Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ecryptfs...
[~shefty/rdma-dev.git] / fs / ecryptfs / main.c
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/mount.h>
34 #include <linux/pagemap.h>
35 #include <linux/key.h>
36 #include <linux/parser.h>
37 #include <linux/fs_stack.h>
38 #include <linux/slab.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 message buffer elements
53  */
54 unsigned int ecryptfs_message_buf_len = ECRYPTFS_DEFAULT_MSG_CTX_ELEMS;
55
56 module_param(ecryptfs_message_buf_len, uint, 0);
57 MODULE_PARM_DESC(ecryptfs_message_buf_len,
58                  "Number of message buffer elements");
59
60 /**
61  * Module parameter that defines the maximum guaranteed amount of time to wait
62  * for a response from ecryptfsd.  The actual sleep time will be, more than
63  * likely, a small amount greater than this specified value, but only less if
64  * the message successfully arrives.
65  */
66 signed long ecryptfs_message_wait_timeout = ECRYPTFS_MAX_MSG_CTX_TTL / HZ;
67
68 module_param(ecryptfs_message_wait_timeout, long, 0);
69 MODULE_PARM_DESC(ecryptfs_message_wait_timeout,
70                  "Maximum number of seconds that an operation will "
71                  "sleep while waiting for a message response from "
72                  "userspace");
73
74 /**
75  * Module parameter that is an estimate of the maximum number of users
76  * that will be concurrently using eCryptfs. Set this to the right
77  * value to balance performance and memory use.
78  */
79 unsigned int ecryptfs_number_of_users = ECRYPTFS_DEFAULT_NUM_USERS;
80
81 module_param(ecryptfs_number_of_users, uint, 0);
82 MODULE_PARM_DESC(ecryptfs_number_of_users, "An estimate of the number of "
83                  "concurrent users of eCryptfs");
84
85 void __ecryptfs_printk(const char *fmt, ...)
86 {
87         va_list args;
88         va_start(args, fmt);
89         if (fmt[1] == '7') { /* KERN_DEBUG */
90                 if (ecryptfs_verbosity >= 1)
91                         vprintk(fmt, args);
92         } else
93                 vprintk(fmt, args);
94         va_end(args);
95 }
96
97 /**
98  * ecryptfs_init_persistent_file
99  * @ecryptfs_dentry: Fully initialized eCryptfs dentry object, with
100  *                   the lower dentry and the lower mount set
101  *
102  * eCryptfs only ever keeps a single open file for every lower
103  * inode. All I/O operations to the lower inode occur through that
104  * file. When the first eCryptfs dentry that interposes with the first
105  * lower dentry for that inode is created, this function creates the
106  * persistent file struct and associates it with the eCryptfs
107  * inode. When the eCryptfs inode is destroyed, the file is closed.
108  *
109  * The persistent file will be opened with read/write permissions, if
110  * possible. Otherwise, it is opened read-only.
111  *
112  * This function does nothing if a lower persistent file is already
113  * associated with the eCryptfs inode.
114  *
115  * Returns zero on success; non-zero otherwise
116  */
117 int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry)
118 {
119         const struct cred *cred = current_cred();
120         struct ecryptfs_inode_info *inode_info =
121                 ecryptfs_inode_to_private(ecryptfs_dentry->d_inode);
122         int rc = 0;
123
124         mutex_lock(&inode_info->lower_file_mutex);
125         if (!inode_info->lower_file) {
126                 struct dentry *lower_dentry;
127                 struct vfsmount *lower_mnt =
128                         ecryptfs_dentry_to_lower_mnt(ecryptfs_dentry);
129
130                 lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
131                 rc = ecryptfs_privileged_open(&inode_info->lower_file,
132                                               lower_dentry, lower_mnt, cred);
133                 if (rc) {
134                         printk(KERN_ERR "Error opening lower persistent file "
135                                "for lower_dentry [0x%p] and lower_mnt [0x%p]; "
136                                "rc = [%d]\n", lower_dentry, lower_mnt, rc);
137                         inode_info->lower_file = NULL;
138                 }
139         }
140         mutex_unlock(&inode_info->lower_file_mutex);
141         return rc;
142 }
143
144 /**
145  * ecryptfs_interpose
146  * @lower_dentry: Existing dentry in the lower filesystem
147  * @dentry: ecryptfs' dentry
148  * @sb: ecryptfs's super_block
149  * @flags: flags to govern behavior of interpose procedure
150  *
151  * Interposes upper and lower dentries.
