eCryptfs: Return error when lower file pointer is NULL
[linux-3.10.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 <linux/magic.h>
40 #include "ecryptfs_kernel.h"
41
42 /**
43  * Module parameter that defines the ecryptfs_verbosity level.
44  */
45 int ecryptfs_verbosity = 0;
46
47 module_param(ecryptfs_verbosity, int, 0);
48 MODULE_PARM_DESC(ecryptfs_verbosity,
49                  "Initial verbosity level (0 or 1; defaults to "
50                  "0, which is Quiet)");
51
52 /**
53  * Module parameter that defines the number of message buffer 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 from ecryptfsd.  The actual sleep time will be, more than
64  * likely, a small amount greater than this specified value, but only less if
65  * the 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 void __ecryptfs_printk(const char *fmt, ...)
87 {
88         va_list args;
89         va_start(args, fmt);
90         if (fmt[1] == '7') { /* KERN_DEBUG */
91                 if (ecryptfs_verbosity >= 1)
92                         vprintk(fmt, args);
93         } else
94                 vprintk(fmt, args);
95         va_end(args);
96 }
97
98 /**
99  * ecryptfs_init_lower_file
100  * @ecryptfs_dentry: Fully initialized eCryptfs dentry object, with
101  *                   the lower dentry and the lower mount set
102  *
103  * eCryptfs only ever keeps a single open file for every lower
104  * inode. All I/O operations to the lower inode occur through that
105  * file. When the first eCryptfs dentry that interposes with the first
106  * lower dentry for that inode is created, this function creates the
107  * lower file struct and associates it with the eCryptfs
108  * inode. When all eCryptfs files associated with the inode are released, the
109  * file is closed.
110  *
111  * The lower file will be opened with read/write permissions, if
112  * possible. Otherwise, it is opened read-only.
113  *
114  * This function does nothing if a lower file is already
115  * associated with the eCryptfs inode.
116  *
117  * Returns zero on success; non-zero otherwise
118  */
119 static int ecryptfs_init_lower_file(struct dentry *dentry,
120                                     struct file **lower_file)
121 {
122         const struct cred *cred = current_cred();
123         struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
124         struct vfsmount *lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry);
125         int rc;
126
127         rc = ecryptfs_privileged_open(lower_file, lower_dentry, lower_mnt,
128                                       cred);
129         if (rc) {
130                 printk(KERN_ERR "Error opening lower file "
131                        "for lower_dentry [0x%p] and lower_mnt [0x%p]; "
132                        "rc = [%d]\n", lower_dentry, lower_mnt, rc);
133                 (*lower_file) = NULL;
134         }
135         return rc;
136 }
137
138 int ecryptfs_get_lower_file(struct dentry *dentry, struct inode *inode)
139 {
140         struct ecryptfs_inode_info *inode_info;
141         int count, rc = 0;
142
143         inode_info = ecryptfs_inode_to_private(inode);
144         mutex_lock(&inode_info->lower_file_mutex);
145         count = atomic_inc_return(&inode_info->lower_file_count);
146         if (WARN_ON_ONCE(count < 1))
147                 rc = -EINVAL;
148         else if (count == 1) {
149                 rc = ecryptfs_init_lower_file(dentry,
150                                               &inode_info->lower_file);
151                 if (rc)
152                         atomic_set(&inode_info->lower_file_count, 0);
153         }
154         mutex_unlock(&inode_info->lower_file_mutex);
155         return rc;
156 }
157
158 void ecryptfs_put_lower_file(struct inode *inode)
159 {
160         struct ecryptfs_inode_info *inode_info;
161
162         inode_info = ecryptfs_inode_to_private(inode);
163         if (atomic_dec_and_mutex_lock(&inode_info->lower_file_count,
164                                       &inode_info->lower_file_mutex)) {
