MDEV-8272: Encryption performance: Reduce the number of unused memcpy's

Removed memcpy's on cases when page is not encrypted and make sure
we use the correct buffer for reading/writing.

storage/innobase/buf/buf0buf.cc

@@ -5714,30 +5714,31 @@ Encrypts a buffer page right before it's flushed to disk
 byte*
 buf_page_encrypt_before_write(
 /*==========================*/
-	buf_page_t* bpage,     /*!< in/out: buffer page to be flushed */
-	const byte* src_frame, /*!< in: src frame */
-	ulint space_id) /*!< in: space id */
+	buf_page_t*	bpage,		/*!< in/out: buffer page to be flushed */
+	byte*		src_frame,	/*!< in: src frame */
+	ulint		space_id)	/*!< in: space id */
 {
 	fil_space_crypt_t* crypt_data = fil_space_get_crypt_data(space_id);
 	ulint zip_size = buf_page_get_zip_size(bpage);
 	ulint page_size = (zip_size) ? zip_size : UNIV_PAGE_SIZE;
 	buf_pool_t* buf_pool = buf_pool_from_bpage(bpage);
 	bool page_compressed = fil_space_is_page_compressed(bpage->space);
-	bpage->real_size = UNIV_PAGE_SIZE;
 	bool encrypted = true;
 
+	bpage->real_size = UNIV_PAGE_SIZE;
+
 	fil_page_type_validate(src_frame);
 
 	if (bpage->offset == 0) {
 		/* Page 0 of a tablespace is not encrypted/compressed */
 		ut_ad(bpage->key_version == 0);
-		return const_cast<byte*>(src_frame);
+		return src_frame;
 	}
 
 	if (bpage->space == TRX_SYS_SPACE && bpage->offset == TRX_SYS_PAGE_NO) {
 		/* don't encrypt/compress page as it contains address to dblwr buffer */
 		bpage->key_version = 0;
-		return const_cast<byte*>(src_frame);
+		return src_frame;
 	}
 
 	if (crypt_data != NULL && crypt_data->encryption == FIL_SPACE_ENCRYPTION_OFF) {
@@ -5759,31 +5760,35 @@ buf_page_encrypt_before_write(
 
 	if (!encrypted && !page_compressed) {
 		/* No need to encrypt or page compress the page */
-		return const_cast<byte*>(src_frame);
+		return src_frame;
 	}
 
 	/* Find free slot from temporary memory array */
 	buf_tmp_buffer_t* slot = buf_pool_reserve_tmp_slot(buf_pool, page_compressed);
+	slot->out_buf = NULL;
 	bpage->slot = slot;
 
-	byte *dst_frame = bpage->slot->out_buf = slot->crypt_buf;
+	byte *dst_frame = slot->crypt_buf;
 
 	if (!page_compressed) {
 		/* Encrypt page content */
-		fil_space_encrypt(bpage->space,
-				bpage->offset,
-				bpage->newest_modification,
-				src_frame,
-				zip_size,
-				dst_frame);
+		byte* tmp = fil_space_encrypt(bpage->space,
+					      bpage->offset,
+					      bpage->newest_modification,
+					      src_frame,
+					      zip_size,
+					      dst_frame);
 
 		unsigned key_version =
 			mach_read_from_4(dst_frame + FIL_PAGE_FILE_FLUSH_LSN_OR_KEY_VERSION);
 		ut_ad(key_version == 0 || key_version >= bpage->key_version);
 		bpage->key_version = key_version;
 		bpage->real_size = page_size;
+		slot->out_buf = dst_frame = tmp;
 
-		fil_page_type_validate(dst_frame);
+#ifdef UNIV_DEBUG
+		fil_page_type_validate(tmp);
+#endif
 
 	} else {
 		/* First we compress the page content */
@@ -5803,22 +5808,27 @@ buf_page_encrypt_before_write(
 
 		bpage->real_size = out_len;
 
+#ifdef UNIV_DEBUG
 		fil_page_type_validate(tmp);
+#endif
+
 		if(encrypted) {
 
 			/* And then we encrypt the page content */
-			fil_space_encrypt(bpage->space,
-				bpage->offset,
-				bpage->newest_modification,
-		        	tmp,
-				zip_size,
-				dst_frame);
-		} else {
-			bpage->slot->out_buf = dst_frame = tmp;
+			tmp = fil_space_encrypt(bpage->space,
+						bpage->offset,
+						bpage->newest_modification,
+						tmp,
+						zip_size,
+						dst_frame);
 		}
+
+		slot->out_buf = dst_frame = tmp;
 	}
 