152  *
153  * Returns zero on success; non-zero otherwise
154  */
155 int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry,
156                        struct super_block *sb, u32 flags)
157 {
158         struct inode *lower_inode;
159         struct inode *inode;
160         int rc = 0;
161
162         lower_inode = lower_dentry->d_inode;
163         if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb)) {
164                 rc = -EXDEV;
165                 goto out;
166         }
167         if (!igrab(lower_inode)) {
168                 rc = -ESTALE;
169                 goto out;
170         }
171         inode = iget5_locked(sb, (unsigned long)lower_inode,
172                              ecryptfs_inode_test, ecryptfs_inode_set,
173                              lower_inode);
174         if (!inode) {
175                 rc = -EACCES;
176                 iput(lower_inode);
177                 goto out;
178         }
179         if (inode->i_state & I_NEW)
180                 unlock_new_inode(inode);
181         else
182                 iput(lower_inode);
183         if (S_ISLNK(lower_inode->i_mode))
184                 inode->i_op = &ecryptfs_symlink_iops;
185         else if (S_ISDIR(lower_inode->i_mode))
186                 inode->i_op = &ecryptfs_dir_iops;
187         if (S_ISDIR(lower_inode->i_mode))
188                 inode->i_fop = &ecryptfs_dir_fops;
189         if (special_file(lower_inode->i_mode))
190                 init_special_inode(inode, lower_inode->i_mode,
191                                    lower_inode->i_rdev);
192         dentry->d_op = &ecryptfs_dops;
193         fsstack_copy_attr_all(inode, lower_inode);
194         /* This size will be overwritten for real files w/ headers and
195          * other metadata */
196         fsstack_copy_inode_size(inode, lower_inode);
197         if (flags & ECRYPTFS_INTERPOSE_FLAG_D_ADD)
198                 d_add(dentry, inode);
199         else
200                 d_instantiate(dentry, inode);
201 out:
202         return rc;
203 }
204
205 enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig,
206        ecryptfs_opt_cipher, ecryptfs_opt_ecryptfs_cipher,
207        ecryptfs_opt_ecryptfs_key_bytes,
208        ecryptfs_opt_passthrough, ecryptfs_opt_xattr_metadata,
209        ecryptfs_opt_encrypted_view, ecryptfs_opt_fnek_sig,
210        ecryptfs_opt_fn_cipher, ecryptfs_opt_fn_cipher_key_bytes,
211        ecryptfs_opt_unlink_sigs, ecryptfs_opt_mount_auth_tok_only,
212        ecryptfs_opt_err };
213
214 static const 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_fnek_sig, "ecryptfs_fnek_sig=%s"},
224         {ecryptfs_opt_fn_cipher, "ecryptfs_fn_cipher=%s"},
225         {ecryptfs_opt_fn_cipher_key_bytes, "ecryptfs_fn_key_bytes=%u"},
226         {ecryptfs_opt_unlink_sigs, "ecryptfs_unlink_sigs"},
227         {ecryptfs_opt_mount_auth_tok_only, "ecryptfs_mount_auth_tok_only"},
228         {ecryptfs_opt_err, NULL}
229 };
230
231 static int ecryptfs_init_global_auth_toks(
232         struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
233 {
234         struct ecryptfs_global_auth_tok *global_auth_tok;
235         int rc = 0;
236
237         list_for_each_entry(global_auth_tok,
238                             &mount_crypt_stat->global_auth_tok_list,
239                             mount_crypt_stat_list) {
240                 rc = ecryptfs_keyring_auth_tok_for_sig(
241                         &global_auth_tok->global_auth_tok_key,
242                         &global_auth_tok->global_auth_tok,
243                         global_auth_tok->sig);
244                 if (rc) {
245                         printk(KERN_ERR "Could not find valid key in user "
246                                "session keyring for sig specified in mount "
247                                "option: [%s]\n", global_auth_tok->sig);
248                         global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID;
249                         goto out;
250                 } else
251                         global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID;
252         }
253 out:
254         return rc;
255 }
256
257 static void ecryptfs_init_mount_crypt_stat(
258         struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
259 {
260         memset((void *)mount_crypt_stat, 0,
261                sizeof(struct ecryptfs_mount_crypt_stat));
262         INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list);
263         mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex);
264         mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED;
265 }
266
267 /**
268  * ecryptfs_parse_options
269  * @sb: The ecryptfs super block
270  * @options: The options pased to the kernel
271  *
272  * Parse mount options:
273  * debug=N         - ecryptfs_verbosity level for debug output
274  * sig=XXX         - description(signature) of the key to use
275  *
276  * Returns the dentry object of the lower-level (lower/interposed)
277  * directory; We want to mount our stackable file system on top of
278  * that lower directory.
