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 "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 message buffer elements
  53  */
  54 unsigned int ecryptfs_message_buf_len = ECRYPTFS_DEFAULT_MSG_CTX_ELEMS;
  55
  56 module_param(ecryptfs_message_buf_len, uint, 0);
  57 MODULE_PARM_DESC(ecryptfs_message_buf_len,
  58                  "Number of message buffer elements");
  59
  60 /**
  61  * Module parameter that defines the maximum guaranteed amount of time to wait
  62  * for a response from ecryptfsd.  The actual sleep time will be, more than
  63  * likely, a small amount greater than this specified value, but only less if
  64  * the message successfully arrives.
  65  */
  66 signed long ecryptfs_message_wait_timeout = ECRYPTFS_MAX_MSG_CTX_TTL / HZ;
  67
  68 module_param(ecryptfs_message_wait_timeout, long, 0);
  69 MODULE_PARM_DESC(ecryptfs_message_wait_timeout,
  70                  "Maximum number of seconds that an operation will "
  71                  "sleep while waiting for a message response from "
  72                  "userspace");
  73
  74 /**
  75  * Module parameter that is an estimate of the maximum number of users
  76  * that will be concurrently using eCryptfs. Set this to the right
  77  * value to balance performance and memory use.
  78  */
  79 unsigned int ecryptfs_number_of_users = ECRYPTFS_DEFAULT_NUM_USERS;
  80
  81 module_param(ecryptfs_number_of_users, uint, 0);
  82 MODULE_PARM_DESC(ecryptfs_number_of_users, "An estimate of the number of "
  83                  "concurrent users of eCryptfs");
  84
  85 void __ecryptfs_printk(const char *fmt, ...)
  86 {
  87         va_list args;
  88         va_start(args, fmt);
  89         if (fmt[1] == '7') { /* KERN_DEBUG */
  90                 if (ecryptfs_verbosity >= 1)
  91                         vprintk(fmt, args);
  92         } else
  93                 vprintk(fmt, args);
  94         va_end(args);
  95 }
  96
  97 /**
  98  * ecryptfs_init_persistent_file
  99  * @ecryptfs_dentry: Fully initialized eCryptfs dentry object, with
 100  *                   the lower dentry and the lower mount set
 101  *
 102  * eCryptfs only ever keeps a single open file for every lower
 103  * inode. All I/O operations to the lower inode occur through that
 104  * file. When the first eCryptfs dentry that interposes with the first
 105  * lower dentry for that inode is created, this function creates the
 106  * persistent file struct and associates it with the eCryptfs
 107  * inode. When the eCryptfs inode is destroyed, the file is closed.
 108  *
 109  * The persistent file will be opened with read/write permissions, if
 110  * possible. Otherwise, it is opened read-only.
 111  *
 112  * This function does nothing if a lower persistent file is already
 113  * associated with the eCryptfs inode.
