[RFC PATCH 1/1] btrfs: Encryption: Add btrfs encryption support

[Anand Jain <anand.jain@oracle.com>]

***
*** Warning: Experimental code.
***

Adds encryption support. The branch is based on v4.5-rc6.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
---
 fs/btrfs/Makefile      |   2 +-
 fs/btrfs/btrfs_inode.h |   2 +
 fs/btrfs/compression.c |  53 ++++-
 fs/btrfs/compression.h |   1 +
 fs/btrfs/ctree.h       |  11 +-
 fs/btrfs/encrypt.c     | 544 +++++++++++++++++++++++++++++++++++++++++++++++++
 fs/btrfs/encrypt.h     |  21 ++
 fs/btrfs/inode.c       |  37 +++-
 fs/btrfs/ioctl.c       |   7 +
 fs/btrfs/props.c       | 140 ++++++++++++-
 fs/btrfs/super.c       |   5 +-
 11 files changed, 812 insertions(+), 11 deletions(-)
 create mode 100644 fs/btrfs/encrypt.c
 create mode 100644 fs/btrfs/encrypt.h

diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile
index 128ce17a80b0..2765778c5898 100644
--- a/fs/btrfs/Makefile
+++ b/fs/btrfs/Makefile
@@ -9,7 +9,7 @@ btrfs-y += super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \
 	   export.o tree-log.o free-space-cache.o zlib.o lzo.o \
 	   compression.o delayed-ref.o relocation.o delayed-inode.o scrub.o \
 	   reada.o backref.o ulist.o qgroup.o send.o dev-replace.o raid56.o \
-	   uuid-tree.o props.o hash.o free-space-tree.o
+	   uuid-tree.o props.o hash.o free-space-tree.o encrypt.o
 
 btrfs-$(CONFIG_BTRFS_FS_POSIX_ACL) += acl.o
 btrfs-$(CONFIG_BTRFS_FS_CHECK_INTEGRITY) += check-integrity.o
diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
index 61205e3bbefa..4f09572b4922 100644
--- a/fs/btrfs/btrfs_inode.h
+++ b/fs/btrfs/btrfs_inode.h
@@ -197,6 +197,8 @@ struct btrfs_inode {
 	long delayed_iput_count;
 
 	struct inode vfs_inode;
+
+	unsigned char key_payload[16];
 };
 
 extern unsigned char btrfs_filetype_table[];
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 3346cd8f9910..d59c366f4200 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -41,6 +41,7 @@
 #include "compression.h"
 #include "extent_io.h"
 #include "extent_map.h"
+#include "encrypt.h"
 
 struct compressed_bio {
 	/* number of bios pending for this compressed extent */
@@ -182,7 +183,7 @@ static void end_compressed_bio_read(struct bio *bio)
 				      cb->orig_bio->bi_vcnt,
 				      cb->compressed_len);
 csum_failed:
-	if (ret)
+	if (ret && ret != -ENOKEY)
 		cb->errors = 1;
 
 	/* release the compressed pages */
@@ -751,6 +752,7 @@ static struct {
 static const struct btrfs_compress_op * const btrfs_compress_op[] = {
 	&btrfs_zlib_compress,
 	&btrfs_lzo_compress,
+	&btrfs_encrypt_ops,
 };
 
 void __init btrfs_init_compress(void)
@@ -780,6 +782,10 @@ static struct list_head *find_workspace(int type)
 	atomic_t *alloc_ws		= &btrfs_comp_ws[idx].alloc_ws;
 	wait_queue_head_t *ws_wait	= &btrfs_comp_ws[idx].ws_wait;
 	int *num_ws			= &btrfs_comp_ws[idx].num_ws;
+
+	if (type == BTRFS_ENCRYPT_AES)
+		return NULL;
+
 again:
 	spin_lock(ws_lock);
 	if (!list_empty(idle_ws)) {
@@ -824,6 +830,9 @@ static void free_workspace(int type, struct list_head *workspace)
 	wait_queue_head_t *ws_wait	= &btrfs_comp_ws[idx].ws_wait;
 	int *num_ws			= &btrfs_comp_ws[idx].num_ws;
 
+	if (!workspace)
+		return;
+
 	spin_lock(ws_lock);
 	if (*num_ws < num_online_cpus()) {
 		list_add(workspace, idle_ws);
@@ -862,6 +871,38 @@ static void free_workspaces(void)
 	}
 }
 
