static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry,
const char *symname)
{
int rc;
struct dentry *lower_dentry;
struct vfsmount *lower_mnt;
struct dentry *lower_dir_dentry;
umode_t mode;
char *encoded_symname;
int encoded_symlen;
struct ecryptfs_crypt_stat *crypt_stat = NULL;
lower_dentry = ecryptfs_dentry_to_lower(dentry);
dget(lower_dentry);
lower_mnt = ecryptfs_dentry_to_lower_mnt(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, lower_mnt,
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;
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;
}
/**
* 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 vfsmount *lower_mnt;
char *encoded_name;
int encoded_namelen;
struct ecryptfs_crypt_stat *crypt_stat = NULL;
struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
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, ".."))) {
d_drop(dentry);
goto out;
}
encoded_namelen = ecryptfs_encode_filename(crypt_stat,
dentry->d_name.name,
dentry->d_name.len,
&encoded_name);
if (encoded_namelen < 0) {
rc = encoded_namelen;
d_drop(dentry);
goto out;
}
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);
d_drop(dentry);
goto out;
}
lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(dentry->d_parent));
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;
fsstack_copy_attr_atime(dir, lower_dir_dentry->d_inode);
BUG_ON(!atomic_read(&lower_dentry->d_count));
ecryptfs_set_dentry_private(dentry,
kmem_cache_alloc(ecryptfs_dentry_info_cache,
GFP_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);
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);
goto out;
}
rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb,
ECRYPTFS_INTERPOSE_FLAG_D_ADD);
if (rc) {
ecryptfs_printk(KERN_ERR, "Error interposing\n");
goto out;
}
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 (special_file(lower_inode->i_mode)) {
ecryptfs_printk(KERN_DEBUG, "Is a special file; 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;
}
/* Released in this function */
page_virt = kmem_cache_zalloc(ecryptfs_header_cache_2,
GFP_USER);
if (!page_virt) {
rc = -ENOMEM;
ecryptfs_printk(KERN_ERR,
"Cannot ecryptfs_kmalloc a page\n");
goto out;
}
crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED))
ecryptfs_set_default_sizes(crypt_stat);
if (!ecryptfs_inode_to_private(dentry->d_inode)->lower_file) {
rc = ecryptfs_init_persistent_file(dentry);
if (rc) {
printk(KERN_ERR "%s: Error attempting to initialize "
"the persistent file for the dentry with name "
"[%s]; rc = [%d]\n", __func__,
dentry->d_name.name, rc);
goto out;
}
}
rc = ecryptfs_read_and_validate_header_region(page_virt,
dentry->d_inode);
if (rc) {
rc = ecryptfs_read_and_validate_xattr_region(page_virt, dentry);
if (rc) {
printk(KERN_DEBUG "Valid metadata not found in header "
"region or xattr region; treating file as "
"unencrypted\n");
rc = 0;
kmem_cache_free(ecryptfs_header_cache_2, page_virt);
goto out;
}
crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
}
mount_crypt_stat = &ecryptfs_superblock_to_private(
dentry->d_sb)->mount_crypt_stat;
if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) {
if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
file_size = (crypt_stat->num_header_bytes_at_front
+ i_size_read(lower_dentry->d_inode));
else
file_size = i_size_read(lower_dentry->d_inode);
} else {
file_size = get_unaligned_be64(page_virt);
}
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);
d_drop(dentry);
out:
return ERR_PTR(rc);
}