xref: /openbmc/linux/fs/ecryptfs/main.c (revision 545e4006)
1 /**
2  * eCryptfs: Linux filesystem encryption layer
3  *
4  * Copyright (C) 1997-2003 Erez Zadok
5  * Copyright (C) 2001-2003 Stony Brook University
6  * Copyright (C) 2004-2007 International Business Machines Corp.
7  *   Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
8  *              Michael C. Thompson <mcthomps@us.ibm.com>
9  *              Tyler Hicks <tyhicks@ou.edu>
10  *
11  * This program is free software; you can redistribute it and/or
12  * modify it under the terms of the GNU General Public License as
13  * published by the Free Software Foundation; either version 2 of the
14  * License, or (at your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful, but
17  * WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
19  * General Public License for more details.
20  *
21  * You should have received a copy of the GNU General Public License
22  * along with this program; if not, write to the Free Software
23  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
24  * 02111-1307, USA.
25  */
26 
27 #include <linux/dcache.h>
28 #include <linux/file.h>
29 #include <linux/module.h>
30 #include <linux/namei.h>
31 #include <linux/skbuff.h>
32 #include <linux/crypto.h>
33 #include <linux/netlink.h>
34 #include <linux/mount.h>
35 #include <linux/pagemap.h>
36 #include <linux/key.h>
37 #include <linux/parser.h>
38 #include <linux/fs_stack.h>
39 #include "ecryptfs_kernel.h"
40 
41 /**
42  * Module parameter that defines the ecryptfs_verbosity level.
43  */
44 int ecryptfs_verbosity = 0;
45 
46 module_param(ecryptfs_verbosity, int, 0);
47 MODULE_PARM_DESC(ecryptfs_verbosity,
48 		 "Initial verbosity level (0 or 1; defaults to "
49 		 "0, which is Quiet)");
50 
51 /**
52  * Module parameter that defines the number of netlink message buffer
53  * elements
54  */
55 unsigned int ecryptfs_message_buf_len = ECRYPTFS_DEFAULT_MSG_CTX_ELEMS;
56 
57 module_param(ecryptfs_message_buf_len, uint, 0);
58 MODULE_PARM_DESC(ecryptfs_message_buf_len,
59 		 "Number of message buffer elements");
60 
61 /**
62  * Module parameter that defines the maximum guaranteed amount of time to wait
63  * for a response through netlink.  The actual sleep time will be, more than
64  * likely, a small amount greater than this specified value, but only less if
65  * the netlink message successfully arrives.
66  */
67 signed long ecryptfs_message_wait_timeout = ECRYPTFS_MAX_MSG_CTX_TTL / HZ;
68 
69 module_param(ecryptfs_message_wait_timeout, long, 0);
70 MODULE_PARM_DESC(ecryptfs_message_wait_timeout,
71 		 "Maximum number of seconds that an operation will "
72 		 "sleep while waiting for a message response from "
73 		 "userspace");
74 
75 /**
76  * Module parameter that is an estimate of the maximum number of users
77  * that will be concurrently using eCryptfs. Set this to the right
78  * value to balance performance and memory use.
79  */
80 unsigned int ecryptfs_number_of_users = ECRYPTFS_DEFAULT_NUM_USERS;
81 
82 module_param(ecryptfs_number_of_users, uint, 0);
83 MODULE_PARM_DESC(ecryptfs_number_of_users, "An estimate of the number of "
84 		 "concurrent users of eCryptfs");
85 
86 unsigned int ecryptfs_transport = ECRYPTFS_DEFAULT_TRANSPORT;
87 
88 void __ecryptfs_printk(const char *fmt, ...)
89 {
90 	va_list args;
91 	va_start(args, fmt);
92 	if (fmt[1] == '7') { /* KERN_DEBUG */
93 		if (ecryptfs_verbosity >= 1)
94 			vprintk(fmt, args);
95 	} else
96 		vprintk(fmt, args);
97 	va_end(args);
98 }
99 
100 /**
101  * ecryptfs_init_persistent_file
102  * @ecryptfs_dentry: Fully initialized eCryptfs dentry object, with
103  *                   the lower dentry and the lower mount set
104  *
105  * eCryptfs only ever keeps a single open file for every lower
106  * inode. All I/O operations to the lower inode occur through that
107  * file. When the first eCryptfs dentry that interposes with the first
108  * lower dentry for that inode is created, this function creates the
109  * persistent file struct and associates it with the eCryptfs
110  * inode. When the eCryptfs inode is destroyed, the file is closed.