 114  *
 115  * Returns zero on success; non-zero otherwise
 116  */
 117 int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry)
 118 {
 119         const struct cred *cred = current_cred();
 120         struct ecryptfs_inode_info *inode_info =
 121                 ecryptfs_inode_to_private(ecryptfs_dentry->d_inode);
 122         int rc = 0;
 123
 124         mutex_lock(&inode_info->lower_file_mutex);
 125         if (!inode_info->lower_file) {
 126                 struct dentry *lower_dentry;
 127                 struct vfsmount *lower_mnt =
 128                         ecryptfs_dentry_to_lower_mnt(ecryptfs_dentry);
 129
 130                 lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
 131                 rc = ecryptfs_privileged_open(&inode_info->lower_file,
 132                                               lower_dentry, lower_mnt, cred);
 133                 if (rc) {
 134                         printk(KERN_ERR "Error opening lower persistent file "
 135                                "for lower_dentry [0x%p] and lower_mnt [0x%p]; "
 136                                "rc = [%d]\n", lower_dentry, lower_mnt, rc);
 137                         inode_info->lower_file = NULL;
 138                 }
 139         }
 140         mutex_unlock(&inode_info->lower_file_mutex);
 141         return rc;
 142 }
 143
 144 static inode *ecryptfs_get_inode(struct inode *lower_inode,
 145                        struct super_block *sb)
 146 {
 147         struct inode *inode;
 148         int rc = 0;
 149
 150         lower_inode = lower_dentry->d_inode;
 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_err };
 222
 223 static const match_table_t tokens = {
 224         {ecryptfs_opt_sig, "sig=%s"},
 225         {ecryptfs_opt_ecryptfs_sig, "ecryptfs_sig=%s"},
 226         {ecryptfs_opt_cipher, "cipher=%s"},
 227         {ecryptfs_opt_ecryptfs_cipher, "ecryptfs_cipher=%s"},
 228         {ecryptfs_opt_ecryptfs_key_bytes, "ecryptfs_key_bytes=%u"},
 229         {ecryptfs_opt_passthrough, "ecryptfs_passthrough"},
 230         {ecryptfs_opt_xattr_metadata, "ecryptfs_xattr_metadata"},
 231         {ecryptfs_opt_encrypted_view, "ecryptfs_encrypted_view"},
 232         {ecryptfs_opt_fnek_sig, "ecryptfs_fnek_sig=%s"},
 233         {ecryptfs_opt_fn_cipher, "ecryptfs_fn_cipher=%s"},
 234         {ecryptfs_opt_fn_cipher_key_bytes, "ecryptfs_fn_key_bytes=%u"},
 235         {ecryptfs_opt_unlink_sigs, "ecryptfs_unlink_sigs"},
 236         {ecryptfs_opt_mount_auth_tok_only, "ecryptfs_mount_auth_tok_only"},
 237         {ecryptfs_opt_err, NULL}
 238 };
 239
 240 static int ecryptfs_init_global_auth_toks(
 241         struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
 242 {
 243         struct ecryptfs_global_auth_tok *global_auth_tok;
 244         int rc = 0;
 245
 246         list_for_each_entry(global_auth_tok,
 247                             &mount_crypt_stat->global_auth_tok_list,
 248                             mount_crypt_stat_list) {
 249                 rc = ecryptfs_keyring_auth_tok_for_sig(
 250                         &global_auth_tok->global_auth_tok_key,
 251                         &global_auth_tok->global_auth_tok,
 252                         global_auth_tok->sig);
 253                 if (rc) {
 254                         printk(KERN_ERR "Could not find valid key in user "
 255                                "session keyring for sig specified in mount "
 256                                "option: [%s]\n", global_auth_tok->sig);
 257                         global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID;
 258                         goto out;
 259                 } else
 260                         global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID;
 261         }
 262 out:
 263         return rc;
 264 }
 265
 266 static void ecryptfs_init_mount_crypt_stat(
 267         struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
 268 {
 269         memset((void *)mount_crypt_stat, 0,
 270                sizeof(struct ecryptfs_mount_crypt_stat));
 271         INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list);
 272         mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex);
 273         mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED;
 274 }
 275
 276 /**
 277  * ecryptfs_parse_options
 278  * @sb: The ecryptfs super block
 279  * @options: The options pased to the kernel
 280  *
 281  * Parse mount options:
 282  * debug=N         - ecryptfs_verbosity level for debug output
 283  * sig=XXX         - description(signature) of the key to use
 284  *
 285  * Returns the dentry object of the lower-level (lower/interposed)
 286  * directory; We want to mount our stackable file system on top of
 287  * that lower directory.
 288  *
 289  * The signature of the key to use must be the description of a key
 290  * already in the keyring. Mounting will fail if the key can not be
 291  * found.