279  *
280  * The signature of the key to use must be the description of a key
281  * already in the keyring. Mounting will fail if the key can not be
282  * found.
283  *
284  * Returns zero on success; non-zero on error
285  */
286 static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options)
287 {
288         char *p;
289         int rc = 0;
290         int sig_set = 0;
291         int cipher_name_set = 0;
292         int fn_cipher_name_set = 0;
293         int cipher_key_bytes;
294         int cipher_key_bytes_set = 0;
295         int fn_cipher_key_bytes;
296         int fn_cipher_key_bytes_set = 0;
297         struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
298                 &sbi->mount_crypt_stat;
299         substring_t args[MAX_OPT_ARGS];
300         int token;
301         char *sig_src;
302         char *cipher_name_dst;
303         char *cipher_name_src;
304         char *fn_cipher_name_dst;
305         char *fn_cipher_name_src;
306         char *fnek_dst;
307         char *fnek_src;
308         char *cipher_key_bytes_src;
309         char *fn_cipher_key_bytes_src;
310
311         if (!options) {
312                 rc = -EINVAL;
313                 goto out;
314         }
315         ecryptfs_init_mount_crypt_stat(mount_crypt_stat);
316         while ((p = strsep(&options, ",")) != NULL) {
317                 if (!*p)
318                         continue;
319                 token = match_token(p, tokens, args);
320                 switch (token) {
321                 case ecryptfs_opt_sig:
322                 case ecryptfs_opt_ecryptfs_sig:
323                         sig_src = args[0].from;
324                         rc = ecryptfs_add_global_auth_tok(mount_crypt_stat,
325                                                           sig_src, 0);
326                         if (rc) {
327                                 printk(KERN_ERR "Error attempting to register "
328                                        "global sig; rc = [%d]\n", rc);
329                                 goto out;
330                         }
331                         sig_set = 1;
332                         break;
333                 case ecryptfs_opt_cipher:
334                 case ecryptfs_opt_ecryptfs_cipher:
335                         cipher_name_src = args[0].from;
336                         cipher_name_dst =
337                                 mount_crypt_stat->
338                                 global_default_cipher_name;
339                         strncpy(cipher_name_dst, cipher_name_src,
340                                 ECRYPTFS_MAX_CIPHER_NAME_SIZE);
341                         cipher_name_dst[ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0';
342                         cipher_name_set = 1;
343                         break;
344                 case ecryptfs_opt_ecryptfs_key_bytes:
345                         cipher_key_bytes_src = args[0].from;
346                         cipher_key_bytes =
347                                 (int)simple_strtol(cipher_key_bytes_src,
348                                                    &cipher_key_bytes_src, 0);
349                         mount_crypt_stat->global_default_cipher_key_size =
350                                 cipher_key_bytes;
351                         cipher_key_bytes_set = 1;
352                         break;
353                 case ecryptfs_opt_passthrough:
354                         mount_crypt_stat->flags |=
355                                 ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED;
356                         break;
357                 case ecryptfs_opt_xattr_metadata:
358                         mount_crypt_stat->flags |=
359                                 ECRYPTFS_XATTR_METADATA_ENABLED;
360                         break;
361                 case ecryptfs_opt_encrypted_view:
362                         mount_crypt_stat->flags |=
363                                 ECRYPTFS_XATTR_METADATA_ENABLED;
364                         mount_crypt_stat->flags |=
365                                 ECRYPTFS_ENCRYPTED_VIEW_ENABLED;
366                         break;
367                 case ecryptfs_opt_fnek_sig:
368                         fnek_src = args[0].from;
369                         fnek_dst =
370                                 mount_crypt_stat->global_default_fnek_sig;
