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         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         return rc;
 141 }
 142
 143 static struct inode *ecryptfs_get_inode(struct inode *lower_inode,
 144                        struct super_block *sb)
 145 {
 146         struct inode *inode;
 147         int rc = 0;
 148
 149         if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb)) {
 150                 rc = -EXDEV;
 151                 goto out;
 152         }
 153         if (!igrab(lower_inode)) {
 154                 rc = -ESTALE;
 155                 goto out;
 156         }
 157         inode = iget5_locked(sb, (unsigned long)lower_inode,
 158                              ecryptfs_inode_test, ecryptfs_inode_set,
 159                              lower_inode);
 160         if (!inode) {
 161                 rc = -EACCES;
 162                 iput(lower_inode);
 163                 goto out;
 164         }
 165         if (inode->i_state & I_NEW)
 166                 unlock_new_inode(inode);
 167         else
 168                 iput(lower_inode);
 169         if (S_ISLNK(lower_inode->i_mode))
 170                 inode->i_op = &ecryptfs_symlink_iops;
 171         else if (S_ISDIR(lower_inode->i_mode))
 172                 inode->i_op = &ecryptfs_dir_iops;
 173         if (S_ISDIR(lower_inode->i_mode))
 174                 inode->i_fop = &ecryptfs_dir_fops;
 175         if (special_file(lower_inode->i_mode))
 176                 init_special_inode(inode, lower_inode->i_mode,
 177                                    lower_inode->i_rdev);
 178         fsstack_copy_attr_all(inode, lower_inode);
 179         /* This size will be overwritten for real files w/ headers and
 180          * other metadata */
 181         fsstack_copy_inode_size(inode, lower_inode);
 182         return inode;
 183 out:
 184         return ERR_PTR(rc);
 185 }
 186
 187 /**
 188  * ecryptfs_interpose
 189  * @lower_dentry: Existing dentry in the lower filesystem
 190  * @dentry: ecryptfs' dentry
 191  * @sb: ecryptfs's super_block
 192  * @flags: flags to govern behavior of interpose procedure
 193  *
 194  * Interposes upper and lower dentries.
 195  *
 196  * Returns zero on success; non-zero otherwise
 197  */
 198 int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry,
 199                        struct super_block *sb, u32 flags)
 200 {
 201         struct inode *lower_inode = lower_dentry->d_inode;
 202         struct inode *inode = ecryptfs_get_inode(lower_inode, sb);
 203         if (IS_ERR(inode))
 204                 return PTR_ERR(inode);
 205         if (flags & ECRYPTFS_INTERPOSE_FLAG_D_ADD)
 206                 d_add(dentry, inode);
 207         else
 208                 d_instantiate(dentry, inode);
 209         return 0;
 210 }
 211
 212 enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig,
 213        ecryptfs_opt_cipher, ecryptfs_opt_ecryptfs_cipher,
 214        ecryptfs_opt_ecryptfs_key_bytes,
 215        ecryptfs_opt_passthrough, ecryptfs_opt_xattr_metadata,
 216        ecryptfs_opt_encrypted_view, ecryptfs_opt_fnek_sig,
 217        ecryptfs_opt_fn_cipher, ecryptfs_opt_fn_cipher_key_bytes,
 218        ecryptfs_opt_unlink_sigs, ecryptfs_opt_mount_auth_tok_only,
 219        ecryptfs_opt_err };
 220
 221 static const 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_fnek_sig, "ecryptfs_fnek_sig=%s"},
 231         {ecryptfs_opt_fn_cipher, "ecryptfs_fn_cipher=%s"},
 232         {ecryptfs_opt_fn_cipher_key_bytes, "ecryptfs_fn_key_bytes=%u"},
 233         {ecryptfs_opt_unlink_sigs, "ecryptfs_unlink_sigs"},
 234         {ecryptfs_opt_mount_auth_tok_only, "ecryptfs_mount_auth_tok_only"},
 235         {ecryptfs_opt_err, NULL}
 236 };
 237
 238 static int ecryptfs_init_global_auth_toks(
 239         struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
 240 {
 241         struct ecryptfs_global_auth_tok *global_auth_tok;
 242         struct ecryptfs_auth_tok *auth_tok;
 243         int rc = 0;
 244
 245         list_for_each_entry(global_auth_tok,
 246                             &mount_crypt_stat->global_auth_tok_list,
 247                             mount_crypt_stat_list) {
 248                 rc = ecryptfs_keyring_auth_tok_for_sig(
