fs/ecryptfs/main.c

   1 /**
   2  * eCryptfs: Linux filesystem encryption layer
   3  *
   4  * Copyright (C) 1997-2003 Erez Zadok
   5  * Copyright (C) 2001-2003 Stony Brook University
   6  * Copyright (C) 2004-2007 International Business Machines Corp.
   7  *   Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
   8  *              Michael C. Thompson <mcthomps@us.ibm.com>
   9  *              Tyler Hicks <tyhicks@ou.edu>
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License as
  13  * published by the Free Software Foundation; either version 2 of the
  14  * License, or (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful, but
  17  * WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19  * General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  24  * 02111-1307, USA.
  25  */
  26
  27 #include <linux/dcache.h>
  28 #include <linux/file.h>
  29 #include <linux/module.h>
  30 #include <linux/namei.h>
  31 #include <linux/skbuff.h>
  32 #include <linux/crypto.h>
  33 #include <linux/mount.h>
  34 #include <linux/pagemap.h>
  35 #include <linux/key.h>
  36 #include <linux/parser.h>
  37 #include <linux/fs_stack.h>
  38 #include <linux/slab.h>
  39 #include <linux/magic.h>
  40 #include "ecryptfs_kernel.h"
  41
  42 /**
  43  * Module parameter that defines the ecryptfs_verbosity level.
  44  */
  45 int ecryptfs_verbosity = 0;
  46
  47 module_param(ecryptfs_verbosity, int, 0);
  48 MODULE_PARM_DESC(ecryptfs_verbosity,
  49                  "Initial verbosity level (0 or 1; defaults to "
  50                  "0, which is Quiet)");
  51
  52 /**
  53  * Module parameter that defines the number of message buffer 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 from ecryptfsd.  The actual sleep time will be, more than
  64  * likely, a small amount greater than this specified value, but only less if
  65  * the 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 void __ecryptfs_printk(const char *fmt, ...)
  87 {
  88         va_list args;
  89         va_start(args, fmt);
  90         if (fmt[1] == '7') { /* KERN_DEBUG */
  91                 if (ecryptfs_verbosity >= 1)
  92                         vprintk(fmt, args);
  93         } else
  94                 vprintk(fmt, args);
  95         va_end(args);
  96 }
  97
  98 /**
  99  * ecryptfs_init_persistent_file
 100  * @ecryptfs_dentry: Fully initialized eCryptfs dentry object, with
 101  *                   the lower dentry and the lower mount set
 102  *
 103  * eCryptfs only ever keeps a single open file for every lower
 104  * inode. All I/O operations to the lower inode occur through that
 105  * file. When the first eCryptfs dentry that interposes with the first
 106  * lower dentry for that inode is created, this function creates the
 107  * persistent file struct and associates it with the eCryptfs
 108  * inode. When the eCryptfs inode is destroyed, the file is closed.
 109  *
 110  * The persistent file will be opened with read/write permissions, if
 111  * possible. Otherwise, it is opened read-only.
 112  *
 113  * This function does nothing if a lower persistent file is already
 114  * associated with the eCryptfs inode.
 115  *
 116  * Returns zero on success; non-zero otherwise
 117  */
 118 int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry)
 119 {
 120         const struct cred *cred = current_cred();
 121         struct ecryptfs_inode_info *inode_info =
 122                 ecryptfs_inode_to_private(ecryptfs_dentry->d_inode);
 123         int rc = 0;
 124
 125         mutex_lock(&inode_info->lower_file_mutex);
 126         if (!inode_info->lower_file) {
 127                 struct dentry *lower_dentry;
 128                 struct vfsmount *lower_mnt =
 129                         ecryptfs_dentry_to_lower_mnt(ecryptfs_dentry);
 130
 131                 lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
 132                 rc = ecryptfs_privileged_open(&inode_info->lower_file,
 133                                               lower_dentry, lower_mnt, cred);
 134                 if (rc) {
 135                         printk(KERN_ERR "Error opening lower persistent file "
 136                                "for lower_dentry [0x%p] and lower_mnt [0x%p]; "
 137                                "rc = [%d]\n", lower_dentry, lower_mnt, rc);
 138                         inode_info->lower_file = NULL;
 139                 }
 140         }
 141         mutex_unlock(&inode_info->lower_file_mutex);
 142         return rc;
 143 }
 144
 145 static struct inode *ecryptfs_get_inode(struct inode *lower_inode,
 146                        struct super_block *sb)
 147 {