111  *
112  * The persistent file will be opened with read/write permissions, if
113  * possible. Otherwise, it is opened read-only.
114  *
115  * This function does nothing if a lower persistent file is already
116  * associated with the eCryptfs inode.
117  *
118  * Returns zero on success; non-zero otherwise
119  */
120 int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry)
121 {
122 	struct ecryptfs_inode_info *inode_info =
123 		ecryptfs_inode_to_private(ecryptfs_dentry->d_inode);
124 	int rc = 0;
125 
126 	mutex_lock(&inode_info->lower_file_mutex);
127 	if (!inode_info->lower_file) {
128 		struct dentry *lower_dentry;
129 		struct vfsmount *lower_mnt =
130 			ecryptfs_dentry_to_lower_mnt(ecryptfs_dentry);
131 
132 		lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
133 		rc = ecryptfs_privileged_open(&inode_info->lower_file,
134 						     lower_dentry, lower_mnt);
135 		if (rc || IS_ERR(inode_info->lower_file)) {
136 			printk(KERN_ERR "Error opening lower persistent file "
137 			       "for lower_dentry [0x%p] and lower_mnt [0x%p]; "
138 			       "rc = [%d]\n", lower_dentry, lower_mnt, rc);
139 			rc = PTR_ERR(inode_info->lower_file);
140 			inode_info->lower_file = NULL;
141 		}
142 	}
143 	mutex_unlock(&inode_info->lower_file_mutex);
144 	return rc;
145 }
146 
147 /**
148  * ecryptfs_interpose
149  * @lower_dentry: Existing dentry in the lower filesystem
150  * @dentry: ecryptfs' dentry
151  * @sb: ecryptfs's super_block
152  * @flags: flags to govern behavior of interpose procedure
153  *
154  * Interposes upper and lower dentries.
155  *
156  * Returns zero on success; non-zero otherwise
157  */
158 int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry,
159 		       struct super_block *sb, u32 flags)
160 {
161 	struct inode *lower_inode;
162 	struct inode *inode;
163 	int rc = 0;
164 
165 	lower_inode = lower_dentry->d_inode;
166 	if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb)) {
167 		rc = -EXDEV;
168 		goto out;
169 	}
170 	if (!igrab(lower_inode)) {
171 		rc = -ESTALE;
172 		goto out;
173 	}
174 	inode = iget5_locked(sb, (unsigned long)lower_inode,
175 			     ecryptfs_inode_test, ecryptfs_inode_set,
176 			     lower_inode);
177 	if (!inode) {
178 		rc = -EACCES;
179 		iput(lower_inode);
180 		goto out;
181 	}
182 	if (inode->i_state & I_NEW)
183 		unlock_new_inode(inode);
184 	else
185 		iput(lower_inode);
186 	if (S_ISLNK(lower_inode->i_mode))
187 		inode->i_op = &ecryptfs_symlink_iops;
188 	else if (S_ISDIR(lower_inode->i_mode))
189 		inode->i_op = &ecryptfs_dir_iops;
190 	if (S_ISDIR(lower_inode->i_mode))
191 		inode->i_fop = &ecryptfs_dir_fops;
192 	if (special_file(lower_inode->i_mode))
193 		init_special_inode(inode, lower_inode->i_mode,
194 				   lower_inode->i_rdev);
195 	dentry->d_op = &ecryptfs_dops;
196 	if (flags & ECRYPTFS_INTERPOSE_FLAG_D_ADD)
197 		d_add(dentry, inode);
198 	else
199 		d_instantiate(dentry, inode);