165                 fput(inode_info->lower_file);
166                 inode_info->lower_file = NULL;
167                 mutex_unlock(&inode_info->lower_file_mutex);
168         }
169 }
170
171 enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig,
172        ecryptfs_opt_cipher, ecryptfs_opt_ecryptfs_cipher,
173        ecryptfs_opt_ecryptfs_key_bytes,
174        ecryptfs_opt_passthrough, ecryptfs_opt_xattr_metadata,
175        ecryptfs_opt_encrypted_view, ecryptfs_opt_fnek_sig,
176        ecryptfs_opt_fn_cipher, ecryptfs_opt_fn_cipher_key_bytes,
177        ecryptfs_opt_unlink_sigs, ecryptfs_opt_mount_auth_tok_only,
178        ecryptfs_opt_err };
179
180 static const match_table_t tokens = {
181         {ecryptfs_opt_sig, "sig=%s"},
182         {ecryptfs_opt_ecryptfs_sig, "ecryptfs_sig=%s"},
183         {ecryptfs_opt_cipher, "cipher=%s"},
184         {ecryptfs_opt_ecryptfs_cipher, "ecryptfs_cipher=%s"},
185         {ecryptfs_opt_ecryptfs_key_bytes, "ecryptfs_key_bytes=%u"},
186         {ecryptfs_opt_passthrough, "ecryptfs_passthrough"},
187         {ecryptfs_opt_xattr_metadata, "ecryptfs_xattr_metadata"},
188         {ecryptfs_opt_encrypted_view, "ecryptfs_encrypted_view"},
189         {ecryptfs_opt_fnek_sig, "ecryptfs_fnek_sig=%s"},
190         {ecryptfs_opt_fn_cipher, "ecryptfs_fn_cipher=%s"},
191         {ecryptfs_opt_fn_cipher_key_bytes, "ecryptfs_fn_key_bytes=%u"},
192         {ecryptfs_opt_unlink_sigs, "ecryptfs_unlink_sigs"},
193         {ecryptfs_opt_mount_auth_tok_only, "ecryptfs_mount_auth_tok_only"},
194         {ecryptfs_opt_err, NULL}
195 };
196
197 static int ecryptfs_init_global_auth_toks(
198         struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
199 {
200         struct ecryptfs_global_auth_tok *global_auth_tok;
201         struct ecryptfs_auth_tok *auth_tok;
202         int rc = 0;
203
204         list_for_each_entry(global_auth_tok,
205                             &mount_crypt_stat->global_auth_tok_list,
206                             mount_crypt_stat_list) {
207                 rc = ecryptfs_keyring_auth_tok_for_sig(
208                         &global_auth_tok->global_auth_tok_key, &auth_tok,
209                         global_auth_tok->sig);
210                 if (rc) {
211                         printk(KERN_ERR "Could not find valid key in user "
212                                "session keyring for sig specified in mount "
213                                "option: [%s]\n", global_auth_tok->sig);
214                         global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID;
215                         goto out;
216                 } else {
217                         global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID;
218                         up_write(&(global_auth_tok->global_auth_tok_key)->sem);
219                 }
220         }
221 out:
222         return rc;
223 }
224
225 static void ecryptfs_init_mount_crypt_stat(
226         struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
227 {
228         memset((void *)mount_crypt_stat, 0,
229                sizeof(struct ecryptfs_mount_crypt_stat));
230         INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list);
231         mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex);
232         mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED;
233 }
234
235 /**
236  * ecryptfs_parse_options
237  * @sb: The ecryptfs super block
238  * @options: The options passed to the kernel
239  *
240  * Parse mount options:
241  * debug=N         - ecryptfs_verbosity level for debug output
242  * sig=XXX         - description(signature) of the key to use
243  *
244  * Returns the dentry object of the lower-level (lower/interposed)
245  * directory; We want to mount our stackable file system on top of
246  * that lower directory.
247  *
248  * The signature of the key to use must be the description of a key
249  * already in the keyring. Mounting will fail if the key can not be
250  * found.