+#ifdef UNIV_DEBUG
 	fil_page_type_validate(dst_frame);
+#endif
 
 	// return dst_frame which will be written
 	return dst_frame;
@@ -5830,7 +5840,7 @@ Decrypt page after it has been read from disk
 ibool
 buf_page_decrypt_after_read(
 /*========================*/
-	buf_page_t* bpage) /*!< in/out: buffer page read from disk */
+	buf_page_t*	bpage)	/*!< in/out: buffer page read from disk */
 {
 	ulint zip_size = buf_page_get_zip_size(bpage);
 	ulint size = (zip_size) ? zip_size : UNIV_PAGE_SIZE;
@@ -5855,8 +5865,11 @@ buf_page_decrypt_after_read(
 		/* Find free slot from temporary memory array */
 		buf_tmp_buffer_t* slot = buf_pool_reserve_tmp_slot(buf_pool, page_compressed);
 
+#ifdef UNIV_DEBUG
 		fil_page_type_validate(dst_frame);
+#endif
 
+		/* decompress using comp_buf to dst_frame */
 		fil_decompress_page(slot->comp_buf,
 			dst_frame,
 			size,
@@ -5866,24 +5879,27 @@ buf_page_decrypt_after_read(
 		slot->reserved = false;
 		key_version = 0;
 
+#ifdef UNIV_DEBUG
 		fil_page_type_validate(dst_frame);
+#endif
 	} else {
 		buf_tmp_buffer_t* slot = NULL;
 
 		if (key_version) {
 			/* Find free slot from temporary memory array */
 			slot = buf_pool_reserve_tmp_slot(buf_pool, page_compressed);
-			memcpy(slot->crypt_buf, dst_frame, size);
 
+#ifdef UNIV_DEBUG
 			fil_page_type_validate(dst_frame);
-			fil_page_type_validate(slot->crypt_buf);
-			/* decrypt from crypt_buf to dst_frame */
+#endif
+			/* decrypt using crypt_buf to dst_frame */
 			fil_space_decrypt(bpage->space,
-				slot->crypt_buf,
-				size,
-				dst_frame);
+					  slot->crypt_buf,
+					  size,
+					  dst_frame);
+#ifdef UNIV_DEBUG
 			fil_page_type_validate(dst_frame);
-			fil_page_type_validate(slot->crypt_buf);
+#endif
 		}
 
 		if (page_compressed_encrypted) {
@@ -5894,13 +5910,16 @@ buf_page_decrypt_after_read(
 #ifdef UNIV_DEBUG
 			fil_page_type_validate(dst_frame);
 #endif
+			/* decompress using comp_buf to dst_frame */
 			fil_decompress_page(slot->comp_buf,
 					dst_frame,
 					size,
 					&bpage->write_size);
 		}
 
+#ifdef UNIV_DEBUG
 		fil_page_type_validate(dst_frame);
+#endif
 
 		/* Mark this slot as free */
 		if (slot) {

storage/innobase/buf/buf0dblwr.cc

 /*****************************************************************************
 
 Copyright (c) 1995, 2014, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2013, 2014, SkySQL Ab. All Rights Reserved.
+Copyright (c) 2013, 2015, MariaDB Corporation. 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 as published by the Free Software
@@ -391,11 +391,11 @@ buf_dblwr_init_or_load_pages(
 	doublewrite = read_buf + TRX_SYS_DOUBLEWRITE;
 
 	if (mach_read_from_4(read_buf + FIL_PAGE_FILE_FLUSH_LSN_OR_KEY_VERSION) != 0) {
-		fil_space_decrypt((ulint)TRX_SYS_SPACE,
-				  read_buf,
-				  UNIV_PAGE_SIZE, /* page size */
-				  read_buf + UNIV_PAGE_SIZE);
-		doublewrite = read_buf + UNIV_PAGE_SIZE + TRX_SYS_DOUBLEWRITE;
+		byte* tmp = fil_space_decrypt((ulint)TRX_SYS_SPACE,
+						read_buf + UNIV_PAGE_SIZE,
+						UNIV_PAGE_SIZE, /* page size */
+						read_buf);
+		doublewrite = tmp + TRX_SYS_DOUBLEWRITE;
 	}
 
 	if (mach_read_from_4(doublewrite + TRX_SYS_DOUBLEWRITE_MAGIC)

storage/innobase/fil/fil0crypt.cc

@@ -545,13 +545,13 @@ fil_space_clear_crypt_data(
 /******************************************************************
 Encrypt a page */
 UNIV_INTERN
-void
+byte*
 fil_space_encrypt(
 /*==============*/
 	ulint		space,		/*!< in: Space id */
 	ulint		offset,		/*!< in: Page offset */
 	lsn_t		lsn,		/*!< in: lsn */
-	const byte*	src_frame,	/*!< in: Source page to be encrypted */
+	byte*		src_frame,	/*!< in: Source page to be encrypted */
 	ulint		zip_size,	/*!< in: compressed size if
 					row_format compressed */
 	byte*		dst_frame)	/*!< in: outbut buffer */
@@ -566,18 +566,14 @@ fil_space_encrypt(
 		|| orig_page_type==FIL_PAGE_TYPE_XDES) {
 		/* File space header or extent descriptor do not need to be
 		encrypted. */
-		//TODO: is this really needed ?
-		memcpy(dst_frame, src_frame, page_size);
-		return;
+		return src_frame;
 	}
 