200 	fsstack_copy_attr_all(inode, lower_inode, NULL);
201 	/* This size will be overwritten for real files w/ headers and
202 	 * other metadata */
203 	fsstack_copy_inode_size(inode, lower_inode);
204 out:
205 	return rc;
206 }
207 
208 enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig,
209        ecryptfs_opt_cipher, ecryptfs_opt_ecryptfs_cipher,
210        ecryptfs_opt_ecryptfs_key_bytes,
211        ecryptfs_opt_passthrough, ecryptfs_opt_xattr_metadata,
212        ecryptfs_opt_encrypted_view, ecryptfs_opt_err };
213 
214 static match_table_t tokens = {
215 	{ecryptfs_opt_sig, "sig=%s"},
216 	{ecryptfs_opt_ecryptfs_sig, "ecryptfs_sig=%s"},
217 	{ecryptfs_opt_cipher, "cipher=%s"},
218 	{ecryptfs_opt_ecryptfs_cipher, "ecryptfs_cipher=%s"},
219 	{ecryptfs_opt_ecryptfs_key_bytes, "ecryptfs_key_bytes=%u"},
220 	{ecryptfs_opt_passthrough, "ecryptfs_passthrough"},
221 	{ecryptfs_opt_xattr_metadata, "ecryptfs_xattr_metadata"},
222 	{ecryptfs_opt_encrypted_view, "ecryptfs_encrypted_view"},
223 	{ecryptfs_opt_err, NULL}
224 };
225 
226 static int ecryptfs_init_global_auth_toks(
227 	struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
228 {
229 	struct ecryptfs_global_auth_tok *global_auth_tok;
230 	int rc = 0;
231 
232 	list_for_each_entry(global_auth_tok,
233 			    &mount_crypt_stat->global_auth_tok_list,
234 			    mount_crypt_stat_list) {
235 		rc = ecryptfs_keyring_auth_tok_for_sig(
236 			&global_auth_tok->global_auth_tok_key,
237 			&global_auth_tok->global_auth_tok,
238 			global_auth_tok->sig);
239 		if (rc) {
240 			printk(KERN_ERR "Could not find valid key in user "
241 			       "session keyring for sig specified in mount "
242 			       "option: [%s]\n", global_auth_tok->sig);
243 			global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID;
244 			goto out;
245 		} else
246 			global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID;
247 	}
248 out:
249 	return rc;
250 }
251 
252 static void ecryptfs_init_mount_crypt_stat(
253 	struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
254 {
255 	memset((void *)mount_crypt_stat, 0,
256 	       sizeof(struct ecryptfs_mount_crypt_stat));
257 	INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list);
258 	mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex);
259 	mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED;
260 }
261 
262 /**
263  * ecryptfs_parse_options
264  * @sb: The ecryptfs super block
265  * @options: The options pased to the kernel
266  *
267  * Parse mount options:
268  * debug=N 	   - ecryptfs_verbosity level for debug output
269  * sig=XXX	   - description(signature) of the key to use
270  *
271  * Returns the dentry object of the lower-level (lower/interposed)
272  * directory; We want to mount our stackable file system on top of
273  * that lower directory.
274  *
275  * The signature of the key to use must be the description of a key
276  * already in the keyring. Mounting will fail if the key can not be
277  * found.
