Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

1 files changed, 828 insertions, 0 deletions

diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c
new file mode 100644
index 00000000000..5938a232d11
--- /dev/null
+++ b/fs/ecryptfs/main.c
@@ -0,0 +1,828 @@
+/**
+ * eCryptfs: Linux filesystem encryption layer
+ *
+ * Copyright (C) 1997-2003 Erez Zadok
+ * Copyright (C) 2001-2003 Stony Brook University
+ * Copyright (C) 2004-2006 International Business Machines Corp.
+ *   Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
+ *              Michael C. Thompson <mcthomps@us.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ */
+
+#include <linux/dcache.h>
+#include <linux/file.h>
+#include <linux/module.h>
+#include <linux/namei.h>
+#include <linux/skbuff.h>
+#include <linux/crypto.h>
+#include <linux/netlink.h>
+#include <linux/mount.h>
+#include <linux/dcache.h>
+#include <linux/pagemap.h>
+#include <linux/key.h>
+#include <linux/parser.h>
+#include "ecryptfs_kernel.h"
+
+/**
+ * Module parameter that defines the ecryptfs_verbosity level.
+ */
+int ecryptfs_verbosity = 0;
+
+module_param(ecryptfs_verbosity, int, 0);
+MODULE_PARM_DESC(ecryptfs_verbosity,
+		 "Initial verbosity level (0 or 1; defaults to "
+		 "0, which is Quiet)");
+
+void __ecryptfs_printk(const char *fmt, ...)
+{
+	va_list args;
+	va_start(args, fmt);
+	if (fmt[1] == '7') { /* KERN_DEBUG */
+		if (ecryptfs_verbosity >= 1)
+			vprintk(fmt, args);
+	} else
+		vprintk(fmt, args);
+	va_end(args);
+}
+
+/**
+ * ecryptfs_interpose
+ * @lower_dentry: Existing dentry in the lower filesystem
+ * @dentry: ecryptfs' dentry
+ * @sb: ecryptfs's super_block
+ * @flag: If set to true, then d_add is called, else d_instantiate is called
+ *
+ * Interposes upper and lower dentries.
+ *
+ * Returns zero on success; non-zero otherwise
+ */
+int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry,
+		       struct super_block *sb, int flag)
+{
+	struct inode *lower_inode;
+	struct inode *inode;
+	int rc = 0;
+
+	lower_inode = lower_dentry->d_inode;
+	if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb)) {
+		rc = -EXDEV;
+		goto out;
+	}
+	if (!igrab(lower_inode)) {
+		rc = -ESTALE;
+		goto out;
+	}
+	inode = iget5_locked(sb, (unsigned long)lower_inode,
+			     ecryptfs_inode_test, ecryptfs_inode_set,
+			     lower_inode);
+	if (!inode) {
+		rc = -EACCES;
+		iput(lower_inode);
+		goto out;
+	}
+	if (inode->i_state & I_NEW)
+		unlock_new_inode(inode);
+	else
+		iput(lower_inode);
+	if (S_ISLNK(lower_inode->i_mode))
+		inode->i_op = &ecryptfs_symlink_iops;
+	else if (S_ISDIR(lower_inode->i_mode))
