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 "ecryptfs_kernel.h"
  39
  40 /**
  41  * Module parameter that defines the ecryptfs_verbosity level.
  42  */
  43 int ecryptfs_verbosity = 0;
  44
  45 module_param(ecryptfs_verbosity, int, 0);
  46 MODULE_PARM_DESC(ecryptfs_verbosity,
  47                  "Initial verbosity level (0 or 1; defaults to "
  48                  "0, which is Quiet)");
  49
  50 /**
  51  * Module parameter that defines the number of message buffer elements
  52  */
  53 unsigned int ecryptfs_message_buf_len = ECRYPTFS_DEFAULT_MSG_CTX_ELEMS;
  54
  55 module_param(ecryptfs_message_buf_len, uint, 0);
  56 MODULE_PARM_DESC(ecryptfs_message_buf_len,
  57                  "Number of message buffer elements");
  58
  59 /**
  60  * Module parameter that defines the maximum guaranteed amount of time to wait
  61  * for a response from ecryptfsd.  The actual sleep time will be, more than
  62  * likely, a small amount greater than this specified value, but only less if
  63  * the message successfully arrives.
  64  */
  65 signed long ecryptfs_message_wait_timeout = ECRYPTFS_MAX_MSG_CTX_TTL / HZ;
  66
  67 module_param(ecryptfs_message_wait_timeout, long, 0);
  68 MODULE_PARM_DESC(ecryptfs_message_wait_timeout,
  69                  "Maximum number of seconds that an operation will "
  70                  "sleep while waiting for a message response from "
  71                  "userspace");
  72
  73 /**
  74  * Module parameter that is an estimate of the maximum number of users
  75  * that will be concurrently using eCryptfs. Set this to the right
  76  * value to balance performance and memory use.
  77  */
  78 unsigned int ecryptfs_number_of_users = ECRYPTFS_DEFAULT_NUM_USERS;
  79
  80 module_param(ecryptfs_number_of_users, uint, 0);
  81 MODULE_PARM_DESC(ecryptfs_number_of_users, "An estimate of the number of "
  82                  "concurrent users of eCryptfs");
  83
  84 void __ecryptfs_printk(const char *fmt, ...)
  85 {
  86         va_list args;
  87         va_start(args, fmt);
  88         if (fmt[1] == '7') { /* KERN_DEBUG */
  89                 if (ecryptfs_verbosity >= 1)
  90                         vprintk(fmt, args);
  91         } else
  92                 vprintk(fmt, args);
  93         va_end(args);
  94 }
  95
  96 /**
  97  * ecryptfs_init_persistent_file
  98  * @ecryptfs_dentry: Fully initialized eCryptfs dentry object, with
  99  *                   the lower dentry and the lower mount set
 100  *
 101  * eCryptfs only ever keeps a single open file for every lower
 102  * inode. All I/O operations to the lower inode occur through that
 103  * file. When the first eCryptfs dentry that interposes with the first
 104  * lower dentry for that inode is created, this function creates the
 105  * persistent file struct and associates it with the eCryptfs
 106  * inode. When the eCryptfs inode is destroyed, the file is closed.
 107  *
 108  * The persistent file will be opened with read/write permissions, if
 109  * possible. Otherwise, it is opened read-only.
 110  *
 111  * This function does nothing if a lower persistent file is already
 112  * associated with the eCryptfs inode.
