init android origin source code

1 files changed, 1194 insertions, 0 deletions

diff --git a/ANDROID_3.4.5/fs/ecryptfs/inode.c b/ANDROID_3.4.5/fs/ecryptfs/inode.c
new file mode 100644
index 00000000..ab35b113
--- /dev/null
+++ b/ANDROID_3.4.5/fs/ecryptfs/inode.c
@@ -0,0 +1,1194 @@
+/**
+ * eCryptfs: Linux filesystem encryption layer
+ *
+ * Copyright (C) 1997-2004 Erez Zadok
+ * Copyright (C) 2001-2004 Stony Brook University
+ * Copyright (C) 2004-2007 International Business Machines Corp.
+ *   Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
+ *              Michael C. Thompsion <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/file.h>
+#include <linux/vmalloc.h>
+#include <linux/pagemap.h>
+#include <linux/dcache.h>
+#include <linux/namei.h>
+#include <linux/mount.h>
+#include <linux/crypto.h>
+#include <linux/fs_stack.h>
+#include <linux/slab.h>
+#include <linux/xattr.h>
+#include <asm/unaligned.h>
+#include "ecryptfs_kernel.h"
+
+static struct dentry *lock_parent(struct dentry *dentry)
+{
+	struct dentry *dir;
+
+	dir = dget_parent(dentry);
+	mutex_lock_nested(&(dir->d_inode->i_mutex), I_MUTEX_PARENT);
+	return dir;
+}
+
+static void unlock_dir(struct dentry *dir)
+{
+	mutex_unlock(&dir->d_inode->i_mutex);
+	dput(dir);
+}
+
+static int ecryptfs_inode_test(struct inode *inode, void *lower_inode)
+{
+	if (ecryptfs_inode_to_lower(inode) == (struct inode *)lower_inode)
+		return 1;
+	return 0;
+}
+
+static int ecryptfs_inode_set(struct inode *inode, void *opaque)
+{
+	struct inode *lower_inode = opaque;
+
+	ecryptfs_set_inode_lower(inode, lower_inode);
+	fsstack_copy_attr_all(inode, lower_inode);
+	/* i_size will be overwritten for encrypted regular files */
+	fsstack_copy_inode_size(inode, lower_inode);
+	inode->i_ino = lower_inode->i_ino;
+	inode->i_version++;
+	inode->i_mapping->a_ops = &ecryptfs_aops;
+	inode->i_mapping->backing_dev_info = inode->i_sb->s_bdi;
+
+	if (S_ISLNK(inode->i_mode))
+		inode->i_op = &ecryptfs_symlink_iops;
+	else if (S_ISDIR(inode->i_mode))
+		inode->i_op = &ecryptfs_dir_iops;
+	else
+		inode->i_op = &ecryptfs_main_iops;
+
+	if (S_ISDIR(inode->i_mode))
+		inode->i_fop = &ecryptfs_dir_fops;
+	else if (special_file(inode->i_mode))
+		init_special_inode(inode, inode->i_mode, inode->i_rdev);
+	else
+		inode->i_fop = &ecryptfs_main_fops;
+
+	return 0;
+}
+
+static struct inode *__ecryptfs_get_inode(struct inode *lower_inode,
+					  struct super_block *sb)
+{
+	struct inode *inode;
+
+	if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb))
+		return ERR_PTR(-EXDEV);
+	if (!igrab(lower_inode))
+		return ERR_PTR(-ESTALE);
+	inode = iget5_locked(sb, (unsigned long)lower_inode,
+			     ecryptfs_inode_test, ecryptfs_inode_set,
+			     lower_inode);
+	if (!inode) {
+		iput(lower_inode);
+		return ERR_PTR(-EACCES);
+	}
+	if (!(inode->i_state & I_NEW))
+		iput(lower_inode);
+
+	return inode;
+}
+
+struct inode *ecryptfs_get_inode(struct inode *lower_inode,
+				 struct super_block *sb)
+{
+	struct inode *inode = __ecryptfs_get_inode(lower_inode, sb);
+
+	if (!IS_ERR(inode) && (inode->i_state & I_NEW))
+		unlock_new_inode(inode);
+
+	return inode;
+}
+
+/**
+ * ecryptfs_interpose
+ * @lower_dentry: Existing dentry in the lower filesystem
+ * @dentry: ecryptfs' dentry
+ * @sb: ecryptfs's super_block
+ *
+ * Interposes upper and lower dentries.
+ *
+ * Returns zero on success; non-zero otherwise
+ */
+static int ecryptfs_interpose(struct dentry *lower_dentry,
+			      struct dentry *dentry, struct super_block *sb)
+{
+	struct inode *inode = ecryptfs_get_inode(lower_dentry->d_inode, sb);
+
+	if (IS_ERR(inode))
+		return PTR_ERR(inode);
+	d_instantiate(dentry, inode);
+
+	return 0;
+}
+
+/**
+ * ecryptfs_do_create
+ * @directory_inode: inode of the new file's dentry's parent in ecryptfs
+ * @ecryptfs_dentry: New file's dentry in ecryptfs
+ * @mode: The mode of the new file
+ * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
+ *
+ * Creates the underlying file and the eCryptfs inode which will link to
+ * it. It will also update the eCryptfs directory inode to mimic the
+ * stat of the lower directory inode.
