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