inode.c 32.1 KB
Newer Older
1 2 3 4 5
/**
 * eCryptfs: Linux filesystem encryption layer
 *
 * Copyright (C) 1997-2004 Erez Zadok
 * Copyright (C) 2001-2004 Stony Brook University
6
 * Copyright (C) 2004-2007 International Business Machines Corp.
7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
 *   Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
 *              Michael C. Thompsion <mcthomps@us.ibm.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.
 */

#include <linux/file.h>
#include <linux/vmalloc.h>
#include <linux/pagemap.h>
#include <linux/dcache.h>
#include <linux/namei.h>
#include <linux/mount.h>
32
#include <linux/fs_stack.h>
33
#include <linux/slab.h>
34
#include <linux/xattr.h>
35
#include <asm/unaligned.h>
36 37 38 39 40 41
#include "ecryptfs_kernel.h"

static struct dentry *lock_parent(struct dentry *dentry)
{
	struct dentry *dir;

42
	dir = dget_parent(dentry);
Al Viro's avatar
Al Viro committed
43
	inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
44 45 46 47 48
	return dir;
}

static void unlock_dir(struct dentry *dir)
{
Al Viro's avatar
Al Viro committed
49
	inode_unlock(d_inode(dir));
50 51 52
	dput(dir);
}

53 54
static int ecryptfs_inode_test(struct inode *inode, void *lower_inode)
{
Himangi Saraogi's avatar
Himangi Saraogi committed
55
	return ecryptfs_inode_to_lower(inode) == lower_inode;
56 57
}

58
static int ecryptfs_inode_set(struct inode *inode, void *opaque)
59
{
60 61 62 63 64 65 66
	struct inode *lower_inode = opaque;

	ecryptfs_set_inode_lower(inode, lower_inode);
	fsstack_copy_attr_all(inode, lower_inode);
	/* i_size will be overwritten for encrypted regular files */
	fsstack_copy_inode_size(inode, lower_inode);
	inode->i_ino = lower_inode->i_ino;
67
	inode->i_mapping->a_ops = &ecryptfs_aops;
68 69 70 71 72 73 74 75 76 77 78 79 80 81 82

	if (S_ISLNK(inode->i_mode))
		inode->i_op = &ecryptfs_symlink_iops;
	else if (S_ISDIR(inode->i_mode))
		inode->i_op = &ecryptfs_dir_iops;
	else
		inode->i_op = &ecryptfs_main_iops;

	if (S_ISDIR(inode->i_mode))
		inode->i_fop = &ecryptfs_dir_fops;
	else if (special_file(inode->i_mode))
		init_special_inode(inode, inode->i_mode, inode->i_rdev);
	else
		inode->i_fop = &ecryptfs_main_fops;

83 84 85
	return 0;
}

86 87
static struct inode *__ecryptfs_get_inode(struct inode *lower_inode,
					  struct super_block *sb)
88 89 90
{
	struct inode *inode;

91 92 93 94
	if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb))
		return ERR_PTR(-EXDEV);
	if (!igrab(lower_inode))
		return ERR_PTR(-ESTALE);
95 96 97 98 99
	inode = iget5_locked(sb, (unsigned long)lower_inode,
			     ecryptfs_inode_test, ecryptfs_inode_set,
			     lower_inode);
	if (!inode) {
		iput(lower_inode);
100
		return ERR_PTR(-EACCES);
101
	}
102
	if (!(inode->i_state & I_NEW))
103
		iput(lower_inode);
104 105 106 107 108 109 110 111 112 113 114 115

	return inode;
}

struct inode *ecryptfs_get_inode(struct inode *lower_inode,
				 struct super_block *sb)
{
	struct inode *inode = __ecryptfs_get_inode(lower_inode, sb);

	if (!IS_ERR(inode) && (inode->i_state & I_NEW))
		unlock_new_inode(inode);

116 117 118 119 120 121 122 123 124 125 126 127 128 129
	return inode;
}

/**
 * ecryptfs_interpose
 * @lower_dentry: Existing dentry in the lower filesystem
 * @dentry: ecryptfs' dentry
 * @sb: ecryptfs's super_block
 *
 * Interposes upper and lower dentries.
 *
 * Returns zero on success; non-zero otherwise
 */
static int ecryptfs_interpose(struct dentry *lower_dentry,
130
			      struct dentry *dentry, struct super_block *sb)
131
{
132
	struct inode *inode = ecryptfs_get_inode(d_inode(lower_dentry), sb);
133

134 135
	if (IS_ERR(inode))
		return PTR_ERR(inode);
136 137
	d_instantiate(dentry, inode);

138 139 140
	return 0;
}

141 142 143 144 145 146 147 148 149 150
static int ecryptfs_do_unlink(struct inode *dir, struct dentry *dentry,
			      struct inode *inode)
{
	struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
	struct inode *lower_dir_inode = ecryptfs_inode_to_lower(dir);
	struct dentry *lower_dir_dentry;
	int rc;

	dget(lower_dentry);
	lower_dir_dentry = lock_parent(lower_dentry);
151
	rc = vfs_unlink(lower_dir_inode, lower_dentry, NULL);
152 153 154 155 156 157 158 159 160 161 162 163 164 165
	if (rc) {
		printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc);
		goto out_unlock;
	}
	fsstack_copy_attr_times(dir, lower_dir_inode);
	set_nlink(inode, ecryptfs_inode_to_lower(inode)->i_nlink);
	inode->i_ctime = dir->i_ctime;
	d_drop(dentry);
out_unlock:
	unlock_dir(lower_dir_dentry);
	dput(lower_dentry);
	return rc;
}

