include/linux/fscrypto.h - kernel/quantenna - Git at Google

 /*
  * General per-file encryption definition
  *
  * Copyright (C) 2015, Google, Inc.
  *
  * Written by Michael Halcrow, 2015.
  * Modified by Jaegeuk Kim, 2015.
  */

 #ifndef _LINUX_FSCRYPTO_H
 #define _LINUX_FSCRYPTO_H

 #include <linux/key.h>
 #include <linux/fs.h>
 #include <linux/mm.h>
 #include <linux/bio.h>
 #include <linux/dcache.h>
 #include <crypto/skcipher.h>
 #include <uapi/linux/fs.h>

 #define FS_KEY_DERIVATION_NONCE_SIZE		16
 #define FS_ENCRYPTION_CONTEXT_FORMAT_V1		1

 #define FS_POLICY_FLAGS_PAD_4		0x00
 #define FS_POLICY_FLAGS_PAD_8		0x01
 #define FS_POLICY_FLAGS_PAD_16		0x02
 #define FS_POLICY_FLAGS_PAD_32		0x03
 #define FS_POLICY_FLAGS_PAD_MASK	0x03
 #define FS_POLICY_FLAGS_VALID		0x03

 /* Encryption algorithms */
 #define FS_ENCRYPTION_MODE_INVALID		0
 #define FS_ENCRYPTION_MODE_AES_256_XTS		1
 #define FS_ENCRYPTION_MODE_AES_256_GCM		2
 #define FS_ENCRYPTION_MODE_AES_256_CBC		3
 #define FS_ENCRYPTION_MODE_AES_256_CTS		4

 /**
  * Encryption context for inode
  *
  * Protector format:
  *  1 byte: Protector format (1 = this version)
  *  1 byte: File contents encryption mode
  *  1 byte: File names encryption mode
  *  1 byte: Flags
  *  8 bytes: Master Key descriptor
  *  16 bytes: Encryption Key derivation nonce
  */
 struct fscrypt_context {
 	u8 format;
 	u8 contents_encryption_mode;
 	u8 filenames_encryption_mode;
 	u8 flags;
 	u8 master_key_descriptor[FS_KEY_DESCRIPTOR_SIZE];
 	u8 nonce[FS_KEY_DERIVATION_NONCE_SIZE];
 } __packed;

 /* Encryption parameters */
 #define FS_XTS_TWEAK_SIZE		16
 #define FS_AES_128_ECB_KEY_SIZE		16
 #define FS_AES_256_GCM_KEY_SIZE		32
 #define FS_AES_256_CBC_KEY_SIZE		32
 #define FS_AES_256_CTS_KEY_SIZE		32
 #define FS_AES_256_XTS_KEY_SIZE		64
 #define FS_MAX_KEY_SIZE			64

 #define FS_KEY_DESC_PREFIX		"fscrypt:"
 #define FS_KEY_DESC_PREFIX_SIZE		8

 /* This is passed in from userspace into the kernel keyring */
 struct fscrypt_key {
 	u32 mode;
 	u8 raw[FS_MAX_KEY_SIZE];
 	u32 size;
 } __packed;

 struct fscrypt_info {
 	u8 ci_data_mode;
 	u8 ci_filename_mode;
 	u8 ci_flags;
 	struct crypto_skcipher *ci_ctfm;
 	struct key *ci_keyring_key;
 	u8 ci_master_key[FS_KEY_DESCRIPTOR_SIZE];
 };

 #define FS_CTX_REQUIRES_FREE_ENCRYPT_FL		0x00000001
 #define FS_WRITE_PATH_FL			0x00000002

 struct fscrypt_ctx {
 	union {
 		struct {
 			struct page *bounce_page;	/* Ciphertext page */
 			struct page *control_page;	/* Original page  */
 		} w;
 		struct {
 			struct bio *bio;
 			struct work_struct work;
 		} r;
 		struct list_head free_list;	/* Free list */
 	};
 	u8 flags;				/* Flags */
 	u8 mode;				/* Encryption mode for tfm */
 };

 struct fscrypt_completion_result {
 	struct completion completion;
 	int res;
 };

