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    Subject[PATCH 9/13: eCryptfs] Inode operations
    This is the 9th patch in a series of 13 constituting the kernel
    components of the eCryptfs cryptographic filesystem.

    eCryptfs inode operations. Includes functions to support inode
    interpolation between upper and lower inodes.

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

    ---

    inode.c | 1080 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
    1 files changed, 1080 insertions(+)

    Index: linux-2.6.17-rc3-mm1-ecryptfs/fs/ecryptfs/inode.c
    ===================================================================
    --- /dev/null 1970-01-01 00:00:00.000000000 +0000
    +++ linux-2.6.17-rc3-mm1-ecryptfs/fs/ecryptfs/inode.c 2006-05-12 20:00:28.000000000 -0600
    @@ -0,0 +1,1080 @@
    +/**
    + * eCryptfs: Linux filesystem encryption layer
    + *
    + * Copyright (C) 1997-2004 Erez Zadok
    + * Copyright (C) 2001-2004 Stony Brook University
    + * Copyright (C) 2004-2006 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 "ecryptfs_kernel.h"
    +
    +static inline struct dentry *lock_parent(struct dentry *dentry)
    +{
    + struct dentry *dir;
    +
    + dir = dget(dentry->d_parent);
    + mutex_lock(&(dir->d_inode->i_mutex));
    + return dir;
    +}
    +
    +static inline void unlock_parent(struct dentry *dentry)
    +{
    + mutex_unlock(&(dentry->d_parent->d_inode->i_mutex));
    + dput(dentry->d_parent);
    +}
    +
    +static inline void unlock_dir(struct dentry *dir)
    +{
    + mutex_unlock(&dir->d_inode->i_mutex);
    + dput(dir);
    +}
    +
    +void ecryptfs_copy_inode_size(struct inode *dst, const struct inode *src)
    +{
    + i_size_write(dst, i_size_read((struct inode *)src));
    + dst->i_blocks = src->i_blocks;
    +}
    +
    +void ecryptfs_copy_attr_atime(struct inode *dest, const struct inode *src)
    +{
    + ASSERT(dest != NULL);
    + ASSERT(src != NULL);
    + dest->i_atime = src->i_atime;
    +}
    +
    +void ecryptfs_copy_attr_times(struct inode *dest, const struct inode *src)
    +{
    + ASSERT(dest != NULL);
    + ASSERT(src != NULL);
    + dest->i_atime = src->i_atime;
    + dest->i_mtime = src->i_mtime;
    + dest->i_ctime = src->i_ctime;
    +}
    +
    +static void ecryptfs_copy_attr_timesizes(struct inode *dest,
    + const struct inode *src)
    +{
    + ASSERT(dest != NULL);
    + ASSERT(src != NULL);
    + dest->i_atime = src->i_atime;
    + dest->i_mtime = src->i_mtime;
    + dest->i_ctime = src->i_ctime;
    + ecryptfs_copy_inode_size(dest, src);
    +}
    +
    +void ecryptfs_copy_attr_all(struct inode *dest, const struct inode *src)
    +{
    + ASSERT(dest != NULL);
    + ASSERT(src != NULL);
    + dest->i_mode = src->i_mode;
    + dest->i_nlink = src->i_nlink;
    + dest->i_uid = src->i_uid;
    + dest->i_gid = src->i_gid;
    + dest->i_rdev = src->i_rdev;
    + dest->i_atime = src->i_atime;
    + dest->i_mtime = src->i_mtime;
    + dest->i_ctime = src->i_ctime;
    + dest->i_blksize = src->i_blksize;
    + dest->i_blkbits = src->i_blkbits;
    + dest->i_flags = src->i_flags;
    +}
    +
    +/**
    + * ecryptfs_create_underlying_file
    + * @lower_dir_inode: inode of the parent in the lower fs of the new file
    + * @lower_dentry: New file's dentry in the lower fs
    + * @ecryptfs_dentry: New file's dentry in ecryptfs
    + * @mode: The mode of the new file
    + * @nd: nameidata of ecryptfs' parent's dentry & vfsmnt
    + *
    + * Creates the file in the lower file system.