251  *
252  * Returns zero on success; non-zero on error
253  */
254 static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options)
255 {
256         char *p;
257         int rc = 0;
258         int sig_set = 0;
259         int cipher_name_set = 0;
260         int fn_cipher_name_set = 0;
261         int cipher_key_bytes;
262         int cipher_key_bytes_set = 0;
263         int fn_cipher_key_bytes;
264         int fn_cipher_key_bytes_set = 0;
265         struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
266                 &sbi->mount_crypt_stat;
267         substring_t args[MAX_OPT_ARGS];
268         int token;
269         char *sig_src;
270         char *cipher_name_dst;
271         char *cipher_name_src;
272         char *fn_cipher_name_dst;
273         char *fn_cipher_name_src;
274         char *fnek_dst;
275         char *fnek_src;
276         char *cipher_key_bytes_src;
277         char *fn_cipher_key_bytes_src;
278
279         if (!options) {
280                 rc = -EINVAL;
281                 goto out;
282         }
283         ecryptfs_init_mount_crypt_stat(mount_crypt_stat);
284         while ((p = strsep(&options, ",")) != NULL) {
285                 if (!*p)
286                         continue;
287                 token = match_token(p, tokens, args);
288                 switch (token) {
289                 case ecryptfs_opt_sig:
290                 case ecryptfs_opt_ecryptfs_sig:
291                         sig_src = args[0].from;
292                         rc = ecryptfs_add_global_auth_tok(mount_crypt_stat,
293                                                           sig_src, 0);
294                         if (rc) {
295                                 printk(KERN_ERR "Error attempting to register "
296                                        "global sig; rc = [%d]\n", rc);
297                                 goto out;
298                         }
299                         sig_set = 1;
300                         break;
301                 case ecryptfs_opt_cipher:
302                 case ecryptfs_opt_ecryptfs_cipher:
303                         cipher_name_src = args[0].from;
304                         cipher_name_dst =
305                                 mount_crypt_stat->
306                                 global_default_cipher_name;
307                         strncpy(cipher_name_dst, cipher_name_src,
308                                 ECRYPTFS_MAX_CIPHER_NAME_SIZE);
309                         cipher_name_dst[ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0';
310                         cipher_name_set = 1;
311                         break;
312                 case ecryptfs_opt_ecryptfs_key_bytes:
313                         cipher_key_bytes_src = args[0].from;
314                         cipher_key_bytes =
315                                 (int)simple_strtol(cipher_key_bytes_src,
316                                                    &cipher_key_bytes_src, 0);
317                         mount_crypt_stat->global_default_cipher_key_size =
318                                 cipher_key_bytes;
319                         cipher_key_bytes_set = 1;
320                         break;
321                 case ecryptfs_opt_passthrough:
322                         mount_crypt_stat->flags |=
323                                 ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED;
324                         break;
325                 case ecryptfs_opt_xattr_metadata:
326                         mount_crypt_stat->flags |=
327                                 ECRYPTFS_XATTR_METADATA_ENABLED;
328                         break;
329                 case ecryptfs_opt_encrypted_view:
330                         mount_crypt_stat->flags |=
331                                 ECRYPTFS_XATTR_METADATA_ENABLED;
332                         mount_crypt_stat->flags |=
333                                 ECRYPTFS_ENCRYPTED_VIEW_ENABLED;
334                         break;
335                 case ecryptfs_opt_fnek_sig:
336                         fnek_src = args[0].from;
337                         fnek_dst =
338                                 mount_crypt_stat->global_default_fnek_sig;
339                         strncpy(fnek_dst, fnek_src, ECRYPTFS_SIG_SIZE_HEX);
340                         mount_crypt_stat->global_default_fnek_sig[
341                                 ECRYPTFS_SIG_SIZE_HEX] = '\0';
342                         rc = ecryptfs_add_global_auth_tok(
343                                 mount_crypt_stat,
344                                 mount_crypt_stat->global_default_fnek_sig,
345                                 ECRYPTFS_AUTH_TOK_FNEK);
346                         if (rc) {
347                                 printk(KERN_ERR "Error attempting to register "
348                                        "global fnek sig [%s]; rc = [%d]\n",
349                                        mount_crypt_stat->global_default_fnek_sig,