 	/* Get crypt data from file space */
 	crypt_data = fil_space_get_crypt_data(space);
 
 	if (crypt_data == NULL) {
-		//TODO: Is this really needed ?
-		memcpy(dst_frame, src_frame, page_size);
-		return;
+		return src_frame;
 	}
 
 	ut_ad(crypt_data->encryption != FIL_SPACE_ENCRYPTION_OFF);
@@ -663,6 +659,8 @@ fil_space_encrypt(
 	mach_write_to_4(dst_frame + FIL_PAGE_FILE_FLUSH_LSN_OR_KEY_VERSION + 4, checksum);
 
 	srv_stats.pages_encrypted.inc();
+
+	return dst_frame;
 }
 
 /*********************************************************************
@@ -693,24 +691,22 @@ fil_space_check_encryption_read(
 
 /******************************************************************
 Decrypt a page
-@return true if page was encrypted */
+@return true if page decrypted, false if not.*/
 UNIV_INTERN
 bool
 fil_space_decrypt(
 /*==============*/
 	fil_space_crypt_t*	crypt_data,	/*!< in: crypt data */
-	const byte*		src_frame,	/*!< in: input buffer */
+	byte*			tmp_frame,	/*!< in: temporary buffer */
 	ulint			page_size,	/*!< in: page size */
-	byte*			dst_frame)	/*!< out: output buffer */
+	byte*			src_frame)	/*!< in:out: page buffer */
 {
 	ulint page_type = mach_read_from_2(src_frame+FIL_PAGE_TYPE);
 	uint key_version = mach_read_from_4(src_frame + FIL_PAGE_FILE_FLUSH_LSN_OR_KEY_VERSION);
 	bool page_compressed = (page_type == FIL_PAGE_PAGE_COMPRESSED_ENCRYPTED);
 
 	if (key_version == ENCRYPTION_KEY_NOT_ENCRYPTED) {
-		//TODO: is this really needed ?
-		memcpy(dst_frame, src_frame, page_size);
-		return false; /* page not decrypted */
+		return false;
 	}
 
 	ut_ad(crypt_data->encryption != FIL_SPACE_ENCRYPTION_OFF);
@@ -723,11 +719,11 @@ fil_space_decrypt(
 	ib_uint64_t lsn = mach_read_from_8(src_frame + FIL_PAGE_LSN);
 
 	/* Copy FIL page header, it is not encrypted */
-	memcpy(dst_frame, src_frame, FIL_PAGE_DATA);
+	memcpy(tmp_frame, src_frame, FIL_PAGE_DATA);
 
 	/* Calculate the offset where decryption starts */
 	const byte* src = src_frame + FIL_PAGE_DATA;
-	byte* dst = dst_frame + FIL_PAGE_DATA;
+	byte* dst = tmp_frame + FIL_PAGE_DATA;
 	uint32 dstlen = 0;
 	ulint srclen = page_size - (FIL_PAGE_DATA + FIL_PAGE_DATA_END);
 
@@ -751,12 +747,12 @@ fil_space_decrypt(
 	to sector boundary is written. */
 	if (!page_compressed) {
 		/* Copy FIL trailer */
-		memcpy(dst_frame + page_size - FIL_PAGE_DATA_END,
+		memcpy(tmp_frame + page_size - FIL_PAGE_DATA_END,
 		       src_frame + page_size - FIL_PAGE_DATA_END,
 		       FIL_PAGE_DATA_END);
 
 		// clear key-version & crypt-checksum from dst
-		memset(dst_frame + FIL_PAGE_FILE_FLUSH_LSN_OR_KEY_VERSION, 0, 8);
+		memset(tmp_frame + FIL_PAGE_FILE_FLUSH_LSN_OR_KEY_VERSION, 0, 8);
 	}
 
 	srv_stats.pages_decrypted.inc();
@@ -765,18 +761,31 @@ fil_space_decrypt(
 }
 
 /******************************************************************
-Decrypt a page */
+Decrypt a page
+@return encrypted page, or original not encrypted page if encryption is
+not needed. */
 UNIV_INTERN
-void
+byte*
 fil_space_decrypt(
 /*==============*/
 	ulint		space,		/*!< in: Fil space id */
-	const byte*	src_frame,	/*!< in: input buffer */
+	byte*		tmp_frame,	/*!< in: temporary buffer */
 	ulint		page_size,	/*!< in: page size */
-	byte*		dst_frame)	/*!< out: output buffer */
+	byte*		src_frame)	/*!< in/out: page buffer */
 {
-	fil_space_decrypt(fil_space_get_crypt_data(space),
-			  src_frame, page_size, dst_frame);
+	bool encrypted = fil_space_decrypt(
+				fil_space_get_crypt_data(space),
+				tmp_frame,
+				page_size,
+				src_frame);
+
+	if (encrypted) {
+		/* Copy the decrypted page back to page buffer, not
+		really any other options. */
+		memcpy(src_frame, tmp_frame, page_size);
+	}
+
+	return src_frame;
 }
 