166 167 168 169 170 171 172 173 174 175
/**
 * ecryptfs_do_create
 * @directory_inode: inode of the new file's dentry's parent in ecryptfs
 * @ecryptfs_dentry: New file's dentry in ecryptfs
 * @mode: The mode of the new file
 *
 * Creates the underlying file and the eCryptfs inode which will link to
 * it. It will also update the eCryptfs directory inode to mimic the
 * stat of the lower directory inode.
 *
176
 * Returns the new eCryptfs inode on success; an ERR_PTR on error condition
177
 */
178
static struct inode *
179
ecryptfs_do_create(struct inode *directory_inode,
180
		   struct dentry *ecryptfs_dentry, umode_t mode)
181 182 183 184
{
	int rc;
	struct dentry *lower_dentry;
	struct dentry *lower_dir_dentry;
185
	struct inode *inode;
186 187 188

	lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
	lower_dir_dentry = lock_parent(lower_dentry);
189
	rc = vfs_create(d_inode(lower_dir_dentry), lower_dentry, mode, true);
190
	if (rc) {
191
		printk(KERN_ERR "%s: Failure to create dentry in lower fs; "
192
		       "rc = [%d]\n", __func__, rc);
193
		inode = ERR_PTR(rc);
194
		goto out_lock;
195
	}
196
	inode = __ecryptfs_get_inode(d_inode(lower_dentry),
197
				     directory_inode->i_sb);
198
	if (IS_ERR(inode)) {
199
		vfs_unlink(d_inode(lower_dir_dentry), lower_dentry, NULL);
200
		goto out_lock;
201
	}
202 203
	fsstack_copy_attr_times(directory_inode, d_inode(lower_dir_dentry));
	fsstack_copy_inode_size(directory_inode, d_inode(lower_dir_dentry));
204 205
out_lock:
	unlock_dir(lower_dir_dentry);
206
	return inode;
207 208 209 210 211 212 213 214 215 216
}

/**
 * ecryptfs_initialize_file
 *
 * Cause the file to be changed from a basic empty file to an ecryptfs
 * file with a header and first data page.
 *
 * Returns zero on success
 */
217 218
int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry,
			     struct inode *ecryptfs_inode)
219
{
220
	struct ecryptfs_crypt_stat *crypt_stat =
221
		&ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat;
222 223
	int rc = 0;

224
	if (S_ISDIR(ecryptfs_inode->i_mode)) {
225
		ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
226
		crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
227
		goto out;
228 229
	}
	ecryptfs_printk(KERN_DEBUG, "Initializing crypto context\n");
230
	rc = ecryptfs_new_file_context(ecryptfs_inode);
231
	if (rc) {
232 233 234
		ecryptfs_printk(KERN_ERR, "Error creating new file "
				"context; rc = [%d]\n", rc);
		goto out;
235
	}
236
	rc = ecryptfs_get_lower_file(ecryptfs_dentry, ecryptfs_inode);
237 238
	if (rc) {
		printk(KERN_ERR "%s: Error attempting to initialize "
239
			"the lower file for the dentry with name "
David Howells's avatar
David Howells committed
240 241
			"[%pd]; rc = [%d]\n", __func__,
			ecryptfs_dentry, rc);
242
		goto out;
243
	}
244
	rc = ecryptfs_write_metadata(ecryptfs_dentry, ecryptfs_inode);
245
	if (rc)
246
		printk(KERN_ERR "Error writing headers; rc = [%d]\n", rc);
247
	ecryptfs_put_lower_file(ecryptfs_inode);
248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263
out:
	return rc;
}

/**
 * ecryptfs_create
 * @dir: The inode of the directory in which to create the file.
 * @dentry: The eCryptfs dentry
 * @mode: The mode of the new file.
 *
 * Creates a new file.
 *
 * Returns zero on success; non-zero on error condition
 */
static int
ecryptfs_create(struct inode *directory_inode, struct dentry *ecryptfs_dentry,
264
		umode_t mode, bool excl)
265
{
266
	struct inode *ecryptfs_inode;
267 268
	int rc;

269 270
	ecryptfs_inode = ecryptfs_do_create(directory_inode, ecryptfs_dentry,
					    mode);
271
	if (IS_ERR(ecryptfs_inode)) {
272 273
		ecryptfs_printk(KERN_WARNING, "Failed to create file in"
				"lower filesystem\n");
274
		rc = PTR_ERR(ecryptfs_inode);
275 276 277 278
		goto out;
	}
	/* At this point, a file exists on "disk"; we need to make sure
	 * that this on disk file is prepared to be an ecryptfs file */
279 280
	rc = ecryptfs_initialize_file(ecryptfs_dentry, ecryptfs_inode);
	if (rc) {
281 282
		ecryptfs_do_unlink(directory_inode, ecryptfs_dentry,
				   ecryptfs_inode);
Al Viro's avatar
Al Viro committed
283
		iget_failed(ecryptfs_inode);
284 285 286
		goto out;
	}
	unlock_new_inode(ecryptfs_inode);
287
	d_instantiate(ecryptfs_dentry, ecryptfs_inode);
288 289 290 291
out:
	return rc;
}