+void print_data_encode_status(struct inode *inode, int direction,
+					char *prefix, int type, int ret)
+{
+#ifdef CONFIG_BTRFS_DEBUG
+	char what[10];
+
+	if (type == BTRFS_ENCRYPT_AES) {
+		if (!direction)
+			strcpy(what, "Encrypt");
+		else
+			strcpy(what, "Decrypt");
+	} else {
+		if (!direction)
+			strcpy(what, "Compress");
+		else
+			strcpy(what, "Uncpress");
+	}
+
+	switch (ret) {
+	case 0:
+		pr_debug("%s %s: success     : inode %lu\n",what, prefix, inode->i_ino);
+		return;
+	case -ENOKEY:
+		pr_debug("%s %s: Failed NOKEY: inode %lu\n",what, prefix, inode->i_ino);
+		return;
+	default:
+		pr_debug("%s %s: Failed %d   : inode %lu\n",what, prefix, ret, inode->i_ino);
+	}
+#else
+#endif
+}
+
 /*
  * given an address space and start/len, compress the bytes.
  *
@@ -894,7 +935,7 @@ int btrfs_compress_pages(int type, struct address_space *mapping,
 	int ret;
 
 	workspace = find_workspace(type);
-	if (IS_ERR(workspace))
+	if (workspace && IS_ERR(workspace))
 		return PTR_ERR(workspace);
 
 	ret = btrfs_compress_op[type-1]->compress_pages(workspace, mapping,
@@ -903,6 +944,8 @@ int btrfs_compress_pages(int type, struct address_space *mapping,
 						      total_in, total_out,
 						      max_out);
 	free_workspace(type, workspace);
+
+	print_data_encode_status(mapping->host, 0, "    ", type, ret);
 	return ret;
 }
 
@@ -930,13 +973,14 @@ static int btrfs_decompress_biovec(int type, struct page **pages_in,
 	int ret;
 
 	workspace = find_workspace(type);
-	if (IS_ERR(workspace))
+	if (workspace && IS_ERR(workspace))
 		return PTR_ERR(workspace);
 
 	ret = btrfs_compress_op[type-1]->decompress_biovec(workspace, pages_in,
 							 disk_start,
 							 bvec, vcnt, srclen);
 	free_workspace(type, workspace);
+	print_data_encode_status(bvec->bv_page->mapping->host, 1, "bio ", type, ret);
 	return ret;
 }
 
@@ -952,7 +996,7 @@ int btrfs_decompress(int type, unsigned char *data_in, struct page *dest_page,
 	int ret;
 
 	workspace = find_workspace(type);
-	if (IS_ERR(workspace))
+	if (workspace && IS_ERR(workspace))
 		return PTR_ERR(workspace);
 
 	ret = btrfs_compress_op[type-1]->decompress(workspace, data_in,
@@ -960,6 +1004,7 @@ int btrfs_decompress(int type, unsigned char *data_in, struct page *dest_page,
 						  srclen, destlen);
 
 	free_workspace(type, workspace);
+	print_data_encode_status(dest_page->mapping->host, 1, "page", type, ret);
 	return ret;
 }
 
diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h
index 13a4dc0436c9..78e8f38dbf60 100644
--- a/fs/btrfs/compression.h
+++ b/fs/btrfs/compression.h
@@ -79,5 +79,6 @@ struct btrfs_compress_op {
 
 extern const struct btrfs_compress_op btrfs_zlib_compress;
 extern const struct btrfs_compress_op btrfs_lzo_compress;
+extern const struct btrfs_compress_op btrfs_encrypt_ops;
 
 #endif
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index bfe4a337fb4d..f30a92bf9c54 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -719,8 +719,9 @@ enum btrfs_compression_type {
 	BTRFS_COMPRESS_NONE  = 0,
 	BTRFS_COMPRESS_ZLIB  = 1,
 	BTRFS_COMPRESS_LZO   = 2,
-	BTRFS_COMPRESS_TYPES = 2,
-	BTRFS_COMPRESS_LAST  = 3,
+	BTRFS_ENCRYPT_AES    = 3,
+	BTRFS_COMPRESS_TYPES = 3,
+	BTRFS_COMPRESS_LAST  = 4,
 };
 
 struct btrfs_inode_item {
@@ -771,6 +772,7 @@ struct btrfs_dir_item {
  * still visible as a directory
  */
 #define BTRFS_ROOT_SUBVOL_DEAD		(1ULL << 48)
+#define BTRFS_ROOT_SUBVOL_ENCRYPT	(1ULL << 49)
 
 struct btrfs_root_item {
 	struct btrfs_inode_item inode;
@@ -814,7 +816,9 @@ struct btrfs_root_item {
 	struct btrfs_timespec otime;
 	struct btrfs_timespec stime;
 	struct btrfs_timespec rtime;
-	__le64 reserved[8]; /* for future */
+	char encrypt_algo[16];
+	char encrypt_keytag[16];
+	__le64 reserved[4]; /* for future */
 } __attribute__ ((__packed__));
 
 /*
@@ -2344,6 +2348,7 @@ do {                                                                   \
 #define BTRFS_INODE_NOATIME		(1 << 9)
 #define BTRFS_INODE_DIRSYNC		(1 << 10)
 #define BTRFS_INODE_COMPRESS		(1 << 11)
+#define BTRFS_INODE_ENCRYPT		(1 << 12)
 
