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/netlink.h>
  34 #include <linux/mount.h>
  35 #include <linux/pagemap.h>
  36 #include <linux/key.h>
  37 #include <linux/parser.h>
  38 #include <linux/fs_stack.h>
  39 #include "ecryptfs_kernel.h"
  40
  41 /**
  42  * Module parameter that defines the ecryptfs_verbosity level.
  43  */
  44 int ecryptfs_verbosity = 0;
  45
  46 module_param(ecryptfs_verbosity, int, 0);
  47 MODULE_PARM_DESC(ecryptfs_verbosity,
  48                  "Initial verbosity level (0 or 1; defaults to "
  49                  "0, which is Quiet)");
  50
  51 /**
  52  * Module parameter that defines the number of netlink message buffer
  53  * elements
  54  */
  55 unsigned int ecryptfs_message_buf_len = ECRYPTFS_DEFAULT_MSG_CTX_ELEMS;
  56
  57 module_param(ecryptfs_message_buf_len, uint, 0);
  58 MODULE_PARM_DESC(ecryptfs_message_buf_len,
  59                  "Number of message buffer elements");
  60
  61 /**
  62  * Module parameter that defines the maximum guaranteed amount of time to wait
  63  * for a response through netlink.  The actual sleep time will be, more than
  64  * likely, a small amount greater than this specified value, but only less if
  65  * the netlink message successfully arrives.
  66  */
  67 signed long ecryptfs_message_wait_timeout = ECRYPTFS_MAX_MSG_CTX_TTL / HZ;
  68
  69 module_param(ecryptfs_message_wait_timeout, long, 0);
  70 MODULE_PARM_DESC(ecryptfs_message_wait_timeout,
  71                  "Maximum number of seconds that an operation will "
  72                  "sleep while waiting for a message response from "
  73                  "userspace");
  74
  75 /**
  76  * Module parameter that is an estimate of the maximum number of users
  77  * that will be concurrently using eCryptfs. Set this to the right
  78  * value to balance performance and memory use.
  79  */
  80 unsigned int ecryptfs_number_of_users = ECRYPTFS_DEFAULT_NUM_USERS;
  81
  82 module_param(ecryptfs_number_of_users, uint, 0);
  83 MODULE_PARM_DESC(ecryptfs_number_of_users, "An estimate of the number of "
  84                  "concurrent users of eCryptfs");
  85
  86 unsigned int ecryptfs_transport = ECRYPTFS_DEFAULT_TRANSPORT;
  87
  88 void __ecryptfs_printk(const char *fmt, ...)
  89 {
  90         va_list args;
  91         va_start(args, fmt);
  92         if (fmt[1] == '7') { /* KERN_DEBUG */
  93                 if (ecryptfs_verbosity >= 1)
  94                         vprintk(fmt, args);
  95         } else
  96                 vprintk(fmt, args);
  97         va_end(args);
  98 }
  99
 100 /**
 101  * ecryptfs_init_persistent_file
 102  * @ecryptfs_dentry: Fully initialized eCryptfs dentry object, with
 103  *                   the lower dentry and the lower mount set
 104  *
 105  * eCryptfs only ever keeps a single open file for every lower
 106  * inode. All I/O operations to the lower inode occur through that
 107  * file. When the first eCryptfs dentry that interposes with the first
 108  * lower dentry for that inode is created, this function creates the
 109  * persistent file struct and associates it with the eCryptfs
 110  * inode. When the eCryptfs inode is destroyed, the file is closed.
 111  *
 112  * The persistent file will be opened with read/write permissions, if
 113  * possible. Otherwise, it is opened read-only.
 114  *
 115  * This function does nothing if a lower persistent file is already
 116  * associated with the eCryptfs inode.