+ *
+ * Returns the new eCryptfs inode on success; an ERR_PTR on error condition
+ */
+static struct inode *
+ecryptfs_do_create(struct inode *directory_inode,
+		   struct dentry *ecryptfs_dentry, umode_t mode)
+{
+	int rc;
+	struct dentry *lower_dentry;
+	struct dentry *lower_dir_dentry;
+	struct inode *inode;
+
+	lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
+	lower_dir_dentry = lock_parent(lower_dentry);
+	if (IS_ERR(lower_dir_dentry)) {
+		ecryptfs_printk(KERN_ERR, "Error locking directory of "
+				"dentry\n");
+		inode = ERR_CAST(lower_dir_dentry);
+		goto out;
+	}
+	rc = vfs_create(lower_dir_dentry->d_inode, lower_dentry, mode, NULL);
+	if (rc) {
+		printk(KERN_ERR "%s: Failure to create dentry in lower fs; "
+		       "rc = [%d]\n", __func__, rc);
+		inode = ERR_PTR(rc);
+		goto out_lock;
+	}
+	inode = __ecryptfs_get_inode(lower_dentry->d_inode,
+				     directory_inode->i_sb);
+	if (IS_ERR(inode))
+		goto out_lock;
+	fsstack_copy_attr_times(directory_inode, lower_dir_dentry->d_inode);
+	fsstack_copy_inode_size(directory_inode, lower_dir_dentry->d_inode);
+out_lock:
+	unlock_dir(lower_dir_dentry);
+out:
+	return inode;
+}
+
+/**
+ * ecryptfs_initialize_file
+ *
+ * Cause the file to be changed from a basic empty file to an ecryptfs
+ * file with a header and first data page.
+ *
+ * Returns zero on success
+ */
+static int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry,
+				    struct inode *ecryptfs_inode)
+{
+	struct ecryptfs_crypt_stat *crypt_stat =
+		&ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat;
+	int rc = 0;
+
+	if (S_ISDIR(ecryptfs_inode->i_mode)) {
+		ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
+		crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
+		goto out;
+	}
+	ecryptfs_printk(KERN_DEBUG, "Initializing crypto context\n");
+	rc = ecryptfs_new_file_context(ecryptfs_inode);
+	if (rc) {
+		ecryptfs_printk(KERN_ERR, "Error creating new file "
+				"context; rc = [%d]\n", rc);
+		goto out;
+	}
+	rc = ecryptfs_get_lower_file(ecryptfs_dentry, ecryptfs_inode);
+	if (rc) {
+		printk(KERN_ERR "%s: Error attempting to initialize "
+			"the lower file for the dentry with name "
+			"[%s]; rc = [%d]\n", __func__,
+			ecryptfs_dentry->d_name.name, rc);
+		goto out;
+	}
+	rc = ecryptfs_write_metadata(ecryptfs_dentry, ecryptfs_inode);
+	if (rc)
+		printk(KERN_ERR "Error writing headers; rc = [%d]\n", rc);
+	ecryptfs_put_lower_file(ecryptfs_inode);
+out:
+	return rc;
+}
+
+/**
+ * ecryptfs_create
+ * @dir: The inode of the directory in which to create the file.
+ * @dentry: The eCryptfs dentry
+ * @mode: The mode of the new file.
+ * @nd: nameidata
+ *
+ * Creates a new file.
+ *
+ * Returns zero on success; non-zero on error condition
+ */
+static int
+ecryptfs_create(struct inode *directory_inode, struct dentry *ecryptfs_dentry,
+		umode_t mode, struct nameidata *nd)
+{
+	struct inode *ecryptfs_inode;
+	int rc;
+
+	ecryptfs_inode = ecryptfs_do_create(directory_inode, ecryptfs_dentry,
+					    mode);
+	if (unlikely(IS_ERR(ecryptfs_inode))) {
+		ecryptfs_printk(KERN_WARNING, "Failed to create file in"
+				"lower filesystem\n");
+		rc = PTR_ERR(ecryptfs_inode);
+		goto out;
+	}
+	/* At this point, a file exists on "disk"; we need to make sure
+	 * that this on disk file is prepared to be an ecryptfs file */
+	rc = ecryptfs_initialize_file(ecryptfs_dentry, ecryptfs_inode);
+	if (rc) {
+		drop_nlink(ecryptfs_inode);
+		unlock_new_inode(ecryptfs_inode);
+		iput(ecryptfs_inode);
+		goto out;
+	}
+	d_instantiate(ecryptfs_dentry, ecryptfs_inode);
+	unlock_new_inode(ecryptfs_inode);
+out:
+	return rc;
+}
+
+static int ecryptfs_i_size_read(struct dentry *dentry, struct inode *inode)
+{
+	struct ecryptfs_crypt_stat *crypt_stat;
+	int rc;
+
+	rc = ecryptfs_get_lower_file(dentry, inode);
+	if (rc) {
+		printk(KERN_ERR "%s: Error attempting to initialize "
+			"the lower file for the dentry with name "
+			"[%s]; rc = [%d]\n", __func__,
+			dentry->d_name.name, rc);
+		return rc;
+	}
+
+	crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
+	/* TODO: lock for crypt_stat comparison */
+	if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED))
+		ecryptfs_set_default_sizes(crypt_stat);
+
+	rc = ecryptfs_read_and_validate_header_region(inode);
+	ecryptfs_put_lower_file(inode);
+	if (rc) {
+		rc = ecryptfs_read_and_validate_xattr_region(dentry, inode);
+		if (!rc)
+			crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