371                         strncpy(fnek_dst, fnek_src, ECRYPTFS_SIG_SIZE_HEX);
372                         mount_crypt_stat->global_default_fnek_sig[
373                                 ECRYPTFS_SIG_SIZE_HEX] = '\0';
374                         rc = ecryptfs_add_global_auth_tok(
375                                 mount_crypt_stat,
376                                 mount_crypt_stat->global_default_fnek_sig,
377                                 ECRYPTFS_AUTH_TOK_FNEK);
378                         if (rc) {
379                                 printk(KERN_ERR "Error attempting to register "
380                                        "global fnek sig [%s]; rc = [%d]\n",
381                                        mount_crypt_stat->global_default_fnek_sig,
382                                        rc);
383                                 goto out;
384                         }
385                         mount_crypt_stat->flags |=
386                                 (ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
387                                  | ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK);
388                         break;
389                 case ecryptfs_opt_fn_cipher:
390                         fn_cipher_name_src = args[0].from;
391                         fn_cipher_name_dst =
392                                 mount_crypt_stat->global_default_fn_cipher_name;
393                         strncpy(fn_cipher_name_dst, fn_cipher_name_src,
394                                 ECRYPTFS_MAX_CIPHER_NAME_SIZE);
395                         mount_crypt_stat->global_default_fn_cipher_name[
396                                 ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0';
397                         fn_cipher_name_set = 1;
398                         break;
399                 case ecryptfs_opt_fn_cipher_key_bytes:
400                         fn_cipher_key_bytes_src = args[0].from;
401                         fn_cipher_key_bytes =
402                                 (int)simple_strtol(fn_cipher_key_bytes_src,
403                                                    &fn_cipher_key_bytes_src, 0);
404                         mount_crypt_stat->global_default_fn_cipher_key_bytes =
405                                 fn_cipher_key_bytes;
406                         fn_cipher_key_bytes_set = 1;
407                         break;
408                 case ecryptfs_opt_unlink_sigs:
409                         mount_crypt_stat->flags |= ECRYPTFS_UNLINK_SIGS;
410                         break;
411                 case ecryptfs_opt_mount_auth_tok_only:
412                         mount_crypt_stat->flags |=
413                                 ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY;
414                         break;
415                 case ecryptfs_opt_err:
416                 default:
417                         printk(KERN_WARNING
418                                "%s: eCryptfs: unrecognized option [%s]\n",
419                                __func__, p);
420                 }
421         }
422         if (!sig_set) {
423                 rc = -EINVAL;
424                 ecryptfs_printk(KERN_ERR, "You must supply at least one valid "
425                                 "auth tok signature as a mount "
426                                 "parameter; see the eCryptfs README\n");
427                 goto out;
428         }
429         if (!cipher_name_set) {
430                 int cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER);
431
432                 BUG_ON(cipher_name_len >= ECRYPTFS_MAX_CIPHER_NAME_SIZE);
433                 strcpy(mount_crypt_stat->global_default_cipher_name,
434                        ECRYPTFS_DEFAULT_CIPHER);
435         }
436         if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
437             && !fn_cipher_name_set)
438                 strcpy(mount_crypt_stat->global_default_fn_cipher_name,
439                        mount_crypt_stat->global_default_cipher_name);
440         if (!cipher_key_bytes_set)
441                 mount_crypt_stat->global_default_cipher_key_size = 0;
442         if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
443             && !fn_cipher_key_bytes_set)
444                 mount_crypt_stat->global_default_fn_cipher_key_bytes =