 #define DECLARE_FS_COMPLETION_RESULT(ecr) \
 	struct fscrypt_completion_result ecr = { \
 		COMPLETION_INITIALIZER((ecr).completion), 0 }

 static inline int fscrypt_key_size(int mode)
 {
 	switch (mode) {
 	case FS_ENCRYPTION_MODE_AES_256_XTS:
 		return FS_AES_256_XTS_KEY_SIZE;
 	case FS_ENCRYPTION_MODE_AES_256_GCM:
 		return FS_AES_256_GCM_KEY_SIZE;
 	case FS_ENCRYPTION_MODE_AES_256_CBC:
 		return FS_AES_256_CBC_KEY_SIZE;
 	case FS_ENCRYPTION_MODE_AES_256_CTS:
 		return FS_AES_256_CTS_KEY_SIZE;
 	default:
 		BUG();
 	}
 	return 0;
 }

 #define FS_FNAME_NUM_SCATTER_ENTRIES	4
 #define FS_CRYPTO_BLOCK_SIZE		16
 #define FS_FNAME_CRYPTO_DIGEST_SIZE	32

 /**
  * For encrypted symlinks, the ciphertext length is stored at the beginning
  * of the string in little-endian format.
  */
 struct fscrypt_symlink_data {
 	__le16 len;
 	char encrypted_path[1];
 } __packed;

 /**
  * This function is used to calculate the disk space required to
  * store a filename of length l in encrypted symlink format.
  */
 static inline u32 fscrypt_symlink_data_len(u32 l)
 {
 	if (l < FS_CRYPTO_BLOCK_SIZE)
 		l = FS_CRYPTO_BLOCK_SIZE;
 	return (l + sizeof(struct fscrypt_symlink_data) - 1);
 }

 struct fscrypt_str {
 	unsigned char *name;
 	u32 len;
 };

 struct fscrypt_name {
 	const struct qstr *usr_fname;
 	struct fscrypt_str disk_name;
 	u32 hash;
 	u32 minor_hash;
 	struct fscrypt_str crypto_buf;
 };

 #define FSTR_INIT(n, l)		{ .name = n, .len = l }
 #define FSTR_TO_QSTR(f)		QSTR_INIT((f)->name, (f)->len)
 #define fname_name(p)		((p)->disk_name.name)
 #define fname_len(p)		((p)->disk_name.len)

 /*
  * crypto opertions for filesystems
  */
 struct fscrypt_operations {
 	int (*get_context)(struct inode *, void *, size_t);
 	int (*key_prefix)(struct inode *, u8 **);
 	int (*prepare_context)(struct inode *);
 	int (*set_context)(struct inode *, const void *, size_t, void *);
 	int (*dummy_context)(struct inode *);
 	bool (*is_encrypted)(struct inode *);
 	bool (*empty_dir)(struct inode *);
 	unsigned (*max_namelen)(struct inode *);
 };

 static inline bool fscrypt_dummy_context_enabled(struct inode *inode)
 {
 	if (inode->i_sb->s_cop->dummy_context &&
 				inode->i_sb->s_cop->dummy_context(inode))
 		return true;
 	return false;
 }

 static inline bool fscrypt_valid_contents_enc_mode(u32 mode)
 {
 	return (mode == FS_ENCRYPTION_MODE_AES_256_XTS);
 }

 static inline bool fscrypt_valid_filenames_enc_mode(u32 mode)
 {
 	return (mode == FS_ENCRYPTION_MODE_AES_256_CTS);
 }

 static inline u32 fscrypt_validate_encryption_key_size(u32 mode, u32 size)
 {
 	if (size == fscrypt_key_size(mode))
 		return size;
 	return 0;
 }

 static inline bool fscrypt_is_dot_dotdot(const struct qstr *str)
 {
 	if (str->len == 1 && str->name[0] == '.')
 		return true;

 	if (str->len == 2 && str->name[0] == '.' && str->name[1] == '.')
 		return true;

 	return false;
 }

 static inline struct page *fscrypt_control_page(struct page *page)
 {
 #if IS_ENABLED(CONFIG_FS_ENCRYPTION)
 	return ((struct fscrypt_ctx *)page_private(page))->w.control_page;
 #else
 	WARN_ON_ONCE(1);
 	return ERR_PTR(-EINVAL);
 #endif
 }

 static inline int fscrypt_has_encryption_key(struct inode *inode)
 {
 #if IS_ENABLED(CONFIG_FS_ENCRYPTION)
 	return (inode->i_crypt_info != NULL);
 #else
 	return 0;
 #endif
 }

 static inline void fscrypt_set_encrypted_dentry(struct dentry *dentry)
 {
 #if IS_ENABLED(CONFIG_FS_ENCRYPTION)
 	spin_lock(&dentry->d_lock);
 	dentry->d_flags |= DCACHE_ENCRYPTED_WITH_KEY;
 	spin_unlock(&dentry->d_lock);
 #endif
 }