 #define BTRFS_INODE_ROOT_ITEM_INIT	(1 << 31)
 
diff --git a/fs/btrfs/encrypt.c b/fs/btrfs/encrypt.c
new file mode 100644
index 000000000000..a6838cccc507
--- /dev/null
+++ b/fs/btrfs/encrypt.c
@@ -0,0 +1,544 @@
+/*
+ * Copyright (C) 2016 Oracle.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+#include <linux/string.h>
+#include <linux/crypto.h>
+#include <linux/scatterlist.h>
+#include <linux/random.h>
+#include <linux/pagemap.h>
+#include <keys/user-type.h>
+#include "compression.h"
+#include <linux/slab.h>
+#include <linux/keyctl.h>
+#include <linux/key-type.h>
+#include <linux/cred.h>
+#include <keys/user-type.h>
+#include "ctree.h"
+#include "btrfs_inode.h"
+#include "props.h"
+
+static const struct btrfs_encrypt_algorithm {
+	const char *name;
+	size_t	keylen;
+} btrfs_encrypt_algorithm_supported[] = {
+	{"aes", 16}
+};
+
+/*
+ * Returns cipher alg key size if the encryption type is found
+ * otherwise 0
+ */
+size_t btrfs_check_encrypt_type(char *type)
+{
+	int i;
+	for (i = 0; i < ARRAY_SIZE(btrfs_encrypt_algorithm_supported); i++)
+		if (!strcmp(btrfs_encrypt_algorithm_supported[i].name, type))
+			return btrfs_encrypt_algorithm_supported[i].keylen;
+
+	return 0;
+}
+
+/* key management*/
+static int btrfs_request_key(char *key_tag, void *key_data)
+{
+	int ret;
+	const struct user_key_payload *payload;
+	struct key *btrfs_key = NULL;
+
+	ret = 0;
+	btrfs_key = request_key(&key_type_user, key_tag, NULL);
+	if (IS_ERR(btrfs_key)) {
+		ret = PTR_ERR(btrfs_key);
+		btrfs_key = NULL;
+		return ret;
+	}
+
+	/*
+	 * caller just need key not payload so return
+	 */
+	if (!key_data)
+		return 0;
+
+	ret = key_validate(btrfs_key);
+	if (ret < 0)
+		goto out;
+
+	rcu_read_lock(); // TODO: check down_write key->sem ?
+	payload = user_key_payload(btrfs_key);
+	if (IS_ERR_OR_NULL(payload)) {
+		ret = PTR_ERR(payload);
+		goto out;
+	}
+
+	/*
+	 * As of now we just hard code as we just use ASE now
+	 */
+	if (payload->datalen != 16)
+		ret = -EINVAL;
+	else
+		memcpy(key_data, payload->data, 16);
+
+out:
+	rcu_read_unlock();
+	key_put(btrfs_key);
+
+	return ret;
+}
+
+static int btrfs_get_key_data_from_inode(struct inode *inode, unsigned char *keydata)
+{
+	int ret;
+	char keytag[15];
+	struct btrfs_inode *binode;
+	struct btrfs_root_item *ri;
+
+	binode = BTRFS_I(inode);
+	ri = &(binode->root->root_item);
+	strncpy(keytag, ri->encrypt_keytag, 14);
+	keytag[14] = '\0';
+
+	ret = btrfs_request_key(keytag, keydata);
+	return ret;
+}
+
+int btrfs_update_key_data_to_binode(struct inode *inode)
+{
+	int ret;
+	unsigned char keydata[16];
+	struct btrfs_inode *binode;
+
+	ret = btrfs_get_key_data_from_inode(inode, keydata);
+	if (ret)
+		return ret;
+
+	binode = BTRFS_I(inode);
+	memcpy(binode->key_payload, keydata, 16);
+
+	return ret;
+}
+
+int btrfs_get_keytag(struct address_space *mapping, char *keytag, struct inode **inode)
+{
+	struct btrfs_inode *binode;
+	struct btrfs_root_item *ri;
+
+	if (!mapping)
+		return -EINVAL;
+
+	if (!(mapping->host))
+		return -EINVAL;
+
+	binode = BTRFS_I(mapping->host);
+	ri = &(binode->root->root_item);
+
+	strncpy(keytag, ri->encrypt_keytag, 14);
+	keytag[14] = '\0';
+	if (inode)
+		*inode = &binode->vfs_inode;
+
+	return 0;
+}
+
+/* Encrypt and decrypt */
+struct workspace {
+	struct list_head list;
+};
+
+struct btrfs_crypt_result {
+	struct completion completion;
+	int err;
+};
+
+struct btrfs_ablkcipher_def {
+	struct scatterlist sg;
+	struct crypto_ablkcipher *tfm;
+	struct ablkcipher_request *req;
+	struct btrfs_crypt_result result;
+};
+
+int btrfs_do_blkcipher(int enc, char *data, size_t len)
+{
+	int ret = -EFAULT;
+	struct scatterlist sg;
+	unsigned int ivsize = 0;
+	char *cipher = "cbc(aes)";
+	struct blkcipher_desc desc;
+	struct crypto_blkcipher *blkcipher = NULL;
+	char *charkey =
+		"\x12\x34\x56\x78\x90\xab\xcd\xef\x12\x34\x56\x78\x90\xab\xcd\xef";
+	char *chariv =
+		"\x12\x34\x56\x78\x90\xab\xcd\xef\x12\x34\x56\x78\x90\xab\xcd\xef";
+
+	blkcipher = crypto_alloc_blkcipher(cipher, 0, 0);
+	if (IS_ERR(blkcipher)) {
+		printk("could not allocate blkcipher handle for %s\n", cipher);
+		return -PTR_ERR(blkcipher);
+	}
+
+	if (crypto_blkcipher_setkey(blkcipher, charkey, 16)) {
+		printk("key could not be set\n");
+		ret = -EAGAIN;
+		goto out;
+	}
+
+	ivsize = crypto_blkcipher_ivsize(blkcipher);
+	if (ivsize) {
+		if (ivsize != strlen(chariv)) {
+			printk("length differs from expected length\n");