 148         struct inode *inode;
 149         int rc = 0;
 150
 151         if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb)) {
 152                 rc = -EXDEV;
 153                 goto out;
 154         }
 155         if (!igrab(lower_inode)) {
 156                 rc = -ESTALE;
 157                 goto out;
 158         }
 159         inode = iget5_locked(sb, (unsigned long)lower_inode,
 160                              ecryptfs_inode_test, ecryptfs_inode_set,
 161                              lower_inode);
 162         if (!inode) {
 163                 rc = -EACCES;
 164                 iput(lower_inode);
 165                 goto out;
 166         }
 167         if (inode->i_state & I_NEW)
 168                 unlock_new_inode(inode);
 169         else
 170                 iput(lower_inode);
 171         if (S_ISLNK(lower_inode->i_mode))
 172                 inode->i_op = &ecryptfs_symlink_iops;
 173         else if (S_ISDIR(lower_inode->i_mode))
 174                 inode->i_op = &ecryptfs_dir_iops;
 175         if (S_ISDIR(lower_inode->i_mode))
 176                 inode->i_fop = &ecryptfs_dir_fops;
 177         if (special_file(lower_inode->i_mode))
 178                 init_special_inode(inode, lower_inode->i_mode,
 179                                    lower_inode->i_rdev);
 180         fsstack_copy_attr_all(inode, lower_inode);
 181         /* This size will be overwritten for real files w/ headers and
 182          * other metadata */
 183         fsstack_copy_inode_size(inode, lower_inode);
 184         return inode;
 185 out:
 186         return ERR_PTR(rc);
 187 }
 188
 189 /**
 190  * ecryptfs_interpose
 191  * @lower_dentry: Existing dentry in the lower filesystem
 192  * @dentry: ecryptfs' dentry
 193  * @sb: ecryptfs's super_block
 194  * @flags: flags to govern behavior of interpose procedure
 195  *
 196  * Interposes upper and lower dentries.
 197  *
 198  * Returns zero on success; non-zero otherwise
 199  */
 200 int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry,
 201                        struct super_block *sb, u32 flags)
 202 {
 203         struct inode *lower_inode = lower_dentry->d_inode;
 204         struct inode *inode = ecryptfs_get_inode(lower_inode, sb);
 205         if (IS_ERR(inode))
 206                 return PTR_ERR(inode);
 207         if (flags & ECRYPTFS_INTERPOSE_FLAG_D_ADD)
 208                 d_add(dentry, inode);
 209         else
 210                 d_instantiate(dentry, inode);
 211         return 0;
 212 }
 213
 214 enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig,
 215        ecryptfs_opt_cipher, ecryptfs_opt_ecryptfs_cipher,
 216        ecryptfs_opt_ecryptfs_key_bytes,
 217        ecryptfs_opt_passthrough, ecryptfs_opt_xattr_metadata,
 218        ecryptfs_opt_encrypted_view, ecryptfs_opt_fnek_sig,
 219        ecryptfs_opt_fn_cipher, ecryptfs_opt_fn_cipher_key_bytes,
 220        ecryptfs_opt_unlink_sigs, ecryptfs_opt_mount_auth_tok_only,
 221        ecryptfs_opt_check_dev_ruid,
 222        ecryptfs_opt_err };
 223
 224 static const match_table_t tokens = {
 225         {ecryptfs_opt_sig, "sig=%s"},
 226         {ecryptfs_opt_ecryptfs_sig, "ecryptfs_sig=%s"},
 227         {ecryptfs_opt_cipher, "cipher=%s"},
 228         {ecryptfs_opt_ecryptfs_cipher, "ecryptfs_cipher=%s"},
 229         {ecryptfs_opt_ecryptfs_key_bytes, "ecryptfs_key_bytes=%u"},
 230         {ecryptfs_opt_passthrough, "ecryptfs_passthrough"},
 231         {ecryptfs_opt_xattr_metadata, "ecryptfs_xattr_metadata"},
 232         {ecryptfs_opt_encrypted_view, "ecryptfs_encrypted_view"},
 233         {ecryptfs_opt_fnek_sig, "ecryptfs_fnek_sig=%s"},
 234         {ecryptfs_opt_fn_cipher, "ecryptfs_fn_cipher=%s"},
 235         {ecryptfs_opt_fn_cipher_key_bytes, "ecryptfs_fn_key_bytes=%u"},
 236         {ecryptfs_opt_unlink_sigs, "ecryptfs_unlink_sigs"},
 237         {ecryptfs_opt_mount_auth_tok_only, "ecryptfs_mount_auth_tok_only"},
 238         {ecryptfs_opt_check_dev_ruid, "ecryptfs_check_dev_ruid"},
 239         {ecryptfs_opt_err, NULL}
 240 };
 241
 242 static int ecryptfs_init_global_auth_toks(
 243         struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
 244 {
 245         struct ecryptfs_global_auth_tok *global_auth_tok;
 246         int rc = 0;
 247
 248         list_for_each_entry(global_auth_tok,
 249                             &mount_crypt_stat->global_auth_tok_list,
 250                             mount_crypt_stat_list) {
 251                 rc = ecryptfs_keyring_auth_tok_for_sig(
 252                         &global_auth_tok->global_auth_tok_key,
 253                         &global_auth_tok->global_auth_tok,