+	}
+
+	/* Must return 0 to allow non-eCryptfs files to be looked up, too */
+	return 0;
+}
+
+/**
+ * ecryptfs_lookup_interpose - Dentry interposition for a lookup
+ */
+static int ecryptfs_lookup_interpose(struct dentry *dentry,
+				     struct dentry *lower_dentry,
+				     struct inode *dir_inode)
+{
+	struct inode *inode, *lower_inode = lower_dentry->d_inode;
+	struct ecryptfs_dentry_info *dentry_info;
+	struct vfsmount *lower_mnt;
+	int rc = 0;
+
+	lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(dentry->d_parent));
+	fsstack_copy_attr_atime(dir_inode, lower_dentry->d_parent->d_inode);
+	BUG_ON(!lower_dentry->d_count);
+
+	dentry_info = kmem_cache_alloc(ecryptfs_dentry_info_cache, GFP_KERNEL);
+	ecryptfs_set_dentry_private(dentry, dentry_info);
+	if (!dentry_info) {
+		printk(KERN_ERR "%s: Out of memory whilst attempting "
+		       "to allocate ecryptfs_dentry_info struct\n",
+			__func__);
+		dput(lower_dentry);
+		mntput(lower_mnt);
+		d_drop(dentry);
+		return -ENOMEM;
+	}
+	ecryptfs_set_dentry_lower(dentry, lower_dentry);
+	ecryptfs_set_dentry_lower_mnt(dentry, lower_mnt);
+
+	if (!lower_dentry->d_inode) {
+		/* We want to add because we couldn't find in lower */
+		d_add(dentry, NULL);
+		return 0;
+	}
+	inode = __ecryptfs_get_inode(lower_inode, dir_inode->i_sb);
+	if (IS_ERR(inode)) {
+		printk(KERN_ERR "%s: Error interposing; rc = [%ld]\n",
+		       __func__, PTR_ERR(inode));
+		return PTR_ERR(inode);
+	}
+	if (S_ISREG(inode->i_mode)) {
+		rc = ecryptfs_i_size_read(dentry, inode);
+		if (rc) {
+			make_bad_inode(inode);
+			return rc;
+		}
+	}
+
+	if (inode->i_state & I_NEW)
+		unlock_new_inode(inode);
+	d_add(dentry, inode);
+
+	return rc;
+}
+
+/**
+ * ecryptfs_lookup
+ * @ecryptfs_dir_inode: The eCryptfs directory inode
+ * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
+ * @ecryptfs_nd: nameidata; may be NULL
+ *
+ * Find a file on disk. If the file does not exist, then we'll add it to the
+ * dentry cache and continue on to read it from the disk.
+ */
+static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
+				      struct dentry *ecryptfs_dentry,
+				      struct nameidata *ecryptfs_nd)
+{
+	char *encrypted_and_encoded_name = NULL;
+	size_t encrypted_and_encoded_name_size;
+	struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
+	struct dentry *lower_dir_dentry, *lower_dentry;
+	int rc = 0;
+
+	if ((ecryptfs_dentry->d_name.len == 1
+	     && !strcmp(ecryptfs_dentry->d_name.name, "."))
+	    || (ecryptfs_dentry->d_name.len == 2
+		&& !strcmp(ecryptfs_dentry->d_name.name, ".."))) {
+		goto out_d_drop;
+	}
+	lower_dir_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry->d_parent);
+	mutex_lock(&lower_dir_dentry->d_inode->i_mutex);
+	lower_dentry = lookup_one_len(ecryptfs_dentry->d_name.name,
+				      lower_dir_dentry,
+				      ecryptfs_dentry->d_name.len);
+	mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
+	if (IS_ERR(lower_dentry)) {
+		rc = PTR_ERR(lower_dentry);
+		ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
+				"[%d] on lower_dentry = [%s]\n", __func__, rc,
+				encrypted_and_encoded_name);
+		goto out_d_drop;
+	}
+	if (lower_dentry->d_inode)
+		goto interpose;
+	mount_crypt_stat = &ecryptfs_superblock_to_private(
+				ecryptfs_dentry->d_sb)->mount_crypt_stat;
+	if (!(mount_crypt_stat
+	    && (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)))
+		goto interpose;
+	dput(lower_dentry);
+	rc = ecryptfs_encrypt_and_encode_filename(
+		&encrypted_and_encoded_name, &encrypted_and_encoded_name_size,
+		NULL, mount_crypt_stat, ecryptfs_dentry->d_name.name,
+		ecryptfs_dentry->d_name.len);
+	if (rc) {
+		printk(KERN_ERR "%s: Error attempting to encrypt and encode "
+		       "filename; rc = [%d]\n", __func__, rc);
+		goto out_d_drop;
+	}
+	mutex_lock(&lower_dir_dentry->d_inode->i_mutex);
+	lower_dentry = lookup_one_len(encrypted_and_encoded_name,
+				      lower_dir_dentry,
+				      encrypted_and_encoded_name_size);
+	mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
+	if (IS_ERR(lower_dentry)) {
+		rc = PTR_ERR(lower_dentry);
+		ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
+				"[%d] on lower_dentry = [%s]\n", __func__, rc,
+				encrypted_and_encoded_name);
+		goto out_d_drop;
+	}
+interpose:
+	rc = ecryptfs_lookup_interpose(ecryptfs_dentry, lower_dentry,
+				       ecryptfs_dir_inode);
+	goto out;
+out_d_drop:
