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-rw-r--r--fs/ecryptfs/inode.c1079
1 files changed, 1079 insertions, 0 deletions
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
new file mode 100644
index 000000000000..efdd2b7b62d7
--- /dev/null
+++ b/fs/ecryptfs/inode.c
@@ -0,0 +1,1079 @@
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) 2004-2006 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 "ecryptfs_kernel.h"
34
35static struct dentry *lock_parent(struct dentry *dentry)
36{
37 struct dentry *dir;
38
39 dir = dget(dentry->d_parent);
40 mutex_lock(&(dir->d_inode->i_mutex));
41 return dir;
42}
43
44static void unlock_parent(struct dentry *dentry)
45{
46 mutex_unlock(&(dentry->d_parent->d_inode->i_mutex));
47 dput(dentry->d_parent);
48}
49
50static void unlock_dir(struct dentry *dir)
51{
52 mutex_unlock(&dir->d_inode->i_mutex);
53 dput(dir);
54}
55
56void ecryptfs_copy_inode_size(struct inode *dst, const struct inode *src)
57{
58 i_size_write(dst, i_size_read((struct inode *)src));
59 dst->i_blocks = src->i_blocks;
60}
61
62void ecryptfs_copy_attr_atime(struct inode *dest, const struct inode *src)
63{
64 dest->i_atime = src->i_atime;
65}
66
67static void ecryptfs_copy_attr_times(struct inode *dest,
68 const struct inode *src)
69{
70 dest->i_atime = src->i_atime;
71 dest->i_mtime = src->i_mtime;
72 dest->i_ctime = src->i_ctime;
73}
74
75static void ecryptfs_copy_attr_timesizes(struct inode *dest,
76 const struct inode *src)
77{
78 dest->i_atime = src->i_atime;
79 dest->i_mtime = src->i_mtime;
80 dest->i_ctime = src->i_ctime;
81 ecryptfs_copy_inode_size(dest, src);
82}
83
84void ecryptfs_copy_attr_all(struct inode *dest, const struct inode *src)
85{
86 dest->i_mode = src->i_mode;
87 dest->i_nlink = src->i_nlink;
88 dest->i_uid = src->i_uid;
89 dest->i_gid = src->i_gid;
90 dest->i_rdev = src->i_rdev;
91 dest->i_atime = src->i_atime;
92 dest->i_mtime = src->i_mtime;
93 dest->i_ctime = src->i_ctime;
94 dest->i_blkbits = src->i_blkbits;
95 dest->i_flags = src->i_flags;
96}
97
98/**
99 * ecryptfs_create_underlying_file
100 * @lower_dir_inode: inode of the parent in the lower fs of the new file
101 * @lower_dentry: New file's dentry in the lower fs
102 * @ecryptfs_dentry: New file's dentry in ecryptfs
103 * @mode: The mode of the new file
104 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
105 *
106 * Creates the file in the lower file system.
107 *
108 * Returns zero on success; non-zero on error condition
109 */
110static int
111ecryptfs_create_underlying_file(struct inode *lower_dir_inode,
112 struct dentry *dentry, int mode,
113 struct nameidata *nd)
114{
115 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
116 struct vfsmount *lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry);
117 struct dentry *dentry_save;
118 struct vfsmount *vfsmount_save;
119 int rc;
120
121 dentry_save = nd->dentry;
122 vfsmount_save = nd->mnt;
123 nd->dentry = lower_dentry;
124 nd->mnt = lower_mnt;
125 rc = vfs_create(lower_dir_inode, lower_dentry, mode, nd);
126 nd->dentry = dentry_save;
127 nd->mnt = vfsmount_save;
128 return rc;
129}
130
131/**
132 * ecryptfs_do_create
133 * @directory_inode: inode of the new file's dentry's parent in ecryptfs
134 * @ecryptfs_dentry: New file's dentry in ecryptfs
135 * @mode: The mode of the new file
136 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
137 *
138 * Creates the underlying file and the eCryptfs inode which will link to
139 * it. It will also update the eCryptfs directory inode to mimic the
140 * stat of the lower directory inode.
141 *
142 * Returns zero on success; non-zero on error condition
143 */
144static int
145ecryptfs_do_create(struct inode *directory_inode,
146 struct dentry *ecryptfs_dentry, int mode,
147 struct nameidata *nd)
148{
149 int rc;
150 struct dentry *lower_dentry;
151 struct dentry *lower_dir_dentry;
152
153 lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
154 lower_dir_dentry = lock_parent(lower_dentry);
155 if (unlikely(IS_ERR(lower_dir_dentry))) {
156 ecryptfs_printk(KERN_ERR, "Error locking directory of "
157 "dentry\n");
158 rc = PTR_ERR(lower_dir_dentry);
159 goto out;
160 }
161 rc = ecryptfs_create_underlying_file(lower_dir_dentry->d_inode,
162 ecryptfs_dentry, mode, nd);
163 if (unlikely(rc)) {
164 ecryptfs_printk(KERN_ERR,
165 "Failure to create underlying file\n");
166 goto out_lock;
167 }
168 rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry,
169 directory_inode->i_sb, 0);
170 if (rc) {
171 ecryptfs_printk(KERN_ERR, "Failure in ecryptfs_interpose\n");
172 goto out_lock;
173 }
174 ecryptfs_copy_attr_timesizes(directory_inode,
175 lower_dir_dentry->d_inode);
176out_lock:
177 unlock_dir(lower_dir_dentry);
178out:
179 return rc;
180}
181
182/**
183 * grow_file
184 * @ecryptfs_dentry: the ecryptfs dentry
185 * @lower_file: The lower file
186 * @inode: The ecryptfs inode
187 * @lower_inode: The lower inode
188 *
189 * This is the code which will grow the file to its correct size.