 113  *
 114  * Returns zero on success; non-zero otherwise
 115  */
 116 int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry)
 117 {
 118         struct ecryptfs_inode_info *inode_info =
 119                 ecryptfs_inode_to_private(ecryptfs_dentry->d_inode);
 120         int rc = 0;
 121
 122         mutex_lock(&inode_info->lower_file_mutex);
 123         if (!inode_info->lower_file) {
 124                 struct dentry *lower_dentry;
 125                 struct vfsmount *lower_mnt =
 126                         ecryptfs_dentry_to_lower_mnt(ecryptfs_dentry);
 127
 128                 lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
 129                 rc = ecryptfs_privileged_open(&inode_info->lower_file,
 130                                                      lower_dentry, lower_mnt);
 131                 if (rc || IS_ERR(inode_info->lower_file)) {
 132                         printk(KERN_ERR "Error opening lower persistent file "
 133                                "for lower_dentry [0x%p] and lower_mnt [0x%p]; "
 134                                "rc = [%d]\n", lower_dentry, lower_mnt, rc);
 135                         rc = PTR_ERR(inode_info->lower_file);
 136                         inode_info->lower_file = NULL;
 137                 }
 138         }
 139         mutex_unlock(&inode_info->lower_file_mutex);
 140         return rc;
 141 }
 142
 143 /**
 144  * ecryptfs_interpose
 145  * @lower_dentry: Existing dentry in the lower filesystem
 146  * @dentry: ecryptfs' dentry
 147  * @sb: ecryptfs's super_block
 148  * @flags: flags to govern behavior of interpose procedure
 149  *
 150  * Interposes upper and lower dentries.
 151  *
 152  * Returns zero on success; non-zero otherwise
 153  */
 154 int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry,
 155                        struct super_block *sb, u32 flags)
 156 {
 157         struct inode *lower_inode;
 158         struct inode *inode;
 159         int rc = 0;
 160
 161         lower_inode = lower_dentry->d_inode;
 162         if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb)) {
 163                 rc = -EXDEV;
 164                 goto out;
 165         }
 166         if (!igrab(lower_inode)) {
 167                 rc = -ESTALE;
 168                 goto out;
 169         }
 170         inode = iget5_locked(sb, (unsigned long)lower_inode,
 171                              ecryptfs_inode_test, ecryptfs_inode_set,
 172                              lower_inode);
 173         if (!inode) {
 174                 rc = -EACCES;
 175                 iput(lower_inode);
 176                 goto out;
 177         }
 178         if (inode->i_state & I_NEW)
 179                 unlock_new_inode(inode);
 180         else
 181                 iput(lower_inode);
 182         if (S_ISLNK(lower_inode->i_mode))
 183                 inode->i_op = &ecryptfs_symlink_iops;
 184         else if (S_ISDIR(lower_inode->i_mode))
 185                 inode->i_op = &ecryptfs_dir_iops;
 186         if (S_ISDIR(lower_inode->i_mode))
 187                 inode->i_fop = &ecryptfs_dir_fops;
 188         if (special_file(lower_inode->i_mode))
 189                 init_special_inode(inode, lower_inode->i_mode,
 190                                    lower_inode->i_rdev);
 191         dentry->d_op = &ecryptfs_dops;
 192         if (flags & ECRYPTFS_INTERPOSE_FLAG_D_ADD)
 193                 d_add(dentry, inode);
 194         else
 195                 d_instantiate(dentry, inode);
 196         fsstack_copy_attr_all(inode, lower_inode, NULL);
 197         /* This size will be overwritten for real files w/ headers and
 198          * other metadata */
 199         fsstack_copy_inode_size(inode, lower_inode);
 200 out:
 201         return rc;
 202 }
 203
 204 enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig,
 205        ecryptfs_opt_cipher, ecryptfs_opt_ecryptfs_cipher,
 206        ecryptfs_opt_ecryptfs_key_bytes,
 207        ecryptfs_opt_passthrough, ecryptfs_opt_xattr_metadata,
 208        ecryptfs_opt_encrypted_view, ecryptfs_opt_err };
 209
 210 static const match_table_t tokens = {
 211         {ecryptfs_opt_sig, "sig=%s"},
 212         {ecryptfs_opt_ecryptfs_sig, "ecryptfs_sig=%s"},
 213         {ecryptfs_opt_cipher, "cipher=%s"},
 214         {ecryptfs_opt_ecryptfs_cipher, "ecryptfs_cipher=%s"},
 215         {ecryptfs_opt_ecryptfs_key_bytes, "ecryptfs_key_bytes=%u"},
 216         {ecryptfs_opt_passthrough, "ecryptfs_passthrough"},