+	d_drop(ecryptfs_dentry);
+out:
+	kfree(encrypted_and_encoded_name);
+	return ERR_PTR(rc);
+}
+
+static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
+			 struct dentry *new_dentry)
+{
+	struct dentry *lower_old_dentry;
+	struct dentry *lower_new_dentry;
+	struct dentry *lower_dir_dentry;
+	u64 file_size_save;
+	int rc;
+
+	file_size_save = i_size_read(old_dentry->d_inode);
+	lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
+	lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
+	dget(lower_old_dentry);
+	dget(lower_new_dentry);
+	lower_dir_dentry = lock_parent(lower_new_dentry);
+	rc = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode,
+		      lower_new_dentry);
+	if (rc || !lower_new_dentry->d_inode)
+		goto out_lock;
+	rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb);
+	if (rc)
+		goto out_lock;
+	fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
+	fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
+	set_nlink(old_dentry->d_inode,
+		  ecryptfs_inode_to_lower(old_dentry->d_inode)->i_nlink);
+	i_size_write(new_dentry->d_inode, file_size_save);
+out_lock:
+	unlock_dir(lower_dir_dentry);
+	dput(lower_new_dentry);
+	dput(lower_old_dentry);
+	return rc;
+}
+
+static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
+{
+	int rc = 0;
+	struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
+	struct inode *lower_dir_inode = ecryptfs_inode_to_lower(dir);
+	struct dentry *lower_dir_dentry;
+
+	dget(lower_dentry);
+	lower_dir_dentry = lock_parent(lower_dentry);
+	rc = vfs_unlink(lower_dir_inode, lower_dentry);
+	if (rc) {
+		printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc);
+		goto out_unlock;
+	}
+	fsstack_copy_attr_times(dir, lower_dir_inode);
+	set_nlink(dentry->d_inode,
+		  ecryptfs_inode_to_lower(dentry->d_inode)->i_nlink);
+	dentry->d_inode->i_ctime = dir->i_ctime;
+	d_drop(dentry);
+out_unlock:
+	unlock_dir(lower_dir_dentry);
+	dput(lower_dentry);
+	return rc;
+}
+
+static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry,
+			    const char *symname)
+{
+	int rc;
+	struct dentry *lower_dentry;
+	struct dentry *lower_dir_dentry;
+	char *encoded_symname;
+	size_t encoded_symlen;
+	struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
+
+	lower_dentry = ecryptfs_dentry_to_lower(dentry);
+	dget(lower_dentry);
+	lower_dir_dentry = lock_parent(lower_dentry);
+	mount_crypt_stat = &ecryptfs_superblock_to_private(
+		dir->i_sb)->mount_crypt_stat;
+	rc = ecryptfs_encrypt_and_encode_filename(&encoded_symname,
+						  &encoded_symlen,
+						  NULL,
+						  mount_crypt_stat, symname,
+						  strlen(symname));
+	if (rc)
+		goto out_lock;
+	rc = vfs_symlink(lower_dir_dentry->d_inode, lower_dentry,
+			 encoded_symname);
+	kfree(encoded_symname);
+	if (rc || !lower_dentry->d_inode)
+		goto out_lock;
+	rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
+	if (rc)
+		goto out_lock;
+	fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
+	fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
+out_lock:
+	unlock_dir(lower_dir_dentry);
+	dput(lower_dentry);
+	if (!dentry->d_inode)
+		d_drop(dentry);
+	return rc;
+}
+
+static int ecryptfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
+{
+	int rc;
+	struct dentry *lower_dentry;
+	struct dentry *lower_dir_dentry;
+
+	lower_dentry = ecryptfs_dentry_to_lower(dentry);
+	lower_dir_dentry = lock_parent(lower_dentry);
+	rc = vfs_mkdir(lower_dir_dentry->d_inode, lower_dentry, mode);
+	if (rc || !lower_dentry->d_inode)
+		goto out;
+	rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
+	if (rc)
+		goto out;
+	fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
+	fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
+	set_nlink(dir, lower_dir_dentry->d_inode->i_nlink);
+out:
+	unlock_dir(lower_dir_dentry);
+	if (!dentry->d_inode)
+		d_drop(dentry);
+	return rc;
+}
+
+static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
+{
+	struct dentry *lower_dentry;
+	struct dentry *lower_dir_dentry;
+	int rc;
+
+	lower_dentry = ecryptfs_dentry_to_lower(dentry);
+	dget(dentry);
+	lower_dir_dentry = lock_parent(lower_dentry);
+	dget(lower_dentry);
+	rc = vfs_rmdir(lower_dir_dentry->d_inode, lower_dentry);
+	dput(lower_dentry);
+	if (!rc && dentry->d_inode)
+		clear_nlink(dentry->d_inode);
+	fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
+	set_nlink(dir, lower_dir_dentry->d_inode->i_nlink);
+	unlock_dir(lower_dir_dentry);
+	if (!rc)
+		d_drop(dentry);
