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 static struct inode *ecryptfs_get_inode(struct inode *lower_inode,
 145                        struct super_block *sb)
 146 {
 147         struct inode *inode;
 148         int rc = 0;
 149
 150         if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb)) {
 151                 rc = -EXDEV;
 152                 goto out;
 153         }
 154         if (!igrab(lower_inode)) {
 155                 rc = -ESTALE;
 156                 goto out;
 157         }
 158         inode = iget5_locked(sb, (unsigned long)lower_inode,
 159                              ecryptfs_inode_test, ecryptfs_inode_set,
 160                              lower_inode);
 161         if (!inode) {
 162                 rc = -EACCES;
 163                 iput(lower_inode);
 164                 goto out;
 165         }
 166         if (inode->i_state & I_NEW)
 167                 unlock_new_inode(inode);
 168         else
 169                 iput(lower_inode);
 170         if (S_ISLNK(lower_inode->i_mode))
 171                 inode->i_op = &ecryptfs_symlink_iops;
 172         else if (S_ISDIR(lower_inode->i_mode))
 173                 inode->i_op = &ecryptfs_dir_iops;
 174         if (S_ISDIR(lower_inode->i_mode))
 175                 inode->i_fop = &ecryptfs_dir_fops;
 176         if (special_file(lower_inode->i_mode))
 177                 init_special_inode(inode, lower_inode->i_mode,
 178                                    lower_inode->i_rdev);
 179         fsstack_copy_attr_all(inode, lower_inode);
 180         /* This size will be overwritten for real files w/ headers and
 181          * other metadata */
 182         fsstack_copy_inode_size(inode, lower_inode);
 183         return inode;
 184 out:
 185         return ERR_PTR(rc);
 186 }
 187
 188 /**
 189  * ecryptfs_interpose
 190  * @lower_dentry: Existing dentry in the lower filesystem
 191  * @dentry: ecryptfs' dentry
 192  * @sb: ecryptfs's super_block
 193  * @flags: flags to govern behavior of interpose procedure
 194  *
 195  * Interposes upper and lower dentries.
 196  *
 197  * Returns zero on success; non-zero otherwise
 198  */
 199 int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry,
 200                        struct super_block *sb, u32 flags)
 201 {
 202         struct inode *lower_inode = lower_dentry->d_inode;
 203         struct inode *inode = ecryptfs_get_inode(lower_inode, sb);
 204         if (IS_ERR(inode))
 205                 return PTR_ERR(inode);
 206         if (flags & ECRYPTFS_INTERPOSE_FLAG_D_ADD)
 207                 d_add(dentry, inode);
 208         else
 209                 d_instantiate(dentry, inode);
 210         return 0;
 211 }
 212
 213 enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig,
 214        ecryptfs_opt_cipher, ecryptfs_opt_ecryptfs_cipher,
 215        ecryptfs_opt_ecryptfs_key_bytes,
 216        ecryptfs_opt_passthrough, ecryptfs_opt_xattr_metadata,
 217        ecryptfs_opt_encrypted_view, ecryptfs_opt_fnek_sig,
 218        ecryptfs_opt_fn_cipher, ecryptfs_opt_fn_cipher_key_bytes,
 219        ecryptfs_opt_unlink_sigs, ecryptfs_opt_mount_auth_tok_only,
 220        ecryptfs_opt_err };
 221
 222 static const match_table_t tokens = {
 223         {ecryptfs_opt_sig, "sig=%s"},
 224         {ecryptfs_opt_ecryptfs_sig, "ecryptfs_sig=%s"},
 225         {ecryptfs_opt_cipher, "cipher=%s"},
 226         {ecryptfs_opt_ecryptfs_cipher, "ecryptfs_cipher=%s"},
 227         {ecryptfs_opt_ecryptfs_key_bytes, "ecryptfs_key_bytes=%u"},
 228         {ecryptfs_opt_passthrough, "ecryptfs_passthrough"},
 229         {ecryptfs_opt_xattr_metadata, "ecryptfs_xattr_metadata"},
 230         {ecryptfs_opt_encrypted_view, "ecryptfs_encrypted_view"},
 231         {ecryptfs_opt_fnek_sig, "ecryptfs_fnek_sig=%s"},
 232         {ecryptfs_opt_fn_cipher, "ecryptfs_fn_cipher=%s"},
 233         {ecryptfs_opt_fn_cipher_key_bytes, "ecryptfs_fn_key_bytes=%u"},
 234         {ecryptfs_opt_unlink_sigs, "ecryptfs_unlink_sigs"},
 235         {ecryptfs_opt_mount_auth_tok_only, "ecryptfs_mount_auth_tok_only"},
 236         {ecryptfs_opt_err, NULL}
 237 };
 238
 239 static int ecryptfs_init_global_auth_toks(
 240         struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
 241 {
 242         struct ecryptfs_global_auth_tok *global_auth_tok;
 243         int rc = 0;
 244
 245         list_for_each_entry(global_auth_tok,
 246                             &mount_crypt_stat->global_auth_tok_list,
 247                             mount_crypt_stat_list) {