 217         {ecryptfs_opt_xattr_metadata, "ecryptfs_xattr_metadata"},
 218         {ecryptfs_opt_encrypted_view, "ecryptfs_encrypted_view"},
 219         {ecryptfs_opt_err, NULL}
 220 };
 221
 222 static int ecryptfs_init_global_auth_toks(
 223         struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
 224 {
 225         struct ecryptfs_global_auth_tok *global_auth_tok;
 226         int rc = 0;
 227
 228         list_for_each_entry(global_auth_tok,
 229                             &mount_crypt_stat->global_auth_tok_list,
 230                             mount_crypt_stat_list) {
 231                 rc = ecryptfs_keyring_auth_tok_for_sig(
 232                         &global_auth_tok->global_auth_tok_key,
 233                         &global_auth_tok->global_auth_tok,
 234                         global_auth_tok->sig);
 235                 if (rc) {
 236                         printk(KERN_ERR "Could not find valid key in user "
 237                                "session keyring for sig specified in mount "
 238                                "option: [%s]\n", global_auth_tok->sig);
 239                         global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID;
 240                         goto out;
 241                 } else
 242                         global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID;
 243         }
 244 out:
 245         return rc;
 246 }
 247
 248 static void ecryptfs_init_mount_crypt_stat(
 249         struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
 250 {
 251         memset((void *)mount_crypt_stat, 0,
 252                sizeof(struct ecryptfs_mount_crypt_stat));
 253         INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list);
 254         mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex);
 255         mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED;
 256 }
 257
 258 /**
 259  * ecryptfs_parse_options
 260  * @sb: The ecryptfs super block
 261  * @options: The options pased to the kernel
 262  *
 263  * Parse mount options:
 264  * debug=N         - ecryptfs_verbosity level for debug output
 265  * sig=XXX         - description(signature) of the key to use
 266  *
 267  * Returns the dentry object of the lower-level (lower/interposed)
 268  * directory; We want to mount our stackable file system on top of
 269  * that lower directory.
 270  *
 271  * The signature of the key to use must be the description of a key
 272  * already in the keyring. Mounting will fail if the key can not be
 273  * found.
 274  *
 275  * Returns zero on success; non-zero on error
 276  */
 277 static int ecryptfs_parse_options(struct super_block *sb, char *options)
 278 {
 279         char *p;
 280         int rc = 0;
 281         int sig_set = 0;
 282         int cipher_name_set = 0;
 283         int cipher_key_bytes;
 284         int cipher_key_bytes_set = 0;
 285         struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
 286                 &ecryptfs_superblock_to_private(sb)->mount_crypt_stat;
 287         substring_t args[MAX_OPT_ARGS];
 288         int token;
 289         char *sig_src;
 290         char *cipher_name_dst;
 291         char *cipher_name_src;
 292         char *cipher_key_bytes_src;
 293
 294         if (!options) {
 295                 rc = -EINVAL;
 296                 goto out;
 297         }
 298         ecryptfs_init_mount_crypt_stat(mount_crypt_stat);
 299         while ((p = strsep(&options, ",")) != NULL) {
 300                 if (!*p)
 301                         continue;
 302                 token = match_token(p, tokens, args);
 303                 switch (token) {
 304                 case ecryptfs_opt_sig:
 305                 case ecryptfs_opt_ecryptfs_sig:
 306                         sig_src = args[0].from;
 307                         rc = ecryptfs_add_global_auth_tok(mount_crypt_stat,
 308                                                           sig_src);
 309                         if (rc) {
 310                                 printk(KERN_ERR "Error attempting to register "
 311                                        "global sig; rc = [%d]\n", rc);
 312                                 goto out;
 313                         }
 314                         sig_set = 1;
 315                         break;
 316                 case ecryptfs_opt_cipher:
 317                 case ecryptfs_opt_ecryptfs_cipher:
 318                         cipher_name_src = args[0].from;
 319                         cipher_name_dst =