292 293 294 295 296 297 298 299 300
static int ecryptfs_i_size_read(struct dentry *dentry, struct inode *inode)
{
	struct ecryptfs_crypt_stat *crypt_stat;
	int rc;

	rc = ecryptfs_get_lower_file(dentry, inode);
	if (rc) {
		printk(KERN_ERR "%s: Error attempting to initialize "
			"the lower file for the dentry with name "
David Howells's avatar
David Howells committed
301 302
			"[%pd]; rc = [%d]\n", __func__,
			dentry, rc);
303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322
		return rc;
	}

	crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
	/* TODO: lock for crypt_stat comparison */
	if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED))
		ecryptfs_set_default_sizes(crypt_stat);

	rc = ecryptfs_read_and_validate_header_region(inode);
	ecryptfs_put_lower_file(inode);
	if (rc) {
		rc = ecryptfs_read_and_validate_xattr_region(dentry, inode);
		if (!rc)
			crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
	}

	/* Must return 0 to allow non-eCryptfs files to be looked up, too */
	return 0;
}

323
/**
324
 * ecryptfs_lookup_interpose - Dentry interposition for a lookup
325
 */
326 327
static struct dentry *ecryptfs_lookup_interpose(struct dentry *dentry,
				     struct dentry *lower_dentry)
328
{
329
	struct inode *inode, *lower_inode = d_inode(lower_dentry);
330
	struct ecryptfs_dentry_info *dentry_info;
331
	struct vfsmount *lower_mnt;
332 333 334 335 336
	int rc = 0;

	dentry_info = kmem_cache_alloc(ecryptfs_dentry_info_cache, GFP_KERNEL);
	if (!dentry_info) {
		dput(lower_dentry);
337
		return ERR_PTR(-ENOMEM);
338
	}
339 340

	lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(dentry->d_parent));
341 342
	fsstack_copy_attr_atime(d_inode(dentry->d_parent),
				d_inode(lower_dentry->d_parent));
Al Viro's avatar
Al Viro committed
343
	BUG_ON(!d_count(lower_dentry));
344 345

	ecryptfs_set_dentry_private(dentry, dentry_info);
346 347
	dentry_info->lower_path.mnt = lower_mnt;
	dentry_info->lower_path.dentry = lower_dentry;
348

349
	if (d_really_is_negative(lower_dentry)) {
350
		/* We want to add because we couldn't find in lower */
351
		d_add(dentry, NULL);
352
		return NULL;
353
	}
354
	inode = __ecryptfs_get_inode(lower_inode, dentry->d_sb);
355
	if (IS_ERR(inode)) {
356 357
		printk(KERN_ERR "%s: Error interposing; rc = [%ld]\n",
		       __func__, PTR_ERR(inode));
358
		return ERR_CAST(inode);
359
	}
360 361
	if (S_ISREG(inode->i_mode)) {
		rc = ecryptfs_i_size_read(dentry, inode);
362
		if (rc) {
363
			make_bad_inode(inode);
364
			return ERR_PTR(rc);
365 366
		}
	}
367

368 369
	if (inode->i_state & I_NEW)
		unlock_new_inode(inode);
370
	return d_splice_alias(inode, dentry);
371 372 373 374 375 376
}

/**
 * ecryptfs_lookup
 * @ecryptfs_dir_inode: The eCryptfs directory inode
 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
377
 * @flags: lookup flags
378 379 380 381 382 383
 *
 * Find a file on disk. If the file does not exist, then we'll add it to the
 * dentry cache and continue on to read it from the disk.
 */
static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
				      struct dentry *ecryptfs_dentry,
384
				      unsigned int flags)
385 386
{
	char *encrypted_and_encoded_name = NULL;
387
	struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
388
	struct dentry *lower_dir_dentry, *lower_dentry;
389 390
	const char *name = ecryptfs_dentry->d_name.name;
	size_t len = ecryptfs_dentry->d_name.len;
391
	struct dentry *res;
392 393 394
	int rc = 0;

	lower_dir_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry->d_parent);
395

396 397
	mount_crypt_stat = &ecryptfs_superblock_to_private(
				ecryptfs_dentry->d_sb)->mount_crypt_stat;
398 399 400 401 402 403 404 405 406 407 408
	if (mount_crypt_stat
	    && (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)) {
		rc = ecryptfs_encrypt_and_encode_filename(
			&encrypted_and_encoded_name, &len,
			mount_crypt_stat, name, len);
		if (rc) {
			printk(KERN_ERR "%s: Error attempting to encrypt and encode "
			       "filename; rc = [%d]\n", __func__, rc);
			return ERR_PTR(rc);
		}
		name = encrypted_and_encoded_name;
409
	}
410 411

	lower_dentry = lookup_one_len_unlocked(name, lower_dir_dentry, len);
412
	if (IS_ERR(lower_dentry)) {
413
		ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
414 415
				"[%ld] on lower_dentry = [%s]\n", __func__,
				PTR_ERR(lower_dentry),
416
				name);
417
		res = ERR_CAST(lower_dentry);
418 419
	} else {
		res = ecryptfs_lookup_interpose(ecryptfs_dentry, lower_dentry);
420 421
	}
	kfree(encrypted_and_encoded_name);
422
	return res;
423 424 425 426 427 428 429 430 431 432 433
}

static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
			 struct dentry *new_dentry)
{
	struct dentry *lower_old_dentry;
	struct dentry *lower_new_dentry;
	struct dentry *lower_dir_dentry;
	u64 file_size_save;
	int rc;