+		inode->i_op = &ecryptfs_dir_iops;
+	if (S_ISDIR(lower_inode->i_mode))
+		inode->i_fop = &ecryptfs_dir_fops;
+	if (special_file(lower_inode->i_mode))
+		init_special_inode(inode, lower_inode->i_mode,
+				   lower_inode->i_rdev);
+	dentry->d_op = &ecryptfs_dops;
+	if (flag)
+		d_add(dentry, inode);
+	else
+		d_instantiate(dentry, inode);
+	ecryptfs_copy_attr_all(inode, lower_inode);
+	/* This size will be overwritten for real files w/ headers and
+	 * other metadata */
+	ecryptfs_copy_inode_size(inode, lower_inode);
+out:
+	return rc;
+}
+
+enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig, ecryptfs_opt_debug,
+       ecryptfs_opt_ecryptfs_debug, ecryptfs_opt_cipher,
+       ecryptfs_opt_ecryptfs_cipher, ecryptfs_opt_ecryptfs_key_bytes,
+       ecryptfs_opt_passthrough, ecryptfs_opt_err };
+
+static match_table_t tokens = {
+	{ecryptfs_opt_sig, "sig=%s"},
+	{ecryptfs_opt_ecryptfs_sig, "ecryptfs_sig=%s"},
+	{ecryptfs_opt_debug, "debug=%u"},
+	{ecryptfs_opt_ecryptfs_debug, "ecryptfs_debug=%u"},
+	{ecryptfs_opt_cipher, "cipher=%s"},
+	{ecryptfs_opt_ecryptfs_cipher, "ecryptfs_cipher=%s"},
+	{ecryptfs_opt_ecryptfs_key_bytes, "ecryptfs_key_bytes=%u"},
+	{ecryptfs_opt_passthrough, "ecryptfs_passthrough"},
+	{ecryptfs_opt_err, NULL}
+};
+
+/**
+ * ecryptfs_verify_version
+ * @version: The version number to confirm
+ *
+ * Returns zero on good version; non-zero otherwise
+ */
+static int ecryptfs_verify_version(u16 version)
+{
+	int rc = 0;
+	unsigned char major;
+	unsigned char minor;
+
+	major = ((version >> 8) & 0xFF);
+	minor = (version & 0xFF);
+	if (major != ECRYPTFS_VERSION_MAJOR) {
+		ecryptfs_printk(KERN_ERR, "Major version number mismatch. "
+				"Expected [%d]; got [%d]\n",
+				ECRYPTFS_VERSION_MAJOR, major);
+		rc = -EINVAL;
+		goto out;
+	}
+	if (minor != ECRYPTFS_VERSION_MINOR) {
+		ecryptfs_printk(KERN_ERR, "Minor version number mismatch. "
+				"Expected [%d]; got [%d]\n",
+				ECRYPTFS_VERSION_MINOR, minor);
+		rc = -EINVAL;
+		goto out;
+	}
+out:
+	return rc;
+}
+
+/**
+ * ecryptfs_parse_options
+ * @sb: The ecryptfs super block
+ * @options: The options pased to the kernel
+ *
+ * Parse mount options:
+ * debug=N 	   - ecryptfs_verbosity level for debug output
+ * sig=XXX	   - description(signature) of the key to use
+ *
+ * Returns the dentry object of the lower-level (lower/interposed)
+ * directory; We want to mount our stackable file system on top of
+ * that lower directory.
+ *
+ * The signature of the key to use must be the description of a key
+ * already in the keyring. Mounting will fail if the key can not be
+ * found.