 320                                 mount_crypt_stat->
 321                                 global_default_cipher_name;
 322                         strncpy(cipher_name_dst, cipher_name_src,
 323                                 ECRYPTFS_MAX_CIPHER_NAME_SIZE);
 324                         ecryptfs_printk(KERN_DEBUG,
 325                                         "The mount_crypt_stat "
 326                                         "global_default_cipher_name set to: "
 327                                         "[%s]\n", cipher_name_dst);
 328                         cipher_name_set = 1;
 329                         break;
 330                 case ecryptfs_opt_ecryptfs_key_bytes:
 331                         cipher_key_bytes_src = args[0].from;
 332                         cipher_key_bytes =
 333                                 (int)simple_strtol(cipher_key_bytes_src,
 334                                                    &cipher_key_bytes_src, 0);
 335                         mount_crypt_stat->global_default_cipher_key_size =
 336                                 cipher_key_bytes;
 337                         ecryptfs_printk(KERN_DEBUG,
 338                                         "The mount_crypt_stat "
 339                                         "global_default_cipher_key_size "
 340                                         "set to: [%d]\n", mount_crypt_stat->
 341                                         global_default_cipher_key_size);
 342                         cipher_key_bytes_set = 1;
 343                         break;
 344                 case ecryptfs_opt_passthrough:
 345                         mount_crypt_stat->flags |=
 346                                 ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED;
 347                         break;
 348                 case ecryptfs_opt_xattr_metadata:
 349                         mount_crypt_stat->flags |=
 350                                 ECRYPTFS_XATTR_METADATA_ENABLED;
 351                         break;
 352                 case ecryptfs_opt_encrypted_view:
 353                         mount_crypt_stat->flags |=
 354                                 ECRYPTFS_XATTR_METADATA_ENABLED;
 355                         mount_crypt_stat->flags |=
 356                                 ECRYPTFS_ENCRYPTED_VIEW_ENABLED;
 357                         break;
 358                 case ecryptfs_opt_err:
 359                 default:
 360                         ecryptfs_printk(KERN_WARNING,
 361                                         "eCryptfs: unrecognized option '%s'\n",
 362                                         p);
 363                 }
 364         }
 365         if (!sig_set) {
 366                 rc = -EINVAL;
 367                 ecryptfs_printk(KERN_ERR, "You must supply at least one valid "
 368                                 "auth tok signature as a mount "
 369                                 "parameter; see the eCryptfs README\n");
 370                 goto out;
 371         }
 372         if (!cipher_name_set) {
 373                 int cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER);
 374
 375                 BUG_ON(cipher_name_len >= ECRYPTFS_MAX_CIPHER_NAME_SIZE);
 376
 377                 strcpy(mount_crypt_stat->global_default_cipher_name,
 378                        ECRYPTFS_DEFAULT_CIPHER);
 379         }
 380         if (!cipher_key_bytes_set) {
 381                 mount_crypt_stat->global_default_cipher_key_size = 0;
 382         }
 383         mutex_lock(&key_tfm_list_mutex);
 384         if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name,
 385                                  NULL))
 386                 rc = ecryptfs_add_new_key_tfm(
 387                         NULL, mount_crypt_stat->global_default_cipher_name,
 388                         mount_crypt_stat->global_default_cipher_key_size);
 389         mutex_unlock(&key_tfm_list_mutex);
 390         if (rc) {
 391                 printk(KERN_ERR "Error attempting to initialize cipher with "
 392                        "name = [%s] and key size = [%td]; rc = [%d]\n",
 393                        mount_crypt_stat->global_default_cipher_name,
 394                        mount_crypt_stat->global_default_cipher_key_size, rc);
 395                 rc = -EINVAL;
 396                 goto out;
 397         }
 398         rc = ecryptfs_init_global_auth_toks(mount_crypt_stat);
 399         if (rc) {
 400                 printk(KERN_WARNING "One or more global auth toks could not "