350                                        rc);
351                                 goto out;
352                         }
353                         mount_crypt_stat->flags |=
354                                 (ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
355                                  | ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK);
356                         break;
357                 case ecryptfs_opt_fn_cipher:
358                         fn_cipher_name_src = args[0].from;
359                         fn_cipher_name_dst =
360                                 mount_crypt_stat->global_default_fn_cipher_name;
361                         strncpy(fn_cipher_name_dst, fn_cipher_name_src,
362                                 ECRYPTFS_MAX_CIPHER_NAME_SIZE);
363                         mount_crypt_stat->global_default_fn_cipher_name[
364                                 ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0';
365                         fn_cipher_name_set = 1;
366                         break;
367                 case ecryptfs_opt_fn_cipher_key_bytes:
368                         fn_cipher_key_bytes_src = args[0].from;
369                         fn_cipher_key_bytes =
370                                 (int)simple_strtol(fn_cipher_key_bytes_src,
371                                                    &fn_cipher_key_bytes_src, 0);
372                         mount_crypt_stat->global_default_fn_cipher_key_bytes =
373                                 fn_cipher_key_bytes;
374                         fn_cipher_key_bytes_set = 1;
375                         break;
376                 case ecryptfs_opt_unlink_sigs:
377                         mount_crypt_stat->flags |= ECRYPTFS_UNLINK_SIGS;
378                         break;
379                 case ecryptfs_opt_mount_auth_tok_only:
380                         mount_crypt_stat->flags |=
381                                 ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY;
382                         break;
383                 case ecryptfs_opt_err:
384                 default:
385                         printk(KERN_WARNING
386                                "%s: eCryptfs: unrecognized option [%s]\n",
387                                __func__, p);
388                 }
389         }
390         if (!sig_set) {
391                 rc = -EINVAL;
392                 ecryptfs_printk(KERN_ERR, "You must supply at least one valid "
393                                 "auth tok signature as a mount "
394                                 "parameter; see the eCryptfs README\n");
395                 goto out;
396         }
397         if (!cipher_name_set) {
398                 int cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER);
399
400                 BUG_ON(cipher_name_len >= ECRYPTFS_MAX_CIPHER_NAME_SIZE);
401                 strcpy(mount_crypt_stat->global_default_cipher_name,
402                        ECRYPTFS_DEFAULT_CIPHER);
403         }
404         if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
405             && !fn_cipher_name_set)
406                 strcpy(mount_crypt_stat->global_default_fn_cipher_name,
407                        mount_crypt_stat->global_default_cipher_name);
408         if (!cipher_key_bytes_set)
409                 mount_crypt_stat->global_default_cipher_key_size = 0;
410         if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
411             && !fn_cipher_key_bytes_set)
412                 mount_crypt_stat->global_default_fn_cipher_key_bytes =
413                         mount_crypt_stat->global_default_cipher_key_size;
414         mutex_lock(&key_tfm_list_mutex);
415         if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name,
416                                  NULL)) {
417                 rc = ecryptfs_add_new_key_tfm(
418                         NULL, mount_crypt_stat->global_default_cipher_name,
419                         mount_crypt_stat->global_default_cipher_key_size);
420                 if (rc) {
421                         printk(KERN_ERR "Error attempting to initialize "
422                                "cipher with name = [%s] and key size = [%td]; "
423                                "rc = [%d]\n",
424                                mount_crypt_stat->global_default_cipher_name,
425                                mount_crypt_stat->global_default_cipher_key_size,
426                                rc);
427                         rc = -EINVAL;
428                         mutex_unlock(&key_tfm_list_mutex);
429                         goto out;
430                 }
431         }
432         if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
433             && !ecryptfs_tfm_exists(
434                     mount_crypt_stat->global_default_fn_cipher_name, NULL)) {
435                 rc = ecryptfs_add_new_key_tfm(
436                         NULL, mount_crypt_stat->global_default_fn_cipher_name,