278  *
279  * Returns zero on success; non-zero on error
280  */
281 static int ecryptfs_parse_options(struct super_block *sb, char *options)
282 {
283 	char *p;
284 	int rc = 0;
285 	int sig_set = 0;
286 	int cipher_name_set = 0;
287 	int cipher_key_bytes;
288 	int cipher_key_bytes_set = 0;
289 	struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
290 		&ecryptfs_superblock_to_private(sb)->mount_crypt_stat;
291 	substring_t args[MAX_OPT_ARGS];
292 	int token;
293 	char *sig_src;
294 	char *cipher_name_dst;
295 	char *cipher_name_src;
296 	char *cipher_key_bytes_src;
297 
298 	if (!options) {
299 		rc = -EINVAL;
300 		goto out;
301 	}
302 	ecryptfs_init_mount_crypt_stat(mount_crypt_stat);
303 	while ((p = strsep(&options, ",")) != NULL) {
304 		if (!*p)
305 			continue;
306 		token = match_token(p, tokens, args);
307 		switch (token) {
308 		case ecryptfs_opt_sig:
309 		case ecryptfs_opt_ecryptfs_sig:
310 			sig_src = args[0].from;
311 			rc = ecryptfs_add_global_auth_tok(mount_crypt_stat,
312 							  sig_src);
313 			if (rc) {
314 				printk(KERN_ERR "Error attempting to register "
315 				       "global sig; rc = [%d]\n", rc);
316 				goto out;
317 			}
318 			sig_set = 1;
319 			break;
320 		case ecryptfs_opt_cipher:
321 		case ecryptfs_opt_ecryptfs_cipher:
322 			cipher_name_src = args[0].from;
323 			cipher_name_dst =
324 				mount_crypt_stat->
325 				global_default_cipher_name;
326 			strncpy(cipher_name_dst, cipher_name_src,
327 				ECRYPTFS_MAX_CIPHER_NAME_SIZE);
328 			ecryptfs_printk(KERN_DEBUG,
329 					"The mount_crypt_stat "
330 					"global_default_cipher_name set to: "
331 					"[%s]\n", cipher_name_dst);
332 			cipher_name_set = 1;
333 			break;
334 		case ecryptfs_opt_ecryptfs_key_bytes:
335 			cipher_key_bytes_src = args[0].from;
336 			cipher_key_bytes =
337 				(int)simple_strtol(cipher_key_bytes_src,
338 						   &cipher_key_bytes_src, 0);
339 			mount_crypt_stat->global_default_cipher_key_size =
340 				cipher_key_bytes;
341 			ecryptfs_printk(KERN_DEBUG,
342 					"The mount_crypt_stat "
343 					"global_default_cipher_key_size "
344 					"set to: [%d]\n", mount_crypt_stat->
345 					global_default_cipher_key_size);
346 			cipher_key_bytes_set = 1;
347 			break;
348 		case ecryptfs_opt_passthrough:
349 			mount_crypt_stat->flags |=
350 				ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED;
351 			break;
352 		case ecryptfs_opt_xattr_metadata:
353 			mount_crypt_stat->flags |=
354 				ECRYPTFS_XATTR_METADATA_ENABLED;
355 			break;
356 		case ecryptfs_opt_encrypted_view:
357 			mount_crypt_stat->flags |=
358 				ECRYPTFS_XATTR_METADATA_ENABLED;
359 			mount_crypt_stat->flags |=
360 				ECRYPTFS_ENCRYPTED_VIEW_ENABLED;
361 			break;
362 		case ecryptfs_opt_err:
363 		default:
364 			ecryptfs_printk(KERN_WARNING,
365 					"eCryptfs: unrecognized option '%s'\n",
366 					p);
367 		}
368 	}
369 	if (!sig_set) {
370 		rc = -EINVAL;
371 		ecryptfs_printk(KERN_ERR, "You must supply at least one valid "
372 				"auth tok signature as a mount "
373 				"parameter; see the eCryptfs README\n");
374 		goto out;
375 	}
376 	if (!cipher_name_set) {
377 		int cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER);
378 
379 		BUG_ON(cipher_name_len >= ECRYPTFS_MAX_CIPHER_NAME_SIZE);
380 
381 		strcpy(mount_crypt_stat->global_default_cipher_name,
382 		       ECRYPTFS_DEFAULT_CIPHER);
383 	}
384 	if (!cipher_key_bytes_set) {
385 		mount_crypt_stat->global_default_cipher_key_size = 0;
386 	}
387 	mutex_lock(&key_tfm_list_mutex);
388 	if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name,
389 				 NULL))
390 		rc = ecryptfs_add_new_key_tfm(
391 			NULL, mount_crypt_stat->global_default_cipher_name,
392 			mount_crypt_stat->global_default_cipher_key_size);
393 	mutex_unlock(&key_tfm_list_mutex);
394 	if (rc) {
395 		printk(KERN_ERR "Error attempting to initialize cipher with "
396 		       "name = [%s] and key size = [%td]; rc = [%d]\n",
