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 static 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", __func__, 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,
 230        ecryptfs_opt_cipher, ecryptfs_opt_ecryptfs_cipher,
 231        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_cipher, "cipher=%s"},
 239         {ecryptfs_opt_ecryptfs_cipher, "ecryptfs_cipher=%s"},
 240         {ecryptfs_opt_ecryptfs_key_bytes, "ecryptfs_key_bytes=%u"},
 241         {ecryptfs_opt_passthrough, "ecryptfs_passthrough"},
 242         {ecryptfs_opt_xattr_metadata, "ecryptfs_xattr_metadata"},
 243         {ecryptfs_opt_encrypted_view, "ecryptfs_encrypted_view"},
 244         {ecryptfs_opt_err, NULL}
 245 };
 246
 247 static int ecryptfs_init_global_auth_toks(
 248         struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
 249 {
 250         struct ecryptfs_global_auth_tok *global_auth_tok;
 251         int rc = 0;
 252
 253         list_for_each_entry(global_auth_tok,
 254                             &mount_crypt_stat->global_auth_tok_list,
 255                             mount_crypt_stat_list) {
 256                 rc = ecryptfs_keyring_auth_tok_for_sig(
 257                         &global_auth_tok->global_auth_tok_key,
 258                         &global_auth_tok->global_auth_tok,
 259                         global_auth_tok->sig);
 260                 if (rc) {
 261                         printk(KERN_ERR "Could not find valid key in user "
 262                                "session keyring for sig specified in mount "
 263                                "option: [%s]\n", global_auth_tok->sig);
 264                         global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID;
 265                         rc = 0;
 266                 } else
 267                         global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID;
 268         }
 269         return rc;
 270 }
 271
 272 static void ecryptfs_init_mount_crypt_stat(
 273         struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
 274 {
 275         memset((void *)mount_crypt_stat, 0,
 276                sizeof(struct ecryptfs_mount_crypt_stat));
 277         INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list);
 278         mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex);
 279         mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED;
 280 }
 281
 282 /**
 283  * ecryptfs_parse_options
 284  * @sb: The ecryptfs super block
 285  * @options: The options pased to the kernel
 286  *
 287  * Parse mount options:
 288  * debug=N         - ecryptfs_verbosity level for debug output
 289  * sig=XXX         - description(signature) of the key to use
 290  *
 291  * Returns the dentry object of the lower-level (lower/interposed)
 292  * directory; We want to mount our stackable file system on top of
 293  * that lower directory.
 294  *
 295  * The signature of the key to use must be the description of a key
 296  * already in the keyring. Mounting will fail if the key can not be
 297  * found.
 298  *
 299  * Returns zero on success; non-zero on error
 300  */
 301 static int ecryptfs_parse_options(struct super_block *sb, char *options)
 302 {
 303         char *p;
 304         int rc = 0;
 305         int sig_set = 0;
 306         int cipher_name_set = 0;
 307         int cipher_key_bytes;
 308         int cipher_key_bytes_set = 0;
 309         struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
 310                 &ecryptfs_superblock_to_private(sb)->mount_crypt_stat;
 311         substring_t args[MAX_OPT_ARGS];
 312         int token;
 313         char *sig_src;
 314         char *cipher_name_dst;
 315         char *cipher_name_src;
 316         char *cipher_key_bytes_src;
 317         int cipher_name_len;
 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);
 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                         ecryptfs_printk(KERN_DEBUG,
 350                                         "The mount_crypt_stat "
 351                                         "global_default_cipher_name set to: "
 352                                         "[%s]\n", cipher_name_dst);
 353                         cipher_name_set = 1;
 354                         break;
 355                 case ecryptfs_opt_ecryptfs_key_bytes:
 356                         cipher_key_bytes_src = args[0].from;
 357                         cipher_key_bytes =
 358                                 (int)simple_strtol(cipher_key_bytes_src,
 359                                                    &cipher_key_bytes_src, 0);
 360                         mount_crypt_stat->global_default_cipher_key_size =
 361                                 cipher_key_bytes;
 362                         ecryptfs_printk(KERN_DEBUG,
 363                                         "The mount_crypt_stat "
 364                                         "global_default_cipher_key_size "
 365                                         "set to: [%d]\n", mount_crypt_stat->
 366                                         global_default_cipher_key_size);
 367                         cipher_key_bytes_set = 1;
 368                         break;
 369                 case ecryptfs_opt_passthrough:
 370                         mount_crypt_stat->flags |=
 371                                 ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED;