 #if IS_ENABLED(CONFIG_FS_ENCRYPTION)
 extern const struct dentry_operations fscrypt_d_ops;
 #endif

 static inline void fscrypt_set_d_op(struct dentry *dentry)
 {
 #if IS_ENABLED(CONFIG_FS_ENCRYPTION)
 	d_set_d_op(dentry, &fscrypt_d_ops);
 #endif
 }

 #if IS_ENABLED(CONFIG_FS_ENCRYPTION)
 /* crypto.c */
 extern struct kmem_cache *fscrypt_info_cachep;
 int fscrypt_initialize(void);

 extern struct fscrypt_ctx *fscrypt_get_ctx(struct inode *, gfp_t);
 extern void fscrypt_release_ctx(struct fscrypt_ctx *);
 extern struct page *fscrypt_encrypt_page(struct inode *, struct page *, gfp_t);
 extern int fscrypt_decrypt_page(struct page *);
 extern void fscrypt_decrypt_bio_pages(struct fscrypt_ctx *, struct bio *);
 extern void fscrypt_pullback_bio_page(struct page **, bool);
 extern void fscrypt_restore_control_page(struct page *);
 extern int fscrypt_zeroout_range(struct inode *, pgoff_t, sector_t,
 						unsigned int);
 /* policy.c */
 extern int fscrypt_process_policy(struct inode *,
 					const struct fscrypt_policy *);
 extern int fscrypt_get_policy(struct inode *, struct fscrypt_policy *);
 extern int fscrypt_has_permitted_context(struct inode *, struct inode *);
 extern int fscrypt_inherit_context(struct inode *, struct inode *,
 					void *, bool);
 /* keyinfo.c */
 extern int get_crypt_info(struct inode *);
 extern int fscrypt_get_encryption_info(struct inode *);
 extern void fscrypt_put_encryption_info(struct inode *, struct fscrypt_info *);

 /* fname.c */
 extern int fscrypt_setup_filename(struct inode *, const struct qstr *,
 				int lookup, struct fscrypt_name *);
 extern void fscrypt_free_filename(struct fscrypt_name *);
 extern u32 fscrypt_fname_encrypted_size(struct inode *, u32);
 extern int fscrypt_fname_alloc_buffer(struct inode *, u32,
 				struct fscrypt_str *);
 extern void fscrypt_fname_free_buffer(struct fscrypt_str *);
 extern int fscrypt_fname_disk_to_usr(struct inode *, u32, u32,
 			const struct fscrypt_str *, struct fscrypt_str *);
 extern int fscrypt_fname_usr_to_disk(struct inode *, const struct qstr *,
 			struct fscrypt_str *);
 #endif

 /* crypto.c */
 static inline struct fscrypt_ctx *fscrypt_notsupp_get_ctx(struct inode *i,
 							gfp_t f)
 {
 	return ERR_PTR(-EOPNOTSUPP);
 }

 static inline void fscrypt_notsupp_release_ctx(struct fscrypt_ctx *c)
 {
 	return;
 }

 static inline struct page *fscrypt_notsupp_encrypt_page(struct inode *i,
 						struct page *p, gfp_t f)
 {
 	return ERR_PTR(-EOPNOTSUPP);
 }

 static inline int fscrypt_notsupp_decrypt_page(struct page *p)
 {
 	return -EOPNOTSUPP;
 }

 static inline void fscrypt_notsupp_decrypt_bio_pages(struct fscrypt_ctx *c,
 						struct bio *b)
 {
 	return;
 }

 static inline void fscrypt_notsupp_pullback_bio_page(struct page **p, bool b)
 {
 	return;
 }

 static inline void fscrypt_notsupp_restore_control_page(struct page *p)
 {
 	return;
 }

 static inline int fscrypt_notsupp_zeroout_range(struct inode *i, pgoff_t p,
 					sector_t s, unsigned int f)
 {
 	return -EOPNOTSUPP;
 }

