[PATCH 4/13: eCryptfs] Main module functions

Phillip Hellewell
2006-05-13T03:42:54Z

This is the 4th patch in a series of 13 constituting the kernel
components of the eCryptfs cryptographic filesystem.

Provides functions to initialize the eCryptfs module and eCryptfs
mounts. Allocates and deallocates kmem_cache regions.

Signed-off-by: Phillip Hellewell <phillip@hellewell.homeip.net>
Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>

---

main.c | 767 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 767 insertions(+)

Index: linux-2.6.17-rc3-mm1-ecryptfs/fs/ecryptfs/main.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6.17-rc3-mm1-ecryptfs/fs/ecryptfs/main.c 2006-05-12 20:00:29.000000000 -0600
@@ -0,0 +1,767 @@
+/**
+ * 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/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.
+ *
+ * This function will allocate an ecryptfs_inode through the call to
+ * iget(sb, lower_inode->i_ino).
+ *
+ * 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;
+ int rc = 0;
+ struct inode *inode;
+
+ lower_inode = lower_dentry->d_inode;
+ if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb)) {
+ rc = -EXDEV;
+ goto out;
+ }
+ inode = iget(sb, lower_inode->i_ino);
+ if (!inode) {
+ rc = -EACCES;
+ goto out;
+ }
+ /* This check is required here because if we failed to allocated the
+ * required space for an inode_info_cache struct, then the only way
+ * we know we failed, is by the pointer being NULL */
+ if (!ecryptfs_inode_to_private(inode)) {
+ ecryptfs_printk(KERN_ERR, "Out of memory. Failure to "
+ "allocate memory in ecryptfs_read_inode.\n");
+ rc = -ENOMEM;
+ goto out;
+ }
+ if (NULL == ecryptfs_inode_to_lower(inode))
+ ecryptfs_set_inode_lower(inode, igrab(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;
+ /* TODO: Is there a better way to identify if the inode is
+ * special? */
+ if (S_ISBLK(lower_inode->i_mode) || S_ISCHR(lower_inode->i_mode) ||
+ S_ISFIFO(lower_inode->i_mode) || S_ISSOCK(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_debug, ecryptfs_opt_cipher,
+ ecryptfs_opt_err };
+
+static match_table_t tokens = {
+ {ecryptfs_opt_sig, "sig=%s"},
+ {ecryptfs_opt_debug, "debug=%u"},
+ {ecryptfs_opt_cipher, "cipher=%s"},
+ {ecryptfs_opt_err, NULL}
+};
+
+/**
+ * ecryptfs_verify_version
+ * @version: The version number to confirm
+ *
+ * Returns zero on good version; non-zero otherwise
+ */
+int ecryptfs_verify_version(uint16_t 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;
+ 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;
+ 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:
+ 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:
+ 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:
+ 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_err:
+ default:
+ ecryptfs_printk(KERN_WARNING,
+ "eCryptfs: unrecognized option '%s'\n",
+ options);
+ }
+ }
+ /* 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';
+ }