437                         mount_crypt_stat->global_default_fn_cipher_key_bytes);
438                 if (rc) {
439                         printk(KERN_ERR "Error attempting to initialize "
440                                "cipher with name = [%s] and key size = [%td]; "
441                                "rc = [%d]\n",
442                                mount_crypt_stat->global_default_fn_cipher_name,
443                                mount_crypt_stat->global_default_fn_cipher_key_bytes,
444                                rc);
445                         rc = -EINVAL;
446                         mutex_unlock(&key_tfm_list_mutex);
447                         goto out;
448                 }
449         }
450         mutex_unlock(&key_tfm_list_mutex);
451         rc = ecryptfs_init_global_auth_toks(mount_crypt_stat);
452         if (rc)
453                 printk(KERN_WARNING "One or more global auth toks could not "
454                        "properly register; rc = [%d]\n", rc);
455 out:
456         return rc;
457 }
458
459 struct kmem_cache *ecryptfs_sb_info_cache;
460 static struct file_system_type ecryptfs_fs_type;
461
462 /**
463  * ecryptfs_get_sb
464  * @fs_type
465  * @flags
466  * @dev_name: The path to mount over
467  * @raw_data: The options passed into the kernel
468  */
469 static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags,
470                         const char *dev_name, void *raw_data)
471 {
472         struct super_block *s;
473         struct ecryptfs_sb_info *sbi;
474         struct ecryptfs_dentry_info *root_info;
475         const char *err = "Getting sb failed";
476         struct inode *inode;
477         struct path path;
478         int rc;
479
480         sbi = kmem_cache_zalloc(ecryptfs_sb_info_cache, GFP_KERNEL);
481         if (!sbi) {
482                 rc = -ENOMEM;
483                 goto out;
484         }
485
486         rc = ecryptfs_parse_options(sbi, raw_data);
487         if (rc) {
488                 err = "Error parsing options";
489                 goto out;
490         }
491
492         s = sget(fs_type, NULL, set_anon_super, NULL);
493         if (IS_ERR(s)) {
494                 rc = PTR_ERR(s);
495                 goto out;
496         }
497
498         s->s_flags = flags;
499         rc = bdi_setup_and_register(&sbi->bdi, "ecryptfs", BDI_CAP_MAP_COPY);
500         if (rc)
501                 goto out1;
502
503         ecryptfs_set_superblock_private(s, sbi);
504         s->s_bdi = &sbi->bdi;
505
506         /* ->kill_sb() will take care of sbi after that point */
507         sbi = NULL;
508         s->s_op = &ecryptfs_sops;
509         s->s_d_op = &ecryptfs_dops;
510
511         err = "Reading sb failed";
512         rc = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path);
513         if (rc) {
514                 ecryptfs_printk(KERN_WARNING, "kern_path() failed\n");
515                 goto out1;
516         }
517         if (path.dentry->d_sb->s_type == &ecryptfs_fs_type) {
518                 rc = -EINVAL;
519                 printk(KERN_ERR "Mount on filesystem of type "
520                         "eCryptfs explicitly disallowed due to "
521                         "known incompatibilities\n");
522                 goto out_free;
523         }
524         ecryptfs_set_superblock_lower(s, path.dentry->d_sb);
525         s->s_maxbytes = path.dentry->d_sb->s_maxbytes;
526         s->s_blocksize = path.dentry->d_sb->s_blocksize;
527         s->s_magic = ECRYPTFS_SUPER_MAGIC;
528
529         inode = ecryptfs_get_inode(path.dentry->d_inode, s);
530         rc = PTR_ERR(inode);
531         if (IS_ERR(inode))
532                 goto out_free;
533
534         s->s_root = d_alloc_root(inode);
535         if (!s->s_root) {
536                 iput(inode);
537                 rc = -ENOMEM;
538                 goto out_free;
539         }
540
541         rc = -ENOMEM;
542         root_info = kmem_cache_zalloc(ecryptfs_dentry_info_cache, GFP_KERNEL);
543         if (!root_info)
544                 goto out_free;
545
546         /* ->kill_sb() will take care of root_info */
547         ecryptfs_set_dentry_private(s->s_root, root_info);
548         ecryptfs_set_dentry_lower(s->s_root, path.dentry);
549         ecryptfs_set_dentry_lower_mnt(s->s_root, path.mnt);
550
551         s->s_flags |= MS_ACTIVE;
552         return dget(s->s_root);
553
554 out_free:
555         path_put(&path);
556 out1:
557         deactivate_locked_super(s);
558 out:
559         if (sbi) {
560                 ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat);
561                 kmem_cache_free(ecryptfs_sb_info_cache, sbi);
562         }
563         printk(KERN_ERR "%s; rc = [%d]\n", err, rc);
564         return ERR_PTR(rc);
565 }
566
567 /**
568  * ecryptfs_kill_block_super
569  * @sb: The ecryptfs super block
570  *
571  * Used to bring the superblock down and free the private data.