 117  *
 118  * Returns zero on success; non-zero otherwise
 119  */
 120 int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry)
 121 {
 122         struct ecryptfs_inode_info *inode_info =
 123                 ecryptfs_inode_to_private(ecryptfs_dentry->d_inode);
 124         int rc = 0;
 125
 126         mutex_lock(&inode_info->lower_file_mutex);
 127         if (!inode_info->lower_file) {
 128                 struct dentry *lower_dentry;
 129                 struct vfsmount *lower_mnt =
 130                         ecryptfs_dentry_to_lower_mnt(ecryptfs_dentry);
 131
 132                 lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
 133                 /* Corresponding dput() and mntput() are done when the
 134                  * persistent file is fput() when the eCryptfs inode
 135                  * is destroyed. */
 136                 dget(lower_dentry);
 137                 mntget(lower_mnt);
 138                 inode_info->lower_file = dentry_open(lower_dentry,
 139                                                      lower_mnt,
 140                                                      (O_RDWR | O_LARGEFILE));
 141                 if (IS_ERR(inode_info->lower_file)) {
 142                         dget(lower_dentry);
 143                         mntget(lower_mnt);
 144                         inode_info->lower_file = dentry_open(lower_dentry,
 145                                                              lower_mnt,
 146                                                              (O_RDONLY
 147                                                               | O_LARGEFILE));
 148                 }
 149                 if (IS_ERR(inode_info->lower_file)) {
 150                         printk(KERN_ERR "Error opening lower persistent file "
 151                                "for lower_dentry [0x%p] and lower_mnt [0x%p]\n",
 152                                lower_dentry, lower_mnt);
 153                         rc = PTR_ERR(inode_info->lower_file);
 154                         inode_info->lower_file = NULL;
 155                 }
 156         }
 157         mutex_unlock(&inode_info->lower_file_mutex);
 158         return rc;
 159 }
 160
 161 /**
 162  * ecryptfs_interpose
 163  * @lower_dentry: Existing dentry in the lower filesystem
 164  * @dentry: ecryptfs' dentry
 165  * @sb: ecryptfs's super_block
 166  * @flag: If set to true, then d_add is called, else d_instantiate is called
 167  *
 168  * Interposes upper and lower dentries.
 169  *
 170  * Returns zero on success; non-zero otherwise
 171  */
 172 int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry,
 173                        struct super_block *sb, int flag)
 174 {
 175         struct inode *lower_inode;
 176         struct inode *inode;
 177         int rc = 0;
 178
 179         lower_inode = lower_dentry->d_inode;
 180         if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb)) {
 181                 rc = -EXDEV;
 182                 goto out;
 183         }
 184         if (!igrab(lower_inode)) {
 185                 rc = -ESTALE;
 186                 goto out;
 187         }
 188         inode = iget5_locked(sb, (unsigned long)lower_inode,
 189                              ecryptfs_inode_test, ecryptfs_inode_set,
 190                              lower_inode);
 191         if (!inode) {
 192                 rc = -EACCES;
 193                 iput(lower_inode);
 194                 goto out;
 195         }
 196         if (inode->i_state & I_NEW)
 197                 unlock_new_inode(inode);
 198         else
 199                 iput(lower_inode);
 200         if (S_ISLNK(lower_inode->i_mode))
 201                 inode->i_op = &ecryptfs_symlink_iops;
 202         else if (S_ISDIR(lower_inode->i_mode))
 203                 inode->i_op = &ecryptfs_dir_iops;
 204         if (S_ISDIR(lower_inode->i_mode))
 205                 inode->i_fop = &ecryptfs_dir_fops;
 206         if (special_file(lower_inode->i_mode))
 207                 init_special_inode(inode, lower_inode->i_mode,
 208                                    lower_inode->i_rdev);
 209         dentry->d_op = &ecryptfs_dops;
