summaryrefslogtreecommitdiffstats
path: root/fs/ecryptfs/main.c
blob: 8876fe7c76e28e2be30f87d5f478ff0de885785e (plain)
1
2
3
4
5
6
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
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
/**
 * eCryptfs: Linux filesystem encryption layer
 *
 * Copyright (C) 1997-2003 Erez Zadok
 * Copyright (C) 2001-2003 Stony Brook University
 * Copyright (C) 2004-2007 International Business Machines Corp.
 *   Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
 *              Michael C. Thompson <mcthomps@us.ibm.com>
 *              Tyler Hicks <tyhicks@ou.edu>
 *
 * 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/dcache.h>
#include <linux/file.h>
#include <linux/module.h>
#include <linux/namei.h>
#include <linux/skbuff.h>
#include <linux/crypto.h>
#include <linux/netlink.h>
#include <linux/mount.h>
#include <linux/pagemap.h>
#include <linux/key.h>
#include <linux/parser.h>
#include <linux/fs_stack.h>
#include "ecryptfs_kernel.h"

/**
 * Module parameter that defines the ecryptfs_verbosity level.
 */
int ecryptfs_verbosity = 0;

module_param(ecryptfs_verbosity, int, 0);
MODULE_PARM_DESC(ecryptfs_verbosity,
		 "Initial verbosity level (0 or 1; defaults to "
		 "0, which is Quiet)");

/**
 * Module parameter that defines the number of netlink message buffer
 * elements
 */
unsigned int ecryptfs_message_buf_len = ECRYPTFS_DEFAULT_MSG_CTX_ELEMS;

module_param(ecryptfs_message_buf_len, uint, 0);
MODULE_PARM_DESC(ecryptfs_message_buf_len,
		 "Number of message buffer elements");

/**
 * Module parameter that defines the maximum guaranteed amount of time to wait
 * for a response through netlink.  The actual sleep time will be, more than
 * likely, a small amount greater than this specified value, but only less if
 * the netlink message successfully arrives.
 */
signed long ecryptfs_message_wait_timeout = ECRYPTFS_MAX_MSG_CTX_TTL / HZ;

module_param(ecryptfs_message_wait_timeout, long, 0);
MODULE_PARM_DESC(ecryptfs_message_wait_timeout,
		 "Maximum number of seconds that an operation will "
		 "sleep while waiting for a message response from "
		 "userspace");

/**
 * Module parameter that is an estimate of the maximum number of users
 * that will be concurrently using eCryptfs. Set this to the right
 * value to balance performance and memory use.
 */
unsigned int ecryptfs_number_of_users = ECRYPTFS_DEFAULT_NUM_USERS;

module_param(ecryptfs_number_of_users, uint, 0);
MODULE_PARM_DESC(ecryptfs_number_of_users, "An estimate of the number of "
		 "concurrent users of eCryptfs");

unsigned int ecryptfs_transport = ECRYPTFS_DEFAULT_TRANSPORT;

void __ecryptfs_printk(const char *fmt, ...)
{
	va_list args;
	va_start(args, fmt);
	if (fmt[1] == '7') { /* KERN_DEBUG */
		if (ecryptfs_verbosity >= 1)
			vprintk(fmt, args);
	} else
		vprintk(fmt, args);
	va_end(args);
}

/**
 * ecryptfs_init_persistent_file
 * @ecryptfs_dentry: Fully initialized eCryptfs dentry object, with
 *                   the lower dentry and the lower mount set
 *
 * eCryptfs only ever keeps a single open file for every lower
 * inode. All I/O operations to the lower inode occur through that
 * file. When the first eCryptfs dentry that interposes with the first
 * lower dentry for that inode is created, this function creates the
 * persistent file struct and associates it with the eCryptfs
 * inode. When the eCryptfs inode is destroyed, the file is closed.
 *
 * The persistent file will be opened with read/write permissions, if
 * possible. Otherwise, it is opened read-only.
 *
 * This function does nothing if a lower persistent file is already
 * associated with the eCryptfs inode.
 *
 * Returns zero on success; non-zero otherwise
 */
static int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry)
{
	struct ecryptfs_inode_info *inode_info =
		ecryptfs_inode_to_private(ecryptfs_dentry->d_inode);
	int rc = 0;