 401                        "properly register; rc = [%d]\n", rc);
 402         }
 403 out:
 404         return rc;
 405 }
 406
 407 struct kmem_cache *ecryptfs_sb_info_cache;
 408
 409 /**
 410  * ecryptfs_fill_super
 411  * @sb: The ecryptfs super block
 412  * @raw_data: The options passed to mount
 413  * @silent: Not used but required by function prototype
 414  *
 415  * Sets up what we can of the sb, rest is done in ecryptfs_read_super
 416  *
 417  * Returns zero on success; non-zero otherwise
 418  */
 419 static int
 420 ecryptfs_fill_super(struct super_block *sb, void *raw_data, int silent)
 421 {
 422         int rc = 0;
 423
 424         /* Released in ecryptfs_put_super() */
 425         ecryptfs_set_superblock_private(sb,
 426                                         kmem_cache_zalloc(ecryptfs_sb_info_cache,
 427                                                          GFP_KERNEL));
 428         if (!ecryptfs_superblock_to_private(sb)) {
 429                 ecryptfs_printk(KERN_WARNING, "Out of memory\n");
 430                 rc = -ENOMEM;
 431                 goto out;
 432         }
 433         sb->s_op = &ecryptfs_sops;
 434         /* Released through deactivate_super(sb) from get_sb_nodev */
 435         sb->s_root = d_alloc(NULL, &(const struct qstr) {
 436                              .hash = 0,.name = "/",.len = 1});
 437         if (!sb->s_root) {
 438                 ecryptfs_printk(KERN_ERR, "d_alloc failed\n");
 439                 rc = -ENOMEM;
 440                 goto out;
 441         }
 442         sb->s_root->d_op = &ecryptfs_dops;
 443         sb->s_root->d_sb = sb;
 444         sb->s_root->d_parent = sb->s_root;
 445         /* Released in d_release when dput(sb->s_root) is called */
 446         /* through deactivate_super(sb) from get_sb_nodev() */
 447         ecryptfs_set_dentry_private(sb->s_root,
 448                                     kmem_cache_zalloc(ecryptfs_dentry_info_cache,
 449                                                      GFP_KERNEL));
 450         if (!ecryptfs_dentry_to_private(sb->s_root)) {
 451                 ecryptfs_printk(KERN_ERR,
 452                                 "dentry_info_cache alloc failed\n");
 453                 rc = -ENOMEM;
 454                 goto out;
 455         }
 456         rc = 0;
 457 out:
 458         /* Should be able to rely on deactivate_super called from
 459          * get_sb_nodev */
 460         return rc;
 461 }
 462
 463 /**
 464  * ecryptfs_read_super
 465  * @sb: The ecryptfs super block
 466  * @dev_name: The path to mount over
 467  *
 468  * Read the super block of the lower filesystem, and use
 469  * ecryptfs_interpose to create our initial inode and super block
 470  * struct.
 471  */
 472 static int ecryptfs_read_super(struct super_block *sb, const char *dev_name)
 473 {
 474         int rc;
 475         struct nameidata nd;
 476         struct dentry *lower_root;
 477         struct vfsmount *lower_mnt;
 478
 479         memset(&nd, 0, sizeof(struct nameidata));
 480         rc = path_lookup(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &nd);
 481         if (rc) {
 482                 ecryptfs_printk(KERN_WARNING, "path_lookup() failed\n");
 483                 goto out;
 484         }
 485         lower_root = nd.path.dentry;
 486         lower_mnt = nd.path.mnt;
 487         ecryptfs_set_superblock_lower(sb, lower_root->d_sb);
 488         sb->s_maxbytes = lower_root->d_sb->s_maxbytes;
 489         sb->s_blocksize = lower_root->d_sb->s_blocksize;
 490         ecryptfs_set_dentry_lower(sb->s_root, lower_root);
 491         ecryptfs_set_dentry_lower_mnt(sb->s_root, lower_mnt);
 492         rc = ecryptfs_interpose(lower_root, sb->s_root, sb, 0);
 493         if (rc)
 494                 goto out_free;
 495         rc = 0;
 496         goto out;
 497 out_free:
 498         path_put(&nd.path);
 499 out:
 500         return rc;
 501 }
 502
 503 /**
 504  * ecryptfs_get_sb
 505  * @fs_type
 506  * @flags
 507  * @dev_name: The path to mount over
 508  * @raw_data: The options passed into the kernel
 509  *
 510  * The whole ecryptfs_get_sb process is broken into 4 functions:
 511  * ecryptfs_parse_options(): handle options passed to ecryptfs, if any
 512  * ecryptfs_fill_super(): used by get_sb_nodev, fills out the super_block
 513  *                        with as much information as it can before needing
 514  *                        the lower filesystem.