+			ret = -EINVAL;
+			goto out;
+		}
+		crypto_blkcipher_set_iv(blkcipher, chariv, ivsize);
+	}
+
+	desc.flags = 0;
+	desc.tfm = blkcipher;
+	sg_init_one(&sg, data, len);
+
+	if (enc) {
+		/* encrypt data in place */
+		ret = crypto_blkcipher_encrypt(&desc, &sg, &sg, len);
+	} else {
+		/* decrypt data in place */
+		ret = crypto_blkcipher_decrypt(&desc, &sg, &sg, len);
+	}
+
+	return ret;
+
+out:
+	crypto_free_blkcipher(blkcipher);
+	return ret;
+}
+
+static void btrfs_ablkcipher_cb(struct crypto_async_request *req, int error)
+{
+	struct btrfs_crypt_result *result;
+
+	if (error == -EINPROGRESS) {
+		pr_info("Encryption callback reports error\n");
+		return;
+	}
+
+	result = req->data;
+	result->err = error;
+	complete(&result->completion);
+	pr_info("Encryption finished successfully\n");
+}
+
+static unsigned int btrfs_ablkcipher_encdec(struct btrfs_ablkcipher_def *ablk, int enc)
+{
+	int rc = 0;
+
+	if (enc)
+		rc = crypto_ablkcipher_encrypt(ablk->req);
+	else
+		rc = crypto_ablkcipher_decrypt(ablk->req);
+
+	switch (rc) {
+	case 0:
+		break;
+	case -EINPROGRESS:
+	case -EBUSY:
+		rc = wait_for_completion_interruptible(
+			&ablk->result.completion);
+		if (!rc && !ablk->result.err) {
+			reinit_completion(&ablk->result.completion);
+			break;
+		}
+	default:
+		pr_info("ablkcipher encrypt returned with %d result %d\n",
+		       rc, ablk->result.err);
+		break;
+	}
+	init_completion(&ablk->result.completion);
+
+	return rc;
+}
+
+void btrfs_cipher_get_ivdata(char **ivdata, unsigned int ivsize, unsigned int *ivdata_size)
+{
+	/* fixme */
+	if (0) {
+		*ivdata = kmalloc(ivsize, GFP_KERNEL);
+		get_random_bytes(ivdata, ivsize);
+		*ivdata_size = ivsize;
+	} else {
+		*ivdata = kstrdup(
+			"\x12\x34\x56\x78\x90\xab\xcd\xef\x12\x34\x56\x78\x90\xab\xcd\xef",
+			GFP_NOFS);
+		*ivdata_size = strlen(*ivdata);
+	}
+}
+
+static int btrfs_do_ablkcipher(int endec, struct page *page, unsigned long len,
+							struct inode *inode)
+{
+	int ret = -EFAULT;
+	unsigned char key_data[16];
+	char *ivdata = NULL;
+	unsigned int key_size;
+	unsigned int ivsize = 0;
+	unsigned int ivdata_size;
+	unsigned int ablksize = 0;
+	struct btrfs_ablkcipher_def ablk_akin;
+	struct ablkcipher_request *req = NULL;
+	struct crypto_ablkcipher *ablkcipher = NULL;
+
+	ret = 0;
+
+	if (!inode) {
+		BUG_ON("Need inode\n");
+		return -EINVAL;
+	}
+	/* get key from the inode */
+	ret = btrfs_get_key_data_from_inode(inode, key_data);
+
+	key_size = 16; //todo: defines, but review for suitable cipher
+
+	ablkcipher = crypto_alloc_ablkcipher("cts(cbc(aes))", 0, 0);
+	if (IS_ERR(ablkcipher)) {
+		pr_info("could not allocate ablkcipher handle\n");
+		return PTR_ERR(ablkcipher);
+	}
+
+	ablksize = crypto_ablkcipher_blocksize(ablkcipher);
+	/* we can't cipher a block less the ciper block size */
+	if (len < ablksize || len > PAGE_CACHE_SIZE) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	ivsize = crypto_ablkcipher_ivsize(ablkcipher);
+	if (ivsize) {
+		btrfs_cipher_get_ivdata(&ivdata, ivsize, &ivdata_size);
+		if (ivsize != ivdata_size) {
+			BUG_ON("IV length differs from expected length\n");
+			ret = -EINVAL;
+			goto out;
+		}
+	} else {
+		BUG_ON("This cipher doesn't need ivdata, but are we ready ?\n");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	req = ablkcipher_request_alloc(ablkcipher, GFP_KERNEL);
+	if (IS_ERR(req)) {
+		pr_info("could not allocate request queue\n");
+		ret = PTR_ERR(req);
+		goto out;
+	}
+
+	ablkcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
+					btrfs_ablkcipher_cb, &ablk_akin.result);
+
+	if (crypto_ablkcipher_setkey(ablkcipher, key_data, key_size)) {
+		printk("key could not be set\n");
+		ret = -EAGAIN;
+		goto out;
+	}
+
+	ablk_akin.tfm = ablkcipher;
+	ablk_akin.req = req;
+
+	sg_init_table(&ablk_akin.sg, 1);
+	sg_set_page(&ablk_akin.sg, page, len, 0);
+	ablkcipher_request_set_crypt(req, &ablk_akin.sg, &ablk_akin.sg, len, ivdata);
+
+	init_completion(&ablk_akin.result.completion);
+
+	ret = btrfs_ablkcipher_encdec(&ablk_akin, endec);
+
+out:
+	if (ablkcipher)
+		crypto_free_ablkcipher(ablkcipher);
+	if (req)
+		ablkcipher_request_free(req);
+
+	kfree(ivdata);
+
+	return ret;
+}
+
+static int btrfs_encrypt_pages(struct list_head *na_ws, struct address_space *mapping,
+			u64 start, unsigned long len, struct page **pages,
+			unsigned long nr_pages, unsigned long *na_out_pages,