397 		       mount_crypt_stat->global_default_cipher_name,
398 		       mount_crypt_stat->global_default_cipher_key_size, rc);
399 		rc = -EINVAL;
400 		goto out;
401 	}
402 	rc = ecryptfs_init_global_auth_toks(mount_crypt_stat);
403 	if (rc) {
404 		printk(KERN_WARNING "One or more global auth toks could not "
405 		       "properly register; rc = [%d]\n", rc);
406 	}
407 out:
408 	return rc;
409 }
410 
411 struct kmem_cache *ecryptfs_sb_info_cache;
412 
413 /**
414  * ecryptfs_fill_super
415  * @sb: The ecryptfs super block
416  * @raw_data: The options passed to mount
417  * @silent: Not used but required by function prototype
418  *
419  * Sets up what we can of the sb, rest is done in ecryptfs_read_super
420  *
421  * Returns zero on success; non-zero otherwise
422  */
423 static int
424 ecryptfs_fill_super(struct super_block *sb, void *raw_data, int silent)
425 {
426 	int rc = 0;
427 
428 	/* Released in ecryptfs_put_super() */
429 	ecryptfs_set_superblock_private(sb,
430 					kmem_cache_zalloc(ecryptfs_sb_info_cache,
431 							 GFP_KERNEL));
432 	if (!ecryptfs_superblock_to_private(sb)) {
433 		ecryptfs_printk(KERN_WARNING, "Out of memory\n");
434 		rc = -ENOMEM;
435 		goto out;
436 	}
437 	sb->s_op = &ecryptfs_sops;
438 	/* Released through deactivate_super(sb) from get_sb_nodev */
439 	sb->s_root = d_alloc(NULL, &(const struct qstr) {
440 			     .hash = 0,.name = "/",.len = 1});
441 	if (!sb->s_root) {
442 		ecryptfs_printk(KERN_ERR, "d_alloc failed\n");
443 		rc = -ENOMEM;
444 		goto out;
445 	}
446 	sb->s_root->d_op = &ecryptfs_dops;
447 	sb->s_root->d_sb = sb;
448 	sb->s_root->d_parent = sb->s_root;
449 	/* Released in d_release when dput(sb->s_root) is called */
450 	/* through deactivate_super(sb) from get_sb_nodev() */
451 	ecryptfs_set_dentry_private(sb->s_root,
452 				    kmem_cache_zalloc(ecryptfs_dentry_info_cache,
453 						     GFP_KERNEL));
454 	if (!ecryptfs_dentry_to_private(sb->s_root)) {
455 		ecryptfs_printk(KERN_ERR,
456 				"dentry_info_cache alloc failed\n");
457 		rc = -ENOMEM;
458 		goto out;
459 	}
460 	rc = 0;
461 out:
462 	/* Should be able to rely on deactivate_super called from
463 	 * get_sb_nodev */
464 	return rc;
465 }
466 
467 /**
468  * ecryptfs_read_super
469  * @sb: The ecryptfs super block
470  * @dev_name: The path to mount over
471  *
472  * Read the super block of the lower filesystem, and use
473  * ecryptfs_interpose to create our initial inode and super block
474  * struct.
475  */
476 static int ecryptfs_read_super(struct super_block *sb, const char *dev_name)
477 {
478 	int rc;
479 	struct nameidata nd;
480 	struct dentry *lower_root;
481 	struct vfsmount *lower_mnt;
482 
483 	memset(&nd, 0, sizeof(struct nameidata));
484 	rc = path_lookup(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &nd);
485 	if (rc) {
486 		ecryptfs_printk(KERN_WARNING, "path_lookup() failed\n");
487 		goto out;
488 	}
489 	lower_root = nd.path.dentry;
490 	lower_mnt = nd.path.mnt;
491 	ecryptfs_set_superblock_lower(sb, lower_root->d_sb);
492 	sb->s_maxbytes = lower_root->d_sb->s_maxbytes;
493 	sb->s_blocksize = lower_root->d_sb->s_blocksize;
494 	ecryptfs_set_dentry_lower(sb->s_root, lower_root);
495 	ecryptfs_set_dentry_lower_mnt(sb->s_root, lower_mnt);
496 	rc = ecryptfs_interpose(lower_root, sb->s_root, sb, 0);
497 	if (rc)
498 		goto out_free;
499 	rc = 0;
500 	goto out;
501 out_free:
502 	path_put(&nd.path);
503 out:
504 	return rc;
505 }
506 
507 /**
508  * ecryptfs_get_sb
509  * @fs_type
510  * @flags
511  * @dev_name: The path to mount over
512  * @raw_data: The options passed into the kernel
513  *
514  * The whole ecryptfs_get_sb process is broken into 4 functions:
515  * ecryptfs_parse_options(): handle options passed to ecryptfs, if any
516  * ecryptfs_fill_super(): used by get_sb_nodev, fills out the super_block
517  *                        with as much information as it can before needing
518  *                        the lower filesystem.