 515  * ecryptfs_read_super(): this accesses the lower filesystem and uses
 516  *                        ecryptfs_interpolate to perform most of the linking
 517  * ecryptfs_interpolate(): links the lower filesystem into ecryptfs
 518  */
 519 static int ecryptfs_get_sb(struct file_system_type *fs_type, int flags,
 520                         const char *dev_name, void *raw_data,
 521                         struct vfsmount *mnt)
 522 {
 523         int rc;
 524         struct super_block *sb;
 525
 526         rc = get_sb_nodev(fs_type, flags, raw_data, ecryptfs_fill_super, mnt);
 527         if (rc < 0) {
 528                 printk(KERN_ERR "Getting sb failed; rc = [%d]\n", rc);
 529                 goto out;
 530         }
 531         sb = mnt->mnt_sb;
 532         rc = ecryptfs_parse_options(sb, raw_data);
 533         if (rc) {
 534                 printk(KERN_ERR "Error parsing options; rc = [%d]\n", rc);
 535                 goto out_abort;
 536         }
 537         rc = ecryptfs_read_super(sb, dev_name);
 538         if (rc) {
 539                 printk(KERN_ERR "Reading sb failed; rc = [%d]\n", rc);
 540                 goto out_abort;
 541         }
 542         goto out;
 543 out_abort:
 544         dput(sb->s_root);
 545         up_write(&sb->s_umount);
 546         deactivate_super(sb);
 547 out:
 548         return rc;
 549 }
 550
 551 /**
 552  * ecryptfs_kill_block_super
 553  * @sb: The ecryptfs super block
 554  *
 555  * Used to bring the superblock down and free the private data.
 556  * Private data is free'd in ecryptfs_put_super()
 557  */
 558 static void ecryptfs_kill_block_super(struct super_block *sb)
 559 {
 560         generic_shutdown_super(sb);
 561 }
 562
 563 static struct file_system_type ecryptfs_fs_type = {
 564         .owner = THIS_MODULE,
 565         .name = "ecryptfs",
 566         .get_sb = ecryptfs_get_sb,
 567         .kill_sb = ecryptfs_kill_block_super,
 568         .fs_flags = 0
 569 };
 570
 571 /**
 572  * inode_info_init_once
 573  *
 574  * Initializes the ecryptfs_inode_info_cache when it is created
 575  */
 576 static void
 577 inode_info_init_once(void *vptr)
 578 {
 579         struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr;
 580
 581         inode_init_once(&ei->vfs_inode);
 582 }
 583
 584 static struct ecryptfs_cache_info {
 585         struct kmem_cache **cache;
 586         const char *name;
 587         size_t size;
 588         void (*ctor)(void *obj);
 589 } ecryptfs_cache_infos[] = {
 590         {
 591                 .cache = &ecryptfs_auth_tok_list_item_cache,
 592                 .name = "ecryptfs_auth_tok_list_item",
 593                 .size = sizeof(struct ecryptfs_auth_tok_list_item),
 594         },
 595         {
 596                 .cache = &ecryptfs_file_info_cache,
 597                 .name = "ecryptfs_file_cache",
 598                 .size = sizeof(struct ecryptfs_file_info),
 599         },
 600         {
 601                 .cache = &ecryptfs_dentry_info_cache,
 602                 .name = "ecryptfs_dentry_info_cache",
 603                 .size = sizeof(struct ecryptfs_dentry_info),
 604         },
 605         {
 606                 .cache = &ecryptfs_inode_info_cache,
 607                 .name = "ecryptfs_inode_cache",
 608                 .size = sizeof(struct ecryptfs_inode_info),
 609                 .ctor = inode_info_init_once,
 610         },
 611         {
 612                 .cache = &ecryptfs_sb_info_cache,
 613                 .name = "ecryptfs_sb_cache",
 614                 .size = sizeof(struct ecryptfs_sb_info),
 615         },
 616         {
 617                 .cache = &ecryptfs_header_cache_1,
 618                 .name = "ecryptfs_headers_1",
 619                 .size = PAGE_CACHE_SIZE,
 620         },
 621         {
 622                 .cache = &ecryptfs_header_cache_2,
