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authorTyler Hicks <tyhicks@canonical.com>2013-04-15 16:16:24 -0700
committerTyler Hicks <tyhicks@canonical.com>2013-06-07 17:28:22 -0700
commit0f89617623fed9541ead9497043e907466848a9f (patch)
treea67e630c543c1d44f041acd789ec8420b457065c
parent12003e5b18ca33807b3f9448309ec92184192b85 (diff)
downloadlinux-0f89617623fed9541ead9497043e907466848a9f.tar.bz2
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 <tyhicks@canonical.com>
-rw-r--r--fs/ecryptfs/crypto.c66
1 files 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;