190 */
191static int grow_file(struct dentry *ecryptfs_dentry, struct file *lower_file,
192 struct inode *inode, struct inode *lower_inode)
193{
194 int rc = 0;
195 struct file fake_file;
196 struct ecryptfs_file_info tmp_file_info;
197
198 memset(&fake_file, 0, sizeof(fake_file));
199 fake_file.f_dentry = ecryptfs_dentry;
200 memset(&tmp_file_info, 0, sizeof(tmp_file_info));
201 ecryptfs_set_file_private(&fake_file, &tmp_file_info);
202 ecryptfs_set_file_lower(&fake_file, lower_file);
203 rc = ecryptfs_fill_zeros(&fake_file, 1);
204 if (rc) {
205 ECRYPTFS_SET_FLAG(
206 ecryptfs_inode_to_private(inode)->crypt_stat.flags,
207 ECRYPTFS_SECURITY_WARNING);
208 ecryptfs_printk(KERN_WARNING, "Error attempting to fill zeros "
209 "in file; rc = [%d]\n", rc);
210 goto out;
211 }
212 i_size_write(inode, 0);
213 ecryptfs_write_inode_size_to_header(lower_file, lower_inode, inode);
214 ECRYPTFS_SET_FLAG(ecryptfs_inode_to_private(inode)->crypt_stat.flags,
215 ECRYPTFS_NEW_FILE);
216out:
217 return rc;
218}
219
220/**
221 * ecryptfs_initialize_file
222 *
223 * Cause the file to be changed from a basic empty file to an ecryptfs
224 * file with a header and first data page.
225 *
226 * Returns zero on success
227 */
228static int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry)
229{
230 int rc = 0;
231 int lower_flags;
232 struct ecryptfs_crypt_stat *crypt_stat;
233 struct dentry *lower_dentry;
234 struct dentry *tlower_dentry = NULL;
235 struct file *lower_file;
236 struct inode *inode, *lower_inode;
237 struct vfsmount *lower_mnt;
238
239 lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
240 ecryptfs_printk(KERN_DEBUG, "lower_dentry->d_name.name = [%s]\n",
241 lower_dentry->d_name.name);
242 inode = ecryptfs_dentry->d_inode;
243 crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
244 tlower_dentry = dget(lower_dentry);
245 if (!tlower_dentry) {
246 rc = -ENOMEM;
247 ecryptfs_printk(KERN_ERR, "Error dget'ing lower_dentry\n");
248 goto out;
249 }
250 lower_flags = ((O_CREAT | O_WRONLY | O_TRUNC) & O_ACCMODE) | O_RDWR;
251#if BITS_PER_LONG != 32
252 lower_flags |= O_LARGEFILE;
253#endif
254 lower_mnt = ecryptfs_dentry_to_lower_mnt(ecryptfs_dentry);
255 mntget(lower_mnt);
256 /* Corresponding fput() at end of this function */
257 lower_file = dentry_open(tlower_dentry, lower_mnt, lower_flags);
258 if (IS_ERR(lower_file)) {
259 rc = PTR_ERR(lower_file);
260 ecryptfs_printk(KERN_ERR,
261 "Error opening dentry; rc = [%i]\n", rc);
262 goto out;
263 }
264 /* fput(lower_file) should handle the puts if we do this */
265 lower_file->f_dentry = tlower_dentry;
266 lower_file->f_vfsmnt = lower_mnt;
267 lower_inode = tlower_dentry->d_inode;
268 if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) {
269 ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
270 ECRYPTFS_CLEAR_FLAG(crypt_stat->flags, ECRYPTFS_ENCRYPTED);
271 goto out_fput;
272 }
273 ECRYPTFS_SET_FLAG(crypt_stat->flags, ECRYPTFS_NEW_FILE);
274 ecryptfs_printk(KERN_DEBUG, "Initializing crypto context\n");
275 rc = ecryptfs_new_file_context(ecryptfs_dentry);
276 if (rc) {
277 ecryptfs_printk(KERN_DEBUG, "Error creating new file "
278 "context\n");
279 goto out_fput;
280 }
281 rc = ecryptfs_write_headers(ecryptfs_dentry, lower_file);
282 if (rc) {
283 ecryptfs_printk(KERN_DEBUG, "Error writing headers\n");
284 goto out_fput;
285 }
286 rc = grow_file(ecryptfs_dentry, lower_file, inode, lower_inode);
287out_fput:
288 fput(lower_file);
289out:
290 return rc;
291}
292
293/**
294 * ecryptfs_create
295 * @dir: The inode of the directory in which to create the file.
