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Commit d78de618 authored by Tyler Hicks's avatar Tyler Hicks
Browse files

eCryptfs: Merge ecryptfs_encrypt_extent() and ecryptfs_decrypt_extent() 



They are identical except if the src_page or dst_page index is used, so
they can be merged safely if page_index is conditionally assigned.

Signed-off-by: default avatarTyler Hicks <tyhicks@canonical.com>
parent a8ca90e2

fs/ecryptfs/crypto.c

+20 −54
Original line number Diff line number Diff line
@@ -416,28 +416,29 @@ static loff_t lower_offset_for_page(struct ecryptfs_crypt_stat *crypt_stat, 
}



/**

 * ecryptfs_encrypt_extent

 * @enc_extent_page: Allocated page into which to encrypt the data in

 *                   @page

 * crypt_extent

 * @dst_page: The page to write the result into

 * @crypt_stat: crypt_stat containing cryptographic context for the

 *              encryption operation

 * @page: Page containing plaintext data extent to encrypt

 * @src_page: The page to read from

 * @extent_offset: Page extent offset for use in generating IV

 * @op: ENCRYPT or DECRYPT to indicate the desired operation

 *

 * Encrypts one extent of data.

 * Encrypts or decrypts one extent of data.

 *

 * Return zero on success; non-zero otherwise

 */

static int ecryptfs_encrypt_extent(struct page *enc_extent_page,

static int crypt_extent(struct page *dst_page,

			struct ecryptfs_crypt_stat *crypt_stat,

				   struct page *page,

				   unsigned long extent_offset)

			struct page *src_page,

			unsigned long extent_offset, int op)

{

	pgoff_t page_index = op == ENCRYPT ? src_page->index : dst_page->index;

	loff_t extent_base;

	char extent_iv[ECRYPTFS_MAX_IV_BYTES];

	int rc;



	extent_base = (((loff_t)page->index)

	extent_base = (((loff_t)page_index)

		       * (PAGE_CACHE_SIZE / crypt_stat->extent_size));

	rc = ecryptfs_derive_iv(extent_iv, crypt_stat,

				(extent_base + extent_offset));
@@ -447,14 +448,13 @@ static int ecryptfs_encrypt_extent(struct page *enc_extent_page, 
			(unsigned long long)(extent_base + extent_offset), rc);

		goto out;

	}

	rc = crypt_page_offset(crypt_stat, enc_extent_page, page,

	rc = crypt_page_offset(crypt_stat, dst_page, src_page,

			       (extent_offset * crypt_stat->extent_size),

			       crypt_stat->extent_size, extent_iv, ENCRYPT);

			       crypt_stat->extent_size, extent_iv, op);

	if (rc < 0) {

		printk(KERN_ERR "%s: Error attempting to encrypt page with "

		       "page->index = [%ld], extent_offset = [%ld]; "

		       "rc = [%d]\n", __func__, page->index, extent_offset,

		       rc);

		printk(KERN_ERR "%s: Error attempting to crypt page with "

		       "page_index = [%ld], extent_offset = [%ld]; "

		       "rc = [%d]\n", __func__, page_index, extent_offset, rc);

		goto out;

	}

	rc = 0;
@@ -503,8 +503,8 @@ int ecryptfs_encrypt_page(struct page *page) 
	for (extent_offset = 0;

	     extent_offset < (PAGE_CACHE_SIZE / crypt_stat->extent_size);

	     extent_offset++) {

		rc = ecryptfs_encrypt_extent(enc_extent_page, crypt_stat, page,

					     extent_offset);

		rc = crypt_extent(enc_extent_page, crypt_stat, page,

				  extent_offset, ENCRYPT);

		if (rc) {

			printk(KERN_ERR "%s: Error encrypting extent; "

			       "rc = [%d]\n", __func__, rc);
@@ -531,40 +531,6 @@ int ecryptfs_encrypt_page(struct page *page) 
	return rc;

}



static int ecryptfs_decrypt_extent(struct page *page,

				   struct ecryptfs_crypt_stat *crypt_stat,

				   struct page *enc_extent_page,

				   unsigned long extent_offset)

{

	loff_t extent_base;

	char extent_iv[ECRYPTFS_MAX_IV_BYTES];

	int rc;



	extent_base = (((loff_t)page->index)

		       * (PAGE_CACHE_SIZE / crypt_stat->extent_size));

	rc = ecryptfs_derive_iv(extent_iv, crypt_stat,

				(extent_base + extent_offset));

	if (rc) {

		ecryptfs_printk(KERN_ERR, "Error attempting to derive IV for "

			"extent [0x%.16llx]; rc = [%d]\n",

			(unsigned long long)(extent_base + extent_offset), rc);

		goto out;

	}

	rc = crypt_page_offset(crypt_stat, page, enc_extent_page,

			       (extent_offset * crypt_stat->extent_size),

			       crypt_stat->extent_size, extent_iv, DECRYPT);

	if (rc < 0) {

		printk(KERN_ERR "%s: Error attempting to decrypt to page with "

		       "page->index = [%ld], extent_offset = [%ld]; "

		       "rc = [%d]\n", __func__, page->index, extent_offset,

		       rc);

		goto out;

	}

	rc = 0;

out:

	return rc;

}



/**

 * ecryptfs_decrypt_page

 * @page: Page mapped from the eCryptfs inode for the file; data read
@@ -610,8 +576,8 @@ int ecryptfs_decrypt_page(struct page *page) 
	for (extent_offset = 0;

	     extent_offset < (PAGE_CACHE_SIZE / crypt_stat->extent_size);

	     extent_offset++) {

		rc = ecryptfs_decrypt_extent(page, crypt_stat, page,

					     extent_offset);

		rc = crypt_extent(page, crypt_stat, page,

				  extent_offset, DECRYPT);

		if (rc) {

			printk(KERN_ERR "%s: Error encrypting extent; "

			       "rc = [%d]\n", __func__, rc);