+			unsigned long *na_total_in, unsigned long *na_total_out,
+			unsigned long na_max_out)
+{
+	int ret;
+	struct page *in_page;
+	struct page *out_page;
+	char *in;
+	char *out;
+	unsigned long bytes_left = len;
+	unsigned long cur_page_len;
+	unsigned long cur_page;
+	struct inode *inode;
+
+	*na_total_in = 0;
+	*na_out_pages = 0;
+
+	if (!mapping && !mapping->host) {
+		WARN_ON("Need mapped pages\n");
+		return -EINVAL;
+	}
+
+	inode = mapping->host;
+
+	for (cur_page = 0; cur_page < nr_pages; cur_page++) {
+
+		WARN_ON(!bytes_left);
+
+		in_page = find_get_page(mapping, start >> PAGE_CACHE_SHIFT);
+		out_page = alloc_page(GFP_NOFS| __GFP_HIGHMEM);
+		cur_page_len = min(bytes_left, PAGE_CACHE_SIZE);
+
+		in = kmap(in_page);
+		out = kmap(out_page);
+		memcpy(out, in, cur_page_len);
+		kunmap(out_page);
+		kunmap(in_page);
+
+		ret = btrfs_do_ablkcipher(1, out_page, cur_page_len, inode);
+		if (ret) {
+			__free_page(out_page);
+			return ret;
+		}
+
+		pages[cur_page] = out_page;
+		*na_out_pages = *na_out_pages + 1;
+		*na_total_in = *na_total_in + cur_page_len;
+
+		start += cur_page_len;
+		bytes_left = bytes_left - cur_page_len;
+	}
+
+	return ret;
+}
+
+static int btrfs_decrypt_pages(struct list_head *na_ws, unsigned char *in, struct page *out_page,
+				unsigned long na_start_byte, size_t in_size, size_t out_size)
+{
+	int ret;
+	char *out_addr;
+	char keytag[24];
+	struct address_space *mapping;
+	struct inode *inode;
+
+	if (!out_page)
+		return -EINVAL;
+
+	if (in_size > PAGE_CACHE_SIZE)
+		return -EINVAL;
+
+	memset(keytag, '\0', 24);
+
+	mapping = out_page->mapping;
+	if (!mapping && !mapping->host) {
+		WARN_ON("Need mapped pages\n");
+		return -EINVAL;
+	}
+
+	inode = mapping->host;
+
+	out_addr = kmap(out_page);
+	memcpy(out_addr, in, in_size);
+	kunmap(out_page);
+
+	ret = btrfs_do_ablkcipher(0, out_page, in_size, inode);
+
+	return ret;
+}
+
+static int btrfs_decrypt_pages_bio(struct list_head *na_ws, struct page **in_pages,
+					u64 in_start_offset, struct bio_vec *out_pages_bio,
+					int bi_vcnt, size_t in_len)
+{
+	char *in;
+	char *out;
+	int ret = 0;
+	struct page *in_page;
+	struct page *out_page;
+	unsigned long cur_page_n;
+	unsigned long bytes_left;
+	unsigned long in_nr_pages;
+	unsigned long cur_page_len;
+	unsigned long processed_len = 0;
+	struct address_space *mapping;
+	struct inode *inode;
+
+	if (na_ws)
+		return -EINVAL;
+
+	out_page = out_pages_bio[0].bv_page;
+	mapping = out_page->mapping;
+	if (!mapping && !mapping->host) {
+		WARN_ON("Need mapped page\n");
+		return -EINVAL;
+	}
+
+	inode = mapping->host;
+
+	in_nr_pages = DIV_ROUND_UP(in_len, PAGE_CACHE_SIZE);
+	bytes_left = in_len;
+	WARN_ON(in_nr_pages != bi_vcnt);
+
+	for (cur_page_n = 0; cur_page_n < in_nr_pages; cur_page_n++) {
+		WARN_ON(!bytes_left);
+
+		in_page = in_pages[cur_page_n];
+		out_page = out_pages_bio[cur_page_n].bv_page;
+
+		cur_page_len = min(bytes_left, PAGE_CACHE_SIZE);
+
+		in = kmap(in_page);
+		out = kmap(out_page);
+		memcpy(out, in, cur_page_len);
+		kunmap(out_page);
+		kunmap(in_page);
+
+		ret = btrfs_do_ablkcipher(0, out_page, cur_page_len, inode);
+
+		if (ret && ret != -ENOKEY)
+			goto error_out;
+
+		if (cur_page_len < PAGE_CACHE_SIZE) {
+			out = kmap(out_page);
+			memset(out + cur_page_len, 0, PAGE_CACHE_SIZE - cur_page_len);
+			kunmap(out_page);
+		}
+
+		bytes_left = bytes_left - cur_page_len;
+		processed_len = processed_len + cur_page_len;
+
+		//flush_dcache_page(out_page);
+	}
+	WARN_ON(processed_len != in_len);
+	WARN_ON(bytes_left);
+
+error_out:
+	return ret;
+}
+
+const struct btrfs_compress_op btrfs_encrypt_ops = {
+	.alloc_workspace	= NULL,
+	.free_workspace		= NULL,
+	.compress_pages		= btrfs_encrypt_pages,
+	.decompress_biovec	= btrfs_decrypt_pages_bio,
+	.decompress		= btrfs_decrypt_pages,
+};
diff --git a/fs/btrfs/encrypt.h b/fs/btrfs/encrypt.h
new file mode 100644
index 000000000000..36a7067e98b1
--- /dev/null
+++ b/fs/btrfs/encrypt.h
@@ -0,0 +1,21 @@
+/*
+ * Copyright (C) 2016 Oracle.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+
+size_t btrfs_check_encrypt_type(char *encryption_type);
+int btrfs_update_key_data_to_binode(struct inode *inode);
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 151b7c71b868..b27a89d89753 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -60,6 +60,7 @@
 #include "hash.h"
 #include "props.h"
 #include "qgroup.h"
+#include "encrypt.h"
 