 254                         global_auth_tok->sig);
 255                 if (rc) {
 256                         printk(KERN_ERR "Could not find valid key in user "
 257                                "session keyring for sig specified in mount "
 258                                "option: [%s]\n", global_auth_tok->sig);
 259                         global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID;
 260                         goto out;
 261                 } else
 262                         global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID;
 263         }
 264 out:
 265         return rc;
 266 }
 267
 268 static void ecryptfs_init_mount_crypt_stat(
 269         struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
 270 {
 271         memset((void *)mount_crypt_stat, 0,
 272                sizeof(struct ecryptfs_mount_crypt_stat));
 273         INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list);
 274         mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex);
 275         mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED;
 276 }
 277
 278 /**
 279  * ecryptfs_parse_options
 280  * @sb: The ecryptfs super block
 281  * @options: The options pased to the kernel
 282  * @check_ruid: set to 1 if device uid should be checked against the ruid
 283  *
 284  * Parse mount options:
 285  * debug=N         - ecryptfs_verbosity level for debug output
 286  * sig=XXX         - description(signature) of the key to use
 287  *
 288  * Returns the dentry object of the lower-level (lower/interposed)
 289  * directory; We want to mount our stackable file system on top of
 290  * that lower directory.
 291  *
 292  * The signature of the key to use must be the description of a key
 293  * already in the keyring. Mounting will fail if the key can not be
 294  * found.
 295  *
 296  * Returns zero on success; non-zero on error
 297  */
 298 static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options,
 299                                   uid_t *check_ruid)
 300 {
 301         char *p;
 302         int rc = 0;
 303         int sig_set = 0;
 304         int cipher_name_set = 0;
 305         int fn_cipher_name_set = 0;
 306         int cipher_key_bytes;
 307         int cipher_key_bytes_set = 0;
 308         int fn_cipher_key_bytes;
 309         int fn_cipher_key_bytes_set = 0;
 310         struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
 311                 &sbi->mount_crypt_stat;
 312         substring_t args[MAX_OPT_ARGS];
 313         int token;
 314         char *sig_src;
 315         char *cipher_name_dst;
 316         char *cipher_name_src;
 317         char *fn_cipher_name_dst;
 318         char *fn_cipher_name_src;
 319         char *fnek_dst;
 320         char *fnek_src;
 321         char *cipher_key_bytes_src;
 322         char *fn_cipher_key_bytes_src;
 323
 324         *check_ruid = 0;
 325
 326         if (!options) {
 327                 rc = -EINVAL;
 328                 goto out;
 329         }
 330         ecryptfs_init_mount_crypt_stat(mount_crypt_stat);
 331         while ((p = strsep(&options, ",")) != NULL) {
 332                 if (!*p)
 333                         continue;
 334                 token = match_token(p, tokens, args);
 335                 switch (token) {
 336                 case ecryptfs_opt_sig:
 337                 case ecryptfs_opt_ecryptfs_sig:
 338                         sig_src = args[0].from;
 339                         rc = ecryptfs_add_global_auth_tok(mount_crypt_stat,
 340                                                           sig_src, 0);
 341                         if (rc) {
 342                                 printk(KERN_ERR "Error attempting to register "
 343                                        "global sig; rc = [%d]\n", rc);
 344                                 goto out;
 345                         }
 346                         sig_set = 1;
 347                         break;
 348                 case ecryptfs_opt_cipher:
 349                 case ecryptfs_opt_ecryptfs_cipher:
 350                         cipher_name_src = args[0].from;
 351                         cipher_name_dst =
 352                                 mount_crypt_stat->
 353                                 global_default_cipher_name;
 354                         strncpy(cipher_name_dst, cipher_name_src,
 355                                 ECRYPTFS_MAX_CIPHER_NAME_SIZE);
 356                         cipher_name_dst[ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0';
 357                         cipher_name_set = 1;
 358                         break;
 359                 case ecryptfs_opt_ecryptfs_key_bytes:
 360                         cipher_key_bytes_src = args[0].from;
 361                         cipher_key_bytes =
 362                                 (int)simple_strtol(cipher_key_bytes_src,
 363                                                    &cipher_key_bytes_src, 0);
 364                         mount_crypt_stat->global_default_cipher_key_size =
 365                                 cipher_key_bytes;
 366                         cipher_key_bytes_set = 1;
 367                         break;
 368                 case ecryptfs_opt_passthrough:
 369                         mount_crypt_stat->flags |=
 370                                 ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED;
 371                         break;
 372                 case ecryptfs_opt_xattr_metadata:
 373                         mount_crypt_stat->flags |=
 374                                 ECRYPTFS_XATTR_METADATA_ENABLED;
 375                         break;
 376                 case ecryptfs_opt_encrypted_view:
 377                         mount_crypt_stat->flags |=
 378                                 ECRYPTFS_XATTR_METADATA_ENABLED;
 379                         mount_crypt_stat->flags |=
 380                                 ECRYPTFS_ENCRYPTED_VIEW_ENABLED;
 381                         break;
 382                 case ecryptfs_opt_fnek_sig:
 383                         fnek_src = args[0].from;
 384                         fnek_dst =
 385                                 mount_crypt_stat->global_default_fnek_sig;
 386                         strncpy(fnek_dst, fnek_src, ECRYPTFS_SIG_SIZE_HEX);
 387                         mount_crypt_stat->global_default_fnek_sig[
 388                                 ECRYPTFS_SIG_SIZE_HEX] = '\0';
 389                         rc = ecryptfs_add_global_auth_tok(
 390                                 mount_crypt_stat,
 391                                 mount_crypt_stat->global_default_fnek_sig,
 392                                 ECRYPTFS_AUTH_TOK_FNEK);
 393                         if (rc) {
 394                                 printk(KERN_ERR "Error attempting to register "
 395                                        "global fnek sig [%s]; rc = [%d]\n",
 396                                        mount_crypt_stat->global_default_fnek_sig,
 397                                        rc);
 398                                 goto out;
 399                         }
 400                         mount_crypt_stat->flags |=
 401                                 (ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
 402                                  | ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK);
 403                         break;
 404                 case ecryptfs_opt_fn_cipher:
 405                         fn_cipher_name_src = args[0].from;
 406                         fn_cipher_name_dst =
 407                                 mount_crypt_stat->global_default_fn_cipher_name;
 408                         strncpy(fn_cipher_name_dst, fn_cipher_name_src,
 409                                 ECRYPTFS_MAX_CIPHER_NAME_SIZE);
 410                         mount_crypt_stat->global_default_fn_cipher_name[
 411                                 ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0';
 412                         fn_cipher_name_set = 1;
 413                         break;
 414                 case ecryptfs_opt_fn_cipher_key_bytes:
 415                         fn_cipher_key_bytes_src = args[0].from;
 416                         fn_cipher_key_bytes =
 417                                 (int)simple_strtol(fn_cipher_key_bytes_src,
 418                                                    &fn_cipher_key_bytes_src, 0);
 419                         mount_crypt_stat->global_default_fn_cipher_key_bytes =
 420                                 fn_cipher_key_bytes;
 421                         fn_cipher_key_bytes_set = 1;
 422                         break;
 423                 case ecryptfs_opt_unlink_sigs:
 424                         mount_crypt_stat->flags |= ECRYPTFS_UNLINK_SIGS;
 425                         break;
 426                 case ecryptfs_opt_mount_auth_tok_only:
 427                         mount_crypt_stat->flags |=
 428                                 ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY;
 429                         break;
 430                 case ecryptfs_opt_check_dev_ruid:
 431                         *check_ruid = 1;
 432                         break;
 433                 case ecryptfs_opt_err:
 434                 default:
 435                         printk(KERN_WARNING
