ext4 crypto: migrate into vfs's crypto engine

This patch removes the most parts of internal crypto codes.
And then, it modifies and adds some ext4-specific crypt codes to use the generic
facility.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

19 files changed, 297 insertions, 1997 deletions

diff --git a/fs/ext4/Kconfig b/fs/ext4/Kconfig
index b46e9fc..e38039f 100644
--- a/fs/ext4/Kconfig
+++ b/fs/ext4/Kconfig
@@ -99,17 +99,9 @@ config EXT4_FS_SECURITY
 	  extended attributes for file security labels, say N.
 
 config EXT4_ENCRYPTION
-	tristate "Ext4 Encryption"
+	bool "Ext4 Encryption"
 	depends on EXT4_FS
-	select CRYPTO_AES
-	select CRYPTO_CBC
-	select CRYPTO_ECB
-	select CRYPTO_XTS
-	select CRYPTO_CTS
-	select CRYPTO_CTR
-	select CRYPTO_SHA256
-	select KEYS
-	select ENCRYPTED_KEYS
+	select FS_ENCRYPTION
 	help
 	  Enable encryption of ext4 files and directories.  This
 	  feature is similar to ecryptfs, but it is more memory
diff --git a/fs/ext4/Makefile b/fs/ext4/Makefile
index f52cf54..354103f 100644
--- a/fs/ext4/Makefile
+++ b/fs/ext4/Makefile
@@ -12,5 +12,3 @@ ext4-y	:= balloc.o bitmap.o dir.o file.o fsync.o ialloc.o inode.o page-io.o \
 