 249                         &global_auth_tok->global_auth_tok_key, &auth_tok,
 250                         global_auth_tok->sig);
 251                 if (rc) {
 252                         printk(KERN_ERR "Could not find valid key in user "
 253                                "session keyring for sig specified in mount "
 254                                "option: [%s]\n", global_auth_tok->sig);
 255                         global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID;
 256                         goto out;
 257                 } else {
 258                         global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID;
 259                         up_write(&(global_auth_tok->global_auth_tok_key)->sem);
 260                 }
 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 passed 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         s->s_magic = ECRYPTFS_SUPER_MAGIC;
 569
 570         inode = ecryptfs_get_inode(path.dentry->d_inode, s);
 571         rc = PTR_ERR(inode);
 572         if (IS_ERR(inode))
 573                 goto out_free;
 574
 575         s->s_root = d_alloc_root(inode);
 576         if (!s->s_root) {
 577                 iput(inode);
 578                 rc = -ENOMEM;
 579                 goto out_free;
 580         }
 581
 582         rc = -ENOMEM;
 583         root_info = kmem_cache_zalloc(ecryptfs_dentry_info_cache, GFP_KERNEL);
 584         if (!root_info)
 585                 goto out_free;
 586
 587         /* ->kill_sb() will take care of root_info */
 588         ecryptfs_set_dentry_private(s->s_root, root_info);
 589         ecryptfs_set_dentry_lower(s->s_root, path.dentry);
 590         ecryptfs_set_dentry_lower_mnt(s->s_root, path.mnt);
 591
 592         s->s_flags |= MS_ACTIVE;
 593         return dget(s->s_root);
 594
 595 out_free:
 596         path_put(&path);
 597 out1:
 598         deactivate_locked_super(s);
 599 out:
 600         if (sbi) {
 601                 ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat);
 602                 kmem_cache_free(ecryptfs_sb_info_cache, sbi);
 603         }
 604         printk(KERN_ERR "%s; rc = [%d]\n", err, rc);
 605         return ERR_PTR(rc);
 606 }
 607
 608 /**
 609  * ecryptfs_kill_block_super
 610  * @sb: The ecryptfs super block
 611  *
 612  * Used to bring the superblock down and free the private data.
 613  */
 614 static void ecryptfs_kill_block_super(struct super_block *sb)
 615 {
 616         struct ecryptfs_sb_info *sb_info = ecryptfs_superblock_to_private(sb);
 617         kill_anon_super(sb);
 618         if (!sb_info)
 619                 return;
 620         ecryptfs_destroy_mount_crypt_stat(&sb_info->mount_crypt_stat);
 621         bdi_destroy(&sb_info->bdi);
 622         kmem_cache_free(ecryptfs_sb_info_cache, sb_info);
 623 }
 624
 625 static struct file_system_type ecryptfs_fs_type = {
 626         .owner = THIS_MODULE,
 627         .name = "ecryptfs",
 628         .mount = ecryptfs_mount,
 629         .kill_sb = ecryptfs_kill_block_super,
 630         .fs_flags = 0
 631 };
 632
 633 /**
 634  * inode_info_init_once
 635  *
 636  * Initializes the ecryptfs_inode_info_cache when it is created
 637  */
 638 static void
 639 inode_info_init_once(void *vptr)
 640 {
 641         struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr;
 642
 643         inode_init_once(&ei->vfs_inode);
 644 }
 645
 646 static struct ecryptfs_cache_info {
 647         struct kmem_cache **cache;
 648         const char *name;
 649         size_t size;
 650         void (*ctor)(void *obj);
 651 } ecryptfs_cache_infos[] = {
 652         {
 653                 .cache = &ecryptfs_auth_tok_list_item_cache,
 654                 .name = "ecryptfs_auth_tok_list_item",
 655                 .size = sizeof(struct ecryptfs_auth_tok_list_item),
 656         },
 657         {
 658                 .cache = &ecryptfs_file_info_cache,
 659                 .name = "ecryptfs_file_cache",
 660                 .size = sizeof(struct ecryptfs_file_info),
 661         },
 662         {
 663                 .cache = &ecryptfs_dentry_info_cache,
 664                 .name = "ecryptfs_dentry_info_cache",
 665                 .size = sizeof(struct ecryptfs_dentry_info),