	mutex_lock(&inode_info->lower_file_mutex);
	if (!inode_info->lower_file) {
		struct dentry *lower_dentry;
		struct vfsmount *lower_mnt =
			ecryptfs_dentry_to_lower_mnt(ecryptfs_dentry);

		lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
		rc = ecryptfs_privileged_open(&inode_info->lower_file,
						     lower_dentry, lower_mnt);
		if (rc || IS_ERR(inode_info->lower_file)) {
			printk(KERN_ERR "Error opening lower persistent file "
			       "for lower_dentry [0x%p] and lower_mnt [0x%p]; "
			       "rc = [%d]\n", lower_dentry, lower_mnt, rc);
			rc = PTR_ERR(inode_info->lower_file);
			inode_info->lower_file = NULL;
		}
	}
	mutex_unlock(&inode_info->lower_file_mutex);
	return rc;
}

/**
 * ecryptfs_interpose
 * @lower_dentry: Existing dentry in the lower filesystem
 * @dentry: ecryptfs' dentry
 * @sb: ecryptfs's super_block
 * @flag: If set to true, then d_add is called, else d_instantiate is called
 *
 * Interposes upper and lower dentries.
 *
 * Returns zero on success; non-zero otherwise
 */
int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry,
		       struct super_block *sb, int flag)
{
	struct inode *lower_inode;
	struct inode *inode;
	int rc = 0;

	lower_inode = lower_dentry->d_inode;
	if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb)) {
		rc = -EXDEV;
		goto out;
	}
	if (!igrab(lower_inode)) {
		rc = -ESTALE;
		goto out;
	}
	inode = iget5_locked(sb, (unsigned long)lower_inode,
			     ecryptfs_inode_test, ecryptfs_inode_set,
			     lower_inode);
	if (!inode) {
		rc = -EACCES;
		iput(lower_inode);
		goto out;
	}
	if (inode->i_state & I_NEW)
		unlock_new_inode(inode);
	else
		iput(lower_inode);
	if (S_ISLNK(lower_inode->i_mode))
		inode->i_op = &ecryptfs_symlink_iops;
	else if (S_ISDIR(lower_inode->i_mode))
		inode->i_op = &ecryptfs_dir_iops;
	if (S_ISDIR(lower_inode->i_mode))
		inode->i_fop = &ecryptfs_dir_fops;
	if (special_file(lower_inode->i_mode))
		init_special_inode(inode, lower_inode->i_mode,
				   lower_inode->i_rdev);
	dentry->d_op = &ecryptfs_dops;
	if (flag)
		d_add(dentry, inode);
	else
		d_instantiate(dentry, inode);
	fsstack_copy_attr_all(inode, lower_inode, NULL);
	/* This size will be overwritten for real files w/ headers and
	 * other metadata */
	fsstack_copy_inode_size(inode, lower_inode);
	rc = ecryptfs_init_persistent_file(dentry);
	if (rc) {
		printk(KERN_ERR "%s: Error attempting to initialize the "
		       "persistent file for the dentry with name [%s]; "
		       "rc = [%d]\n", __func__, dentry->d_name.name, rc);
		goto out;
	}
out:
	return rc;
}

enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig,
       ecryptfs_opt_cipher, ecryptfs_opt_ecryptfs_cipher,
       ecryptfs_opt_ecryptfs_key_bytes,
       ecryptfs_opt_passthrough, ecryptfs_opt_xattr_metadata,
       ecryptfs_opt_encrypted_view, ecryptfs_opt_err };

static match_table_t tokens = {
	{ecryptfs_opt_sig, "sig=%s"},
	{ecryptfs_opt_ecryptfs_sig, "ecryptfs_sig=%s"},
	{ecryptfs_opt_cipher, "cipher=%s"},
	{ecryptfs_opt_ecryptfs_cipher, "ecryptfs_cipher=%s"},
	{ecryptfs_opt_ecryptfs_key_bytes, "ecryptfs_key_bytes=%u"},
	{ecryptfs_opt_passthrough, "ecryptfs_passthrough"},
	{ecryptfs_opt_xattr_metadata, "ecryptfs_xattr_metadata"},
	{ecryptfs_opt_encrypted_view, "ecryptfs_encrypted_view"},
	{ecryptfs_opt_err, NULL}
};