 /*********************************************************************

storage/innobase/fil/fil0fil.cc

@@ -6410,14 +6410,19 @@ fil_iterate(
 		for (ulint i = 0; i < n_pages_read; ++i) {
 
 			if (iter.crypt_data != NULL) {
+				ulint size = iter.page_size;
 				bool decrypted = fil_space_decrypt(
-					iter.crypt_data,
-					readptr + i * iter.page_size,    // src
-					iter.page_size,
-					io_buffer + i * iter.page_size); // dst
+							iter.crypt_data,
+							io_buffer + i * size, //dst
+							iter.page_size,
+							readptr + i * size); // src
+
 				if (decrypted) {
 					/* write back unencrypted page */
 					updated = true;
+				} else {
+					/* TODO: remove unnecessary memcpy's */
+					memcpy(io_buffer + i * size, readptr + i * size, size);
 				}
 			}
 

storage/innobase/include/buf0buf.h

@@ -1449,9 +1449,9 @@ UNIV_INTERN
 byte*
 buf_page_encrypt_before_write(
 /*==========================*/
-	buf_page_t* page, /*!< in/out: buffer page to be flushed */
-	const byte* frame,
-	ulint space_id);
+	buf_page_t*	page,		/*!< in/out: buffer page to be flushed */
+	byte*		frame,		/*!< in: src frame */
+	ulint		space_id);	/*!< in: space id */
 
 /**********************************************************************
 The hook that is called after page is written to disk.

storage/innobase/include/fil0crypt.h

 /*****************************************************************************
-
+Copyright (C) 2013, 2015, Google Inc. All Rights Reserved.
 Copyright (c) 2015, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
@@ -197,43 +197,45 @@ bool
 fil_space_check_encryption_read(
 /*============================*/
 	ulint space);          /*!< in: tablespace id */
-
-/*********************************************************************
-Encrypt buffer page */
+/******************************************************************
+Decrypt a page
+@return true if page is decrypted, false if not. */
 UNIV_INTERN
-void
-fil_space_encrypt(
+bool
+fil_space_decrypt(
 /*==============*/
-	ulint space,          /*!< in: tablespace id */
-	ulint offset,         /*!< in: page no */
-	lsn_t lsn,            /*!< in: page lsn */
-	const byte* src_frame,/*!< in: page frame */
-	ulint size,           /*!< in: size of data to encrypt */
-	byte* dst_frame);      /*!< in: where to encrypt to */
+	fil_space_crypt_t*	crypt_data,	/*!< in: crypt data */
+	byte*			tmp_frame,	/*!< in: temporary buffer */
+	ulint			page_size,	/*!< in: page size */
+	byte*			src_frame);	/*!< in:out: page buffer */
 
 /*********************************************************************
-Decrypt buffer page */
+Encrypt buffer page
+@return encrypted page, or original not encrypted page if encrypt
+is not needed. */
 UNIV_INTERN
-void
-fil_space_decrypt(
+byte*
+fil_space_encrypt(
 /*==============*/
-	ulint space,          /*!< in: tablespace id */
-	const byte* src_frame,/*!< in: page frame */
-	ulint page_size,      /*!< in: size of data to encrypt */
-	byte* dst_frame);     /*!< in: where to decrypt to */
-
+	ulint	space,		/*!< in: tablespace id */
+	ulint	offset,		/*!< in: page no */
+	lsn_t	lsn,		/*!< in: page lsn */
+	byte*	src_frame,	/*!< in: page frame */
+	ulint	size,		/*!< in: size of data to encrypt */
+	byte*	dst_frame);	/*!< in: where to encrypt to */
 
 /*********************************************************************
 Decrypt buffer page
-@return true if page was encrypted */
+@return decrypted page, or original not encrypted page if decrypt is
+not needed.*/
 UNIV_INTERN
-bool
+byte*
 fil_space_decrypt(
 /*==============*/
-	fil_space_crypt_t* crypt_data, /*!< in: crypt data */
-	const byte* src_frame,/*!< in: page frame */
-	ulint page_size,      /*!< in: page size */
-	byte* dst_frame);     /*!< in: where to decrypt to */
+	ulint	space,		/*!< in: tablespace id */
+	byte*	src_frame,	/*!< in: page frame */
+	ulint	page_size,	/*!< in: size of data to encrypt */
+	byte*	dst_frame);	/*!< in: where to decrypt to */
 