519  * ecryptfs_read_super(): this accesses the lower filesystem and uses
520  *                        ecryptfs_interpolate to perform most of the linking
521  * ecryptfs_interpolate(): links the lower filesystem into ecryptfs
522  */
523 static int ecryptfs_get_sb(struct file_system_type *fs_type, int flags,
524 			const char *dev_name, void *raw_data,
525 			struct vfsmount *mnt)
526 {
527 	int rc;
528 	struct super_block *sb;
529 
530 	rc = get_sb_nodev(fs_type, flags, raw_data, ecryptfs_fill_super, mnt);
531 	if (rc < 0) {
532 		printk(KERN_ERR "Getting sb failed; rc = [%d]\n", rc);
533 		goto out;
534 	}
535 	sb = mnt->mnt_sb;
536 	rc = ecryptfs_parse_options(sb, raw_data);
537 	if (rc) {
538 		printk(KERN_ERR "Error parsing options; rc = [%d]\n", rc);
539 		goto out_abort;
540 	}
541 	rc = ecryptfs_read_super(sb, dev_name);
542 	if (rc) {
543 		printk(KERN_ERR "Reading sb failed; rc = [%d]\n", rc);
544 		goto out_abort;
545 	}
546 	goto out;
547 out_abort:
548 	dput(sb->s_root);
549 	up_write(&sb->s_umount);
550 	deactivate_super(sb);
551 out:
552 	return rc;
553 }
554 
555 /**
556  * ecryptfs_kill_block_super
557  * @sb: The ecryptfs super block
558  *
559  * Used to bring the superblock down and free the private data.
560  * Private data is free'd in ecryptfs_put_super()
561  */
562 static void ecryptfs_kill_block_super(struct super_block *sb)
563 {
564 	generic_shutdown_super(sb);
565 }
566 
567 static struct file_system_type ecryptfs_fs_type = {
568 	.owner = THIS_MODULE,
569 	.name = "ecryptfs",
570 	.get_sb = ecryptfs_get_sb,
571 	.kill_sb = ecryptfs_kill_block_super,
572 	.fs_flags = 0
573 };
574 
575 /**
576  * inode_info_init_once
577  *
578  * Initializes the ecryptfs_inode_info_cache when it is created
579  */
580 static void
581 inode_info_init_once(struct kmem_cache *cachep, void *vptr)
582 {
583 	struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr;
584 
585 	inode_init_once(&ei->vfs_inode);
586 }
587 
588 static struct ecryptfs_cache_info {
589 	struct kmem_cache **cache;
590 	const char *name;
591 	size_t size;
592 	void (*ctor)(struct kmem_cache *cache, void *obj);
593 } ecryptfs_cache_infos[] = {
594 	{
595 		.cache = &ecryptfs_auth_tok_list_item_cache,
596 		.name = "ecryptfs_auth_tok_list_item",
597 		.size = sizeof(struct ecryptfs_auth_tok_list_item),
598 	},
599 	{
600 		.cache = &ecryptfs_file_info_cache,
601 		.name = "ecryptfs_file_cache",
602 		.size = sizeof(struct ecryptfs_file_info),
603 	},
604 	{
605 		.cache = &ecryptfs_dentry_info_cache,
606 		.name = "ecryptfs_dentry_info_cache",
607 		.size = sizeof(struct ecryptfs_dentry_info),
608 	},
609 	{
610 		.cache = &ecryptfs_inode_info_cache,
611 		.name = "ecryptfs_inode_cache",
612 		.size = sizeof(struct ecryptfs_inode_info),
613 		.ctor = inode_info_init_once,
614 	},
615 	{
616 		.cache = &ecryptfs_sb_info_cache,
617 		.name = "ecryptfs_sb_cache",
618 		.size = sizeof(struct ecryptfs_sb_info),
619 	},
620 	{
621 		.cache = &ecryptfs_header_cache_1,