 666         },
 667         {
 668                 .cache = &ecryptfs_inode_info_cache,
 669                 .name = "ecryptfs_inode_cache",
 670                 .size = sizeof(struct ecryptfs_inode_info),
 671                 .ctor = inode_info_init_once,
 672         },
 673         {
 674                 .cache = &ecryptfs_sb_info_cache,
 675                 .name = "ecryptfs_sb_cache",
 676                 .size = sizeof(struct ecryptfs_sb_info),
 677         },
 678         {
 679                 .cache = &ecryptfs_header_cache_1,
 680                 .name = "ecryptfs_headers_1",
 681                 .size = PAGE_CACHE_SIZE,
 682         },
 683         {
 684                 .cache = &ecryptfs_header_cache_2,
 685                 .name = "ecryptfs_headers_2",
 686                 .size = PAGE_CACHE_SIZE,
 687         },
 688         {
 689                 .cache = &ecryptfs_xattr_cache,
 690                 .name = "ecryptfs_xattr_cache",
 691                 .size = PAGE_CACHE_SIZE,
 692         },
 693         {
 694                 .cache = &ecryptfs_key_record_cache,
 695                 .name = "ecryptfs_key_record_cache",
 696                 .size = sizeof(struct ecryptfs_key_record),
 697         },
 698         {
 699                 .cache = &ecryptfs_key_sig_cache,
 700                 .name = "ecryptfs_key_sig_cache",
 701                 .size = sizeof(struct ecryptfs_key_sig),
 702         },
 703         {
 704                 .cache = &ecryptfs_global_auth_tok_cache,
 705                 .name = "ecryptfs_global_auth_tok_cache",
 706                 .size = sizeof(struct ecryptfs_global_auth_tok),
 707         },
 708         {
 709                 .cache = &ecryptfs_key_tfm_cache,
 710                 .name = "ecryptfs_key_tfm_cache",
 711                 .size = sizeof(struct ecryptfs_key_tfm),
 712         },
 713         {
 714                 .cache = &ecryptfs_open_req_cache,
 715                 .name = "ecryptfs_open_req_cache",
 716                 .size = sizeof(struct ecryptfs_open_req),
 717         },
 718 };
 719
 720 static void ecryptfs_free_kmem_caches(void)
 721 {
 722         int i;
 723
 724         for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
 725                 struct ecryptfs_cache_info *info;
 726
 727                 info = &ecryptfs_cache_infos[i];
 728                 if (*(info->cache))
 729                         kmem_cache_destroy(*(info->cache));
 730         }
 731 }
 732
 733 /**
 734  * ecryptfs_init_kmem_caches
 735  *
 736  * Returns zero on success; non-zero otherwise
 737  */
 738 static int ecryptfs_init_kmem_caches(void)
 739 {
 740         int i;
 741
 742         for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
 743                 struct ecryptfs_cache_info *info;
 744
 745                 info = &ecryptfs_cache_infos[i];
 746                 *(info->cache) = kmem_cache_create(info->name, info->size,
 747                                 0, SLAB_HWCACHE_ALIGN, info->ctor);
 748                 if (!*(info->cache)) {
 749                         ecryptfs_free_kmem_caches();
 750                         ecryptfs_printk(KERN_WARNING, "%s: "
 751                                         "kmem_cache_create failed\n",
 752                                         info->name);
 753                         return -ENOMEM;
 754                 }
 755         }
 756         return 0;
 757 }
 758
 759 static struct kobject *ecryptfs_kobj;
 760
 761 static ssize_t version_show(struct kobject *kobj,
 762                             struct kobj_attribute *attr, char *buff)
 763 {
 764         return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK);
 765 }
 766
 767 static struct kobj_attribute version_attr = __ATTR_RO(version);
 768
 769 static struct attribute *attributes[] = {
 770         &version_attr.attr,
 771         NULL,
 772 };
 773
 774 static struct attribute_group attr_group = {
 775         .attrs = attributes,
 776 };
 777
 778 static int do_sysfs_registration(void)
 779 {
 780         int rc;
 781
 782         ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj);
 783         if (!ecryptfs_kobj) {
 784                 printk(KERN_ERR "Unable to create ecryptfs kset\n");