296 * @dentry: The eCryptfs dentry
297 * @mode: The mode of the new file.
298 * @nd: nameidata
299 *
300 * Creates a new file.
301 *
302 * Returns zero on success; non-zero on error condition
303 */
304static int
305ecryptfs_create(struct inode *directory_inode, struct dentry *ecryptfs_dentry,
306 int mode, struct nameidata *nd)
307{
308 int rc;
309
310 rc = ecryptfs_do_create(directory_inode, ecryptfs_dentry, mode, nd);
311 if (unlikely(rc)) {
312 ecryptfs_printk(KERN_WARNING, "Failed to create file in"
313 "lower filesystem\n");
314 goto out;
315 }
316 /* At this point, a file exists on "disk"; we need to make sure
317 * that this on disk file is prepared to be an ecryptfs file */
318 rc = ecryptfs_initialize_file(ecryptfs_dentry);
319out:
320 return rc;
321}
322
323/**
324 * ecryptfs_lookup
325 * @dir: inode
326 * @dentry: The dentry
327 * @nd: nameidata, may be NULL
328 *
329 * Find a file on disk. If the file does not exist, then we'll add it to the
330 * dentry cache and continue on to read it from the disk.
331 */
332static struct dentry *ecryptfs_lookup(struct inode *dir, struct dentry *dentry,
333 struct nameidata *nd)
334{
335 int rc = 0;
336 struct dentry *lower_dir_dentry;
337 struct dentry *lower_dentry;
338 struct vfsmount *lower_mnt;
339 struct dentry *tlower_dentry = NULL;
340 char *encoded_name;
341 unsigned int encoded_namelen;
342 struct ecryptfs_crypt_stat *crypt_stat = NULL;
343 char *page_virt = NULL;
344 struct inode *lower_inode;
345 u64 file_size;
346
347 lower_dir_dentry = ecryptfs_dentry_to_lower(dentry->d_parent);
348 dentry->d_op = &ecryptfs_dops;
349 if ((dentry->d_name.len == 1 && !strcmp(dentry->d_name.name, "."))
350 || (dentry->d_name.len == 2 && !strcmp(dentry->d_name.name, "..")))
351 goto out_drop;
352 encoded_namelen = ecryptfs_encode_filename(crypt_stat,
353 dentry->d_name.name,
354 dentry->d_name.len,
355 &encoded_name);
356 if (encoded_namelen < 0) {
357 rc = encoded_namelen;
358 goto out_drop;
359 }
360 ecryptfs_printk(KERN_DEBUG, "encoded_name = [%s]; encoded_namelen "
361 "= [%d]\n", encoded_name, encoded_namelen);
362 lower_dentry = lookup_one_len(encoded_name, lower_dir_dentry,
363 encoded_namelen - 1);
364 kfree(encoded_name);
365 lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(dentry->d_parent));
366 if (IS_ERR(lower_dentry)) {
367 ecryptfs_printk(KERN_ERR, "ERR from lower_dentry\n");
368 rc = PTR_ERR(lower_dentry);
369 goto out_drop;
370 }
371 ecryptfs_printk(KERN_DEBUG, "lower_dentry = [%p]; lower_dentry->"
372 "d_name.name = [%s]\n", lower_dentry,
373 lower_dentry->d_name.name);
374 lower_inode = lower_dentry->d_inode;
375 ecryptfs_copy_attr_atime(dir, lower_dir_dentry->d_inode);
376 BUG_ON(!atomic_read(&lower_dentry->d_count));
377 ecryptfs_set_dentry_private(dentry,
378 kmem_cache_alloc(ecryptfs_dentry_info_cache,
379 SLAB_KERNEL));
380 if (!ecryptfs_dentry_to_private(dentry)) {
381 rc = -ENOMEM;
382 ecryptfs_printk(KERN_ERR, "Out of memory whilst attempting "
383 "to allocate ecryptfs_dentry_info struct\n");
384 goto out_dput;
385 }
386 ecryptfs_set_dentry_lower(dentry, lower_dentry);
387 ecryptfs_set_dentry_lower_mnt(dentry, lower_mnt);
388 if (!lower_dentry->d_inode) {
389 /* We want to add because we couldn't find in lower */
390 d_add(dentry, NULL);
391 goto out;
392 }
393 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 1);
394 if (rc) {
395 ecryptfs_printk(KERN_ERR, "Error interposing\n");
396 goto out_dput;
397 }
398 if (S_ISDIR(lower_inode->i_mode)) {
399 ecryptfs_printk(KERN_DEBUG, "Is a directory; returning\n");
400 goto out;
401 }
402 if (S_ISLNK(lower_inode->i_mode)) {
403 ecryptfs_printk(KERN_DEBUG, "Is a symlink; returning\n");
404 goto out;
405 }
406 if (!nd) {
407 ecryptfs_printk(KERN_DEBUG, "We have a NULL nd, just leave"
408 "as we *think* we are about to unlink\n");
409 goto out;
410 }
411 tlower_dentry = dget(lower_dentry);