    + *
    + * Returns zero on success; non-zero on error condition
    + */
    +static int
    +ecryptfs_create_underlying_file(struct inode *lower_dir_inode,
    + struct dentry *lower_dentry,
    + struct dentry *ecryptfs_dentry, int mode,
    + struct nameidata *nd)
    +{
    + int rc;
    + struct dentry *saved_dentry = NULL;
    + struct vfsmount *saved_vfsmount = NULL;
    +
    + saved_dentry = nd->dentry;
    + saved_vfsmount = nd->mnt;
    + nd->dentry = lower_dentry;
    + nd->mnt = ecryptfs_superblock_to_private(
    + ecryptfs_dentry->d_sb)->lower_mnt;
    + rc = vfs_create(lower_dir_inode, lower_dentry, mode, nd);
    + nd->dentry = saved_dentry;
    + nd->mnt = saved_vfsmount;
    + return rc;
    +}
    +
    +/**
    + * 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 & vfsmnt
    + *
    + * 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 zero on success; non-zero on error condition
    + */
    +static int
    +ecryptfs_do_create(struct inode *directory_inode,
    + struct dentry *ecryptfs_dentry, int mode,
    + struct nameidata *nd)
    +{
    + int rc;
    + struct dentry *lower_dentry;
    + struct dentry *lower_dir_dentry;
    +
    + lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
    + if (IS_ERR(lower_dentry)) {
    + ecryptfs_printk(KERN_ERR, "ecryptfs dentry doesn't know"
    + "about its lower counterpart\n");
    + rc = PTR_ERR(lower_dentry);
    + goto out;
    + }
    + lower_dir_dentry = lock_parent(lower_dentry);
    + if (unlikely(IS_ERR(lower_dir_dentry))) {
    + ecryptfs_printk(KERN_ERR, "Error locking directory of "
    + "dentry\n");
    + rc = PTR_ERR(lower_dir_dentry);
    + goto out;
    + }
    + rc = ecryptfs_create_underlying_file(lower_dir_dentry->d_inode,
    + lower_dentry, ecryptfs_dentry,
    + mode, nd);
    + if (unlikely(rc)) {
    + ecryptfs_printk(KERN_ERR,
    + "Failure to create underlying file\n");
    + goto out_lock;
    + }
    + rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry,
    + directory_inode->i_sb, 0);
    + if (rc) {
    + ecryptfs_printk(KERN_ERR, "Failure in ecryptfs_interpose\n");
    + goto out_lock;
    + }
    + ecryptfs_copy_attr_timesizes(directory_inode,
    + lower_dir_dentry->d_inode);
    +out_lock:
    + unlock_dir(lower_dir_dentry);
    +out:
    + return rc;
    +}
    +
    +/**
    + * grow_file
    + * @ecryptfs_dentry: the ecryptfs dentry
    + * @lower_file: The lower file
    + * @inode: The ecryptfs inode
    + * @lower_inode: The lower inode
    + *
    + * This is the code which will grow the file to its correct size.