 292  *
 293  * Returns zero on success; non-zero on error
 294  */
 295 static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options)
 296 {
 297         char *p;
 298         int rc = 0;
 299         int sig_set = 0;
 300         int cipher_name_set = 0;
 301         int fn_cipher_name_set = 0;
 302         int cipher_key_bytes;
 303         int cipher_key_bytes_set = 0;
 304         int fn_cipher_key_bytes;
 305         int fn_cipher_key_bytes_set = 0;
 306         struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
 307                 &sbi->mount_crypt_stat;
 308         substring_t args[MAX_OPT_ARGS];
 309         int token;
 310         char *sig_src;
 311         char *cipher_name_dst;
 312         char *cipher_name_src;
 313         char *fn_cipher_name_dst;
 314         char *fn_cipher_name_src;
 315         char *fnek_dst;
 316         char *fnek_src;
 317         char *cipher_key_bytes_src;
 318         char *fn_cipher_key_bytes_src;
 319
 320         if (!options) {
 321                 rc = -EINVAL;
 322                 goto out;
 323         }
 324         ecryptfs_init_mount_crypt_stat(mount_crypt_stat);
 325         while ((p = strsep(&options, ",")) != NULL) {
 326                 if (!*p)
 327                         continue;
 328                 token = match_token(p, tokens, args);
 329                 switch (token) {
 330                 case ecryptfs_opt_sig:
 331                 case ecryptfs_opt_ecryptfs_sig:
 332                         sig_src = args[0].from;
 333                         rc = ecryptfs_add_global_auth_tok(mount_crypt_stat,
 334                                                           sig_src, 0);
 335                         if (rc) {
 336                                 printk(KERN_ERR "Error attempting to register "
 337                                        "global sig; rc = [%d]\n", rc);
 338                                 goto out;
 339                         }
 340                         sig_set = 1;
 341                         break;
 342                 case ecryptfs_opt_cipher:
 343                 case ecryptfs_opt_ecryptfs_cipher:
 344                         cipher_name_src = args[0].from;
 345                         cipher_name_dst =
 346                                 mount_crypt_stat->
 347                                 global_default_cipher_name;
 348                         strncpy(cipher_name_dst, cipher_name_src,
 349                                 ECRYPTFS_MAX_CIPHER_NAME_SIZE);
 350                         cipher_name_dst[ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0';
 351                         cipher_name_set = 1;
 352                         break;
 353                 case ecryptfs_opt_ecryptfs_key_bytes:
 354                         cipher_key_bytes_src = args[0].from;
 355                         cipher_key_bytes =
 356                                 (int)simple_strtol(cipher_key_bytes_src,
 357                                                    &cipher_key_bytes_src, 0);
 358                         mount_crypt_stat->global_default_cipher_key_size =
 359                                 cipher_key_bytes;
 360                         cipher_key_bytes_set = 1;
 361                         break;
 362                 case ecryptfs_opt_passthrough:
 363                         mount_crypt_stat->flags |=
 364                                 ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED;
 365                         break;
 366                 case ecryptfs_opt_xattr_metadata:
 367                         mount_crypt_stat->flags |=
 368                                 ECRYPTFS_XATTR_METADATA_ENABLED;
 369                         break;
 370                 case ecryptfs_opt_encrypted_view:
 371                         mount_crypt_stat->flags |=
 372                                 ECRYPTFS_XATTR_METADATA_ENABLED;
 373                         mount_crypt_stat->flags |=
 374                                 ECRYPTFS_ENCRYPTED_VIEW_ENABLED;
 375                         break;
 376                 case ecryptfs_opt_fnek_sig:
 377                         fnek_src = args[0].from;
 378                         fnek_dst =