412 if (!tlower_dentry || IS_ERR(tlower_dentry)) {
413 rc = -ENOMEM;
414 ecryptfs_printk(KERN_ERR, "Cannot dget lower_dentry\n");
415 goto out_dput;
416 }
417 /* Released in this function */
418 page_virt =
419 (char *)kmem_cache_alloc(ecryptfs_header_cache_2,
420 SLAB_USER);
421 if (!page_virt) {
422 rc = -ENOMEM;
423 ecryptfs_printk(KERN_ERR,
424 "Cannot ecryptfs_kmalloc a page\n");
425 goto out_dput;
426 }
427 memset(page_virt, 0, PAGE_CACHE_SIZE);
428 rc = ecryptfs_read_header_region(page_virt, tlower_dentry, nd->mnt);
429 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
430 if (!ECRYPTFS_CHECK_FLAG(crypt_stat->flags, ECRYPTFS_POLICY_APPLIED))
431 ecryptfs_set_default_sizes(crypt_stat);
432 if (rc) {
433 rc = 0;
434 ecryptfs_printk(KERN_WARNING, "Error reading header region;"
435 " assuming unencrypted\n");
436 } else {
437 if (!contains_ecryptfs_marker(page_virt
438 + ECRYPTFS_FILE_SIZE_BYTES)) {
439 kmem_cache_free(ecryptfs_header_cache_2, page_virt);
440 goto out;
441 }
442 memcpy(&file_size, page_virt, sizeof(file_size));
443 file_size = be64_to_cpu(file_size);
444 i_size_write(dentry->d_inode, (loff_t)file_size);
445 }
446 kmem_cache_free(ecryptfs_header_cache_2, page_virt);
447 goto out;
448
449out_dput:
450 dput(lower_dentry);
451 if (tlower_dentry)
452 dput(tlower_dentry);
453out_drop:
454 d_drop(dentry);
455out:
456 return ERR_PTR(rc);
457}
458
459static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
460 struct dentry *new_dentry)
461{
462 struct dentry *lower_old_dentry;
463 struct dentry *lower_new_dentry;
464 struct dentry *lower_dir_dentry;
465 u64 file_size_save;
466 int rc;
467
468 file_size_save = i_size_read(old_dentry->d_inode);
469 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
470 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
471 dget(lower_old_dentry);
472 dget(lower_new_dentry);
473 lower_dir_dentry = lock_parent(lower_new_dentry);
474 rc = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode,
475 lower_new_dentry);
476 if (rc || !lower_new_dentry->d_inode)
477 goto out_lock;
478 rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb, 0);
479 if (rc)
480 goto out_lock;
481 ecryptfs_copy_attr_timesizes(dir, lower_new_dentry->d_inode);
482 old_dentry->d_inode->i_nlink =
483 ecryptfs_inode_to_lower(old_dentry->d_inode)->i_nlink;
484 i_size_write(new_dentry->d_inode, file_size_save);
485out_lock:
486 unlock_dir(lower_dir_dentry);
487 dput(lower_new_dentry);
488 dput(lower_old_dentry);
489 if (!new_dentry->d_inode)
490 d_drop(new_dentry);
491 return rc;
492}
493
494static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
495{
496 int rc = 0;
497 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
498 struct inode *lower_dir_inode = ecryptfs_inode_to_lower(dir);
499
500 lock_parent(lower_dentry);
501 rc = vfs_unlink(lower_dir_inode, lower_dentry);
502 if (rc) {
503 ecryptfs_printk(KERN_ERR, "Error in vfs_unlink\n");
504 goto out_unlock;
505 }
506 ecryptfs_copy_attr_times(dir, lower_dir_inode);
507 dentry->d_inode->i_nlink =
508 ecryptfs_inode_to_lower(dentry->d_inode)->i_nlink;
509 dentry->d_inode->i_ctime = dir->i_ctime;
510out_unlock:
511 unlock_parent(lower_dentry);
512 return rc;
513}
514
515static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry,
516 const char *symname)
517{
518 int rc;
519 struct dentry *lower_dentry;
520 struct dentry *lower_dir_dentry;
521 umode_t mode;
522 char *encoded_symname;
523 unsigned int encoded_symlen;
524 struct ecryptfs_crypt_stat *crypt_stat = NULL;
525
526 lower_dentry = ecryptfs_dentry_to_lower(dentry);
527 dget(lower_dentry);
528 lower_dir_dentry = lock_parent(lower_dentry);
529 mode = S_IALLUGO;
530 encoded_symlen = ecryptfs_encode_filename(crypt_stat, symname,
531 strlen(symname),
532 &encoded_symname);
533 if (encoded_symlen < 0) {
534 rc = encoded_symlen;
535 goto out_lock;
536 }