622 		.name = "ecryptfs_headers_1",
623 		.size = PAGE_CACHE_SIZE,
624 	},
625 	{
626 		.cache = &ecryptfs_header_cache_2,
627 		.name = "ecryptfs_headers_2",
628 		.size = PAGE_CACHE_SIZE,
629 	},
630 	{
631 		.cache = &ecryptfs_xattr_cache,
632 		.name = "ecryptfs_xattr_cache",
633 		.size = PAGE_CACHE_SIZE,
634 	},
635 	{
636 		.cache = &ecryptfs_key_record_cache,
637 		.name = "ecryptfs_key_record_cache",
638 		.size = sizeof(struct ecryptfs_key_record),
639 	},
640 	{
641 		.cache = &ecryptfs_key_sig_cache,
642 		.name = "ecryptfs_key_sig_cache",
643 		.size = sizeof(struct ecryptfs_key_sig),
644 	},
645 	{
646 		.cache = &ecryptfs_global_auth_tok_cache,
647 		.name = "ecryptfs_global_auth_tok_cache",
648 		.size = sizeof(struct ecryptfs_global_auth_tok),
649 	},
650 	{
651 		.cache = &ecryptfs_key_tfm_cache,
652 		.name = "ecryptfs_key_tfm_cache",
653 		.size = sizeof(struct ecryptfs_key_tfm),
654 	},
655 	{
656 		.cache = &ecryptfs_open_req_cache,
657 		.name = "ecryptfs_open_req_cache",
658 		.size = sizeof(struct ecryptfs_open_req),
659 	},
660 };
661 
662 static void ecryptfs_free_kmem_caches(void)
663 {
664 	int i;
665 
666 	for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
667 		struct ecryptfs_cache_info *info;
668 
669 		info = &ecryptfs_cache_infos[i];
670 		if (*(info->cache))
671 			kmem_cache_destroy(*(info->cache));
672 	}
673 }
674 
675 /**
676  * ecryptfs_init_kmem_caches
677  *
678  * Returns zero on success; non-zero otherwise
679  */
680 static int ecryptfs_init_kmem_caches(void)
681 {
682 	int i;
683 
684 	for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
685 		struct ecryptfs_cache_info *info;
686 
687 		info = &ecryptfs_cache_infos[i];
688 		*(info->cache) = kmem_cache_create(info->name, info->size,
689 				0, SLAB_HWCACHE_ALIGN, info->ctor);
690 		if (!*(info->cache)) {
691 			ecryptfs_free_kmem_caches();
692 			ecryptfs_printk(KERN_WARNING, "%s: "
693 					"kmem_cache_create failed\n",
694 					info->name);
695 			return -ENOMEM;
696 		}
697 	}
698 	return 0;
699 }
700 
701 static struct kobject *ecryptfs_kobj;
702 
703 static ssize_t version_show(struct kobject *kobj,
704 			    struct kobj_attribute *attr, char *buff)
705 {
706 	return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK);
707 }
708 
709 static struct kobj_attribute version_attr = __ATTR_RO(version);
710 
711 static struct attribute *attributes[] = {
712 	&version_attr.attr,
713 	NULL,
714 };
715 
716 static struct attribute_group attr_group = {
717 	.attrs = attributes,
718 };
719 
720 static int do_sysfs_registration(void)
721 {
722 	int rc;
723 
724 	ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj);
725 	if (!ecryptfs_kobj) {
726 		printk(KERN_ERR "Unable to create ecryptfs kset\n");
727 		rc = -ENOMEM;
728 		goto out;
729 	}
730 	rc = sysfs_create_group(ecryptfs_kobj, &attr_group);
731 	if (rc) {
732 		printk(KERN_ERR
733 		       "Unable to create ecryptfs version attributes\n");
734 		kobject_put(ecryptfs_kobj);