 379                                 mount_crypt_stat->global_default_fnek_sig;
 380                         strncpy(fnek_dst, fnek_src, ECRYPTFS_SIG_SIZE_HEX);
 381                         mount_crypt_stat->global_default_fnek_sig[
 382                                 ECRYPTFS_SIG_SIZE_HEX] = '\0';
 383                         rc = ecryptfs_add_global_auth_tok(
 384                                 mount_crypt_stat,
 385                                 mount_crypt_stat->global_default_fnek_sig,
 386                                 ECRYPTFS_AUTH_TOK_FNEK);
 387                         if (rc) {
 388                                 printk(KERN_ERR "Error attempting to register "
 389                                        "global fnek sig [%s]; rc = [%d]\n",
 390                                        mount_crypt_stat->global_default_fnek_sig,
 391                                        rc);
 392                                 goto out;
 393                         }
 394                         mount_crypt_stat->flags |=
 395                                 (ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
 396                                  | ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK);
 397                         break;
 398                 case ecryptfs_opt_fn_cipher:
 399                         fn_cipher_name_src = args[0].from;
 400                         fn_cipher_name_dst =
 401                                 mount_crypt_stat->global_default_fn_cipher_name;
 402                         strncpy(fn_cipher_name_dst, fn_cipher_name_src,
 403                                 ECRYPTFS_MAX_CIPHER_NAME_SIZE);
 404                         mount_crypt_stat->global_default_fn_cipher_name[
 405                                 ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0';
 406                         fn_cipher_name_set = 1;
 407                         break;
 408                 case ecryptfs_opt_fn_cipher_key_bytes:
 409                         fn_cipher_key_bytes_src = args[0].from;
 410                         fn_cipher_key_bytes =
 411                                 (int)simple_strtol(fn_cipher_key_bytes_src,
 412                                                    &fn_cipher_key_bytes_src, 0);
 413                         mount_crypt_stat->global_default_fn_cipher_key_bytes =
 414                                 fn_cipher_key_bytes;
 415                         fn_cipher_key_bytes_set = 1;
 416                         break;
 417                 case ecryptfs_opt_unlink_sigs:
 418                         mount_crypt_stat->flags |= ECRYPTFS_UNLINK_SIGS;
 419                         break;
 420                 case ecryptfs_opt_mount_auth_tok_only:
 421                         mount_crypt_stat->flags |=
 422                                 ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY;
 423                         break;
 424                 case ecryptfs_opt_err:
 425                 default:
 426                         printk(KERN_WARNING
 427                                "%s: eCryptfs: unrecognized option [%s]\n",
 428                                __func__, p);
 429                 }
 430         }
 431         if (!sig_set) {
 432                 rc = -EINVAL;
 433                 ecryptfs_printk(KERN_ERR, "You must supply at least one valid "
 434                                 "auth tok signature as a mount "
 435                                 "parameter; see the eCryptfs README\n");
 436                 goto out;
 437         }
 438         if (!cipher_name_set) {
 439                 int cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER);
 440
 441                 BUG_ON(cipher_name_len >= ECRYPTFS_MAX_CIPHER_NAME_SIZE);
 442                 strcpy(mount_crypt_stat->global_default_cipher_name,
 443                        ECRYPTFS_DEFAULT_CIPHER);
 444         }
 445         if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
 446             && !fn_cipher_name_set)
 447                 strcpy(mount_crypt_stat->global_default_fn_cipher_name,
 448                        mount_crypt_stat->global_default_cipher_name);
 449         if (!cipher_key_bytes_set)