    + */
    +static int grow_file(struct dentry *ecryptfs_dentry, struct file *lower_file,
    + struct inode *inode, struct inode *lower_inode)
    +{
    + int rc = 0;
    + struct file fake_file;
    + struct ecryptfs_file_info tmp_file_info;
    +
    + memset(&fake_file, 0, sizeof(fake_file));
    + fake_file.f_dentry = ecryptfs_dentry;
    + memset(&tmp_file_info, 0, sizeof(tmp_file_info));
    + ecryptfs_set_file_private(&fake_file, &tmp_file_info);
    + ecryptfs_set_file_lower(&fake_file, lower_file);
    + rc = ecryptfs_fill_zeros(&fake_file, 1);
    + if (rc) {
    + ECRYPTFS_SET_FLAG(
    + ecryptfs_inode_to_private(inode)->crypt_stat.flags,
    + ECRYPTFS_SECURITY_WARNING);
    + ecryptfs_printk(KERN_WARNING, "Error attempting to fill zeros "
    + "in file; rc = [%d]\n", rc);
    + goto out;
    + }
    + i_size_write(inode, 0);
    + ecryptfs_write_inode_size_to_header(lower_file, lower_inode, inode);
    + ECRYPTFS_SET_FLAG(ecryptfs_inode_to_private(inode)->crypt_stat.flags,
    + ECRYPTFS_NEW_FILE);
    +out:
    + return rc;
    +}
    +
    +/**
    + * 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)
    +{
    + int rc = 0;
    + int lower_flags;
    + struct ecryptfs_crypt_stat *crypt_stat;
    + struct dentry *lower_dentry;
    + struct dentry *tlower_dentry = NULL;
    + struct file *lower_file;
    + struct inode *inode, *lower_inode;
    + struct vfsmount *lower_mnt;
    +
    + lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
    + if (IS_ERR(lower_dentry)) {
    + ecryptfs_printk(KERN_ERR, "ecryptfs dentry doesn't know"
    + "about its lower counterpart\n");
    + rc = PTR_ERR(lower_dentry);
    + goto out;
    + }
    + ecryptfs_printk(KERN_DEBUG, "lower_dentry->d_name.name = [%s]\n",
    + lower_dentry->d_name.name);
    + inode = ecryptfs_dentry->d_inode;
    + crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
    + tlower_dentry = dget(lower_dentry);
    + if (!tlower_dentry) {
    + rc = -ENOMEM;
    + ecryptfs_printk(KERN_ERR, "Error dget'ing lower_dentry\n");
    + goto out;
    + }
    + lower_flags = ((O_CREAT | O_WRONLY | O_TRUNC) & O_ACCMODE) | O_RDWR;
    +#if BITS_PER_LONG != 32
    + lower_flags |= O_LARGEFILE;
    +#endif
    + lower_mnt = ecryptfs_superblock_to_private(inode->i_sb)->lower_mnt;
    + mntget(lower_mnt);
    + /* Corresponding fput() at end of this function */
    + lower_file = dentry_open(tlower_dentry, lower_mnt, lower_flags);
    + if (IS_ERR(lower_file)) {
    + rc = PTR_ERR(lower_file);
    + ecryptfs_printk(KERN_ERR,
    + "Error opening dentry; rc = [%i]\n", rc);
    + goto out;
    + }
    + /* fput(lower_file) should handle the puts if we do this */
    + lower_file->f_dentry = tlower_dentry;
    + lower_file->f_vfsmnt = lower_mnt;
    + lower_inode = tlower_dentry->d_inode;
    + if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) {
    + ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
    + ECRYPTFS_CLEAR_FLAG(crypt_stat->flags, ECRYPTFS_ENCRYPTED);
    + goto out_fput;
    + }
    + ECRYPTFS_SET_FLAG(crypt_stat->flags, ECRYPTFS_NEW_FILE);
    + ecryptfs_printk(KERN_DEBUG, "Initializing crypto context\n");
    + rc = ecryptfs_new_file_context(ecryptfs_dentry);
    + if (rc) {
    + ecryptfs_printk(KERN_DEBUG, "Error creating new file "
    + "context\n");
    + goto out_fput;
    + }
    + rc = ecryptfs_write_headers(ecryptfs_dentry, lower_file);
    + if (rc) {
    + ecryptfs_printk(KERN_DEBUG, "Error writing headers\n");
    + goto out_fput;
    + }
    + rc = grow_file(ecryptfs_dentry, lower_file, inode, lower_inode);
    +out_fput:
    + fput(lower_file);
    +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,
    + int mode, struct nameidata *nd)
    +{
    + int rc;
    +
    + rc = ecryptfs_do_create(directory_inode, ecryptfs_dentry, mode, nd);
    + if (unlikely(rc)) {
    + ecryptfs_printk(KERN_WARNING, "Failed to create file in"
    + "lower filesystem\n");
    + 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);
    +out:
    + return rc;
    +}
    +
    +/**
    + * ecryptfs_lookup
    + * @dir: inode
    + * @dentry: The dentry
    + * @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 *dir, struct dentry *dentry,
    + struct nameidata *nd)
    +{
    + int rc = 0;
    + struct dentry *lower_dir_dentry;
    + struct dentry *lower_dentry;
    + struct dentry *tlower_dentry = NULL;
    + char *encoded_name;
    + unsigned int encoded_namelen;
    + struct ecryptfs_crypt_stat *crypt_stat = NULL;
    + char *page_virt = NULL;
    + struct inode *lower_inode;
    + u64 file_size;
    +
    + lower_dir_dentry = ecryptfs_dentry_to_lower(dentry->d_parent);
    + dentry->d_op = &ecryptfs_dops;
    + if ((dentry->d_name.len == 1 && !strcmp(dentry->d_name.name, "."))