537 rc = vfs_symlink(lower_dir_dentry->d_inode, lower_dentry,
538 encoded_symname, mode);
539 kfree(encoded_symname);
540 if (rc || !lower_dentry->d_inode)
541 goto out_lock;
542 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
543 if (rc)
544 goto out_lock;
545 ecryptfs_copy_attr_timesizes(dir, lower_dir_dentry->d_inode);
546out_lock:
547 unlock_dir(lower_dir_dentry);
548 dput(lower_dentry);
549 if (!dentry->d_inode)
550 d_drop(dentry);
551 return rc;
552}
553
554static int ecryptfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
555{
556 int rc;
557 struct dentry *lower_dentry;
558 struct dentry *lower_dir_dentry;
559
560 lower_dentry = ecryptfs_dentry_to_lower(dentry);
561 lower_dir_dentry = lock_parent(lower_dentry);
562 rc = vfs_mkdir(lower_dir_dentry->d_inode, lower_dentry, mode);
563 if (rc || !lower_dentry->d_inode)
564 goto out;
565 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
566 if (rc)
567 goto out;
568 ecryptfs_copy_attr_timesizes(dir, lower_dir_dentry->d_inode);
569 dir->i_nlink = lower_dir_dentry->d_inode->i_nlink;
570out:
571 unlock_dir(lower_dir_dentry);
572 if (!dentry->d_inode)
573 d_drop(dentry);
574 return rc;
575}
576
577static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
578{
579 int rc = 0;
580 struct dentry *tdentry = NULL;
581 struct dentry *lower_dentry;
582 struct dentry *tlower_dentry = NULL;
583 struct dentry *lower_dir_dentry;
584
585 lower_dentry = ecryptfs_dentry_to_lower(dentry);
586 if (!(tdentry = dget(dentry))) {
587 rc = -EINVAL;
588 ecryptfs_printk(KERN_ERR, "Error dget'ing dentry [%p]\n",
589 dentry);
590 goto out;
591 }
592 lower_dir_dentry = lock_parent(lower_dentry);
593 if (!(tlower_dentry = dget(lower_dentry))) {
594 rc = -EINVAL;
595 ecryptfs_printk(KERN_ERR, "Error dget'ing lower_dentry "
596 "[%p]\n", lower_dentry);
597 goto out;
598 }
599 rc = vfs_rmdir(lower_dir_dentry->d_inode, lower_dentry);
600 if (!rc) {
601 d_delete(tlower_dentry);
602 tlower_dentry = NULL;
603 }
604 ecryptfs_copy_attr_times(dir, lower_dir_dentry->d_inode);
605 dir->i_nlink = lower_dir_dentry->d_inode->i_nlink;
606 unlock_dir(lower_dir_dentry);
607 if (!rc)
608 d_drop(dentry);
609out:
610 if (tdentry)
611 dput(tdentry);
612 if (tlower_dentry)
613 dput(tlower_dentry);
614 return rc;
615}
616
617static int
618ecryptfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
619{
620 int rc;
621 struct dentry *lower_dentry;
622 struct dentry *lower_dir_dentry;
623
624 lower_dentry = ecryptfs_dentry_to_lower(dentry);
625 lower_dir_dentry = lock_parent(lower_dentry);
626 rc = vfs_mknod(lower_dir_dentry->d_inode, lower_dentry, mode, dev);
627 if (rc || !lower_dentry->d_inode)
628 goto out;
629 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
630 if (rc)
631 goto out;
632 ecryptfs_copy_attr_timesizes(dir, lower_dir_dentry->d_inode);
633out:
634 unlock_dir(lower_dir_dentry);
635 if (!dentry->d_inode)
636 d_drop(dentry);
637 return rc;
638}
639
640static int
641ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
642 struct inode *new_dir, struct dentry *new_dentry)
643{
644 int rc;
645 struct dentry *lower_old_dentry;
646 struct dentry *lower_new_dentry;
647 struct dentry *lower_old_dir_dentry;
648 struct dentry *lower_new_dir_dentry;
649
650 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
651 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
652 dget(lower_old_dentry);
653 dget(lower_new_dentry);
654 lower_old_dir_dentry = dget_parent(lower_old_dentry);
655 lower_new_dir_dentry = dget_parent(lower_new_dentry);
656 lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
657 rc = vfs_rename(lower_old_dir_dentry->d_inode, lower_old_dentry,
658 lower_new_dir_dentry->d_inode, lower_new_dentry);
659 if (rc)
660 goto out_lock;
661 ecryptfs_copy_attr_all(new_dir, lower_new_dir_dentry->d_inode);
662 if (new_dir != old_dir)
663 ecryptfs_copy_attr_all(old_dir, lower_old_dir_dentry->d_inode);