static int ecryptfs_init_global_auth_toks(
	struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
{
	struct ecryptfs_global_auth_tok *global_auth_tok;
	int rc = 0;

	list_for_each_entry(global_auth_tok,
			    &mount_crypt_stat->global_auth_tok_list,
			    mount_crypt_stat_list) {
		rc = ecryptfs_keyring_auth_tok_for_sig(
			&global_auth_tok->global_auth_tok_key,
			&global_auth_tok->global_auth_tok,
			global_auth_tok->sig);
		if (rc) {
			printk(KERN_ERR "Could not find valid key in user "
			       "session keyring for sig specified in mount "
			       "option: [%s]\n", global_auth_tok->sig);
			global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID;
			goto out;
		} else
			global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID;
	}
out:
	return rc;
}

static void ecryptfs_init_mount_crypt_stat(
	struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
{
	memset((void *)mount_crypt_stat, 0,
	       sizeof(struct ecryptfs_mount_crypt_stat));
	INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list);
	mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex);
	mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED;
}

/**
 * ecryptfs_parse_options
 * @sb: The ecryptfs super block
 * @options: The options pased to the kernel
 *
 * Parse mount options:
 * debug=N 	   - ecryptfs_verbosity level for debug output
 * sig=XXX	   - description(signature) of the key to use
 *
 * Returns the dentry object of the lower-level (lower/interposed)
 * directory; We want to mount our stackable file system on top of
 * that lower directory.
 *
 * The signature of the key to use must be the description of a key
 * already in the keyring. Mounting will fail if the key can not be
 * found.
 *
 * Returns zero on success; non-zero on error
 */
static int ecryptfs_parse_options(struct super_block *sb, char *options)
{
	char *p;
	int rc = 0;
	int sig_set = 0;
	int cipher_name_set = 0;
	int cipher_key_bytes;
	int cipher_key_bytes_set = 0;
	struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
		&ecryptfs_superblock_to_private(sb)->mount_crypt_stat;
	substring_t args[MAX_OPT_ARGS];
	int token;
	char *sig_src;
	char *cipher_name_dst;
	char *cipher_name_src;
	char *cipher_key_bytes_src;
	int cipher_name_len;