 struct btrfs_iget_args {
 	struct btrfs_key *location;
@@ -206,6 +207,8 @@ static int insert_inline_extent(struct btrfs_trans_handle *trans,
 		}
 		btrfs_set_file_extent_compression(leaf, ei,
 						  compress_type);
+		if (compress_type == BTRFS_ENCRYPT_AES)
+			btrfs_set_file_extent_encryption(leaf, ei, 1);
 	} else {
 		page = find_get_page(inode->i_mapping,
 				     start >> PAGE_CACHE_SHIFT);
@@ -581,7 +584,7 @@ cont:
 		 * win, compare the page count read with the blocks on disk
 		 */
 		total_in = ALIGN(total_in, PAGE_CACHE_SIZE);
-		if (total_compressed >= total_in) {
+		if (total_compressed >= total_in && compress_type != BTRFS_ENCRYPT_AES) {
 			will_compress = 0;
 		} else {
 			num_bytes = total_in;
@@ -6704,6 +6707,8 @@ static noinline int uncompress_inline(struct btrfs_path *path,
 	max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size);
 	ret = btrfs_decompress(compress_type, tmp, page,
 			       extent_offset, inline_size, max_size);
+	if (ret && ret == -ENOKEY)
+		ret = 0;
 	kfree(tmp);
 	return ret;
 }
@@ -9271,6 +9276,20 @@ static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	u64 root_objectid;
 	int ret;
 	u64 old_ino = btrfs_ino(old_inode);
+	u64 root_flags;
+	u64 dest_flags;
+
+	/*
+	 * As of now block an encrypted file/dir to move across
+	 * subvol which potentially has different key.
+	 */
+	root_flags = btrfs_root_flags(&root->root_item);
+	dest_flags = btrfs_root_flags(&dest->root_item);
+	if (root != dest &&
+		((root_flags & BTRFS_ROOT_SUBVOL_ENCRYPT) ||
+		(dest_flags & BTRFS_ROOT_SUBVOL_ENCRYPT))) {
+		return -EOPNOTSUPP;
+	}
 