+	dput(dentry);
+	return rc;
+}
+
+static int
+ecryptfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
+{
+	int rc;
+	struct dentry *lower_dentry;
+	struct dentry *lower_dir_dentry;
+
+	lower_dentry = ecryptfs_dentry_to_lower(dentry);
+	lower_dir_dentry = lock_parent(lower_dentry);
+	rc = vfs_mknod(lower_dir_dentry->d_inode, lower_dentry, mode, dev);
+	if (rc || !lower_dentry->d_inode)
+		goto out;
+	rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
+	if (rc)
+		goto out;
+	fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
+	fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
+out:
+	unlock_dir(lower_dir_dentry);
+	if (!dentry->d_inode)
+		d_drop(dentry);
+	return rc;
+}
+
+static int
+ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
+		struct inode *new_dir, struct dentry *new_dentry)
+{
+	int rc;
+	struct dentry *lower_old_dentry;
+	struct dentry *lower_new_dentry;
+	struct dentry *lower_old_dir_dentry;
+	struct dentry *lower_new_dir_dentry;
+	struct dentry *trap = NULL;
+
+	lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
+	lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
+	dget(lower_old_dentry);
+	dget(lower_new_dentry);
+	lower_old_dir_dentry = dget_parent(lower_old_dentry);
+	lower_new_dir_dentry = dget_parent(lower_new_dentry);
+	trap = lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
+	/* source should not be ancestor of target */
+	if (trap == lower_old_dentry) {
+		rc = -EINVAL;
+		goto out_lock;
+	}
+	/* target should not be ancestor of source */
+	if (trap == lower_new_dentry) {
+		rc = -ENOTEMPTY;
+		goto out_lock;
+	}
+	rc = vfs_rename(lower_old_dir_dentry->d_inode, lower_old_dentry,
+			lower_new_dir_dentry->d_inode, lower_new_dentry);
+	if (rc)
+		goto out_lock;
+	fsstack_copy_attr_all(new_dir, lower_new_dir_dentry->d_inode);
+	if (new_dir != old_dir)
+		fsstack_copy_attr_all(old_dir, lower_old_dir_dentry->d_inode);
+out_lock:
+	unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
+	dput(lower_new_dir_dentry);
+	dput(lower_old_dir_dentry);
+	dput(lower_new_dentry);
+	dput(lower_old_dentry);
+	return rc;
+}
+
+static int ecryptfs_readlink_lower(struct dentry *dentry, char **buf,
+				   size_t *bufsiz)
+{
+	struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
+	char *lower_buf;
+	size_t lower_bufsiz = PATH_MAX;
+	mm_segment_t old_fs;
+	int rc;
+
+	lower_buf = kmalloc(lower_bufsiz, GFP_KERNEL);
+	if (!lower_buf) {
+		rc = -ENOMEM;
+		goto out;
+	}
+	old_fs = get_fs();
+	set_fs(get_ds());
+	rc = lower_dentry->d_inode->i_op->readlink(lower_dentry,
+						   (char __user *)lower_buf,
+						   lower_bufsiz);
+	set_fs(old_fs);
+	if (rc < 0)
+		goto out;
+	lower_bufsiz = rc;
+	rc = ecryptfs_decode_and_decrypt_filename(buf, bufsiz, dentry,
+						  lower_buf, lower_bufsiz);
+out:
+	kfree(lower_buf);
+	return rc;
+}
+
+static int
+ecryptfs_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
+{
+	char *kbuf;
+	size_t kbufsiz, copied;
+	int rc;
+
+	rc = ecryptfs_readlink_lower(dentry, &kbuf, &kbufsiz);
+	if (rc)
+		goto out;
+	copied = min_t(size_t, bufsiz, kbufsiz);
+	rc = copy_to_user(buf, kbuf, copied) ? -EFAULT : copied;
+	kfree(kbuf);
+	fsstack_copy_attr_atime(dentry->d_inode,
+				ecryptfs_dentry_to_lower(dentry)->d_inode);
+out:
+	return rc;
+}
+
+static void *ecryptfs_follow_link(struct dentry *dentry, struct nameidata *nd)
+{
+	char *buf;
+	int len = PAGE_SIZE, rc;
+	mm_segment_t old_fs;
+
+	/* Released in ecryptfs_put_link(); only release here on error */
+	buf = kmalloc(len, GFP_KERNEL);
+	if (!buf) {
+		buf = ERR_PTR(-ENOMEM);
+		goto out;
+	}
+	old_fs = get_fs();
+	set_fs(get_ds());
+	rc = dentry->d_inode->i_op->readlink(dentry, (char __user *)buf, len);
+	set_fs(old_fs);
+	if (rc < 0) {
+		kfree(buf);
+		buf = ERR_PTR(rc);
+	} else
+		buf[rc] = '\0';
+out:
+	nd_set_link(nd, buf);
+	return NULL;
+}
+
+static void
+ecryptfs_put_link(struct dentry *dentry, struct nameidata *nd, void *ptr)
+{
+	char *buf = nd_get_link(nd);
+	if (!IS_ERR(buf)) {
+		/* Free the char* */
+		kfree(buf);
+	}
+}
+
+/**
+ * upper_size_to_lower_size
+ * @crypt_stat: Crypt_stat associated with file
+ * @upper_size: Size of the upper file
+ *
+ * Calculate the required size of the lower file based on the
+ * specified size of the upper file. This calculation is based on the
+ * number of headers in the underlying file and the extent size.
+ *
+ * Returns Calculated size of the lower file.