434
	file_size_save = i_size_read(d_inode(old_dentry));
435 436 437 438 439
	lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
	lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
	dget(lower_old_dentry);
	dget(lower_new_dentry);
	lower_dir_dentry = lock_parent(lower_new_dentry);
440
	rc = vfs_link(lower_old_dentry, d_inode(lower_dir_dentry),
441
		      lower_new_dentry, NULL);
442
	if (rc || d_really_is_negative(lower_new_dentry))
443
		goto out_lock;
444
	rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb);
445 446
	if (rc)
		goto out_lock;
447 448 449 450 451
	fsstack_copy_attr_times(dir, d_inode(lower_dir_dentry));
	fsstack_copy_inode_size(dir, d_inode(lower_dir_dentry));
	set_nlink(d_inode(old_dentry),
		  ecryptfs_inode_to_lower(d_inode(old_dentry))->i_nlink);
	i_size_write(d_inode(new_dentry), file_size_save);
452 453 454 455 456 457 458 459 460
out_lock:
	unlock_dir(lower_dir_dentry);
	dput(lower_new_dentry);
	dput(lower_old_dentry);
	return rc;
}

static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
{
461
	return ecryptfs_do_unlink(dir, dentry, d_inode(dentry));
462 463 464 465 466 467 468 469 470
}

static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry,
			    const char *symname)
{
	int rc;
	struct dentry *lower_dentry;
	struct dentry *lower_dir_dentry;
	char *encoded_symname;
471 472
	size_t encoded_symlen;
	struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
473 474 475 476

	lower_dentry = ecryptfs_dentry_to_lower(dentry);
	dget(lower_dentry);
	lower_dir_dentry = lock_parent(lower_dentry);
477 478 479 480 481 482 483
	mount_crypt_stat = &ecryptfs_superblock_to_private(
		dir->i_sb)->mount_crypt_stat;
	rc = ecryptfs_encrypt_and_encode_filename(&encoded_symname,
						  &encoded_symlen,
						  mount_crypt_stat, symname,
						  strlen(symname));
	if (rc)
484
		goto out_lock;
485
	rc = vfs_symlink(d_inode(lower_dir_dentry), lower_dentry,
486
			 encoded_symname);
487
	kfree(encoded_symname);
488
	if (rc || d_really_is_negative(lower_dentry))
489
		goto out_lock;
490
	rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
491 492
	if (rc)
		goto out_lock;
493 494
	fsstack_copy_attr_times(dir, d_inode(lower_dir_dentry));
	fsstack_copy_inode_size(dir, d_inode(lower_dir_dentry));
495 496 497
out_lock:
	unlock_dir(lower_dir_dentry);
	dput(lower_dentry);
498
	if (d_really_is_negative(dentry))
499 500 501 502
		d_drop(dentry);
	return rc;
}

503
static int ecryptfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
504 505 506 507 508 509 510
{
	int rc;
	struct dentry *lower_dentry;
	struct dentry *lower_dir_dentry;

	lower_dentry = ecryptfs_dentry_to_lower(dentry);
	lower_dir_dentry = lock_parent(lower_dentry);
511 512
	rc = vfs_mkdir(d_inode(lower_dir_dentry), lower_dentry, mode);
	if (rc || d_really_is_negative(lower_dentry))
513
		goto out;
514
	rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
515 516
	if (rc)
		goto out;
517 518 519
	fsstack_copy_attr_times(dir, d_inode(lower_dir_dentry));
	fsstack_copy_inode_size(dir, d_inode(lower_dir_dentry));
	set_nlink(dir, d_inode(lower_dir_dentry)->i_nlink);
520 521
out:
	unlock_dir(lower_dir_dentry);
522
	if (d_really_is_negative(dentry))
523 524 525 526 527 528 529 530
		d_drop(dentry);
	return rc;
}

static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
{
	struct dentry *lower_dentry;
	struct dentry *lower_dir_dentry;
531
	int rc;
532 533

	lower_dentry = ecryptfs_dentry_to_lower(dentry);
534
	dget(dentry);
535
	lower_dir_dentry = lock_parent(lower_dentry);
536
	dget(lower_dentry);
537
	rc = vfs_rmdir(d_inode(lower_dir_dentry), lower_dentry);
538
	dput(lower_dentry);
539 540 541 542
	if (!rc && d_really_is_positive(dentry))
		clear_nlink(d_inode(dentry));
	fsstack_copy_attr_times(dir, d_inode(lower_dir_dentry));
	set_nlink(dir, d_inode(lower_dir_dentry)->i_nlink);
543 544 545
	unlock_dir(lower_dir_dentry);
	if (!rc)
		d_drop(dentry);
546
	dput(dentry);
547 548 549 550
	return rc;
}

static int
Al Viro's avatar
Al Viro committed
551
ecryptfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
552 553 554 555 556 557 558
{
	int rc;
	struct dentry *lower_dentry;
	struct dentry *lower_dir_dentry;

	lower_dentry = ecryptfs_dentry_to_lower(dentry);
	lower_dir_dentry = lock_parent(lower_dentry);
559 560
	rc = vfs_mknod(d_inode(lower_dir_dentry), lower_dentry, mode, dev);
	if (rc || d_really_is_negative(lower_dentry))
561
		goto out;
562
	rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
563 564
	if (rc)
		goto out;
565 566
	fsstack_copy_attr_times(dir, d_inode(lower_dir_dentry));
	fsstack_copy_inode_size(dir, d_inode(lower_dir_dentry));
567 568
out:
	unlock_dir(lower_dir_dentry);
569
	if (d_really_is_negative(dentry))
570 571 572 573 574 575
		d_drop(dentry);
	return rc;
}

static int
ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
576 577
		struct inode *new_dir, struct dentry *new_dentry,
		unsigned int flags)
578 579 580 581 582 583
{
	int rc;
	struct dentry *lower_old_dentry;
	struct dentry *lower_new_dentry;
	struct dentry *lower_old_dir_dentry;
	struct dentry *lower_new_dir_dentry;
584
	struct dentry *trap = NULL;
585
	struct inode *target_inode;
586