 436                                "%s: eCryptfs: unrecognized option [%s]\n",
 437                                __func__, p);
 438                 }
 439         }
 440         if (!sig_set) {
 441                 rc = -EINVAL;
 442                 ecryptfs_printk(KERN_ERR, "You must supply at least one valid "
 443                                 "auth tok signature as a mount "
 444                                 "parameter; see the eCryptfs README\n");
 445                 goto out;
 446         }
 447         if (!cipher_name_set) {
 448                 int cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER);
 449
 450                 BUG_ON(cipher_name_len >= ECRYPTFS_MAX_CIPHER_NAME_SIZE);
 451                 strcpy(mount_crypt_stat->global_default_cipher_name,
 452                        ECRYPTFS_DEFAULT_CIPHER);
 453         }
 454         if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
 455             && !fn_cipher_name_set)
 456                 strcpy(mount_crypt_stat->global_default_fn_cipher_name,
 457                        mount_crypt_stat->global_default_cipher_name);
 458         if (!cipher_key_bytes_set)
 459                 mount_crypt_stat->global_default_cipher_key_size = 0;
 460         if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
 461             && !fn_cipher_key_bytes_set)
 462                 mount_crypt_stat->global_default_fn_cipher_key_bytes =
 463                         mount_crypt_stat->global_default_cipher_key_size;
 464         mutex_lock(&key_tfm_list_mutex);
 465         if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name,
 466                                  NULL)) {
 467                 rc = ecryptfs_add_new_key_tfm(
 468                         NULL, mount_crypt_stat->global_default_cipher_name,
 469                         mount_crypt_stat->global_default_cipher_key_size);
 470                 if (rc) {
 471                         printk(KERN_ERR "Error attempting to initialize "
 472                                "cipher with name = [%s] and key size = [%td]; "
 473                                "rc = [%d]\n",
 474                                mount_crypt_stat->global_default_cipher_name,
 475                                mount_crypt_stat->global_default_cipher_key_size,
 476                                rc);
 477                         rc = -EINVAL;
 478                         mutex_unlock(&key_tfm_list_mutex);
 479                         goto out;
 480                 }
 481         }
 482         if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
 483             && !ecryptfs_tfm_exists(
 484                     mount_crypt_stat->global_default_fn_cipher_name, NULL)) {
 485                 rc = ecryptfs_add_new_key_tfm(
 486                         NULL, mount_crypt_stat->global_default_fn_cipher_name,
 487                         mount_crypt_stat->global_default_fn_cipher_key_bytes);
 488                 if (rc) {
 489                         printk(KERN_ERR "Error attempting to initialize "
 490                                "cipher with name = [%s] and key size = [%td]; "
 491                                "rc = [%d]\n",
 492                                mount_crypt_stat->global_default_fn_cipher_name,
 493                                mount_crypt_stat->global_default_fn_cipher_key_bytes,
 494                                rc);
 495                         rc = -EINVAL;
 496                         mutex_unlock(&key_tfm_list_mutex);
 497                         goto out;
 498                 }
 499         }
 500         mutex_unlock(&key_tfm_list_mutex);
 501         rc = ecryptfs_init_global_auth_toks(mount_crypt_stat);
 502         if (rc)
 503                 printk(KERN_WARNING "One or more global auth toks could not "
 504                        "properly register; rc = [%d]\n", rc);
 505 out:
 506         return rc;
 507 }
 508
 509 struct kmem_cache *ecryptfs_sb_info_cache;
 510 static struct file_system_type ecryptfs_fs_type;
 511
 512 /**
 513  * ecryptfs_get_sb
 514  * @fs_type
 515  * @flags
 516  * @dev_name: The path to mount over
 517  * @raw_data: The options passed into the kernel
 518  */
 519 static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags,
 520                         const char *dev_name, void *raw_data)
 521 {
 522         struct super_block *s;
 523         struct ecryptfs_sb_info *sbi;
 524         struct ecryptfs_dentry_info *root_info;
 525         const char *err = "Getting sb failed";
 526         struct inode *inode;
 527         struct path path;
 528         uid_t check_ruid;
 529         int rc;
 530
 531         sbi = kmem_cache_zalloc(ecryptfs_sb_info_cache, GFP_KERNEL);