 ext4-$(CONFIG_EXT4_FS_POSIX_ACL)	+= acl.o
 ext4-$(CONFIG_EXT4_FS_SECURITY)		+= xattr_security.o
-ext4-$(CONFIG_EXT4_FS_ENCRYPTION)	+= crypto_policy.o crypto.o \
-		crypto_key.o crypto_fname.o
diff --git a/fs/ext4/crypto.c b/fs/ext4/crypto.c
deleted file mode 100644
index 6a6c273..0000000
--- a/fs/ext4/crypto.c
+++ /dev/null
@@ -1,536 +0,0 @@
-/*
- * linux/fs/ext4/crypto.c
- *
- * Copyright (C) 2015, Google, Inc.
- *
- * This contains encryption functions for ext4
- *
- * Written by Michael Halcrow, 2014.
- *
- * Filename encryption additions
- *	Uday Savagaonkar, 2014
- * Encryption policy handling additions
- *	Ildar Muslukhov, 2014
- *
- * This has not yet undergone a rigorous security audit.
- *
- * The usage of AES-XTS should conform to recommendations in NIST
- * Special Publication 800-38E and IEEE P1619/D16.
- */
-
-#include <crypto/skcipher.h>
-#include <keys/user-type.h>
-#include <keys/encrypted-type.h>
-#include <linux/ecryptfs.h>
-#include <linux/gfp.h>
-#include <linux/kernel.h>
-#include <linux/key.h>
-#include <linux/list.h>
-#include <linux/mempool.h>
-#include <linux/module.h>
-#include <linux/mutex.h>
-#include <linux/random.h>
-#include <linux/scatterlist.h>
-#include <linux/spinlock_types.h>
-#include <linux/namei.h>
-
-#include "ext4_extents.h"
-#include "xattr.h"
-
-/* Encryption added and removed here! (L: */
-
-static unsigned int num_prealloc_crypto_pages = 32;
-static unsigned int num_prealloc_crypto_ctxs = 128;
-
-module_param(num_prealloc_crypto_pages, uint, 0444);
-MODULE_PARM_DESC(num_prealloc_crypto_pages,
-		 "Number of crypto pages to preallocate");
-module_param(num_prealloc_crypto_ctxs, uint, 0444);
-MODULE_PARM_DESC(num_prealloc_crypto_ctxs,
-		 "Number of crypto contexts to preallocate");
-
-static mempool_t *ext4_bounce_page_pool;
-
-static LIST_HEAD(ext4_free_crypto_ctxs);
-static DEFINE_SPINLOCK(ext4_crypto_ctx_lock);
-
-static struct kmem_cache *ext4_crypto_ctx_cachep;
-struct kmem_cache *ext4_crypt_info_cachep;
-
-/**
- * ext4_release_crypto_ctx() - Releases an encryption context
- * @ctx: The encryption context to release.
- *
- * If the encryption context was allocated from the pre-allocated pool, returns
- * it to that pool. Else, frees it.
- *
- * If there's a bounce page in the context, this frees that.
- */
-void ext4_release_crypto_ctx(struct ext4_crypto_ctx *ctx)
-{
-	unsigned long flags;
-
-	if (ctx->flags & EXT4_WRITE_PATH_FL && ctx->w.bounce_page)
-		mempool_free(ctx->w.bounce_page, ext4_bounce_page_pool);
-	ctx->w.bounce_page = NULL;
-	ctx->w.control_page = NULL;
-	if (ctx->flags & EXT4_CTX_REQUIRES_FREE_ENCRYPT_FL) {
-		kmem_cache_free(ext4_crypto_ctx_cachep, ctx);
-	} else {
-		spin_lock_irqsave(&ext4_crypto_ctx_lock, flags);
-		list_add(&ctx->free_list, &ext4_free_crypto_ctxs);
-		spin_unlock_irqrestore(&ext4_crypto_ctx_lock, flags);
-	}
-}
-
-/**
- * ext4_get_crypto_ctx() - Gets an encryption context
- * @inode:       The inode for which we are doing the crypto
- *
- * Allocates and initializes an encryption context.
- *
- * Return: An allocated and initialized encryption context on success; error
- * value or NULL otherwise.
- */
-struct ext4_crypto_ctx *ext4_get_crypto_ctx(struct inode *inode,
-					    gfp_t gfp_flags)
-{
-	struct ext4_crypto_ctx *ctx = NULL;
-	int res = 0;
-	unsigned long flags;
-	struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info;
-
-	if (ci == NULL)
-		return ERR_PTR(-ENOKEY);
-
-	/*
-	 * We first try getting the ctx from a free list because in
-	 * the common case the ctx will have an allocated and
-	 * initialized crypto tfm, so it's probably a worthwhile
-	 * optimization. For the bounce page, we first try getting it
-	 * from the kernel allocator because that's just about as fast
-	 * as getting it from a list and because a cache of free pages
-	 * should generally be a "last resort" option for a filesystem
-	 * to be able to do its job.
-	 */
-	spin_lock_irqsave(&ext4_crypto_ctx_lock, flags);
-	ctx = list_first_entry_or_null(&ext4_free_crypto_ctxs,
-				       struct ext4_crypto_ctx, free_list);
-	if (ctx)
-		list_del(&ctx->free_list);
-	spin_unlock_irqrestore(&ext4_crypto_ctx_lock, flags);
-	if (!ctx) {
-		ctx = kmem_cache_zalloc(ext4_crypto_ctx_cachep, gfp_flags);
-		if (!ctx) {
-			res = -ENOMEM;
-			goto out;
-		}
-		ctx->flags |= EXT4_CTX_REQUIRES_FREE_ENCRYPT_FL;
-	} else {
-		ctx->flags &= ~EXT4_CTX_REQUIRES_FREE_ENCRYPT_FL;
-	}
-	ctx->flags &= ~EXT4_WRITE_PATH_FL;
-
-out:
-	if (res) {
-		if (!IS_ERR_OR_NULL(ctx))
-			ext4_release_crypto_ctx(ctx);
-		ctx = ERR_PTR(res);
-	}
-	return ctx;
-}
-
-struct workqueue_struct *ext4_read_workqueue;
-static DEFINE_MUTEX(crypto_init);
-
-/**
- * ext4_exit_crypto() - Shutdown the ext4 encryption system
- */
-void ext4_exit_crypto(void)
-{
-	struct ext4_crypto_ctx *pos, *n;
-
-	list_for_each_entry_safe(pos, n, &ext4_free_crypto_ctxs, free_list)
-		kmem_cache_free(ext4_crypto_ctx_cachep, pos);
-	INIT_LIST_HEAD(&ext4_free_crypto_ctxs);
-	if (ext4_bounce_page_pool)
-		mempool_destroy(ext4_bounce_page_pool);
-	ext4_bounce_page_pool = NULL;
-	if (ext4_read_workqueue)
-		destroy_workqueue(ext4_read_workqueue);
-	ext4_read_workqueue = NULL;
-	if (ext4_crypto_ctx_cachep)
-		kmem_cache_destroy(ext4_crypto_ctx_cachep);
-	ext4_crypto_ctx_cachep = NULL;
-	if (ext4_crypt_info_cachep)
-		kmem_cache_destroy(ext4_crypt_info_cachep);
-	ext4_crypt_info_cachep = NULL;
-}
-
-/**
- * ext4_init_crypto() - Set up for ext4 encryption.
- *
- * We only call this when we start accessing encrypted files, since it
- * results in memory getting allocated that wouldn't otherwise be used.
- *
- * Return: Zero on success, non-zero otherwise.
- */
-int ext4_init_crypto(void)
-{
-	int i, res = -ENOMEM;
-
-	mutex_lock(&crypto_init);
-	if (ext4_read_workqueue)
-		goto already_initialized;
-	ext4_read_workqueue = alloc_workqueue("ext4_crypto", WQ_HIGHPRI, 0);
-	if (!ext4_read_workqueue)
-		goto fail;
-
-	ext4_crypto_ctx_cachep = KMEM_CACHE(ext4_crypto_ctx,
-					    SLAB_RECLAIM_ACCOUNT);
-	if (!ext4_crypto_ctx_cachep)
-		goto fail;
-
-	ext4_crypt_info_cachep = KMEM_CACHE(ext4_crypt_info,
-					    SLAB_RECLAIM_ACCOUNT);
-	if (!ext4_crypt_info_cachep)
-		goto fail;
-
-	for (i = 0; i < num_prealloc_crypto_ctxs; i++) {
-		struct ext4_crypto_ctx *ctx;
-
-		ctx = kmem_cache_zalloc(ext4_crypto_ctx_cachep, GFP_NOFS);
-		if (!ctx) {
-			res = -ENOMEM;
-			goto fail;
-		}
-		list_add(&ctx->free_list, &ext4_free_crypto_ctxs);
-	}
-
-	ext4_bounce_page_pool =
-		mempool_create_page_pool(num_prealloc_crypto_pages, 0);
-	if (!ext4_bounce_page_pool) {
-		res = -ENOMEM;
-		goto fail;
-	}
-already_initialized:
-	mutex_unlock(&crypto_init);
-	return 0;
-fail:
-	ext4_exit_crypto();
-	mutex_unlock(&crypto_init);
-	return res;
-}
-
-void ext4_restore_control_page(struct page *data_page)
-{
-	struct ext4_crypto_ctx *ctx =
-		(struct ext4_crypto_ctx *)page_private(data_page);
-
-	set_page_private(data_page, (unsigned long)NULL);
-	ClearPagePrivate(data_page);
-	unlock_page(data_page);
-	ext4_release_crypto_ctx(ctx);
-}
-
-/**
- * ext4_crypt_complete() - The completion callback for page encryption
- * @req: The asynchronous encryption request context
- * @res: The result of the encryption operation
- */
-static void ext4_crypt_complete(struct crypto_async_request *req, int res)
-{
-	struct ext4_completion_result *ecr = req->data;
-
-	if (res == -EINPROGRESS)
-		return;
-	ecr->res = res;
-	complete(&ecr->completion);
-}
-
-typedef enum {
-	EXT4_DECRYPT = 0,
-	EXT4_ENCRYPT,
-} ext4_direction_t;
-
-static int ext4_page_crypto(struct inode *inode,
-			    ext4_direction_t rw,
-			    pgoff_t index,
-			    struct page *src_page,
-			    struct page *dest_page,
-			    gfp_t gfp_flags)
-
-{
-	u8 xts_tweak[EXT4_XTS_TWEAK_SIZE];
-	struct skcipher_request *req = NULL;
-	DECLARE_EXT4_COMPLETION_RESULT(ecr);
-	struct scatterlist dst, src;
-	struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info;
-	struct crypto_skcipher *tfm = ci->ci_ctfm;
-	int res = 0;
-
-	req = skcipher_request_alloc(tfm, gfp_flags);
-	if (!req) {
-		printk_ratelimited(KERN_ERR
-				   "%s: crypto_request_alloc() failed\n",
-				   __func__);
-		return -ENOMEM;
-	}
-	skcipher_request_set_callback(
-		req, CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
-		ext4_crypt_complete, &ecr);
-
-	BUILD_BUG_ON(EXT4_XTS_TWEAK_SIZE < sizeof(index));
-	memcpy(xts_tweak, &index, sizeof(index));
-	memset(&xts_tweak[sizeof(index)], 0,
-	       EXT4_XTS_TWEAK_SIZE - sizeof(index));
-
-	sg_init_table(&dst, 1);
-	sg_set_page(&dst, dest_page, PAGE_SIZE, 0);
-	sg_init_table(&src, 1);
-	sg_set_page(&src, src_page, PAGE_SIZE, 0);
-	skcipher_request_set_crypt(req, &src, &dst, PAGE_SIZE,
-				   xts_tweak);
-	if (rw == EXT4_DECRYPT)
-		res = crypto_skcipher_decrypt(req);
-	else
-		res = crypto_skcipher_encrypt(req);
-	if (res == -EINPROGRESS || res == -EBUSY) {
-		wait_for_completion(&ecr.completion);
-		res = ecr.res;
-	}
-	skcipher_request_free(req);
-	if (res) {
-		printk_ratelimited(
-			KERN_ERR
-			"%s: crypto_skcipher_encrypt() returned %d\n",
-			__func__, res);
-		return res;
-	}
-	return 0;
-}
-
-static struct page *alloc_bounce_page(struct ext4_crypto_ctx *ctx,
-				      gfp_t gfp_flags)
-{
-	ctx->w.bounce_page = mempool_alloc(ext4_bounce_page_pool, gfp_flags);
-	if (ctx->w.bounce_page == NULL)
-		return ERR_PTR(-ENOMEM);
-	ctx->flags |= EXT4_WRITE_PATH_FL;
-	return ctx->w.bounce_page;
-}
-
-/**
- * ext4_encrypt() - Encrypts a page
- * @inode:          The inode for which the encryption should take place
- * @plaintext_page: The page to encrypt. Must be locked.
- *
- * Allocates a ciphertext page and encrypts plaintext_page into it using the ctx
- * encryption context.
- *
- * Called on the page write path.  The caller must call
- * ext4_restore_control_page() on the returned ciphertext page to
- * release the bounce buffer and the encryption context.
- *
- * Return: An allocated page with the encrypted content on success. Else, an
- * error value or NULL.
- */
-struct page *ext4_encrypt(struct inode *inode,
-			  struct page *plaintext_page,
-			  gfp_t gfp_flags)
-{
-	struct ext4_crypto_ctx *ctx;
-	struct page *ciphertext_page = NULL;
-	int err;
-
-	BUG_ON(!PageLocked(plaintext_page));
-
-	ctx = ext4_get_crypto_ctx(inode, gfp_flags);
-	if (IS_ERR(ctx))
-		return (struct page *) ctx;
-
-	/* The encryption operation will require a bounce page. */
-	ciphertext_page = alloc_bounce_page(ctx, gfp_flags);
-	if (IS_ERR(ciphertext_page))
-		goto errout;
-	ctx->w.control_page = plaintext_page;
-	err = ext4_page_crypto(inode, EXT4_ENCRYPT, plaintext_page->index,
-			       plaintext_page, ciphertext_page, gfp_flags);
-	if (err) {
-		ciphertext_page = ERR_PTR(err);
-	errout:
-		ext4_release_crypto_ctx(ctx);
-		return ciphertext_page;
-	}
-	SetPagePrivate(ciphertext_page);
-	set_page_private(ciphertext_page, (unsigned long)ctx);
-	lock_page(ciphertext_page);
-	return ciphertext_page;
-}
-
-/**
- * ext4_decrypt() - Decrypts a page in-place
- * @ctx:  The encryption context.
- * @page: The page to decrypt. Must be locked.
- *
- * Decrypts page in-place using the ctx encryption context.
- *
- * Called from the read completion callback.
- *
- * Return: Zero on success, non-zero otherwise.
- */
-int ext4_decrypt(struct page *page)
-{
-	BUG_ON(!PageLocked(page));
-
-	return ext4_page_crypto(page->mapping->host, EXT4_DECRYPT,
-				page->index, page, page, GFP_NOFS);
-}
-
-int ext4_encrypted_zeroout(struct inode *inode, ext4_lblk_t lblk,
-			   ext4_fsblk_t pblk, ext4_lblk_t len)
-{
-	struct ext4_crypto_ctx	*ctx;
-	struct page		*ciphertext_page = NULL;
-	struct bio		*bio;
-	int			ret, err = 0;
-
-#if 0
-	ext4_msg(inode->i_sb, KERN_CRIT,
-		 "ext4_encrypted_zeroout ino %lu lblk %u len %u",
-		 (unsigned long) inode->i_ino, lblk, len);
-#endif
-
-	BUG_ON(inode->i_sb->s_blocksize != PAGE_SIZE);
-
-	ctx = ext4_get_crypto_ctx(inode, GFP_NOFS);
-	if (IS_ERR(ctx))
-		return PTR_ERR(ctx);
-
-	ciphertext_page = alloc_bounce_page(ctx, GFP_NOWAIT);
-	if (IS_ERR(ciphertext_page)) {
-		err = PTR_ERR(ciphertext_page);
-		goto errout;
-	}
-
-	while (len--) {
-		err = ext4_page_crypto(inode, EXT4_ENCRYPT, lblk,
-				       ZERO_PAGE(0), ciphertext_page,
-				       GFP_NOFS);
-		if (err)
-			goto errout;
-
-		bio = bio_alloc(GFP_NOWAIT, 1);
-		if (!bio) {
-			err = -ENOMEM;
-			goto errout;
-		}
-		bio->bi_bdev = inode->i_sb->s_bdev;
-		bio->bi_iter.bi_sector =
-			pblk << (inode->i_sb->s_blocksize_bits - 9);
-		ret = bio_add_page(bio, ciphertext_page,
-				   inode->i_sb->s_blocksize, 0);
-		if (ret != inode->i_sb->s_blocksize) {
-			/* should never happen! */
-			ext4_msg(inode->i_sb, KERN_ERR,
-				 "bio_add_page failed: %d", ret);
-			WARN_ON(1);
-			bio_put(bio);
-			err = -EIO;
-			goto errout;
-		}
-		err = submit_bio_wait(WRITE, bio);
-		if ((err == 0) && bio->bi_error)
-			err = -EIO;
-		bio_put(bio);
-		if (err)
-			goto errout;
-		lblk++; pblk++;
-	}
-	err = 0;
-errout:
-	ext4_release_crypto_ctx(ctx);
-	return err;
-}
-
-bool ext4_valid_contents_enc_mode(uint32_t mode)
-{
-	return (mode == EXT4_ENCRYPTION_MODE_AES_256_XTS);
-}
-
-/**
- * ext4_validate_encryption_key_size() - Validate the encryption key size
- * @mode: The key mode.
- * @size: The key size to validate.
- *
- * Return: The validated key size for @mode. Zero if invalid.
- */
-uint32_t ext4_validate_encryption_key_size(uint32_t mode, uint32_t size)
-{
-	if (size == ext4_encryption_key_size(mode))
-		return size;
-	return 0;
-}
-
-/*
- * Validate dentries for encrypted directories to make sure we aren't
- * potentially caching stale data after a key has been added or
- * removed.
- */
-static int ext4_d_revalidate(struct dentry *dentry, unsigned int flags)
-{
-	struct dentry *dir;
-	struct ext4_crypt_info *ci;
-	int dir_has_key, cached_with_key;
-
-	if (flags & LOOKUP_RCU)
-		return -ECHILD;
-
-	dir = dget_parent(dentry);
-	if (!ext4_encrypted_inode(d_inode(dir))) {
-		dput(dir);
-		return 0;
-	}
-	ci = EXT4_I(d_inode(dir))->i_crypt_info;
-	if (ci && ci->ci_keyring_key &&
-	    (ci->ci_keyring_key->flags & ((1 << KEY_FLAG_INVALIDATED) |
-					  (1 << KEY_FLAG_REVOKED) |
-					  (1 << KEY_FLAG_DEAD))))
-		ci = NULL;
-
-	/* this should eventually be an flag in d_flags */
-	cached_with_key = dentry->d_fsdata != NULL;
-	dir_has_key = (ci != NULL);
-	dput(dir);
-
-	/*
-	 * If the dentry was cached without the key, and it is a
-	 * negative dentry, it might be a valid name.  We can't check
-	 * if the key has since been made available due to locking
-	 * reasons, so we fail the validation so ext4_lookup() can do