445                         mount_crypt_stat->global_default_cipher_key_size;
446         mutex_lock(&key_tfm_list_mutex);
447         if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name,
448                                  NULL)) {
449                 rc = ecryptfs_add_new_key_tfm(
450                         NULL, mount_crypt_stat->global_default_cipher_name,
451                         mount_crypt_stat->global_default_cipher_key_size);
452                 if (rc) {
453                         printk(KERN_ERR "Error attempting to initialize "
454                                "cipher with name = [%s] and key size = [%td]; "
455                                "rc = [%d]\n",
456                                mount_crypt_stat->global_default_cipher_name,
457                                mount_crypt_stat->global_default_cipher_key_size,
458                                rc);
459                         rc = -EINVAL;
460                         mutex_unlock(&key_tfm_list_mutex);
461                         goto out;
462                 }
463         }
464         if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
465             && !ecryptfs_tfm_exists(
466                     mount_crypt_stat->global_default_fn_cipher_name, NULL)) {
467                 rc = ecryptfs_add_new_key_tfm(
468                         NULL, mount_crypt_stat->global_default_fn_cipher_name,
469                         mount_crypt_stat->global_default_fn_cipher_key_bytes);
470                 if (rc) {
471                         printk(KERN_ERR "Error attempting to initialize "
472                                "cipher with name = [%s] and key size = [%td]; "
473                                "rc = [%d]\n",
474                                mount_crypt_stat->global_default_fn_cipher_name,
475                                mount_crypt_stat->global_default_fn_cipher_key_bytes,
476                                rc);
477                         rc = -EINVAL;
478                         mutex_unlock(&key_tfm_list_mutex);
479                         goto out;
480                 }
481         }
482         mutex_unlock(&key_tfm_list_mutex);
483         rc = ecryptfs_init_global_auth_toks(mount_crypt_stat);
484         if (rc)
485                 printk(KERN_WARNING "One or more global auth toks could not "
486                        "properly register; rc = [%d]\n", rc);
487 out:
488         return rc;
489 }
490
491 struct kmem_cache *ecryptfs_sb_info_cache;
492 static struct file_system_type ecryptfs_fs_type;
493
494 /**
495  * ecryptfs_read_super
496  * @sb: The ecryptfs super block
497  * @dev_name: The path to mount over
498  *
499  * Read the super block of the lower filesystem, and use
500  * ecryptfs_interpose to create our initial inode and super block
501  * struct.
502  */
503 static int ecryptfs_read_super(struct super_block *sb, const char *dev_name)
504 {
505         struct path path;
506         int rc;
507
508         rc = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path);
509         if (rc) {
510                 ecryptfs_printk(KERN_WARNING, "path_lookup() failed\n");
511                 goto out;
512         }
513         if (path.dentry->d_sb->s_type == &ecryptfs_fs_type) {
514                 rc = -EINVAL;
515                 printk(KERN_ERR "Mount on filesystem of type "
516                         "eCryptfs explicitly disallowed due to "
517                         "known incompatibilities\n");
518                 goto out_free;
519         }
520         ecryptfs_set_superblock_lower(sb, path.dentry->d_sb);
521         sb->s_maxbytes = path.dentry->d_sb->s_maxbytes;
522         sb->s_blocksize = path.dentry->d_sb->s_blocksize;
523         ecryptfs_set_dentry_lower(sb->s_root, path.dentry);
524         ecryptfs_set_dentry_lower_mnt(sb->s_root, path.mnt);
525         rc = ecryptfs_interpose(path.dentry, sb->s_root, sb, 0);
526         if (rc)
527                 goto out_free;
528         rc = 0;
529         goto out;
530 out_free:
531         path_put(&path);
532 out:
533         return rc;
534 }
535
536 /**
537  * ecryptfs_get_sb
538  * @fs_type
539  * @flags
540  * @dev_name: The path to mount over
541  * @raw_data: The options passed into the kernel
542  *
543  * The whole ecryptfs_get_sb process is broken into 3 functions:
544  * ecryptfs_parse_options(): handle options passed to ecryptfs, if any