 210         if (flag)
 211                 d_add(dentry, inode);
 212         else
 213                 d_instantiate(dentry, inode);
 214         fsstack_copy_attr_all(inode, lower_inode, NULL);
 215         /* This size will be overwritten for real files w/ headers and
 216          * other metadata */
 217         fsstack_copy_inode_size(inode, lower_inode);
 218         rc = ecryptfs_init_persistent_file(dentry);
 219         if (rc) {
 220                 printk(KERN_ERR "%s: Error attempting to initialize the "
 221                        "persistent file for the dentry with name [%s]; "
 222                        "rc = [%d]\n", __FUNCTION__, dentry->d_name.name, rc);
 223                 goto out;
 224         }
 225 out:
 226         return rc;
 227 }
 228
 229 enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig, ecryptfs_opt_debug,
 230        ecryptfs_opt_ecryptfs_debug, ecryptfs_opt_cipher,
 231        ecryptfs_opt_ecryptfs_cipher, ecryptfs_opt_ecryptfs_key_bytes,
 232        ecryptfs_opt_passthrough, ecryptfs_opt_xattr_metadata,
 233        ecryptfs_opt_encrypted_view, ecryptfs_opt_err };
 234
 235 static match_table_t tokens = {
 236         {ecryptfs_opt_sig, "sig=%s"},
 237         {ecryptfs_opt_ecryptfs_sig, "ecryptfs_sig=%s"},
 238         {ecryptfs_opt_debug, "debug=%u"},
 239         {ecryptfs_opt_ecryptfs_debug, "ecryptfs_debug=%u"},
 240         {ecryptfs_opt_cipher, "cipher=%s"},
 241         {ecryptfs_opt_ecryptfs_cipher, "ecryptfs_cipher=%s"},
 242         {ecryptfs_opt_ecryptfs_key_bytes, "ecryptfs_key_bytes=%u"},
 243         {ecryptfs_opt_passthrough, "ecryptfs_passthrough"},
 244         {ecryptfs_opt_xattr_metadata, "ecryptfs_xattr_metadata"},
 245         {ecryptfs_opt_encrypted_view, "ecryptfs_encrypted_view"},
 246         {ecryptfs_opt_err, NULL}
 247 };
 248
 249 static int ecryptfs_init_global_auth_toks(
 250         struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
 251 {
 252         struct ecryptfs_global_auth_tok *global_auth_tok;
 253         int rc = 0;
 254
 255         list_for_each_entry(global_auth_tok,
 256                             &mount_crypt_stat->global_auth_tok_list,
 257                             mount_crypt_stat_list) {
 258                 rc = ecryptfs_keyring_auth_tok_for_sig(
 259                         &global_auth_tok->global_auth_tok_key,
 260                         &global_auth_tok->global_auth_tok,
 261                         global_auth_tok->sig);
 262                 if (rc) {
 263                         printk(KERN_ERR "Could not find valid key in user "
 264                                "session keyring for sig specified in mount "
 265                                "option: [%s]\n", global_auth_tok->sig);
 266                         global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID;
 267                         rc = 0;
 268                 } else
 269                         global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID;
 270         }
 271         return rc;
 272 }
 273
 274 static void ecryptfs_init_mount_crypt_stat(
 275         struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
 276 {
 277         memset((void *)mount_crypt_stat, 0,
 278                sizeof(struct ecryptfs_mount_crypt_stat));
 279         INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list);
 280         mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex);
 281         mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED;
 282 }
 283
 284 /**
 285  * ecryptfs_parse_options
 286  * @sb: The ecryptfs super block
 287  * @options: The options pased to the kernel
 288  *
 289  * Parse mount options:
 290  * debug=N         - ecryptfs_verbosity level for debug output
 291  * sig=XXX         - description(signature) of the key to use
 292  *
 293  * Returns the dentry object of the lower-level (lower/interposed)
 294  * directory; We want to mount our stackable file system on top of
 295  * that lower directory.
 296  *
 297  * The signature of the key to use must be the description of a key
 298  * already in the keyring. Mounting will fail if the key can not be
 299  * found.