    + || (dentry->d_name.len == 2 && !strcmp(dentry->d_name.name, "..")))
    + goto out_drop;
    + encoded_namelen = ecryptfs_encode_filename(crypt_stat,
    + dentry->d_name.name,
    + dentry->d_name.len,
    + &encoded_name);
    + if (encoded_namelen < 0) {
    + rc = encoded_namelen;
    + goto out_drop;
    + }
    + ecryptfs_printk(KERN_DEBUG, "encoded_name = [%s]; encoded_namelen "
    + "= [%d]\n", encoded_name, encoded_namelen);
    + lower_dentry = lookup_one_len(encoded_name, lower_dir_dentry,
    + encoded_namelen - 1);
    + kfree(encoded_name);
    + if (IS_ERR(lower_dentry)) {
    + ecryptfs_printk(KERN_ERR, "ERR from lower_dentry\n");
    + rc = PTR_ERR(lower_dentry);
    + goto out_drop;
    + }
    + ecryptfs_printk(KERN_DEBUG, "lower_dentry = [%p]; lower_dentry->"
    + "d_name.name = [%s]\n", lower_dentry,
    + lower_dentry->d_name.name);
    + lower_inode = lower_dentry->d_inode;
    + ecryptfs_copy_attr_atime(dir, lower_dir_dentry->d_inode);
    + ASSERT(atomic_read(&lower_dentry->d_count));
    + ecryptfs_set_dentry_private(dentry,
    + kmem_cache_alloc(ecryptfs_dentry_info_cache,
    + SLAB_KERNEL));
    + if (!ecryptfs_dentry_to_private(dentry)) {
    + rc = -ENOMEM;
    + ecryptfs_printk(KERN_ERR, "Out of memory whilst attempting "
    + "to allocate ecryptfs_dentry_info struct\n");
    + goto out_dput;
    + }
    + ecryptfs_set_dentry_lower(dentry, lower_dentry);
    + if (!lower_dentry->d_inode) {
    + /* We want to add because we couldn't find in lower */
    + d_add(dentry, NULL);
    + goto out;
    + }
    + rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 1);
    + if (rc) {
    + ecryptfs_printk(KERN_ERR, "Error interposing\n");
    + goto out_dput;
    + }
    + if (S_ISDIR(lower_inode->i_mode)) {
    + ecryptfs_printk(KERN_DEBUG, "Is a directory; returning\n");
    + goto out;
    + }
    + if (S_ISLNK(lower_inode->i_mode)) {
    + ecryptfs_printk(KERN_DEBUG, "Is a symlink; returning\n");
    + goto out;
    + }
    + if (!nd) {
    + ecryptfs_printk(KERN_DEBUG, "We have a NULL nd, just leave"
    + "as we *think* we are about to unlink\n");
    + goto out;
    + }
    + tlower_dentry = dget(lower_dentry);
    + if (!tlower_dentry || IS_ERR(tlower_dentry)) {
    + rc = -ENOMEM;
    + ecryptfs_printk(KERN_ERR, "Cannot dget lower_dentry\n");
    + goto out_dput;
    + }
    + /* Released in this function */
    + page_virt =
    + (char *)kmem_cache_alloc(ecryptfs_header_cache_2,
    + SLAB_USER);
    + if (!page_virt) {
    + rc = -ENOMEM;
    + ecryptfs_printk(KERN_ERR,
    + "Cannot ecryptfs_kmalloc a page\n");
    + goto out_dput;
    + }
    + memset(page_virt, 0, PAGE_CACHE_SIZE);
    + rc = ecryptfs_read_header_region(page_virt, tlower_dentry, nd);
    + crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
    + if (!ECRYPTFS_CHECK_FLAG(crypt_stat->flags, ECRYPTFS_POLICY_APPLIED))
    + ecryptfs_set_default_sizes(crypt_stat);
    + if (rc) {
    + rc = 0;
    + ecryptfs_printk(KERN_WARNING, "Error reading header region;"
    + " assuming unencrypted\n");
    + } else {
    + if (!contains_ecryptfs_marker(page_virt
    + + ECRYPTFS_FILE_SIZE_BYTES)) {
    + ecryptfs_printk(KERN_WARNING, "Underlying file "
    + "lacks recognizable eCryptfs marker\n");
    + }
    + memcpy(&file_size, page_virt, sizeof(file_size));
    + file_size = be64_to_cpu(file_size);