+ 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 (!ECRYPTFS_CHECK_FLAG(auth_tok->flags, 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_cleanup_read_super
+ * @sb: The ecryptfs super block
+ *
+ * Preform the cleanup for ecryptfs_read_super()
+ */
+static inline void ecryptfs_cleanup_read_super(struct super_block *sb)
+{
+ up_write(&sb->s_umount);
+ deactivate_super(sb);
+}
+
+/**
+ * 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 deactive_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;
+
+ 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;
+ ecryptfs_superblock_to_private(sb)->lower_mnt = nd.mnt;
+ if (!lower_root->d_inode) {
+ ecryptfs_printk(KERN_WARNING,
+ "No directory to interpose on\n");
+ rc = -ENOENT;
+ goto out_free;
+ }
+ 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);
+ if ((rc = ecryptfs_interpose(lower_root, sb->s_root, sb, 0)))
+ goto out_free;
+ rc = 0;
+ goto out;
+out_free:
+ path_release(&nd);
+ ecryptfs_cleanup_read_super(sb);
+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 struct super_block *ecryptfs_get_sb(struct file_system_type *fs_type,
+ int flags, const char *dev_name,
+ void *raw_data)
+{
+ int rc;
+ struct super_block *sb = NULL;
+
+ sb = get_sb_nodev(fs_type, flags, raw_data, ecryptfs_fill_super);
+ if (IS_ERR(sb)) {
+ ecryptfs_printk(KERN_ERR, "Getting sb failed. "
+ "sb = [%p]\n", sb);
+ goto out;
+ }
+ rc = ecryptfs_parse_options(sb, raw_data);
+ if (rc) {
+ sb = ERR_PTR(rc);
+ goto out;
+ }
+ rc = ecryptfs_read_super(sb, dev_name);
+ if (rc) {
+ sb = ERR_PTR(rc);
+ ecryptfs_printk(KERN_ERR, "Reading sb failed. "
+ "sb = [%p]\n", sb);
+ }
+out:
+ return sb;
+}
+
+/**
+ * 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)
+{
+ struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
+ &(ecryptfs_superblock_to_private(sb)->mount_crypt_stat);
+
+ memset(mount_crypt_stat, 0, sizeof(struct ecryptfs_mount_crypt_stat));
+ 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);
+}
+
+/* This provides a means of backing out cache creations out of the kernel
+ * so that we can elegantly fail should we run out of memory.
+ */
+#define ECRYPTFS_AUTH_TOK_LIST_ITEM_CACHE 0x0001
+#define ECRYPTFS_AUTH_TOK_PKT_SET_CACHE 0x0002
+#define ECRYPTFS_AUTH_TOK_REQUEST_CACHE 0x0004
+#define ECRYPTFS_AUTH_TOK_REQUEST_BLOB_CACHE 0x0008
+#define ECRYPTFS_FILE_INFO_CACHE 0x0010
+#define ECRYPTFS_DENTRY_INFO_CACHE 0x0020
+#define ECRYPTFS_INODE_INFO_CACHE 0x0040
+#define ECRYPTFS_SB_INFO_CACHE 0x0080
+#define ECRYPTFS_HEADER_CACHE_0 0x0100
+#define ECRYPTFS_HEADER_CACHE_1 0x0200
+#define ECRYPTFS_HEADER_CACHE_2 0x0400
+#define ECRYPTFS_LOWER_PAGE_CACHE 0x0800
+#define ECRYPTFS_CACHE_CREATION_SUCCESS 0x0FF1
+
+static short ecryptfs_allocated_caches;
+
+/**
+ * ecryptfs_init_kmem_caches
+ *
+ * Sets ecryptfs_allocated_caches with flags so that we can
+ * free created caches should we run out of memory during
+ * creation period.
+ *
+ * Returns zero on success; non-zero otherwise
+ */
+static int ecryptfs_init_kmem_caches(void)
+{
+ int rc = 0;
+
+ ecryptfs_auth_tok_list_item_cache =