664out_lock:
665 unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
666 dput(lower_new_dentry);
667 dput(lower_old_dentry);
668 return rc;
669}
670
671static int
672ecryptfs_readlink(struct dentry *dentry, char __user * buf, int bufsiz)
673{
674 int rc;
675 struct dentry *lower_dentry;
676 char *decoded_name;
677 char *lower_buf;
678 mm_segment_t old_fs;
679 struct ecryptfs_crypt_stat *crypt_stat;
680
681 lower_dentry = ecryptfs_dentry_to_lower(dentry);
682 if (!lower_dentry->d_inode->i_op ||
683 !lower_dentry->d_inode->i_op->readlink) {
684 rc = -EINVAL;
685 goto out;
686 }
687 /* Released in this function */
688 lower_buf = kmalloc(bufsiz, GFP_KERNEL);
689 if (lower_buf == NULL) {
690 ecryptfs_printk(KERN_ERR, "Out of memory\n");
691 rc = -ENOMEM;
692 goto out;
693 }
694 old_fs = get_fs();
695 set_fs(get_ds());
696 ecryptfs_printk(KERN_DEBUG, "Calling readlink w/ "
697 "lower_dentry->d_name.name = [%s]\n",
698 lower_dentry->d_name.name);
699 rc = lower_dentry->d_inode->i_op->readlink(lower_dentry,
700 (char __user *)lower_buf,
701 bufsiz);
702 set_fs(old_fs);
703 if (rc >= 0) {
704 crypt_stat = NULL;
705 rc = ecryptfs_decode_filename(crypt_stat, lower_buf, rc,
706 &decoded_name);
707 if (rc == -ENOMEM)
708 goto out_free_lower_buf;
709 if (rc > 0) {
710 ecryptfs_printk(KERN_DEBUG, "Copying [%d] bytes "
711 "to userspace: [%*s]\n", rc,
712 decoded_name);
713 if (copy_to_user(buf, decoded_name, rc))
714 rc = -EFAULT;
715 }
716 kfree(decoded_name);
717 ecryptfs_copy_attr_atime(dentry->d_inode,
718 lower_dentry->d_inode);
719 }
720out_free_lower_buf:
721 kfree(lower_buf);
722out:
723 return rc;
724}
725
726static void *ecryptfs_follow_link(struct dentry *dentry, struct nameidata *nd)
727{
728 char *buf;
729 int len = PAGE_SIZE, rc;
730 mm_segment_t old_fs;
731
732 /* Released in ecryptfs_put_link(); only release here on error */
733 buf = kmalloc(len, GFP_KERNEL);
734 if (!buf) {
735 rc = -ENOMEM;
736 goto out;
737 }
738 old_fs = get_fs();
739 set_fs(get_ds());
740 ecryptfs_printk(KERN_DEBUG, "Calling readlink w/ "
741 "dentry->d_name.name = [%s]\n", dentry->d_name.name);
742 rc = dentry->d_inode->i_op->readlink(dentry, (char __user *)buf, len);
743 buf[rc] = '\0';
744 set_fs(old_fs);
745 if (rc < 0)
746 goto out_free;
747 rc = 0;
748 nd_set_link(nd, buf);
749 goto out;
750out_free:
751 kfree(buf);
752out:
753 return ERR_PTR(rc);
754}
755
756static void
757ecryptfs_put_link(struct dentry *dentry, struct nameidata *nd, void *ptr)
758{
759 /* Free the char* */
760 kfree(nd_get_link(nd));
761}
762
763/**
764 * upper_size_to_lower_size
765 * @crypt_stat: Crypt_stat associated with file
766 * @upper_size: Size of the upper file
767 *
768 * Calculate the requried size of the lower file based on the
769 * specified size of the upper file. This calculation is based on the
770 * number of headers in the underlying file and the extent size.
771 *
772 * Returns Calculated size of the lower file.
773 */
774static loff_t
775upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
776 loff_t upper_size)
777{
778 loff_t lower_size;
779
780 lower_size = ( crypt_stat->header_extent_size
781 * crypt_stat->num_header_extents_at_front );
782 if (upper_size != 0) {
783 loff_t num_extents;
784
785 num_extents = upper_size >> crypt_stat->extent_shift;
786 if (upper_size & ~crypt_stat->extent_mask)
787 num_extents++;
788 lower_size += (num_extents * crypt_stat->extent_size);
789 }
790 return lower_size;
791}
792
793/**
794 * ecryptfs_truncate
795 * @dentry: The ecryptfs layer dentry
796 * @new_length: The length to expand the file to
797 *
798 * Function to handle truncations modifying the size of the file. Note
799 * that the file sizes are interpolated. When expanding, we are simply
800 * writing strings of 0's out. When truncating, we need to modify the
801 * underlying file size according to the page index interpolations.