 /*********************************************************************
 fil_space_verify_crypt_checksum

storage/xtradb/buf/buf0buf.cc

@@ -5873,30 +5873,31 @@ Encrypts a buffer page right before it's flushed to disk
 byte*
 buf_page_encrypt_before_write(
 /*==========================*/
-	buf_page_t* bpage,     /*!< in/out: buffer page to be flushed */
-	const byte* src_frame, /*!< in: src frame */
-	ulint space_id) /*!< in: space id */
+	buf_page_t*	bpage,		/*!< in/out: buffer page to be flushed */
+	byte*		src_frame,	/*!< in: src frame */
+	ulint		space_id)	/*!< in: space id */
 {
 	fil_space_crypt_t* crypt_data = fil_space_get_crypt_data(space_id);
 	ulint zip_size = buf_page_get_zip_size(bpage);
 	ulint page_size = (zip_size) ? zip_size : UNIV_PAGE_SIZE;
 	buf_pool_t* buf_pool = buf_pool_from_bpage(bpage);
 	bool page_compressed = fil_space_is_page_compressed(bpage->space);
-	bpage->real_size = UNIV_PAGE_SIZE;
 	bool encrypted = true;
 
+	bpage->real_size = UNIV_PAGE_SIZE;
+
 	fil_page_type_validate(src_frame);
 
 	if (bpage->offset == 0) {
 		/* Page 0 of a tablespace is not encrypted/compressed */
 		ut_ad(bpage->key_version == 0);
-		return const_cast<byte*>(src_frame);
+		return src_frame;
 	}
 
 	if (bpage->space == TRX_SYS_SPACE && bpage->offset == TRX_SYS_PAGE_NO) {
 		/* don't encrypt/compress page as it contains address to dblwr buffer */
 		bpage->key_version = 0;
-		return const_cast<byte*>(src_frame);
+		return src_frame;
 	}
 
 	if (crypt_data != NULL && crypt_data->encryption == FIL_SPACE_ENCRYPTION_OFF) {
@@ -5918,31 +5919,35 @@ buf_page_encrypt_before_write(
 
 	if (!encrypted && !page_compressed) {
 		/* No need to encrypt or page compress the page */
-		return const_cast<byte*>(src_frame);
+		return src_frame;
 	}
 
 	/* Find free slot from temporary memory array */
 	buf_tmp_buffer_t* slot = buf_pool_reserve_tmp_slot(buf_pool, page_compressed);
+	slot->out_buf = NULL;
 	bpage->slot = slot;
 
-	byte *dst_frame = bpage->slot->out_buf = slot->crypt_buf;
+	byte *dst_frame = slot->crypt_buf;
 
 	if (!page_compressed) {
 		/* Encrypt page content */
-		fil_space_encrypt(bpage->space,
-				bpage->offset,
-				bpage->newest_modification,
-				src_frame,
-				zip_size,
-				dst_frame);
+		byte* tmp = fil_space_encrypt(bpage->space,
+					      bpage->offset,
+					      bpage->newest_modification,
+					      src_frame,
+					      zip_size,
+					      dst_frame);
 
 		unsigned key_version =
 			mach_read_from_4(dst_frame + FIL_PAGE_FILE_FLUSH_LSN_OR_KEY_VERSION);
 		ut_ad(key_version == 0 || key_version >= bpage->key_version);
 		bpage->key_version = key_version;
 		bpage->real_size = page_size;
+		slot->out_buf = dst_frame = tmp;
 
-		fil_page_type_validate(dst_frame);
+#ifdef UNIV_DEBUG
+		fil_page_type_validate(tmp);
+#endif
 
 	} else {
 		/* First we compress the page content */
@@ -5962,22 +5967,27 @@ buf_page_encrypt_before_write(
 
 		bpage->real_size = out_len;
 
+#ifdef UNIV_DEBUG
 		fil_page_type_validate(tmp);
+#endif
+
 		if(encrypted) {
 
 			/* And then we encrypt the page content */
-			fil_space_encrypt(bpage->space,
-				bpage->offset,
-				bpage->newest_modification,
-		        	tmp,
-				zip_size,
-				dst_frame);
-		} else {
-			bpage->slot->out_buf = dst_frame = tmp;
+			tmp = fil_space_encrypt(bpage->space,
+						bpage->offset,
+						bpage->newest_modification,
+						tmp,
+						zip_size,
+						dst_frame);
 		}
+
+		slot->out_buf = dst_frame = tmp;
 	}
 