-	 * this check.
-	 *
-	 * We also fail the validation if the dentry was created with
-	 * the key present, but we no longer have the key, or vice versa.
-	 */
-	if ((!cached_with_key && d_is_negative(dentry)) ||
-	    (!cached_with_key && dir_has_key) ||
-	    (cached_with_key && !dir_has_key)) {
-#if 0				/* Revalidation debug */
-		char buf[80];
-		char *cp = simple_dname(dentry, buf, sizeof(buf));
-
-		if (IS_ERR(cp))
-			cp = (char *) "???";
-		pr_err("revalidate: %s %p %d %d %d\n", cp, dentry->d_fsdata,
-		       cached_with_key, d_is_negative(dentry),
-		       dir_has_key);
-#endif
-		return 0;
-	}
-	return 1;
-}
-
-const struct dentry_operations ext4_encrypted_d_ops = {
-	.d_revalidate = ext4_d_revalidate,
-};
diff --git a/fs/ext4/crypto_fname.c b/fs/ext4/crypto_fname.c
deleted file mode 100644
index 1a2f360..0000000
--- a/fs/ext4/crypto_fname.c
+++ /dev/null
@@ -1,468 +0,0 @@
-/*
- * linux/fs/ext4/crypto_fname.c
- *
- * Copyright (C) 2015, Google, Inc.
- *
- * This contains functions for filename crypto management in ext4
- *
- * Written by Uday Savagaonkar, 2014.
- *
- * This has not yet undergone a rigorous security audit.
- *
- */
-
-#include <crypto/skcipher.h>
-#include <keys/encrypted-type.h>
-#include <keys/user-type.h>
-#include <linux/gfp.h>
-#include <linux/kernel.h>
-#include <linux/key.h>
-#include <linux/list.h>
-#include <linux/mempool.h>
-#include <linux/random.h>
-#include <linux/scatterlist.h>
-#include <linux/spinlock_types.h>
-
-#include "ext4.h"
-#include "ext4_crypto.h"
-#include "xattr.h"
-
-/**
- * ext4_dir_crypt_complete() -
- */
-static void ext4_dir_crypt_complete(struct crypto_async_request *req, int res)
-{
-	struct ext4_completion_result *ecr = req->data;
-
-	if (res == -EINPROGRESS)
-		return;
-	ecr->res = res;
-	complete(&ecr->completion);
-}
-
-bool ext4_valid_filenames_enc_mode(uint32_t mode)
-{
-	return (mode == EXT4_ENCRYPTION_MODE_AES_256_CTS);
-}
-
-static unsigned max_name_len(struct inode *inode)
-{
-	return S_ISLNK(inode->i_mode) ? inode->i_sb->s_blocksize :
-		EXT4_NAME_LEN;
-}
-
-/**
- * ext4_fname_encrypt() -
- *
- * This function encrypts the input filename, and returns the length of the
- * ciphertext. Errors are returned as negative numbers.  We trust the caller to
- * allocate sufficient memory to oname string.
- */
-static int ext4_fname_encrypt(struct inode *inode,
-			      const struct qstr *iname,
-			      struct ext4_str *oname)
-{
-	u32 ciphertext_len;
-	struct skcipher_request *req = NULL;
-	DECLARE_EXT4_COMPLETION_RESULT(ecr);
-	struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info;
-	struct crypto_skcipher *tfm = ci->ci_ctfm;
-	int res = 0;
-	char iv[EXT4_CRYPTO_BLOCK_SIZE];
-	struct scatterlist src_sg, dst_sg;
-	int padding = 4 << (ci->ci_flags & EXT4_POLICY_FLAGS_PAD_MASK);
-	char *workbuf, buf[32], *alloc_buf = NULL;
-	unsigned lim = max_name_len(inode);
-
-	if (iname->len <= 0 || iname->len > lim)
-		return -EIO;
-
-	ciphertext_len = (iname->len < EXT4_CRYPTO_BLOCK_SIZE) ?
-		EXT4_CRYPTO_BLOCK_SIZE : iname->len;
-	ciphertext_len = ext4_fname_crypto_round_up(ciphertext_len, padding);
-	ciphertext_len = (ciphertext_len > lim)
-			? lim : ciphertext_len;
-
-	if (ciphertext_len <= sizeof(buf)) {
-		workbuf = buf;
-	} else {
-		alloc_buf = kmalloc(ciphertext_len, GFP_NOFS);
-		if (!alloc_buf)
-			return -ENOMEM;
-		workbuf = alloc_buf;
-	}
-
-	/* Allocate request */
-	req = skcipher_request_alloc(tfm, GFP_NOFS);
-	if (!req) {
-		printk_ratelimited(
-		    KERN_ERR "%s: crypto_request_alloc() failed\n", __func__);
-		kfree(alloc_buf);
-		return -ENOMEM;
-	}
-	skcipher_request_set_callback(req,
-		CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
-		ext4_dir_crypt_complete, &ecr);
-
-	/* Copy the input */
-	memcpy(workbuf, iname->name, iname->len);
-	if (iname->len < ciphertext_len)
-		memset(workbuf + iname->len, 0, ciphertext_len - iname->len);
-
-	/* Initialize IV */
-	memset(iv, 0, EXT4_CRYPTO_BLOCK_SIZE);
-
-	/* Create encryption request */
-	sg_init_one(&src_sg, workbuf, ciphertext_len);
-	sg_init_one(&dst_sg, oname->name, ciphertext_len);
-	skcipher_request_set_crypt(req, &src_sg, &dst_sg, ciphertext_len, iv);
-	res = crypto_skcipher_encrypt(req);
-	if (res == -EINPROGRESS || res == -EBUSY) {
-		wait_for_completion(&ecr.completion);
-		res = ecr.res;
-	}
-	kfree(alloc_buf);
-	skcipher_request_free(req);
-	if (res < 0) {
-		printk_ratelimited(
-		    KERN_ERR "%s: Error (error code %d)\n", __func__, res);
-	}
-	oname->len = ciphertext_len;
-	return res;
-}
-
-/*
- * ext4_fname_decrypt()
- *	This function decrypts the input filename, and returns
- *	the length of the plaintext.
- *	Errors are returned as negative numbers.
- *	We trust the caller to allocate sufficient memory to oname string.
- */
-static int ext4_fname_decrypt(struct inode *inode,
-			      const struct ext4_str *iname,
-			      struct ext4_str *oname)
-{
-	struct ext4_str tmp_in[2], tmp_out[1];
-	struct skcipher_request *req = NULL;
-	DECLARE_EXT4_COMPLETION_RESULT(ecr);
-	struct scatterlist src_sg, dst_sg;
-	struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info;
-	struct crypto_skcipher *tfm = ci->ci_ctfm;
-	int res = 0;
-	char iv[EXT4_CRYPTO_BLOCK_SIZE];
-	unsigned lim = max_name_len(inode);
-
-	if (iname->len <= 0 || iname->len > lim)
-		return -EIO;
-
-	tmp_in[0].name = iname->name;
-	tmp_in[0].len = iname->len;
-	tmp_out[0].name = oname->name;
-
-	/* Allocate request */
-	req = skcipher_request_alloc(tfm, GFP_NOFS);
-	if (!req) {
-		printk_ratelimited(
-		    KERN_ERR "%s: crypto_request_alloc() failed\n",  __func__);
-		return -ENOMEM;
-	}
-	skcipher_request_set_callback(req,
-		CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
-		ext4_dir_crypt_complete, &ecr);
-
-	/* Initialize IV */
-	memset(iv, 0, EXT4_CRYPTO_BLOCK_SIZE);
-
-	/* Create encryption request */
-	sg_init_one(&src_sg, iname->name, iname->len);
-	sg_init_one(&dst_sg, oname->name, oname->len);
-	skcipher_request_set_crypt(req, &src_sg, &dst_sg, iname->len, iv);
-	res = crypto_skcipher_decrypt(req);
-	if (res == -EINPROGRESS || res == -EBUSY) {
-		wait_for_completion(&ecr.completion);
-		res = ecr.res;
-	}
-	skcipher_request_free(req);
-	if (res < 0) {
-		printk_ratelimited(
-		    KERN_ERR "%s: Error in ext4_fname_encrypt (error code %d)\n",
-		    __func__, res);
-		return res;
-	}
-
-	oname->len = strnlen(oname->name, iname->len);
-	return oname->len;
-}
-
-static const char *lookup_table =
-	"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+,";
-
-/**
- * ext4_fname_encode_digest() -
- *
- * Encodes the input digest using characters from the set [a-zA-Z0-9_+].
- * The encoded string is roughly 4/3 times the size of the input string.
- */
-static int digest_encode(const char *src, int len, char *dst)
-{
-	int i = 0, bits = 0, ac = 0;
-	char *cp = dst;
-
-	while (i < len) {
-		ac += (((unsigned char) src[i]) << bits);
-		bits += 8;
-		do {
-			*cp++ = lookup_table[ac & 0x3f];
-			ac >>= 6;
-			bits -= 6;
-		} while (bits >= 6);
-		i++;
-	}
-	if (bits)
-		*cp++ = lookup_table[ac & 0x3f];
-	return cp - dst;
-}
-
-static int digest_decode(const char *src, int len, char *dst)
-{
-	int i = 0, bits = 0, ac = 0;
-	const char *p;
-	char *cp = dst;
-
-	while (i < len) {
-		p = strchr(lookup_table, src[i]);
-		if (p == NULL || src[i] == 0)
-			return -2;
-		ac += (p - lookup_table) << bits;
-		bits += 6;
-		if (bits >= 8) {
-			*cp++ = ac & 0xff;
-			ac >>= 8;
-			bits -= 8;
-		}
-		i++;
-	}
-	if (ac)
-		return -1;
-	return cp - dst;
-}
-
-/**
- * ext4_fname_crypto_round_up() -
- *
- * Return: The next multiple of block size
- */
-u32 ext4_fname_crypto_round_up(u32 size, u32 blksize)
-{
-	return ((size+blksize-1)/blksize)*blksize;
-}
-
-unsigned ext4_fname_encrypted_size(struct inode *inode, u32 ilen)
-{
-	struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info;
-	int padding = 32;
-
-	if (ci)
-		padding = 4 << (ci->ci_flags & EXT4_POLICY_FLAGS_PAD_MASK);
-	if (ilen < EXT4_CRYPTO_BLOCK_SIZE)
-		ilen = EXT4_CRYPTO_BLOCK_SIZE;
-	return ext4_fname_crypto_round_up(ilen, padding);
-}
-
-/*
- * ext4_fname_crypto_alloc_buffer() -
- *
- * Allocates an output buffer that is sufficient for the crypto operation
- * specified by the context and the direction.
- */
-int ext4_fname_crypto_alloc_buffer(struct inode *inode,
-				   u32 ilen, struct ext4_str *crypto_str)
-{
-	unsigned int olen = ext4_fname_encrypted_size(inode, ilen);
-
-	crypto_str->len = olen;
-	if (olen < EXT4_FNAME_CRYPTO_DIGEST_SIZE*2)
-		olen = EXT4_FNAME_CRYPTO_DIGEST_SIZE*2;
-	/* Allocated buffer can hold one more character to null-terminate the
-	 * string */
-	crypto_str->name = kmalloc(olen+1, GFP_NOFS);
-	if (!(crypto_str->name))
-		return -ENOMEM;
-	return 0;
-}
-
-/**
- * ext4_fname_crypto_free_buffer() -
- *
- * Frees the buffer allocated for crypto operation.
- */
-void ext4_fname_crypto_free_buffer(struct ext4_str *crypto_str)
-{
-	if (!crypto_str)
-		return;
-	kfree(crypto_str->name);
-	crypto_str->name = NULL;
-}
-
-/**
- * ext4_fname_disk_to_usr() - converts a filename from disk space to user space
- */
-int _ext4_fname_disk_to_usr(struct inode *inode,
-			    struct dx_hash_info *hinfo,
-			    const struct ext4_str *iname,
-			    struct ext4_str *oname)
-{
-	char buf[24];
-	int ret;
-
-	if (iname->len < 3) {
-		/*Check for . and .. */
-		if (iname->name[0] == '.' && iname->name[iname->len-1] == '.') {
-			oname->name[0] = '.';
-			oname->name[iname->len-1] = '.';
-			oname->len = iname->len;
-			return oname->len;
-		}
-	}
-	if (iname->len < EXT4_CRYPTO_BLOCK_SIZE) {
-		EXT4_ERROR_INODE(inode, "encrypted inode too small");
-		return -EUCLEAN;
-	}
-	if (EXT4_I(inode)->i_crypt_info)
-		return ext4_fname_decrypt(inode, iname, oname);
-
-	if (iname->len <= EXT4_FNAME_CRYPTO_DIGEST_SIZE) {
-		ret = digest_encode(iname->name, iname->len, oname->name);
-		oname->len = ret;
-		return ret;
-	}
-	if (hinfo) {
-		memcpy(buf, &hinfo->hash, 4);
-		memcpy(buf+4, &hinfo->minor_hash, 4);
-	} else
-		memset(buf, 0, 8);
-	memcpy(buf + 8, iname->name + iname->len - 16, 16);
-	oname->name[0] = '_';
-	ret = digest_encode(buf, 24, oname->name+1);
-	oname->len = ret + 1;
-	return ret + 1;
-}
-
-int ext4_fname_disk_to_usr(struct inode *inode,
-			   struct dx_hash_info *hinfo,
-			   const struct ext4_dir_entry_2 *de,
-			   struct ext4_str *oname)
-{
-	struct ext4_str iname = {.name = (unsigned char *) de->name,
-				 .len = de->name_len };
-
-	return _ext4_fname_disk_to_usr(inode, hinfo, &iname, oname);
-}
-
-
-/**
- * ext4_fname_usr_to_disk() - converts a filename from user space to disk space
- */
-int ext4_fname_usr_to_disk(struct inode *inode,
-			   const struct qstr *iname,
-			   struct ext4_str *oname)
-{
-	int res;
-	struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info;
-
-	if (iname->len < 3) {
-		/*Check for . and .. */
-		if (iname->name[0] == '.' &&
-				iname->name[iname->len-1] == '.') {
-			oname->name[0] = '.';
-			oname->name[iname->len-1] = '.';
-			oname->len = iname->len;
-			return oname->len;
-		}
-	}
-	if (ci) {
-		res = ext4_fname_encrypt(inode, iname, oname);
-		return res;
-	}
-	/* Without a proper key, a user is not allowed to modify the filenames
-	 * in a directory. Consequently, a user space name cannot be mapped to
-	 * a disk-space name */
-	return -EACCES;
-}
-
-int ext4_fname_setup_filename(struct inode *dir, const struct qstr *iname,
-			      int lookup, struct ext4_filename *fname)
-{
-	struct ext4_crypt_info *ci;
-	int ret = 0, bigname = 0;
-
-	memset(fname, 0, sizeof(struct ext4_filename));
-	fname->usr_fname = iname;
-
-	if (!ext4_encrypted_inode(dir) ||
-	    ((iname->name[0] == '.') &&
-	     ((iname->len == 1) ||
-	      ((iname->name[1] == '.') && (iname->len == 2))))) {
-		fname->disk_name.name = (unsigned char *) iname->name;
-		fname->disk_name.len = iname->len;
-		return 0;
-	}
-	ret = ext4_get_encryption_info(dir);
-	if (ret)
-		return ret;
-	ci = EXT4_I(dir)->i_crypt_info;
-	if (ci) {
-		ret = ext4_fname_crypto_alloc_buffer(dir, iname->len,
-						     &fname->crypto_buf);
-		if (ret < 0)
-			return ret;
-		ret = ext4_fname_encrypt(dir, iname, &fname->crypto_buf);
-		if (ret < 0)
-			goto errout;
-		fname->disk_name.name = fname->crypto_buf.name;
-		fname->disk_name.len = fname->crypto_buf.len;
-		return 0;
-	}
-	if (!lookup)
-		return -EACCES;
-
-	/* We don't have the key and we are doing a lookup; decode the
-	 * user-supplied name
-	 */
-	if (iname->name[0] == '_')
-		bigname = 1;
-	if ((bigname && (iname->len != 33)) ||
-	    (!bigname && (iname->len > 43)))
-		return -ENOENT;
-
-	fname->crypto_buf.name = kmalloc(32, GFP_KERNEL);
-	if (fname->crypto_buf.name == NULL)
-		return -ENOMEM;
-	ret = digest_decode(iname->name + bigname, iname->len - bigname,
-			    fname->crypto_buf.name);
-	if (ret < 0) {
-		ret = -ENOENT;
-		goto errout;
-	}
-	fname->crypto_buf.len = ret;
-	if (bigname) {
-		memcpy(&fname->hinfo.hash, fname->crypto_buf.name, 4);
-		memcpy(&fname->hinfo.minor_hash, fname->crypto_buf.name + 4, 4);
-	} else {
-		fname->disk_name.name = fname->crypto_buf.name;
-		fname->disk_name.len = fname->crypto_buf.len;
-	}
-	return 0;
-errout:
-	kfree(fname->crypto_buf.name);
-	fname->crypto_buf.name = NULL;
-	return ret;
-}
-
-void ext4_fname_free_filename(struct ext4_filename *fname)
-{
-	kfree(fname->crypto_buf.name);
-	fname->crypto_buf.name = NULL;
-	fname->usr_fname = NULL;
-	fname->disk_name.name = NULL;
-}
diff --git a/fs/ext4/crypto_key.c b/fs/ext4/crypto_key.c
deleted file mode 100644
index 0129d68..0000000
--- a/fs/ext4/crypto_key.c
+++ /dev/null
@@ -1,274 +0,0 @@
-/*
- * linux/fs/ext4/crypto_key.c
- *
- * Copyright (C) 2015, Google, Inc.
- *
- * This contains encryption key functions for ext4
- *
- * Written by Michael Halcrow, Ildar Muslukhov, and Uday Savagaonkar, 2015.
- */
-
-#include <crypto/skcipher.h>
-#include <keys/encrypted-type.h>
-#include <keys/user-type.h>
-#include <linux/random.h>
-#include <linux/scatterlist.h>
-#include <uapi/linux/keyctl.h>
-
-#include "ext4.h"
-#include "xattr.h"
-
-static void derive_crypt_complete(struct crypto_async_request *req, int rc)
-{
-	struct ext4_completion_result *ecr = req->data;
-
-	if (rc == -EINPROGRESS)
-		return;
-
-	ecr->res = rc;
-	complete(&ecr->completion);
-}
-
-/**
- * ext4_derive_key_aes() - Derive a key using AES-128-ECB
- * @deriving_key: Encryption key used for derivation.
- * @source_key:   Source key to which to apply derivation.
- * @derived_key:  Derived key.
- *
- * Return: Zero on success; non-zero otherwise.