802 *
803 * Returns zero on success; non-zero otherwise
804 */
805int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
806{
807 int rc = 0;
808 struct inode *inode = dentry->d_inode;
809 struct dentry *lower_dentry;
810 struct vfsmount *lower_mnt;
811 struct file fake_ecryptfs_file, *lower_file = NULL;
812 struct ecryptfs_crypt_stat *crypt_stat;
813 loff_t i_size = i_size_read(inode);
814 loff_t lower_size_before_truncate;
815 loff_t lower_size_after_truncate;
816
817 if (unlikely((new_length == i_size)))
818 goto out;
819 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
820 /* Set up a fake ecryptfs file, this is used to interface with
821 * the file in the underlying filesystem so that the
822 * truncation has an effect there as well. */
823 memset(&fake_ecryptfs_file, 0, sizeof(fake_ecryptfs_file));
824 fake_ecryptfs_file.f_dentry = dentry;
825 /* Released at out_free: label */
826 ecryptfs_set_file_private(&fake_ecryptfs_file,
827 kmem_cache_alloc(ecryptfs_file_info_cache,
828 SLAB_KERNEL));
829 if (unlikely(!ecryptfs_file_to_private(&fake_ecryptfs_file))) {
830 rc = -ENOMEM;
831 goto out;
832 }
833 lower_dentry = ecryptfs_dentry_to_lower(dentry);
834 /* This dget & mntget is released through fput at out_fput: */
835 dget(lower_dentry);
836 lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry);
837 mntget(lower_mnt);
838 lower_file = dentry_open(lower_dentry, lower_mnt, O_RDWR);
839 if (unlikely(IS_ERR(lower_file))) {
840 rc = PTR_ERR(lower_file);
841 goto out_free;
842 }
843 ecryptfs_set_file_lower(&fake_ecryptfs_file, lower_file);
844 /* Switch on growing or shrinking file */
845 if (new_length > i_size) {
846 rc = ecryptfs_fill_zeros(&fake_ecryptfs_file, new_length);
847 if (rc) {
848 ecryptfs_printk(KERN_ERR,
849 "Problem with fill_zeros\n");
850 goto out_fput;
851 }
852 i_size_write(inode, new_length);
853 rc = ecryptfs_write_inode_size_to_header(lower_file,
854 lower_dentry->d_inode,
855 inode);
856 if (rc) {
857 ecryptfs_printk(KERN_ERR,
858 "Problem with ecryptfs_write"
859 "_inode_size\n");
860 goto out_fput;
861 }
862 } else { /* new_length < i_size_read(inode) */
863 vmtruncate(inode, new_length);
864 ecryptfs_write_inode_size_to_header(lower_file,
865 lower_dentry->d_inode,
866 inode);
867 /* We are reducing the size of the ecryptfs file, and need to
868 * know if we need to reduce the size of the lower file. */
869 lower_size_before_truncate =
870 upper_size_to_lower_size(crypt_stat, i_size);
871 lower_size_after_truncate =
872 upper_size_to_lower_size(crypt_stat, new_length);
873 if (lower_size_after_truncate < lower_size_before_truncate)
874 vmtruncate(lower_dentry->d_inode,
875 lower_size_after_truncate);
876 }
877 /* Update the access times */
878 lower_dentry->d_inode->i_mtime = lower_dentry->d_inode->i_ctime
879 = CURRENT_TIME;
880 mark_inode_dirty_sync(inode);
881out_fput:
882 fput(lower_file);
883out_free:
884 if (ecryptfs_file_to_private(&fake_ecryptfs_file))
885 kmem_cache_free(ecryptfs_file_info_cache,
886 ecryptfs_file_to_private(&fake_ecryptfs_file));
887out:
888 return rc;
889}
890
891static int
892ecryptfs_permission(struct inode *inode, int mask, struct nameidata *nd)
893{
894 int rc;
895
896 if (nd) {
897 struct vfsmount *vfsmnt_save = nd->mnt;
898 struct dentry *dentry_save = nd->dentry;
899
900 nd->mnt = ecryptfs_dentry_to_lower_mnt(nd->dentry);
901 nd->dentry = ecryptfs_dentry_to_lower(nd->dentry);
902 rc = permission(ecryptfs_inode_to_lower(inode), mask, nd);
903 nd->mnt = vfsmnt_save;
904 nd->dentry = dentry_save;
905 } else
906 rc = permission(ecryptfs_inode_to_lower(inode), mask, NULL);
907 return rc;
908}
909
910/**
911 * ecryptfs_setattr
912 * @dentry: dentry handle to the inode to modify
913 * @ia: Structure with flags of what to change and values
914 *
915 * Updates the metadata of an inode. If the update is to the size
916 * i.e. truncation, then ecryptfs_truncate will handle the size modification
917 * of both the ecryptfs inode and the lower inode.
918 *
919 * All other metadata changes will be passed right to the lower filesystem,
920 * and we will just update our inode to look like the lower.
