 /* Switch on growing or shrinking file */
769 if (new_length > i_size) {
770 char zero[] = { 0x00 };
772 /* Write a single 0 at the last position of the file;
773 * this triggers code that will fill in 0's throughout
774 * the intermediate portion of the previous end of the
775 * file and the new and of the file */
776 rc = ecryptfs_write(&fake_ecryptfs_file, zero,
777 (new_length - 1), 1);
778 } else { /* new_length < i_size_read(inode) */
779 /* We're chopping off all the pages down do the page
780 * in which new_length is located. Fill in the end of
781 * that page from (new_length & ~PAGE_CACHE_MASK) to
782 * PAGE_CACHE_SIZE with zeros. */
783 size_t num_zeros = (PAGE_CACHE_SIZE
784 - (new_length & ~PAGE_CACHE_MASK));
786 if (num_zeros) {
787 char *zeros_virt;
789 zeros_virt = kzalloc(num_zeros, GFP_KERNEL);
790 if (!zeros_virt) {
791 rc = -ENOMEM;
792 goto out_free;
794 rc = ecryptfs_write(&fake_ecryptfs_file, zeros_virt,
795 new_length, num_zeros);
796 kfree(zeros_virt);
797 if (rc) {
798 printk(KERN_ERR "Error attempting to zero out "
799 "the remainder of the end page on "
800 "reducing truncate; rc = [%d]\n", rc);
801 goto out_free;
804 vmtruncate(inode, new_length);
805 rc = ecryptfs_write_inode_size_to_metadata(inode);
806 if (rc) {
807 printk(KERN_ERR "Problem with "
808 "ecryptfs_write_inode_size_to_metadata; "
809 "rc = [%d]\n", rc);
810 goto out_free;
812 /* We are reducing the size of the ecryptfs file, and need to
813 * know if we need to reduce the size of the lower file. */
814 lower_size_before_truncate =
815 upper_size_to_lower_size(crypt_stat, i_size);
816 lower_size_after_truncate =
817 upper_size_to_lower_size(crypt_stat, new_length);
818 if (lower_size_after_truncate < lower_size_before_truncate)
819 vmtruncate(lower_dentry->d_inode,
820 lower_size_after_truncate);
822 out_free:
823 if (ecryptfs_file_to_private(&fake_ecryptfs_file))
824 kmem_cache_free(ecryptfs_file_info_cache,
825 ecryptfs_file_to_private(&fake_ecryptfs_file));
826 out:
827 return rc;
830 static int
831 ecryptfs_permission(struct inode *inode, int mask)
833 return inode_permission(ecryptfs_inode_to_lower(inode), mask);
837 * ecryptfs_setattr
838 * @dentry: dentry handle to the inode to modify
839 * @ia: Structure with flags of what to change and values
841 * Updates the metadata of an inode. If the update is to the size
842 * i.e. truncation, then ecryptfs_truncate will handle the size modification
843 * of both the ecryptfs inode and the lower inode.
845 * All other metadata changes will be passed right to the lower filesystem,
846 * and we will just update our inode to look like the lower.
848 static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
850 int rc = 0;
851 struct dentry *lower_dentry;
852 struct inode *inode;
853 struct inode *lower_inode;
854 struct ecryptfs_crypt_stat *crypt_stat;
856 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
857 if (!(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED))
858 ecryptfs_init_crypt_stat(crypt_stat);
859 inode = dentry->d_inode;
860 lower_inode = ecryptfs_inode_to_lower(inode);
861 lower_dentry = ecryptfs_dentry_to_lower(dentry);
862 mutex_lock(&crypt_stat->cs_mutex);
863 if (S_ISDIR(dentry->d_inode->i_mode))
864 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
865 else if (S_ISREG(dentry->d_inode->i_mode)
866 && (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
867 || !(crypt_stat->flags & ECRYPTFS_KEY_VALID))) {
868 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
870 mount_crypt_stat = &ecryptfs_superblock_to_private(
871 dentry->d_sb)->mount_crypt_stat;
872 rc = ecryptfs_read_metadata(dentry);
873 if (rc) {
874 if (!(mount_crypt_stat->flags
875 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
876 rc = -EIO;
877 printk(KERN_WARNING "Either the lower file "
878 "is not in a valid eCryptfs format, "
879 "or the key could not be retrieved. "
880 "Plaintext passthrough mode is not "
881 "enabled; returning -EIO\n");
882 mutex_unlock(&crypt_stat->cs_mutex);
883 goto out;
885 rc = 0;
886 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
887 mutex_unlock(&crypt_stat->cs_mutex);
888 goto out;
891 mutex_unlock(&crypt_stat->cs_mutex);
892 if (ia->ia_valid & ATTR_SIZE) {
893 ecryptfs_printk(KERN_DEBUG,
894 "ia->ia_valid = [0x%x] ATTR_SIZE" " = [0x%x]\n",
895 ia->ia_valid, ATTR_SIZE);
896 rc = ecryptfs_truncate(dentry, ia->ia_size);
897 /* ecryptfs_truncate handles resizing of the lower file */
898 ia->ia_valid &= ~ATTR_SIZE;
899 ecryptfs_printk(KERN_DEBUG, "ia->ia_valid = [%x]\n",
900 ia->ia_valid);
901 if (rc < 0)
902 goto out;
906 * mode change is for clearing setuid/setgid bits. Allow lower fs
907 * to interpret this in its own way.