+ *
+ * Returns zero on success; non-zero on error
+ */
+static int ecryptfs_parse_options(struct super_block *sb, char *options)
+{
+	char *p;
+	int rc = 0;
+	int sig_set = 0;
+	int cipher_name_set = 0;
+	int cipher_key_bytes;
+	int cipher_key_bytes_set = 0;
+	struct key *auth_tok_key = NULL;
+	struct ecryptfs_auth_tok *auth_tok = NULL;
+	struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
+		&ecryptfs_superblock_to_private(sb)->mount_crypt_stat;
+	substring_t args[MAX_OPT_ARGS];
+	int token;
+	char *sig_src;
+	char *sig_dst;
+	char *debug_src;
+	char *cipher_name_dst;
+	char *cipher_name_src;
+	char *cipher_key_bytes_src;
+	struct crypto_tfm *tmp_tfm;
+	int cipher_name_len;
+
+	if (!options) {
+		rc = -EINVAL;
+		goto out;
+	}
+	while ((p = strsep(&options, ",")) != NULL) {
+		if (!*p)
+			continue;
+		token = match_token(p, tokens, args);
+		switch (token) {
+		case ecryptfs_opt_sig:
+		case ecryptfs_opt_ecryptfs_sig:
+			sig_src = args[0].from;
+			sig_dst =
+				mount_crypt_stat->global_auth_tok_sig;
+			memcpy(sig_dst, sig_src, ECRYPTFS_SIG_SIZE_HEX);
+			sig_dst[ECRYPTFS_SIG_SIZE_HEX] = '\0';
+			ecryptfs_printk(KERN_DEBUG,
+					"The mount_crypt_stat "
+					"global_auth_tok_sig set to: "
+					"[%s]\n", sig_dst);
+			sig_set = 1;
+			break;
+		case ecryptfs_opt_debug:
+		case ecryptfs_opt_ecryptfs_debug:
+			debug_src = args[0].from;
+			ecryptfs_verbosity =
+				(int)simple_strtol(debug_src, &debug_src,
+						   0);
+			ecryptfs_printk(KERN_DEBUG,
+					"Verbosity set to [%d]" "\n",
+					ecryptfs_verbosity);
+			break;
+		case ecryptfs_opt_cipher:
+		case ecryptfs_opt_ecryptfs_cipher:
+			cipher_name_src = args[0].from;
+			cipher_name_dst =
+				mount_crypt_stat->
+				global_default_cipher_name;
+			strncpy(cipher_name_dst, cipher_name_src,
+				ECRYPTFS_MAX_CIPHER_NAME_SIZE);
+			ecryptfs_printk(KERN_DEBUG,
+					"The mount_crypt_stat "
+					"global_default_cipher_name set to: "
+					"[%s]\n", cipher_name_dst);
+			cipher_name_set = 1;
+			break;
+		case ecryptfs_opt_ecryptfs_key_bytes:
+			cipher_key_bytes_src = args[0].from;
+			cipher_key_bytes =
+				(int)simple_strtol(cipher_key_bytes_src,
+						   &cipher_key_bytes_src, 0);
+			mount_crypt_stat->global_default_cipher_key_size =
+				cipher_key_bytes;
+			ecryptfs_printk(KERN_DEBUG,
+					"The mount_crypt_stat "
+					"global_default_cipher_key_size "
+					"set to: [%d]\n", mount_crypt_stat->
+					global_default_cipher_key_size);
+			cipher_key_bytes_set = 1;
+			break;
+		case ecryptfs_opt_passthrough:
+			mount_crypt_stat->flags |=
+				ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED;
+			break;
+		case ecryptfs_opt_err:
+		default:
+			ecryptfs_printk(KERN_WARNING,
+					"eCryptfs: unrecognized option '%s'\n",
+					p);
+		}
+	}
+	/* Do not support lack of mount-wide signature in 0.1
+	 * release */
+	if (!sig_set) {
+		rc = -EINVAL;
+		ecryptfs_printk(KERN_ERR, "You must supply a valid "
+				"passphrase auth tok signature as a mount "
+				"parameter; see the eCryptfs README\n");