+#ifdef UNIV_DEBUG
 	fil_page_type_validate(dst_frame);
+#endif
 
 	// return dst_frame which will be written
 	return dst_frame;
@@ -5989,7 +5999,7 @@ Decrypt page after it has been read from disk
 ibool
 buf_page_decrypt_after_read(
 /*========================*/
-	buf_page_t* bpage) /*!< in/out: buffer page read from disk */
+	buf_page_t*	bpage)	/*!< in/out: buffer page read from disk */
 {
 	ulint zip_size = buf_page_get_zip_size(bpage);
 	ulint size = (zip_size) ? zip_size : UNIV_PAGE_SIZE;
@@ -6014,8 +6024,11 @@ buf_page_decrypt_after_read(
 		/* Find free slot from temporary memory array */
 		buf_tmp_buffer_t* slot = buf_pool_reserve_tmp_slot(buf_pool, page_compressed);
 
+#ifdef UNIV_DEBUG
 		fil_page_type_validate(dst_frame);
+#endif
 
+		/* decompress using comp_buf to dst_frame */
 		fil_decompress_page(slot->comp_buf,
 			dst_frame,
 			size,
@@ -6025,24 +6038,27 @@ buf_page_decrypt_after_read(
 		slot->reserved = false;
 		key_version = 0;
 
+#ifdef UNIV_DEBUG
 		fil_page_type_validate(dst_frame);
+#endif
 	} else {
 		buf_tmp_buffer_t* slot = NULL;
 
 		if (key_version) {
 			/* Find free slot from temporary memory array */
 			slot = buf_pool_reserve_tmp_slot(buf_pool, page_compressed);
-			memcpy(slot->crypt_buf, dst_frame, size);
 
+#ifdef UNIV_DEBUG
 			fil_page_type_validate(dst_frame);
-			fil_page_type_validate(slot->crypt_buf);
-			/* decrypt from crypt_buf to dst_frame */
+#endif
+			/* decrypt using crypt_buf to dst_frame */
 			fil_space_decrypt(bpage->space,
-				slot->crypt_buf,
-				size,
-				dst_frame);
+					  slot->crypt_buf,
+					  size,
+					  dst_frame);
+#ifdef UNIV_DEBUG
 			fil_page_type_validate(dst_frame);
-			fil_page_type_validate(slot->crypt_buf);
+#endif
 		}
 
 		if (page_compressed_encrypted) {
@@ -6053,13 +6069,16 @@ buf_page_decrypt_after_read(
 #ifdef UNIV_DEBUG
 			fil_page_type_validate(dst_frame);
 #endif
+			/* decompress using comp_buf to dst_frame */
 			fil_decompress_page(slot->comp_buf,
 					dst_frame,
 					size,
 					&bpage->write_size);
 		}
 
+#ifdef UNIV_DEBUG
 		fil_page_type_validate(dst_frame);
+#endif
 
 		/* Mark this slot as free */
 		if (slot) {

storage/xtradb/buf/buf0dblwr.cc

 /*****************************************************************************
 
 Copyright (c) 1995, 2014, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2013, 2014, SkySQL Ab. All Rights Reserved.
+Copyright (c) 2013, 2015, MariaDB Corporation. 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 as published by the Free Software
@@ -391,11 +391,11 @@ buf_dblwr_init_or_load_pages(
 	doublewrite = read_buf + TRX_SYS_DOUBLEWRITE;
 
 	if (mach_read_from_4(read_buf + FIL_PAGE_FILE_FLUSH_LSN_OR_KEY_VERSION) != 0) {
-		fil_space_decrypt((ulint)TRX_SYS_SPACE,
-				  read_buf,
-				  UNIV_PAGE_SIZE, /* page size */
-				  read_buf + UNIV_PAGE_SIZE);
-		doublewrite = read_buf + UNIV_PAGE_SIZE + TRX_SYS_DOUBLEWRITE;
+		byte* tmp = fil_space_decrypt((ulint)TRX_SYS_SPACE,
+						read_buf + UNIV_PAGE_SIZE,
+						UNIV_PAGE_SIZE, /* page size */
+						read_buf);
+		doublewrite = tmp + TRX_SYS_DOUBLEWRITE;
 	}
 
 	if (mach_read_from_4(doublewrite + TRX_SYS_DOUBLEWRITE_MAGIC)

storage/xtradb/fil/fil0crypt.cc

@@ -545,13 +545,13 @@ fil_space_clear_crypt_data(
 /******************************************************************
 Encrypt a page */
 UNIV_INTERN
-void
+byte*
 fil_space_encrypt(
 /*==============*/
 	ulint		space,		/*!< in: Space id */
 	ulint		offset,		/*!< in: Page offset */
 	lsn_t		lsn,		/*!< in: lsn */
-	const byte*	src_frame,	/*!< in: Source page to be encrypted */
+	byte*		src_frame,	/*!< in: Source page to be encrypted */
 	ulint		zip_size,	/*!< in: compressed size if
 					row_format compressed */
 	byte*		dst_frame)	/*!< in: outbut buffer */
@@ -566,18 +566,14 @@ fil_space_encrypt(
 		|| orig_page_type==FIL_PAGE_TYPE_XDES) {
 		/* File space header or extent descriptor do not need to be
 		encrypted. */
-		//TODO: is this really needed ?
-		memcpy(dst_frame, src_frame, page_size);
-		return;
+		return src_frame;
 	}
 