- */
-static int ext4_derive_key_aes(char deriving_key[EXT4_AES_128_ECB_KEY_SIZE],
-			       char source_key[EXT4_AES_256_XTS_KEY_SIZE],
-			       char derived_key[EXT4_AES_256_XTS_KEY_SIZE])
-{
-	int res = 0;
-	struct skcipher_request *req = NULL;
-	DECLARE_EXT4_COMPLETION_RESULT(ecr);
-	struct scatterlist src_sg, dst_sg;
-	struct crypto_skcipher *tfm = crypto_alloc_skcipher("ecb(aes)", 0, 0);
-
-	if (IS_ERR(tfm)) {
-		res = PTR_ERR(tfm);
-		tfm = NULL;
-		goto out;
-	}
-	crypto_skcipher_set_flags(tfm, CRYPTO_TFM_REQ_WEAK_KEY);
-	req = skcipher_request_alloc(tfm, GFP_NOFS);
-	if (!req) {
-		res = -ENOMEM;
-		goto out;
-	}
-	skcipher_request_set_callback(req,
-			CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
-			derive_crypt_complete, &ecr);
-	res = crypto_skcipher_setkey(tfm, deriving_key,
-				     EXT4_AES_128_ECB_KEY_SIZE);
-	if (res < 0)
-		goto out;
-	sg_init_one(&src_sg, source_key, EXT4_AES_256_XTS_KEY_SIZE);
-	sg_init_one(&dst_sg, derived_key, EXT4_AES_256_XTS_KEY_SIZE);
-	skcipher_request_set_crypt(req, &src_sg, &dst_sg,
-				   EXT4_AES_256_XTS_KEY_SIZE, NULL);
-	res = crypto_skcipher_encrypt(req);
-	if (res == -EINPROGRESS || res == -EBUSY) {
-		wait_for_completion(&ecr.completion);
-		res = ecr.res;
-	}
-
-out:
-	skcipher_request_free(req);
-	crypto_free_skcipher(tfm);
-	return res;
-}
-
-void ext4_free_crypt_info(struct ext4_crypt_info *ci)
-{
-	if (!ci)
-		return;
-
-	if (ci->ci_keyring_key)
-		key_put(ci->ci_keyring_key);
-	crypto_free_skcipher(ci->ci_ctfm);
-	kmem_cache_free(ext4_crypt_info_cachep, ci);
-}
-
-void ext4_free_encryption_info(struct inode *inode,
-			       struct ext4_crypt_info *ci)
-{
-	struct ext4_inode_info *ei = EXT4_I(inode);
-	struct ext4_crypt_info *prev;
-
-	if (ci == NULL)
-		ci = ACCESS_ONCE(ei->i_crypt_info);
-	if (ci == NULL)
-		return;
-	prev = cmpxchg(&ei->i_crypt_info, ci, NULL);
-	if (prev != ci)
-		return;
-
-	ext4_free_crypt_info(ci);
-}
-
-int _ext4_get_encryption_info(struct inode *inode)
-{
-	struct ext4_inode_info *ei = EXT4_I(inode);
-	struct ext4_crypt_info *crypt_info;
-	char full_key_descriptor[EXT4_KEY_DESC_PREFIX_SIZE +
-				 (EXT4_KEY_DESCRIPTOR_SIZE * 2) + 1];
-	struct key *keyring_key = NULL;
-	struct ext4_encryption_key *master_key;
-	struct ext4_encryption_context ctx;
-	const struct user_key_payload *ukp;
-	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
-	struct crypto_skcipher *ctfm;
-	const char *cipher_str;
-	char raw_key[EXT4_MAX_KEY_SIZE];
-	char mode;
-	int res;
-
-	if (!ext4_read_workqueue) {
-		res = ext4_init_crypto();
-		if (res)
-			return res;
-	}
-
-retry:
-	crypt_info = ACCESS_ONCE(ei->i_crypt_info);
-	if (crypt_info) {
-		if (!crypt_info->ci_keyring_key ||
-		    key_validate(crypt_info->ci_keyring_key) == 0)
-			return 0;
-		ext4_free_encryption_info(inode, crypt_info);
-		goto retry;
-	}
-
-	res = ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
-				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
-				 &ctx, sizeof(ctx));
-	if (res < 0) {
-		if (!DUMMY_ENCRYPTION_ENABLED(sbi))
-			return res;
-		ctx.contents_encryption_mode = EXT4_ENCRYPTION_MODE_AES_256_XTS;
-		ctx.filenames_encryption_mode =
-			EXT4_ENCRYPTION_MODE_AES_256_CTS;
-		ctx.flags = 0;
-	} else if (res != sizeof(ctx))
-		return -EINVAL;
-	res = 0;
-
-	crypt_info = kmem_cache_alloc(ext4_crypt_info_cachep, GFP_KERNEL);
-	if (!crypt_info)
-		return -ENOMEM;
-
-	crypt_info->ci_flags = ctx.flags;
-	crypt_info->ci_data_mode = ctx.contents_encryption_mode;
-	crypt_info->ci_filename_mode = ctx.filenames_encryption_mode;
-	crypt_info->ci_ctfm = NULL;
-	crypt_info->ci_keyring_key = NULL;
-	memcpy(crypt_info->ci_master_key, ctx.master_key_descriptor,
-	       sizeof(crypt_info->ci_master_key));
-	if (S_ISREG(inode->i_mode))
-		mode = crypt_info->ci_data_mode;
-	else if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
-		mode = crypt_info->ci_filename_mode;
-	else
-		BUG();
-	switch (mode) {
-	case EXT4_ENCRYPTION_MODE_AES_256_XTS:
-		cipher_str = "xts(aes)";
-		break;
-	case EXT4_ENCRYPTION_MODE_AES_256_CTS:
-		cipher_str = "cts(cbc(aes))";
-		break;
-	default:
-		printk_once(KERN_WARNING
-			    "ext4: unsupported key mode %d (ino %u)\n",
-			    mode, (unsigned) inode->i_ino);
-		res = -ENOKEY;
-		goto out;
-	}
-	if (DUMMY_ENCRYPTION_ENABLED(sbi)) {
-		memset(raw_key, 0x42, EXT4_AES_256_XTS_KEY_SIZE);
-		goto got_key;
-	}
-	memcpy(full_key_descriptor, EXT4_KEY_DESC_PREFIX,
-	       EXT4_KEY_DESC_PREFIX_SIZE);
-	sprintf(full_key_descriptor + EXT4_KEY_DESC_PREFIX_SIZE,
-		"%*phN", EXT4_KEY_DESCRIPTOR_SIZE,
-		ctx.master_key_descriptor);
-	full_key_descriptor[EXT4_KEY_DESC_PREFIX_SIZE +
-			    (2 * EXT4_KEY_DESCRIPTOR_SIZE)] = '\0';
-	keyring_key = request_key(&key_type_logon, full_key_descriptor, NULL);
-	if (IS_ERR(keyring_key)) {
-		res = PTR_ERR(keyring_key);
-		keyring_key = NULL;
-		goto out;
-	}
-	crypt_info->ci_keyring_key = keyring_key;
-	if (keyring_key->type != &key_type_logon) {
-		printk_once(KERN_WARNING
-			    "ext4: key type must be logon\n");
-		res = -ENOKEY;
-		goto out;
-	}
-	down_read(&keyring_key->sem);
-	ukp = user_key_payload(keyring_key);
-	if (ukp->datalen != sizeof(struct ext4_encryption_key)) {
-		res = -EINVAL;
-		up_read(&keyring_key->sem);
-		goto out;
-	}
-	master_key = (struct ext4_encryption_key *)ukp->data;
-	BUILD_BUG_ON(EXT4_AES_128_ECB_KEY_SIZE !=
-		     EXT4_KEY_DERIVATION_NONCE_SIZE);
-	if (master_key->size != EXT4_AES_256_XTS_KEY_SIZE) {
-		printk_once(KERN_WARNING
-			    "ext4: key size incorrect: %d\n",
-			    master_key->size);
-		res = -ENOKEY;
-		up_read(&keyring_key->sem);
-		goto out;
-	}
-	res = ext4_derive_key_aes(ctx.nonce, master_key->raw,
-				  raw_key);
-	up_read(&keyring_key->sem);
-	if (res)
-		goto out;
-got_key:
-	ctfm = crypto_alloc_skcipher(cipher_str, 0, 0);
-	if (!ctfm || IS_ERR(ctfm)) {
-		res = ctfm ? PTR_ERR(ctfm) : -ENOMEM;
-		printk(KERN_DEBUG
-		       "%s: error %d (inode %u) allocating crypto tfm\n",
-		       __func__, res, (unsigned) inode->i_ino);
-		goto out;
-	}
-	crypt_info->ci_ctfm = ctfm;
-	crypto_skcipher_clear_flags(ctfm, ~0);
-	crypto_tfm_set_flags(crypto_skcipher_tfm(ctfm),
-			     CRYPTO_TFM_REQ_WEAK_KEY);
-	res = crypto_skcipher_setkey(ctfm, raw_key,
-				     ext4_encryption_key_size(mode));
-	if (res)
-		goto out;
-	memzero_explicit(raw_key, sizeof(raw_key));
-	if (cmpxchg(&ei->i_crypt_info, NULL, crypt_info) != NULL) {
-		ext4_free_crypt_info(crypt_info);
-		goto retry;
-	}
-	return 0;
-
-out:
-	if (res == -ENOKEY)
-		res = 0;
-	ext4_free_crypt_info(crypt_info);
-	memzero_explicit(raw_key, sizeof(raw_key));
-	return res;
-}
-
-int ext4_has_encryption_key(struct inode *inode)
-{
-	struct ext4_inode_info *ei = EXT4_I(inode);
-
-	return (ei->i_crypt_info != NULL);
-}
diff --git a/fs/ext4/crypto_policy.c b/fs/ext4/crypto_policy.c
deleted file mode 100644
index ad05069..0000000
--- a/fs/ext4/crypto_policy.c
+++ /dev/null
@@ -1,229 +0,0 @@
-/*
- * linux/fs/ext4/crypto_policy.c
- *
- * Copyright (C) 2015, Google, Inc.
- *
- * This contains encryption policy functions for ext4
- *
- * Written by Michael Halcrow, 2015.
- */
-
-#include <linux/random.h>
-#include <linux/string.h>
-#include <linux/types.h>
-
-#include "ext4_jbd2.h"
-#include "ext4.h"
-#include "xattr.h"
-
-static int ext4_inode_has_encryption_context(struct inode *inode)
-{
-	int res = ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
-				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, NULL, 0);
-	return (res > 0);
-}
-
-/*
- * check whether the policy is consistent with the encryption context
- * for the inode
- */
-static int ext4_is_encryption_context_consistent_with_policy(
-	struct inode *inode, const struct ext4_encryption_policy *policy)
-{
-	struct ext4_encryption_context ctx;
-	int res = ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
-				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, &ctx,
-				 sizeof(ctx));
-	if (res != sizeof(ctx))
-		return 0;
-	return (memcmp(ctx.master_key_descriptor, policy->master_key_descriptor,
-			EXT4_KEY_DESCRIPTOR_SIZE) == 0 &&
-		(ctx.flags ==
-		 policy->flags) &&
-		(ctx.contents_encryption_mode ==
-		 policy->contents_encryption_mode) &&
-		(ctx.filenames_encryption_mode ==
-		 policy->filenames_encryption_mode));
-}
-
-static int ext4_create_encryption_context_from_policy(
-	struct inode *inode, const struct ext4_encryption_policy *policy)
-{
-	struct ext4_encryption_context ctx;
-	handle_t *handle;
-	int res, res2;
-
-	res = ext4_convert_inline_data(inode);
-	if (res)
-		return res;
-
-	ctx.format = EXT4_ENCRYPTION_CONTEXT_FORMAT_V1;
-	memcpy(ctx.master_key_descriptor, policy->master_key_descriptor,
-	       EXT4_KEY_DESCRIPTOR_SIZE);
-	if (!ext4_valid_contents_enc_mode(policy->contents_encryption_mode)) {
-		printk(KERN_WARNING
-		       "%s: Invalid contents encryption mode %d\n", __func__,
-			policy->contents_encryption_mode);
-		return -EINVAL;
-	}
-	if (!ext4_valid_filenames_enc_mode(policy->filenames_encryption_mode)) {
-		printk(KERN_WARNING
-		       "%s: Invalid filenames encryption mode %d\n", __func__,
-			policy->filenames_encryption_mode);
-		return -EINVAL;
-	}
-	if (policy->flags & ~EXT4_POLICY_FLAGS_VALID)
-		return -EINVAL;
-	ctx.contents_encryption_mode = policy->contents_encryption_mode;
-	ctx.filenames_encryption_mode = policy->filenames_encryption_mode;
-	ctx.flags = policy->flags;
-	BUILD_BUG_ON(sizeof(ctx.nonce) != EXT4_KEY_DERIVATION_NONCE_SIZE);
-	get_random_bytes(ctx.nonce, EXT4_KEY_DERIVATION_NONCE_SIZE);
-
-	handle = ext4_journal_start(inode, EXT4_HT_MISC,
-				    ext4_jbd2_credits_xattr(inode));
-	if (IS_ERR(handle))
-		return PTR_ERR(handle);
-	res = ext4_xattr_set(inode, EXT4_XATTR_INDEX_ENCRYPTION,
-			     EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, &ctx,
-			     sizeof(ctx), 0);
-	if (!res) {
-		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
-		res = ext4_mark_inode_dirty(handle, inode);
-		if (res)
-			EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
-	}
-	res2 = ext4_journal_stop(handle);
-	if (!res)
-		res = res2;
-	return res;
-}
-
-int ext4_process_policy(const struct ext4_encryption_policy *policy,
-			struct inode *inode)
-{
-	if (policy->version != 0)
-		return -EINVAL;
-
-	if (!ext4_inode_has_encryption_context(inode)) {
-		if (!S_ISDIR(inode->i_mode))
-			return -EINVAL;
-		if (!ext4_empty_dir(inode))
-			return -ENOTEMPTY;
-		return ext4_create_encryption_context_from_policy(inode,
-								  policy);
-	}
-
-	if (ext4_is_encryption_context_consistent_with_policy(inode, policy))
-		return 0;
-
-	printk(KERN_WARNING "%s: Policy inconsistent with encryption context\n",
-	       __func__);
-	return -EINVAL;
-}
-
-int ext4_get_policy(struct inode *inode, struct ext4_encryption_policy *policy)
-{
-	struct ext4_encryption_context ctx;
-
-	int res = ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
-				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
-				 &ctx, sizeof(ctx));
-	if (res != sizeof(ctx))
-		return -ENOENT;
-	if (ctx.format != EXT4_ENCRYPTION_CONTEXT_FORMAT_V1)
-		return -EINVAL;
-	policy->version = 0;
-	policy->contents_encryption_mode = ctx.contents_encryption_mode;
-	policy->filenames_encryption_mode = ctx.filenames_encryption_mode;
-	policy->flags = ctx.flags;
-	memcpy(&policy->master_key_descriptor, ctx.master_key_descriptor,
-	       EXT4_KEY_DESCRIPTOR_SIZE);
-	return 0;
-}
-
-int ext4_is_child_context_consistent_with_parent(struct inode *parent,
-						 struct inode *child)
-{
-	struct ext4_crypt_info *parent_ci, *child_ci;
-	int res;
-
-	if ((parent == NULL) || (child == NULL)) {
-		pr_err("parent %p child %p\n", parent, child);
-		WARN_ON(1);	/* Should never happen */
-		return 0;
-	}
-	/* no restrictions if the parent directory is not encrypted */
-	if (!ext4_encrypted_inode(parent))
-		return 1;
-	/* if the child directory is not encrypted, this is always a problem */
-	if (!ext4_encrypted_inode(child))
-		return 0;
-	res = ext4_get_encryption_info(parent);
-	if (res)
-		return 0;
-	res = ext4_get_encryption_info(child);
-	if (res)
-		return 0;
-	parent_ci = EXT4_I(parent)->i_crypt_info;
-	child_ci = EXT4_I(child)->i_crypt_info;
-	if (!parent_ci && !child_ci)
-		return 1;
-	if (!parent_ci || !child_ci)
-		return 0;
-
-	return (memcmp(parent_ci->ci_master_key,
-		       child_ci->ci_master_key,
-		       EXT4_KEY_DESCRIPTOR_SIZE) == 0 &&
-		(parent_ci->ci_data_mode == child_ci->ci_data_mode) &&
-		(parent_ci->ci_filename_mode == child_ci->ci_filename_mode) &&
-		(parent_ci->ci_flags == child_ci->ci_flags));
-}
-
-/**
- * ext4_inherit_context() - Sets a child context from its parent
- * @parent: Parent inode from which the context is inherited.
- * @child:  Child inode that inherits the context from @parent.
- *
- * Return: Zero on success, non-zero otherwise
- */
-int ext4_inherit_context(struct inode *parent, struct inode *child)
-{
-	struct ext4_encryption_context ctx;
-	struct ext4_crypt_info *ci;
-	int res;
-
-	res = ext4_get_encryption_info(parent);
-	if (res < 0)
-		return res;
-	ci = EXT4_I(parent)->i_crypt_info;
-	if (ci == NULL)
-		return -ENOKEY;
-
-	ctx.format = EXT4_ENCRYPTION_CONTEXT_FORMAT_V1;
-	if (DUMMY_ENCRYPTION_ENABLED(EXT4_SB(parent->i_sb))) {
-		ctx.contents_encryption_mode = EXT4_ENCRYPTION_MODE_AES_256_XTS;
-		ctx.filenames_encryption_mode =
-			EXT4_ENCRYPTION_MODE_AES_256_CTS;
-		ctx.flags = 0;
-		memset(ctx.master_key_descriptor, 0x42,
-		       EXT4_KEY_DESCRIPTOR_SIZE);
-		res = 0;
-	} else {
-		ctx.contents_encryption_mode = ci->ci_data_mode;
-		ctx.filenames_encryption_mode = ci->ci_filename_mode;
-		ctx.flags = ci->ci_flags;
-		memcpy(ctx.master_key_descriptor, ci->ci_master_key,
-		       EXT4_KEY_DESCRIPTOR_SIZE);
-	}
-	get_random_bytes(ctx.nonce, EXT4_KEY_DERIVATION_NONCE_SIZE);
-	res = ext4_xattr_set(child, EXT4_XATTR_INDEX_ENCRYPTION,
-			     EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, &ctx,
-			     sizeof(ctx), 0);
-	if (!res) {
-		ext4_set_inode_flag(child, EXT4_INODE_ENCRYPT);
-		ext4_clear_inode_state(child, EXT4_STATE_MAY_INLINE_DATA);
-		res = ext4_get_encryption_info(child);
-	}
-	return res;
-}
diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
index 68323e3..67415e0 100644
--- a/fs/ext4/dir.c
+++ b/fs/ext4/dir.c
@@ -109,10 +109,10 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx)
 	struct super_block *sb = inode->i_sb;
 	struct buffer_head *bh = NULL;
 	int dir_has_error = 0;
-	struct ext4_str fname_crypto_str = {.name = NULL, .len = 0};
+	struct fscrypt_str fstr = FSTR_INIT(NULL, 0);
 