+		goto out;
+	}
+	if (!cipher_name_set) {
+		cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER);
+		if (unlikely(cipher_name_len
+			     >= ECRYPTFS_MAX_CIPHER_NAME_SIZE)) {
+			rc = -EINVAL;
+			BUG();
+			goto out;
+		}
+		memcpy(mount_crypt_stat->global_default_cipher_name,
+		       ECRYPTFS_DEFAULT_CIPHER, cipher_name_len);
+		mount_crypt_stat->global_default_cipher_name[cipher_name_len]
+		    = '\0';
+	}
+	if (!cipher_key_bytes_set) {
+		mount_crypt_stat->global_default_cipher_key_size =
+			ECRYPTFS_DEFAULT_KEY_BYTES;
+		ecryptfs_printk(KERN_DEBUG, "Cipher key size was not "
+				"specified.  Defaulting to [%d]\n",
+				mount_crypt_stat->
+				global_default_cipher_key_size);
+	}
+	rc = ecryptfs_process_cipher(
+		&tmp_tfm,
+		&mount_crypt_stat->global_key_tfm,
+		mount_crypt_stat->global_default_cipher_name,
+		mount_crypt_stat->global_default_cipher_key_size);
+	if (tmp_tfm)
+		crypto_free_tfm(tmp_tfm);
+	if (rc) {
+		printk(KERN_ERR "Error attempting to initialize cipher [%s] "
+		       "with key size [%Zd] bytes; rc = [%d]\n",
+		       mount_crypt_stat->global_default_cipher_name,
+		       mount_crypt_stat->global_default_cipher_key_size, rc);
+		rc = -EINVAL;
+		goto out;
+	}
+	mutex_init(&mount_crypt_stat->global_key_tfm_mutex);
+	ecryptfs_printk(KERN_DEBUG, "Requesting the key with description: "
+			"[%s]\n", mount_crypt_stat->global_auth_tok_sig);
+	/* The reference to this key is held until umount is done The
+	 * call to key_put is done in ecryptfs_put_super() */
+	auth_tok_key = request_key(&key_type_user,
+				   mount_crypt_stat->global_auth_tok_sig,
+				   NULL);
+	if (!auth_tok_key || IS_ERR(auth_tok_key)) {
+		ecryptfs_printk(KERN_ERR, "Could not find key with "
+				"description: [%s]\n",
+				mount_crypt_stat->global_auth_tok_sig);
+		process_request_key_err(PTR_ERR(auth_tok_key));
+		rc = -EINVAL;
+		goto out;
+	}
+	auth_tok = ecryptfs_get_key_payload_data(auth_tok_key);
+	if (ecryptfs_verify_version(auth_tok->version)) {
+		ecryptfs_printk(KERN_ERR, "Data structure version mismatch. "
+				"Userspace tools must match eCryptfs kernel "
+				"module with major version [%d] and minor "
+				"version [%d]\n", ECRYPTFS_VERSION_MAJOR,
+				ECRYPTFS_VERSION_MINOR);
+		rc = -EINVAL;
+		goto out;
+	}
+	if (auth_tok->token_type != ECRYPTFS_PASSWORD) {
+		ecryptfs_printk(KERN_ERR, "Invalid auth_tok structure "
+				"returned from key\n");
+		rc = -EINVAL;
+		goto out;
+	}
+	mount_crypt_stat->global_auth_tok_key = auth_tok_key;
+	mount_crypt_stat->global_auth_tok = auth_tok;
+out:
+	return rc;
+}
+
+struct kmem_cache *ecryptfs_sb_info_cache;
+
+/**
+ * ecryptfs_fill_super
+ * @sb: The ecryptfs super block
+ * @raw_data: The options passed to mount
+ * @silent: Not used but required by function prototype
+ *
+ * Sets up what we can of the sb, rest is done in ecryptfs_read_super
+ *
+ * Returns zero on success; non-zero otherwise
+ */
+static int
+ecryptfs_fill_super(struct super_block *sb, void *raw_data, int silent)
+{
+	int rc = 0;
+