 248                 rc = ecryptfs_keyring_auth_tok_for_sig(
 249                         &global_auth_tok->global_auth_tok_key,
 250                         &global_auth_tok->global_auth_tok,
 251                         global_auth_tok->sig);
 252                 if (rc) {
 253                         printk(KERN_ERR "Could not find valid key in user "
 254                                "session keyring for sig specified in mount "
 255                                "option: [%s]\n", global_auth_tok->sig);
 256                         global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID;
 257                         goto out;
 258                 } else
 259                         global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID;
 260         }
 261 out:
 262         return rc;
 263 }
 264
 265 static void ecryptfs_init_mount_crypt_stat(
 266         struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
 267 {
 268         memset((void *)mount_crypt_stat, 0,
 269                sizeof(struct ecryptfs_mount_crypt_stat));
 270         INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list);
 271         mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex);
 272         mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED;
 273 }
 274
 275 /**
 276  * ecryptfs_parse_options
 277  * @sb: The ecryptfs super block
 278  * @options: The options pased to the kernel
 279  *
 280  * Parse mount options:
 281  * debug=N         - ecryptfs_verbosity level for debug output
 282  * sig=XXX         - description(signature) of the key to use
 283  *
 284  * Returns the dentry object of the lower-level (lower/interposed)
 285  * directory; We want to mount our stackable file system on top of
 286  * that lower directory.
 287  *
 288  * The signature of the key to use must be the description of a key
 289  * already in the keyring. Mounting will fail if the key can not be
 290  * found.
 291  *
 292  * Returns zero on success; non-zero on error
 293  */
 294 static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options)
 295 {
 296         char *p;
 297         int rc = 0;
 298         int sig_set = 0;
 299         int cipher_name_set = 0;
 300         int fn_cipher_name_set = 0;
 301         int cipher_key_bytes;
 302         int cipher_key_bytes_set = 0;
 303         int fn_cipher_key_bytes;
 304         int fn_cipher_key_bytes_set = 0;
 305         struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
 306                 &sbi->mount_crypt_stat;
 307         substring_t args[MAX_OPT_ARGS];
 308         int token;
 309         char *sig_src;
 310         char *cipher_name_dst;
 311         char *cipher_name_src;
 312         char *fn_cipher_name_dst;
 313         char *fn_cipher_name_src;
 314         char *fnek_dst;
 315         char *fnek_src;
 316         char *cipher_key_bytes_src;
 317         char *fn_cipher_key_bytes_src;
 318
 319         if (!options) {
 320                 rc = -EINVAL;
 321                 goto out;
 322         }
 323         ecryptfs_init_mount_crypt_stat(mount_crypt_stat);
 324         while ((p = strsep(&options, ",")) != NULL) {
 325                 if (!*p)
 326                         continue;
 327                 token = match_token(p, tokens, args);
 328                 switch (token) {
 329                 case ecryptfs_opt_sig:
 330                 case ecryptfs_opt_ecryptfs_sig:
 331                         sig_src = args[0].from;
 332                         rc = ecryptfs_add_global_auth_tok(mount_crypt_stat,
 333                                                           sig_src, 0);
 334                         if (rc) {
 335                                 printk(KERN_ERR "Error attempting to register "
 336                                        "global sig; rc = [%d]\n", rc);
 337                                 goto out;
 338                         }
 339                         sig_set = 1;
 340                         break;
 341                 case ecryptfs_opt_cipher:
 342                 case ecryptfs_opt_ecryptfs_cipher:
 343                         cipher_name_src = args[0].from;
 344                         cipher_name_dst =
 345                                 mount_crypt_stat->
 346                                 global_default_cipher_name;
 347                         strncpy(cipher_name_dst, cipher_name_src,
 348                                 ECRYPTFS_MAX_CIPHER_NAME_SIZE);
 349                         cipher_name_dst[ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0';