 372                         break;
 373                 case ecryptfs_opt_xattr_metadata:
 374                         mount_crypt_stat->flags |=
 375                                 ECRYPTFS_XATTR_METADATA_ENABLED;
 376                         break;
 377                 case ecryptfs_opt_encrypted_view:
 378                         mount_crypt_stat->flags |=
 379                                 ECRYPTFS_XATTR_METADATA_ENABLED;
 380                         mount_crypt_stat->flags |=
 381                                 ECRYPTFS_ENCRYPTED_VIEW_ENABLED;
 382                         break;
 383                 case ecryptfs_opt_err:
 384                 default:
 385                         ecryptfs_printk(KERN_WARNING,
 386                                         "eCryptfs: unrecognized option '%s'\n",
 387                                         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                 cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER);
 399                 if (unlikely(cipher_name_len
 400                              >= ECRYPTFS_MAX_CIPHER_NAME_SIZE)) {
 401                         rc = -EINVAL;
 402                         BUG();
 403                         goto out;
 404                 }
 405                 memcpy(mount_crypt_stat->global_default_cipher_name,
 406                        ECRYPTFS_DEFAULT_CIPHER, cipher_name_len);
 407                 mount_crypt_stat->global_default_cipher_name[cipher_name_len]
 408                     = '\0';
 409         }
 410         if (!cipher_key_bytes_set) {
 411                 mount_crypt_stat->global_default_cipher_key_size = 0;
 412         }
 413         mutex_lock(&key_tfm_list_mutex);
 414         if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name,
 415                                  NULL))
 416                 rc = ecryptfs_add_new_key_tfm(
 417                         NULL, mount_crypt_stat->global_default_cipher_name,
 418                         mount_crypt_stat->global_default_cipher_key_size);
 419         mutex_unlock(&key_tfm_list_mutex);
 420         if (rc) {
 421                 printk(KERN_ERR "Error attempting to initialize cipher with "
 422                        "name = [%s] and key size = [%td]; rc = [%d]\n",
 423                        mount_crypt_stat->global_default_cipher_name,
 424                        mount_crypt_stat->global_default_cipher_key_size, rc);
 425                 rc = -EINVAL;
 426                 goto out;
 427         }
 428         rc = ecryptfs_init_global_auth_toks(mount_crypt_stat);
 429         if (rc) {
 430                 printk(KERN_WARNING "One or more global auth toks could not "
 431                        "properly register; rc = [%d]\n", rc);
 432         }
 433         rc = 0;
 434 out:
 435         return rc;
 436 }
 437
 438 struct kmem_cache *ecryptfs_sb_info_cache;
 439
 440 /**
 441  * ecryptfs_fill_super
 442  * @sb: The ecryptfs super block
 443  * @raw_data: The options passed to mount
 444  * @silent: Not used but required by function prototype
 445  *
 446  * Sets up what we can of the sb, rest is done in ecryptfs_read_super
 447  *
 448  * Returns zero on success; non-zero otherwise
 449  */
 450 static int
 451 ecryptfs_fill_super(struct super_block *sb, void *raw_data, int silent)
 452 {
 453         int rc = 0;
 454
 455         /* Released in ecryptfs_put_super() */
 456         ecryptfs_set_superblock_private(sb,
 457                                         kmem_cache_zalloc(ecryptfs_sb_info_cache,
 458                                                          GFP_KERNEL));
 459         if (!ecryptfs_superblock_to_private(sb)) {
 460                 ecryptfs_printk(KERN_WARNING, "Out of memory\n");
 461                 rc = -ENOMEM;
 462                 goto out;
 463         }
 464         sb->s_op = &ecryptfs_sops;
 465         /* Released through deactivate_super(sb) from get_sb_nodev */
 466         sb->s_root = d_alloc(NULL, &(const struct qstr) {
 467                              .hash = 0,.name = "/",.len = 1});
 468         if (!sb->s_root) {
 469                 ecryptfs_printk(KERN_ERR, "d_alloc failed\n");
 470                 rc = -ENOMEM;
 471                 goto out;
 472         }
 473         sb->s_root->d_op = &ecryptfs_dops;
 474         sb->s_root->d_sb = sb;
 475         sb->s_root->d_parent = sb->s_root;
 476         /* Released in d_release when dput(sb->s_root) is called */
 477         /* through deactivate_super(sb) from get_sb_nodev() */
 478         ecryptfs_set_dentry_private(sb->s_root,
 479                                     kmem_cache_zalloc(ecryptfs_dentry_info_cache,
 480                                                      GFP_KERNEL));
 481         if (!ecryptfs_dentry_to_private(sb->s_root)) {
 482                 ecryptfs_printk(KERN_ERR,
 483                                 "dentry_info_cache alloc failed\n");
 484                 rc = -ENOMEM;
 485                 goto out;
 486         }
 487         rc = 0;
 488 out:
 489         /* Should be able to rely on deactivate_super called from
 490          * get_sb_nodev */
 491         return rc;
 492 }
 493
 494 /**
 495  * ecryptfs_read_super
 496  * @sb: The ecryptfs super block
 497  * @dev_name: The path to mount over
 498  *
 499  * Read the super block of the lower filesystem, and use
 500  * ecryptfs_interpose to create our initial inode and super block
 501  * struct.