 623                 .name = "ecryptfs_headers_2",
 624                 .size = PAGE_CACHE_SIZE,
 625         },
 626         {
 627                 .cache = &ecryptfs_xattr_cache,
 628                 .name = "ecryptfs_xattr_cache",
 629                 .size = PAGE_CACHE_SIZE,
 630         },
 631         {
 632                 .cache = &ecryptfs_key_record_cache,
 633                 .name = "ecryptfs_key_record_cache",
 634                 .size = sizeof(struct ecryptfs_key_record),
 635         },
 636         {
 637                 .cache = &ecryptfs_key_sig_cache,
 638                 .name = "ecryptfs_key_sig_cache",
 639                 .size = sizeof(struct ecryptfs_key_sig),
 640         },
 641         {
 642                 .cache = &ecryptfs_global_auth_tok_cache,
 643                 .name = "ecryptfs_global_auth_tok_cache",
 644                 .size = sizeof(struct ecryptfs_global_auth_tok),
 645         },
 646         {
 647                 .cache = &ecryptfs_key_tfm_cache,
 648                 .name = "ecryptfs_key_tfm_cache",
 649                 .size = sizeof(struct ecryptfs_key_tfm),
 650         },
 651         {
 652                 .cache = &ecryptfs_open_req_cache,
 653                 .name = "ecryptfs_open_req_cache",
 654                 .size = sizeof(struct ecryptfs_open_req),
 655         },
 656 };
 657
 658 static void ecryptfs_free_kmem_caches(void)
 659 {
 660         int i;
 661
 662         for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
 663                 struct ecryptfs_cache_info *info;
 664
 665                 info = &ecryptfs_cache_infos[i];
 666                 if (*(info->cache))
 667                         kmem_cache_destroy(*(info->cache));
 668         }
 669 }
 670
 671 /**
 672  * ecryptfs_init_kmem_caches
 673  *
 674  * Returns zero on success; non-zero otherwise
 675  */
 676 static int ecryptfs_init_kmem_caches(void)
 677 {
 678         int i;
 679
 680         for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
 681                 struct ecryptfs_cache_info *info;
 682
 683                 info = &ecryptfs_cache_infos[i];
 684                 *(info->cache) = kmem_cache_create(info->name, info->size,
 685                                 0, SLAB_HWCACHE_ALIGN, info->ctor);
 686                 if (!*(info->cache)) {
 687                         ecryptfs_free_kmem_caches();
 688                         ecryptfs_printk(KERN_WARNING, "%s: "
 689                                         "kmem_cache_create failed\n",
 690                                         info->name);
 691                         return -ENOMEM;
 692                 }
 693         }
 694         return 0;
 695 }
 696
 697 static struct kobject *ecryptfs_kobj;
 698
 699 static ssize_t version_show(struct kobject *kobj,
 700                             struct kobj_attribute *attr, char *buff)
 701 {
 702         return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK);
 703 }
 704
 705 static struct kobj_attribute version_attr = __ATTR_RO(version);
 706
 707 static struct attribute *attributes[] = {
 708         &version_attr.attr,
 709         NULL,
 710 };
 711
 712 static struct attribute_group attr_group = {
 713         .attrs = attributes,
 714 };
 715
 716 static int do_sysfs_registration(void)
 717 {
 718         int rc;
 719
 720         ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj);
 721         if (!ecryptfs_kobj) {
 722                 printk(KERN_ERR "Unable to create ecryptfs kset\n");
 723                 rc = -ENOMEM;
 724                 goto out;
 725         }
 726         rc = sysfs_create_group(ecryptfs_kobj, &attr_group);
 727         if (rc) {
 728                 printk(KERN_ERR
 729                        "Unable to create ecryptfs version attributes\n");
 730                 kobject_put(ecryptfs_kobj);