545  * ecryptfs_read_super(): this accesses the lower filesystem and uses
546  *                        ecryptfs_interpose to perform most of the linking
547  * ecryptfs_interpose(): links the lower filesystem into ecryptfs (inode.c)
548  */
549 static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags,
550                         const char *dev_name, void *raw_data)
551 {
552         struct super_block *s;
553         struct ecryptfs_sb_info *sbi;
554         struct ecryptfs_dentry_info *root_info;
555         const char *err = "Getting sb failed";
556         int rc;
557
558         sbi = kmem_cache_zalloc(ecryptfs_sb_info_cache, GFP_KERNEL);
559         if (!sbi) {
560                 rc = -ENOMEM;
561                 goto out;
562         }
563
564         rc = ecryptfs_parse_options(sbi, raw_data);
565         if (rc) {
566                 err = "Error parsing options";
567                 goto out;
568         }
569
570         s = sget(fs_type, NULL, set_anon_super, NULL);
571         if (IS_ERR(s)) {
572                 rc = PTR_ERR(s);
573                 goto out;
574         }
575
576         s->s_flags = flags;
577         rc = bdi_setup_and_register(&sbi->bdi, "ecryptfs", BDI_CAP_MAP_COPY);
578         if (rc) {
579                 deactivate_locked_super(s);
580                 goto out;
581         }
582
583         ecryptfs_set_superblock_private(s, sbi);
584         s->s_bdi = &sbi->bdi;
585
586         /* ->kill_sb() will take care of sbi after that point */
587         sbi = NULL;
588         s->s_op = &ecryptfs_sops;
589
590         rc = -ENOMEM;
591         s->s_root = d_alloc(NULL, &(const struct qstr) {
592                              .hash = 0,.name = "/",.len = 1});
593         if (!s->s_root) {
594                 deactivate_locked_super(s);
595                 goto out;
596         }
597         s->s_root->d_op = &ecryptfs_dops;
598         s->s_root->d_sb = s;
599         s->s_root->d_parent = s->s_root;
600
601         root_info = kmem_cache_zalloc(ecryptfs_dentry_info_cache, GFP_KERNEL);
602         if (!root_info) {
603                 deactivate_locked_super(s);
604                 goto out;
605         }
606         /* ->kill_sb() will take care of root_info */
607         ecryptfs_set_dentry_private(s->s_root, root_info);
608         s->s_flags |= MS_ACTIVE;
609         rc = ecryptfs_read_super(s, dev_name);
610         if (rc) {
611                 deactivate_locked_super(s);
612                 err = "Reading sb failed";
613                 goto out;
614         }
615         return dget(s->s_root);
616
617 out:
618         if (sbi) {
619                 ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat);
620                 kmem_cache_free(ecryptfs_sb_info_cache, sbi);
621         }
622         printk(KERN_ERR "%s; rc = [%d]\n", err, rc);
623         return ERR_PTR(rc);
624 }
625
626 /**
627  * ecryptfs_kill_block_super
628  * @sb: The ecryptfs super block
629  *
630  * Used to bring the superblock down and free the private data.
631  */
632 static void ecryptfs_kill_block_super(struct super_block *sb)
633 {
634         struct ecryptfs_sb_info *sb_info = ecryptfs_superblock_to_private(sb);
635         kill_anon_super(sb);
636         if (!sb_info)
637                 return;
638         ecryptfs_destroy_mount_crypt_stat(&sb_info->mount_crypt_stat);
639         bdi_destroy(&sb_info->bdi);
640         kmem_cache_free(ecryptfs_sb_info_cache, sb_info);
641 }
642
643 static struct file_system_type ecryptfs_fs_type = {
644         .owner = THIS_MODULE,
645         .name = "ecryptfs",
646         .mount = ecryptfs_mount,
647         .kill_sb = ecryptfs_kill_block_super,
648         .fs_flags = 0
649 };
650
651 /**
652  * inode_info_init_once
653  *
654  * Initializes the ecryptfs_inode_info_cache when it is created
655  */
656 static void
657 inode_info_init_once(void *vptr)
658 {
659         struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr;
660
661         inode_init_once(&ei->vfs_inode);
662 }
663
664 static struct ecryptfs_cache_info {
665         struct kmem_cache **cache;
666         const char *name;
667         size_t size;
668         void (*ctor)(void *obj);
669 } ecryptfs_cache_infos[] = {
670         {
671                 .cache = &ecryptfs_auth_tok_list_item_cache,
672                 .name = "ecryptfs_auth_tok_list_item",