 300  *
 301  * Returns zero on success; non-zero on error
 302  */
 303 static int ecryptfs_parse_options(struct super_block *sb, char *options)
 304 {
 305         char *p;
 306         int rc = 0;
 307         int sig_set = 0;
 308         int cipher_name_set = 0;
 309         int cipher_key_bytes;
 310         int cipher_key_bytes_set = 0;
 311         struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
 312                 &ecryptfs_superblock_to_private(sb)->mount_crypt_stat;
 313         substring_t args[MAX_OPT_ARGS];
 314         int token;
 315         char *sig_src;
 316         char *debug_src;
 317         char *cipher_name_dst;
 318         char *cipher_name_src;
 319         char *cipher_key_bytes_src;
 320         int cipher_name_len;
 321
 322         if (!options) {
 323                 rc = -EINVAL;
 324                 goto out;
 325         }
 326         ecryptfs_init_mount_crypt_stat(mount_crypt_stat);
 327         while ((p = strsep(&options, ",")) != NULL) {
 328                 if (!*p)
 329                         continue;
 330                 token = match_token(p, tokens, args);
 331                 switch (token) {
 332                 case ecryptfs_opt_sig:
 333                 case ecryptfs_opt_ecryptfs_sig:
 334                         sig_src = args[0].from;
 335                         rc = ecryptfs_add_global_auth_tok(mount_crypt_stat,
 336                                                           sig_src);
 337                         if (rc) {
 338                                 printk(KERN_ERR "Error attempting to register "
 339                                        "global sig; rc = [%d]\n", rc);
 340                                 goto out;
 341                         }
 342                         sig_set = 1;
 343                         break;
 344                 case ecryptfs_opt_debug:
 345                 case ecryptfs_opt_ecryptfs_debug:
 346                         debug_src = args[0].from;
 347                         ecryptfs_verbosity =
 348                                 (int)simple_strtol(debug_src, &debug_src,
 349                                                    0);
 350                         ecryptfs_printk(KERN_DEBUG,
 351                                         "Verbosity set to [%d]" "\n",
 352                                         ecryptfs_verbosity);
 353                         break;
 354                 case ecryptfs_opt_cipher:
 355                 case ecryptfs_opt_ecryptfs_cipher:
 356                         cipher_name_src = args[0].from;
 357                         cipher_name_dst =
 358                                 mount_crypt_stat->
 359                                 global_default_cipher_name;
 360                         strncpy(cipher_name_dst, cipher_name_src,
 361                                 ECRYPTFS_MAX_CIPHER_NAME_SIZE);
 362                         ecryptfs_printk(KERN_DEBUG,
 363                                         "The mount_crypt_stat "
 364                                         "global_default_cipher_name set to: "
 365                                         "[%s]\n", cipher_name_dst);
 366                         cipher_name_set = 1;
 367                         break;
 368                 case ecryptfs_opt_ecryptfs_key_bytes:
 369                         cipher_key_bytes_src = args[0].from;
 370                         cipher_key_bytes =
 371                                 (int)simple_strtol(cipher_key_bytes_src,
 372                                                    &cipher_key_bytes_src, 0);
 373                         mount_crypt_stat->global_default_cipher_key_size =
 374                                 cipher_key_bytes;
 375                         ecryptfs_printk(KERN_DEBUG,
 376                                         "The mount_crypt_stat "
 377                                         "global_default_cipher_key_size "
 378                                         "set to: [%d]\n", mount_crypt_stat->
 379                                         global_default_cipher_key_size);
 380                         cipher_key_bytes_set = 1;
 381                         break;
 382                 case ecryptfs_opt_passthrough:
 383                         mount_crypt_stat->flags |=
 384                                 ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED;
 385                         break;
 386                 case ecryptfs_opt_xattr_metadata:
 387                         mount_crypt_stat->flags |=
 388                                 ECRYPTFS_XATTR_METADATA_ENABLED;
 389                         break;
 390                 case ecryptfs_opt_encrypted_view:
 391                         mount_crypt_stat->flags |=
 392                                 ECRYPTFS_XATTR_METADATA_ENABLED;
 393                         mount_crypt_stat->flags |=
 394                                 ECRYPTFS_ENCRYPTED_VIEW_ENABLED;
 395                         break;