 /* policy.c */
 static inline int fscrypt_notsupp_process_policy(struct inode *i,
 				const struct fscrypt_policy *p)
 {
 	return -EOPNOTSUPP;
 }

 static inline int fscrypt_notsupp_get_policy(struct inode *i,
 				struct fscrypt_policy *p)
 {
 	return -EOPNOTSUPP;
 }

 static inline int fscrypt_notsupp_has_permitted_context(struct inode *p,
 				struct inode *i)
 {
 	return 0;
 }

 static inline int fscrypt_notsupp_inherit_context(struct inode *p,
 				struct inode *i, void *v, bool b)
 {
 	return -EOPNOTSUPP;
 }

 /* keyinfo.c */
 static inline int fscrypt_notsupp_get_encryption_info(struct inode *i)
 {
 	return -EOPNOTSUPP;
 }

 static inline void fscrypt_notsupp_put_encryption_info(struct inode *i,
 					struct fscrypt_info *f)
 {
 	return;
 }

  /* fname.c */
 static inline int fscrypt_notsupp_setup_filename(struct inode *dir,
 			const struct qstr *iname,
 			int lookup, struct fscrypt_name *fname)
 {
 	if (dir->i_sb->s_cop->is_encrypted(dir))
 		return -EOPNOTSUPP;

 	memset(fname, 0, sizeof(struct fscrypt_name));
 	fname->usr_fname = iname;
 	fname->disk_name.name = (unsigned char *)iname->name;
 	fname->disk_name.len = iname->len;
 	return 0;
 }

 static inline void fscrypt_notsupp_free_filename(struct fscrypt_name *fname)
 {
 	return;
 }

 static inline u32 fscrypt_notsupp_fname_encrypted_size(struct inode *i, u32 s)
 {
 	/* never happens */
 	WARN_ON(1);
 	return 0;
 }

 static inline int fscrypt_notsupp_fname_alloc_buffer(struct inode *inode,
 				u32 ilen, struct fscrypt_str *crypto_str)
 {
 	return -EOPNOTSUPP;
 }

 static inline void fscrypt_notsupp_fname_free_buffer(struct fscrypt_str *c)
 {
 	return;
 }

 static inline int fscrypt_notsupp_fname_disk_to_usr(struct inode *inode,
 			u32 hash, u32 minor_hash,
 			const struct fscrypt_str *iname,
 			struct fscrypt_str *oname)
 {
 	return -EOPNOTSUPP;
 }

 static inline int fscrypt_notsupp_fname_usr_to_disk(struct inode *inode,
 			const struct qstr *iname,
 			struct fscrypt_str *oname)
 {
 	return -EOPNOTSUPP;
 }
 #endif	/* _LINUX_FSCRYPTO_H */
	/*
	* General per-file encryption definition
	*
	* Copyright (C) 2015, Google, Inc.
	*
	* Written by Michael Halcrow, 2015.
	* Modified by Jaegeuk Kim, 2015.
	*/

	#ifndef _LINUX_FSCRYPTO_H
	#define _LINUX_FSCRYPTO_H

	#include <linux/key.h>
	#include <linux/fs.h>
	#include <linux/mm.h>
	#include <linux/bio.h>
	#include <linux/dcache.h>
	#include <crypto/skcipher.h>
	#include <uapi/linux/fs.h>

	#define FS_KEY_DERIVATION_NONCE_SIZE 16
	#define FS_ENCRYPTION_CONTEXT_FORMAT_V1 1

	#define FS_POLICY_FLAGS_PAD_4 0x00
	#define FS_POLICY_FLAGS_PAD_8 0x01
	#define FS_POLICY_FLAGS_PAD_16 0x02
	#define FS_POLICY_FLAGS_PAD_32 0x03
	#define FS_POLICY_FLAGS_PAD_MASK 0x03
	#define FS_POLICY_FLAGS_VALID 0x03

	/* Encryption algorithms */
	#define FS_ENCRYPTION_MODE_INVALID 0
	#define FS_ENCRYPTION_MODE_AES_256_XTS 1
	#define FS_ENCRYPTION_MODE_AES_256_GCM 2
	#define FS_ENCRYPTION_MODE_AES_256_CBC 3
	#define FS_ENCRYPTION_MODE_AES_256_CTS 4