673                 .size = sizeof(struct ecryptfs_auth_tok_list_item),
674         },
675         {
676                 .cache = &ecryptfs_file_info_cache,
677                 .name = "ecryptfs_file_cache",
678                 .size = sizeof(struct ecryptfs_file_info),
679         },
680         {
681                 .cache = &ecryptfs_dentry_info_cache,
682                 .name = "ecryptfs_dentry_info_cache",
683                 .size = sizeof(struct ecryptfs_dentry_info),
684         },
685         {
686                 .cache = &ecryptfs_inode_info_cache,
687                 .name = "ecryptfs_inode_cache",
688                 .size = sizeof(struct ecryptfs_inode_info),
689                 .ctor = inode_info_init_once,
690         },
691         {
692                 .cache = &ecryptfs_sb_info_cache,
693                 .name = "ecryptfs_sb_cache",
694                 .size = sizeof(struct ecryptfs_sb_info),
695         },
696         {
697                 .cache = &ecryptfs_header_cache_1,
698                 .name = "ecryptfs_headers_1",
699                 .size = PAGE_CACHE_SIZE,
700         },
701         {
702                 .cache = &ecryptfs_header_cache_2,
703                 .name = "ecryptfs_headers_2",
704                 .size = PAGE_CACHE_SIZE,
705         },
706         {
707                 .cache = &ecryptfs_xattr_cache,
708                 .name = "ecryptfs_xattr_cache",
709                 .size = PAGE_CACHE_SIZE,
710         },
711         {
712                 .cache = &ecryptfs_key_record_cache,
713                 .name = "ecryptfs_key_record_cache",
714                 .size = sizeof(struct ecryptfs_key_record),
715         },
716         {
717                 .cache = &ecryptfs_key_sig_cache,
718                 .name = "ecryptfs_key_sig_cache",
719                 .size = sizeof(struct ecryptfs_key_sig),
720         },
721         {
722                 .cache = &ecryptfs_global_auth_tok_cache,
723                 .name = "ecryptfs_global_auth_tok_cache",
724                 .size = sizeof(struct ecryptfs_global_auth_tok),
725         },
726         {
727                 .cache = &ecryptfs_key_tfm_cache,
728                 .name = "ecryptfs_key_tfm_cache",
729                 .size = sizeof(struct ecryptfs_key_tfm),
730         },
731         {
732                 .cache = &ecryptfs_open_req_cache,
733                 .name = "ecryptfs_open_req_cache",
734                 .size = sizeof(struct ecryptfs_open_req),
735         },
736 };
737
738 static void ecryptfs_free_kmem_caches(void)
739 {
740         int i;
741
742         for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
743                 struct ecryptfs_cache_info *info;
744
745                 info = &ecryptfs_cache_infos[i];
746                 if (*(info->cache))
747                         kmem_cache_destroy(*(info->cache));
748         }
749 }
750
751 /**
752  * ecryptfs_init_kmem_caches
753  *
754  * Returns zero on success; non-zero otherwise
755  */
756 static int ecryptfs_init_kmem_caches(void)
757 {
758         int i;
759
760         for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
761                 struct ecryptfs_cache_info *info;
762
763                 info = &ecryptfs_cache_infos[i];
764                 *(info->cache) = kmem_cache_create(info->name, info->size,
765                                 0, SLAB_HWCACHE_ALIGN, info->ctor);
766                 if (!*(info->cache)) {
767                         ecryptfs_free_kmem_caches();
768                         ecryptfs_printk(KERN_WARNING, "%s: "
769                                         "kmem_cache_create failed\n",
770                                         info->name);
771                         return -ENOMEM;
772                 }
773         }
774         return 0;
775 }
776
777 static struct kobject *ecryptfs_kobj;
778
779 static ssize_t version_show(struct kobject *kobj,
780                             struct kobj_attribute *attr, char *buff)
781 {
782         return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK);
783 }
784
785 static struct kobj_attribute version_attr = __ATTR_RO(version);
786
787 static struct attribute *attributes[] = {
788         &version_attr.attr,
789         NULL,
790 };
791
792 static struct attribute_group attr_group = {