 502  */
 503 static int ecryptfs_read_super(struct super_block *sb, const char *dev_name)
 504 {
 505         int rc;
 506         struct nameidata nd;
 507         struct dentry *lower_root;
 508         struct vfsmount *lower_mnt;
 509
 510         memset(&nd, 0, sizeof(struct nameidata));
 511         rc = path_lookup(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &nd);
 512         if (rc) {
 513                 ecryptfs_printk(KERN_WARNING, "path_lookup() failed\n");
 514                 goto out;
 515         }
 516         lower_root = nd.path.dentry;
 517         lower_mnt = nd.path.mnt;
 518         ecryptfs_set_superblock_lower(sb, lower_root->d_sb);
 519         sb->s_maxbytes = lower_root->d_sb->s_maxbytes;
 520         sb->s_blocksize = lower_root->d_sb->s_blocksize;
 521         ecryptfs_set_dentry_lower(sb->s_root, lower_root);
 522         ecryptfs_set_dentry_lower_mnt(sb->s_root, lower_mnt);
 523         rc = ecryptfs_interpose(lower_root, sb->s_root, sb, 0);
 524         if (rc)
 525                 goto out_free;
 526         rc = 0;
 527         goto out;
 528 out_free:
 529         path_put(&nd.path);
 530 out:
 531         return rc;
 532 }
 533
 534 /**
 535  * ecryptfs_get_sb
 536  * @fs_type
 537  * @flags
 538  * @dev_name: The path to mount over
 539  * @raw_data: The options passed into the kernel
 540  *
 541  * The whole ecryptfs_get_sb process is broken into 4 functions:
 542  * ecryptfs_parse_options(): handle options passed to ecryptfs, if any
 543  * ecryptfs_fill_super(): used by get_sb_nodev, fills out the super_block
 544  *                        with as much information as it can before needing
 545  *                        the lower filesystem.
 546  * ecryptfs_read_super(): this accesses the lower filesystem and uses
 547  *                        ecryptfs_interpolate to perform most of the linking
 548  * ecryptfs_interpolate(): links the lower filesystem into ecryptfs
 549  */
 550 static int ecryptfs_get_sb(struct file_system_type *fs_type, int flags,
 551                         const char *dev_name, void *raw_data,
 552                         struct vfsmount *mnt)
 553 {
 554         int rc;
 555         struct super_block *sb;
 556
 557         rc = get_sb_nodev(fs_type, flags, raw_data, ecryptfs_fill_super, mnt);
 558         if (rc < 0) {
 559                 printk(KERN_ERR "Getting sb failed; rc = [%d]\n", rc);
 560                 goto out;
 561         }
 562         sb = mnt->mnt_sb;
 563         rc = ecryptfs_parse_options(sb, raw_data);
 564         if (rc) {
 565                 printk(KERN_ERR "Error parsing options; rc = [%d]\n", rc);
 566                 goto out_abort;
 567         }
 568         rc = ecryptfs_read_super(sb, dev_name);
 569         if (rc) {
 570                 printk(KERN_ERR "Reading sb failed; rc = [%d]\n", rc);
 571                 goto out_abort;
 572         }
 573         goto out;
 574 out_abort:
 575         dput(sb->s_root);
 576         up_write(&sb->s_umount);
 577         deactivate_super(sb);
 578 out:
 579         return rc;
 580 }
 581
 582 /**
 583  * ecryptfs_kill_block_super
 584  * @sb: The ecryptfs super block
 585  *
 586  * Used to bring the superblock down and free the private data.