921 */
922static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
923{
924 int rc = 0;
925 struct dentry *lower_dentry;
926 struct inode *inode;
927 struct inode *lower_inode;
928 struct ecryptfs_crypt_stat *crypt_stat;
929
930 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
931 lower_dentry = ecryptfs_dentry_to_lower(dentry);
932 inode = dentry->d_inode;
933 lower_inode = ecryptfs_inode_to_lower(inode);
934 if (ia->ia_valid & ATTR_SIZE) {
935 ecryptfs_printk(KERN_DEBUG,
936 "ia->ia_valid = [0x%x] ATTR_SIZE" " = [0x%x]\n",
937 ia->ia_valid, ATTR_SIZE);
938 rc = ecryptfs_truncate(dentry, ia->ia_size);
939 /* ecryptfs_truncate handles resizing of the lower file */
940 ia->ia_valid &= ~ATTR_SIZE;
941 ecryptfs_printk(KERN_DEBUG, "ia->ia_valid = [%x]\n",
942 ia->ia_valid);
943 if (rc < 0)
944 goto out;
945 }
946 rc = notify_change(lower_dentry, ia);
947out:
948 ecryptfs_copy_attr_all(inode, lower_inode);
949 return rc;
950}
951
952static int
953ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value,
954 size_t size, int flags)
955{
956 int rc = 0;
957 struct dentry *lower_dentry;
958
959 lower_dentry = ecryptfs_dentry_to_lower(dentry);
960 if (!lower_dentry->d_inode->i_op->setxattr) {
961 rc = -ENOSYS;
962 goto out;
963 }
964 mutex_lock(&lower_dentry->d_inode->i_mutex);
965 rc = lower_dentry->d_inode->i_op->setxattr(lower_dentry, name, value,
966 size, flags);
967 mutex_unlock(&lower_dentry->d_inode->i_mutex);
968out:
969 return rc;
970}
971
972static ssize_t
973ecryptfs_getxattr(struct dentry *dentry, const char *name, void *value,
974 size_t size)
975{
976 int rc = 0;
977 struct dentry *lower_dentry;
978
979 lower_dentry = ecryptfs_dentry_to_lower(dentry);
980 if (!lower_dentry->d_inode->i_op->getxattr) {
981 rc = -ENOSYS;
982 goto out;
983 }
984 mutex_lock(&lower_dentry->d_inode->i_mutex);
985 rc = lower_dentry->d_inode->i_op->getxattr(lower_dentry, name, value,
986 size);
987 mutex_unlock(&lower_dentry->d_inode->i_mutex);
988out:
989 return rc;
990}
991
992static ssize_t
993ecryptfs_listxattr(struct dentry *dentry, char *list, size_t size)
994{
995 int rc = 0;
996 struct dentry *lower_dentry;
997
998 lower_dentry = ecryptfs_dentry_to_lower(dentry);
999 if (!lower_dentry->d_inode->i_op->listxattr) {
1000 rc = -ENOSYS;
1001 goto out;
1002 }
1003 mutex_lock(&lower_dentry->d_inode->i_mutex);
1004 rc = lower_dentry->d_inode->i_op->listxattr(lower_dentry, list, size);
1005 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1006out:
1007 return rc;
1008}
1009
1010static int ecryptfs_removexattr(struct dentry *dentry, const char *name)
1011{
1012 int rc = 0;
1013 struct dentry *lower_dentry;
1014
1015 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1016 if (!lower_dentry->d_inode->i_op->removexattr) {
1017 rc = -ENOSYS;
1018 goto out;
1019 }
1020 mutex_lock(&lower_dentry->d_inode->i_mutex);
1021 rc = lower_dentry->d_inode->i_op->removexattr(lower_dentry, name);
1022 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1023out:
1024 return rc;
1025}
1026
1027int ecryptfs_inode_test(struct inode *inode, void *candidate_lower_inode)
1028{
1029 if ((ecryptfs_inode_to_lower(inode)
1030 == (struct inode *)candidate_lower_inode))
1031 return 1;
1032 else
1033 return 0;
1034}
1035
1036int ecryptfs_inode_set(struct inode *inode, void *lower_inode)
1037{
1038 ecryptfs_init_inode(inode, (struct inode *)lower_inode);
1039 return 0;
1040}
1041
1042struct inode_operations ecryptfs_symlink_iops = {
1043 .readlink = ecryptfs_readlink,
1044 .follow_link = ecryptfs_follow_link,
1045 .put_link = ecryptfs_put_link,
1046 .permission = ecryptfs_permission,
1047 .setattr = ecryptfs_setattr,
1048 .setxattr = ecryptfs_setxattr,
1049 .getxattr = ecryptfs_getxattr,
1050 .listxattr = ecryptfs_listxattr,
1051 .removexattr = ecryptfs_removexattr
1052};
1053
1054struct inode_operations ecryptfs_dir_iops = {
1055 .create = ecryptfs_create,
1056 .lookup = ecryptfs_lookup,
1057 .link = ecryptfs_link,
1058 .unlink = ecryptfs_unlink,
1059 .symlink = ecryptfs_symlink,
1060 .mkdir = ecryptfs_mkdir,
1061 .rmdir = ecryptfs_rmdir,
1062 .mknod = ecryptfs_mknod,
1063 .rename = ecryptfs_rename,
1064 .permission = ecryptfs_permission,
1065 .setattr = ecryptfs_setattr,
1066 .setxattr = ecryptfs_setxattr,
1067 .getxattr = ecryptfs_getxattr,
1068 .listxattr = ecryptfs_listxattr,
1069 .removexattr = ecryptfs_removexattr
1070};
1071
1072struct inode_operations ecryptfs_main_iops = {
1073 .permission = ecryptfs_permission,
1074 .setattr = ecryptfs_setattr,
1075 .setxattr = ecryptfs_setxattr,
1076 .getxattr = ecryptfs_getxattr,
1077 .listxattr = ecryptfs_listxattr,
1078 .removexattr = ecryptfs_removexattr
1079};
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-14 00:14:46 -0500