 	if (ext4_encrypted_inode(inode)) {
-		err = ext4_get_encryption_info(inode);
+		err = fscrypt_get_encryption_info(inode);
 		if (err && err != -ENOKEY)
 			return err;
 	}
@@ -139,8 +139,7 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx)
 	}
 
 	if (ext4_encrypted_inode(inode)) {
-		err = ext4_fname_crypto_alloc_buffer(inode, EXT4_NAME_LEN,
-						     &fname_crypto_str);
+		err = fscrypt_fname_alloc_buffer(inode, EXT4_NAME_LEN, &fstr);
 		if (err < 0)
 			return err;
 	}
@@ -253,16 +252,19 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx)
 					    get_dtype(sb, de->file_type)))
 						goto done;
 				} else {
-					int save_len = fname_crypto_str.len;
+					int save_len = fstr.len;
+					struct fscrypt_str de_name =
+							FSTR_INIT(de->name,
+								de->name_len);
 
 					/* Directory is encrypted */
-					err = ext4_fname_disk_to_usr(inode,
-						NULL, de, &fname_crypto_str);
-					fname_crypto_str.len = save_len;
+					err = fscrypt_fname_disk_to_usr(inode,
+						0, 0, &de_name, &fstr);
+					fstr.len = save_len;
 					if (err < 0)
 						goto errout;
 					if (!dir_emit(ctx,
-					    fname_crypto_str.name, err,
+					    fstr.name, err,
 					    le32_to_cpu(de->inode),
 					    get_dtype(sb, de->file_type)))
 						goto done;
@@ -281,7 +283,7 @@ done:
 	err = 0;
 errout:
 #ifdef CONFIG_EXT4_FS_ENCRYPTION
-	ext4_fname_crypto_free_buffer(&fname_crypto_str);
+	fscrypt_fname_free_buffer(&fstr);
 #endif
 	brelse(bh);
 	return err;
@@ -432,7 +434,7 @@ void ext4_htree_free_dir_info(struct dir_private_info *p)
 int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
 			     __u32 minor_hash,
 			    struct ext4_dir_entry_2 *dirent,
-			    struct ext4_str *ent_name)
+			    struct fscrypt_str *ent_name)
 {
 	struct rb_node **p, *parent = NULL;
 	struct fname *fname, *new_fn;
@@ -609,7 +611,7 @@ finished:
 static int ext4_dir_open(struct inode * inode, struct file * filp)
 {
 	if (ext4_encrypted_inode(inode))
-		return ext4_get_encryption_info(inode) ? -EACCES : 0;
+		return fscrypt_get_encryption_info(inode) ? -EACCES : 0;
 	return 0;
 }
 
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 96c73e6..ea31931 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -32,6 +32,7 @@
 #include <linux/percpu_counter.h>
 #include <linux/ratelimit.h>
 #include <crypto/hash.h>
+#include <linux/fscrypto.h>
 #include <linux/falloc.h>
 #include <linux/percpu-rwsem.h>
 #ifdef __KERNEL__
@@ -608,15 +609,6 @@ enum {
 #define EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER	0x0010
 #define EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER	0x0020
 
-/* Encryption algorithms */
-#define EXT4_ENCRYPTION_MODE_INVALID		0
-#define EXT4_ENCRYPTION_MODE_AES_256_XTS	1
-#define EXT4_ENCRYPTION_MODE_AES_256_GCM	2
-#define EXT4_ENCRYPTION_MODE_AES_256_CBC	3
-#define EXT4_ENCRYPTION_MODE_AES_256_CTS	4
-
-#include "ext4_crypto.h"
-
 /*
  * ioctl commands
  */
@@ -638,9 +630,9 @@ enum {
 #define EXT4_IOC_RESIZE_FS		_IOW('f', 16, __u64)
 #define EXT4_IOC_SWAP_BOOT		_IO('f', 17)
 #define EXT4_IOC_PRECACHE_EXTENTS	_IO('f', 18)
-#define EXT4_IOC_SET_ENCRYPTION_POLICY	_IOR('f', 19, struct ext4_encryption_policy)
-#define EXT4_IOC_GET_ENCRYPTION_PWSALT	_IOW('f', 20, __u8[16])
-#define EXT4_IOC_GET_ENCRYPTION_POLICY	_IOW('f', 21, struct ext4_encryption_policy)
+#define EXT4_IOC_SET_ENCRYPTION_POLICY	FS_IOC_SET_ENCRYPTION_POLICY
+#define EXT4_IOC_GET_ENCRYPTION_PWSALT	FS_IOC_GET_ENCRYPTION_PWSALT
+#define EXT4_IOC_GET_ENCRYPTION_POLICY	FS_IOC_GET_ENCRYPTION_POLICY
 
 #ifndef FS_IOC_FSGETXATTR
 /* Until the uapi changes get merged for project quota... */
@@ -1082,10 +1074,6 @@ struct ext4_inode_info {
 	/* Precomputed uuid+inum+igen checksum for seeding inode checksums */
 	__u32 i_csum_seed;
 
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
-	/* Encryption params */
-	struct ext4_crypt_info *i_crypt_info;
-#endif
 	kprojid_t i_projid;
 };
 
@@ -1344,6 +1332,11 @@ struct ext4_super_block {
 /* Number of quota types we support */
 #define EXT4_MAXQUOTAS 3
 
+#ifdef CONFIG_EXT4_FS_ENCRYPTION
+#define EXT4_KEY_DESC_PREFIX "ext4:"
+#define EXT4_KEY_DESC_PREFIX_SIZE 5
+#endif
+
 /*
  * fourth extended-fs super-block data in memory
  */
@@ -1513,6 +1506,12 @@ struct ext4_sb_info {
 
 	/* Barrier between changing inodes' journal flags and writepages ops. */
 	struct percpu_rw_semaphore s_journal_flag_rwsem;
+
+	/* Encryption support */
+#ifdef CONFIG_EXT4_FS_ENCRYPTION
+	u8 key_prefix[EXT4_KEY_DESC_PREFIX_SIZE];
+	u8 key_prefix_size;
+#endif
 };
 
 static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
@@ -1611,15 +1610,6 @@ static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
 /*
  * Returns true if the inode is inode is encrypted
  */
-static inline int ext4_encrypted_inode(struct inode *inode)
-{
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
-	return ext4_test_inode_flag(inode, EXT4_INODE_ENCRYPT);
-#else
-	return 0;
-#endif
-}
-
 #define NEXT_ORPHAN(inode) EXT4_I(inode)->i_dtime
 
 /*
@@ -2083,10 +2073,10 @@ struct dx_hash_info
 
 struct ext4_filename {
 	const struct qstr *usr_fname;
-	struct ext4_str disk_name;
+	struct fscrypt_str disk_name;
 	struct dx_hash_info hinfo;
 #ifdef CONFIG_EXT4_FS_ENCRYPTION
-	struct ext4_str crypto_buf;
+	struct fscrypt_str crypto_buf;
 #endif
 };
 
@@ -2297,132 +2287,82 @@ extern unsigned ext4_free_clusters_after_init(struct super_block *sb,
 					      struct ext4_group_desc *gdp);
 ext4_fsblk_t ext4_inode_to_goal_block(struct inode *);
 
-/* crypto_policy.c */
-int ext4_is_child_context_consistent_with_parent(struct inode *parent,
-						 struct inode *child);
-int ext4_inherit_context(struct inode *parent, struct inode *child);
-void ext4_to_hex(char *dst, char *src, size_t src_size);
-int ext4_process_policy(const struct ext4_encryption_policy *policy,
-			struct inode *inode);
-int ext4_get_policy(struct inode *inode,
-		    struct ext4_encryption_policy *policy);
-
-/* crypto.c */
-extern struct kmem_cache *ext4_crypt_info_cachep;
-bool ext4_valid_contents_enc_mode(uint32_t mode);
-uint32_t ext4_validate_encryption_key_size(uint32_t mode, uint32_t size);
-extern struct workqueue_struct *ext4_read_workqueue;
-struct ext4_crypto_ctx *ext4_get_crypto_ctx(struct inode *inode,
-					    gfp_t gfp_flags);
-void ext4_release_crypto_ctx(struct ext4_crypto_ctx *ctx);
-void ext4_restore_control_page(struct page *data_page);
-struct page *ext4_encrypt(struct inode *inode,
-			  struct page *plaintext_page,
-			  gfp_t gfp_flags);
-int ext4_decrypt(struct page *page);
-int ext4_encrypted_zeroout(struct inode *inode, ext4_lblk_t lblk,
-			   ext4_fsblk_t pblk, ext4_lblk_t len);
-extern const struct dentry_operations ext4_encrypted_d_ops;
-
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
-int ext4_init_crypto(void);
-void ext4_exit_crypto(void);
 static inline int ext4_sb_has_crypto(struct super_block *sb)
 {
 	return ext4_has_feature_encrypt(sb);
 }
-#else
-static inline int ext4_init_crypto(void) { return 0; }
-static inline void ext4_exit_crypto(void) { }
-static inline int ext4_sb_has_crypto(struct super_block *sb)
+
+static inline bool ext4_encrypted_inode(struct inode *inode)
 {
-	return 0;
+	return ext4_test_inode_flag(inode, EXT4_INODE_ENCRYPT);
 }
-#endif
 
-/* crypto_fname.c */
-bool ext4_valid_filenames_enc_mode(uint32_t mode);
-u32 ext4_fname_crypto_round_up(u32 size, u32 blksize);
-unsigned ext4_fname_encrypted_size(struct inode *inode, u32 ilen);
-int ext4_fname_crypto_alloc_buffer(struct inode *inode,
-				   u32 ilen, struct ext4_str *crypto_str);
-int _ext4_fname_disk_to_usr(struct inode *inode,
-			    struct dx_hash_info *hinfo,
-			    const struct ext4_str *iname,
-			    struct ext4_str *oname);
-int ext4_fname_disk_to_usr(struct inode *inode,
-			   struct dx_hash_info *hinfo,
-			   const struct ext4_dir_entry_2 *de,
-			   struct ext4_str *oname);
-int ext4_fname_usr_to_disk(struct inode *inode,
-			   const struct qstr *iname,
-			   struct ext4_str *oname);
 #ifdef CONFIG_EXT4_FS_ENCRYPTION
-void ext4_fname_crypto_free_buffer(struct ext4_str *crypto_str);
-int ext4_fname_setup_filename(struct inode *dir, const struct qstr *iname,
-			      int lookup, struct ext4_filename *fname);
-void ext4_fname_free_filename(struct ext4_filename *fname);
-#else
-static inline
-int ext4_setup_fname_crypto(struct inode *inode)
-{
-	return 0;
-}
-static inline void ext4_fname_crypto_free_buffer(struct ext4_str *p) { }
 static inline int ext4_fname_setup_filename(struct inode *dir,
-				     const struct qstr *iname,
-				     int lookup, struct ext4_filename *fname)
+			const struct qstr *iname,
+			int lookup, struct ext4_filename *fname)
 {
-	fname->usr_fname = iname;
-	fname->disk_name.name = (unsigned char *) iname->name;
-	fname->disk_name.len = iname->len;
-	return 0;
-}
-static inline void ext4_fname_free_filename(struct ext4_filename *fname) { }
-#endif
-
+	struct fscrypt_name name;
+	int err;
 
-/* crypto_key.c */
-void ext4_free_crypt_info(struct ext4_crypt_info *ci);
-void ext4_free_encryption_info(struct inode *inode, struct ext4_crypt_info *ci);
-int _ext4_get_encryption_info(struct inode *inode);
+	memset(fname, 0, sizeof(struct ext4_filename));
 
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
-int ext4_has_encryption_key(struct inode *inode);
+	err = fscrypt_setup_filename(dir, iname, lookup, &name);
 
-static inline int ext4_get_encryption_info(struct inode *inode)
-{
-	struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info;
-
-	if (!ci ||
-	    (ci->ci_keyring_key &&
-	     (ci->ci_keyring_key->flags & ((1 << KEY_FLAG_INVALIDATED) |
-					   (1 << KEY_FLAG_REVOKED) |
-					   (1 << KEY_FLAG_DEAD)))))
-		return _ext4_get_encryption_info(inode);
-	return 0;
+	fname->usr_fname = name.usr_fname;
+	fname->disk_name = name.disk_name;
+	fname->hinfo.hash = name.hash;
+	fname->hinfo.minor_hash = name.minor_hash;
+	fname->crypto_buf = name.crypto_buf;
+	return err;
 }
 
-static inline struct ext4_crypt_info *ext4_encryption_info(struct inode *inode)
+static inline void ext4_fname_free_filename(struct ext4_filename *fname)
 {
-	return EXT4_I(inode)->i_crypt_info;
-}
+	struct fscrypt_name name;
 
-#else
-static inline int ext4_has_encryption_key(struct inode *inode)
-{
-	return 0;
+	name.crypto_buf = fname->crypto_buf;
+	fscrypt_free_filename(&name);
+
+	fname->crypto_buf.name = NULL;
+	fname->usr_fname = NULL;
+	fname->disk_name.name = NULL;
 }
-static inline int ext4_get_encryption_info(struct inode *inode)
+#else
+static inline int ext4_fname_setup_filename(struct inode *dir,
+		const struct qstr *iname,
+		int lookup, struct ext4_filename *fname)
 {
+	fname->usr_fname = iname;
+	fname->disk_name.name = (unsigned char *) iname->name;
+	fname->disk_name.len = iname->len;
 	return 0;
 }
-static inline struct ext4_crypt_info *ext4_encryption_info(struct inode *inode)
-{
-	return NULL;
-}
-#endif
+static inline void ext4_fname_free_filename(struct ext4_filename *fname) { }
 