	if (!options) {
		rc = -EINVAL;
		goto out;
	}
	ecryptfs_init_mount_crypt_stat(mount_crypt_stat);
	while ((p = strsep(&options, ",")) != NULL) {
		if (!*p)
			continue;
		token = match_token(p, tokens, args);
		switch (token) {
		case ecryptfs_opt_sig:
		case ecryptfs_opt_ecryptfs_sig:
			sig_src = args[0].from;
			rc = ecryptfs_add_global_auth_tok(mount_crypt_stat,
							  sig_src);
			if (rc) {
				printk(KERN_ERR "Error attempting to register "
				       "global sig; rc = [%d]\n", rc);
				goto out;
			}
			sig_set = 1;
			break;
		case ecryptfs_opt_cipher:
		case ecryptfs_opt_ecryptfs_cipher:
			cipher_name_src = args[0].from;
			cipher_name_dst =
				mount_crypt_stat->
				global_default_cipher_name;
			strncpy(cipher_name_dst, cipher_name_src,
				ECRYPTFS_MAX_CIPHER_NAME_SIZE);
			ecryptfs_printk(KERN_DEBUG,
					"The mount_crypt_stat "
					"global_default_cipher_name set to: "
					"[%s]\n", cipher_name_dst);
			cipher_name_set = 1;
			break;
		case ecryptfs_opt_ecryptfs_key_bytes:
			cipher_key_bytes_src = args[0].from;
			cipher_key_bytes =
				(int)simple_strtol(cipher_key_bytes_src,
						   &cipher_key_bytes_src, 0);
			mount_crypt_stat->global_default_cipher_key_size =
				cipher_key_bytes;
			ecryptfs_printk(KERN_DEBUG,
					"The mount_crypt_stat "
					"global_default_cipher_key_size "
					"set to: [%d]\n", mount_crypt_stat->
					global_default_cipher_key_size);
			cipher_key_bytes_set = 1;
			break;
		case ecryptfs_opt_passthrough:
			mount_crypt_stat->flags |=
				ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED;
			break;
		case ecryptfs_opt_xattr_metadata:
			mount_crypt_stat->flags |=
				ECRYPTFS_XATTR_METADATA_ENABLED;
			break;
		case ecryptfs_opt_encrypted_view:
			mount_crypt_stat->flags |=
				ECRYPTFS_XATTR_METADATA_ENABLED;
			mount_crypt_stat->flags |=
				ECRYPTFS_ENCRYPTED_VIEW_ENABLED;
			break;
		case ecryptfs_opt_err:
		default:
			ecryptfs_printk(KERN_WARNING,
					"eCryptfs: unrecognized option '%s'\n",
					p);
		}
	}
	if (!sig_set) {
		rc = -EINVAL;
		ecryptfs_printk(KERN_ERR, "You must supply at least one valid "
				"auth tok signature as a mount "
				"parameter; see the eCryptfs README\n");
		goto out;
	}
	if (!cipher_name_set) {
		cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER);
		if (unlikely(cipher_name_len
			     >= ECRYPTFS_MAX_CIPHER_NAME_SIZE)) {
			rc = -EINVAL;
			BUG();
			goto out;
		}
		memcpy(mount_crypt_stat->global_default_cipher_name,
		       ECRYPTFS_DEFAULT_CIPHER, cipher_name_len);
		mount_crypt_stat->global_default_cipher_name[cipher_name_len]
		    = '\0';
	}
	if (!cipher_key_bytes_set) {
		mount_crypt_stat->global_default_cipher_key_size = 0;
	}
	mutex_lock(&key_tfm_list_mutex);
	if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name,
				 NULL))
		rc = ecryptfs_add_new_key_tfm(
			NULL, mount_crypt_stat->global_default_cipher_name,
			mount_crypt_stat->global_default_cipher_key_size);
	mutex_unlock(&key_tfm_list_mutex);
	if (rc) {
		printk(KERN_ERR "Error attempting to initialize cipher with "
		       "name = [%s] and key size = [%td]; rc = [%d]\n",
		       mount_crypt_stat->global_default_cipher_name,
		       mount_crypt_stat->global_default_cipher_key_size, rc);
		rc = -EINVAL;
		goto out;
	}
	rc = ecryptfs_init_global_auth_toks(mount_crypt_stat);
	if (rc) {
		printk(KERN_WARNING "One or more global auth toks could not "
		       "properly register; rc = [%d]\n", rc);
	}
out:
	return rc;
}

struct kmem_cache *ecryptfs_sb_info_cache;

/**
 * ecryptfs_fill_super
 * @sb: The ecryptfs super block
 * @raw_data: The options passed to mount
 * @silent: Not used but required by function prototype
 *
 * Sets up what we can of the sb, rest is done in ecryptfs_read_super
 *
 * Returns zero on success; non-zero otherwise
 */
static int
ecryptfs_fill_super(struct super_block *sb, void *raw_data, int silent)
{
	int rc = 0;

	/* Released in ecryptfs_put_super() */
	ecryptfs_set_superblock_private(sb,
					kmem_cache_zalloc(ecryptfs_sb_info_cache,
							 GFP_KERNEL));
	if (!ecryptfs_superblock_to_private(sb)) {
		ecryptfs_printk(KERN_WARNING, "Out of memory\n");
		rc = -ENOMEM;
		goto out;
	}
	sb->s_op = &ecryptfs_sops;
	/* Released through deactivate_super(sb) from get_sb_nodev */
	sb->s_root = d_alloc(NULL, &(const struct qstr) {
			     .hash = 0,.name = "/",.len = 1});
	if (!sb->s_root) {
		ecryptfs_printk(KERN_ERR, "d_alloc failed\n");
		rc = -ENOMEM;
		goto out;
	}
	sb->s_root->d_op = &ecryptfs_dops;
	sb->s_root->d_sb = sb;
	sb->s_root->d_parent = sb->s_root;
	/* Released in d_release when dput(sb->s_root) is called */
	/* through deactivate_super(sb) from get_sb_nodev() */
	ecryptfs_set_dentry_private(sb->s_root,
				    kmem_cache_zalloc(ecryptfs_dentry_info_cache,
						     GFP_KERNEL));
	if (!ecryptfs_dentry_to_private(sb->s_root)) {
		ecryptfs_printk(KERN_ERR,
				"dentry_info_cache alloc failed\n");
		rc = -ENOMEM;
		goto out;
	}
	rc = 0;
out:
	/* Should be able to rely on deactivate_super called from
	 * get_sb_nodev */
	return rc;
}