 396                 case ecryptfs_opt_err:
 397                 default:
 398                         ecryptfs_printk(KERN_WARNING,
 399                                         "eCryptfs: unrecognized option '%s'\n",
 400                                         p);
 401                 }
 402         }
 403         if (!sig_set) {
 404                 rc = -EINVAL;
 405                 ecryptfs_printk(KERN_ERR, "You must supply at least one valid "
 406                                 "auth tok signature as a mount "
 407                                 "parameter; see the eCryptfs README\n");
 408                 goto out;
 409         }
 410         if (!cipher_name_set) {
 411                 cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER);
 412                 if (unlikely(cipher_name_len
 413                              >= ECRYPTFS_MAX_CIPHER_NAME_SIZE)) {
 414                         rc = -EINVAL;
 415                         BUG();
 416                         goto out;
 417                 }
 418                 memcpy(mount_crypt_stat->global_default_cipher_name,
 419                        ECRYPTFS_DEFAULT_CIPHER, cipher_name_len);
 420                 mount_crypt_stat->global_default_cipher_name[cipher_name_len]
 421                     = '\0';
 422         }
 423         if (!cipher_key_bytes_set) {
 424                 mount_crypt_stat->global_default_cipher_key_size = 0;
 425         }
 426         rc = ecryptfs_add_new_key_tfm(
 427                 NULL, mount_crypt_stat->global_default_cipher_name,
 428                 mount_crypt_stat->global_default_cipher_key_size);
 429         if (rc) {
 430                 printk(KERN_ERR "Error attempting to initialize cipher with "
 431                        "name = [%s] and key size = [%td]; rc = [%d]\n",
 432                        mount_crypt_stat->global_default_cipher_name,
 433                        mount_crypt_stat->global_default_cipher_key_size, rc);
 434                 rc = -EINVAL;
 435                 goto out;
 436         }
 437         rc = ecryptfs_init_global_auth_toks(mount_crypt_stat);
 438         if (rc) {
 439                 printk(KERN_WARNING "One or more global auth toks could not "
 440                        "properly register; rc = [%d]\n", rc);
 441         }
 442         rc = 0;
 443 out:
 444         return rc;
 445 }
 446
 447 struct kmem_cache *ecryptfs_sb_info_cache;
 448
 449 /**
 450  * ecryptfs_fill_super
 451  * @sb: The ecryptfs super block
 452  * @raw_data: The options passed to mount
 453  * @silent: Not used but required by function prototype
 454  *
 455  * Sets up what we can of the sb, rest is done in ecryptfs_read_super
 456  *
 457  * Returns zero on success; non-zero otherwise
 458  */
 459 static int
 460 ecryptfs_fill_super(struct super_block *sb, void *raw_data, int silent)
 461 {
 462         int rc = 0;
 463
 464         /* Released in ecryptfs_put_super() */
 465         ecryptfs_set_superblock_private(sb,
 466                                         kmem_cache_zalloc(ecryptfs_sb_info_cache,
 467                                                          GFP_KERNEL));
 468         if (!ecryptfs_superblock_to_private(sb)) {
 469                 ecryptfs_printk(KERN_WARNING, "Out of memory\n");
 470                 rc = -ENOMEM;
 471                 goto out;
 472         }
 473         sb->s_op = &ecryptfs_sops;
 474         /* Released through deactivate_super(sb) from get_sb_nodev */
 475         sb->s_root = d_alloc(NULL, &(const struct qstr) {
 476                              .hash = 0,.name = "/",.len = 1});
 477         if (!sb->s_root) {
 478                 ecryptfs_printk(KERN_ERR, "d_alloc failed\n");
 479                 rc = -ENOMEM;
 480                 goto out;
 481         }
 482         sb->s_root->d_op = &ecryptfs_dops;
 483         sb->s_root->d_sb = sb;
 484         sb->s_root->d_parent = sb->s_root;
 485         /* Released in d_release when dput(sb->s_root) is called */
 486         /* through deactivate_super(sb) from get_sb_nodev() */
 487         ecryptfs_set_dentry_private(sb->s_root,
 488                                     kmem_cache_zalloc(ecryptfs_dentry_info_cache,
 489                                                      GFP_KERNEL));
 490         if (!ecryptfs_dentry_to_private(sb->s_root)) {
 491                 ecryptfs_printk(KERN_ERR,
 492                                 "dentry_info_cache alloc failed\n");
 493                 rc = -ENOMEM;
 494                 goto out;
 495         }
 496         rc = 0;
 497 out:
 498         /* Should be able to rely on deactivate_super called from
 499          * get_sb_nodev */
 500         return rc;
 501 }
 502
 503 /**
 504  * ecryptfs_read_super
 505  * @sb: The ecryptfs super block
 506  * @dev_name: The path to mount over
 507  *
 508  * Read the super block of the lower filesystem, and use
 509  * ecryptfs_interpose to create our initial inode and super block
 510  * struct.