	/**
	* Encryption context for inode
	*
	* Protector format:
	* 1 byte: Protector format (1 = this version)
	* 1 byte: File contents encryption mode
	* 1 byte: File names encryption mode
	* 1 byte: Flags
	* 8 bytes: Master Key descriptor
	* 16 bytes: Encryption Key derivation nonce
	*/
	struct fscrypt_context {
	u8 format;
	u8 contents_encryption_mode;
	u8 filenames_encryption_mode;
	u8 flags;
	u8 master_key_descriptor[FS_KEY_DESCRIPTOR_SIZE];
	u8 nonce[FS_KEY_DERIVATION_NONCE_SIZE];
	} __packed;

	/* Encryption parameters */
	#define FS_XTS_TWEAK_SIZE 16
	#define FS_AES_128_ECB_KEY_SIZE 16
	#define FS_AES_256_GCM_KEY_SIZE 32
	#define FS_AES_256_CBC_KEY_SIZE 32
	#define FS_AES_256_CTS_KEY_SIZE 32
	#define FS_AES_256_XTS_KEY_SIZE 64
	#define FS_MAX_KEY_SIZE 64

	#define FS_KEY_DESC_PREFIX "fscrypt:"
	#define FS_KEY_DESC_PREFIX_SIZE 8

	/* This is passed in from userspace into the kernel keyring */
	struct fscrypt_key {
	u32 mode;
	u8 raw[FS_MAX_KEY_SIZE];
	u32 size;
	} __packed;

	struct fscrypt_info {
	u8 ci_data_mode;
	u8 ci_filename_mode;
	u8 ci_flags;
	struct crypto_skcipher *ci_ctfm;
	struct key *ci_keyring_key;
	u8 ci_master_key[FS_KEY_DESCRIPTOR_SIZE];
	};

	#define FS_CTX_REQUIRES_FREE_ENCRYPT_FL 0x00000001
	#define FS_WRITE_PATH_FL 0x00000002

	struct fscrypt_ctx {
	union {
	struct {
	struct page bounce_page; / Ciphertext page */
	struct page control_page; / Original page */
	} w;
	struct {
	struct bio *bio;
	struct work_struct work;
	} r;
	struct list_head free_list; /* Free list */
	};
	u8 flags; /* Flags */
	u8 mode; /* Encryption mode for tfm */
	};

	struct fscrypt_completion_result {
	struct completion completion;
	int res;
	};

	#define DECLARE_FS_COMPLETION_RESULT(ecr) \
	struct fscrypt_completion_result ecr = { \
	COMPLETION_INITIALIZER((ecr).completion), 0 }

	static inline int fscrypt_key_size(int mode)
	{
	switch (mode) {
	case FS_ENCRYPTION_MODE_AES_256_XTS:
	return FS_AES_256_XTS_KEY_SIZE;
	case FS_ENCRYPTION_MODE_AES_256_GCM:
	return FS_AES_256_GCM_KEY_SIZE;
	case FS_ENCRYPTION_MODE_AES_256_CBC:
	return FS_AES_256_CBC_KEY_SIZE;
	case FS_ENCRYPTION_MODE_AES_256_CTS:
	return FS_AES_256_CTS_KEY_SIZE;
	default:
	BUG();
	}
	return 0;
	}

	#define FS_FNAME_NUM_SCATTER_ENTRIES 4
	#define FS_CRYPTO_BLOCK_SIZE 16
	#define FS_FNAME_CRYPTO_DIGEST_SIZE 32

	/**
	* For encrypted symlinks, the ciphertext length is stored at the beginning
	* of the string in little-endian format.
	*/
	struct fscrypt_symlink_data {
	__le16 len;
	char encrypted_path[1];
	} __packed;

	/**
	* This function is used to calculate the disk space required to
	* store a filename of length l in encrypted symlink format.
	*/
	static inline u32 fscrypt_symlink_data_len(u32 l)
	{
	if (l < FS_CRYPTO_BLOCK_SIZE)
	l = FS_CRYPTO_BLOCK_SIZE;
	return (l + sizeof(struct fscrypt_symlink_data) - 1);
	}

	struct fscrypt_str {
	unsigned char *name;
	u32 len;
	};

	struct fscrypt_name {
	const struct qstr *usr_fname;
	struct fscrypt_str disk_name;
	u32 hash;
	u32 minor_hash;
	struct fscrypt_str crypto_buf;
	};