572  */
573 static void ecryptfs_kill_block_super(struct super_block *sb)
574 {
575         struct ecryptfs_sb_info *sb_info = ecryptfs_superblock_to_private(sb);
576         kill_anon_super(sb);
577         if (!sb_info)
578                 return;
579         ecryptfs_destroy_mount_crypt_stat(&sb_info->mount_crypt_stat);
580         bdi_destroy(&sb_info->bdi);
581         kmem_cache_free(ecryptfs_sb_info_cache, sb_info);
582 }
583
584 static struct file_system_type ecryptfs_fs_type = {
585         .owner = THIS_MODULE,
586         .name = "ecryptfs",
587         .mount = ecryptfs_mount,
588         .kill_sb = ecryptfs_kill_block_super,
589         .fs_flags = 0
590 };
591
592 /**
593  * inode_info_init_once
594  *
595  * Initializes the ecryptfs_inode_info_cache when it is created
596  */
597 static void
598 inode_info_init_once(void *vptr)
599 {
600         struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr;
601
602         inode_init_once(&ei->vfs_inode);
603 }
604
605 static struct ecryptfs_cache_info {
606         struct kmem_cache **cache;
607         const char *name;
608         size_t size;
609         void (*ctor)(void *obj);
610 } ecryptfs_cache_infos[] = {
611         {
612                 .cache = &ecryptfs_auth_tok_list_item_cache,
613                 .name = "ecryptfs_auth_tok_list_item",
614                 .size = sizeof(struct ecryptfs_auth_tok_list_item),
615         },
616         {
617                 .cache = &ecryptfs_file_info_cache,
618                 .name = "ecryptfs_file_cache",
619                 .size = sizeof(struct ecryptfs_file_info),
620         },
621         {
622                 .cache = &ecryptfs_dentry_info_cache,
623                 .name = "ecryptfs_dentry_info_cache",
624                 .size = sizeof(struct ecryptfs_dentry_info),
625         },
626         {
627                 .cache = &ecryptfs_inode_info_cache,
628                 .name = "ecryptfs_inode_cache",
629                 .size = sizeof(struct ecryptfs_inode_info),
630                 .ctor = inode_info_init_once,
631         },
632         {
633                 .cache = &ecryptfs_sb_info_cache,
634                 .name = "ecryptfs_sb_cache",
635                 .size = sizeof(struct ecryptfs_sb_info),
636         },
637         {
638                 .cache = &ecryptfs_header_cache,
639                 .name = "ecryptfs_headers",
640                 .size = PAGE_CACHE_SIZE,
641         },
642         {
643                 .cache = &ecryptfs_xattr_cache,
644                 .name = "ecryptfs_xattr_cache",
645                 .size = PAGE_CACHE_SIZE,
646         },
647         {
648                 .cache = &ecryptfs_key_record_cache,
649                 .name = "ecryptfs_key_record_cache",
650                 .size = sizeof(struct ecryptfs_key_record),
651         },
652         {
653                 .cache = &ecryptfs_key_sig_cache,
654                 .name = "ecryptfs_key_sig_cache",
655                 .size = sizeof(struct ecryptfs_key_sig),
656         },
657         {
658                 .cache = &ecryptfs_global_auth_tok_cache,
659                 .name = "ecryptfs_global_auth_tok_cache",
660                 .size = sizeof(struct ecryptfs_global_auth_tok),
661         },
662         {
663                 .cache = &ecryptfs_key_tfm_cache,
664                 .name = "ecryptfs_key_tfm_cache",
665                 .size = sizeof(struct ecryptfs_key_tfm),
666         },
667         {
668                 .cache = &ecryptfs_open_req_cache,
669                 .name = "ecryptfs_open_req_cache",
670                 .size = sizeof(struct ecryptfs_open_req),
671         },
672 };
673
674 static void ecryptfs_free_kmem_caches(void)
675 {
676         int i;
677
678         for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
679                 struct ecryptfs_cache_info *info;
680
681                 info = &ecryptfs_cache_infos[i];
682                 if (*(info->cache))
683                         kmem_cache_destroy(*(info->cache));
684         }
685 }
686
687 /**
688  * ecryptfs_init_kmem_caches
689  *
690  * Returns zero on success; non-zero otherwise
691  */
692 static int ecryptfs_init_kmem_caches(void)
693 {
694         int i;
695
696         for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
697                 struct ecryptfs_cache_info *info;
698
699                 info = &ecryptfs_cache_infos[i];
700                 *(info->cache) = kmem_cache_create(info->name, info->size,
701                                 0, SLAB_HWCACHE_ALIGN, info->ctor);
702                 if (!*(info->cache)) {
703                         ecryptfs_free_kmem_caches();
704                         ecryptfs_printk(KERN_WARNING, "%s: "
705                                         "kmem_cache_create failed\n",
706                                         info->name);
707                         return -ENOMEM;
708                 }
709         }