 450                 mount_crypt_stat->global_default_cipher_key_size = 0;
 451         if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
 452             && !fn_cipher_key_bytes_set)
 453                 mount_crypt_stat->global_default_fn_cipher_key_bytes =
 454                         mount_crypt_stat->global_default_cipher_key_size;
 455         mutex_lock(&key_tfm_list_mutex);
 456         if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name,
 457                                  NULL)) {
 458                 rc = ecryptfs_add_new_key_tfm(
 459                         NULL, mount_crypt_stat->global_default_cipher_name,
 460                         mount_crypt_stat->global_default_cipher_key_size);
 461                 if (rc) {
 462                         printk(KERN_ERR "Error attempting to initialize "
 463                                "cipher with name = [%s] and key size = [%td]; "
 464                                "rc = [%d]\n",
 465                                mount_crypt_stat->global_default_cipher_name,
 466                                mount_crypt_stat->global_default_cipher_key_size,
 467                                rc);
 468                         rc = -EINVAL;
 469                         mutex_unlock(&key_tfm_list_mutex);
 470                         goto out;
 471                 }
 472         }
 473         if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
 474             && !ecryptfs_tfm_exists(
 475                     mount_crypt_stat->global_default_fn_cipher_name, NULL)) {
 476                 rc = ecryptfs_add_new_key_tfm(
 477                         NULL, mount_crypt_stat->global_default_fn_cipher_name,
 478                         mount_crypt_stat->global_default_fn_cipher_key_bytes);
 479                 if (rc) {
 480                         printk(KERN_ERR "Error attempting to initialize "
 481                                "cipher with name = [%s] and key size = [%td]; "
 482                                "rc = [%d]\n",
 483                                mount_crypt_stat->global_default_fn_cipher_name,
 484                                mount_crypt_stat->global_default_fn_cipher_key_bytes,
 485                                rc);
 486                         rc = -EINVAL;
 487                         mutex_unlock(&key_tfm_list_mutex);
 488                         goto out;
 489                 }
 490         }
 491         mutex_unlock(&key_tfm_list_mutex);
 492         rc = ecryptfs_init_global_auth_toks(mount_crypt_stat);
 493         if (rc)
 494                 printk(KERN_WARNING "One or more global auth toks could not "
 495                        "properly register; rc = [%d]\n", rc);
 496 out:
 497         return rc;
 498 }
 499
 500 struct kmem_cache *ecryptfs_sb_info_cache;
 501 static struct file_system_type ecryptfs_fs_type;
 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 static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags,
 511                         const char *dev_name, void *raw_data)
 512 {
 513         struct super_block *s;
 514         struct ecryptfs_sb_info *sbi;
 515         struct ecryptfs_dentry_info *root_info;
 516         const char *err = "Getting sb failed";
 517         struct inode *inode;
 518         struct path path;
 519         int rc;
 520
 521         sbi = kmem_cache_zalloc(ecryptfs_sb_info_cache, GFP_KERNEL);
 522         if (!sbi) {
 523                 rc = -ENOMEM;
 524                 goto out;
 525         }
 526
 527         rc = ecryptfs_parse_options(sbi, raw_data);
 528         if (rc) {
 529                 err = "Error parsing options";
 530                 goto out;
 531         }
 532
 533         s = sget(fs_type, NULL, set_anon_super, NULL);
 534         if (IS_ERR(s)) {
 535                 rc = PTR_ERR(s);
 536                 goto out;
 537         }
 538
 539         s->s_flags = flags;
 540         rc = bdi_setup_and_register(&sbi->bdi, "ecryptfs", BDI_CAP_MAP_COPY);
 541         if (rc)
 542                 goto out1;
 543
 544         ecryptfs_set_superblock_private(s, sbi);
 545         s->s_bdi = &sbi->bdi;
 546
 547         /* ->kill_sb() will take care of sbi after that point */
 548         sbi = NULL;