    + i_size_write(dentry->d_inode, (loff_t)file_size);
    + }
    + kmem_cache_free(ecryptfs_header_cache_2, page_virt);
    + goto out;
    +
    +out_dput:
    + dput(lower_dentry);
    + if (tlower_dentry)
    + dput(tlower_dentry);
    +out_drop:
    + d_drop(dentry);
    +out:
    + return ERR_PTR(rc);
    +}
    +
    +static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
    + struct dentry *new_dentry)
    +{
    + int rc;
    + struct dentry *lower_old_dentry;
    + struct dentry *lower_new_dentry;
    + struct dentry *lower_dir_dentry;
    +
    + 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, 0);
    + if (rc)
    + goto out_lock;
    + ecryptfs_copy_attr_timesizes(dir, lower_new_dentry->d_inode);
    + old_dentry->d_inode->i_nlink =
    + ecryptfs_inode_to_lower(old_dentry->d_inode)->i_nlink;
    +out_lock:
    + unlock_dir(lower_dir_dentry);
    + dput(lower_new_dentry);
    + dput(lower_old_dentry);
    + if (!new_dentry->d_inode)
    + d_drop(new_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);
    +
    + lock_parent(lower_dentry);
    + rc = vfs_unlink(lower_dir_inode, lower_dentry);
    + if (rc) {
    + ecryptfs_printk(KERN_ERR, "Error in vfs_unlink\n");
    + goto out_unlock;
    + }
    + ecryptfs_copy_attr_times(dir, lower_dir_inode);
    + dentry->d_inode->i_nlink =
    + ecryptfs_inode_to_lower(dentry->d_inode)->i_nlink;
    + dentry->d_inode->i_ctime = dir->i_ctime;
    +out_unlock:
    + unlock_parent(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;
    + umode_t mode;
    + char *encoded_symname;
    + unsigned int encoded_symlen;
    + struct ecryptfs_crypt_stat *crypt_stat = NULL;
    +
    + lower_dentry = ecryptfs_dentry_to_lower(dentry);
    + dget(lower_dentry);
    + lower_dir_dentry = lock_parent(lower_dentry);
    + mode = S_IALLUGO;
    + encoded_symlen = ecryptfs_encode_filename(crypt_stat, symname,
    + strlen(symname),
    + &encoded_symname);
    + if (encoded_symlen < 0) {
    + rc = encoded_symlen;
    + goto out_lock;
    + }
    + rc = vfs_symlink(lower_dir_dentry->d_inode, lower_dentry,
    + encoded_symname, mode);
    + kfree(encoded_symname);
    + if (rc || !lower_dentry->d_inode)
    + goto out_lock;
    + rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
    + if (rc)
    + goto out_lock;
    + ecryptfs_copy_attr_timesizes(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, int 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, 0);
    + if (rc)
    + goto out;
    + ecryptfs_copy_attr_timesizes(dir, lower_dir_dentry->d_inode);
    + dir->i_nlink = 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)
    +{
    + int rc = 0;
    + struct dentry *tdentry = NULL;
    + struct dentry *lower_dentry;
    + struct dentry *tlower_dentry = NULL;
    + struct dentry *lower_dir_dentry;
    +
    + lower_dentry = ecryptfs_dentry_to_lower(dentry);
    + if (!(tdentry = dget(dentry))) {
    + rc = -EINVAL;
    + ecryptfs_printk(KERN_ERR, "Error dget'ing dentry [%p]\n",
    + dentry);
    + goto out;
    + }
    + lower_dir_dentry = lock_parent(lower_dentry);
    + if (!(tlower_dentry = dget(lower_dentry))) {
    + rc = -EINVAL;
    + ecryptfs_printk(KERN_ERR, "Error dget'ing lower_dentry "
    + "[%p]\n", lower_dentry);
    + goto out;
    + }
    + rc = vfs_rmdir(lower_dir_dentry->d_inode, lower_dentry);