 350                         cipher_name_set = 1;
 351                         break;
 352                 case ecryptfs_opt_ecryptfs_key_bytes:
 353                         cipher_key_bytes_src = args[0].from;
 354                         cipher_key_bytes =
 355                                 (int)simple_strtol(cipher_key_bytes_src,
 356                                                    &cipher_key_bytes_src, 0);
 357                         mount_crypt_stat->global_default_cipher_key_size =
 358                                 cipher_key_bytes;
 359                         cipher_key_bytes_set = 1;
 360                         break;
 361                 case ecryptfs_opt_passthrough:
 362                         mount_crypt_stat->flags |=
 363                                 ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED;
 364                         break;
 365                 case ecryptfs_opt_xattr_metadata:
 366                         mount_crypt_stat->flags |=
 367                                 ECRYPTFS_XATTR_METADATA_ENABLED;
 368                         break;
 369                 case ecryptfs_opt_encrypted_view:
 370                         mount_crypt_stat->flags |=
 371                                 ECRYPTFS_XATTR_METADATA_ENABLED;
 372                         mount_crypt_stat->flags |=
 373                                 ECRYPTFS_ENCRYPTED_VIEW_ENABLED;
 374                         break;
 375                 case ecryptfs_opt_fnek_sig:
 376                         fnek_src = args[0].from;
 377                         fnek_dst =
 378                                 mount_crypt_stat->global_default_fnek_sig;
 379                         strncpy(fnek_dst, fnek_src, ECRYPTFS_SIG_SIZE_HEX);
 380                         mount_crypt_stat->global_default_fnek_sig[
 381                                 ECRYPTFS_SIG_SIZE_HEX] = '\0';
 382                         rc = ecryptfs_add_global_auth_tok(
 383                                 mount_crypt_stat,
 384                                 mount_crypt_stat->global_default_fnek_sig,
 385                                 ECRYPTFS_AUTH_TOK_FNEK);
 386                         if (rc) {
 387                                 printk(KERN_ERR "Error attempting to register "
 388                                        "global fnek sig [%s]; rc = [%d]\n",
 389                                        mount_crypt_stat->global_default_fnek_sig,
 390                                        rc);
 391                                 goto out;
 392                         }
 393                         mount_crypt_stat->flags |=
 394                                 (ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
 395                                  | ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK);
 396                         break;
 397                 case ecryptfs_opt_fn_cipher:
 398                         fn_cipher_name_src = args[0].from;
 399                         fn_cipher_name_dst =
 400                                 mount_crypt_stat->global_default_fn_cipher_name;
 401                         strncpy(fn_cipher_name_dst, fn_cipher_name_src,
 402                                 ECRYPTFS_MAX_CIPHER_NAME_SIZE);
 403                         mount_crypt_stat->global_default_fn_cipher_name[
 404                                 ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0';
 405                         fn_cipher_name_set = 1;
 406                         break;
 407                 case ecryptfs_opt_fn_cipher_key_bytes:
 408                         fn_cipher_key_bytes_src = args[0].from;
 409                         fn_cipher_key_bytes =
 410                                 (int)simple_strtol(fn_cipher_key_bytes_src,
 411                                                    &fn_cipher_key_bytes_src, 0);
 412                         mount_crypt_stat->global_default_fn_cipher_key_bytes =
 413                                 fn_cipher_key_bytes;
 414                         fn_cipher_key_bytes_set = 1;
 415                         break;
 416                 case ecryptfs_opt_unlink_sigs:
 417                         mount_crypt_stat->flags |= ECRYPTFS_UNLINK_SIGS;
 418                         break;
 419                 case ecryptfs_opt_mount_auth_tok_only:
 420                         mount_crypt_stat->flags |=
 421                                 ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY;
 422                         break;
 423                 case ecryptfs_opt_err:
 424                 default:
 425                         printk(KERN_WARNING
 426                                "%s: eCryptfs: unrecognized option [%s]\n",
 427                                __func__, p);
 428                 }
 429         }
 430         if (!sig_set) {
 431                 rc = -EINVAL;
 432                 ecryptfs_printk(KERN_ERR, "You must supply at least one valid "
 433                                 "auth tok signature as a mount "
 434                                 "parameter; see the eCryptfs README\n");
 435                 goto out;
 436         }
 437         if (!cipher_name_set) {
 438                 int cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER);
 439
 440                 BUG_ON(cipher_name_len >= ECRYPTFS_MAX_CIPHER_NAME_SIZE);
 441                 strcpy(mount_crypt_stat->global_default_cipher_name,
 442                        ECRYPTFS_DEFAULT_CIPHER);
 443         }
 444         if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
 445             && !fn_cipher_name_set)
 446                 strcpy(mount_crypt_stat->global_default_fn_cipher_name,
 447                        mount_crypt_stat->global_default_cipher_name);
 448         if (!cipher_key_bytes_set)
 449                 mount_crypt_stat->global_default_cipher_key_size = 0;
 450         if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
 451             && !fn_cipher_key_bytes_set)
 452                 mount_crypt_stat->global_default_fn_cipher_key_bytes =
 453                         mount_crypt_stat->global_default_cipher_key_size;
 454         mutex_lock(&key_tfm_list_mutex);
 455         if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name,
 456                                  NULL)) {
 457                 rc = ecryptfs_add_new_key_tfm(
 458                         NULL, mount_crypt_stat->global_default_cipher_name,
 459                         mount_crypt_stat->global_default_cipher_key_size);
 460                 if (rc) {
 461                         printk(KERN_ERR "Error attempting to initialize "
 462                                "cipher with name = [%s] and key size = [%td]; "
 463                                "rc = [%d]\n",
 464                                mount_crypt_stat->global_default_cipher_name,
 465                                mount_crypt_stat->global_default_cipher_key_size,
 466                                rc);
 467                         rc = -EINVAL;
 468                         mutex_unlock(&key_tfm_list_mutex);
 469                         goto out;
 470                 }
 471         }
 472         if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
 473             && !ecryptfs_tfm_exists(
 474                     mount_crypt_stat->global_default_fn_cipher_name, NULL)) {
 475                 rc = ecryptfs_add_new_key_tfm(
 476                         NULL, mount_crypt_stat->global_default_fn_cipher_name,
 477                         mount_crypt_stat->global_default_fn_cipher_key_bytes);
 478                 if (rc) {
 479                         printk(KERN_ERR "Error attempting to initialize "
 480                                "cipher with name = [%s] and key size = [%td]; "
 481                                "rc = [%d]\n",
 482                                mount_crypt_stat->global_default_fn_cipher_name,
 483                                mount_crypt_stat->global_default_fn_cipher_key_bytes,
 484                                rc);
 485                         rc = -EINVAL;
 486                         mutex_unlock(&key_tfm_list_mutex);
 487                         goto out;
 488                 }
 489         }
 490         mutex_unlock(&key_tfm_list_mutex);
 491         rc = ecryptfs_init_global_auth_toks(mount_crypt_stat);
 492         if (rc)
 493                 printk(KERN_WARNING "One or more global auth toks could not "
 494                        "properly register; rc = [%d]\n", rc);
 495 out:
 496         return rc;
 497 }
 498
 499 struct kmem_cache *ecryptfs_sb_info_cache;
 500 static struct file_system_type ecryptfs_fs_type;
 501
 502 /**
 503  * ecryptfs_get_sb
 504  * @fs_type
 505  * @flags
 506  * @dev_name: The path to mount over
 507  * @raw_data: The options passed into the kernel
 508  */
 509 static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags,
 510                         const char *dev_name, void *raw_data)
 511 {
 512         struct super_block *s;
 513         struct ecryptfs_sb_info *sbi;
 514         struct ecryptfs_dentry_info *root_info;