+	/* Released in ecryptfs_put_super() */
+	ecryptfs_set_superblock_private(sb,
+					kmem_cache_alloc(ecryptfs_sb_info_cache,
+							 SLAB_KERNEL));
+	if (!ecryptfs_superblock_to_private(sb)) {
+		ecryptfs_printk(KERN_WARNING, "Out of memory\n");
+		rc = -ENOMEM;
+		goto out;
+	}
+	memset(ecryptfs_superblock_to_private(sb), 0,
+	       sizeof(struct ecryptfs_sb_info));
+	sb->s_op = &ecryptfs_sops;
+	/* Released through deactivate_super(sb) from get_sb_nodev */
+	sb->s_root = d_alloc(NULL, &(const struct qstr) {
+			     .hash = 0,.name = "/",.len = 1});
+	if (!sb->s_root) {
+		ecryptfs_printk(KERN_ERR, "d_alloc failed\n");
+		rc = -ENOMEM;
+		goto out;
+	}
+	sb->s_root->d_op = &ecryptfs_dops;
+	sb->s_root->d_sb = sb;
+	sb->s_root->d_parent = sb->s_root;
+	/* Released in d_release when dput(sb->s_root) is called */
+	/* through deactivate_super(sb) from get_sb_nodev() */
+	ecryptfs_set_dentry_private(sb->s_root,
+				    kmem_cache_alloc(ecryptfs_dentry_info_cache,
+						     SLAB_KERNEL));
+	if (!ecryptfs_dentry_to_private(sb->s_root)) {
+		ecryptfs_printk(KERN_ERR,
+				"dentry_info_cache alloc failed\n");
+		rc = -ENOMEM;
+		goto out;
+	}
+	memset(ecryptfs_dentry_to_private(sb->s_root), 0,
+	       sizeof(struct ecryptfs_dentry_info));
+	rc = 0;
+out:
+	/* Should be able to rely on deactivate_super called from
+	 * get_sb_nodev */
+	return rc;
+}
+
+/**
+ * ecryptfs_read_super
+ * @sb: The ecryptfs super block
+ * @dev_name: The path to mount over
+ *
+ * Read the super block of the lower filesystem, and use
+ * ecryptfs_interpose to create our initial inode and super block
+ * struct.
+ */
+static int ecryptfs_read_super(struct super_block *sb, const char *dev_name)
+{
+	int rc;
+	struct nameidata nd;
+	struct dentry *lower_root;
+	struct vfsmount *lower_mnt;
+
+	memset(&nd, 0, sizeof(struct nameidata));
+	rc = path_lookup(dev_name, LOOKUP_FOLLOW, &nd);
+	if (rc) {
+		ecryptfs_printk(KERN_WARNING, "path_lookup() failed\n");
+		goto out_free;
+	}
+	lower_root = nd.dentry;
+	if (!lower_root->d_inode) {
+		ecryptfs_printk(KERN_WARNING,
+				"No directory to interpose on\n");
+		rc = -ENOENT;
+		goto out_free;
+	}
+	lower_mnt = nd.mnt;
+	ecryptfs_set_superblock_lower(sb, lower_root->d_sb);
+	sb->s_maxbytes = lower_root->d_sb->s_maxbytes;
+	ecryptfs_set_dentry_lower(sb->s_root, lower_root);
+	ecryptfs_set_dentry_lower_mnt(sb->s_root, lower_mnt);
+	if ((rc = ecryptfs_interpose(lower_root, sb->s_root, sb, 0)))
+		goto out_free;
+	rc = 0;
+	goto out;
+out_free:
+	path_release(&nd);
+out:
+	return rc;
+}
+
+/**
+ * ecryptfs_get_sb
+ * @fs_type
+ * @flags
+ * @dev_name: The path to mount over
+ * @raw_data: The options passed into the kernel
+ *
+ * The whole ecryptfs_get_sb process is broken into 4 functions:
+ * ecryptfs_parse_options(): handle options passed to ecryptfs, if any
+ * ecryptfs_fill_super(): used by get_sb_nodev, fills out the super_block
+ *                        with as much information as it can before needing
+ *                        the lower filesystem.