+ kmem_cache_create("ecryptfs_auth_tok_list_item",
+ sizeof(struct ecryptfs_auth_tok_list_item),
+ 0, SLAB_HWCACHE_ALIGN, NULL, NULL);
+ if (ecryptfs_auth_tok_list_item_cache)
+ rc |= ECRYPTFS_AUTH_TOK_LIST_ITEM_CACHE;
+ else
+ ecryptfs_printk(KERN_WARNING, "ecryptfs_auth_tok_list_item "
+ "kmem_cache_create failed\n");
+
+ ecryptfs_file_info_cache =
+ kmem_cache_create("ecryptfs_file_cache",
+ sizeof(struct ecryptfs_file_info),
+ 0, SLAB_HWCACHE_ALIGN, NULL, NULL);
+ if (ecryptfs_file_info_cache)
+ rc |= ECRYPTFS_FILE_INFO_CACHE;
+ else
+ ecryptfs_printk(KERN_WARNING, "ecryptfs_file_cache "
+ "kmem_cache_create failed\n");
+
+ ecryptfs_dentry_info_cache =
+ kmem_cache_create("ecryptfs_dentry_cache",
+ sizeof(struct ecryptfs_dentry_info),
+ 0, SLAB_HWCACHE_ALIGN, NULL, NULL);
+ if (ecryptfs_dentry_info_cache)
+ rc |= ECRYPTFS_DENTRY_INFO_CACHE;
+ else
+ ecryptfs_printk(KERN_WARNING, "ecryptfs_dentry_cache "
+ "kmem_cache_create failed\n");
+
+ ecryptfs_inode_info_cache =
+ kmem_cache_create("ecryptfs_inode_cache",
+ sizeof(struct ecryptfs_inode_info), 0,
+ SLAB_HWCACHE_ALIGN, inode_info_init_once, NULL);
+ if (ecryptfs_inode_info_cache)
+ rc |= ECRYPTFS_INODE_INFO_CACHE;
+ else
+ ecryptfs_printk(KERN_WARNING, "ecryptfs_inode_cache "
+ "kmem_cache_create failed\n");
+
+ ecryptfs_sb_info_cache =
+ kmem_cache_create("ecryptfs_sb_cache",
+ sizeof(struct ecryptfs_sb_info),
+ 0, SLAB_HWCACHE_ALIGN, NULL, NULL);
+ if (ecryptfs_sb_info_cache)
+ rc |= ECRYPTFS_SB_INFO_CACHE;
+ else
+ ecryptfs_printk(KERN_WARNING, "ecryptfs_sb_cache "
+ "kmem_cache_create failed\n");
+
+ ecryptfs_header_cache_0 =
+ kmem_cache_create("ecryptfs_headers_0", PAGE_CACHE_SIZE,
+ 0, SLAB_HWCACHE_ALIGN, NULL, NULL);
+ if (ecryptfs_header_cache_0)
+ rc |= ECRYPTFS_HEADER_CACHE_0;
+ else
+ ecryptfs_printk(KERN_WARNING, "ecryptfs_headers_0 "
+ "kmem_cache_create failed\n");
+
+ ecryptfs_header_cache_1 =
+ kmem_cache_create("ecryptfs_headers_1", PAGE_CACHE_SIZE,
+ 0, SLAB_HWCACHE_ALIGN, NULL, NULL);
+ if (ecryptfs_header_cache_1)
+ rc |= ECRYPTFS_HEADER_CACHE_1;
+ else
+ ecryptfs_printk(KERN_WARNING, "ecryptfs_headers_1 "
+ "kmem_cache_create failed\n");
+
+ ecryptfs_header_cache_2 =
+ kmem_cache_create("ecryptfs_headers_2", PAGE_CACHE_SIZE,
+ 0, SLAB_HWCACHE_ALIGN, NULL, NULL);
+ if (ecryptfs_header_cache_2)
+ rc |= ECRYPTFS_HEADER_CACHE_2;
+ else
+ ecryptfs_printk(KERN_WARNING, "ecryptfs_headers_2 "
+ "kmem_cache_create failed\n");
+
+ ecryptfs_lower_page_cache =
+ kmem_cache_create("ecryptfs_lower_page_cache", PAGE_CACHE_SIZE,
+ 0, SLAB_HWCACHE_ALIGN, NULL, NULL);
+ if (ecryptfs_lower_page_cache)
+ rc |= ECRYPTFS_LOWER_PAGE_CACHE;
+ else
+ ecryptfs_printk(KERN_WARNING, "ecryptfs_lower_page_cache "
+ "kmem_cache_create failed\n");
+
+ ecryptfs_allocated_caches = rc;
+ rc = ECRYPTFS_CACHE_CREATION_SUCCESS ^ rc;
+ return rc;
+}
+
+/**
+ * ecryptfs_free_kmem_caches
+ *
+ * Returns zero on success; non-zero otherwise
+ */
+static int ecryptfs_free_kmem_caches(void)
+{
+ int rc = 0;
+ int err;
+
+ if (ecryptfs_allocated_caches & ECRYPTFS_AUTH_TOK_LIST_ITEM_CACHE) {