+#define fscrypt_set_d_op(i)
+#define fscrypt_get_ctx			fscrypt_notsupp_get_ctx
+#define fscrypt_release_ctx		fscrypt_notsupp_release_ctx
+#define fscrypt_encrypt_page		fscrypt_notsupp_encrypt_page
+#define fscrypt_decrypt_page		fscrypt_notsupp_decrypt_page
+#define fscrypt_decrypt_bio_pages	fscrypt_notsupp_decrypt_bio_pages
+#define fscrypt_pullback_bio_page	fscrypt_notsupp_pullback_bio_page
+#define fscrypt_restore_control_page	fscrypt_notsupp_restore_control_page
+#define fscrypt_zeroout_range		fscrypt_notsupp_zeroout_range
+#define fscrypt_process_policy		fscrypt_notsupp_process_policy
+#define fscrypt_get_policy		fscrypt_notsupp_get_policy
+#define fscrypt_has_permitted_context	fscrypt_notsupp_has_permitted_context
+#define fscrypt_inherit_context		fscrypt_notsupp_inherit_context
+#define fscrypt_get_encryption_info	fscrypt_notsupp_get_encryption_info
+#define fscrypt_put_encryption_info	fscrypt_notsupp_put_encryption_info
+#define fscrypt_setup_filename		fscrypt_notsupp_setup_filename
+#define fscrypt_free_filename		fscrypt_notsupp_free_filename
+#define fscrypt_fname_encrypted_size	fscrypt_notsupp_fname_encrypted_size
+#define fscrypt_fname_alloc_buffer	fscrypt_notsupp_fname_alloc_buffer
+#define fscrypt_fname_free_buffer	fscrypt_notsupp_fname_free_buffer
+#define fscrypt_fname_disk_to_usr	fscrypt_notsupp_fname_disk_to_usr
+#define fscrypt_fname_usr_to_disk	fscrypt_notsupp_fname_usr_to_disk
+#endif
 
 /* dir.c */
 extern int __ext4_check_dir_entry(const char *, unsigned int, struct inode *,
@@ -2436,7 +2376,7 @@ extern int __ext4_check_dir_entry(const char *, unsigned int, struct inode *,
 extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
 				__u32 minor_hash,
 				struct ext4_dir_entry_2 *dirent,
-				struct ext4_str *ent_name);
+				struct fscrypt_str *ent_name);
 extern void ext4_htree_free_dir_info(struct dir_private_info *p);
 extern int ext4_find_dest_de(struct inode *dir, struct inode *inode,
 			     struct buffer_head *bh,
@@ -2624,7 +2564,7 @@ extern int ext4_generic_delete_entry(handle_t *handle,
 				     void *entry_buf,
 				     int buf_size,
 				     int csum_size);
-extern int ext4_empty_dir(struct inode *inode);
+extern bool ext4_empty_dir(struct inode *inode);
 
 /* resize.c */
 extern int ext4_group_add(struct super_block *sb,
@@ -3106,7 +3046,7 @@ extern int ext4_delete_inline_entry(handle_t *handle,
 				    struct ext4_dir_entry_2 *de_del,
 				    struct buffer_head *bh,
 				    int *has_inline_data);
-extern int empty_inline_dir(struct inode *dir, int *has_inline_data);
+extern bool empty_inline_dir(struct inode *dir, int *has_inline_data);
 extern struct buffer_head *ext4_get_first_inline_block(struct inode *inode,
 					struct ext4_dir_entry_2 **parent_de,
 					int *retval);
diff --git a/fs/ext4/ext4_crypto.h b/fs/ext4/ext4_crypto.h
deleted file mode 100644
index 1f73c29..0000000
--- a/fs/ext4/ext4_crypto.h
+++ /dev/null
@@ -1,159 +0,0 @@
-/*
- * linux/fs/ext4/ext4_crypto.h
- *
- * Copyright (C) 2015, Google, Inc.
- *
- * This contains encryption header content for ext4
- *
- * Written by Michael Halcrow, 2015.
- */
-
-#ifndef _EXT4_CRYPTO_H
-#define _EXT4_CRYPTO_H
-
-#include <linux/fs.h>
-
-#define EXT4_KEY_DESCRIPTOR_SIZE 8
-
-/* Policy provided via an ioctl on the topmost directory */
-struct ext4_encryption_policy {
-	char version;
-	char contents_encryption_mode;
-	char filenames_encryption_mode;
-	char flags;
-	char master_key_descriptor[EXT4_KEY_DESCRIPTOR_SIZE];
-} __attribute__((__packed__));
-
-#define EXT4_ENCRYPTION_CONTEXT_FORMAT_V1 1
-#define EXT4_KEY_DERIVATION_NONCE_SIZE 16
-
-#define EXT4_POLICY_FLAGS_PAD_4		0x00
-#define EXT4_POLICY_FLAGS_PAD_8		0x01
-#define EXT4_POLICY_FLAGS_PAD_16	0x02
-#define EXT4_POLICY_FLAGS_PAD_32	0x03
-#define EXT4_POLICY_FLAGS_PAD_MASK	0x03
-#define EXT4_POLICY_FLAGS_VALID		0x03
-
-/**
- * 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: Reserved
- *  8 bytes: Master Key descriptor
- *  16 bytes: Encryption Key derivation nonce
- */
-struct ext4_encryption_context {
-	char format;
-	char contents_encryption_mode;
-	char filenames_encryption_mode;
-	char flags;
-	char master_key_descriptor[EXT4_KEY_DESCRIPTOR_SIZE];
-	char nonce[EXT4_KEY_DERIVATION_NONCE_SIZE];
-} __attribute__((__packed__));
-
-/* Encryption parameters */
-#define EXT4_XTS_TWEAK_SIZE 16
-#define EXT4_AES_128_ECB_KEY_SIZE 16
-#define EXT4_AES_256_GCM_KEY_SIZE 32
-#define EXT4_AES_256_CBC_KEY_SIZE 32
-#define EXT4_AES_256_CTS_KEY_SIZE 32
-#define EXT4_AES_256_XTS_KEY_SIZE 64
-#define EXT4_MAX_KEY_SIZE 64
-
-#define EXT4_KEY_DESC_PREFIX "ext4:"
-#define EXT4_KEY_DESC_PREFIX_SIZE 5
-
-/* This is passed in from userspace into the kernel keyring */
-struct ext4_encryption_key {
-        __u32 mode;
-        char raw[EXT4_MAX_KEY_SIZE];
-        __u32 size;
-} __attribute__((__packed__));
-
-struct ext4_crypt_info {
-	char		ci_data_mode;
-	char		ci_filename_mode;
-	char		ci_flags;
-	struct crypto_skcipher *ci_ctfm;
-	struct key	*ci_keyring_key;
-	char		ci_master_key[EXT4_KEY_DESCRIPTOR_SIZE];
-};
-
-#define EXT4_CTX_REQUIRES_FREE_ENCRYPT_FL             0x00000001
-#define EXT4_WRITE_PATH_FL			      0x00000002
-
-struct ext4_crypto_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 */
-	};
-	char flags;                      /* Flags */
-	char mode;                       /* Encryption mode for tfm */
-};
-
-struct ext4_completion_result {
-	struct completion completion;
-	int res;
-};
-
-#define DECLARE_EXT4_COMPLETION_RESULT(ecr) \
-	struct ext4_completion_result ecr = { \
-		COMPLETION_INITIALIZER((ecr).completion), 0 }
-
-static inline int ext4_encryption_key_size(int mode)
-{
-	switch (mode) {
-	case EXT4_ENCRYPTION_MODE_AES_256_XTS:
-		return EXT4_AES_256_XTS_KEY_SIZE;
-	case EXT4_ENCRYPTION_MODE_AES_256_GCM:
-		return EXT4_AES_256_GCM_KEY_SIZE;
-	case EXT4_ENCRYPTION_MODE_AES_256_CBC:
-		return EXT4_AES_256_CBC_KEY_SIZE;
-	case EXT4_ENCRYPTION_MODE_AES_256_CTS:
-		return EXT4_AES_256_CTS_KEY_SIZE;
-	default:
-		BUG();
-	}
-	return 0;
-}
-
-#define EXT4_FNAME_NUM_SCATTER_ENTRIES	4
-#define EXT4_CRYPTO_BLOCK_SIZE		16
-#define EXT4_FNAME_CRYPTO_DIGEST_SIZE	32
-
-struct ext4_str {
-	unsigned char *name;
-	u32 len;
-};
-
-/**
- * For encrypted symlinks, the ciphertext length is stored at the beginning
- * of the string in little-endian format.
- */
-struct ext4_encrypted_symlink_data {
-	__le16 len;
-	char encrypted_path[1];
-} __attribute__((__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 encrypted_symlink_data_len(u32 l)
-{
-	if (l < EXT4_CRYPTO_BLOCK_SIZE)
-		l = EXT4_CRYPTO_BLOCK_SIZE;
-	return (l + sizeof(struct ext4_encrypted_symlink_data) - 1);
-}
-
-#endif	/* _EXT4_CRYPTO_H */
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index df44c87..4f615cd 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -303,10 +303,10 @@ static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma)
 	struct inode *inode = file->f_mapping->host;
 
 	if (ext4_encrypted_inode(inode)) {
-		int err = ext4_get_encryption_info(inode);
+		int err = fscrypt_get_encryption_info(inode);
 		if (err)
 			return 0;
-		if (ext4_encryption_info(inode) == NULL)
+		if (!fscrypt_has_encryption_key(inode))
 			return -ENOKEY;
 	}
 	file_accessed(file);
@@ -362,16 +362,16 @@ static int ext4_file_open(struct inode * inode, struct file * filp)
 		}
 	}
 	if (ext4_encrypted_inode(inode)) {
-		ret = ext4_get_encryption_info(inode);
+		ret = fscrypt_get_encryption_info(inode);
 		if (ret)
 			return -EACCES;
-		if (ext4_encryption_info(inode) == NULL)
+		if (!fscrypt_has_encryption_key(inode))
 			return -ENOKEY;
 	}
 
 	dir = dget_parent(file_dentry(filp));
 	if (ext4_encrypted_inode(d_inode(dir)) &&
-	    !ext4_is_child_context_consistent_with_parent(d_inode(dir), inode)) {
+			!fscrypt_has_permitted_context(d_inode(dir), inode)) {
 		ext4_warning(inode->i_sb,
 			     "Inconsistent encryption contexts: %lu/%lu",
 			     (unsigned long) d_inode(dir)->i_ino,
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index 3da4cf8..35f3518 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -767,10 +767,10 @@ struct inode *__ext4_new_inode(handle_t *handle, struct inode *dir,
 	if ((ext4_encrypted_inode(dir) ||
 	     DUMMY_ENCRYPTION_ENABLED(EXT4_SB(dir->i_sb))) &&
 	    (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
-		err = ext4_get_encryption_info(dir);
+		err = fscrypt_get_encryption_info(dir);
 		if (err)
 			return ERR_PTR(err);
-		if (ext4_encryption_info(dir) == NULL)
+		if (!fscrypt_has_encryption_key(dir))
 			return ERR_PTR(-EPERM);
 		if (!handle)
 			nblocks += EXT4_DATA_TRANS_BLOCKS(dir->i_sb);
@@ -1115,7 +1115,8 @@ got:
 	}
 
 	if (encrypt) {
-		err = ext4_inherit_context(dir, inode);
+		/* give pointer to avoid set_context with journal ops. */
+		err = fscrypt_inherit_context(dir, inode, &encrypt, true);
 		if (err)
 			goto fail_free_drop;
 	}
diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
index ff7538c..f74d5ee 100644
--- a/fs/ext4/inline.c
+++ b/fs/ext4/inline.c
@@ -1326,7 +1326,7 @@ int htree_inlinedir_to_tree(struct file *dir_file,
 	struct ext4_iloc iloc;
 	void *dir_buf = NULL;
 	struct ext4_dir_entry_2 fake;
-	struct ext4_str tmp_str;
+	struct fscrypt_str tmp_str;
 
 	ret = ext4_get_inode_loc(inode, &iloc);
 	if (ret)
@@ -1739,20 +1739,20 @@ ext4_get_inline_entry(struct inode *inode,
 	return (struct ext4_dir_entry_2 *)(inline_pos + offset);
 }
 
-int empty_inline_dir(struct inode *dir, int *has_inline_data)
+bool empty_inline_dir(struct inode *dir, int *has_inline_data)
 {
 	int err, inline_size;
 	struct ext4_iloc iloc;
 	void *inline_pos;
 	unsigned int offset;
 	struct ext4_dir_entry_2 *de;
-	int ret = 1;
+	bool ret = true;
 
 	err = ext4_get_inode_loc(dir, &iloc);
 	if (err) {
 		EXT4_ERROR_INODE(dir, "error %d getting inode %lu block",
 				 err, dir->i_ino);
-		return 1;
+		return true;
 	}
 
 	down_read(&EXT4_I(dir)->xattr_sem);
@@ -1766,7 +1766,7 @@ int empty_inline_dir(struct inode *dir, int *has_inline_data)
 		ext4_warning(dir->i_sb,
 			     "bad inline directory (dir #%lu) - no `..'",
 			     dir->i_ino);
-		ret = 1;
+		ret = true;
 		goto out;
 	}
 