+ */
+static loff_t
+upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
+			 loff_t upper_size)
+{
+	loff_t lower_size;
+
+	lower_size = ecryptfs_lower_header_size(crypt_stat);
+	if (upper_size != 0) {
+		loff_t num_extents;
+
+		num_extents = upper_size >> crypt_stat->extent_shift;
+		if (upper_size & ~crypt_stat->extent_mask)
+			num_extents++;
+		lower_size += (num_extents * crypt_stat->extent_size);
+	}
+	return lower_size;
+}
+
+/**
+ * truncate_upper
+ * @dentry: The ecryptfs layer dentry
+ * @ia: Address of the ecryptfs inode's attributes
+ * @lower_ia: Address of the lower inode's attributes
+ *
+ * Function to handle truncations modifying the size of the file. Note
+ * that the file sizes are interpolated. When expanding, we are simply
+ * writing strings of 0's out. When truncating, we truncate the upper
+ * inode and update the lower_ia according to the page index
+ * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
+ * the caller must use lower_ia in a call to notify_change() to perform
+ * the truncation of the lower inode.
+ *
+ * Returns zero on success; non-zero otherwise
+ */
+static int truncate_upper(struct dentry *dentry, struct iattr *ia,
+			  struct iattr *lower_ia)
+{
+	int rc = 0;
+	struct inode *inode = dentry->d_inode;
+	struct ecryptfs_crypt_stat *crypt_stat;
+	loff_t i_size = i_size_read(inode);
+	loff_t lower_size_before_truncate;
+	loff_t lower_size_after_truncate;
+
+	if (unlikely((ia->ia_size == i_size))) {
+		lower_ia->ia_valid &= ~ATTR_SIZE;
+		return 0;
+	}
+	rc = ecryptfs_get_lower_file(dentry, inode);
+	if (rc)
+		return rc;
+	crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
+	/* Switch on growing or shrinking file */
+	if (ia->ia_size > i_size) {
+		char zero[] = { 0x00 };
+
+		lower_ia->ia_valid &= ~ATTR_SIZE;
+		/* Write a single 0 at the last position of the file;
+		 * this triggers code that will fill in 0's throughout
+		 * the intermediate portion of the previous end of the
+		 * file and the new and of the file */
+		rc = ecryptfs_write(inode, zero,
+				    (ia->ia_size - 1), 1);
+	} else { /* ia->ia_size < i_size_read(inode) */
+		/* We're chopping off all the pages down to the page
+		 * in which ia->ia_size is located. Fill in the end of
+		 * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
+		 * PAGE_CACHE_SIZE with zeros. */
+		size_t num_zeros = (PAGE_CACHE_SIZE
+				    - (ia->ia_size & ~PAGE_CACHE_MASK));
+
+		if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
+			truncate_setsize(inode, ia->ia_size);
+			lower_ia->ia_size = ia->ia_size;
+			lower_ia->ia_valid |= ATTR_SIZE;
+			goto out;
+		}
+		if (num_zeros) {
+			char *zeros_virt;
+
+			zeros_virt = kzalloc(num_zeros, GFP_KERNEL);
+			if (!zeros_virt) {
+				rc = -ENOMEM;
+				goto out;
+			}
+			rc = ecryptfs_write(inode, zeros_virt,
+					    ia->ia_size, num_zeros);
+			kfree(zeros_virt);
+			if (rc) {
+				printk(KERN_ERR "Error attempting to zero out "
+				       "the remainder of the end page on "
+				       "reducing truncate; rc = [%d]\n", rc);
+				goto out;
+			}
+		}
+		truncate_setsize(inode, ia->ia_size);
+		rc = ecryptfs_write_inode_size_to_metadata(inode);
+		if (rc) {
+			printk(KERN_ERR	"Problem with "
+			       "ecryptfs_write_inode_size_to_metadata; "
+			       "rc = [%d]\n", rc);
+			goto out;
+		}
+		/* We are reducing the size of the ecryptfs file, and need to
+		 * know if we need to reduce the size of the lower file. */
+		lower_size_before_truncate =
+		    upper_size_to_lower_size(crypt_stat, i_size);
+		lower_size_after_truncate =
+		    upper_size_to_lower_size(crypt_stat, ia->ia_size);
+		if (lower_size_after_truncate < lower_size_before_truncate) {
+			lower_ia->ia_size = lower_size_after_truncate;
+			lower_ia->ia_valid |= ATTR_SIZE;
+		} else
+			lower_ia->ia_valid &= ~ATTR_SIZE;
+	}
+out:
+	ecryptfs_put_lower_file(inode);
+	return rc;
+}
+
+static int ecryptfs_inode_newsize_ok(struct inode *inode, loff_t offset)
+{
+	struct ecryptfs_crypt_stat *crypt_stat;
+	loff_t lower_oldsize, lower_newsize;
+
+	crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
+	lower_oldsize = upper_size_to_lower_size(crypt_stat,
+						 i_size_read(inode));
+	lower_newsize = upper_size_to_lower_size(crypt_stat, offset);
+	if (lower_newsize > lower_oldsize) {
+		/*
+		 * The eCryptfs inode and the new *lower* size are mixed here
+		 * because we may not have the lower i_mutex held and/or it may
+		 * not be appropriate to call inode_newsize_ok() with inodes
+		 * from other filesystems.
+		 */
+		return inode_newsize_ok(inode, lower_newsize);
+	}
+
+	return 0;
+}
+
+/**
+ * ecryptfs_truncate
+ * @dentry: The ecryptfs layer dentry
+ * @new_length: The length to expand the file to
+ *
+ * Simple function that handles the truncation of an eCryptfs inode and
+ * its corresponding lower inode.