587 588 589
	if (flags)
		return -EINVAL;

590 591 592 593 594 595
	lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
	lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
	dget(lower_old_dentry);
	dget(lower_new_dentry);
	lower_old_dir_dentry = dget_parent(lower_old_dentry);
	lower_new_dir_dentry = dget_parent(lower_new_dentry);
596
	target_inode = d_inode(new_dentry);
597 598 599 600 601 602 603 604 605 606 607
	trap = lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
	/* source should not be ancestor of target */
	if (trap == lower_old_dentry) {
		rc = -EINVAL;
		goto out_lock;
	}
	/* target should not be ancestor of source */
	if (trap == lower_new_dentry) {
		rc = -ENOTEMPTY;
		goto out_lock;
	}
608 609
	rc = vfs_rename(d_inode(lower_old_dir_dentry), lower_old_dentry,
			d_inode(lower_new_dir_dentry), lower_new_dentry,
610
			NULL, 0);
611 612
	if (rc)
		goto out_lock;
613 614 615
	if (target_inode)
		fsstack_copy_attr_all(target_inode,
				      ecryptfs_inode_to_lower(target_inode));
616
	fsstack_copy_attr_all(new_dir, d_inode(lower_new_dir_dentry));
617
	if (new_dir != old_dir)
618
		fsstack_copy_attr_all(old_dir, d_inode(lower_old_dir_dentry));
619 620
out_lock:
	unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
621 622
	dput(lower_new_dir_dentry);
	dput(lower_old_dir_dentry);
623 624 625 626 627
	dput(lower_new_dentry);
	dput(lower_old_dentry);
	return rc;
}

628
static char *ecryptfs_readlink_lower(struct dentry *dentry, size_t *bufsiz)
629
{
630
	DEFINE_DELAYED_CALL(done);
631
	struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
632
	const char *link;
633
	char *buf;
634
	int rc;
635

636 637 638 639
	link = vfs_get_link(lower_dentry, &done);
	if (IS_ERR(link))
		return ERR_CAST(link);

640
	rc = ecryptfs_decode_and_decrypt_filename(&buf, bufsiz, dentry->d_sb,
641 642 643 644 645 646
						  link, strlen(link));
	do_delayed_call(&done);
	if (rc)
		return ERR_PTR(rc);

	return buf;
647 648
}

649
static const char *ecryptfs_get_link(struct dentry *dentry,
650 651
				     struct inode *inode,
				     struct delayed_call *done)
652
{
653
	size_t len;
654 655 656 657 658 659
	char *buf;

	if (!dentry)
		return ERR_PTR(-ECHILD);

	buf = ecryptfs_readlink_lower(dentry, &len);
660
	if (IS_ERR(buf))
661
		return buf;
662 663
	fsstack_copy_attr_atime(d_inode(dentry),
				d_inode(ecryptfs_dentry_to_lower(dentry)));
664
	buf[len] = '\0';
665 666
	set_delayed_call(done, kfree_link, buf);
	return buf;
667 668 669 670 671 672 673
}

/**
 * upper_size_to_lower_size
 * @crypt_stat: Crypt_stat associated with file
 * @upper_size: Size of the upper file
 *
674
 * Calculate the required size of the lower file based on the
675 676 677 678 679 680 681 682 683 684 685
 * specified size of the upper file. This calculation is based on the
 * number of headers in the underlying file and the extent size.
 *
 * Returns Calculated size of the lower file.
 */
static loff_t
upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
			 loff_t upper_size)
{
	loff_t lower_size;

686
	lower_size = ecryptfs_lower_header_size(crypt_stat);
687 688 689 690 691 692 693 694 695 696 697 698
	if (upper_size != 0) {
		loff_t num_extents;

		num_extents = upper_size >> crypt_stat->extent_shift;
		if (upper_size & ~crypt_stat->extent_mask)
			num_extents++;
		lower_size += (num_extents * crypt_stat->extent_size);
	}
	return lower_size;
}

/**
699
 * truncate_upper
700
 * @dentry: The ecryptfs layer dentry
701 702
 * @ia: Address of the ecryptfs inode's attributes
 * @lower_ia: Address of the lower inode's attributes
703 704 705
 *
 * Function to handle truncations modifying the size of the file. Note
 * that the file sizes are interpolated. When expanding, we are simply
706 707 708 709 710
 * writing strings of 0's out. When truncating, we truncate the upper
 * inode and update the lower_ia according to the page index
 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
 * the caller must use lower_ia in a call to notify_change() to perform
 * the truncation of the lower inode.
711 712 713
 *
 * Returns zero on success; non-zero otherwise
 */
714 715
static int truncate_upper(struct dentry *dentry, struct iattr *ia,
			  struct iattr *lower_ia)
716 717
{
	int rc = 0;
718
	struct inode *inode = d_inode(dentry);
719 720 721 722 723
	struct ecryptfs_crypt_stat *crypt_stat;
	loff_t i_size = i_size_read(inode);
	loff_t lower_size_before_truncate;
	loff_t lower_size_after_truncate;