 785                 rc = -ENOMEM;
 786                 goto out;
 787         }
 788         rc = sysfs_create_group(ecryptfs_kobj, &attr_group);
 789         if (rc) {
 790                 printk(KERN_ERR
 791                        "Unable to create ecryptfs version attributes\n");
 792                 kobject_put(ecryptfs_kobj);
 793         }
 794 out:
 795         return rc;
 796 }
 797
 798 static void do_sysfs_unregistration(void)
 799 {
 800         sysfs_remove_group(ecryptfs_kobj, &attr_group);
 801         kobject_put(ecryptfs_kobj);
 802 }
 803
 804 static int __init ecryptfs_init(void)
 805 {
 806         int rc;
 807
 808         if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_CACHE_SIZE) {
 809                 rc = -EINVAL;
 810                 ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is "
 811                                 "larger than the host's page size, and so "
 812                                 "eCryptfs cannot run on this system. The "
 813                                 "default eCryptfs extent size is [%u] bytes; "
 814                                 "the page size is [%lu] bytes.\n",
 815                                 ECRYPTFS_DEFAULT_EXTENT_SIZE,
 816                                 (unsigned long)PAGE_CACHE_SIZE);
 817                 goto out;
 818         }
 819         rc = ecryptfs_init_kmem_caches();
 820         if (rc) {
 821                 printk(KERN_ERR
 822                        "Failed to allocate one or more kmem_cache objects\n");
 823                 goto out;
 824         }
 825         rc = register_filesystem(&ecryptfs_fs_type);
 826         if (rc) {
 827                 printk(KERN_ERR "Failed to register filesystem\n");
 828                 goto out_free_kmem_caches;
 829         }
 830         rc = do_sysfs_registration();
 831         if (rc) {
 832                 printk(KERN_ERR "sysfs registration failed\n");
 833                 goto out_unregister_filesystem;
 834         }
 835         rc = ecryptfs_init_kthread();
 836         if (rc) {
 837                 printk(KERN_ERR "%s: kthread initialization failed; "
 838                        "rc = [%d]\n", __func__, rc);
 839                 goto out_do_sysfs_unregistration;
 840         }
 841         rc = ecryptfs_init_messaging();
 842         if (rc) {
 843                 printk(KERN_ERR "Failure occurred while attempting to "
 844                                 "initialize the communications channel to "
 845                                 "ecryptfsd\n");
 846                 goto out_destroy_kthread;
 847         }
 848         rc = ecryptfs_init_crypto();
 849         if (rc) {
 850                 printk(KERN_ERR "Failure whilst attempting to init crypto; "
 851                        "rc = [%d]\n", rc);
 852                 goto out_release_messaging;
 853         }
 854         if (ecryptfs_verbosity > 0)
 855                 printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values "
 856                         "will be written to the syslog!\n", ecryptfs_verbosity);
 857
 858         goto out;
 859 out_release_messaging:
 860         ecryptfs_release_messaging();
 861 out_destroy_kthread:
 862         ecryptfs_destroy_kthread();
 863 out_do_sysfs_unregistration:
 864         do_sysfs_unregistration();
 865 out_unregister_filesystem:
 866         unregister_filesystem(&ecryptfs_fs_type);
 867 out_free_kmem_caches:
 868         ecryptfs_free_kmem_caches();
 869 out:
 870         return rc;
 871 }
 872
 873 static void __exit ecryptfs_exit(void)
 874 {
 875         int rc;
 876
 877         rc = ecryptfs_destroy_crypto();
 878         if (rc)
 879                 printk(KERN_ERR "Failure whilst attempting to destroy crypto; "
 880                        "rc = [%d]\n", rc);
 881         ecryptfs_release_messaging();
 882         ecryptfs_destroy_kthread();
 883         do_sysfs_unregistration();
 884         unregister_filesystem(&ecryptfs_fs_type);
 885         ecryptfs_free_kmem_caches();
 886 }
 887
 888 MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>");
 889 MODULE_DESCRIPTION("eCryptfs");
 890
 891 MODULE_LICENSE("GPL");
 892
 893 module_init(ecryptfs_init)
 894 module_exit(ecryptfs_exit)