 515         const char *err = "Getting sb failed";
 516         struct inode *inode;
 517         struct path path;
 518         int rc;
 519
 520         sbi = kmem_cache_zalloc(ecryptfs_sb_info_cache, GFP_KERNEL);
 521         if (!sbi) {
 522                 rc = -ENOMEM;
 523                 goto out;
 524         }
 525
 526         rc = ecryptfs_parse_options(sbi, raw_data);
 527         if (rc) {
 528                 err = "Error parsing options";
 529                 goto out;
 530         }
 531
 532         s = sget(fs_type, NULL, set_anon_super, NULL);
 533         if (IS_ERR(s)) {
 534                 rc = PTR_ERR(s);
 535                 goto out;
 536         }
 537
 538         s->s_flags = flags;
 539         rc = bdi_setup_and_register(&sbi->bdi, "ecryptfs", BDI_CAP_MAP_COPY);
 540         if (rc)
 541                 goto out1;
 542
 543         ecryptfs_set_superblock_private(s, sbi);
 544         s->s_bdi = &sbi->bdi;
 545
 546         /* ->kill_sb() will take care of sbi after that point */
 547         sbi = NULL;
 548         s->s_op = &ecryptfs_sops;
 549         s->s_d_op = &ecryptfs_dops;
 550
 551         err = "Reading sb failed";
 552         rc = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path);
 553         if (rc) {
 554                 ecryptfs_printk(KERN_WARNING, "kern_path() failed\n");
 555                 goto out1;
 556         }
 557         if (path.dentry->d_sb->s_type == &ecryptfs_fs_type) {
 558                 rc = -EINVAL;
 559                 printk(KERN_ERR "Mount on filesystem of type "
 560                         "eCryptfs explicitly disallowed due to "
 561                         "known incompatibilities\n");
 562                 goto out_free;
 563         }
 564         ecryptfs_set_superblock_lower(s, path.dentry->d_sb);
 565         s->s_maxbytes = path.dentry->d_sb->s_maxbytes;
 566         s->s_blocksize = path.dentry->d_sb->s_blocksize;
 567
 568         inode = ecryptfs_get_inode(path.dentry->d_inode, s);
 569         rc = PTR_ERR(inode);
 570         if (IS_ERR(inode))
 571                 goto out_free;
 572
 573         s->s_root = d_alloc_root(inode);
 574         if (!s->s_root) {
 575                 iput(inode);
 576                 rc = -ENOMEM;
 577                 goto out_free;
 578         }
 579
 580         rc = -ENOMEM;
 581         root_info = kmem_cache_zalloc(ecryptfs_dentry_info_cache, GFP_KERNEL);
 582         if (!root_info)
 583                 goto out_free;
 584
 585         /* ->kill_sb() will take care of root_info */
 586         ecryptfs_set_dentry_private(s->s_root, root_info);
 587         ecryptfs_set_dentry_lower(s->s_root, path.dentry);
 588         ecryptfs_set_dentry_lower_mnt(s->s_root, path.mnt);
 589
 590         s->s_flags |= MS_ACTIVE;
 591         return dget(s->s_root);
 592
 593 out_free:
 594         path_put(&path);
 595 out1:
 596         deactivate_locked_super(s);
 597 out:
 598         if (sbi) {
 599                 ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat);
 600                 kmem_cache_free(ecryptfs_sb_info_cache, sbi);
 601         }
 602         printk(KERN_ERR "%s; rc = [%d]\n", err, rc);
 603         return ERR_PTR(rc);
 604 }
 605
 606 /**
 607  * ecryptfs_kill_block_super
 608  * @sb: The ecryptfs super block
 609  *
 610  * Used to bring the superblock down and free the private data.
 611  */
 612 static void ecryptfs_kill_block_super(struct super_block *sb)
 613 {
 614         struct ecryptfs_sb_info *sb_info = ecryptfs_superblock_to_private(sb);
 615         kill_anon_super(sb);
 616         if (!sb_info)
 617                 return;
 618         ecryptfs_destroy_mount_crypt_stat(&sb_info->mount_crypt_stat);
 619         bdi_destroy(&sb_info->bdi);
 620         kmem_cache_free(ecryptfs_sb_info_cache, sb_info);
 621 }
 622
 623 static struct file_system_type ecryptfs_fs_type = {
 624         .owner = THIS_MODULE,
 625         .name = "ecryptfs",
 626         .mount = ecryptfs_mount,
 627         .kill_sb = ecryptfs_kill_block_super,
 628         .fs_flags = 0
 629 };
 630
 631 /**
 632  * inode_info_init_once
 633  *
 634  * Initializes the ecryptfs_inode_info_cache when it is created
 635  */
 636 static void
 637 inode_info_init_once(void *vptr)
 638 {
 639         struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr;
 640
 641         inode_init_once(&ei->vfs_inode);
 642 }
 643
 644 static struct ecryptfs_cache_info {
 645         struct kmem_cache **cache;
 646         const char *name;
 647         size_t size;
 648         void (*ctor)(void *obj);