793         .attrs = attributes,
794 };
795
796 static int do_sysfs_registration(void)
797 {
798         int rc;
799
800         ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj);
801         if (!ecryptfs_kobj) {
802                 printk(KERN_ERR "Unable to create ecryptfs kset\n");
803                 rc = -ENOMEM;
804                 goto out;
805         }
806         rc = sysfs_create_group(ecryptfs_kobj, &attr_group);
807         if (rc) {
808                 printk(KERN_ERR
809                        "Unable to create ecryptfs version attributes\n");
810                 kobject_put(ecryptfs_kobj);
811         }
812 out:
813         return rc;
814 }
815
816 static void do_sysfs_unregistration(void)
817 {
818         sysfs_remove_group(ecryptfs_kobj, &attr_group);
819         kobject_put(ecryptfs_kobj);
820 }
821
822 static int __init ecryptfs_init(void)
823 {
824         int rc;
825
826         if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_CACHE_SIZE) {
827                 rc = -EINVAL;
828                 ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is "
829                                 "larger than the host's page size, and so "
830                                 "eCryptfs cannot run on this system. The "
831                                 "default eCryptfs extent size is [%d] bytes; "
832                                 "the page size is [%d] bytes.\n",
833                                 ECRYPTFS_DEFAULT_EXTENT_SIZE, PAGE_CACHE_SIZE);
834                 goto out;
835         }
836         rc = ecryptfs_init_kmem_caches();
837         if (rc) {
838                 printk(KERN_ERR
839                        "Failed to allocate one or more kmem_cache objects\n");
840                 goto out;
841         }
842         rc = register_filesystem(&ecryptfs_fs_type);
843         if (rc) {
844                 printk(KERN_ERR "Failed to register filesystem\n");
845                 goto out_free_kmem_caches;
846         }
847         rc = do_sysfs_registration();
848         if (rc) {
849                 printk(KERN_ERR "sysfs registration failed\n");
850                 goto out_unregister_filesystem;
851         }
852         rc = ecryptfs_init_kthread();
853         if (rc) {
854                 printk(KERN_ERR "%s: kthread initialization failed; "
855                        "rc = [%d]\n", __func__, rc);
856                 goto out_do_sysfs_unregistration;
857         }
858         rc = ecryptfs_init_messaging();
859         if (rc) {
860                 printk(KERN_ERR "Failure occured while attempting to "
861                                 "initialize the communications channel to "
862                                 "ecryptfsd\n");
863                 goto out_destroy_kthread;
864         }
865         rc = ecryptfs_init_crypto();
866         if (rc) {
867                 printk(KERN_ERR "Failure whilst attempting to init crypto; "
868                        "rc = [%d]\n", rc);
869                 goto out_release_messaging;
870         }
871         if (ecryptfs_verbosity > 0)
872                 printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values "
873                         "will be written to the syslog!\n", ecryptfs_verbosity);
874
875         goto out;
876 out_release_messaging:
877         ecryptfs_release_messaging();
878 out_destroy_kthread:
879         ecryptfs_destroy_kthread();
880 out_do_sysfs_unregistration:
881         do_sysfs_unregistration();
882 out_unregister_filesystem:
883         unregister_filesystem(&ecryptfs_fs_type);
884 out_free_kmem_caches:
885         ecryptfs_free_kmem_caches();
886 out:
887         return rc;
888 }
889
890 static void __exit ecryptfs_exit(void)
891 {
892         int rc;
893
894         rc = ecryptfs_destroy_crypto();
895         if (rc)
896                 printk(KERN_ERR "Failure whilst attempting to destroy crypto; "
897                        "rc = [%d]\n", rc);
898         ecryptfs_release_messaging();
899         ecryptfs_destroy_kthread();
900         do_sysfs_unregistration();
901         unregister_filesystem(&ecryptfs_fs_type);
902         ecryptfs_free_kmem_caches();
903 }
904
905 MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>");
906 MODULE_DESCRIPTION("eCryptfs");
907
908 MODULE_LICENSE("GPL");
909
910 module_init(ecryptfs_init)
911 module_exit(ecryptfs_exit)