 587  * Private data is free'd in ecryptfs_put_super()
 588  */
 589 static void ecryptfs_kill_block_super(struct super_block *sb)
 590 {
 591         generic_shutdown_super(sb);
 592 }
 593
 594 static struct file_system_type ecryptfs_fs_type = {
 595         .owner = THIS_MODULE,
 596         .name = "ecryptfs",
 597         .get_sb = ecryptfs_get_sb,
 598         .kill_sb = ecryptfs_kill_block_super,
 599         .fs_flags = 0
 600 };
 601
 602 /**
 603  * inode_info_init_once
 604  *
 605  * Initializes the ecryptfs_inode_info_cache when it is created
 606  */
 607 static void
 608 inode_info_init_once(struct kmem_cache *cachep, void *vptr)
 609 {
 610         struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr;
 611
 612         inode_init_once(&ei->vfs_inode);
 613 }
 614
 615 static struct ecryptfs_cache_info {
 616         struct kmem_cache **cache;
 617         const char *name;
 618         size_t size;
 619         void (*ctor)(struct kmem_cache *cache, void *obj);
 620 } ecryptfs_cache_infos[] = {
 621         {
 622                 .cache = &ecryptfs_auth_tok_list_item_cache,
 623                 .name = "ecryptfs_auth_tok_list_item",
 624                 .size = sizeof(struct ecryptfs_auth_tok_list_item),
 625         },
 626         {
 627                 .cache = &ecryptfs_file_info_cache,
 628                 .name = "ecryptfs_file_cache",
 629                 .size = sizeof(struct ecryptfs_file_info),
 630         },
 631         {
 632                 .cache = &ecryptfs_dentry_info_cache,
 633                 .name = "ecryptfs_dentry_info_cache",
 634                 .size = sizeof(struct ecryptfs_dentry_info),
 635         },
 636         {
 637                 .cache = &ecryptfs_inode_info_cache,
 638                 .name = "ecryptfs_inode_cache",
 639                 .size = sizeof(struct ecryptfs_inode_info),
 640                 .ctor = inode_info_init_once,
 641         },
 642         {
 643                 .cache = &ecryptfs_sb_info_cache,
 644                 .name = "ecryptfs_sb_cache",
 645                 .size = sizeof(struct ecryptfs_sb_info),
 646         },
 647         {
 648                 .cache = &ecryptfs_header_cache_1,
 649                 .name = "ecryptfs_headers_1",
 650                 .size = PAGE_CACHE_SIZE,
 651         },
 652         {
 653                 .cache = &ecryptfs_header_cache_2,
 654                 .name = "ecryptfs_headers_2",
 655                 .size = PAGE_CACHE_SIZE,
 656         },
 657         {
 658                 .cache = &ecryptfs_xattr_cache,
 659                 .name = "ecryptfs_xattr_cache",
 660                 .size = PAGE_CACHE_SIZE,
 661         },
 662         {
 663                 .cache = &ecryptfs_key_record_cache,
 664                 .name = "ecryptfs_key_record_cache",
 665                 .size = sizeof(struct ecryptfs_key_record),
 666         },
 667         {
 668                 .cache = &ecryptfs_key_sig_cache,
 669                 .name = "ecryptfs_key_sig_cache",
 670                 .size = sizeof(struct ecryptfs_key_sig),
 671         },
 672         {
 673                 .cache = &ecryptfs_global_auth_tok_cache,
 674                 .name = "ecryptfs_global_auth_tok_cache",
 675                 .size = sizeof(struct ecryptfs_global_auth_tok),
 676         },
 677         {
 678                 .cache = &ecryptfs_key_tfm_cache,
 679                 .name = "ecryptfs_key_tfm_cache",
 680                 .size = sizeof(struct ecryptfs_key_tfm),
 681         },
 682 };
 683
 684 static void ecryptfs_free_kmem_caches(void)
 685 {
 686         int i;
 687
 688         for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
 689                 struct ecryptfs_cache_info *info;
 690
 691                 info = &ecryptfs_cache_infos[i];
 692                 if (*(info->cache))
 693                         kmem_cache_destroy(*(info->cache));
 694         }
 695 }
 696
 697 /**
 698  * ecryptfs_init_kmem_caches
 699  *
 700  * Returns zero on success; non-zero otherwise
 701  */
 702 static int ecryptfs_init_kmem_caches(void)
 703 {
 704         int i;
 705
 706         for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
 707                 struct ecryptfs_cache_info *info;
 708
 709                 info = &ecryptfs_cache_infos[i];
 710                 *(info->cache) = kmem_cache_create(info->name, info->size,
 711                                 0, SLAB_HWCACHE_ALIGN, info->ctor);