 649 } ecryptfs_cache_infos[] = {
 650         {
 651                 .cache = &ecryptfs_auth_tok_list_item_cache,
 652                 .name = "ecryptfs_auth_tok_list_item",
 653                 .size = sizeof(struct ecryptfs_auth_tok_list_item),
 654         },
 655         {
 656                 .cache = &ecryptfs_file_info_cache,
 657                 .name = "ecryptfs_file_cache",
 658                 .size = sizeof(struct ecryptfs_file_info),
 659         },
 660         {
 661                 .cache = &ecryptfs_dentry_info_cache,
 662                 .name = "ecryptfs_dentry_info_cache",
 663                 .size = sizeof(struct ecryptfs_dentry_info),
 664         },
 665         {
 666                 .cache = &ecryptfs_inode_info_cache,
 667                 .name = "ecryptfs_inode_cache",
 668                 .size = sizeof(struct ecryptfs_inode_info),
 669                 .ctor = inode_info_init_once,
 670         },
 671         {
 672                 .cache = &ecryptfs_sb_info_cache,
 673                 .name = "ecryptfs_sb_cache",
 674                 .size = sizeof(struct ecryptfs_sb_info),
 675         },
 676         {
 677                 .cache = &ecryptfs_header_cache_1,
 678                 .name = "ecryptfs_headers_1",
 679                 .size = PAGE_CACHE_SIZE,
 680         },
 681         {
 682                 .cache = &ecryptfs_header_cache_2,
 683                 .name = "ecryptfs_headers_2",
 684                 .size = PAGE_CACHE_SIZE,
 685         },
 686         {
 687                 .cache = &ecryptfs_xattr_cache,
 688                 .name = "ecryptfs_xattr_cache",
 689                 .size = PAGE_CACHE_SIZE,
 690         },
 691         {
 692                 .cache = &ecryptfs_key_record_cache,
 693                 .name = "ecryptfs_key_record_cache",
 694                 .size = sizeof(struct ecryptfs_key_record),
 695         },
 696         {
 697                 .cache = &ecryptfs_key_sig_cache,
 698                 .name = "ecryptfs_key_sig_cache",
 699                 .size = sizeof(struct ecryptfs_key_sig),
 700         },
 701         {
 702                 .cache = &ecryptfs_global_auth_tok_cache,
 703                 .name = "ecryptfs_global_auth_tok_cache",
 704                 .size = sizeof(struct ecryptfs_global_auth_tok),
 705         },
 706         {
 707                 .cache = &ecryptfs_key_tfm_cache,
 708                 .name = "ecryptfs_key_tfm_cache",
 709                 .size = sizeof(struct ecryptfs_key_tfm),
 710         },
 711         {
 712                 .cache = &ecryptfs_open_req_cache,
 713                 .name = "ecryptfs_open_req_cache",
 714                 .size = sizeof(struct ecryptfs_open_req),
 715         },
 716 };
 717
 718 static void ecryptfs_free_kmem_caches(void)
 719 {
 720         int i;
 721
 722         for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
 723                 struct ecryptfs_cache_info *info;
 724
 725                 info = &ecryptfs_cache_infos[i];
 726                 if (*(info->cache))
 727                         kmem_cache_destroy(*(info->cache));
 728         }
 729 }
 730
 731 /**
 732  * ecryptfs_init_kmem_caches
 733  *
 734  * Returns zero on success; non-zero otherwise
 735  */
 736 static int ecryptfs_init_kmem_caches(void)
 737 {
 738         int i;
 739
 740         for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
 741                 struct ecryptfs_cache_info *info;
 742
 743                 info = &ecryptfs_cache_infos[i];
 744                 *(info->cache) = kmem_cache_create(info->name, info->size,
 745                                 0, SLAB_HWCACHE_ALIGN, info->ctor);
 746                 if (!*(info->cache)) {
 747                         ecryptfs_free_kmem_caches();
 748                         ecryptfs_printk(KERN_WARNING, "%s: "
 749                                         "kmem_cache_create failed\n",
 750                                         info->name);
 751                         return -ENOMEM;
 752                 }
 753         }
 754         return 0;
 755 }
 756
 757 static struct kobject *ecryptfs_kobj;
 758
 759 static ssize_t version_show(struct kobject *kobj,
 760                             struct kobj_attribute *attr, char *buff)
 761 {
 762         return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK);
 763 }
 764
 765 static struct kobj_attribute version_attr = __ATTR_RO(version);
 766
 767 static struct attribute *attributes[] = {
 768         &version_attr.attr,