@@ -1784,11 +1784,11 @@ int empty_inline_dir(struct inode *dir, int *has_inline_data)
 				     dir->i_ino, le32_to_cpu(de->inode),
 				     le16_to_cpu(de->rec_len), de->name_len,
 				     inline_size);
-			ret = 1;
+			ret = true;
 			goto out;
 		}
 		if (le32_to_cpu(de->inode)) {
-			ret = 0;
+			ret = false;
 			goto out;
 		}
 		offset += ext4_rec_len_from_disk(de->rec_len, inline_size);
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index ea39d19..5a6277d 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -392,7 +392,7 @@ int ext4_issue_zeroout(struct inode *inode, ext4_lblk_t lblk, ext4_fsblk_t pblk,
 	int ret;
 
 	if (ext4_encrypted_inode(inode))
-		return ext4_encrypted_zeroout(inode, lblk, pblk, len);
+		return fscrypt_zeroout_range(inode, lblk, pblk, len);
 
 	ret = sb_issue_zeroout(inode->i_sb, pblk, len, GFP_NOFS);
 	if (ret > 0)
@@ -1158,7 +1158,7 @@ static int ext4_block_write_begin(struct page *page, loff_t pos, unsigned len,
 	if (unlikely(err))
 		page_zero_new_buffers(page, from, to);
 	else if (decrypt)
-		err = ext4_decrypt(page);
+		err = fscrypt_decrypt_page(page);
 	return err;
 }
 #endif
@@ -3735,9 +3735,9 @@ static int __ext4_block_zero_page_range(handle_t *handle,
 		if (S_ISREG(inode->i_mode) &&
 		    ext4_encrypted_inode(inode)) {
 			/* We expect the key to be set. */
-			BUG_ON(!ext4_has_encryption_key(inode));
+			BUG_ON(!fscrypt_has_encryption_key(inode));
 			BUG_ON(blocksize != PAGE_SIZE);
-			WARN_ON_ONCE(ext4_decrypt(page));
+			WARN_ON_ONCE(fscrypt_decrypt_page(page));
 		}
 	}
 	if (ext4_should_journal_data(inode)) {
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index b5a39b0..10686fd 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -770,19 +770,13 @@ resizefs_out:
 		return ext4_ext_precache(inode);
 	case EXT4_IOC_SET_ENCRYPTION_POLICY: {
 #ifdef CONFIG_EXT4_FS_ENCRYPTION
-		struct ext4_encryption_policy policy;
-		int err = 0;
+		struct fscrypt_policy policy;
 
 		if (copy_from_user(&policy,
-				   (struct ext4_encryption_policy __user *)arg,
-				   sizeof(policy))) {
-			err = -EFAULT;
-			goto encryption_policy_out;
-		}
-
-		err = ext4_process_policy(&policy, inode);
-encryption_policy_out:
-		return err;
+				   (struct fscrypt_policy __user *)arg,
+				   sizeof(policy)))
+			return -EFAULT;
+		return fscrypt_process_policy(inode, &policy);
 #else
 		return -EOPNOTSUPP;
 #endif
@@ -825,12 +819,12 @@ encryption_policy_out:
 	}
 	case EXT4_IOC_GET_ENCRYPTION_POLICY: {
 #ifdef CONFIG_EXT4_FS_ENCRYPTION
-		struct ext4_encryption_policy policy;
+		struct fscrypt_policy policy;
 		int err = 0;
 
 		if (!ext4_encrypted_inode(inode))
 			return -ENOENT;
-		err = ext4_get_policy(inode, &policy);
+		err = fscrypt_get_policy(inode, &policy);
 		if (err)
 			return err;
 		if (copy_to_user((void __user *)arg, &policy, sizeof(policy)))
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 94d22e7..4637c43 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -611,19 +611,19 @@ static struct stats dx_show_leaf(struct inode *dir,
 #ifdef CONFIG_EXT4_FS_ENCRYPTION
 				int len;
 				char *name;
-				struct ext4_str fname_crypto_str
-					= {.name = NULL, .len = 0};
+				struct fscrypt_str fname_crypto_str =
+					FSTR_INIT(NULL, 0);
 				int res = 0;
 
 				name  = de->name;
 				len = de->name_len;
-				if (ext4_encrypted_inode(inode))
-					res = ext4_get_encryption_info(dir);
+				if (ext4_encrypted_inode(dir))
+					res = fscrypt_get_encryption_info(dir);
 				if (res) {
 					printk(KERN_WARNING "Error setting up"
 					       " fname crypto: %d\n", res);
 				}
-				if (ctx == NULL) {
+				if (!fscrypt_has_encryption_key(dir)) {
 					/* Directory is not encrypted */
 					ext4fs_dirhash(de->name,
 						de->name_len, &h);
@@ -632,19 +632,21 @@ static struct stats dx_show_leaf(struct inode *dir,
 					       (unsigned) ((char *) de
 							   - base));
 				} else {
+					struct fscrypt_str de_name =
+						FSTR_INIT(name, len);
+
 					/* Directory is encrypted */
-					res = ext4_fname_crypto_alloc_buffer(
-						ctx, de->name_len,
+					res = fscrypt_fname_alloc_buffer(
+						dir, len,
 						&fname_crypto_str);
-					if (res < 0) {
+					if (res < 0)
 						printk(KERN_WARNING "Error "
 							"allocating crypto "
 							"buffer--skipping "
 							"crypto\n");
-						ctx = NULL;
-					}
-					res = ext4_fname_disk_to_usr(ctx, NULL, de,
-							&fname_crypto_str);
+					res = fscrypt_fname_disk_to_usr(dir,
+						0, 0, &de_name,
+						&fname_crypto_str);
 					if (res < 0) {
 						printk(KERN_WARNING "Error "
 							"converting filename "
@@ -661,8 +663,8 @@ static struct stats dx_show_leaf(struct inode *dir,
 					printk("%*.s:(E)%x.%u ", len, name,
 					       h.hash, (unsigned) ((char *) de
 								   - base));
-					ext4_fname_crypto_free_buffer(
-						&fname_crypto_str);
+					fscrypt_fname_free_buffer(
+							&fname_crypto_str);
 				}
 #else
 				int len = de->name_len;
@@ -951,7 +953,7 @@ static int htree_dirblock_to_tree(struct file *dir_file,
 	struct buffer_head *bh;
 	struct ext4_dir_entry_2 *de, *top;
 	int err = 0, count = 0;
-	struct ext4_str fname_crypto_str = {.name = NULL, .len = 0}, tmp_str;
+	struct fscrypt_str fname_crypto_str = FSTR_INIT(NULL, 0), tmp_str;
 
 	dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
 							(unsigned long)block));
@@ -966,12 +968,12 @@ static int htree_dirblock_to_tree(struct file *dir_file,
 #ifdef CONFIG_EXT4_FS_ENCRYPTION
 	/* Check if the directory is encrypted */
 	if (ext4_encrypted_inode(dir)) {
-		err = ext4_get_encryption_info(dir);
+		err = fscrypt_get_encryption_info(dir);
 		if (err < 0) {
 			brelse(bh);
 			return err;
 		}
-		err = ext4_fname_crypto_alloc_buffer(dir, EXT4_NAME_LEN,
+		err = fscrypt_fname_alloc_buffer(dir, EXT4_NAME_LEN,
 						     &fname_crypto_str);
 		if (err < 0) {
 			brelse(bh);
@@ -1002,10 +1004,13 @@ static int htree_dirblock_to_tree(struct file *dir_file,
 				   &tmp_str);
 		} else {
 			int save_len = fname_crypto_str.len;
+			struct fscrypt_str de_name = FSTR_INIT(de->name,
+								de->name_len);
 
 			/* Directory is encrypted */
-			err = ext4_fname_disk_to_usr(dir, hinfo, de,
-						     &fname_crypto_str);
+			err = fscrypt_fname_disk_to_usr(dir, hinfo->hash,
+					hinfo->minor_hash, &de_name,
+					&fname_crypto_str);
 			if (err < 0) {
 				count = err;
 				goto errout;
@@ -1024,7 +1029,7 @@ static int htree_dirblock_to_tree(struct file *dir_file,
 errout:
 	brelse(bh);
 #ifdef CONFIG_EXT4_FS_ENCRYPTION
-	ext4_fname_crypto_free_buffer(&fname_crypto_str);
+	fscrypt_fname_free_buffer(&fname_crypto_str);
 #endif
 	return count;
 }
@@ -1049,7 +1054,7 @@ int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
 	int count = 0;
 	int ret, err;
 	__u32 hashval;
-	struct ext4_str tmp_str;
+	struct fscrypt_str tmp_str;
 
 	dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
 		       start_hash, start_minor_hash));
@@ -1562,26 +1567,23 @@ static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsi
 	struct ext4_dir_entry_2 *de;
 	struct buffer_head *bh;
 
-       if (ext4_encrypted_inode(dir)) {
-               int res = ext4_get_encryption_info(dir);
+	if (ext4_encrypted_inode(dir)) {
+		int res = fscrypt_get_encryption_info(dir);
 
 		/*
-		 * This should be a properly defined flag for
-		 * dentry->d_flags when we uplift this to the VFS.
-		 * d_fsdata is set to (void *) 1 if if the dentry is
+		 * DCACHE_ENCRYPTED_WITH_KEY is set if the dentry is
 		 * created while the directory was encrypted and we
-		 * don't have access to the key.
+		 * have access to the key.
 		 */
-	       dentry->d_fsdata = NULL;
-	       if (ext4_encryption_info(dir))
-		       dentry->d_fsdata = (void *) 1;
-	       d_set_d_op(dentry, &ext4_encrypted_d_ops);
-	       if (res && res != -ENOKEY)
-		       return ERR_PTR(res);
-       }
+		if (fscrypt_has_encryption_key(dir))
+			fscrypt_set_encrypted_dentry(dentry);
+		fscrypt_set_d_op(dentry);
+		if (res && res != -ENOKEY)
+			return ERR_PTR(res);
+	}
 
-	if (dentry->d_name.len > EXT4_NAME_LEN)
-		return ERR_PTR(-ENAMETOOLONG);
+       if (dentry->d_name.len > EXT4_NAME_LEN)
+	       return ERR_PTR(-ENAMETOOLONG);
 
 	bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
 	if (IS_ERR(bh))
@@ -1608,11 +1610,9 @@ static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsi
 		}
 		if (!IS_ERR(inode) && ext4_encrypted_inode(dir) &&
 		    (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) &&
-		    !ext4_is_child_context_consistent_with_parent(dir,
-								  inode)) {
+		    !fscrypt_has_permitted_context(dir, inode)) {
 			int nokey = ext4_encrypted_inode(inode) &&
-				!ext4_encryption_info(inode);
-
+				!fscrypt_has_encryption_key(inode);
 			iput(inode);
 			if (nokey)
 				return ERR_PTR(-ENOKEY);
@@ -2689,30 +2689,30 @@ out_stop:
 /*
  * routine to check that the specified directory is empty (for rmdir)
  */
-int ext4_empty_dir(struct inode *inode)
+bool ext4_empty_dir(struct inode *inode)
 {
 	unsigned int offset;
 	struct buffer_head *bh;
 	struct ext4_dir_entry_2 *de, *de1;
 	struct super_block *sb;
-	int err = 0;
 
 	if (ext4_has_inline_data(inode)) {
 		int has_inline_data = 1;
+		int ret;
 
-		err = empty_inline_dir(inode, &has_inline_data);
+		ret = empty_inline_dir(inode, &has_inline_data);
 		if (has_inline_data)
-			return err;
+			return ret;
 	}
 
 	sb = inode->i_sb;
 	if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)) {
 		EXT4_ERROR_INODE(inode, "invalid size");
-		return 1;
+		return true;
 	}
 	bh = ext4_read_dirblock(inode, 0, EITHER);
 	if (IS_ERR(bh))
-		return 1;
+		return true;
 
 	de = (struct ext4_dir_entry_2 *) bh->b_data;
 	de1 = ext4_next_entry(de, sb->s_blocksize);
@@ -2721,7 +2721,7 @@ int ext4_empty_dir(struct inode *inode)
 			strcmp(".", de->name) || strcmp("..", de1->name)) {
 		ext4_warning_inode(inode, "directory missing '.' and/or '..'");
 		brelse(bh);
-		return 1;
+		return true;
 	}
 	offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
 		 ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
@@ -2729,12 +2729,11 @@ int ext4_empty_dir(struct inode *inode)
 	while (offset < inode->i_size) {
 		if ((void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
 			unsigned int lblock;
-			err = 0;
 			brelse(bh);
 			lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
 			bh = ext4_read_dirblock(inode, lblock, EITHER);
 			if (IS_ERR(bh))
-				return 1;
+				return true;
 			de = (struct ext4_dir_entry_2 *) bh->b_data;
 		}
 		if (ext4_check_dir_entry(inode, NULL, de, bh,
@@ -2746,13 +2745,13 @@ int ext4_empty_dir(struct inode *inode)
 		}
 		if (le32_to_cpu(de->inode)) {
 			brelse(bh);
-			return 0;
+			return false;
 		}
 		offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
 		de = ext4_next_entry(de, sb->s_blocksize);
 	}
 	brelse(bh);
-	return 1;
+	return true;
 }
 
 /*
@@ -3075,8 +3074,8 @@ static int ext4_symlink(struct inode *dir,
 	int err, len = strlen(symname);
 	int credits;
 	bool encryption_required;
-	struct ext4_str disk_link;
-	struct ext4_encrypted_symlink_data *sd = NULL;
+	struct fscrypt_str disk_link;
+	struct fscrypt_symlink_data *sd = NULL;
 
 	disk_link.len = len + 1;
 	disk_link.name = (char *) symname;
@@ -3084,13 +3083,13 @@ static int ext4_symlink(struct inode *dir,
 	encryption_required = (ext4_encrypted_inode(dir) ||
 			       DUMMY_ENCRYPTION_ENABLED(EXT4_SB(dir->i_sb)));
 	if (encryption_required) {
-		err = ext4_get_encryption_info(dir);
+		err = fscrypt_get_encryption_info(dir);
 		if (err)
 			return err;
-		if (ext4_encryption_info(dir) == NULL)
+		if (!fscrypt_has_encryption_key(dir))
 			return -EPERM;
-		disk_link.len = (ext4_fname_encrypted_size(dir, len) +
-				 sizeof(struct ext4_encrypted_symlink_data));
+		disk_link.len = (fscrypt_fname_encrypted_size(dir, len) +
+				 sizeof(struct fscrypt_symlink_data));
 		sd = kzalloc(disk_link.len, GFP_KERNEL);
 		if (!sd)
 			return -ENOMEM;
@@ -3138,13 +3137,12 @@ static int ext4_symlink(struct inode *dir,
 
 	if (encryption_required) {
 		struct qstr istr;
-		struct ext4_str ostr;
+		struct fscrypt_str ostr =
+			FSTR_INIT(sd->encrypted_path, disk_link.len);
 
 		istr.name = (const unsigned char *) symname;
 		istr.len = len;
-		ostr.name = sd->encrypted_path;
-		ostr.len = disk_link.len;
-		err = ext4_fname_usr_to_disk(inode, &istr, &ostr);
+		err = fscrypt_fname_usr_to_disk(inode, &istr, &ostr);
 		if (err < 0)
 			goto err_drop_inode;
 		sd->len = cpu_to_le16(ostr.len);
@@ -3233,7 +3231,7 @@ static int ext4_link(struct dentry *old_dentry,
 	if (inode->i_nlink >= EXT4_LINK_MAX)
 		return -EMLINK;
 	if (ext4_encrypted_inode(dir) &&
-	    !ext4_is_child_context_consistent_with_parent(dir, inode))
+			!fscrypt_has_permitted_context(dir, inode))
 		return -EPERM;
 
        if ((ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT)) &&
@@ -3556,8 +3554,7 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
 
 	if ((old.dir != new.dir) &&
 	    ext4_encrypted_inode(new.dir) &&
-	    !ext4_is_child_context_consistent_with_parent(new.dir,
-							  old.inode)) {
+	    !fscrypt_has_permitted_context(new.dir, old.inode)) {
 		retval = -EPERM;
 		goto end_rename;
 	}
@@ -3729,10 +3726,8 @@ static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
 	if ((ext4_encrypted_inode(old_dir) ||
 	     ext4_encrypted_inode(new_dir)) &&
 	    (old_dir != new_dir) &&
-	    (!ext4_is_child_context_consistent_with_parent(new_dir,
-							   old.inode) ||
-	     !ext4_is_child_context_consistent_with_parent(old_dir,
-							   new.inode)))
+	    (!fscrypt_has_permitted_context(new_dir, old.inode) ||
+	     !fscrypt_has_permitted_context(old_dir, new.inode)))
 		return -EPERM;
 
 	if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT) &&
diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c
index 2a01df9..5ad05af 100644
--- a/fs/ext4/page-io.c
+++ b/fs/ext4/page-io.c
@@ -24,6 +24,7 @@
 #include <linux/slab.h>
 #include <linux/mm.h>
 #include <linux/backing-dev.h>
+#include <linux/fscrypto.h>
 