	#define FSTR_INIT(n, l) { .name = n, .len = l }
	#define FSTR_TO_QSTR(f) QSTR_INIT((f)->name, (f)->len)
	#define fname_name(p) ((p)->disk_name.name)
	#define fname_len(p) ((p)->disk_name.len)

	/*
	* crypto opertions for filesystems
	*/
	struct fscrypt_operations {
	int (get_context)(struct inode , void *, size_t);
	int (key_prefix)(struct inode , u8 **);
	int (prepare_context)(struct inode );
	int (set_context)(struct inode , const void , size_t, void );
	int (dummy_context)(struct inode );
	bool (is_encrypted)(struct inode );
	bool (empty_dir)(struct inode );
	unsigned (max_namelen)(struct inode );
	};

	static inline bool fscrypt_dummy_context_enabled(struct inode *inode)
	{
	if (inode->i_sb->s_cop->dummy_context &&
	inode->i_sb->s_cop->dummy_context(inode))
	return true;
	return false;
	}

	static inline bool fscrypt_valid_contents_enc_mode(u32 mode)
	{
	return (mode == FS_ENCRYPTION_MODE_AES_256_XTS);
	}

	static inline bool fscrypt_valid_filenames_enc_mode(u32 mode)
	{
	return (mode == FS_ENCRYPTION_MODE_AES_256_CTS);
	}

	static inline u32 fscrypt_validate_encryption_key_size(u32 mode, u32 size)
	{
	if (size == fscrypt_key_size(mode))
	return size;
	return 0;
	}

	static inline bool fscrypt_is_dot_dotdot(const struct qstr *str)
	{
	if (str->len == 1 && str->name[0] == '.')
	return true;

	if (str->len == 2 && str->name[0] == '.' && str->name[1] == '.')
	return true;

	return false;
	}

	static inline struct page fscrypt_control_page(struct page page)
	{
	#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
	return ((struct fscrypt_ctx *)page_private(page))->w.control_page;
	#else
	WARN_ON_ONCE(1);
	return ERR_PTR(-EINVAL);
	#endif
	}

	static inline int fscrypt_has_encryption_key(struct inode *inode)
	{
	#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
	return (inode->i_crypt_info != NULL);
	#else
	return 0;
	#endif
	}

	static inline void fscrypt_set_encrypted_dentry(struct dentry *dentry)
	{
	#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
	spin_lock(&dentry->d_lock);
	dentry->d_flags \|= DCACHE_ENCRYPTED_WITH_KEY;
	spin_unlock(&dentry->d_lock);
	#endif
	}

	#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
	extern const struct dentry_operations fscrypt_d_ops;
	#endif

	static inline void fscrypt_set_d_op(struct dentry *dentry)
	{
	#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
	d_set_d_op(dentry, &fscrypt_d_ops);
	#endif
	}

	#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
	/* crypto.c */
	extern struct kmem_cache *fscrypt_info_cachep;
	int fscrypt_initialize(void);

	extern struct fscrypt_ctx fscrypt_get_ctx(struct inode , gfp_t);
	extern void fscrypt_release_ctx(struct fscrypt_ctx *);
	extern struct page fscrypt_encrypt_page(struct inode , struct page *, gfp_t);
	extern int fscrypt_decrypt_page(struct page *);
	extern void fscrypt_decrypt_bio_pages(struct fscrypt_ctx , struct bio );
	extern void fscrypt_pullback_bio_page(struct page **, bool);
	extern void fscrypt_restore_control_page(struct page *);
	extern int fscrypt_zeroout_range(struct inode *, pgoff_t, sector_t,
	unsigned int);
	/* policy.c */
	extern int fscrypt_process_policy(struct inode *,
	const struct fscrypt_policy *);
	extern int fscrypt_get_policy(struct inode , struct fscrypt_policy );
	extern int fscrypt_has_permitted_context(struct inode , struct inode );
	extern int fscrypt_inherit_context(struct inode , struct inode ,
	void *, bool);
	/* keyinfo.c */
	extern int get_crypt_info(struct inode *);
	extern int fscrypt_get_encryption_info(struct inode *);
	extern void fscrypt_put_encryption_info(struct inode , struct fscrypt_info );