+ *
+ * Returns zero on success; non-zero otherwise
+ */
+int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
+{
+	struct iattr ia = { .ia_valid = ATTR_SIZE, .ia_size = new_length };
+	struct iattr lower_ia = { .ia_valid = 0 };
+	int rc;
+
+	rc = ecryptfs_inode_newsize_ok(dentry->d_inode, new_length);
+	if (rc)
+		return rc;
+
+	rc = truncate_upper(dentry, &ia, &lower_ia);
+	if (!rc && lower_ia.ia_valid & ATTR_SIZE) {
+		struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
+
+		mutex_lock(&lower_dentry->d_inode->i_mutex);
+		rc = notify_change(lower_dentry, &lower_ia);
+		mutex_unlock(&lower_dentry->d_inode->i_mutex);
+	}
+	return rc;
+}
+
+static int
+ecryptfs_permission(struct inode *inode, int mask)
+{
+	return inode_permission(ecryptfs_inode_to_lower(inode), mask);
+}
+
+/**
+ * ecryptfs_setattr
+ * @dentry: dentry handle to the inode to modify
+ * @ia: Structure with flags of what to change and values
+ *
+ * Updates the metadata of an inode. If the update is to the size
+ * i.e. truncation, then ecryptfs_truncate will handle the size modification
+ * of both the ecryptfs inode and the lower inode.
+ *
+ * All other metadata changes will be passed right to the lower filesystem,
+ * and we will just update our inode to look like the lower.
+ */
+static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
+{
+	int rc = 0;
+	struct dentry *lower_dentry;
+	struct iattr lower_ia;
+	struct inode *inode;
+	struct inode *lower_inode;
+	struct ecryptfs_crypt_stat *crypt_stat;
+
+	crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
+	if (!(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED))
+		ecryptfs_init_crypt_stat(crypt_stat);
+	inode = dentry->d_inode;
+	lower_inode = ecryptfs_inode_to_lower(inode);
+	lower_dentry = ecryptfs_dentry_to_lower(dentry);
+	mutex_lock(&crypt_stat->cs_mutex);
+	if (S_ISDIR(dentry->d_inode->i_mode))
+		crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
+	else if (S_ISREG(dentry->d_inode->i_mode)
+		 && (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
+		     || !(crypt_stat->flags & ECRYPTFS_KEY_VALID))) {
+		struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
+
+		mount_crypt_stat = &ecryptfs_superblock_to_private(
+			dentry->d_sb)->mount_crypt_stat;
+		rc = ecryptfs_get_lower_file(dentry, inode);
+		if (rc) {
+			mutex_unlock(&crypt_stat->cs_mutex);
+			goto out;
+		}
+		rc = ecryptfs_read_metadata(dentry);
+		ecryptfs_put_lower_file(inode);
+		if (rc) {
+			if (!(mount_crypt_stat->flags
+			      & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
+				rc = -EIO;
+				printk(KERN_WARNING "Either the lower file "
+				       "is not in a valid eCryptfs format, "
+				       "or the key could not be retrieved. "
+				       "Plaintext passthrough mode is not "
+				       "enabled; returning -EIO\n");
+				mutex_unlock(&crypt_stat->cs_mutex);
+				goto out;
+			}
+			rc = 0;
+			crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED
+					       | ECRYPTFS_ENCRYPTED);
+		}
+	}
+	mutex_unlock(&crypt_stat->cs_mutex);
+
+	rc = inode_change_ok(inode, ia);
+	if (rc)
+		goto out;
+	if (ia->ia_valid & ATTR_SIZE) {
+		rc = ecryptfs_inode_newsize_ok(inode, ia->ia_size);
+		if (rc)
+			goto out;
+	}
+
+	if (S_ISREG(inode->i_mode)) {
+		rc = filemap_write_and_wait(inode->i_mapping);
+		if (rc)
+			goto out;
+		fsstack_copy_attr_all(inode, lower_inode);
+	}
+	memcpy(&lower_ia, ia, sizeof(lower_ia));
+	if (ia->ia_valid & ATTR_FILE)
+		lower_ia.ia_file = ecryptfs_file_to_lower(ia->ia_file);
+	if (ia->ia_valid & ATTR_SIZE) {
+		rc = truncate_upper(dentry, ia, &lower_ia);
+		if (rc < 0)
+			goto out;
+	}
+
+	/*
+	 * mode change is for clearing setuid/setgid bits. Allow lower fs
+	 * to interpret this in its own way.