 769         NULL,
 770 };
 771
 772 static struct attribute_group attr_group = {
 773         .attrs = attributes,
 774 };
 775
 776 static int do_sysfs_registration(void)
 777 {
 778         int rc;
 779
 780         ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj);
 781         if (!ecryptfs_kobj) {
 782                 printk(KERN_ERR "Unable to create ecryptfs kset\n");
 783                 rc = -ENOMEM;
 784                 goto out;
 785         }
 786         rc = sysfs_create_group(ecryptfs_kobj, &attr_group);
 787         if (rc) {
 788                 printk(KERN_ERR
 789                        "Unable to create ecryptfs version attributes\n");
 790                 kobject_put(ecryptfs_kobj);
 791         }
 792 out:
 793         return rc;
 794 }
 795
 796 static void do_sysfs_unregistration(void)
 797 {
 798         sysfs_remove_group(ecryptfs_kobj, &attr_group);
 799         kobject_put(ecryptfs_kobj);
 800 }
 801
 802 static int __init ecryptfs_init(void)
 803 {
 804         int rc;
 805
 806         if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_CACHE_SIZE) {
 807                 rc = -EINVAL;
 808                 ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is "
 809                                 "larger than the host's page size, and so "
 810                                 "eCryptfs cannot run on this system. The "
 811                                 "default eCryptfs extent size is [%d] bytes; "
 812                                 "the page size is [%d] bytes.\n",
 813                                 ECRYPTFS_DEFAULT_EXTENT_SIZE, PAGE_CACHE_SIZE);
 814                 goto out;
 815         }
 816         rc = ecryptfs_init_kmem_caches();
 817         if (rc) {
 818                 printk(KERN_ERR
 819                        "Failed to allocate one or more kmem_cache objects\n");
 820                 goto out;
 821         }
 822         rc = register_filesystem(&ecryptfs_fs_type);
 823         if (rc) {
 824                 printk(KERN_ERR "Failed to register filesystem\n");
 825                 goto out_free_kmem_caches;
 826         }
 827         rc = do_sysfs_registration();
 828         if (rc) {
 829                 printk(KERN_ERR "sysfs registration failed\n");
 830                 goto out_unregister_filesystem;
 831         }
 832         rc = ecryptfs_init_kthread();
 833         if (rc) {
 834                 printk(KERN_ERR "%s: kthread initialization failed; "
 835                        "rc = [%d]\n", __func__, rc);
 836                 goto out_do_sysfs_unregistration;
 837         }
 838         rc = ecryptfs_init_messaging();
 839         if (rc) {
 840                 printk(KERN_ERR "Failure occured while attempting to "
 841                                 "initialize the communications channel to "
 842                                 "ecryptfsd\n");
 843                 goto out_destroy_kthread;
 844         }
 845         rc = ecryptfs_init_crypto();
 846         if (rc) {
 847                 printk(KERN_ERR "Failure whilst attempting to init crypto; "
 848                        "rc = [%d]\n", rc);
 849                 goto out_release_messaging;
 850         }
 851         if (ecryptfs_verbosity > 0)
 852                 printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values "
 853                         "will be written to the syslog!\n", ecryptfs_verbosity);
 854
 855         goto out;
 856 out_release_messaging:
 857         ecryptfs_release_messaging();
 858 out_destroy_kthread:
 859         ecryptfs_destroy_kthread();
 860 out_do_sysfs_unregistration:
 861         do_sysfs_unregistration();
 862 out_unregister_filesystem:
 863         unregister_filesystem(&ecryptfs_fs_type);
 864 out_free_kmem_caches:
 865         ecryptfs_free_kmem_caches();
 866 out:
 867         return rc;
 868 }
 869
 870 static void __exit ecryptfs_exit(void)
 871 {
 872         int rc;
 873
 874         rc = ecryptfs_destroy_crypto();
 875         if (rc)
 876                 printk(KERN_ERR "Failure whilst attempting to destroy crypto; "
 877                        "rc = [%d]\n", rc);
 878         ecryptfs_release_messaging();
 879         ecryptfs_destroy_kthread();
 880         do_sysfs_unregistration();
 881         unregister_filesystem(&ecryptfs_fs_type);
 882         ecryptfs_free_kmem_caches();
 883 }
 884
 885 MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>");
 886 MODULE_DESCRIPTION("eCryptfs");
 887
 888 MODULE_LICENSE("GPL");
 889
 890 module_init(ecryptfs_init)
 891 module_exit(ecryptfs_exit)