	/* fname.c */
	extern int fscrypt_setup_filename(struct inode , const struct qstr ,
	int lookup, struct fscrypt_name *);
	extern void fscrypt_free_filename(struct fscrypt_name *);
	extern u32 fscrypt_fname_encrypted_size(struct inode *, u32);
	extern int fscrypt_fname_alloc_buffer(struct inode *, u32,
	struct fscrypt_str *);
	extern void fscrypt_fname_free_buffer(struct fscrypt_str *);
	extern int fscrypt_fname_disk_to_usr(struct inode *, u32, u32,
	const struct fscrypt_str , struct fscrypt_str );
	extern int fscrypt_fname_usr_to_disk(struct inode , const struct qstr ,
	struct fscrypt_str *);
	#endif

	/* crypto.c */
	static inline struct fscrypt_ctx fscrypt_notsupp_get_ctx(struct inode i,
	gfp_t f)
	{
	return ERR_PTR(-EOPNOTSUPP);
	}

	static inline void fscrypt_notsupp_release_ctx(struct fscrypt_ctx *c)
	{
	return;
	}

	static inline struct page fscrypt_notsupp_encrypt_page(struct inode i,
	struct page *p, gfp_t f)
	{
	return ERR_PTR(-EOPNOTSUPP);
	}

	static inline int fscrypt_notsupp_decrypt_page(struct page *p)
	{
	return -EOPNOTSUPP;
	}

	static inline void fscrypt_notsupp_decrypt_bio_pages(struct fscrypt_ctx *c,
	struct bio *b)
	{
	return;
	}

	static inline void fscrypt_notsupp_pullback_bio_page(struct page **p, bool b)
	{
	return;
	}

	static inline void fscrypt_notsupp_restore_control_page(struct page *p)
	{
	return;
	}

	static inline int fscrypt_notsupp_zeroout_range(struct inode *i, pgoff_t p,
	sector_t s, unsigned int f)
	{
	return -EOPNOTSUPP;
	}

	/* policy.c */
	static inline int fscrypt_notsupp_process_policy(struct inode *i,
	const struct fscrypt_policy *p)
	{
	return -EOPNOTSUPP;
	}

	static inline int fscrypt_notsupp_get_policy(struct inode *i,
	struct fscrypt_policy *p)
	{
	return -EOPNOTSUPP;
	}

	static inline int fscrypt_notsupp_has_permitted_context(struct inode *p,
	struct inode *i)
	{
	return 0;
	}

	static inline int fscrypt_notsupp_inherit_context(struct inode *p,
	struct inode i, void v, bool b)
	{
	return -EOPNOTSUPP;
	}

	/* keyinfo.c */
	static inline int fscrypt_notsupp_get_encryption_info(struct inode *i)
	{
	return -EOPNOTSUPP;
	}

	static inline void fscrypt_notsupp_put_encryption_info(struct inode *i,
	struct fscrypt_info *f)
	{
	return;
	}

	/* fname.c */
	static inline int fscrypt_notsupp_setup_filename(struct inode *dir,
	const struct qstr *iname,
	int lookup, struct fscrypt_name *fname)
	{
	if (dir->i_sb->s_cop->is_encrypted(dir))
	return -EOPNOTSUPP;

	memset(fname, 0, sizeof(struct fscrypt_name));
	fname->usr_fname = iname;
	fname->disk_name.name = (unsigned char *)iname->name;
	fname->disk_name.len = iname->len;
	return 0;
	}

	static inline void fscrypt_notsupp_free_filename(struct fscrypt_name *fname)
	{
	return;
	}

	static inline u32 fscrypt_notsupp_fname_encrypted_size(struct inode *i, u32 s)
	{
	/* never happens */
	WARN_ON(1);
	return 0;
	}

	static inline int fscrypt_notsupp_fname_alloc_buffer(struct inode *inode,
	u32 ilen, struct fscrypt_str *crypto_str)
	{
	return -EOPNOTSUPP;
	}

	static inline void fscrypt_notsupp_fname_free_buffer(struct fscrypt_str *c)
	{
	return;
	}

	static inline int fscrypt_notsupp_fname_disk_to_usr(struct inode *inode,
	u32 hash, u32 minor_hash,
	const struct fscrypt_str *iname,
	struct fscrypt_str *oname)
	{
	return -EOPNOTSUPP;
	}

	static inline int fscrypt_notsupp_fname_usr_to_disk(struct inode *inode,
	const struct qstr *iname,
	struct fscrypt_str *oname)
	{
	return -EOPNOTSUPP;
	}
	#endif /* _LINUX_FSCRYPTO_H */