724 725
	if (unlikely((ia->ia_size == i_size))) {
		lower_ia->ia_valid &= ~ATTR_SIZE;
726
		return 0;
727
	}
728
	rc = ecryptfs_get_lower_file(dentry, inode);
729 730
	if (rc)
		return rc;
731
	crypt_stat = &ecryptfs_inode_to_private(d_inode(dentry))->crypt_stat;
732
	/* Switch on growing or shrinking file */
733
	if (ia->ia_size > i_size) {
734 735
		char zero[] = { 0x00 };

736
		lower_ia->ia_valid &= ~ATTR_SIZE;
737 738 739 740
		/* Write a single 0 at the last position of the file;
		 * this triggers code that will fill in 0's throughout
		 * the intermediate portion of the previous end of the
		 * file and the new and of the file */
741
		rc = ecryptfs_write(inode, zero,
742 743 744 745
				    (ia->ia_size - 1), 1);
	} else { /* ia->ia_size < i_size_read(inode) */
		/* We're chopping off all the pages down to the page
		 * in which ia->ia_size is located. Fill in the end of
746 747
		 * that page from (ia->ia_size & ~PAGE_MASK) to
		 * PAGE_SIZE with zeros. */
748 749
		size_t num_zeros = (PAGE_SIZE
				    - (ia->ia_size & ~PAGE_MASK));
750

751
		if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
752
			truncate_setsize(inode, ia->ia_size);
753 754
			lower_ia->ia_size = ia->ia_size;
			lower_ia->ia_valid |= ATTR_SIZE;
755
			goto out;
756
		}
757 758 759 760 761 762
		if (num_zeros) {
			char *zeros_virt;

			zeros_virt = kzalloc(num_zeros, GFP_KERNEL);
			if (!zeros_virt) {
				rc = -ENOMEM;
763
				goto out;
764
			}
765
			rc = ecryptfs_write(inode, zeros_virt,
766
					    ia->ia_size, num_zeros);
767
			kfree(zeros_virt);
768
			if (rc) {
769 770 771
				printk(KERN_ERR "Error attempting to zero out "
				       "the remainder of the end page on "
				       "reducing truncate; rc = [%d]\n", rc);
772
				goto out;
773 774
			}
		}
775
		truncate_setsize(inode, ia->ia_size);
776
		rc = ecryptfs_write_inode_size_to_metadata(inode);
777 778 779 780
		if (rc) {
			printk(KERN_ERR	"Problem with "
			       "ecryptfs_write_inode_size_to_metadata; "
			       "rc = [%d]\n", rc);
781
			goto out;
782
		}
783 784 785 786 787
		/* We are reducing the size of the ecryptfs file, and need to
		 * know if we need to reduce the size of the lower file. */
		lower_size_before_truncate =
		    upper_size_to_lower_size(crypt_stat, i_size);
		lower_size_after_truncate =
788 789 790 791 792 793
		    upper_size_to_lower_size(crypt_stat, ia->ia_size);
		if (lower_size_after_truncate < lower_size_before_truncate) {
			lower_ia->ia_size = lower_size_after_truncate;
			lower_ia->ia_valid |= ATTR_SIZE;
		} else
			lower_ia->ia_valid &= ~ATTR_SIZE;
794 795
	}
out:
796
	ecryptfs_put_lower_file(inode);
797 798 799
	return rc;
}

800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821
static int ecryptfs_inode_newsize_ok(struct inode *inode, loff_t offset)
{
	struct ecryptfs_crypt_stat *crypt_stat;
	loff_t lower_oldsize, lower_newsize;

	crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
	lower_oldsize = upper_size_to_lower_size(crypt_stat,
						 i_size_read(inode));
	lower_newsize = upper_size_to_lower_size(crypt_stat, offset);
	if (lower_newsize > lower_oldsize) {
		/*
		 * The eCryptfs inode and the new *lower* size are mixed here
		 * because we may not have the lower i_mutex held and/or it may
		 * not be appropriate to call inode_newsize_ok() with inodes
		 * from other filesystems.
		 */
		return inode_newsize_ok(inode, lower_newsize);
	}

	return 0;
}

822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837
/**
 * ecryptfs_truncate
 * @dentry: The ecryptfs layer dentry
 * @new_length: The length to expand the file to
 *
 * Simple function that handles the truncation of an eCryptfs inode and
 * its corresponding lower inode.
 *
 * Returns zero on success; non-zero otherwise
 */
int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
{
	struct iattr ia = { .ia_valid = ATTR_SIZE, .ia_size = new_length };
	struct iattr lower_ia = { .ia_valid = 0 };
	int rc;

838
	rc = ecryptfs_inode_newsize_ok(d_inode(dentry), new_length);
839 840 841
	if (rc)
		return rc;

842 843 844 845
	rc = truncate_upper(dentry, &ia, &lower_ia);
	if (!rc && lower_ia.ia_valid & ATTR_SIZE) {
		struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);

Al Viro's avatar
Al Viro committed
846
		inode_lock(d_inode(lower_dentry));
847
		rc = notify_change(lower_dentry, &lower_ia, NULL);
Al Viro's avatar
Al Viro committed
848
		inode_unlock(d_inode(lower_dentry));
849 850 851 852
	}
	return rc;
}

853
static int
854
ecryptfs_permission(struct inode *inode, int mask)
855
{
856
	return inode_permission(ecryptfs_inode_to_lower(inode), mask);
857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874
}