/**
 * ecryptfs_read_super
 * @sb: The ecryptfs super block
 * @dev_name: The path to mount over
 *
 * Read the super block of the lower filesystem, and use
 * ecryptfs_interpose to create our initial inode and super block
 * struct.
 */
static int ecryptfs_read_super(struct super_block *sb, const char *dev_name)
{
	int rc;
	struct nameidata nd;
	struct dentry *lower_root;
	struct vfsmount *lower_mnt;

	memset(&nd, 0, sizeof(struct nameidata));
	rc = path_lookup(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &nd);
	if (rc) {
		ecryptfs_printk(KERN_WARNING, "path_lookup() failed\n");
		goto out;
	}
	lower_root = nd.path.dentry;
	lower_mnt = nd.path.mnt;
	ecryptfs_set_superblock_lower(sb, lower_root->d_sb);
	sb->s_maxbytes = lower_root->d_sb->s_maxbytes;
	sb->s_blocksize = lower_root->d_sb->s_blocksize;
	ecryptfs_set_dentry_lower(sb->s_root, lower_root);
	ecryptfs_set_dentry_lower_mnt(sb->s_root, lower_mnt);
	rc = ecryptfs_interpose(lower_root, sb->s_root, sb, 0);
	if (rc)
		goto out_free;
	rc = 0;
	goto out;
out_free:
	path_put(&nd.path);
out:
	return rc;
}

/**
 * ecryptfs_get_sb
 * @fs_type
 * @flags
 * @dev_name: The path to mount over
 * @raw_data: The options passed into the kernel
 *
 * The whole ecryptfs_get_sb process is broken into 4 functions:
 * ecryptfs_parse_options(): handle options passed to ecryptfs, if any
 * ecryptfs_fill_super(): used by get_sb_nodev, fills out the super_block
 *                        with as much information as it can before needing
 *                        the lower filesystem.
 * ecryptfs_read_super(): this accesses the lower filesystem and uses
 *                        ecryptfs_interpolate to perform most of the linking
 * ecryptfs_interpolate(): links the lower filesystem into ecryptfs
 */
static int ecryptfs_get_sb(struct file_system_type *fs_type, int flags,
			const char *dev_name, void *raw_data,
			struct vfsmount *mnt)
{
	int rc;
	struct super_block *sb;

	rc = get_sb_nodev(fs_type, flags, raw_data, ecryptfs_fill_super, mnt);
	if (rc < 0) {
		printk(KERN_ERR "Getting sb failed; rc = [%d]\n", rc);
		goto out;
	}
	sb = mnt->mnt_sb;
	rc = ecryptfs_parse_options(sb, raw_data);
	if (rc) {
		printk(KERN_ERR "Error parsing options; rc = [%d]\n", rc);
		goto out_abort;
	}
	rc = ecryptfs_read_super(sb, dev_name);
	if (rc) {
		printk(KERN_ERR "Reading sb failed; rc = [%d]\n", rc);
		goto out_abort;
	}
	goto out;
out_abort:
	dput(sb->s_root);
	up_write(&sb->s_umount);
	deactivate_super(sb);
out:
	return rc;
}