 511  */
 512 static int ecryptfs_read_super(struct super_block *sb, const char *dev_name)
 513 {
 514         int rc;
 515         struct nameidata nd;
 516         struct dentry *lower_root;
 517         struct vfsmount *lower_mnt;
 518
 519         memset(&nd, 0, sizeof(struct nameidata));
 520         rc = path_lookup(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &nd);
 521         if (rc) {
 522                 ecryptfs_printk(KERN_WARNING, "path_lookup() failed\n");
 523                 goto out;
 524         }
 525         lower_root = nd.dentry;
 526         lower_mnt = nd.mnt;
 527         ecryptfs_set_superblock_lower(sb, lower_root->d_sb);
 528         sb->s_maxbytes = lower_root->d_sb->s_maxbytes;
 529         sb->s_blocksize = lower_root->d_sb->s_blocksize;
 530         ecryptfs_set_dentry_lower(sb->s_root, lower_root);
 531         ecryptfs_set_dentry_lower_mnt(sb->s_root, lower_mnt);
 532         rc = ecryptfs_interpose(lower_root, sb->s_root, sb, 0);
 533         if (rc)
 534                 goto out_free;
 535         rc = 0;
 536         goto out;
 537 out_free:
 538         path_release(&nd);
 539 out:
 540         return rc;
 541 }
 542
 543 /**
 544  * ecryptfs_get_sb
 545  * @fs_type
 546  * @flags
 547  * @dev_name: The path to mount over
 548  * @raw_data: The options passed into the kernel
 549  *
 550  * The whole ecryptfs_get_sb process is broken into 4 functions:
 551  * ecryptfs_parse_options(): handle options passed to ecryptfs, if any
 552  * ecryptfs_fill_super(): used by get_sb_nodev, fills out the super_block
 553  *                        with as much information as it can before needing
 554  *                        the lower filesystem.
 555  * ecryptfs_read_super(): this accesses the lower filesystem and uses
 556  *                        ecryptfs_interpolate to perform most of the linking
 557  * ecryptfs_interpolate(): links the lower filesystem into ecryptfs
 558  */
 559 static int ecryptfs_get_sb(struct file_system_type *fs_type, int flags,
 560                         const char *dev_name, void *raw_data,
 561                         struct vfsmount *mnt)
 562 {
 563         int rc;
 564         struct super_block *sb;
 565
 566         rc = get_sb_nodev(fs_type, flags, raw_data, ecryptfs_fill_super, mnt);
 567         if (rc < 0) {
 568                 printk(KERN_ERR "Getting sb failed; rc = [%d]\n", rc);
 569                 goto out;
 570         }
 571         sb = mnt->mnt_sb;
 572         rc = ecryptfs_parse_options(sb, raw_data);
 573         if (rc) {
 574                 printk(KERN_ERR "Error parsing options; rc = [%d]\n", rc);
 575                 goto out_abort;
 576         }
 577         rc = ecryptfs_read_super(sb, dev_name);
 578         if (rc) {
 579                 printk(KERN_ERR "Reading sb failed; rc = [%d]\n", rc);
 580                 goto out_abort;
 581         }
 582         goto out;
 583 out_abort:
 584         dput(sb->s_root);
 585         up_write(&sb->s_umount);
 586         deactivate_super(sb);
 587 out:
 588         return rc;
 589 }
 590
 591 /**
 592  * ecryptfs_kill_block_super
 593  * @sb: The ecryptfs super block
 594  *
 595  * Used to bring the superblock down and free the private data.