    + if (!rc) {
    + d_delete(tlower_dentry);
    + tlower_dentry = NULL;
    + }
    + ecryptfs_copy_attr_times(dir, lower_dir_dentry->d_inode);
    + dir->i_nlink = lower_dir_dentry->d_inode->i_nlink;
    + unlock_dir(lower_dir_dentry);
    + if (!rc)
    + d_drop(dentry);
    +out:
    + if (tdentry)
    + dput(tdentry);
    + if (tlower_dentry)
    + dput(tlower_dentry);
    + return rc;
    +}
    +
    +static int
    +ecryptfs_mknod(struct inode *dir, struct dentry *dentry, int 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, 0);
    + if (rc)
    + goto out;
    + ecryptfs_copy_attr_timesizes(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;
    +
    + 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);
    + lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
    + 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;
    + ecryptfs_copy_attr_all(new_dir, lower_new_dir_dentry->d_inode);
    + if (new_dir != old_dir)
    + ecryptfs_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_dentry);
    + dput(lower_old_dentry);
    + return rc;
    +}
    +
    +static int
    +ecryptfs_readlink(struct dentry *dentry, char __user * buf, int bufsiz)
    +{
    + int rc;
    + struct dentry *lower_dentry;
    + char *decoded_name;
    + char *lower_buf;
    + mm_segment_t old_fs;
    + struct ecryptfs_crypt_stat *crypt_stat;
    +
    + lower_dentry = ecryptfs_dentry_to_lower(dentry);
    + if (!lower_dentry->d_inode->i_op ||
    + !lower_dentry->d_inode->i_op->readlink) {
    + rc = -EINVAL;
    + goto out;
    + }
    + /* Released in this function */
    + lower_buf = kmalloc(bufsiz, GFP_KERNEL);
    + if (lower_buf == NULL) {
    + ecryptfs_printk(KERN_ERR, "Out of memory\n");
    + rc = -ENOMEM;
    + goto out;
    + }
    + old_fs = get_fs();
    + set_fs(get_ds());
    + ecryptfs_printk(KERN_DEBUG, "Calling readlink w/ "
    + "lower_dentry->d_name.name = [%s]\n",
    + lower_dentry->d_name.name);
    + rc = lower_dentry->d_inode->i_op->readlink(lower_dentry,
    + (char __user *)lower_buf,
    + bufsiz);
    + set_fs(old_fs);
    + if (rc >= 0) {
    + crypt_stat = NULL;
    + rc = ecryptfs_decode_filename(crypt_stat, lower_buf, rc,
    + &decoded_name);
    + if (rc == -ENOMEM)
    + goto out_free_lower_buf;
    + if (rc > 0) {
    + ecryptfs_printk(KERN_DEBUG, "Copying [%d] bytes "
    + "to userspace: [%*s]\n", rc,
    + decoded_name);
    + if (copy_to_user(buf, decoded_name, rc))
    + rc = -EFAULT;
    + }
    + kfree(decoded_name);
    + ecryptfs_copy_attr_atime(dentry->d_inode,
    + lower_dentry->d_inode);
    + }
    +out_free_lower_buf:
    + kfree(lower_buf);
    +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) {
    + rc = -ENOMEM;
    + goto out;
    + }
    + old_fs = get_fs();
    + set_fs(get_ds());
    + ecryptfs_printk(KERN_DEBUG, "Calling readlink w/ "
    + "dentry->d_name.name = [%s]\n", dentry->d_name.name);
    + rc = dentry->d_inode->i_op->readlink(dentry, (char __user *)buf, len);
    + buf[rc] = '\0';
    + set_fs(old_fs);
    + if (rc < 0)
    + goto out_free;
    + rc = 0;
    + nd_set_link(nd, buf);
    + goto out;
    +out_free:
    + kfree(buf);
    +out:
    + return ERR_PTR(rc);
    +}
    +
    +static inline void
    +ecryptfs_put_link(struct dentry *dentry, struct nameidata *nd, void *ptr)
    +{
