From d78de618962d1e9d28c602e3c75991fe9c94e961 Mon Sep 17 00:00:00 2001 From: Tyler Hicks Date: Sat, 6 Apr 2013 00:08:48 -0700 Subject: [PATCH] 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: Tyler Hicks --- fs/ecryptfs/crypto.c | 74 ++++++++++++-------------------------------- 1 file changed, 20 insertions(+), 54 deletions(-) diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c index 609efc01d5c2..9845d2fd2506 100644 --- a/fs/ecryptfs/crypto.c +++ b/fs/ecryptfs/crypto.c @@ -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, - struct ecryptfs_crypt_stat *crypt_stat, - struct page *page, - unsigned long extent_offset) +static int crypt_extent(struct page *dst_page, + struct ecryptfs_crypt_stat *crypt_stat, + 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 @@ out: 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); -- 2.34.1