/**
 * ecryptfs_setattr
 * @dentry: dentry handle to the inode to modify
 * @ia: Structure with flags of what to change and values
 *
 * Updates the metadata of an inode. If the update is to the size
 * i.e. truncation, then ecryptfs_truncate will handle the size modification
 * of both the ecryptfs inode and the lower inode.
 *
 * All other metadata changes will be passed right to the lower filesystem,
 * and we will just update our inode to look like the lower.
 */
static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
{
	int rc = 0;
	struct dentry *lower_dentry;
875
	struct iattr lower_ia;
876 877 878 879
	struct inode *inode;
	struct inode *lower_inode;
	struct ecryptfs_crypt_stat *crypt_stat;

880
	crypt_stat = &ecryptfs_inode_to_private(d_inode(dentry))->crypt_stat;
881 882 883 884 885
	if (!(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED)) {
		rc = ecryptfs_init_crypt_stat(crypt_stat);
		if (rc)
			return rc;
	}
886
	inode = d_inode(dentry);
887
	lower_inode = ecryptfs_inode_to_lower(inode);
888 889
	lower_dentry = ecryptfs_dentry_to_lower(dentry);
	mutex_lock(&crypt_stat->cs_mutex);
890
	if (d_is_dir(dentry))
891
		crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
892
	else if (d_is_reg(dentry)
893 894
		 && (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
		     || !(crypt_stat->flags & ECRYPTFS_KEY_VALID))) {
895 896 897 898
		struct ecryptfs_mount_crypt_stat *mount_crypt_stat;

		mount_crypt_stat = &ecryptfs_superblock_to_private(
			dentry->d_sb)->mount_crypt_stat;
899
		rc = ecryptfs_get_lower_file(dentry, inode);
900 901 902 903
		if (rc) {
			mutex_unlock(&crypt_stat->cs_mutex);
			goto out;
		}
904
		rc = ecryptfs_read_metadata(dentry);
905
		ecryptfs_put_lower_file(inode);
906
		if (rc) {
907 908 909
			if (!(mount_crypt_stat->flags
			      & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
				rc = -EIO;
910
				printk(KERN_WARNING "Either the lower file "
911
				       "is not in a valid eCryptfs format, "
912 913
				       "or the key could not be retrieved. "
				       "Plaintext passthrough mode is not "
914 915 916 917 918
				       "enabled; returning -EIO\n");
				mutex_unlock(&crypt_stat->cs_mutex);
				goto out;
			}
			rc = 0;
919 920
			crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED
					       | ECRYPTFS_ENCRYPTED);
921 922 923
		}
	}
	mutex_unlock(&crypt_stat->cs_mutex);
924

925
	rc = setattr_prepare(dentry, ia);
926 927 928 929 930 931 932 933
	if (rc)
		goto out;
	if (ia->ia_valid & ATTR_SIZE) {
		rc = ecryptfs_inode_newsize_ok(inode, ia->ia_size);
		if (rc)
			goto out;
	}

934 935 936
	memcpy(&lower_ia, ia, sizeof(lower_ia));
	if (ia->ia_valid & ATTR_FILE)
		lower_ia.ia_file = ecryptfs_file_to_lower(ia->ia_file);
937
	if (ia->ia_valid & ATTR_SIZE) {
938
		rc = truncate_upper(dentry, ia, &lower_ia);
939 940 941
		if (rc < 0)
			goto out;
	}
942 943 944 945 946

	/*
	 * mode change is for clearing setuid/setgid bits. Allow lower fs
	 * to interpret this in its own way.
	 */
947 948
	if (lower_ia.ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
		lower_ia.ia_valid &= ~ATTR_MODE;
949

Al Viro's avatar
Al Viro committed
950
	inode_lock(d_inode(lower_dentry));
951
	rc = notify_change(lower_dentry, &lower_ia, NULL);
Al Viro's avatar
Al Viro committed
952
	inode_unlock(d_inode(lower_dentry));
953
out:
954
	fsstack_copy_attr_all(inode, lower_inode);
955 956 957
	return rc;
}

958 959
static int ecryptfs_getattr_link(const struct path *path, struct kstat *stat,
				 u32 request_mask, unsigned int flags)
960
{
961
	struct dentry *dentry = path->dentry;
962 963 964 965 966
	struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
	int rc = 0;

	mount_crypt_stat = &ecryptfs_superblock_to_private(
						dentry->d_sb)->mount_crypt_stat;
967
	generic_fillattr(d_inode(dentry), stat);
968 969 970 971
	if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) {
		char *target;
		size_t targetsiz;

972 973
		target = ecryptfs_readlink_lower(dentry, &targetsiz);
		if (!IS_ERR(target)) {
974 975
			kfree(target);
			stat->size = targetsiz;
976 977
		} else {
			rc = PTR_ERR(target);
978 979 980 981 982
		}
	}
	return rc;
}

983 984
static int ecryptfs_getattr(const struct path *path, struct kstat *stat,
			    u32 request_mask, unsigned int flags)
985
{
986
	struct dentry *dentry = path->dentry;
987 988 989
	struct kstat lower_stat;
	int rc;

990 991
	rc = vfs_getattr(ecryptfs_dentry_to_lower_path(dentry), &lower_stat,
			 request_mask, flags);
992
	if (!rc) {
993 994 995
		fsstack_copy_attr_all(d_inode(dentry),
				      ecryptfs_inode_to_lower(d_inode(dentry)));
		generic_fillattr(d_inode(dentry), stat);
996 997 998 999 1000
		stat->blocks = lower_stat.blocks;
	}
	return rc;
}