    + /* Free the char* */
    + kfree(nd_get_link(nd));
    +}
    +
    +/**
    + * upper_size_to_lower_size
    + * @crypt_stat: Crypt_stat associated with file
    + * @upper_size: Size of the upper file
    + *
    + * Calculate the requried 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 = ( crypt_stat->header_extent_size
    + * crypt_stat->num_header_extents_at_front );
    + 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;
    +}
    +
    +/**
    + * ecryptfs_truncate
    + * @dentry: The ecryptfs layer dentry
    + * @new_length: The length to expand the file to
    + *
    + * 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 need to modify the
    + * underlying file size according to the page index interpolations.
    + *
    + * Returns zero on success; non-zero otherwise
    + */
    +int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
    +{
    + int rc = 0;
    + struct inode *inode = dentry->d_inode;
    + struct dentry *lower_dentry;
    + struct file fake_ecryptfs_file, *lower_file = NULL;
    + 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((new_length == i_size)))
    + goto out;
    + crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
    + if (unlikely(!crypt_stat)) {
    + ecryptfs_printk(KERN_ERR, "NULL crypt_stat on dentry with "
    + "d_name.name = [%s]\n", dentry->d_name.name);
    + rc = -EINVAL;
    + goto out;
    + }
    + /* Set up a fake ecryptfs file, this is used to interface with
    + * the file in the underlying filesystem so that the
    + * truncation has an effect there as well. */
    + memset(&fake_ecryptfs_file, 0, sizeof(fake_ecryptfs_file));
    + fake_ecryptfs_file.f_dentry = dentry;
    + /* Released at out_free: label */
    + ecryptfs_set_file_private(&fake_ecryptfs_file,
    + kmem_cache_alloc(ecryptfs_file_info_cache,
    + SLAB_KERNEL));
    + if (unlikely(!ecryptfs_file_to_private(&fake_ecryptfs_file))) {
    + rc = -ENOMEM;
    + goto out;
    + }
    + lower_dentry = ecryptfs_dentry_to_lower(dentry);
    + /* This dget & mntget is released through fput at out_fput: */
    + dget(lower_dentry);
    + mntget(ecryptfs_superblock_to_private(inode->i_sb)->lower_mnt);
    + lower_file = dentry_open(
    + lower_dentry,
    + ecryptfs_superblock_to_private(inode->i_sb)->lower_mnt, O_RDWR);
    + if (unlikely(IS_ERR(lower_file))) {
    + rc = PTR_ERR(lower_file);
    + goto out_free;
    + }
    + ecryptfs_set_file_lower(&fake_ecryptfs_file, lower_file);
    + /* Switch on growing or shrinking file */
    + if (new_length > i_size) {
    + rc = ecryptfs_fill_zeros(&fake_ecryptfs_file, new_length);
    + if (rc) {
    + ecryptfs_printk(KERN_ERR,
    + "Problem with fill_zeros\n");
    + goto out_fput;
    + }
    + i_size_write(inode, new_length);
    + rc = ecryptfs_write_inode_size_to_header(lower_file,
    + lower_dentry->d_inode,
    + inode);
    + if (rc) {
    + ecryptfs_printk(KERN_ERR,
    + "Problem with ecryptfs_write"
    + "_inode_size\n");
    + goto out_fput;
    + }
    + } else { /* new_length < i_size_read(inode) */
    + vmtruncate(inode, new_length);
    + ecryptfs_write_inode_size_to_header(lower_file,
    + lower_dentry->d_inode,
    + inode);
    + /* 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, new_length);
    + if (lower_size_after_truncate < lower_size_before_truncate)