 #include "ext4_jbd2.h"
 #include "xattr.h"
@@ -67,7 +68,6 @@ static void ext4_finish_bio(struct bio *bio)
 		struct page *page = bvec->bv_page;
 #ifdef CONFIG_EXT4_FS_ENCRYPTION
 		struct page *data_page = NULL;
-		struct ext4_crypto_ctx *ctx = NULL;
 #endif
 		struct buffer_head *bh, *head;
 		unsigned bio_start = bvec->bv_offset;
@@ -82,8 +82,7 @@ static void ext4_finish_bio(struct bio *bio)
 		if (!page->mapping) {
 			/* The bounce data pages are unmapped. */
 			data_page = page;
-			ctx = (struct ext4_crypto_ctx *)page_private(data_page);
-			page = ctx->w.control_page;
+			fscrypt_pullback_bio_page(&page, false);
 		}
 #endif
 
@@ -113,8 +112,8 @@ static void ext4_finish_bio(struct bio *bio)
 		local_irq_restore(flags);
 		if (!under_io) {
 #ifdef CONFIG_EXT4_FS_ENCRYPTION
-			if (ctx)
-				ext4_restore_control_page(data_page);
+			if (data_page)
+				fscrypt_restore_control_page(data_page);
 #endif
 			end_page_writeback(page);
 		}
@@ -472,7 +471,7 @@ int ext4_bio_write_page(struct ext4_io_submit *io,
 		gfp_t gfp_flags = GFP_NOFS;
 
 	retry_encrypt:
-		data_page = ext4_encrypt(inode, page, gfp_flags);
+		data_page = fscrypt_encrypt_page(inode, page, gfp_flags);
 		if (IS_ERR(data_page)) {
 			ret = PTR_ERR(data_page);
 			if (ret == -ENOMEM && wbc->sync_mode == WB_SYNC_ALL) {
@@ -510,7 +509,7 @@ int ext4_bio_write_page(struct ext4_io_submit *io,
 	if (ret) {
 	out:
 		if (data_page)
-			ext4_restore_control_page(data_page);
+			fscrypt_restore_control_page(data_page);
 		printk_ratelimited(KERN_ERR "%s: ret = %d\n", __func__, ret);
 		redirty_page_for_writepage(wbc, page);
 		do {
diff --git a/fs/ext4/readpage.c b/fs/ext4/readpage.c
index e24ec3b..18b2cf2 100644
--- a/fs/ext4/readpage.c
+++ b/fs/ext4/readpage.c
@@ -46,37 +46,6 @@
 
 #include "ext4.h"
 
-/*
- * Call ext4_decrypt on every single page, reusing the encryption
- * context.
- */
-static void completion_pages(struct work_struct *work)
-{
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
-	struct ext4_crypto_ctx *ctx =
-		container_of(work, struct ext4_crypto_ctx, r.work);
-	struct bio	*bio	= ctx->r.bio;
-	struct bio_vec	*bv;
-	int		i;
-
-	bio_for_each_segment_all(bv, bio, i) {
-		struct page *page = bv->bv_page;
-
-		int ret = ext4_decrypt(page);
-		if (ret) {
-			WARN_ON_ONCE(1);
-			SetPageError(page);
-		} else
-			SetPageUptodate(page);
-		unlock_page(page);
-	}
-	ext4_release_crypto_ctx(ctx);
-	bio_put(bio);
-#else
-	BUG();
-#endif
-}
-
 static inline bool ext4_bio_encrypted(struct bio *bio)
 {
 #ifdef CONFIG_EXT4_FS_ENCRYPTION
@@ -104,14 +73,10 @@ static void mpage_end_io(struct bio *bio)
 	int i;
 
 	if (ext4_bio_encrypted(bio)) {
-		struct ext4_crypto_ctx *ctx = bio->bi_private;
-
 		if (bio->bi_error) {
-			ext4_release_crypto_ctx(ctx);
+			fscrypt_release_ctx(bio->bi_private);
 		} else {
-			INIT_WORK(&ctx->r.work, completion_pages);
-			ctx->r.bio = bio;
-			queue_work(ext4_read_workqueue, &ctx->r.work);
+			fscrypt_decrypt_bio_pages(bio->bi_private, bio);
 			return;
 		}
 	}
@@ -274,11 +239,11 @@ int ext4_mpage_readpages(struct address_space *mapping,
 			bio = NULL;
 		}
 		if (bio == NULL) {
-			struct ext4_crypto_ctx *ctx = NULL;
+			struct fscrypt_ctx *ctx = NULL;
 
 			if (ext4_encrypted_inode(inode) &&
 			    S_ISREG(inode->i_mode)) {
-				ctx = ext4_get_crypto_ctx(inode, GFP_NOFS);
+				ctx = fscrypt_get_ctx(inode, GFP_NOFS);
 				if (IS_ERR(ctx))
 					goto set_error_page;
 			}
@@ -286,7 +251,7 @@ int ext4_mpage_readpages(struct address_space *mapping,
 				min_t(int, nr_pages, BIO_MAX_PAGES));
 			if (!bio) {
 				if (ctx)
-					ext4_release_crypto_ctx(ctx);
+					fscrypt_release_ctx(ctx);
 				goto set_error_page;
 			}
 			bio->bi_bdev = bdev;
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 13c49af7..1e3fd5c 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -945,9 +945,6 @@ static struct inode *ext4_alloc_inode(struct super_block *sb)
 	ei->i_datasync_tid = 0;
 	atomic_set(&ei->i_unwritten, 0);
 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
-	ei->i_crypt_info = NULL;
-#endif
 	return &ei->vfs_inode;
 }
 
@@ -1026,8 +1023,7 @@ void ext4_clear_inode(struct inode *inode)
 		EXT4_I(inode)->jinode = NULL;
 	}
 #ifdef CONFIG_EXT4_FS_ENCRYPTION
-	if (EXT4_I(inode)->i_crypt_info)
-		ext4_free_encryption_info(inode, EXT4_I(inode)->i_crypt_info);
+	fscrypt_put_encryption_info(inode, NULL);
 #endif
 }
 
@@ -1094,6 +1090,90 @@ static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
 	return try_to_free_buffers(page);
 }
 
+#ifdef CONFIG_EXT4_FS_ENCRYPTION
+static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
+{
+	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
+				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
+}
+
+static int ext4_key_prefix(struct inode *inode, u8 **key)
+{
+	*key = EXT4_SB(inode->i_sb)->key_prefix;
+	return EXT4_SB(inode->i_sb)->key_prefix_size;
+}
+
+static int ext4_prepare_context(struct inode *inode)
+{
+	return ext4_convert_inline_data(inode);
+}
+
+static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
+							void *fs_data)
+{
+	handle_t *handle;
+	int res, res2;
+
+	/* fs_data is null when internally used. */
+	if (fs_data) {
+		res  = ext4_xattr_set(inode, EXT4_XATTR_INDEX_ENCRYPTION,
+				EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx,
+				len, 0);
+		if (!res) {
+			ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
+			ext4_clear_inode_state(inode,
+					EXT4_STATE_MAY_INLINE_DATA);
+		}
+		return res;
+	}
+
+	handle = ext4_journal_start(inode, EXT4_HT_MISC,
+			ext4_jbd2_credits_xattr(inode));
+	if (IS_ERR(handle))
+		return PTR_ERR(handle);
+
+	res = ext4_xattr_set(inode, EXT4_XATTR_INDEX_ENCRYPTION,
+			EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx,
+			len, 0);
+	if (!res) {
+		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
+		res = ext4_mark_inode_dirty(handle, inode);
+		if (res)
+			EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
+	}
+	res2 = ext4_journal_stop(handle);
+	if (!res)
+		res = res2;
+	return res;
+}
+
+static int ext4_dummy_context(struct inode *inode)
+{
+	return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
+}
+
+static unsigned ext4_max_namelen(struct inode *inode)
+{
+	return S_ISLNK(inode->i_mode) ? inode->i_sb->s_blocksize :
+		EXT4_NAME_LEN;
+}
+
+static struct fscrypt_operations ext4_cryptops = {
+	.get_context		= ext4_get_context,
+	.key_prefix		= ext4_key_prefix,
+	.prepare_context	= ext4_prepare_context,
+	.set_context		= ext4_set_context,
+	.dummy_context		= ext4_dummy_context,
+	.is_encrypted		= ext4_encrypted_inode,
+	.empty_dir		= ext4_empty_dir,
+	.max_namelen		= ext4_max_namelen,
+};
+#else
+static struct fscrypt_operations ext4_cryptops = {
+	.is_encrypted		= ext4_encrypted_inode,
+};
+#endif
+
 #ifdef CONFIG_QUOTA
 static char *quotatypes[] = INITQFNAMES;
 #define QTYPE2NAME(t) (quotatypes[t])
@@ -3693,6 +3773,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 	sb->s_op = &ext4_sops;
 	sb->s_export_op = &ext4_export_ops;
 	sb->s_xattr = ext4_xattr_handlers;
+	sb->s_cop = &ext4_cryptops;
 #ifdef CONFIG_QUOTA
 	sb->dq_op = &ext4_quota_operations;
 	if (ext4_has_feature_quota(sb))
@@ -4003,6 +4084,11 @@ no_journal:
 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
 
 	kfree(orig_data);
+#ifdef CONFIG_EXT4_FS_ENCRYPTION
+	memcpy(sbi->key_prefix, EXT4_KEY_DESC_PREFIX,
+				EXT4_KEY_DESC_PREFIX_SIZE);
+	sbi->key_prefix_size = EXT4_KEY_DESC_PREFIX_SIZE;
+#endif
 	return 0;
 
 cantfind_ext4:
@@ -5431,7 +5517,6 @@ out5:
 
 static void __exit ext4_exit_fs(void)
 {
-	ext4_exit_crypto();
 	ext4_destroy_lazyinit_thread();
 	unregister_as_ext2();
 	unregister_as_ext3();
diff --git a/fs/ext4/symlink.c b/fs/ext4/symlink.c
index 75ed5c2..4d83d9e 100644
--- a/fs/ext4/symlink.c
+++ b/fs/ext4/symlink.c
@@ -22,23 +22,22 @@
 #include "ext4.h"
 #include "xattr.h"
 
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
 static const char *ext4_encrypted_get_link(struct dentry *dentry,
 					   struct inode *inode,
 					   struct delayed_call *done)
 {
 	struct page *cpage = NULL;
 	char *caddr, *paddr = NULL;
-	struct ext4_str cstr, pstr;
-	struct ext4_encrypted_symlink_data *sd;
+	struct fscrypt_str cstr, pstr;
+	struct fscrypt_symlink_data *sd;
 	loff_t size = min_t(loff_t, i_size_read(inode), PAGE_SIZE - 1);
 	int res;
-	u32 plen, max_size = inode->i_sb->s_blocksize;
+	u32 max_size = inode->i_sb->s_blocksize;
 
 	if (!dentry)
 		return ERR_PTR(-ECHILD);
 
-	res = ext4_get_encryption_info(inode);
+	res = fscrypt_get_encryption_info(inode);
 	if (res)
 		return ERR_PTR(res);
 
@@ -54,30 +53,27 @@ static const char *ext4_encrypted_get_link(struct dentry *dentry,
 	}
 
 	/* Symlink is encrypted */
-	sd = (struct ext4_encrypted_symlink_data *)caddr;
+	sd = (struct fscrypt_symlink_data *)caddr;
 	cstr.name = sd->encrypted_path;
 	cstr.len  = le16_to_cpu(sd->len);
-	if ((cstr.len +
-	     sizeof(struct ext4_encrypted_symlink_data) - 1) >
-	    max_size) {
+	if ((cstr.len + sizeof(struct fscrypt_symlink_data) - 1) > max_size) {
 		/* Symlink data on the disk is corrupted */
 		res = -EFSCORRUPTED;
 		goto errout;
 	}
-	plen = (cstr.len < EXT4_FNAME_CRYPTO_DIGEST_SIZE*2) ?
-		EXT4_FNAME_CRYPTO_DIGEST_SIZE*2 : cstr.len;
-	paddr = kmalloc(plen + 1, GFP_NOFS);
-	if (!paddr) {
-		res = -ENOMEM;
+
+	res = fscrypt_fname_alloc_buffer(inode, cstr.len, &pstr);
+	if (res)
 		goto errout;
-	}
-	pstr.name = paddr;
-	pstr.len = plen;
-	res = _ext4_fname_disk_to_usr(inode, NULL, &cstr, &pstr);
+
+	res = fscrypt_fname_disk_to_usr(inode, 0, 0, &cstr, &pstr);
 	if (res < 0)
 		goto errout;
+
+	paddr = pstr.name;
+
 	/* Null-terminate the name */
-	if (res <= plen)
+	if (res <= pstr.len)
 		paddr[res] = '\0';
 	if (cpage)
 		put_page(cpage);
@@ -99,7 +95,6 @@ const struct inode_operations ext4_encrypted_symlink_inode_operations = {
 	.listxattr	= ext4_listxattr,
 	.removexattr	= generic_removexattr,
 };
-#endif
 
 const struct inode_operations ext4_symlink_inode_operations = {
 	.readlink	= generic_readlink,