710         return 0;
711 }
712
713 static struct kobject *ecryptfs_kobj;
714
715 static ssize_t version_show(struct kobject *kobj,
716                             struct kobj_attribute *attr, char *buff)
717 {
718         return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK);
719 }
720
721 static struct kobj_attribute version_attr = __ATTR_RO(version);
722
723 static struct attribute *attributes[] = {
724         &version_attr.attr,
725         NULL,
726 };
727
728 static struct attribute_group attr_group = {
729         .attrs = attributes,
730 };
731
732 static int do_sysfs_registration(void)
733 {
734         int rc;
735
736         ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj);
737         if (!ecryptfs_kobj) {
738                 printk(KERN_ERR "Unable to create ecryptfs kset\n");
739                 rc = -ENOMEM;
740                 goto out;
741         }
742         rc = sysfs_create_group(ecryptfs_kobj, &attr_group);
743         if (rc) {
744                 printk(KERN_ERR
745                        "Unable to create ecryptfs version attributes\n");
746                 kobject_put(ecryptfs_kobj);
747         }
748 out:
749         return rc;
750 }
751
752 static void do_sysfs_unregistration(void)
753 {
754         sysfs_remove_group(ecryptfs_kobj, &attr_group);
755         kobject_put(ecryptfs_kobj);
756 }
757
758 static int __init ecryptfs_init(void)
759 {
760         int rc;
761
762         if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_CACHE_SIZE) {
763                 rc = -EINVAL;
764                 ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is "
765                                 "larger than the host's page size, and so "
766                                 "eCryptfs cannot run on this system. The "
767                                 "default eCryptfs extent size is [%u] bytes; "
768                                 "the page size is [%lu] bytes.\n",
769                                 ECRYPTFS_DEFAULT_EXTENT_SIZE,
770                                 (unsigned long)PAGE_CACHE_SIZE);
771                 goto out;
772         }
773         rc = ecryptfs_init_kmem_caches();
774         if (rc) {
775                 printk(KERN_ERR
776                        "Failed to allocate one or more kmem_cache objects\n");
777                 goto out;
778         }
779         rc = register_filesystem(&ecryptfs_fs_type);
780         if (rc) {
781                 printk(KERN_ERR "Failed to register filesystem\n");
782                 goto out_free_kmem_caches;
783         }
784         rc = do_sysfs_registration();
785         if (rc) {
786                 printk(KERN_ERR "sysfs registration failed\n");
787                 goto out_unregister_filesystem;
788         }
789         rc = ecryptfs_init_kthread();
790         if (rc) {
791                 printk(KERN_ERR "%s: kthread initialization failed; "
792                        "rc = [%d]\n", __func__, rc);
793                 goto out_do_sysfs_unregistration;
794         }
795         rc = ecryptfs_init_messaging();
796         if (rc) {
797                 printk(KERN_ERR "Failure occurred while attempting to "
798                                 "initialize the communications channel to "
799                                 "ecryptfsd\n");
800                 goto out_destroy_kthread;
801         }
802         rc = ecryptfs_init_crypto();
803         if (rc) {
804                 printk(KERN_ERR "Failure whilst attempting to init crypto; "
805                        "rc = [%d]\n", rc);
806                 goto out_release_messaging;
807         }
808         if (ecryptfs_verbosity > 0)
809                 printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values "
810                         "will be written to the syslog!\n", ecryptfs_verbosity);
811
812         goto out;
813 out_release_messaging:
814         ecryptfs_release_messaging();
815 out_destroy_kthread:
816         ecryptfs_destroy_kthread();
817 out_do_sysfs_unregistration:
818         do_sysfs_unregistration();
819 out_unregister_filesystem:
820         unregister_filesystem(&ecryptfs_fs_type);
821 out_free_kmem_caches:
822         ecryptfs_free_kmem_caches();
823 out:
824         return rc;
825 }
826
827 static void __exit ecryptfs_exit(void)
828 {
829         int rc;
830
831         rc = ecryptfs_destroy_crypto();
832         if (rc)
833                 printk(KERN_ERR "Failure whilst attempting to destroy crypto; "
834                        "rc = [%d]\n", rc);
835         ecryptfs_release_messaging();
836         ecryptfs_destroy_kthread();
837         do_sysfs_unregistration();
838         unregister_filesystem(&ecryptfs_fs_type);
839         ecryptfs_free_kmem_caches();
840 }
841
842 MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>");
843 MODULE_DESCRIPTION("eCryptfs");
844
845 MODULE_LICENSE("GPL");
846
847 module_init(ecryptfs_init)
848 module_exit(ecryptfs_exit)