1001
int
1002 1003
ecryptfs_setxattr(struct dentry *dentry, struct inode *inode,
		  const char *name, const void *value,
1004 1005
		  size_t size, int flags)
{
1006
	int rc;
1007 1008 1009
	struct dentry *lower_dentry;

	lower_dentry = ecryptfs_dentry_to_lower(dentry);
1010
	if (!(d_inode(lower_dentry)->i_opflags & IOP_XATTR)) {
1011
		rc = -EOPNOTSUPP;
1012 1013
		goto out;
	}
1014
	rc = vfs_setxattr(lower_dentry, name, value, size, flags);
1015 1016
	if (!rc && inode)
		fsstack_copy_attr_all(inode, d_inode(lower_dentry));
1017 1018 1019 1020
out:
	return rc;
}

1021
ssize_t
1022 1023
ecryptfs_getxattr_lower(struct dentry *lower_dentry, struct inode *lower_inode,
			const char *name, void *value, size_t size)
1024
{
1025
	int rc;
1026

1027
	if (!(lower_inode->i_opflags & IOP_XATTR)) {
1028
		rc = -EOPNOTSUPP;
1029 1030
		goto out;
	}
1031
	inode_lock(lower_inode);
1032
	rc = __vfs_getxattr(lower_dentry, lower_inode, name, value, size);
1033
	inode_unlock(lower_inode);
1034 1035 1036 1037
out:
	return rc;
}

1038
static ssize_t
1039 1040
ecryptfs_getxattr(struct dentry *dentry, struct inode *inode,
		  const char *name, void *value, size_t size)
1041
{
1042 1043 1044
	return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry),
				       ecryptfs_inode_to_lower(inode),
				       name, value, size);
1045 1046 1047 1048 1049 1050 1051 1052 1053
}

static ssize_t
ecryptfs_listxattr(struct dentry *dentry, char *list, size_t size)
{
	int rc = 0;
	struct dentry *lower_dentry;

	lower_dentry = ecryptfs_dentry_to_lower(dentry);
1054
	if (!d_inode(lower_dentry)->i_op->listxattr) {
1055
		rc = -EOPNOTSUPP;
1056 1057
		goto out;
	}
Al Viro's avatar
Al Viro committed
1058
	inode_lock(d_inode(lower_dentry));
1059
	rc = d_inode(lower_dentry)->i_op->listxattr(lower_dentry, list, size);
Al Viro's avatar
Al Viro committed
1060
	inode_unlock(d_inode(lower_dentry));
1061 1062 1063 1064
out:
	return rc;
}

1065 1066
static int ecryptfs_removexattr(struct dentry *dentry, struct inode *inode,
				const char *name)
1067
{
1068
	int rc;
1069
	struct dentry *lower_dentry;
1070
	struct inode *lower_inode;
1071 1072

	lower_dentry = ecryptfs_dentry_to_lower(dentry);
1073
	lower_inode = ecryptfs_inode_to_lower(inode);
1074
	if (!(lower_inode->i_opflags & IOP_XATTR)) {
1075
		rc = -EOPNOTSUPP;
1076 1077
		goto out;
	}
1078
	inode_lock(lower_inode);
1079
	rc = __vfs_removexattr(lower_dentry, name);
1080
	inode_unlock(lower_inode);
1081 1082 1083 1084
out:
	return rc;
}

1085
const struct inode_operations ecryptfs_symlink_iops = {
1086
	.get_link = ecryptfs_get_link,
1087 1088
	.permission = ecryptfs_permission,
	.setattr = ecryptfs_setattr,
1089
	.getattr = ecryptfs_getattr_link,
1090 1091 1092
	.listxattr = ecryptfs_listxattr,
};

1093
const struct inode_operations ecryptfs_dir_iops = {
1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107
	.create = ecryptfs_create,
	.lookup = ecryptfs_lookup,
	.link = ecryptfs_link,
	.unlink = ecryptfs_unlink,
	.symlink = ecryptfs_symlink,
	.mkdir = ecryptfs_mkdir,
	.rmdir = ecryptfs_rmdir,
	.mknod = ecryptfs_mknod,
	.rename = ecryptfs_rename,
	.permission = ecryptfs_permission,
	.setattr = ecryptfs_setattr,
	.listxattr = ecryptfs_listxattr,
};

1108
const struct inode_operations ecryptfs_main_iops = {
1109 1110
	.permission = ecryptfs_permission,
	.setattr = ecryptfs_setattr,
1111
	.getattr = ecryptfs_getattr,
1112
	.listxattr = ecryptfs_listxattr,
1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143
};

static int ecryptfs_xattr_get(const struct xattr_handler *handler,
			      struct dentry *dentry, struct inode *inode,
			      const char *name, void *buffer, size_t size)
{
	return ecryptfs_getxattr(dentry, inode, name, buffer, size);
}

static int ecryptfs_xattr_set(const struct xattr_handler *handler,
			      struct dentry *dentry, struct inode *inode,
			      const char *name, const void *value, size_t size,
			      int flags)
{
	if (value)
		return ecryptfs_setxattr(dentry, inode, name, value, size, flags);
	else {
		BUG_ON(flags != XATTR_REPLACE);
		return ecryptfs_removexattr(dentry, inode, name);
	}
}

const struct xattr_handler ecryptfs_xattr_handler = {
	.prefix = "",  /* match anything */
	.get = ecryptfs_xattr_get,
	.set = ecryptfs_xattr_set,
};

const struct xattr_handler *ecryptfs_xattr_handlers[] = {
	&ecryptfs_xattr_handler,
	NULL
1144
};