+ * ecryptfs_read_super(): this accesses the lower filesystem and uses
+ *                        ecryptfs_interpolate to perform most of the linking
+ * ecryptfs_interpolate(): links the lower filesystem into ecryptfs
+ */
+static int ecryptfs_get_sb(struct file_system_type *fs_type, int flags,
+			const char *dev_name, void *raw_data,
+			struct vfsmount *mnt)
+{
+	int rc;
+	struct super_block *sb;
+
+	rc = get_sb_nodev(fs_type, flags, raw_data, ecryptfs_fill_super, mnt);
+	if (rc < 0) {
+		printk(KERN_ERR "Getting sb failed; rc = [%d]\n", rc);
+		goto out;
+	}
+	sb = mnt->mnt_sb;
+	rc = ecryptfs_parse_options(sb, raw_data);
+	if (rc) {
+		printk(KERN_ERR "Error parsing options; rc = [%d]\n", rc);
+		goto out_abort;
+	}
+	rc = ecryptfs_read_super(sb, dev_name);
+	if (rc) {
+		printk(KERN_ERR "Reading sb failed; rc = [%d]\n", rc);
+		goto out_abort;
+	}
+	goto out;
+out_abort:
+	dput(sb->s_root);
+	up_write(&sb->s_umount);
+	deactivate_super(sb);
+out:
+	return rc;
+}
+
+/**
+ * ecryptfs_kill_block_super
+ * @sb: The ecryptfs super block
+ *
+ * Used to bring the superblock down and free the private data.
+ * Private data is free'd in ecryptfs_put_super()
+ */
+static void ecryptfs_kill_block_super(struct super_block *sb)
+{
+	generic_shutdown_super(sb);
+}
+
+static struct file_system_type ecryptfs_fs_type = {
+	.owner = THIS_MODULE,
+	.name = "ecryptfs",
+	.get_sb = ecryptfs_get_sb,
+	.kill_sb = ecryptfs_kill_block_super,
+	.fs_flags = 0
+};
+
+/**
+ * inode_info_init_once
+ *
+ * Initializes the ecryptfs_inode_info_cache when it is created
+ */
+static void
+inode_info_init_once(void *vptr, struct kmem_cache *cachep, unsigned long flags)
+{
+	struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr;
+
+	if ((flags & (SLAB_CTOR_VERIFY | SLAB_CTOR_CONSTRUCTOR)) ==
+	    SLAB_CTOR_CONSTRUCTOR)
+		inode_init_once(&ei->vfs_inode);
+}
+
+static struct ecryptfs_cache_info {
+	kmem_cache_t **cache;
+	const char *name;
+	size_t size;
+	void (*ctor)(void*, struct kmem_cache *, unsigned long);
+} ecryptfs_cache_infos[] = {
+	{
+		.cache = &ecryptfs_auth_tok_list_item_cache,
+		.name = "ecryptfs_auth_tok_list_item",
+		.size = sizeof(struct ecryptfs_auth_tok_list_item),
+	},
+	{
+		.cache = &ecryptfs_file_info_cache,
+		.name = "ecryptfs_file_cache",
+		.size = sizeof(struct ecryptfs_file_info),
+	},
+	{
+		.cache = &ecryptfs_dentry_info_cache,
+		.name = "ecryptfs_dentry_info_cache",
+		.size = sizeof(struct ecryptfs_dentry_info),
+	},
+	{
+		.cache = &ecryptfs_inode_info_cache,
+		.name = "ecryptfs_inode_cache",
+		.size = sizeof(struct ecryptfs_inode_info),
+		.ctor = inode_info_init_once,
+	},
+	{
+		.cache = &ecryptfs_sb_info_cache,
+		.name = "ecryptfs_sb_cache",
+		.size = sizeof(struct ecryptfs_sb_info),
+	},
+	{
+		.cache = &ecryptfs_header_cache_0,
+		.name = "ecryptfs_headers_0",
+		.size = PAGE_CACHE_SIZE,
+	},
+	{
+		.cache = &ecryptfs_header_cache_1,
+		.name = "ecryptfs_headers_1",
+		.size = PAGE_CACHE_SIZE,
+	},
+	{
+		.cache = &ecryptfs_header_cache_2,
