From 0f89617623fed9541ead9497043e907466848a9f Mon Sep 17 00:00:00 2001 From: Tyler Hicks Date: Mon, 15 Apr 2013 16:16:24 -0700 Subject: [PATCH] eCryptfs: Read/write entire page during page IO When reading and writing encrypted pages, perform IO using the entire page all at once rather than 4096 bytes at a time. This only affects architectures where PAGE_CACHE_SIZE is larger than 4096 bytes. Signed-off-by: Tyler Hicks --- fs/ecryptfs/crypto.c | 66 +++++++++++++++++++++----------------------- 1 file changed, 31 insertions(+), 35 deletions(-) diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c index e8976c004669..4185584594f5 100644 --- a/fs/ecryptfs/crypto.c +++ b/fs/ecryptfs/crypto.c @@ -490,6 +490,7 @@ int ecryptfs_encrypt_page(struct page *page) char *enc_extent_virt; struct page *enc_extent_page = NULL; loff_t extent_offset; + loff_t lower_offset; int rc = 0; ecryptfs_inode = page->mapping->host; @@ -503,12 +504,10 @@ int ecryptfs_encrypt_page(struct page *page) "encrypted extent\n"); goto out; } - enc_extent_virt = kmap(enc_extent_page); + for (extent_offset = 0; extent_offset < (PAGE_CACHE_SIZE / crypt_stat->extent_size); extent_offset++) { - loff_t offset; - rc = ecryptfs_encrypt_extent(enc_extent_page, crypt_stat, page, extent_offset); if (rc) { @@ -516,25 +515,24 @@ int ecryptfs_encrypt_page(struct page *page) "rc = [%d]\n", __func__, rc); goto out; } - ecryptfs_lower_offset_for_extent( - &offset, ((((loff_t)page->index) - * (PAGE_CACHE_SIZE - / crypt_stat->extent_size)) - + extent_offset), crypt_stat); - rc = ecryptfs_write_lower(ecryptfs_inode, (enc_extent_virt + - extent_offset * crypt_stat->extent_size), - offset, crypt_stat->extent_size); - if (rc < 0) { - ecryptfs_printk(KERN_ERR, "Error attempting " - "to write lower page; rc = [%d]" - "\n", rc); - goto out; - } + } + + ecryptfs_lower_offset_for_extent(&lower_offset, + page->index * (PAGE_CACHE_SIZE / crypt_stat->extent_size), + crypt_stat); + enc_extent_virt = kmap(enc_extent_page); + rc = ecryptfs_write_lower(ecryptfs_inode, enc_extent_virt, lower_offset, + PAGE_CACHE_SIZE); + kunmap(enc_extent_page); + if (rc < 0) { + ecryptfs_printk(KERN_ERR, + "Error attempting to write lower page; rc = [%d]\n", + rc); + goto out; } rc = 0; out: if (enc_extent_page) { - kunmap(enc_extent_page); __free_page(enc_extent_page); } return rc; @@ -599,6 +597,7 @@ int ecryptfs_decrypt_page(struct page *page) char *enc_extent_virt; struct page *enc_extent_page = NULL; unsigned long extent_offset; + loff_t lower_offset; int rc = 0; ecryptfs_inode = page->mapping->host; @@ -612,26 +611,24 @@ int ecryptfs_decrypt_page(struct page *page) "encrypted extent\n"); goto out; } + + ecryptfs_lower_offset_for_extent(&lower_offset, + page->index * (PAGE_CACHE_SIZE / crypt_stat->extent_size), + crypt_stat); enc_extent_virt = kmap(enc_extent_page); + rc = ecryptfs_read_lower(enc_extent_virt, lower_offset, PAGE_CACHE_SIZE, + ecryptfs_inode); + kunmap(enc_extent_page); + if (rc < 0) { + ecryptfs_printk(KERN_ERR, + "Error attempting to read lower page; rc = [%d]\n", + rc); + goto out; + } + for (extent_offset = 0; extent_offset < (PAGE_CACHE_SIZE / crypt_stat->extent_size); extent_offset++) { - loff_t offset; - - ecryptfs_lower_offset_for_extent( - &offset, ((page->index * (PAGE_CACHE_SIZE - / crypt_stat->extent_size)) - + extent_offset), crypt_stat); - rc = ecryptfs_read_lower((enc_extent_virt + - extent_offset * crypt_stat->extent_size), - offset, crypt_stat->extent_size, - ecryptfs_inode); - if (rc < 0) { - ecryptfs_printk(KERN_ERR, "Error attempting " - "to read lower page; rc = [%d]" - "\n", rc); - goto out; - } rc = ecryptfs_decrypt_extent(page, crypt_stat, enc_extent_page, extent_offset); if (rc) { @@ -642,7 +639,6 @@ int ecryptfs_decrypt_page(struct page *page) } out: if (enc_extent_page) { - kunmap(enc_extent_page); __free_page(enc_extent_page); } return rc; -- 2.39.2