+	 */
+	if (lower_ia.ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
+		lower_ia.ia_valid &= ~ATTR_MODE;
+
+	mutex_lock(&lower_dentry->d_inode->i_mutex);
+	rc = notify_change(lower_dentry, &lower_ia);
+	mutex_unlock(&lower_dentry->d_inode->i_mutex);
+out:
+	fsstack_copy_attr_all(inode, lower_inode);
+	return rc;
+}
+
+int ecryptfs_getattr_link(struct vfsmount *mnt, struct dentry *dentry,
+			  struct kstat *stat)
+{
+	struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
+	int rc = 0;
+
+	mount_crypt_stat = &ecryptfs_superblock_to_private(
+						dentry->d_sb)->mount_crypt_stat;
+	generic_fillattr(dentry->d_inode, stat);
+	if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) {
+		char *target;
+		size_t targetsiz;
+
+		rc = ecryptfs_readlink_lower(dentry, &target, &targetsiz);
+		if (!rc) {
+			kfree(target);
+			stat->size = targetsiz;
+		}
+	}
+	return rc;
+}
+
+int ecryptfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
+		     struct kstat *stat)
+{
+	struct kstat lower_stat;
+	int rc;
+
+	rc = vfs_getattr(ecryptfs_dentry_to_lower_mnt(dentry),
+			 ecryptfs_dentry_to_lower(dentry), &lower_stat);
+	if (!rc) {
+		fsstack_copy_attr_all(dentry->d_inode,
+				      ecryptfs_inode_to_lower(dentry->d_inode));
+		generic_fillattr(dentry->d_inode, stat);
+		stat->blocks = lower_stat.blocks;
+	}
+	return rc;
+}
+
+int
+ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value,
+		  size_t size, int flags)
+{
+	int rc = 0;
+	struct dentry *lower_dentry;
+
+	lower_dentry = ecryptfs_dentry_to_lower(dentry);
+	if (!lower_dentry->d_inode->i_op->setxattr) {
+		rc = -EOPNOTSUPP;
+		goto out;
+	}
+
+	rc = vfs_setxattr(lower_dentry, name, value, size, flags);
+	if (!rc)
+		fsstack_copy_attr_all(dentry->d_inode, lower_dentry->d_inode);
+out:
+	return rc;
+}
+
+ssize_t
+ecryptfs_getxattr_lower(struct dentry *lower_dentry, const char *name,
+			void *value, size_t size)
+{
+	int rc = 0;
+
+	if (!lower_dentry->d_inode->i_op->getxattr) {
+		rc = -EOPNOTSUPP;
+		goto out;
+	}
+	mutex_lock(&lower_dentry->d_inode->i_mutex);
+	rc = lower_dentry->d_inode->i_op->getxattr(lower_dentry, name, value,
+						   size);
+	mutex_unlock(&lower_dentry->d_inode->i_mutex);
+out:
+	return rc;
+}
+
+static ssize_t
+ecryptfs_getxattr(struct dentry *dentry, const char *name, void *value,
+		  size_t size)
+{
+	return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry), name,
+				       value, size);
+}
+
+static ssize_t
+ecryptfs_listxattr(struct dentry *dentry, char *list, size_t size)
+{
+	int rc = 0;
+	struct dentry *lower_dentry;
+
+	lower_dentry = ecryptfs_dentry_to_lower(dentry);
+	if (!lower_dentry->d_inode->i_op->listxattr) {
+		rc = -EOPNOTSUPP;
+		goto out;
+	}
+	mutex_lock(&lower_dentry->d_inode->i_mutex);
+	rc = lower_dentry->d_inode->i_op->listxattr(lower_dentry, list, size);
+	mutex_unlock(&lower_dentry->d_inode->i_mutex);
+out:
+	return rc;
+}
+
+static int ecryptfs_removexattr(struct dentry *dentry, const char *name)
+{
+	int rc = 0;
+	struct dentry *lower_dentry;
+
+	lower_dentry = ecryptfs_dentry_to_lower(dentry);
+	if (!lower_dentry->d_inode->i_op->removexattr) {
+		rc = -EOPNOTSUPP;
+		goto out;
+	}
+	mutex_lock(&lower_dentry->d_inode->i_mutex);
+	rc = lower_dentry->d_inode->i_op->removexattr(lower_dentry, name);
+	mutex_unlock(&lower_dentry->d_inode->i_mutex);
+out:
+	return rc;
+}
+
+const struct inode_operations ecryptfs_symlink_iops = {
+	.readlink = ecryptfs_readlink,
+	.follow_link = ecryptfs_follow_link,
+	.put_link = ecryptfs_put_link,
+	.permission = ecryptfs_permission,
+	.setattr = ecryptfs_setattr,
+	.getattr = ecryptfs_getattr_link,
+	.setxattr = ecryptfs_setxattr,
+	.getxattr = ecryptfs_getxattr,
+	.listxattr = ecryptfs_listxattr,
+	.removexattr = ecryptfs_removexattr
+};
+
+const struct inode_operations ecryptfs_dir_iops = {
+	.create = ecryptfs_create,
+	.lookup = ecryptfs_lookup,
+	.link = ecryptfs_link,
+	.unlink = ecryptfs_unlink,
+	.symlink = ecryptfs_symlink,
+	.mkdir = ecryptfs_mkdir,
+	.rmdir = ecryptfs_rmdir,
+	.mknod = ecryptfs_mknod,
+	.rename = ecryptfs_rename,
+	.permission = ecryptfs_permission,
+	.setattr = ecryptfs_setattr,
+	.setxattr = ecryptfs_setxattr,
+	.getxattr = ecryptfs_getxattr,
+	.listxattr = ecryptfs_listxattr,
+	.removexattr = ecryptfs_removexattr
+};
+
+const struct inode_operations ecryptfs_main_iops = {
+	.permission = ecryptfs_permission,
+	.setattr = ecryptfs_setattr,
+	.getattr = ecryptfs_getattr,
+	.setxattr = ecryptfs_setxattr,
+	.getxattr = ecryptfs_getxattr,
+	.listxattr = ecryptfs_listxattr,
+	.removexattr = ecryptfs_removexattr
+};