 549         s->s_op = &ecryptfs_sops;
 550         s->s_d_op = &ecryptfs_dops;
 551
 552         err = "Reading sb failed";
 553         rc = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path);
 554         if (rc) {
 555                 ecryptfs_printk(KERN_WARNING, "kern_path() failed\n");
 556                 goto out1;
 557         }
 558         if (path.dentry->d_sb->s_type == &ecryptfs_fs_type) {
 559                 rc = -EINVAL;
 560                 printk(KERN_ERR "Mount on filesystem of type "
 561                         "eCryptfs explicitly disallowed due to "
 562                         "known incompatibilities\n");
 563                 goto out_free;
 564         }
 565         ecryptfs_set_superblock_lower(s, path.dentry->d_sb);
 566         s->s_maxbytes = path.dentry->d_sb->s_maxbytes;
 567         s->s_blocksize = path.dentry->d_sb->s_blocksize;
 568
 569         inode = ecryptfs_get_inode(path.dentry->d_inode, s);
 570         rc = PTR_ERR(inode);
 571         if (IS_ERR(inode))
 572                 goto out_free;
 573
 574         s->s_root = d_alloc_root(inode);
 575         if (!s->s_root) {
 576                 iput(inode);
 577                 rc = -ENOMEM;
 578                 goto out_free;
 579         }
 580
 581         rc = -ENOMEM;
 582         root_info = kmem_cache_zalloc(ecryptfs_dentry_info_cache, GFP_KERNEL);
 583         if (!root_info)
 584                 goto out_free;
 585
 586         /* ->kill_sb() will take care of root_info */
 587         ecryptfs_set_dentry_private(s->s_root, root_info);
 588         ecryptfs_set_dentry_lower(s->s_root, path.dentry);
 589         ecryptfs_set_dentry_lower_mnt(s->s_root, path.mnt);
 590
 591         s->s_flags |= MS_ACTIVE;
 592         return dget(s->s_root);
 593
 594 out_free:
 595         path_put(&path);
 596 out1:
 597         deactivate_locked_super(s);
 598 out:
 599         if (sbi) {
 600                 ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat);
 601                 kmem_cache_free(ecryptfs_sb_info_cache, sbi);
 602         }
 603         printk(KERN_ERR "%s; rc = [%d]\n", err, rc);
 604         return ERR_PTR(rc);
 605 }
 606
 607 /**
 608  * ecryptfs_kill_block_super
 609  * @sb: The ecryptfs super block
 610  *
 611  * Used to bring the superblock down and free the private data.
 612  */
 613 static void ecryptfs_kill_block_super(struct super_block *sb)
 614 {
 615         struct ecryptfs_sb_info *sb_info = ecryptfs_superblock_to_private(sb);
 616         kill_anon_super(sb);
 617         if (!sb_info)
 618                 return;
 619         ecryptfs_destroy_mount_crypt_stat(&sb_info->mount_crypt_stat);
 620         bdi_destroy(&sb_info->bdi);
 621         kmem_cache_free(ecryptfs_sb_info_cache, sb_info);
 622 }
 623
 624 static struct file_system_type ecryptfs_fs_type = {
 625         .owner = THIS_MODULE,
 626         .name = "ecryptfs",
 627         .mount = ecryptfs_mount,
 628         .kill_sb = ecryptfs_kill_block_super,
 629         .fs_flags = 0
 630 };
 631
 632 /**
 633  * inode_info_init_once
 634  *
 635  * Initializes the ecryptfs_inode_info_cache when it is created
 636  */
 637 static void
 638 inode_info_init_once(void *vptr)
 639 {
 640         struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr;
 641
 642         inode_init_once(&ei->vfs_inode);
 643 }
 644
 645 static struct ecryptfs_cache_info {
 646         struct kmem_cache **cache;
 647         const char *name;
 648         size_t size;
 649         void (*ctor)(void *obj);
 650 } ecryptfs_cache_infos[] = {
 651         {
 652                 .cache = &ecryptfs_auth_tok_list_item_cache,
 653                 .name = "ecryptfs_auth_tok_list_item",
 654                 .size = sizeof(struct ecryptfs_auth_tok_list_item),
 655         },
 656         {
 657                 .cache = &ecryptfs_file_info_cache,
 658                 .name = "ecryptfs_file_cache",
 659                 .size = sizeof(struct ecryptfs_file_info),
 660         },
 661         {
 662                 .cache = &ecryptfs_dentry_info_cache,
 663                 .name = "ecryptfs_dentry_info_cache",
 664                 .size = sizeof(struct ecryptfs_dentry_info),