 	if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
 		return -EPERM;
@@ -9931,6 +9950,22 @@ static int btrfs_permission(struct inode *inode, int mask)
 		if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
 			return -EACCES;
 	}
+
+	/*
+	 * Get the required key as we encrypt only file data, this
+	 * this applies only files as of now.
+	 */
+	if (S_ISREG(mode)) {
+		int ret = 0;
+		u64 root_flags;
+		root_flags = btrfs_root_flags(&root->root_item);
+		if (root_flags & BTRFS_ROOT_SUBVOL_ENCRYPT) {
+			ret = btrfs_update_key_data_to_binode(inode);
+			if (ret)
+				return -ENOKEY;
+		}
+	}
+
 	return generic_permission(inode, mask);
 }
 
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 48aee9846329..3a0f40e4a713 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2139,8 +2139,15 @@ static noinline int btrfs_ioctl_tree_search(struct file *file,
 	int ret;
 	size_t buf_size;
 
+#if 0
+	/*
+	 * Todo: Workaround as of now instead of introduing a new ioctl,
+	 * so that non root user can find info about the subvol
+	 * they own/create. This must be fixed in final.
+	 */
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
+#endif
 
 	uargs = (struct btrfs_ioctl_search_args __user *)argp;
 
diff --git a/fs/btrfs/props.c b/fs/btrfs/props.c
index f9e60231f685..d40ace5f5492 100644
--- a/fs/btrfs/props.c
+++ b/fs/btrfs/props.c
@@ -22,10 +22,16 @@
 #include "hash.h"
 #include "transaction.h"
 #include "xattr.h"
+#include "encrypt.h"
 
 #define BTRFS_PROP_HANDLERS_HT_BITS 8
 static DEFINE_HASHTABLE(prop_handlers_ht, BTRFS_PROP_HANDLERS_HT_BITS);
 
+#define BTRFS_PROP_INHERIT_NONE		(1U << 0)
+#define BTRFS_PROP_INHERIT_FOR_DIR	(1U << 1)
+#define BTRFS_PROP_INHERIT_FOR_CLONE	(1U << 2)
+#define BTRFS_PROP_INHERIT_FOR_SUBVOL	(1U << 3)
+
 struct prop_handler {
 	struct hlist_node node;
 	const char *xattr_name;
@@ -41,13 +47,28 @@ static int prop_compression_apply(struct inode *inode,
 				  size_t len);
 static const char *prop_compression_extract(struct inode *inode);
 
+static int prop_encrypt_validate(const char *value, size_t len);
+static int prop_encrypt_apply(struct inode *inode,
+				  const char *value, size_t len);
+static const char *prop_encrypt_extract(struct inode *inode);
+
 static struct prop_handler prop_handlers[] = {
 	{
 		.xattr_name = XATTR_BTRFS_PREFIX "compression",
 		.validate = prop_compression_validate,
 		.apply = prop_compression_apply,
 		.extract = prop_compression_extract,
-		.inheritable = 1
+		.inheritable = BTRFS_PROP_INHERIT_FOR_DIR| \
+				BTRFS_PROP_INHERIT_FOR_CLONE| \
+				BTRFS_PROP_INHERIT_FOR_SUBVOL,
+	},
+	{
+		.xattr_name = XATTR_BTRFS_PREFIX "encrypt",
+		.validate = prop_encrypt_validate,
+		.apply = prop_encrypt_apply,
+		.extract = prop_encrypt_extract,
+		.inheritable = BTRFS_PROP_INHERIT_FOR_DIR| \
+				BTRFS_PROP_INHERIT_FOR_CLONE,
 	},
 };
 
@@ -315,6 +336,13 @@ static int inherit_props(struct btrfs_trans_handle *trans,
 		if (!h->inheritable)
 			continue;
 