 596  * Private data is free'd in ecryptfs_put_super()
 597  */
 598 static void ecryptfs_kill_block_super(struct super_block *sb)
 599 {
 600         generic_shutdown_super(sb);
 601 }
 602
 603 static struct file_system_type ecryptfs_fs_type = {
 604         .owner = THIS_MODULE,
 605         .name = "ecryptfs",
 606         .get_sb = ecryptfs_get_sb,
 607         .kill_sb = ecryptfs_kill_block_super,
 608         .fs_flags = 0
 609 };
 610
 611 /**
 612  * inode_info_init_once
 613  *
 614  * Initializes the ecryptfs_inode_info_cache when it is created
 615  */
 616 static void
 617 inode_info_init_once(struct kmem_cache *cachep, void *vptr)
 618 {
 619         struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr;
 620
 621         inode_init_once(&ei->vfs_inode);
 622 }
 623
 624 static struct ecryptfs_cache_info {
 625         struct kmem_cache **cache;
 626         const char *name;
 627         size_t size;
 628         void (*ctor)(struct kmem_cache *cache, void *obj);
 629 } ecryptfs_cache_infos[] = {
 630         {
 631                 .cache = &ecryptfs_auth_tok_list_item_cache,
 632                 .name = "ecryptfs_auth_tok_list_item",
 633                 .size = sizeof(struct ecryptfs_auth_tok_list_item),
 634         },
 635         {
 636                 .cache = &ecryptfs_file_info_cache,
 637                 .name = "ecryptfs_file_cache",
 638                 .size = sizeof(struct ecryptfs_file_info),
 639         },
 640         {
 641                 .cache = &ecryptfs_dentry_info_cache,
 642                 .name = "ecryptfs_dentry_info_cache",
 643                 .size = sizeof(struct ecryptfs_dentry_info),
 644         },
 645         {
 646                 .cache = &ecryptfs_inode_info_cache,
 647                 .name = "ecryptfs_inode_cache",
 648                 .size = sizeof(struct ecryptfs_inode_info),
 649                 .ctor = inode_info_init_once,
 650         },
 651         {
 652                 .cache = &ecryptfs_sb_info_cache,
 653                 .name = "ecryptfs_sb_cache",
 654                 .size = sizeof(struct ecryptfs_sb_info),
 655         },
 656         {
 657                 .cache = &ecryptfs_header_cache_0,
 658                 .name = "ecryptfs_headers_0",
 659                 .size = PAGE_CACHE_SIZE,
 660         },
 661         {
 662                 .cache = &ecryptfs_header_cache_1,
 663                 .name = "ecryptfs_headers_1",
 664                 .size = PAGE_CACHE_SIZE,
 665         },
 666         {
 667                 .cache = &ecryptfs_header_cache_2,
 668                 .name = "ecryptfs_headers_2",
 669                 .size = PAGE_CACHE_SIZE,
 670         },
 671         {
 672                 .cache = &ecryptfs_xattr_cache,
 673                 .name = "ecryptfs_xattr_cache",
 674                 .size = PAGE_CACHE_SIZE,
 675         },
 676         {
 677                 .cache = &ecryptfs_key_record_cache,
 678                 .name = "ecryptfs_key_record_cache",
 679                 .size = sizeof(struct ecryptfs_key_record),
 680         },
 681         {
 682                 .cache = &ecryptfs_key_sig_cache,
 683                 .name = "ecryptfs_key_sig_cache",
 684                 .size = sizeof(struct ecryptfs_key_sig),
 685         },
 686         {
 687                 .cache = &ecryptfs_global_auth_tok_cache,
 688                 .name = "ecryptfs_global_auth_tok_cache",
 689                 .size = sizeof(struct ecryptfs_global_auth_tok),
 690         },
 691         {
 692                 .cache = &ecryptfs_key_tfm_cache,
 693                 .name = "ecryptfs_key_tfm_cache",
 694                 .size = sizeof(struct ecryptfs_key_tfm),
 695         },
 696 };
 697
 698 static void ecryptfs_free_kmem_caches(void)
 699 {
 700         int i;
 701
 702         for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
 703                 struct ecryptfs_cache_info *info;
 704
 705                 info = &ecryptfs_cache_infos[i];
 706                 if (*(info->cache))
 707                         kmem_cache_destroy(*(info->cache));
 708         }
 709 }
 710
 711 /**
 712  * ecryptfs_init_kmem_caches
 713  *
 714  * Returns zero on success; non-zero otherwise
 715  */
 716 static int ecryptfs_init_kmem_caches(void)
 717 {
 718         int i;
 719
 720         for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
 721                 struct ecryptfs_cache_info *info;
 722
 723                 info = &ecryptfs_cache_infos[i];
 724                 *(info->cache) = kmem_cache_create(info->name, info->size,
 725                                 0, SLAB_HWCACHE_ALIGN, info->ctor);
 726                 if (!*(info->cache)) {
 727                         ecryptfs_free_kmem_caches();