 665         },
 666         {
 667                 .cache = &ecryptfs_inode_info_cache,
 668                 .name = "ecryptfs_inode_cache",
 669                 .size = sizeof(struct ecryptfs_inode_info),
 670                 .ctor = inode_info_init_once,
 671         },
 672         {
 673                 .cache = &ecryptfs_sb_info_cache,
 674                 .name = "ecryptfs_sb_cache",
 675                 .size = sizeof(struct ecryptfs_sb_info),
 676         },
 677         {
 678                 .cache = &ecryptfs_header_cache_1,
 679                 .name = "ecryptfs_headers_1",
 680                 .size = PAGE_CACHE_SIZE,
 681         },
 682         {
 683                 .cache = &ecryptfs_header_cache_2,
 684                 .name = "ecryptfs_headers_2",
 685                 .size = PAGE_CACHE_SIZE,
 686         },
 687         {
 688                 .cache = &ecryptfs_xattr_cache,
 689                 .name = "ecryptfs_xattr_cache",
 690                 .size = PAGE_CACHE_SIZE,
 691         },
 692         {
 693                 .cache = &ecryptfs_key_record_cache,
 694                 .name = "ecryptfs_key_record_cache",
 695                 .size = sizeof(struct ecryptfs_key_record),
 696         },
 697         {
 698                 .cache = &ecryptfs_key_sig_cache,
 699                 .name = "ecryptfs_key_sig_cache",
 700                 .size = sizeof(struct ecryptfs_key_sig),
 701         },
 702         {
 703                 .cache = &ecryptfs_global_auth_tok_cache,
 704                 .name = "ecryptfs_global_auth_tok_cache",
 705                 .size = sizeof(struct ecryptfs_global_auth_tok),
 706         },
 707         {
 708                 .cache = &ecryptfs_key_tfm_cache,
 709                 .name = "ecryptfs_key_tfm_cache",
 710                 .size = sizeof(struct ecryptfs_key_tfm),
 711         },
 712         {
 713                 .cache = &ecryptfs_open_req_cache,
 714                 .name = "ecryptfs_open_req_cache",
 715                 .size = sizeof(struct ecryptfs_open_req),
 716         },
 717 };
 718
 719 static void ecryptfs_free_kmem_caches(void)
 720 {
 721         int i;
 722
 723         for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
 724                 struct ecryptfs_cache_info *info;
 725
 726                 info = &ecryptfs_cache_infos[i];
 727                 if (*(info->cache))
 728                         kmem_cache_destroy(*(info->cache));
 729         }
 730 }
 731
 732 /**
 733  * ecryptfs_init_kmem_caches
 734  *
 735  * Returns zero on success; non-zero otherwise
 736  */
 737 static int ecryptfs_init_kmem_caches(void)
 738 {
 739         int i;
 740
 741         for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
 742                 struct ecryptfs_cache_info *info;
 743
 744                 info = &ecryptfs_cache_infos[i];
 745                 *(info->cache) = kmem_cache_create(info->name, info->size,
 746                                 0, SLAB_HWCACHE_ALIGN, info->ctor);
 747                 if (!*(info->cache)) {
 748                         ecryptfs_free_kmem_caches();
 749                         ecryptfs_printk(KERN_WARNING, "%s: "
 750                                         "kmem_cache_create failed\n",
 751                                         info->name);
 752                         return -ENOMEM;
 753                 }
 754         }
 755         return 0;
 756 }
 757
 758 static struct kobject *ecryptfs_kobj;
 759
 760 static ssize_t version_show(struct kobject *kobj,
 761                             struct kobj_attribute *attr, char *buff)
 762 {
 763         return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK);
 764 }
 765
 766 static struct kobj_attribute version_attr = __ATTR_RO(version);
 767
 768 static struct attribute *attributes[] = {
 769         &version_attr.attr,
 770         NULL,
 771 };
 772
 773 static struct attribute_group attr_group = {
 774         .attrs = attributes,
 775 };
 776
 777 static int do_sysfs_registration(void)
 778 {
 779         int rc;
 780
 781         ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj);
 782         if (!ecryptfs_kobj) {
 783                 printk(KERN_ERR "Unable to create ecryptfs kset\n");
