From e4bc6522d53b7b8eb02cfac35fd18275fd86269d Mon Sep 17 00:00:00 2001
From: Li Wang <wangli@kylinos.com.cn>
Date: Tue, 30 Oct 2012 19:52:40 +0800
Subject: eCryptfs: Avoid unnecessary disk read and data decryption during
 writing

ecryptfs_write_begin grabs a page from page cache for writing.
If the page contains invalid data, or data older than the
counterpart on the disk, eCryptfs will read out the
corresponing data from the disk into the page, decrypt them,
then perform writing. However, for this page, if the length
of the data to be written into is equal to page size,
that means the whole page of data will be overwritten,
in which case, it does not matter whatever the data were before,
it is beneficial to perform writing directly rather than bothering
to read and decrypt first.

With this optimization, according to our test on a machine with
Intel Core 2 Duo processor, iozone 'write' operation on an existing
file with write size being multiple of page size will enjoy a steady
3x speedup.

Signed-off-by: Li Wang <wangli@kylinos.com.cn>
Signed-off-by: Yunchuan Wen <wenyunchuan@kylinos.com.cn>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>

diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c
index bd1d57f..564a1fa 100644
--- a/fs/ecryptfs/mmap.c
+++ b/fs/ecryptfs/mmap.c
@@ -338,7 +338,8 @@ static int ecryptfs_write_begin(struct file *file,
 			if (prev_page_end_size
 			    >= i_size_read(page->mapping->host)) {
 				zero_user(page, 0, PAGE_CACHE_SIZE);
-			} else {
+				SetPageUptodate(page);
+			} else if (len < PAGE_CACHE_SIZE) {
 				rc = ecryptfs_decrypt_page(page);
 				if (rc) {
 					printk(KERN_ERR "%s: Error decrypting "
@@ -348,8 +349,8 @@ static int ecryptfs_write_begin(struct file *file,
 					ClearPageUptodate(page);
 					goto out;
 				}
+				SetPageUptodate(page);
 			}
-			SetPageUptodate(page);
 		}
 	}
 	/* If creating a page or more of holes, zero them out via truncate.
@@ -499,6 +500,13 @@ static int ecryptfs_write_end(struct file *file,
 		}
 		goto out;
 	}
+	if (!PageUptodate(page)) {
+		if (copied < PAGE_CACHE_SIZE) {
+			rc = 0;
+			goto out;
+		}
+		SetPageUptodate(page);
+	}
 	/* Fills in zeros if 'to' goes beyond inode size */
 	rc = fill_zeros_to_end_of_page(page, to);
 	if (rc) {
-- 
cgit v0.10.2


From 8bbca57cff7f1b1fd046eebd1e9497a00161c2c1 Mon Sep 17 00:00:00 2001
From: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Date: Tue, 21 Aug 2012 10:46:05 +0800
Subject: eCryptfs: fix to use list_for_each_entry_safe() when delete items

Since we will be removing items off the list using list_del() we need
to use a safer version of the list_for_each_entry() macro aptly named
list_for_each_entry_safe(). We should use the safe macro if the loop
involves deletions of items.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
[tyhicks: Fixed compiler err - missing list_for_each_entry_safe() param]
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>

diff --git a/fs/ecryptfs/kthread.c b/fs/ecryptfs/kthread.c
index 809e67d..f1ea610 100644
--- a/fs/ecryptfs/kthread.c
+++ b/fs/ecryptfs/kthread.c
@@ -102,12 +102,12 @@ int __init ecryptfs_init_kthread(void)
 
 void ecryptfs_destroy_kthread(void)
 {
-	struct ecryptfs_open_req *req;
+	struct ecryptfs_open_req *req, *tmp;
 
 	mutex_lock(&ecryptfs_kthread_ctl.mux);
 	ecryptfs_kthread_ctl.flags |= ECRYPTFS_KTHREAD_ZOMBIE;
-	list_for_each_entry(req, &ecryptfs_kthread_ctl.req_list,
-			    kthread_ctl_list) {
+	list_for_each_entry_safe(req, tmp, &ecryptfs_kthread_ctl.req_list,
+				 kthread_ctl_list) {
 		list_del(&req->kthread_ctl_list);
 		*req->lower_file = ERR_PTR(-EIO);
 		complete(&req->done);
-- 
cgit v0.10.2


From 37028758f92d0a3eb74bcfbecf6bc477072e9e28 Mon Sep 17 00:00:00 2001
From: Cong Ding <dinggnu@gmail.com>
Date: Fri, 7 Dec 2012 22:21:56 +0000
Subject: fs/ecryptfs/crypto.c: make ecryptfs_encode_for_filename() static

the function ecryptfs_encode_for_filename() is only used in this file

Signed-off-by: Cong Ding <dinggnu@gmail.com>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>

diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index ea99312..a7b0c2d 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -1935,7 +1935,7 @@ static const unsigned char filename_rev_map[256] = {
  * @src: Source location for the filename to encode
  * @src_size: Size of the source in bytes
  */
-void ecryptfs_encode_for_filename(unsigned char *dst, size_t *dst_size,
+static void ecryptfs_encode_for_filename(unsigned char *dst, size_t *dst_size,
 				  unsigned char *src, size_t src_size)
 {
 	size_t num_blocks;
-- 
cgit v0.10.2