 	/* Get crypt data from file space */
 	crypt_data = fil_space_get_crypt_data(space);
 
 	if (crypt_data == NULL) {
-		//TODO: Is this really needed ?
-		memcpy(dst_frame, src_frame, page_size);
-		return;
+		return src_frame;
 	}
 
 	ut_ad(crypt_data->encryption != FIL_SPACE_ENCRYPTION_OFF);
@@ -663,6 +659,8 @@ fil_space_encrypt(
 	mach_write_to_4(dst_frame + FIL_PAGE_FILE_FLUSH_LSN_OR_KEY_VERSION + 4, checksum);
 
 	srv_stats.pages_encrypted.inc();
+
+	return dst_frame;
 }
 
 /*********************************************************************
@@ -693,24 +691,22 @@ fil_space_check_encryption_read(
 
 /******************************************************************
 Decrypt a page
-@return true if page was encrypted */
+@return true if page decrypted, false if not.*/
 UNIV_INTERN
 bool
 fil_space_decrypt(
 /*==============*/
 	fil_space_crypt_t*	crypt_data,	/*!< in: crypt data */
-	const byte*		src_frame,	/*!< in: input buffer */
+	byte*			tmp_frame,	/*!< in: temporary buffer */
 	ulint			page_size,	/*!< in: page size */
-	byte*			dst_frame)	/*!< out: output buffer */
+	byte*			src_frame)	/*!< in:out: page buffer */
 {
 	ulint page_type = mach_read_from_2(src_frame+FIL_PAGE_TYPE);
 	uint key_version = mach_read_from_4(src_frame + FIL_PAGE_FILE_FLUSH_LSN_OR_KEY_VERSION);
 	bool page_compressed = (page_type == FIL_PAGE_PAGE_COMPRESSED_ENCRYPTED);
 
 	if (key_version == ENCRYPTION_KEY_NOT_ENCRYPTED) {
-		//TODO: is this really needed ?
-		memcpy(dst_frame, src_frame, page_size);
-		return false; /* page not decrypted */
+		return false;
 	}
 
 	ut_ad(crypt_data->encryption != FIL_SPACE_ENCRYPTION_OFF);
@@ -723,11 +719,11 @@ fil_space_decrypt(
 	ib_uint64_t lsn = mach_read_from_8(src_frame + FIL_PAGE_LSN);
 
 	/* Copy FIL page header, it is not encrypted */
-	memcpy(dst_frame, src_frame, FIL_PAGE_DATA);
+	memcpy(tmp_frame, src_frame, FIL_PAGE_DATA);
 
 	/* Calculate the offset where decryption starts */
 	const byte* src = src_frame + FIL_PAGE_DATA;
-	byte* dst = dst_frame + FIL_PAGE_DATA;
+	byte* dst = tmp_frame + FIL_PAGE_DATA;
 	uint32 dstlen = 0;
 	ulint srclen = page_size - (FIL_PAGE_DATA + FIL_PAGE_DATA_END);
 
@@ -751,12 +747,12 @@ fil_space_decrypt(
 	to sector boundary is written. */
 	if (!page_compressed) {
 		/* Copy FIL trailer */
-		memcpy(dst_frame + page_size - FIL_PAGE_DATA_END,
+		memcpy(tmp_frame + page_size - FIL_PAGE_DATA_END,
 		       src_frame + page_size - FIL_PAGE_DATA_END,
 		       FIL_PAGE_DATA_END);
 
 		// clear key-version & crypt-checksum from dst
-		memset(dst_frame + FIL_PAGE_FILE_FLUSH_LSN_OR_KEY_VERSION, 0, 8);
+		memset(tmp_frame + FIL_PAGE_FILE_FLUSH_LSN_OR_KEY_VERSION, 0, 8);
 	}
 
 	srv_stats.pages_decrypted.inc();
@@ -765,18 +761,31 @@ fil_space_decrypt(
 }
 
 /******************************************************************
-Decrypt a page */
+Decrypt a page
+@return encrypted page, or original not encrypted page if encryption is
+not needed. */
 UNIV_INTERN
-void
+byte*
 fil_space_decrypt(
 /*==============*/
 	ulint		space,		/*!< in: Fil space id */
-	const byte*	src_frame,	/*!< in: input buffer */
+	byte*		tmp_frame,	/*!< in: temporary buffer */
 	ulint		page_size,	/*!< in: page size */
-	byte*		dst_frame)	/*!< out: output buffer */
+	byte*		src_frame)	/*!< in/out: page buffer */
 {
-	fil_space_decrypt(fil_space_get_crypt_data(space),
-			  src_frame, page_size, dst_frame);
+	bool encrypted = fil_space_decrypt(
+				fil_space_get_crypt_data(space),
+				tmp_frame,
+				page_size,
+				src_frame);
+
+	if (encrypted) {
+		/* Copy the decrypted page back to page buffer, not
+		really any other options. */
+		memcpy(src_frame, tmp_frame, page_size);
+	}
+
+	return src_frame;
 }
 