/**
 * ecryptfs_kill_block_super
 * @sb: The ecryptfs super block
 *
 * Used to bring the superblock down and free the private data.
 * Private data is free'd in ecryptfs_put_super()
 */
static void ecryptfs_kill_block_super(struct super_block *sb)
{
	generic_shutdown_super(sb);
}

static struct file_system_type ecryptfs_fs_type = {
	.owner = THIS_MODULE,
	.name = "ecryptfs",
	.get_sb = ecryptfs_get_sb,
	.kill_sb = ecryptfs_kill_block_super,
	.fs_flags = 0
};

/**
 * inode_info_init_once
 *
 * Initializes the ecryptfs_inode_info_cache when it is created
 */
static void
inode_info_init_once(struct kmem_cache *cachep, void *vptr)
{
	struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr;

	inode_init_once(&ei->vfs_inode);
}

static struct ecryptfs_cache_info {
	struct kmem_cache **cache;
	const char *name;
	size_t size;
	void (*ctor)(struct kmem_cache *cache, void *obj);
} ecryptfs_cache_infos[] = {
	{
		.cache = &ecryptfs_auth_tok_list_item_cache,
		.name = "ecryptfs_auth_tok_list_item",
		.size = sizeof(struct ecryptfs_auth_tok_list_item),
	},
	{
		.cache = &ecryptfs_file_info_cache,
		.name = "ecryptfs_file_cache",
		.size = sizeof(struct ecryptfs_file_info),
	},
	{
		.cache = &ecryptfs_dentry_info_cache,
		.name = "ecryptfs_dentry_info_cache",
		.size = sizeof(struct ecryptfs_dentry_info),
	},
	{
		.cache = &ecryptfs_inode_info_cache,
		.name = "ecryptfs_inode_cache",
		.size = sizeof(struct ecryptfs_inode_info),
		.ctor = inode_info_init_once,
	},
	{
		.cache = &ecryptfs_sb_info_cache,
		.name = "ecryptfs_sb_cache",
		.size = sizeof(struct ecryptfs_sb_info),
	},
	{
		.cache = &ecryptfs_header_cache_1,
		.name = "ecryptfs_headers_1",
		.size = PAGE_CACHE_SIZE,
	},
	{
		.cache = &ecryptfs_header_cache_2,
		.name = "ecryptfs_headers_2",
		.size = PAGE_CACHE_SIZE,
	},
	{
		.cache = &ecryptfs_xattr_cache,
		.name = "ecryptfs_xattr_cache",
		.size = PAGE_CACHE_SIZE,
	},
	{
		.cache = &ecryptfs_key_record_cache,
		.name = "ecryptfs_key_record_cache",
		.size = sizeof(struct ecryptfs_key_record),
	},
	{
		.cache = &ecryptfs_key_sig_cache,
		.name = "ecryptfs_key_sig_cache",
		.size = sizeof(struct ecryptfs_key_sig),
	},
	{
		.cache = &ecryptfs_global_auth_tok_cache,
		.name = "ecryptfs_global_auth_tok_cache",
		.size = sizeof(struct ecryptfs_global_auth_tok),
	},
	{
		.cache = &ecryptfs_key_tfm_cache,
		.name = "ecryptfs_key_tfm_cache",
		.size = sizeof(struct ecryptfs_key_tfm),
	},
	{
		.cache = &ecryptfs_open_req_cache,
		.name = "ecryptfs_open_req_cache",
		.size = sizeof(struct ecryptfs_open_req),
	},
};

static void ecryptfs_free_kmem_caches(void)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
		struct ecryptfs_cache_info *info;

		info = &ecryptfs_cache_infos[i];
		if (*(info->cache))
			kmem_cache_destroy(*(info->cache));
	}
}

/**
 * ecryptfs_init_kmem_caches
 *
 * Returns zero on success; non-zero otherwise
 */
static int ecryptfs_init_kmem_caches(void)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
		struct ecryptfs_cache_info *info;

		info = &ecryptfs_cache_infos[i];
		*(info->cache) = kmem_cache_create(info->name, info->size,
				0, SLAB_HWCACHE_ALIGN, info->ctor);
		if (!*(info->cache)) {
			ecryptfs_free_kmem_caches();
			ecryptfs_printk(KERN_WARNING, "%s: "
					"kmem_cache_create failed\n",
					info->name);
			return -ENOMEM;
		}
	}
	return 0;
}

static struct kobject *ecryptfs_kobj;

static ssize_t version_show(struct kobject *kobj,
			    struct kobj_attribute *attr, char *buff)
{
	return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK);
}

static struct kobj_attribute version_attr = __ATTR_RO(version);

static struct attribute *attributes[] = {
	&version_attr.attr,
	NULL,
};

static struct attribute_group attr_group = {
	.attrs = attributes,
};

static int do_sysfs_registration(void)
{
	int rc;

	ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj);
	if (!ecryptfs_kobj) {
		printk(KERN_ERR "Unable to create ecryptfs kset\n");
		rc = -ENOMEM;
		goto out;
	}
	rc = sysfs_create_group(ecryptfs_kobj, &attr_group);
	if (rc) {
		printk(KERN_ERR
		       "Unable to create ecryptfs version attributes\n");
		kobject_put(ecryptfs_kobj);
	}
out:
	return rc;
}

static void do_sysfs_unregistration(void)
{
	sysfs_remove_group(ecryptfs_kobj, &attr_group);
	kobject_put(ecryptfs_kobj);
}

static int __init ecryptfs_init(void)
{
	int rc;

	if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_CACHE_SIZE) {
		rc = -EINVAL;
		ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is "
				"larger than the host's page size, and so "
				"eCryptfs cannot run on this system. The "
				"default eCryptfs extent size is [%d] bytes; "
				"the page size is [%d] bytes.\n",
				ECRYPTFS_DEFAULT_EXTENT_SIZE, PAGE_CACHE_SIZE);
		goto out;
	}
	rc = ecryptfs_init_kmem_caches();
	if (rc) {
		printk(KERN_ERR
		       "Failed to allocate one or more kmem_cache objects\n");
		goto out;
	}
	rc = register_filesystem(&ecryptfs_fs_type);
	if (rc) {
		printk(KERN_ERR "Failed to register filesystem\n");
		goto out_free_kmem_caches;
	}
	rc = do_sysfs_registration();
	if (rc) {
		printk(KERN_ERR "sysfs registration failed\n");
		goto out_unregister_filesystem;
	}
	rc = ecryptfs_init_kthread();
	if (rc) {
		printk(KERN_ERR "%s: kthread initialization failed; "
		       "rc = [%d]\n", __func__, rc);
		goto out_do_sysfs_unregistration;
	}
	rc = ecryptfs_init_messaging(ecryptfs_transport);
	if (rc) {
		printk(KERN_ERR "Failure occured while attempting to "
				"initialize the eCryptfs netlink socket\n");
		goto out_destroy_kthread;
	}
	rc = ecryptfs_init_crypto();
	if (rc) {
		printk(KERN_ERR "Failure whilst attempting to init crypto; "
		       "rc = [%d]\n", rc);
		goto out_release_messaging;
	}
	if (ecryptfs_verbosity > 0)
		printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values "
			"will be written to the syslog!\n", ecryptfs_verbosity);

	goto out;
out_release_messaging:
	ecryptfs_release_messaging(ecryptfs_transport);
out_destroy_kthread:
	ecryptfs_destroy_kthread();
out_do_sysfs_unregistration:
	do_sysfs_unregistration();
out_unregister_filesystem:
	unregister_filesystem(&ecryptfs_fs_type);
out_free_kmem_caches:
	ecryptfs_free_kmem_caches();
out:
	return rc;
}

static void __exit ecryptfs_exit(void)
{
	int rc;

	rc = ecryptfs_destroy_crypto();
	if (rc)
		printk(KERN_ERR "Failure whilst attempting to destroy crypto; "
		       "rc = [%d]\n", rc);
	ecryptfs_release_messaging(ecryptfs_transport);
	ecryptfs_destroy_kthread();
	do_sysfs_unregistration();
	unregister_filesystem(&ecryptfs_fs_type);
	ecryptfs_free_kmem_caches();
}

MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>");
MODULE_DESCRIPTION("eCryptfs");

MODULE_LICENSE("GPL");

module_init(ecryptfs_init)
module_exit(ecryptfs_exit)
OpenPOWER on IntegriCloud