Revert "ecryptfs: modify write path to encrypt page in writepage"

fs/ecryptfs/read_write.c

Index: fs/ecryptfs/read_write.c
diff --git a/fs/ecryptfs/read_write.c b/fs/ecryptfs/read_write.c
index 70902ce56c61f31b7fb5a0b7b06ea2237afde32c..0cc4fafd6552c3d8ddef02e38a81dad96eb6ff6f 100644
--- a/fs/ecryptfs/read_write.c
+++ b/fs/ecryptfs/read_write.c
@@ -44,11 +44,15 @@ int ecryptfs_write_lower(struct inode *ecryptfs_inode, char *data,
 	ssize_t rc;
 
 	inode_info = ecryptfs_inode_to_private(ecryptfs_inode);
+	mutex_lock(&inode_info->lower_file_mutex);
 	BUG_ON(!inode_info->lower_file);
+	inode_info->lower_file->f_pos = offset;
 	fs_save = get_fs();
 	set_fs(get_ds());
-	rc = vfs_write(inode_info->lower_file, data, size, &offset);
+	rc = vfs_write(inode_info->lower_file, data, size,
+		       &inode_info->lower_file->f_pos);
 	set_fs(fs_save);
+	mutex_unlock(&inode_info->lower_file_mutex);
 	mark_inode_dirty_sync(ecryptfs_inode);
 	return rc;
 }
@@ -231,11 +235,15 @@ int ecryptfs_read_lower(char *data, loff_t offset, size_t size,
 	mm_segment_t fs_save;
 	ssize_t rc;
 
+	mutex_lock(&inode_info->lower_file_mutex);
 	BUG_ON(!inode_info->lower_file);
+	inode_info->lower_file->f_pos = offset;
 	fs_save = get_fs();
 	set_fs(get_ds());
-	rc = vfs_read(inode_info->lower_file, data, size, &offset);
+	rc = vfs_read(inode_info->lower_file, data, size,
+		      &inode_info->lower_file->f_pos);
 	set_fs(fs_save);
+	mutex_unlock(&inode_info->lower_file_mutex);
 	return rc;
 }