+		//is_subvolume_inode(); ?
+		if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID) {
+			if (!strcmp(h->xattr_name, "btrfs.encrypt")) {
+				continue;
+			}
+		}
+
 		value = h->extract(parent);
 		if (!value)
 			continue;
@@ -425,4 +453,114 @@ static const char *prop_compression_extract(struct inode *inode)
 	return NULL;
 }
 
+static int btrfs_create_encrypt_key_tuplet(char *algo, char *tag, char *val_out)
+{
+	return snprintf(val_out, 32, "%s@%s", algo, tag);
+}
+
+static int btrfs_split_key_tuplet(const char *val, size_t len,
+					char *keyalgo, char *keytag)
+{
+	char *tmp;
+	char *tmp1;
+	char *tmp2;
+
+	tmp1 = tmp = kstrdup(val, GFP_NOFS);
+	tmp[len] = '\0';
+	tmp2 = strsep(&tmp, "@");
+	if (!tmp2) {
+		kfree(tmp1);
+		return -EINVAL;
+	}
+
+	if (strlen(tmp2) > 16 || strlen(tmp) > 16) {
+		kfree(tmp1);
+		return -EINVAL;
+	}
+	strcpy(keyalgo, tmp2);
+	strcpy(keytag, tmp);
+
+	return 0;
+}
+
+/*
+ * The required foramt in the value is <encrypt_algo>@<key_tag>
+ * eg: btrfs.encrypt="aes@btrfs:61e0d004"
+ */
+static int prop_encrypt_validate(const char *value, size_t len)
+{
+	int ret;
+	char keytag[16];
+	char keyalgo[16];
+	size_t keylen;
+
+	if (!len)
+		return 0;
+
+	ret = btrfs_split_key_tuplet(value, len, keyalgo, keytag);
+	if (ret)
+		return ret;
 
+	keylen = btrfs_check_encrypt_type(keyalgo);
+	if (!keylen)
+		return -ENOTSUPP;
+
+	return ret;
+}
+
+static int prop_encrypt_apply(struct inode *inode,
+				const char *value, size_t len)
+{
+	int ret;
+	u64 root_flags;
+	char keytag[16];
+	char keyalgo[16];
+	struct btrfs_root_item *root_item;
+
+	root_item = &(BTRFS_I(inode)->root->root_item);
+
+	if (len == 0) {
+		BTRFS_I(inode)->flags &= ~BTRFS_INODE_ENCRYPT;
+		BTRFS_I(inode)->force_compress = 0;
+
+		if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID) {
+			root_flags = btrfs_root_flags(root_item);
+			btrfs_set_root_flags(root_item, root_flags | ~BTRFS_ROOT_SUBVOL_ENCRYPT);
+			memset(root_item->encrypt_algo, '\0', 16);
+			memset(root_item->encrypt_keytag, '\0', 16);
+		}
+		return 0;
+	}
+
+	BTRFS_I(inode)->flags |= BTRFS_INODE_ENCRYPT;
+	BTRFS_I(inode)->force_compress = BTRFS_ENCRYPT_AES;
+
+	ret = btrfs_split_key_tuplet(value, len, keyalgo, keytag);
+	if (ret)
+		return ret;
+
+	/* do it only for the subvol or snapshot */
+	if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID) {
+		root_flags = btrfs_root_flags(root_item);
+		btrfs_set_root_flags(root_item, root_flags | BTRFS_ROOT_SUBVOL_ENCRYPT);
+		/* TODO: this is not right, fix it */
+		strncpy(root_item->encrypt_algo, keyalgo, 16);
+		strncpy(root_item->encrypt_keytag, keytag, 16);
+	}
+
+	return 0;
+}
+
+static const char *prop_encrypt_extract(struct inode *inode)
+{
+	int ret;
+	char val[32];
+	struct btrfs_root_item *ri;
+
+	ri = &(BTRFS_I(inode)->root->root_item);
+
+	ret = btrfs_create_encrypt_key_tuplet(ri->encrypt_algo,
+					ri->encrypt_keytag, val);
+
+	return kstrdup(val, GFP_NOFS);
+}
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index d41e09fe8e38..400225890f5f 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -59,10 +59,10 @@
 #include "free-space-cache.h"
 #include "backref.h"
 #include "tests/btrfs-tests.h"
-
 #include "qgroup.h"
 #define CREATE_TRACE_POINTS
 #include <trace/events/btrfs.h>
+#include "encrypt.h"
 
 static const struct super_operations btrfs_super_ops;
 static struct file_system_type btrfs_fs_type;
@@ -92,6 +92,9 @@ const char *btrfs_decode_error(int errno)
 	case -ENOENT:
 		errstr = "No such entry";
 		break;
+	case -ENOKEY:
+		errstr = "Required key not available";
+		break;
 	}
 
 	return errstr;
-- 
2.7.0