+		.name = "ecryptfs_headers_2",
+		.size = PAGE_CACHE_SIZE,
+	},
+	{
+		.cache = &ecryptfs_lower_page_cache,
+		.name = "ecryptfs_lower_page_cache",
+		.size = PAGE_CACHE_SIZE,
+	},
+};
+
+static void ecryptfs_free_kmem_caches(void)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
+		struct ecryptfs_cache_info *info;
+
+		info = &ecryptfs_cache_infos[i];
+		if (*(info->cache))
+			kmem_cache_destroy(*(info->cache));
+	}
+}
+
+/**
+ * ecryptfs_init_kmem_caches
+ *
+ * Returns zero on success; non-zero otherwise
+ */
+static int ecryptfs_init_kmem_caches(void)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
+		struct ecryptfs_cache_info *info;
+
+		info = &ecryptfs_cache_infos[i];
+		*(info->cache) = kmem_cache_create(info->name, info->size,
+				0, SLAB_HWCACHE_ALIGN, info->ctor, NULL);
+		if (!*(info->cache)) {
+			ecryptfs_free_kmem_caches();
+			ecryptfs_printk(KERN_WARNING, "%s: "
+					"kmem_cache_create failed\n",
+					info->name);
+			return -ENOMEM;
+		}
+	}
+	return 0;
+}
+
+struct ecryptfs_obj {
+	char *name;
+	struct list_head slot_list;
+	struct kobject kobj;
+};
+
+struct ecryptfs_attribute {
+	struct attribute attr;
+	ssize_t(*show) (struct ecryptfs_obj *, char *);
+	ssize_t(*store) (struct ecryptfs_obj *, const char *, size_t);
+};
+
+static ssize_t
+ecryptfs_attr_store(struct kobject *kobj,
+		    struct attribute *attr, const char *buf, size_t len)
+{
+	struct ecryptfs_obj *obj = container_of(kobj, struct ecryptfs_obj,
+						kobj);
+	struct ecryptfs_attribute *attribute =
+		container_of(attr, struct ecryptfs_attribute, attr);
+
+	return (attribute->store ? attribute->store(obj, buf, len) : 0);
+}
+
+static ssize_t
+ecryptfs_attr_show(struct kobject *kobj, struct attribute *attr, char *buf)
+{
+	struct ecryptfs_obj *obj = container_of(kobj, struct ecryptfs_obj,
+						kobj);
+	struct ecryptfs_attribute *attribute =
+		container_of(attr, struct ecryptfs_attribute, attr);
+
+	return (attribute->show ? attribute->show(obj, buf) : 0);
+}
+
+static struct sysfs_ops ecryptfs_sysfs_ops = {
+	.show = ecryptfs_attr_show,
+	.store = ecryptfs_attr_store
+};
+
+static struct kobj_type ecryptfs_ktype = {
+	.sysfs_ops = &ecryptfs_sysfs_ops
+};
+
+static decl_subsys(ecryptfs, &ecryptfs_ktype, NULL);
+
+static ssize_t version_show(struct ecryptfs_obj *obj, char *buff)
+{
+	return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK);
+}
+
+static struct ecryptfs_attribute sysfs_attr_version = __ATTR_RO(version);
+
+struct ecryptfs_version_str_map_elem {
+	u32 flag;
+	char *str;
+} ecryptfs_version_str_map[] = {
+	{ECRYPTFS_VERSIONING_PASSPHRASE, "passphrase"},
+	{ECRYPTFS_VERSIONING_PUBKEY, "pubkey"},
+	{ECRYPTFS_VERSIONING_PLAINTEXT_PASSTHROUGH, "plaintext passthrough"},
+	{ECRYPTFS_VERSIONING_POLICY, "policy"}
+};
+
+static ssize_t version_str_show(struct ecryptfs_obj *obj, char *buff)
+{
+	int i;
+	int remaining = PAGE_SIZE;
+	int total_written = 0;
+
+	buff[0] = '\0';
+	for (i = 0; i < ARRAY_SIZE(ecryptfs_version_str_map); i++) {