735 	}
736 out:
737 	return rc;
738 }
739 
740 static void do_sysfs_unregistration(void)
741 {
742 	sysfs_remove_group(ecryptfs_kobj, &attr_group);
743 	kobject_put(ecryptfs_kobj);
744 }
745 
746 static int __init ecryptfs_init(void)
747 {
748 	int rc;
749 
750 	if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_CACHE_SIZE) {
751 		rc = -EINVAL;
752 		ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is "
753 				"larger than the host's page size, and so "
754 				"eCryptfs cannot run on this system. The "
755 				"default eCryptfs extent size is [%d] bytes; "
756 				"the page size is [%d] bytes.\n",
757 				ECRYPTFS_DEFAULT_EXTENT_SIZE, PAGE_CACHE_SIZE);
758 		goto out;
759 	}
760 	rc = ecryptfs_init_kmem_caches();
761 	if (rc) {
762 		printk(KERN_ERR
763 		       "Failed to allocate one or more kmem_cache objects\n");
764 		goto out;
765 	}
766 	rc = register_filesystem(&ecryptfs_fs_type);
767 	if (rc) {
768 		printk(KERN_ERR "Failed to register filesystem\n");
769 		goto out_free_kmem_caches;
770 	}
771 	rc = do_sysfs_registration();
772 	if (rc) {
773 		printk(KERN_ERR "sysfs registration failed\n");
774 		goto out_unregister_filesystem;
775 	}
776 	rc = ecryptfs_init_kthread();
777 	if (rc) {
778 		printk(KERN_ERR "%s: kthread initialization failed; "
779 		       "rc = [%d]\n", __func__, rc);
780 		goto out_do_sysfs_unregistration;
781 	}
782 	rc = ecryptfs_init_messaging(ecryptfs_transport);
783 	if (rc) {
784 		printk(KERN_ERR "Failure occured while attempting to "
785 				"initialize the eCryptfs netlink socket\n");
786 		goto out_destroy_kthread;
787 	}
788 	rc = ecryptfs_init_crypto();
789 	if (rc) {
790 		printk(KERN_ERR "Failure whilst attempting to init crypto; "
791 		       "rc = [%d]\n", rc);
792 		goto out_release_messaging;
793 	}
794 	if (ecryptfs_verbosity > 0)
795 		printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values "
796 			"will be written to the syslog!\n", ecryptfs_verbosity);
797 
798 	goto out;
799 out_release_messaging:
800 	ecryptfs_release_messaging(ecryptfs_transport);
801 out_destroy_kthread:
802 	ecryptfs_destroy_kthread();
803 out_do_sysfs_unregistration:
804 	do_sysfs_unregistration();
805 out_unregister_filesystem:
806 	unregister_filesystem(&ecryptfs_fs_type);
807 out_free_kmem_caches:
808 	ecryptfs_free_kmem_caches();
809 out:
810 	return rc;
811 }
812 
813 static void __exit ecryptfs_exit(void)
814 {
815 	int rc;
816 
817 	rc = ecryptfs_destroy_crypto();
818 	if (rc)
819 		printk(KERN_ERR "Failure whilst attempting to destroy crypto; "
820 		       "rc = [%d]\n", rc);
821 	ecryptfs_release_messaging(ecryptfs_transport);
822 	ecryptfs_destroy_kthread();
823 	do_sysfs_unregistration();
824 	unregister_filesystem(&ecryptfs_fs_type);
825 	ecryptfs_free_kmem_caches();
826 }
827 
828 MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>");
829 MODULE_DESCRIPTION("eCryptfs");
830 
831 MODULE_LICENSE("GPL");
832 
833 module_init(ecryptfs_init)
834 module_exit(ecryptfs_exit)
835