 784                 rc = -ENOMEM;
 785                 goto out;
 786         }
 787         rc = sysfs_create_group(ecryptfs_kobj, &attr_group);
 788         if (rc) {
 789                 printk(KERN_ERR
 790                        "Unable to create ecryptfs version attributes\n");
 791                 kobject_put(ecryptfs_kobj);
 792         }
 793 out:
 794         return rc;
 795 }
 796
 797 static void do_sysfs_unregistration(void)
 798 {
 799         sysfs_remove_group(ecryptfs_kobj, &attr_group);
 800         kobject_put(ecryptfs_kobj);
 801 }
 802
 803 static int __init ecryptfs_init(void)
 804 {
 805         int rc;
 806
 807         if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_CACHE_SIZE) {
 808                 rc = -EINVAL;
 809                 ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is "
 810                                 "larger than the host's page size, and so "
 811                                 "eCryptfs cannot run on this system. The "
 812                                 "default eCryptfs extent size is [%d] bytes; "
 813                                 "the page size is [%d] bytes.\n",
 814                                 ECRYPTFS_DEFAULT_EXTENT_SIZE, PAGE_CACHE_SIZE);
 815                 goto out;
 816         }
 817         rc = ecryptfs_init_kmem_caches();
 818         if (rc) {
 819                 printk(KERN_ERR
 820                        "Failed to allocate one or more kmem_cache objects\n");
 821                 goto out;
 822         }
 823         rc = register_filesystem(&ecryptfs_fs_type);
 824         if (rc) {
 825                 printk(KERN_ERR "Failed to register filesystem\n");
 826                 goto out_free_kmem_caches;
 827         }
 828         rc = do_sysfs_registration();
 829         if (rc) {
 830                 printk(KERN_ERR "sysfs registration failed\n");
 831                 goto out_unregister_filesystem;
 832         }
 833         rc = ecryptfs_init_kthread();
 834         if (rc) {
 835                 printk(KERN_ERR "%s: kthread initialization failed; "
 836                        "rc = [%d]\n", __func__, rc);
 837                 goto out_do_sysfs_unregistration;
 838         }
 839         rc = ecryptfs_init_messaging();
 840         if (rc) {
 841                 printk(KERN_ERR "Failure occured while attempting to "
 842                                 "initialize the communications channel to "
 843                                 "ecryptfsd\n");
 844                 goto out_destroy_kthread;
 845         }
 846         rc = ecryptfs_init_crypto();
 847         if (rc) {
 848                 printk(KERN_ERR "Failure whilst attempting to init crypto; "
 849                        "rc = [%d]\n", rc);
 850                 goto out_release_messaging;
 851         }
 852         if (ecryptfs_verbosity > 0)
 853                 printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values "
 854                         "will be written to the syslog!\n", ecryptfs_verbosity);
 855
 856         goto out;
 857 out_release_messaging:
 858         ecryptfs_release_messaging();
 859 out_destroy_kthread:
 860         ecryptfs_destroy_kthread();
 861 out_do_sysfs_unregistration:
 862         do_sysfs_unregistration();
 863 out_unregister_filesystem:
 864         unregister_filesystem(&ecryptfs_fs_type);
 865 out_free_kmem_caches:
 866         ecryptfs_free_kmem_caches();
 867 out:
 868         return rc;
 869 }
 870
 871 static void __exit ecryptfs_exit(void)
 872 {
 873         int rc;
 874
 875         rc = ecryptfs_destroy_crypto();
 876         if (rc)
 877                 printk(KERN_ERR "Failure whilst attempting to destroy crypto; "
 878                        "rc = [%d]\n", rc);
 879         ecryptfs_release_messaging();
 880         ecryptfs_destroy_kthread();
 881         do_sysfs_unregistration();
 882         unregister_filesystem(&ecryptfs_fs_type);
 883         ecryptfs_free_kmem_caches();
 884 }
 885
 886 MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>");
 887 MODULE_DESCRIPTION("eCryptfs");
 888
 889 MODULE_LICENSE("GPL");
 890
 891 module_init(ecryptfs_init)
 892 module_exit(ecryptfs_exit)