+		int entry_size;
+
+		if (!(ECRYPTFS_VERSIONING_MASK
+		      & ecryptfs_version_str_map[i].flag))
+			continue;
+		entry_size = strlen(ecryptfs_version_str_map[i].str);
+		if ((entry_size + 2) > remaining)
+			goto out;
+		memcpy(buff, ecryptfs_version_str_map[i].str, entry_size);
+		buff[entry_size++] = '\n';
+		buff[entry_size] = '\0';
+		buff += entry_size;
+		total_written += entry_size;
+		remaining -= entry_size;
+	}
+out:
+	return total_written;
+}
+
+static struct ecryptfs_attribute sysfs_attr_version_str = __ATTR_RO(version_str);
+
+static int do_sysfs_registration(void)
+{
+	int rc;
+
+	if ((rc = subsystem_register(&ecryptfs_subsys))) {
+		printk(KERN_ERR
+		       "Unable to register ecryptfs sysfs subsystem\n");
+		goto out;
+	}
+	rc = sysfs_create_file(&ecryptfs_subsys.kset.kobj,
+			       &sysfs_attr_version.attr);
+	if (rc) {
+		printk(KERN_ERR
+		       "Unable to create ecryptfs version attribute\n");
+		subsystem_unregister(&ecryptfs_subsys);
+		goto out;
+	}
+	rc = sysfs_create_file(&ecryptfs_subsys.kset.kobj,
+			       &sysfs_attr_version_str.attr);
+	if (rc) {
+		printk(KERN_ERR
+		       "Unable to create ecryptfs version_str attribute\n");
+		sysfs_remove_file(&ecryptfs_subsys.kset.kobj,
+				  &sysfs_attr_version.attr);
+		subsystem_unregister(&ecryptfs_subsys);
+		goto out;
+	}
+out:
+	return rc;
+}
+
+static int __init ecryptfs_init(void)
+{
+	int rc;
+
+	if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_CACHE_SIZE) {
+		rc = -EINVAL;
+		ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is "
+				"larger than the host's page size, and so "
+				"eCryptfs cannot run on this system. The "
+				"default eCryptfs extent size is [%d] bytes; "
+				"the page size is [%d] bytes.\n",
+				ECRYPTFS_DEFAULT_EXTENT_SIZE, PAGE_CACHE_SIZE);
+		goto out;
+	}
+	rc = ecryptfs_init_kmem_caches();
+	if (rc) {
+		printk(KERN_ERR
+		       "Failed to allocate one or more kmem_cache objects\n");
+		goto out;
+	}
+	rc = register_filesystem(&ecryptfs_fs_type);
+	if (rc) {
+		printk(KERN_ERR "Failed to register filesystem\n");
+		ecryptfs_free_kmem_caches();
+		goto out;
+	}
+	kset_set_kset_s(&ecryptfs_subsys, fs_subsys);
+	sysfs_attr_version.attr.owner = THIS_MODULE;
+	sysfs_attr_version_str.attr.owner = THIS_MODULE;
+	rc = do_sysfs_registration();
+	if (rc) {
+		printk(KERN_ERR "sysfs registration failed\n");
+		unregister_filesystem(&ecryptfs_fs_type);
+		ecryptfs_free_kmem_caches();
+		goto out;
+	}
+out:
+	return rc;
+}
+
+static void __exit ecryptfs_exit(void)
+{
+	sysfs_remove_file(&ecryptfs_subsys.kset.kobj,
+			  &sysfs_attr_version.attr);
+	sysfs_remove_file(&ecryptfs_subsys.kset.kobj,
+			  &sysfs_attr_version_str.attr);
+	subsystem_unregister(&ecryptfs_subsys);
+	unregister_filesystem(&ecryptfs_fs_type);
+	ecryptfs_free_kmem_caches();
+}
+
+MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>");
+MODULE_DESCRIPTION("eCryptfs");
+
+MODULE_LICENSE("GPL");
+
+module_init(ecryptfs_init)
+module_exit(ecryptfs_exit)