 728                         ecryptfs_printk(KERN_WARNING, "%s: "
 729                                         "kmem_cache_create failed\n",
 730                                         info->name);
 731                         return -ENOMEM;
 732                 }
 733         }
 734         return 0;
 735 }
 736
 737 static struct kobject *ecryptfs_kobj;
 738
 739 static ssize_t version_show(struct kobject *kobj,
 740                             struct kobj_attribute *attr, char *buff)
 741 {
 742         return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK);
 743 }
 744
 745 static struct kobj_attribute version_attr = __ATTR_RO(version);
 746
 747 static struct attribute *attributes[] = {
 748         &version_attr.attr,
 749         NULL,
 750 };
 751
 752 static struct attribute_group attr_group = {
 753         .attrs = attributes,
 754 };
 755
 756 static int do_sysfs_registration(void)
 757 {
 758         int rc;
 759
 760         ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj);
 761         if (!ecryptfs_kobj) {
 762                 printk(KERN_ERR "Unable to create ecryptfs kset\n");
 763                 rc = -ENOMEM;
 764                 goto out;
 765         }
 766         rc = sysfs_create_group(ecryptfs_kobj, &attr_group);
 767         if (rc) {
 768                 printk(KERN_ERR
 769                        "Unable to create ecryptfs version attributes\n");
 770                 kobject_put(ecryptfs_kobj);
 771         }
 772 out:
 773         return rc;
 774 }
 775
 776 static void do_sysfs_unregistration(void)
 777 {
 778         sysfs_remove_group(ecryptfs_kobj, &attr_group);
 779         kobject_put(ecryptfs_kobj);
 780 }
 781
 782 static int __init ecryptfs_init(void)
 783 {
 784         int rc;
 785
 786         if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_CACHE_SIZE) {
 787                 rc = -EINVAL;
 788                 ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is "
 789                                 "larger than the host's page size, and so "
 790                                 "eCryptfs cannot run on this system. The "
 791                                 "default eCryptfs extent size is [%d] bytes; "
 792                                 "the page size is [%d] bytes.\n",
 793                                 ECRYPTFS_DEFAULT_EXTENT_SIZE, PAGE_CACHE_SIZE);
 794                 goto out;
 795         }
 796         rc = ecryptfs_init_kmem_caches();
 797         if (rc) {
 798                 printk(KERN_ERR
 799                        "Failed to allocate one or more kmem_cache objects\n");
 800                 goto out;
 801         }
 802         rc = register_filesystem(&ecryptfs_fs_type);
 803         if (rc) {
 804                 printk(KERN_ERR "Failed to register filesystem\n");
 805                 goto out_free_kmem_caches;
 806         }
 807         rc = do_sysfs_registration();
 808         if (rc) {
 809                 printk(KERN_ERR "sysfs registration failed\n");
 810                 goto out_unregister_filesystem;
 811         }
 812         rc = ecryptfs_init_messaging(ecryptfs_transport);
 813         if (rc) {
 814                 ecryptfs_printk(KERN_ERR, "Failure occured while attempting to "
 815                                 "initialize the eCryptfs netlink socket\n");
 816                 goto out_do_sysfs_unregistration;
 817         }
 818         rc = ecryptfs_init_crypto();
 819         if (rc) {
 820                 printk(KERN_ERR "Failure whilst attempting to init crypto; "
 821                        "rc = [%d]\n", rc);
 822                 goto out_release_messaging;
 823         }
 824         goto out;
 825 out_release_messaging:
 826         ecryptfs_release_messaging(ecryptfs_transport);
 827 out_do_sysfs_unregistration:
 828         do_sysfs_unregistration();
 829 out_unregister_filesystem:
 830         unregister_filesystem(&ecryptfs_fs_type);
 831 out_free_kmem_caches:
 832         ecryptfs_free_kmem_caches();
 833 out:
 834         return rc;
 835 }
 836
 837 static void __exit ecryptfs_exit(void)
 838 {
 839         int rc;
 840
 841         rc = ecryptfs_destroy_crypto();
 842         if (rc)
 843                 printk(KERN_ERR "Failure whilst attempting to destroy crypto; "
 844                        "rc = [%d]\n", rc);
 845         ecryptfs_release_messaging(ecryptfs_transport);
 846         do_sysfs_unregistration();
 847         unregister_filesystem(&ecryptfs_fs_type);
 848         ecryptfs_free_kmem_caches();
 849 }
 850
 851 MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>");
 852 MODULE_DESCRIPTION("eCryptfs");
 853
 854 MODULE_LICENSE("GPL");
 855
 856 module_init(ecryptfs_init)
 857 module_exit(ecryptfs_exit)