 532         if (!sbi) {
 533                 rc = -ENOMEM;
 534                 goto out;
 535         }
 536
 537         rc = ecryptfs_parse_options(sbi, raw_data, &check_ruid);
 538         if (rc) {
 539                 err = "Error parsing options";
 540                 goto out;
 541         }
 542
 543         s = sget(fs_type, NULL, set_anon_super, NULL);
 544         if (IS_ERR(s)) {
 545                 rc = PTR_ERR(s);
 546                 goto out;
 547         }
 548
 549         s->s_flags = flags;
 550         rc = bdi_setup_and_register(&sbi->bdi, "ecryptfs", BDI_CAP_MAP_COPY);
 551         if (rc)
 552                 goto out1;
 553
 554         ecryptfs_set_superblock_private(s, sbi);
 555         s->s_bdi = &sbi->bdi;
 556
 557         /* ->kill_sb() will take care of sbi after that point */
 558         sbi = NULL;
 559         s->s_op = &ecryptfs_sops;
 560         s->s_d_op = &ecryptfs_dops;
 561
 562         err = "Reading sb failed";
 563         rc = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path);
 564         if (rc) {
 565                 ecryptfs_printk(KERN_WARNING, "kern_path() failed\n");
 566                 goto out1;
 567         }
 568         if (path.dentry->d_sb->s_type == &ecryptfs_fs_type) {
 569                 rc = -EINVAL;
 570                 printk(KERN_ERR "Mount on filesystem of type "
 571                         "eCryptfs explicitly disallowed due to "
 572                         "known incompatibilities\n");
 573                 goto out_free;
 574         }
 575
 576         if (check_ruid && path.dentry->d_inode->i_uid != current_uid()) {
 577                 rc = -EPERM;
 578                 printk(KERN_ERR "Mount of device (uid: %d) not owned by "
 579                        "requested user (uid: %d)\n",
 580                        path.dentry->d_inode->i_uid, current_uid());
 581                 goto out_free;
 582         }
 583
 584         ecryptfs_set_superblock_lower(s, path.dentry->d_sb);
 585         s->s_maxbytes = path.dentry->d_sb->s_maxbytes;
 586         s->s_blocksize = path.dentry->d_sb->s_blocksize;
 587         s->s_magic = ECRYPTFS_SUPER_MAGIC;
 588
 589         inode = ecryptfs_get_inode(path.dentry->d_inode, s);
 590         rc = PTR_ERR(inode);
 591         if (IS_ERR(inode))
 592                 goto out_free;
 593
 594         s->s_root = d_alloc_root(inode);
 595         if (!s->s_root) {
 596                 iput(inode);
 597                 rc = -ENOMEM;
 598                 goto out_free;
 599         }
 600
 601         rc = -ENOMEM;
 602         root_info = kmem_cache_zalloc(ecryptfs_dentry_info_cache, GFP_KERNEL);
 603         if (!root_info)
 604                 goto out_free;
 605
 606         /* ->kill_sb() will take care of root_info */
 607         ecryptfs_set_dentry_private(s->s_root, root_info);
 608         ecryptfs_set_dentry_lower(s->s_root, path.dentry);
 609         ecryptfs_set_dentry_lower_mnt(s->s_root, path.mnt);
 610
 611         s->s_flags |= MS_ACTIVE;
 612         return dget(s->s_root);
 613
 614 out_free:
 615         path_put(&path);
 616 out1:
 617         deactivate_locked_super(s);
 618 out:
 619         if (sbi) {
 620                 ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat);
 621                 kmem_cache_free(ecryptfs_sb_info_cache, sbi);
 622         }
 623         printk(KERN_ERR "%s; rc = [%d]\n", err, rc);
 624         return ERR_PTR(rc);
 625 }
 626
 627 /**
 628  * ecryptfs_kill_block_super
 629  * @sb: The ecryptfs super block
 630  *
 631  * Used to bring the superblock down and free the private data.
 632  */
 633 static void ecryptfs_kill_block_super(struct super_block *sb)
 634 {
 635         struct ecryptfs_sb_info *sb_info = ecryptfs_superblock_to_private(sb);
 636         kill_anon_super(sb);
 637         if (!sb_info)
 638                 return;
 639         ecryptfs_destroy_mount_crypt_stat(&sb_info->mount_crypt_stat);
 640         bdi_destroy(&sb_info->bdi);
 641         kmem_cache_free(ecryptfs_sb_info_cache, sb_info);
 642 }
 643
 644 static struct file_system_type ecryptfs_fs_type = {
 645         .owner = THIS_MODULE,
 646         .name = "ecryptfs",
 647         .mount = ecryptfs_mount,
 648         .kill_sb = ecryptfs_kill_block_super,
 649         .fs_flags = 0
 650 };
 651
 652 /**
 653  * inode_info_init_once
 654  *
 655  * Initializes the ecryptfs_inode_info_cache when it is created
 656  */
 657 static void
 658 inode_info_init_once(void *vptr)
 659 {
 660         struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr;
 661
 662         inode_init_once(&ei->vfs_inode);
 663 }