+ rc = kmem_cache_destroy(ecryptfs_auth_tok_list_item_cache);
+ if (rc)
+ ecryptfs_printk(KERN_WARNING,
+ "Not all ecryptfs_auth_tok_"
+ "list_item_cache structures were "
+ "freed\n");
+ }
+ if (ecryptfs_allocated_caches & ECRYPTFS_FILE_INFO_CACHE) {
+ err = kmem_cache_destroy(ecryptfs_file_info_cache);
+ if (err)
+ ecryptfs_printk(KERN_WARNING,
+ "Not all ecryptfs_file_info_"
+ "cache regions were freed\n");
+ rc |= err;
+ }
+ if (ecryptfs_allocated_caches & ECRYPTFS_DENTRY_INFO_CACHE) {
+ err = kmem_cache_destroy(ecryptfs_dentry_info_cache);
+ if (err)
+ ecryptfs_printk(KERN_WARNING,
+ "Not all ecryptfs_dentry_info_"
+ "cache regions were freed\n");
+ rc |= err;
+ }
+ if (ecryptfs_allocated_caches & ECRYPTFS_INODE_INFO_CACHE) {
+ err = kmem_cache_destroy(ecryptfs_inode_info_cache);
+ if (err)
+ ecryptfs_printk(KERN_WARNING,
+ "Not all ecryptfs_inode_info_"
+ "cache regions were freed\n");
+ rc |= err;
+ }
+ if (ecryptfs_allocated_caches & ECRYPTFS_SB_INFO_CACHE) {
+ err = kmem_cache_destroy(ecryptfs_sb_info_cache);
+ if (err)
+ ecryptfs_printk(KERN_WARNING,
+ "Not all ecryptfs_sb_info_"
+ "cache regions were freed\n");
+ rc |= err;
+ }
+ if (ecryptfs_allocated_caches & ECRYPTFS_HEADER_CACHE_0) {
+ err = kmem_cache_destroy(ecryptfs_header_cache_0);
+ if (err)
+ ecryptfs_printk(KERN_WARNING, "Not all ecryptfs_"
+ "header_cache_0 regions were freed\n");
+ rc |= err;
+ }
+ if (ecryptfs_allocated_caches & ECRYPTFS_HEADER_CACHE_1) {
+ err = kmem_cache_destroy(ecryptfs_header_cache_1);
+ if (err)
+ ecryptfs_printk(KERN_WARNING, "Not all ecryptfs_"
+ "header_cache_1 regions were freed\n");
+ rc |= err;
+ }
+ if (ecryptfs_allocated_caches & ECRYPTFS_HEADER_CACHE_2) {
+ err = kmem_cache_destroy(ecryptfs_header_cache_2);
+ if (err)
+ ecryptfs_printk(KERN_WARNING, "Not all ecryptfs_"
+ "header_cache_2 regions were freed\n");
+ rc |= err;
+ }
+ if (ecryptfs_allocated_caches & ECRYPTFS_LOWER_PAGE_CACHE) {
+ err = kmem_cache_destroy(ecryptfs_lower_page_cache);
+ if (err)
+ ecryptfs_printk(KERN_WARNING, "Not all ecryptfs_"
+ "lower_page_cache regions were "
+ "freed\n");
+ rc |= err;
+ }
+ return rc;
+}
+
+static int __init init_ecryptfs_fs(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) {
+ ecryptfs_printk(KERN_EMERG, "Failure occured while "
+ "attempting to create caches [Mask of created "
+ "caches: 0x%x]. Now freeing caches.\n",
+ ecryptfs_allocated_caches);
+ ecryptfs_free_kmem_caches();
+ rc = -ENOMEM;
+ goto out;
+ }
+ ecryptfs_printk(KERN_DEBUG, "Registering eCryptfs\n");
+ rc = register_filesystem(&ecryptfs_fs_type);
+out:
+ return rc;
+}
+
+static void __exit exit_ecryptfs_fs(void)
+{
+ int rc;
+
+ unregister_filesystem(&ecryptfs_fs_type);
+ rc = ecryptfs_free_kmem_caches();
+ if (rc)
+ ecryptfs_printk(KERN_EMERG, "Failure occured while "
+ "attempting to free caches: [%d]\n", rc);
+}
+
+MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>");
+MODULE_DESCRIPTION("eCryptfs");
+
+MODULE_LICENSE("GPL");
+
+module_init(init_ecryptfs_fs)
+module_exit(exit_ecryptfs_fs)