    + vmtruncate(lower_dentry->d_inode,
    + lower_size_after_truncate);
    + }
    + /* Update the access times */
    + lower_dentry->d_inode->i_mtime = lower_dentry->d_inode->i_ctime
    + = CURRENT_TIME;
    + mark_inode_dirty_sync(inode);
    +out_fput:
    + fput(lower_file);
    +out_free:
    + if (ecryptfs_file_to_private(&fake_ecryptfs_file))
    + kmem_cache_free(ecryptfs_file_info_cache,
    + ecryptfs_file_to_private(&fake_ecryptfs_file));
    +out:
    + return rc;
    +}
    +
    +static int
    +ecryptfs_permission(struct inode *inode, int mask, struct nameidata *nd)
    +{
    + struct inode *lower_inode;
    + int rc = 0;
    +
    + lower_inode = ecryptfs_inode_to_lower(inode);
    + if (nd)
    + ecryptfs_printk(KERN_DEBUG, "nd->dentry = [%p]\n",
    + nd->dentry);
    + rc = permission(lower_inode, mask, nd);
    + return rc;
    +}
    +
    +/**
    + * 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 inode *inode;
    + struct inode *lower_inode;
    + struct ecryptfs_crypt_stat *crypt_stat;
    +
    + crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
    + lower_dentry = ecryptfs_dentry_to_lower(dentry);
    + inode = dentry->d_inode;
    + lower_inode = ecryptfs_inode_to_lower(inode);
    + if (ia->ia_valid & ATTR_SIZE) {
    + ecryptfs_printk(KERN_DEBUG,
    + "ia->ia_valid = [0x%x] ATTR_SIZE" " = [0x%x]\n",
    + ia->ia_valid, ATTR_SIZE);
    + rc = ecryptfs_truncate(dentry, ia->ia_size);
    + /* ecryptfs_truncate handles resizing of the lower file */
    + ia->ia_valid &= ~ATTR_SIZE;
    + ecryptfs_printk(KERN_DEBUG, "ia->ia_valid = [%x]\n",
    + ia->ia_valid);
    + if (rc < 0)
    + goto out;
    + }
    + rc = notify_change(lower_dentry, ia);
    +out:
    + ecryptfs_copy_attr_all(inode, lower_inode);
    + return rc;
    +}
    +
    +static 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 = -ENOSYS;
    + goto out;
    + }
    + mutex_lock(&lower_dentry->d_inode->i_mutex);
    + rc = lower_dentry->d_inode->i_op->setxattr(lower_dentry, name, value,
    + size, flags);
    + 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)
    +{
    + int rc = 0;
    + struct dentry *lower_dentry;
    +
    + lower_dentry = ecryptfs_dentry_to_lower(dentry);
    + if (!lower_dentry->d_inode->i_op->getxattr) {
    + rc = -ENOSYS;
    + 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_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 = -ENOSYS;
    + 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 = -ENOSYS;
    + 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;
    +}
    +
    +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,
    + .setxattr = ecryptfs_setxattr,
    + .getxattr = ecryptfs_getxattr,
    + .listxattr = ecryptfs_listxattr,
    + .removexattr = ecryptfs_removexattr
    +};
    +
    +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
    +};
    +
    +struct inode_operations ecryptfs_main_iops = {
    + .permission = ecryptfs_permission,
    + .setattr = ecryptfs_setattr,
    + .setxattr = ecryptfs_setxattr,
    + .getxattr = ecryptfs_getxattr,
    + .listxattr = ecryptfs_listxattr,
    + .removexattr = ecryptfs_removexattr
    +};
    -
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      Last update: 2006-05-13 05:49    [W:2.941 / U:0.148 seconds]
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