--- /dev/null
+/**
+ * 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/fs.h>
+#include <linux/mount.h>
+#include <linux/key.h>
+#include <linux/slab.h>
+#include <linux/seq_file.h>
+#include <linux/file.h>
+#include <linux/crypto.h>
+#include <linux/statfs.h>
+#include <linux/magic.h>
+#include "ecryptfs_kernel.h"
+
+struct kmem_cache *ecryptfs_inode_info_cache;
+
+/**
+ * ecryptfs_alloc_inode - allocate an ecryptfs inode
+ * @sb: Pointer to the ecryptfs super block
+ *
+ * Called to bring an inode into existence.
+ *
+ * Only handle allocation, setting up structures should be done in
+ * ecryptfs_read_inode. This is because the kernel, between now and
+ * then, will 0 out the private data pointer.
+ *
+ * Returns a pointer to a newly allocated inode, NULL otherwise
+ */
+static struct inode *ecryptfs_alloc_inode(struct super_block *sb)
+{
+ struct ecryptfs_inode_info *inode_info;
+ struct inode *inode = NULL;
+
+ inode_info = kmem_cache_alloc(ecryptfs_inode_info_cache, GFP_KERNEL);
+ if (unlikely(!inode_info))
+ goto out;
+ ecryptfs_init_crypt_stat(&inode_info->crypt_stat);
+ mutex_init(&inode_info->lower_file_mutex);
+ atomic_set(&inode_info->lower_file_count, 0);
+ inode_info->lower_file = NULL;
+ inode = &inode_info->vfs_inode;
+out:
+ return inode;
+}
+
+static void ecryptfs_i_callback(struct rcu_head *head)
+{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ struct ecryptfs_inode_info *inode_info;
+ inode_info = ecryptfs_inode_to_private(inode);
+
+ kmem_cache_free(ecryptfs_inode_info_cache, inode_info);
+}
+
+/**
+ * ecryptfs_destroy_inode
+ * @inode: The ecryptfs inode
+ *
+ * This is used during the final destruction of the inode. All
+ * allocation of memory related to the inode, including allocated
+ * memory in the crypt_stat struct, will be released here.
+ * There should be no chance that this deallocation will be missed.
+ */
+static void ecryptfs_destroy_inode(struct inode *inode)
+{
+ struct ecryptfs_inode_info *inode_info;
+
+ inode_info = ecryptfs_inode_to_private(inode);
+ BUG_ON(inode_info->lower_file);
+ ecryptfs_destroy_crypt_stat(&inode_info->crypt_stat);
+ call_rcu(&inode->i_rcu, ecryptfs_i_callback);
+}
+
+/**
+ * ecryptfs_statfs
+ * @sb: The ecryptfs super block
+ * @buf: The struct kstatfs to fill in with stats
+ *
+ * Get the filesystem statistics. Currently, we let this pass right through
+ * to the lower filesystem and take no action ourselves.
+ */
+static int ecryptfs_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+ struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
+ int rc;
+
+ if (!lower_dentry->d_sb->s_op->statfs)
+ return -ENOSYS;
+
+ rc = lower_dentry->d_sb->s_op->statfs(lower_dentry, buf);
+ if (rc)
+ return rc;
+
+ buf->f_type = ECRYPTFS_SUPER_MAGIC;
+ rc = ecryptfs_set_f_namelen(&buf->f_namelen, buf->f_namelen,
+ &ecryptfs_superblock_to_private(dentry->d_sb)->mount_crypt_stat);
+
+ return rc;
+}
+
+/**
+ * ecryptfs_evict_inode
+ * @inode - The ecryptfs inode
+ *
+ * Called by iput() when the inode reference count reached zero
+ * and the inode is not hashed anywhere. Used to clear anything
+ * that needs to be, before the inode is completely destroyed and put
+ * on the inode free list. We use this to drop out reference to the
+ * lower inode.
+ */
+static void ecryptfs_evict_inode(struct inode *inode)
+{
+ truncate_inode_pages_final(&inode->i_data);
+ clear_inode(inode);
+ iput(ecryptfs_inode_to_lower(inode));
+}
+
+/**
+ * ecryptfs_show_options
+ *
+ * Prints the mount options for a given superblock.
+ * Returns zero; does not fail.
+ */
+static int ecryptfs_show_options(struct seq_file *m, struct dentry *root)
+{
+ struct super_block *sb = root->d_sb;
+ struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
+ &ecryptfs_superblock_to_private(sb)->mount_crypt_stat;
+ struct ecryptfs_global_auth_tok *walker;
+
+ mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex);
+ list_for_each_entry(walker,
+ &mount_crypt_stat->global_auth_tok_list,
+ mount_crypt_stat_list) {
+ if (walker->flags & ECRYPTFS_AUTH_TOK_FNEK)
+ seq_printf(m, ",ecryptfs_fnek_sig=%s", walker->sig);
+ else
+ seq_printf(m, ",ecryptfs_sig=%s", walker->sig);
+ }
+ mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex);
+
+ seq_printf(m, ",ecryptfs_cipher=%s",
+ mount_crypt_stat->global_default_cipher_name);
+
+ if (mount_crypt_stat->global_default_cipher_key_size)
+ seq_printf(m, ",ecryptfs_key_bytes=%zd",
+ mount_crypt_stat->global_default_cipher_key_size);
+ if (mount_crypt_stat->flags & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)
+ seq_printf(m, ",ecryptfs_passthrough");
+ if (mount_crypt_stat->flags & ECRYPTFS_XATTR_METADATA_ENABLED)
+ seq_printf(m, ",ecryptfs_xattr_metadata");
+ if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED)
+ seq_printf(m, ",ecryptfs_encrypted_view");
+ if (mount_crypt_stat->flags & ECRYPTFS_UNLINK_SIGS)
+ seq_printf(m, ",ecryptfs_unlink_sigs");
+ if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY)
+ seq_printf(m, ",ecryptfs_mount_auth_tok_only");
+
+ return 0;
+}
+
+const struct super_operations ecryptfs_sops = {
+ .alloc_inode = ecryptfs_alloc_inode,
+ .destroy_inode = ecryptfs_destroy_inode,
+ .statfs = ecryptfs_statfs,
+ .remount_fs = NULL,
+ .evict_inode = ecryptfs_evict_inode,
+ .show_options = ecryptfs_show_options
+};
Code Review / kvmfornfv.git / blobdiff