909 if (ia->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
910 ia->ia_valid &= ~ATTR_MODE;
912 mutex_lock(&lower_dentry->d_inode->i_mutex);
913 rc = notify_change(lower_dentry, ia);
914 mutex_unlock(&lower_dentry->d_inode->i_mutex);
915 out:
916 fsstack_copy_attr_all(inode, lower_inode, NULL);
917 return rc;
921 ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value,
922 size_t size, int flags)
924 int rc = 0;
925 struct dentry *lower_dentry;
927 lower_dentry = ecryptfs_dentry_to_lower(dentry);
928 if (!lower_dentry->d_inode->i_op->setxattr) {
929 rc = -ENOSYS;
930 goto out;
932 mutex_lock(&lower_dentry->d_inode->i_mutex);
933 rc = lower_dentry->d_inode->i_op->setxattr(lower_dentry, name, value,
934 size, flags);
935 mutex_unlock(&lower_dentry->d_inode->i_mutex);
936 out:
937 return rc;
940 ssize_t
941 ecryptfs_getxattr_lower(struct dentry *lower_dentry, const char *name,
942 void *value, size_t size)
944 int rc = 0;
946 if (!lower_dentry->d_inode->i_op->getxattr) {
947 rc = -ENOSYS;
948 goto out;
950 mutex_lock(&lower_dentry->d_inode->i_mutex);
951 rc = lower_dentry->d_inode->i_op->getxattr(lower_dentry, name, value,
952 size);
953 mutex_unlock(&lower_dentry->d_inode->i_mutex);
954 out:
955 return rc;
958 static ssize_t
959 ecryptfs_getxattr(struct dentry *dentry, const char *name, void *value,
960 size_t size)
962 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry), name,
963 value, size);
966 static ssize_t
967 ecryptfs_listxattr(struct dentry *dentry, char *list, size_t size)
969 int rc = 0;
970 struct dentry *lower_dentry;
972 lower_dentry = ecryptfs_dentry_to_lower(dentry);
973 if (!lower_dentry->d_inode->i_op->listxattr) {
974 rc = -ENOSYS;
975 goto out;
977 mutex_lock(&lower_dentry->d_inode->i_mutex);
978 rc = lower_dentry->d_inode->i_op->listxattr(lower_dentry, list, size);
979 mutex_unlock(&lower_dentry->d_inode->i_mutex);
980 out:
981 return rc;
984 static int ecryptfs_removexattr(struct dentry *dentry, const char *name)
986 int rc = 0;
987 struct dentry *lower_dentry;
989 lower_dentry = ecryptfs_dentry_to_lower(dentry);
990 if (!lower_dentry->d_inode->i_op->removexattr) {
991 rc = -ENOSYS;
992 goto out;
994 mutex_lock(&lower_dentry->d_inode->i_mutex);
995 rc = lower_dentry->d_inode->i_op->removexattr(lower_dentry, name);
996 mutex_unlock(&lower_dentry->d_inode->i_mutex);
997 out:
998 return rc;
1001 int ecryptfs_inode_test(struct inode *inode, void *candidate_lower_inode)
1003 if ((ecryptfs_inode_to_lower(inode)
1004 == (struct inode *)candidate_lower_inode))
1005 return 1;
1006 else
1007 return 0;
1010 int ecryptfs_inode_set(struct inode *inode, void *lower_inode)
1012 ecryptfs_init_inode(inode, (struct inode *)lower_inode);
1013 return 0;
1016 const struct inode_operations ecryptfs_symlink_iops = {
1017 .readlink = ecryptfs_readlink,
1018 .follow_link = ecryptfs_follow_link,
1019 .put_link = ecryptfs_put_link,
1020 .permission = ecryptfs_permission,
1021 .setattr = ecryptfs_setattr,
1022 .setxattr = ecryptfs_setxattr,
1023 .getxattr = ecryptfs_getxattr,
1024 .listxattr = ecryptfs_listxattr,
1025 .removexattr = ecryptfs_removexattr
1028 const struct inode_operations ecryptfs_dir_iops = {
1029 .create = ecryptfs_create,
1030 .lookup = ecryptfs_lookup,
1031 .link = ecryptfs_link,
1032 .unlink = ecryptfs_unlink,
1033 .symlink = ecryptfs_symlink,
1034 .mkdir = ecryptfs_mkdir,
1035 .rmdir = ecryptfs_rmdir,
1036 .mknod = ecryptfs_mknod,
1037 .rename = ecryptfs_rename,
1038 .permission = ecryptfs_permission,
1039 .setattr = ecryptfs_setattr,
1040 .setxattr = ecryptfs_setxattr,
1041 .getxattr = ecryptfs_getxattr,
1042 .listxattr = ecryptfs_listxattr,
1043 .removexattr = ecryptfs_removexattr
1046 const struct inode_operations ecryptfs_main_iops = {
1047 .permission = ecryptfs_permission,
1048 .setattr = ecryptfs_setattr,
1049 .setxattr = ecryptfs_setxattr,
1050 .getxattr = ecryptfs_getxattr,
1051 .listxattr = ecryptfs_listxattr,
1052 .removexattr = ecryptfs_removexattr