 664
 665 static struct ecryptfs_cache_info {
 666         struct kmem_cache **cache;
 667         const char *name;
 668         size_t size;
 669         void (*ctor)(void *obj);
 670 } ecryptfs_cache_infos[] = {
 671         {
 672                 .cache = &ecryptfs_auth_tok_list_item_cache,
 673                 .name = "ecryptfs_auth_tok_list_item",
 674                 .size = sizeof(struct ecryptfs_auth_tok_list_item),
 675         },
 676         {
 677                 .cache = &ecryptfs_file_info_cache,
 678                 .name = "ecryptfs_file_cache",
 679                 .size = sizeof(struct ecryptfs_file_info),
 680         },
 681         {
 682                 .cache = &ecryptfs_dentry_info_cache,
 683                 .name = "ecryptfs_dentry_info_cache",
 684                 .size = sizeof(struct ecryptfs_dentry_info),
 685         },
 686         {
 687                 .cache = &ecryptfs_inode_info_cache,
 688                 .name = "ecryptfs_inode_cache",
 689                 .size = sizeof(struct ecryptfs_inode_info),
 690                 .ctor = inode_info_init_once,
 691         },
 692         {
 693                 .cache = &ecryptfs_sb_info_cache,
 694                 .name = "ecryptfs_sb_cache",
 695                 .size = sizeof(struct ecryptfs_sb_info),
 696         },
 697         {
 698                 .cache = &ecryptfs_header_cache_1,
 699                 .name = "ecryptfs_headers_1",
 700                 .size = PAGE_CACHE_SIZE,
 701         },
 702         {
 703                 .cache = &ecryptfs_header_cache_2,
 704                 .name = "ecryptfs_headers_2",
 705                 .size = PAGE_CACHE_SIZE,
 706         },
 707         {
 708                 .cache = &ecryptfs_xattr_cache,
 709                 .name = "ecryptfs_xattr_cache",
 710                 .size = PAGE_CACHE_SIZE,
 711         },
 712         {
 713                 .cache = &ecryptfs_key_record_cache,
 714                 .name = "ecryptfs_key_record_cache",
 715                 .size = sizeof(struct ecryptfs_key_record),
 716         },
 717         {
 718                 .cache = &ecryptfs_key_sig_cache,
 719                 .name = "ecryptfs_key_sig_cache",
 720                 .size = sizeof(struct ecryptfs_key_sig),
 721         },
 722         {
 723                 .cache = &ecryptfs_global_auth_tok_cache,
 724                 .name = "ecryptfs_global_auth_tok_cache",
 725                 .size = sizeof(struct ecryptfs_global_auth_tok),
 726         },
 727         {
 728                 .cache = &ecryptfs_key_tfm_cache,
 729                 .name = "ecryptfs_key_tfm_cache",
 730                 .size = sizeof(struct ecryptfs_key_tfm),
 731         },
 732         {
 733                 .cache = &ecryptfs_open_req_cache,
 734                 .name = "ecryptfs_open_req_cache",
 735                 .size = sizeof(struct ecryptfs_open_req),
 736         },
 737 };
 738
 739 static void ecryptfs_free_kmem_caches(void)
 740 {
 741         int i;
 742
 743         for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
 744                 struct ecryptfs_cache_info *info;
 745
 746                 info = &ecryptfs_cache_infos[i];
 747                 if (*(info->cache))
 748                         kmem_cache_destroy(*(info->cache));
 749         }
 750 }
 751
 752 /**
 753  * ecryptfs_init_kmem_caches
 754  *
 755  * Returns zero on success; non-zero otherwise
 756  */
 757 static int ecryptfs_init_kmem_caches(void)
 758 {
 759         int i;
 760
 761         for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
 762                 struct ecryptfs_cache_info *info;
 763
 764                 info = &ecryptfs_cache_infos[i];
 765                 *(info->cache) = kmem_cache_create(info->name, info->size,
 766                                 0, SLAB_HWCACHE_ALIGN, info->ctor);
 767                 if (!*(info->cache)) {
 768                         ecryptfs_free_kmem_caches();
 769                         ecryptfs_printk(KERN_WARNING, "%s: "
 770                                         "kmem_cache_create failed\n",
 771                                         info->name);
 772                         return -ENOMEM;
 773                 }
 774         }
 775         return 0;
 776 }
 777
 778 static struct kobject *ecryptfs_kobj;
 779
 780 static ssize_t version_show(struct kobject *kobj,
 781                             struct kobj_attribute *attr, char *buff)
 782 {
 783         return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK);
 784 }
 785
 786 static struct kobj_attribute version_attr = __ATTR_RO(version);
 787
 788 static struct attribute *attributes[] = {