 712                 if (!*(info->cache)) {
 713                         ecryptfs_free_kmem_caches();
 714                         ecryptfs_printk(KERN_WARNING, "%s: "
 715                                         "kmem_cache_create failed\n",
 716                                         info->name);
 717                         return -ENOMEM;
 718                 }
 719         }
 720         return 0;
 721 }
 722
 723 static struct kobject *ecryptfs_kobj;
 724
 725 static ssize_t version_show(struct kobject *kobj,
 726                             struct kobj_attribute *attr, char *buff)
 727 {
 728         return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK);
 729 }
 730
 731 static struct kobj_attribute version_attr = __ATTR_RO(version);
 732
 733 static struct attribute *attributes[] = {
 734         &version_attr.attr,
 735         NULL,
 736 };
 737
 738 static struct attribute_group attr_group = {
 739         .attrs = attributes,
 740 };
 741
 742 static int do_sysfs_registration(void)
 743 {
 744         int rc;
 745
 746         ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj);
 747         if (!ecryptfs_kobj) {
 748                 printk(KERN_ERR "Unable to create ecryptfs kset\n");
 749                 rc = -ENOMEM;
 750                 goto out;
 751         }
 752         rc = sysfs_create_group(ecryptfs_kobj, &attr_group);
 753         if (rc) {
 754                 printk(KERN_ERR
 755                        "Unable to create ecryptfs version attributes\n");
 756                 kobject_put(ecryptfs_kobj);
 757         }
 758 out:
 759         return rc;
 760 }
 761
 762 static void do_sysfs_unregistration(void)
 763 {
 764         sysfs_remove_group(ecryptfs_kobj, &attr_group);
 765         kobject_put(ecryptfs_kobj);
 766 }
 767
 768 static int __init ecryptfs_init(void)
 769 {
 770         int rc;
 771
 772         if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_CACHE_SIZE) {
 773                 rc = -EINVAL;
 774                 ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is "
 775                                 "larger than the host's page size, and so "
 776                                 "eCryptfs cannot run on this system. The "
 777                                 "default eCryptfs extent size is [%d] bytes; "
 778                                 "the page size is [%d] bytes.\n",
 779                                 ECRYPTFS_DEFAULT_EXTENT_SIZE, PAGE_CACHE_SIZE);
 780                 goto out;
 781         }
 782         rc = ecryptfs_init_kmem_caches();
 783         if (rc) {
 784                 printk(KERN_ERR
 785                        "Failed to allocate one or more kmem_cache objects\n");
 786                 goto out;
 787         }
 788         rc = register_filesystem(&ecryptfs_fs_type);
 789         if (rc) {
 790                 printk(KERN_ERR "Failed to register filesystem\n");
 791                 goto out_free_kmem_caches;
 792         }
 793         rc = do_sysfs_registration();
 794         if (rc) {
 795                 printk(KERN_ERR "sysfs registration failed\n");
 796                 goto out_unregister_filesystem;
 797         }
 798         rc = ecryptfs_init_messaging(ecryptfs_transport);
 799         if (rc) {
 800                 ecryptfs_printk(KERN_ERR, "Failure occured while attempting to "
 801                                 "initialize the eCryptfs netlink socket\n");
 802                 goto out_do_sysfs_unregistration;
 803         }
 804         rc = ecryptfs_init_crypto();
 805         if (rc) {
 806                 printk(KERN_ERR "Failure whilst attempting to init crypto; "
 807                        "rc = [%d]\n", rc);
 808                 goto out_release_messaging;
 809         }
 810         if (ecryptfs_verbosity > 0)
 811                 printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values "
 812                         "will be written to the syslog!\n", ecryptfs_verbosity);
 813
 814         goto out;
 815 out_release_messaging:
 816         ecryptfs_release_messaging(ecryptfs_transport);
 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(ecryptfs_transport);
 836         do_sysfs_unregistration();
 837         unregister_filesystem(&ecryptfs_fs_type);
 838         ecryptfs_free_kmem_caches();
 839 }
 840
 841 MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>");
 842 MODULE_DESCRIPTION("eCryptfs");
 843
 844 MODULE_LICENSE("GPL");
 845
 846 module_init(ecryptfs_init)
 847 module_exit(ecryptfs_exit)