 /*********************************************************************

storage/xtradb/fil/fil0fil.cc

@@ -6468,14 +6468,19 @@ fil_iterate(
 		for (ulint i = 0; i < n_pages_read; ++i) {
 
 			if (iter.crypt_data != NULL) {
+				ulint size = iter.page_size;
 				bool decrypted = fil_space_decrypt(
-					iter.crypt_data,
-					readptr + i * iter.page_size,    // src
-					iter.page_size,
-					io_buffer + i * iter.page_size); // dst
+							iter.crypt_data,
+							io_buffer + i * size, //dst
+							iter.page_size,
+							readptr + i * size); // src
+
 				if (decrypted) {
 					/* write back unencrypted page */
 					updated = true;
+				} else {
+					/* TODO: remove unnecessary memcpy's */
+					memcpy(io_buffer + i * size, readptr + i * size, size);
 				}
 			}
 

storage/xtradb/include/buf0buf.h

@@ -1477,9 +1477,9 @@ UNIV_INTERN
 byte*
 buf_page_encrypt_before_write(
 /*==========================*/
-	buf_page_t* page, /*!< in/out: buffer page to be flushed */
-	const byte* frame,
-	ulint space_id);
+	buf_page_t*	page,		/*!< in/out: buffer page to be flushed */
+	byte*		frame,		/*!< in: src frame */
+	ulint		space_id);	/*!< in: space id */
 
 /**********************************************************************
 The hook that is called after page is written to disk.

storage/xtradb/include/fil0crypt.h

 /*****************************************************************************
-
+Copyright (C) 2013, 2015, Google Inc. All Rights Reserved.
 Copyright (c) 2015, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
@@ -197,43 +197,45 @@ bool
 fil_space_check_encryption_read(
 /*============================*/
 	ulint space);          /*!< in: tablespace id */
-
-/*********************************************************************
-Encrypt buffer page */
+/******************************************************************
+Decrypt a page
+@return true if page is decrypted, false if not. */
 UNIV_INTERN
-void
-fil_space_encrypt(
+bool
+fil_space_decrypt(
 /*==============*/
-	ulint space,          /*!< in: tablespace id */
-	ulint offset,         /*!< in: page no */
-	lsn_t lsn,            /*!< in: page lsn */
-	const byte* src_frame,/*!< in: page frame */
-	ulint size,           /*!< in: size of data to encrypt */
-	byte* dst_frame);      /*!< in: where to encrypt to */
+	fil_space_crypt_t*	crypt_data,	/*!< in: crypt data */
+	byte*			tmp_frame,	/*!< in: temporary buffer */
+	ulint			page_size,	/*!< in: page size */
+	byte*			src_frame);	/*!< in:out: page buffer */
 
 /*********************************************************************
-Decrypt buffer page */
+Encrypt buffer page
+@return encrypted page, or original not encrypted page if encrypt
+is not needed. */
 UNIV_INTERN
-void
-fil_space_decrypt(
+byte*
+fil_space_encrypt(
 /*==============*/
-	ulint space,          /*!< in: tablespace id */
-	const byte* src_frame,/*!< in: page frame */
-	ulint page_size,      /*!< in: size of data to encrypt */
-	byte* dst_frame);     /*!< in: where to decrypt to */
-
+	ulint	space,		/*!< in: tablespace id */
+	ulint	offset,		/*!< in: page no */
+	lsn_t	lsn,		/*!< in: page lsn */
+	byte*	src_frame,	/*!< in: page frame */
+	ulint	size,		/*!< in: size of data to encrypt */
+	byte*	dst_frame);	/*!< in: where to encrypt to */
 
 /*********************************************************************
 Decrypt buffer page
-@return true if page was encrypted */
+@return decrypted page, or original not encrypted page if decrypt is
+not needed.*/
 UNIV_INTERN
-bool
+byte*
 fil_space_decrypt(
 /*==============*/
-	fil_space_crypt_t* crypt_data, /*!< in: crypt data */
-	const byte* src_frame,/*!< in: page frame */
-	ulint page_size,      /*!< in: page size */
-	byte* dst_frame);     /*!< in: where to decrypt to */
+	ulint	space,		/*!< in: tablespace id */
+	byte*	src_frame,	/*!< in: page frame */
+	ulint	page_size,	/*!< in: size of data to encrypt */
+	byte*	dst_frame);	/*!< in: where to decrypt to */
 
 /*********************************************************************
 fil_space_verify_crypt_checksum