 789         &version_attr.attr,
 790         NULL,
 791 };
 792
 793 static struct attribute_group attr_group = {
 794         .attrs = attributes,
 795 };
 796
 797 static int do_sysfs_registration(void)
 798 {
 799         int rc;
 800
 801         ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj);
 802         if (!ecryptfs_kobj) {
 803                 printk(KERN_ERR "Unable to create ecryptfs kset\n");
 804                 rc = -ENOMEM;
 805                 goto out;
 806         }
 807         rc = sysfs_create_group(ecryptfs_kobj, &attr_group);
 808         if (rc) {
 809                 printk(KERN_ERR
 810                        "Unable to create ecryptfs version attributes\n");
 811                 kobject_put(ecryptfs_kobj);
 812         }
 813 out:
 814         return rc;
 815 }
 816
 817 static void do_sysfs_unregistration(void)
 818 {
 819         sysfs_remove_group(ecryptfs_kobj, &attr_group);
 820         kobject_put(ecryptfs_kobj);
 821 }
 822
 823 static int __init ecryptfs_init(void)
 824 {
 825         int rc;
 826
 827         if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_CACHE_SIZE) {
 828                 rc = -EINVAL;
 829                 ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is "
 830                                 "larger than the host's page size, and so "
 831                                 "eCryptfs cannot run on this system. The "
 832                                 "default eCryptfs extent size is [%u] bytes; "
 833                                 "the page size is [%lu] bytes.\n",
 834                                 ECRYPTFS_DEFAULT_EXTENT_SIZE,
 835                                 (unsigned long)PAGE_CACHE_SIZE);
 836                 goto out;
 837         }
 838         rc = ecryptfs_init_kmem_caches();
 839         if (rc) {
 840                 printk(KERN_ERR
 841                        "Failed to allocate one or more kmem_cache objects\n");
 842                 goto out;
 843         }
 844         rc = register_filesystem(&ecryptfs_fs_type);
 845         if (rc) {
 846                 printk(KERN_ERR "Failed to register filesystem\n");
 847                 goto out_free_kmem_caches;
 848         }
 849         rc = do_sysfs_registration();
 850         if (rc) {
 851                 printk(KERN_ERR "sysfs registration failed\n");
 852                 goto out_unregister_filesystem;
 853         }
 854         rc = ecryptfs_init_kthread();
 855         if (rc) {
 856                 printk(KERN_ERR "%s: kthread initialization failed; "
 857                        "rc = [%d]\n", __func__, rc);
 858                 goto out_do_sysfs_unregistration;
 859         }
 860         rc = ecryptfs_init_messaging();
 861         if (rc) {
 862                 printk(KERN_ERR "Failure occured while attempting to "
 863                                 "initialize the communications channel to "
 864                                 "ecryptfsd\n");
 865                 goto out_destroy_kthread;
 866         }
 867         rc = ecryptfs_init_crypto();
 868         if (rc) {
 869                 printk(KERN_ERR "Failure whilst attempting to init crypto; "
 870                        "rc = [%d]\n", rc);
 871                 goto out_release_messaging;
 872         }
 873         if (ecryptfs_verbosity > 0)
 874                 printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values "
 875                         "will be written to the syslog!\n", ecryptfs_verbosity);
 876
 877         goto out;
 878 out_release_messaging:
 879         ecryptfs_release_messaging();
 880 out_destroy_kthread:
 881         ecryptfs_destroy_kthread();
 882 out_do_sysfs_unregistration:
 883         do_sysfs_unregistration();
 884 out_unregister_filesystem:
 885         unregister_filesystem(&ecryptfs_fs_type);
 886 out_free_kmem_caches:
 887         ecryptfs_free_kmem_caches();
 888 out:
 889         return rc;
 890 }
 891
 892 static void __exit ecryptfs_exit(void)
 893 {
 894         int rc;
 895
 896         rc = ecryptfs_destroy_crypto();
 897         if (rc)
 898                 printk(KERN_ERR "Failure whilst attempting to destroy crypto; "
 899                        "rc = [%d]\n", rc);
 900         ecryptfs_release_messaging();
 901         ecryptfs_destroy_kthread();
 902         do_sysfs_unregistration();
 903         unregister_filesystem(&ecryptfs_fs_type);
 904         ecryptfs_free_kmem_caches();
 905 }
 906
 907 MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>");
 908 MODULE_DESCRIPTION("eCryptfs");
 909
 910 MODULE_LICENSE("GPL");
 911
 912 module_init(ecryptfs_init)
 913 module_exit(ecryptfs_exit)