 731         }
 732 out:
 733         return rc;
 734 }
 735
 736 static void do_sysfs_unregistration(void)
 737 {
 738         sysfs_remove_group(ecryptfs_kobj, &attr_group);
 739         kobject_put(ecryptfs_kobj);
 740 }
 741
 742 static int __init ecryptfs_init(void)
 743 {
 744         int rc;
 745
 746         if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_CACHE_SIZE) {
 747                 rc = -EINVAL;
 748                 ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is "
 749                                 "larger than the host's page size, and so "
 750                                 "eCryptfs cannot run on this system. The "
 751                                 "default eCryptfs extent size is [%d] bytes; "
 752                                 "the page size is [%d] bytes.\n",
 753                                 ECRYPTFS_DEFAULT_EXTENT_SIZE, PAGE_CACHE_SIZE);
 754                 goto out;
 755         }
 756         rc = ecryptfs_init_kmem_caches();
 757         if (rc) {
 758                 printk(KERN_ERR
 759                        "Failed to allocate one or more kmem_cache objects\n");
 760                 goto out;
 761         }
 762         rc = register_filesystem(&ecryptfs_fs_type);
 763         if (rc) {
 764                 printk(KERN_ERR "Failed to register filesystem\n");
 765                 goto out_free_kmem_caches;
 766         }
 767         rc = do_sysfs_registration();
 768         if (rc) {
 769                 printk(KERN_ERR "sysfs registration failed\n");
 770                 goto out_unregister_filesystem;
 771         }
 772         rc = ecryptfs_init_kthread();
 773         if (rc) {
 774                 printk(KERN_ERR "%s: kthread initialization failed; "
 775                        "rc = [%d]\n", __func__, rc);
 776                 goto out_do_sysfs_unregistration;
 777         }
 778         rc = ecryptfs_init_messaging();
 779         if (rc) {
 780                 printk(KERN_ERR "Failure occured while attempting to "
 781                                 "initialize the communications channel to "
 782                                 "ecryptfsd\n");
 783                 goto out_destroy_kthread;
 784         }
 785         rc = ecryptfs_init_crypto();
 786         if (rc) {
 787                 printk(KERN_ERR "Failure whilst attempting to init crypto; "
 788                        "rc = [%d]\n", rc);
 789                 goto out_release_messaging;
 790         }
 791         if (ecryptfs_verbosity > 0)
 792                 printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values "
 793                         "will be written to the syslog!\n", ecryptfs_verbosity);
 794
 795         goto out;
 796 out_release_messaging:
 797         ecryptfs_release_messaging();
 798 out_destroy_kthread:
 799         ecryptfs_destroy_kthread();
 800 out_do_sysfs_unregistration:
 801         do_sysfs_unregistration();
 802 out_unregister_filesystem:
 803         unregister_filesystem(&ecryptfs_fs_type);
 804 out_free_kmem_caches:
 805         ecryptfs_free_kmem_caches();
 806 out:
 807         return rc;
 808 }
 809
 810 static void __exit ecryptfs_exit(void)
 811 {
 812         int rc;
 813
 814         rc = ecryptfs_destroy_crypto();
 815         if (rc)
 816                 printk(KERN_ERR "Failure whilst attempting to destroy crypto; "
 817                        "rc = [%d]\n", rc);
 818         ecryptfs_release_messaging();
 819         ecryptfs_destroy_kthread();
 820         do_sysfs_unregistration();
 821         unregister_filesystem(&ecryptfs_fs_type);
 822         ecryptfs_free_kmem_caches();
 823 }
 824
 825 MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>");
 826 MODULE_DESCRIPTION("eCryptfs");
 827
 828 MODULE_LICENSE("GPL");
 829
 830 module_init(ecryptfs_init)
 831 module_exit(ecryptfs_exit)